WorldWideScience

Sample records for external battery performance

  1. HST Replacement Battery Initial Performance

    Science.gov (United States)

    Krol, Stan; Waldo, Greg; Hollandsworth, Roger

    2009-01-01

    The Hubble Space Telescope (HST) original Nickel-Hydrogen (NiH2) batteries were replaced during the Servicing Mission 4 (SM4) after 19 years and one month on orbit.The purpose of this presentation is to highlight the findings from the assessment of the initial sm4 replacement battery performance. The batteries are described, the 0 C capacity is reviewed, descriptions, charts and tables reviewing the State Of Charge (SOC) Performance, the Battery Voltage Performance, the battery impedance, the minimum voltage performance, the thermal performance, the battery current, and the battery system recharge ratio,

  2. Performance Targets and External Benchmarking

    DEFF Research Database (Denmark)

    Friis, Ivar; Hansen, Allan; Vámosi, Tamás S.

    Research on relative performance measures, transfer pricing, beyond budgeting initiatives, target costing, piece rates systems and value based management has for decades underlined the importance of external benchmarking in performance management. Research conceptualises external benchmarking...... as a market mechanism that can be brought inside the firm to provide incentives for continuous improvement and the development of competitive advances. However, whereas extant research primarily has focused on the importance and effects of using external benchmarks, less attention has been directed towards...... the conditions upon which the market mechanism is performing within organizations. This paper aims to contribute to research by providing more insight to the conditions for the use of external benchmarking as an element in performance management in organizations. Our study explores a particular type of external...

  3. Artificial neural network simulation of battery performance

    Energy Technology Data Exchange (ETDEWEB)

    O`Gorman, C.C.; Ingersoll, D.; Jungst, R.G.; Paez, T.L.

    1998-12-31

    Although they appear deceptively simple, batteries embody a complex set of interacting physical and chemical processes. While the discrete engineering characteristics of a battery such as the physical dimensions of the individual components, are relatively straightforward to define explicitly, their myriad chemical and physical processes, including interactions, are much more difficult to accurately represent. Within this category are the diffusive and solubility characteristics of individual species, reaction kinetics and mechanisms of primary chemical species as well as intermediates, and growth and morphology characteristics of reaction products as influenced by environmental and operational use profiles. For this reason, development of analytical models that can consistently predict the performance of a battery has only been partially successful, even though significant resources have been applied to this problem. As an alternative approach, the authors have begun development of a non-phenomenological model for battery systems based on artificial neural networks. Both recurrent and non-recurrent forms of these networks have been successfully used to develop accurate representations of battery behavior. The connectionist normalized linear spline (CMLS) network has been implemented with a self-organizing layer to model a battery system with the generalized radial basis function net. Concurrently, efforts are under way to use the feedforward back propagation network to map the {open_quotes}state{close_quotes} of a battery system. Because of the complexity of battery systems, accurate representation of the input and output parameters has proven to be very important. This paper describes these initial feasibility studies as well as the current models and makes comparisons between predicted and actual performance.

  4. Design and analysis of nuclear battery driven by the external neutron source

    International Nuclear Information System (INIS)

    Wang, Sanbing; He, Chaohui

    2014-01-01

    Highlights: • A new type of space nuclear power called NBDEx is investigated. • NBDEx with 252 Cf has better performance than RTG with similar structure. • Its thermal power gets great improvement with increment of fuel enrichment. • The service life of NBDEx is about 2.96 year. • The launch abortion accident analysis fully demonstrates the advantage of NBDEx. - Abstract: Based on the theory of ADS (Accelerator Driven Subcritical reactor), a new type of nuclear battery was investigated, which was composed of a subcritical fission module and an isotope neutron source, called NBDEx (Nuclear Battery Driven by External neutron source). According to the structure of GPHS-RTG (General Purpose Heat Source Radioisotope Thermoelectric Generator), the fuel cell model and fuel assembly model of NBDEx were set up, and then their performances were analyzed with MCNP code. From these results, it was found that the power and power density of NBDEx were almost six times higher than the RTG’s. For fully demonstrating the advantage of NBDEx, the analysis of its impact factors was performed with MCNP code, and its lifetime was also calculated using the Origen code. These results verified that NBDEx was more suitable for the space missions than RTG

  5. Performance Targets and External Market Prices

    DEFF Research Database (Denmark)

    Hansen, Allan; Friis, Ivar; Vámosi, Tamás S.

    2012-01-01

    the implementation of external market information in target setting – well known in transfer pricing, relative performance evaluation, beyond budgeting, target costing, piece rates systems and value based management – relate to challenging motivation and information problem. The analysis and discussion of those...... problems, in particular those related to accounting for the internal performance (that are going to be compared with the external target), calculating the ‘inside’ costs and defining controllability, contributes to the management accounting as well as the piece-rate literature.......In this paper we explore the processes of ‘bringing the market inside the firm’ to set performance targets and benchmark production workers productivity. We analyze attempts to use external suppliers’ bids in target setting in a Danish manufacturing company. The case study illustrates how...

  6. High performance batteries with carbon nanomaterials and ionic liquids

    Science.gov (United States)

    Lu, Wen [Littleton, CO

    2012-08-07

    The present invention is directed to lithium-ion batteries in general and more particularly to lithium-ion batteries based on aligned graphene ribbon anodes, V.sub.2O.sub.5 graphene ribbon composite cathodes, and ionic liquid electrolytes. The lithium-ion batteries have excellent performance metrics of cell voltages, energy densities, and power densities.

  7. High performance anode for advanced Li batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lake, Carla [Applied Sciences, Inc., Cedarville, OH (United States)

    2015-11-02

    The overall objective of this Phase I SBIR effort was to advance the manufacturing technology for ASI’s Si-CNF high-performance anode by creating a framework for large volume production and utilization of low-cost Si-coated carbon nanofibers (Si-CNF) for the battery industry. This project explores the use of nano-structured silicon which is deposited on a nano-scale carbon filament to achieve the benefits of high cycle life and high charge capacity without the consequent fading of, or failure in the capacity resulting from stress-induced fracturing of the Si particles and de-coupling from the electrode. ASI’s patented coating process distinguishes itself from others, in that it is highly reproducible, readily scalable and results in a Si-CNF composite structure containing 25-30% silicon, with a compositionally graded interface at the Si-CNF interface that significantly improve cycling stability and enhances adhesion of silicon to the carbon fiber support. In Phase I, the team demonstrated the production of the Si-CNF anode material can successfully be transitioned from a static bench-scale reactor into a fluidized bed reactor. In addition, ASI made significant progress in the development of low cost, quick testing methods which can be performed on silicon coated CNFs as a means of quality control. To date, weight change, density, and cycling performance were the key metrics used to validate the high performance anode material. Under this effort, ASI made strides to establish a quality control protocol for the large volume production of Si-CNFs and has identified several key technical thrusts for future work. Using the results of this Phase I effort as a foundation, ASI has defined a path forward to commercialize and deliver high volume and low-cost production of SI-CNF material for anodes in Li-ion batteries.

  8. Internal and External Temperature Monitoring of a Li-Ion Battery with Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Susana Novais

    2016-08-01

    Full Text Available The integration of fiber Bragg grating (FBG sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection. The internal sensors recorded temperature variations of 4.0 ± 0.1 °C at 5C and 4.7 ± 0.1 °C at 8C at the center of the active area, and 3.9 ± 0.1 °C at 5C and 4.0 ± 0.1 °C at 8C at the tab-electrode connection, respectively. This study is intended to contribute to detection of a temperature gradient in real time inside a cell, which can determine possible damage in the battery performance when it operates under normal and abnormal operating conditions, as well as to demonstrate the technical feasibility of the integration of in-operando microsensors inside Li-ion cells.

  9. Evaluation Method for Low-Temperature Performance of Lithium Battery

    Science.gov (United States)

    Wang, H. W.; Ma, Q.; Fu, Y. L.; Tao, Z. Q.; Xiao, H. Q.; Bai, H.; Bai, H.

    2018-05-01

    In this paper, the evaluation method for low temperature performance of lithium battery is established. The low temperature performance level was set up to determine the best operating temperature range of the lithium battery using different cathode materials. Results are shared with the consumers for the proper use of lithium battery to make it have a longer service life and avoid the occurrence of early rejection.

  10. Cardiac pacemaker battery discharge after external electrical cardioversion for broad QRS Complex Tachycardia.

    Science.gov (United States)

    Annamaria, Martino; Andrea, Scapigliati; Michela, Casella; Tommaso, Sanna; Gemma, Pelargonio; Antonio, Dello Russo; Roberto, Zamparelli; Stefano, De Paulis; Fulvio, Bellocci; Rocco, Schiavello

    2008-08-01

    External electrical cardioversion or defibrillation may be necessary in patients with implanted cardiac pacemaker (PM) or implantable cardioverter defibrillator (ICD). Sudden discharge of high electrical energy employed in direct current (DC) transthoracic countershock may damage the PM/ICD system resulting in a series of possible device malfunctions. For this reason, when defibrillation or cardioversion must be attempted in a patient with a PM or ICD, some precautions should be taken, particularly in PM dependent patients, in order to prevent damage to the device. We report the case of a 76-year-old woman with a dual chamber PM implanted in the right subclavicular region, who received two consecutive transthoracic DC shocks to treat haemodynamically unstable broad QRS complex tachycardia after cardiac surgery performed with a standard sternotomic approach. Because of the sternal wound and thoracic drainage tubes together with the severe clinical compromise, the anterior paddle was positioned near the pulse generator. At the following PM test, a complete battery discharge was detected.

  11. Mars Express Lithium Ion Batteries Performance Analysis

    Directory of Open Access Journals (Sweden)

    Dudley G.

    2017-01-01

    Full Text Available Now more than 12 years in orbit, Mars Express battery telemetry during some of the deepest discharge cycles has been analysed with the help of the ESTEC lithium ion cell model. The best-fitting model parameter sets were then used to predict the energy that is expected to be available before the battery voltage drops below the minimum value that can support the power bus. This allows mission planners to determine what future power profiles could be supported without risk of entering safe mode. It also gives some more insights into the ageing properties of these batteries.

  12. The Walter Reed performance assessment battery.

    Science.gov (United States)

    Thorne, D R; Genser, S G; Sing, H C; Hegge, F W

    1985-01-01

    This paper describes technical details of a computerized psychological test battery designed for examining the effects of various state-variables on a representative sample of normal psychomotor, perceptual and cognitive tasks. The duration, number and type of tasks can be customized to different experimental needs, and then administered and analyzed automatically, at intervals as short as one hour. The battery can be run on either the Apple-II family of computers or on machines compatible with the IBM-PC.

  13. Data-driven battery product development: Turn battery performance into a competitive advantage.

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal [Voltaiq, Inc.

    2016-04-19

    Poor battery performance is a primary source of user dissatisfaction across a broad range of applications, and is a key bottleneck hindering the growth of mobile technology, wearables, electric vehicles, and grid energy storage. Engineering battery systems is difficult, requiring extensive testing for vendor selection, BMS programming, and application-specific lifetime testing. This work also generates huge quantities of data. This presentation will explain how to leverage this data to help ship quality products faster using fewer resources while ensuring safety and reliability in the field, ultimately turning battery performance into a competitive advantage.

  14. Fully Coupled Simulation of Lithium Ion Battery Cell Performance

    Energy Technology Data Exchange (ETDEWEB)

    Trembacki, Bradley L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Murthy, Jayathi Y. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Scott Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Lithium-ion battery particle-scale (non-porous electrode) simulations applied to resolved electrode geometries predict localized phenomena and can lead to better informed decisions on electrode design and manufacturing. This work develops and implements a fully-coupled finite volume methodology for the simulation of the electrochemical equations in a lithium-ion battery cell. The model implementation is used to investigate 3D battery electrode architectures that offer potential energy density and power density improvements over traditional layer-by-layer particle bed battery geometries. Advancement of micro-scale additive manufacturing techniques has made it possible to fabricate these 3D electrode microarchitectures. A variety of 3D battery electrode geometries are simulated and compared across various battery discharge rates and length scales in order to quantify performance trends and investigate geometrical factors that improve battery performance. The energy density and power density of the 3D battery microstructures are compared in several ways, including a uniform surface area to volume ratio comparison as well as a comparison requiring a minimum manufacturable feature size. Significant performance improvements over traditional particle bed electrode designs are observed, and electrode microarchitectures derived from minimal surfaces are shown to be superior. A reduced-order volume-averaged porous electrode theory formulation for these unique 3D batteries is also developed, allowing simulations on the full-battery scale. Electrode concentration gradients are modeled using the diffusion length method, and results for plate and cylinder electrode geometries are compared to particle-scale simulation results. Additionally, effective diffusion lengths that minimize error with respect to particle-scale results for gyroid and Schwarz P electrode microstructures are determined.

  15. Performance of Sony's Alloy Based Li-Ion Battery

    National Research Council Canada - National Science Library

    Foster, Donald; Wolfenstine, Jeff; Read, Jeffrey; Allen, Jan L

    2008-01-01

    Cells from the new Nexelion battery from Sony Corporation were tested for capacity, low temperature performance, high power capability, high temperature storage, rapid recharge and cycle life on deep discharge...

  16. New Li Battery Chemistry for Improved Performance, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Current state-of-the-art Lithium (Li) or Li-ion systems are unable to meet the performance goals of space-rated rechargeable batteries for many NASA's future robotic...

  17. High Performance Cathodes for Li-Air Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xing, Yangchuan

    2013-08-22

    The overall objective of this project was to develop and fabricate a multifunctional cathode with high activities in acidic electrolytes for the oxygen reduction and evolution reactions for Li-air batteries. It should enable the development of Li-air batteries that operate on hybrid electrolytes, with acidic catholytes in particular. The use of hybrid electrolytes eliminates the problems of lithium reaction with water and of lithium oxide deposition in the cathode with sole organic electrolytes. The use of acid electrolytes can eliminate carbonate formation inside the cathode, making air breathing Li-air batteries viable. The tasks of the project were focused on developing hierarchical cathode structures and bifunctional catalysts. Development and testing of a prototype hybrid Li-air battery were also conducted. We succeeded in developing a hierarchical cathode structure and an effective bifunctional catalyst. We accomplished integrating the cathode with existing anode technologies and made a pouch prototype Li-air battery using sulfuric acid as catholyte. The battery cathodes contain a nanoscale multilayer structure made with carbon nanotubes and nanofibers. The structure was demonstrated to improve battery performance substantially. The bifunctional catalyst developed contains a conductive oxide support with ultra-low loading of platinum and iridium oxides. The work performed in this project has been documented in seven peer reviewed journal publications, five conference presentations, and filing of two U.S. patents. Technical details have been documented in the quarterly reports to DOE during the course of the project.

  18. An improved high-performance lithium-air battery.

    Science.gov (United States)

    Jung, Hun-Gi; Hassoun, Jusef; Park, Jin-Bum; Sun, Yang-Kook; Scrosati, Bruno

    2012-06-10

    Although dominating the consumer electronics markets as the power source of choice for popular portable devices, the common lithium battery is not yet suited for use in sustainable electrified road transport. The development of advanced, higher-energy lithium batteries is essential in the rapid establishment of the electric car market. Owing to its exceptionally high energy potentiality, the lithium-air battery is a very appealing candidate for fulfilling this role. However, the performance of such batteries has been limited to only a few charge-discharge cycles with low rate capability. Here, by choosing a suitable stable electrolyte and appropriate cell design, we demonstrate a lithium-air battery capable of operating over many cycles with capacity and rate values as high as 5,000 mAh g(carbon)(-1) and 3 A g(carbon)(-1), respectively. For this battery we estimate an energy density value that is much higher than those offered by the currently available lithium-ion battery technology.

  19. High Performance Redox Flow Batteries: An Analysis of the Upper Performance Limits of Flow Batteries Using Non-aqueous Solvents

    International Nuclear Information System (INIS)

    Sun, C.-N.; Mench, M.M.; Zawodzinski, T.A.

    2017-01-01

    Redox Flow Batteries (RFBs) are a promising technology for grid-scale electrochemical energy storage. In this work, we use a recently achieved high-performance flow battery performance curve as a basis to assess the maximum achievable performance of a RFB employing non-aqueous solutions as active materials. First we show high performance in a vanadium redox flow battery (VRFB), specifically a limiting situation in which the cell losses are ohmic in nature and derive from electrolyte conductance. Based on that case, we analyze the analogous limiting behavior of non-aqueous (NA) systems using a series of calculations assuming similar ohmic losses, scaled by the relative electrolyte resistances, with a higher voltage redox couple assumed for the NA battery. The results indicate that the NA battery performance is limited by the low electrolyte conductivity to a fraction of the performance of the VRFB. Given the narrow window in which the NARFB offers advantages, even for the most generous limiting assumptions related to performance while ignoring the numerous other disadvantageous aspects of these systems, we conclude that this technology is unlikely under present circumstances to provide practical large-scale energy storage solutions.

  20. The performance of a soluble lead-acid flow battery and its comparison to a static lead-acid battery

    International Nuclear Information System (INIS)

    Zhang, C.P.; Sharkh, S.M.; Li, X.; Walsh, F.C.; Zhang, C.N.; Jiang, J.C.

    2011-01-01

    Highlights: → We compared the electrochemical characteristics of two types of the batteries. → SLAFB shows as good performance as SLAB under the same current density. → The cycle life of two batteries is strongly influenced by the depth of discharge. → The cycle life of SLAFB can be extended by treatment with hydrogen peroxide. - Abstract: The electrochemistry of static lead-acid and soluble lead-acid flow batteries is summarised and the differences between the two batteries are highlighted. A general comparison of the performance of an unoptimised soluble lead-acid flow laboratory cell and a commercial lead-acid battery during charge and discharge is reported. The influence of the depth of discharge on cycle life for both batteries is also considered. The flow battery was found to have a better charge efficiency than the static one, but the cells were found to have comparable energy efficiencies. The self-discharge characteristics of the soluble lead-acid battery were also measured and compared to reported values for a commercial static battery. Some self-discharge of the soluble lead-acid flow battery is observed during prolonged periods on open-circuit but the battery could recover its normal performance after a single charge-discharge cycle.

  1. Performance and Lifetime Limiting Effects in Li-ion Batteries

    DEFF Research Database (Denmark)

    Scipioni, Roberto

    Lithium-ion batteries (LIBs) find widespread use for electricity storage, from portable devices such as smart phones to electric vehicles (EV), because of their high energy density and design flexibility. However, limited lifetime is still a challenge for several LIB materials. Specifically......, the detailed coupling between degradation mechanisms and battery usage is not fully understood, which impede lifetime improvements. To understand the degradation mechanisms and increase the performance of these materials, the development of improved characterization methods is crucial. This PhD thesis focuses...... on the thorough analysis of degradation mechanism in LIBs, trying to relate morphological and structural changes in Lithium-ion battery electrodes to performance degradation observed during electrode cycling. Degradation mechanisms in laboratory scale LFP cathodes were correlated with the degradation mechanisms...

  2. Charging performance of automotive batteries-An underestimated factor influencing lifetime and reliable battery operation

    Science.gov (United States)

    Sauer, Dirk Uwe; Karden, Eckhard; Fricke, Birger; Blanke, Holger; Thele, Marc; Bohlen, Oliver; Schiffer, Julia; Gerschler, Jochen Bernhard; Kaiser, Rudi

    Dynamic charge acceptance and charge acceptance under constant voltage charging conditions are for two reasons essential for lead-acid battery operation: energy efficiency in applications with limited charging time (e.g. PV systems or regenerative braking in vehicles) and avoidance of accelerated ageing due to sulphation. Laboratory tests often use charge regimes which are beneficial for the battery life, but which differ significantly from the operating conditions in the field. Lead-acid batteries in applications with limited charging time and partial-state-of-charge operation are rarely fully charged due to their limited charge acceptance. Therefore, they suffer from sulphation and early capacity loss. However, when appropriate charging strategies are applied most of the lost capacity and thus performance for the user may be recovered. The paper presents several aspects of charging regimes and charge acceptance. Theoretical and experimental investigations show that temperature is the most critical parameter. Full charging within short times can be achieved only at elevated temperatures. A strong dependency of the charge acceptance during charging pulses on the pre-treatment of the battery can be observed, which is not yet fully understood. But these effects have a significant impact on the fuel efficiency of micro-hybrid electric vehicles.

  3. Environmental characteristics comparison of Li-ion batteries and Ni–MH batteries under the uncertainty of cycle performance

    International Nuclear Information System (INIS)

    Yu, Yajuan; Wang, Xiang; Wang, Dong; Huang, Kai; Wang, Lijing; Bao, Liying; Wu, Feng

    2012-01-01

    An environmental impact assessment model for secondary batteries under uncertainty is proposed, which is a combination of the life cycle assessment (LCA), Eco-indicator 99 system and Monte Carlo simulation (MCS). The LCA can describe the environmental impact mechanism of secondary batteries, whereas the cycle performance was simulated through MCS. The composite LCA–MCS model was then carried out to estimate the environmental impact of two kinds of experimental batteries. Under this kind of standard assessment system, a comparison between different batteries could be accomplished. The following results were found: (1) among the two selected batteries, the environmental impact of the Li-ion battery is lower than the nickel–metal hydride (Ni–MH) battery, especially with regards to resource consumption and (2) the lithium ion (Li-ion) battery is less sensitive to cycle uncertainty, its environmental impact fluctuations are small when compared with the selected Ni–MH battery and it is more environmentally friendly. The assessment methodology and model proposed in this paper can also be used for any other secondary batteries and they can be helpful in the development of environmentally friendly secondary batteries.

  4. Performance of batteries for electric vehicles on short and longer term

    NARCIS (Netherlands)

    Gerssen - Gondelach, Sarah|info:eu-repo/dai/nl/355262436; Faaij, André P C|info:eu-repo/dai/nl/10685903X

    2012-01-01

    In this work, the prospects of available and new battery technologies for battery electric vehicles (BEVs) are examined. Five selected battery technologies are assessed on battery performance and cost in the short, medium and long term. Driving cycle simulations are carried out to assess the

  5. Performance of Batteries for electric vehicles on shorter and longer term

    NARCIS (Netherlands)

    Gerssen-Gondelach, S.J.; Faaij, A.P.C.

    2012-01-01

    In this work, the prospects of available and new battery technologies for battery electric vehicles (BEVs) are examined. Five selected battery technologies are assessed on battery performance and cost in the short, medium and long term. Driving cycle simulations are carried out to assess the

  6. High Rate Performing Li-ion Battery

    Science.gov (United States)

    2015-02-09

    journal article will be sufficient in most cases. This document may be as long or as short as needed to give a fair account of the work performed...Klink, J. J. & Moser, J. EPR Study of Vanadium (4+) in the Anatase and Rutile Phases of TiO2. Phys. Rev. B 34, 3060-3068 (1986). 40 Abragam, A

  7. External Innovation Implementation Determinants and Performance Measurement

    DEFF Research Database (Denmark)

    Coates, Matthew; Bals, Lydia

    2013-01-01

    for innovation implementation based on a case study in the pharmaceutical industry. The results of 25 expert interviews and a survey with 67 respondents led to the resulting framework and a corresponding performance measurement system. The results reveal the importance of supporting systems and show differences...

  8. External factors influencing the environmental performance of South African firms

    CSIR Research Space (South Africa)

    Peart, R

    2001-01-01

    Full Text Available This article reviews the external factors that influence environmental performance of companies in South Africa, drawing on international and local literature. After considering factors within the natural, social, economic and institutional...

  9. Batteries

    Directory of Open Access Journals (Sweden)

    Yang Lijuan

    2016-01-01

    Full Text Available Fe3O4/carbon microspheres (Fe3O4/C were prepared by a facile hydrothermal reaction using cellulose and ferric trichloride as precursors. The resultant composite spheres have been investigated as anode materials for the lithium-ion batteries, and they show high capacity and good cycle stability (830mAhg−1 at a current density of 0.1C up to 70 cycles, as well as enhanced rate capability. The excellent electrochemical performance is attributed to the high structural stability and high rate of ionic/electronic conduction arising from the porous character and the synergetic effect of the carbon coated Fe3O4 structure and conductive carbon coating.

  10. Performance of a rapidly-refuelable aluminum-air battery

    Science.gov (United States)

    Levy, D. J.; Hollandsworth, R. P.; Gonzales, E. M.; Littauer, E. L.

    The Al-air battery is being developed to provide an electric vehicle with conventional automobile performance. A rapidly-refuelable, 6-cell battery (200-sq cm electrodes) was evaluated. RX-808 aluminum anodes and air cathodes were used with a flowing alkaline electrolyte. Peak power was found to increase with temperature, decrease with aluminate concentration and be unaffected by electrolyte flow. The best performance was 5.28 kW/sq m peak power density, 2.08 kWh/kg Al energy density and 80 percent coulombic efficiency. Anode refueling is rapid and 100 percent utilization is achieved. Additional evaluation included cathode catalysts, a thermal balance and monitoring electrolyte composition.

  11. High-Performance Na-O2 Batteries Enabled by Oriented NaO2 Nanowires as Discharge Products.

    Science.gov (United States)

    Khajehbashi, S Mohammad B; Xu, Lin; Zhang, Guobin; Tan, Shuangshuang; Zhao, Yan; Wang, Lai-Sen; Li, Jiantao; Luo, Wen; Peng, Dong-Liang; Mai, Liqiang

    2018-06-13

    Na-O 2 batteries are emerging rechargeable batteries due to their high theoretical energy density and abundant resources, but they suffer from sluggish kinetics due to the formation of large-size discharge products with cubic or irregular particle shapes. Here, we report the unique growth of discharge products of NaO 2 nanowires inside Na-O 2 batteries that significantly boosts the performance of Na-O 2 batteries. For this purpose, a high-spin Co 3 O 4 electrocatalyst was synthesized via the high-temperature oxidation of pure cobalt nanoparticles in an external magnetic field. The discharge products of NaO 2 nanowires are 10-20 nm in diameter and ∼10 μm in length, characteristics that provide facile pathways for electron and ion transfer. With these nanowires, Na-O 2 batteries have surpassed 400 cycles with a fixed capacity of 1000 mA h g -1 , an ultra-low over-potential of ∼60 mV during charging, and near-zero over-potential during discharging. This strategy not only provides a unique way to control the morphology of discharge products to achieve high-performance Na-O 2 batteries but also opens up the opportunity to explore growing nanowires in novel conditions.

  12. A Mobility Performance Assessment on Plug-in EV Battery

    Directory of Open Access Journals (Sweden)

    Jay Lee

    2012-12-01

    Full Text Available This paper deals with mobility prediction of LiFeMnPO_4 batteries for an emission-free Electric Vehicle. The data-driven model has been developed based on empirical data from two different road types –highway and local streets –and two different driving modes – aggressive and moderate. Battery State of Charge (SoC can be predicted on any new roads based on the trained model by selecting the drving mode. In this paper, the performance of Adaptive Recurrent Neural Network (ARNN and regression is evaluated using two benchmark data sets. The ARNN model at first estimates the speed profile of the new road based on slope and then both slope and speed is going to be used as the input to estimate battery current and SoC. Through comparison it is found that if ARNN system is appropriately trained, it performs with better accuracy than Regression in both two road types and driving modes. The results show that prediction SoC model follows the Columb-counting SoC according to the road slope.

  13. Battery Performance Modelling ad Simulation: a Neural Network Based Approach

    Science.gov (United States)

    Ottavianelli, Giuseppe; Donati, Alessandro

    2002-01-01

    This project has developed on the background of ongoing researches within the Control Technology Unit (TOS-OSC) of the Special Projects Division at the European Space Operations Centre (ESOC) of the European Space Agency. The purpose of this research is to develop and validate an Artificial Neural Network tool (ANN) able to model, simulate and predict the Cluster II battery system's performance degradation. (Cluster II mission is made of four spacecraft flying in tetrahedral formation and aimed to observe and study the interaction between sun and earth by passing in and out of our planet's magnetic field). This prototype tool, named BAPER and developed with a commercial neural network toolbox, could be used to support short and medium term mission planning in order to improve and maximise the batteries lifetime, determining which are the future best charge/discharge cycles for the batteries given their present states, in view of a Cluster II mission extension. This study focuses on the five Silver-Cadmium batteries onboard of Tango, the fourth Cluster II satellite, but time restrains have allowed so far to perform an assessment only on the first battery. In their most basic form, ANNs are hyper-dimensional curve fits for non-linear data. With their remarkable ability to derive meaning from complicated or imprecise history data, ANN can be used to extract patterns and detect trends that are too complex to be noticed by either humans or other computer techniques. ANNs learn by example, and this is why they can be described as an inductive, or data-based models for the simulation of input/target mappings. A trained ANN can be thought of as an "expert" in the category of information it has been given to analyse, and this expert can then be used, as in this project, to provide projections given new situations of interest and answer "what if" questions. The most appropriate algorithm, in terms of training speed and memory storage requirements, is clearly the Levenberg

  14. Parallel 50 ampere hour nickel cadmium battery performance in the Modular Power Subsystems (MPS)

    Science.gov (United States)

    Webb, D. A.

    1980-01-01

    The thermal performance of 50-ampere-hour, nickel cadmium batteries for use in a modular spacecraft is examined in near-Earth orbit simulation. Battery voltage and temperature profiles for temperature extreme cycles are given and discussed.

  15. Polyanthraquinone-Based Organic Cathode for High-Performance Rechargeable Magnesium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Baofei [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Huang, Jinhua [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Feng, Zhenxing [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zeng, Li [Applied Physics Program, Department of Materials Science and Engineering and Department of Physics and Astronomy, Northwestern University, Evanston IL 60208 USA; He, Meinan [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zhang, Lu [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Vaughey, John T. [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Bedzyk, Michael J. [Applied Physics Program, Department of Materials Science and Engineering and Department of Physics and Astronomy, Northwestern University, Evanston IL 60208 USA; Fenter, Paul [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Zhang, Zhengcheng [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Burrell, Anthony K. [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA; Liao, Chen [Joint Center for Energy Storage Research, Chemical Science and Engineering Division, Argonne National Laboratory, Lemont IL 60439 USA

    2016-05-09

    Two anthraquinone-based polymers aiming at improving the capacity and voltage of magnesium ion batteries, were synthesized and characterized. The excellent battery cycling performance was demonstrated with the electrolyte consisting of magnesium bis(hexamethyldisilazide) and magnesium chloride.

  16. Performance evaluation of Mg-AgCI batteries for underwater propulsion

    OpenAIRE

    K. Venkateswara Rao

    2001-01-01

    Magnesium-silver chloride seawater activated reserve pile-type battery was exclusively used in all underwater vehicles as a source of power due to its high energy density and power density. Various tests have been conducted on fully assembled battery to test its performance, suitability and compatibility. However, it is also essential that the battery is subjected to failure mode studies to understand the limitations of the battery and to analyse the vehicles performance under such sit...

  17. Ability performance of older workers - Internal and external influencing factors

    NARCIS (Netherlands)

    Dittmann-Kohli, F.; Heijden, B.I.J.M. van der

    1996-01-01

    Internal and external factors affecting ability and performance of older employees are being analyzed in a short literature review. Internal factors like physical capacity, sensory capacity, cognitive abilities and general health are reduced with ageing; their effect on performance, however, depends

  18. Control of Internal and External Short Circuits in Lithium Ion and Lithium Batteries, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has identified needs for compact high-energy-density primary and secondary batteries. Lithium and Lithium Ion cells, respectively, are meeting these needs for...

  19. Design and research on discharge performance for aluminum-air battery

    Science.gov (United States)

    Liu, Zu; Zhao, Junhong; Cai, Yanping; Xu, Bin

    2017-01-01

    As a kind of clean energy, the research of aluminum air battery is carried out because aluminum-air battery has advantages of high specific energy, silence and low infrared. Based on the research on operating principle of aluminum-air battery, a novel aluminum-air battery system was designed composed of aluminum-air cell and the circulation system of electrolyte. A system model is established to analyze the polarization curve, the constant current discharge performance and effect of electrolyte concentration on the performance of monomer. The experimental results show that the new energy aluminum-air battery has good discharge performance, which lays a foundation for its application.

  20. High-performance aqueous rechargeable batteries based on zinc ...

    Indian Academy of Sciences (India)

    Administrator

    and environment-friendly energy storage system. Battery is the most versatile ... safe but limited in energy density.2 Therefore, new aque- ous rechargeable battery ... The working electrodes were prepared by coating slur- ries of active material ...

  1. Role of Disorder in Enhancing Lithium-Ion Battery Performance

    DEFF Research Database (Denmark)

    Yue, Yuanzheng; He, W.

    and type of disorder, material performances can be significantly enhanced. Disorder can be tuned by doping, calcination, redox reaction, composition tuning, and so on. Recently we have fabricated a cathode material for lithium ion battery by introducing heterostructure and disorder into the material...... material exhibits the extremely high reversible lithium ion capacity and extraordinary rate capability with high cycling stability at high discharge current. In this presentation we demonstrate that the disorder plays a decisive role in achieving those exceptional electrochemical performances. We describe...... how the disorder affects the migration of both lithium ions and electrons. It is found that both the modified glassy surface and the heterogeneous superlattice structure greatly contribute to the extremely high discharge/charge rates owing to the enhanced storage capacity of lithium ions and ultrafast...

  2. Performance norms for a rhesus monkey neuropsychological testing battery: acquisition and long-term performance.

    Science.gov (United States)

    Weed, M R; Taffe, M A; Polis, I; Roberts, A C; Robbins, T W; Koob, G F; Bloom, F E; Gold, L H

    1999-10-25

    A computerized behavioral battery based upon human neuropsychological tests (CANTAB, CeNeS, Cambridge, UK) has been developed to assess cognitive behaviors of rhesus monkeys. Monkeys reliably performed multiple tasks, providing long-term assessment of changes in a number of behaviors for a given animal. The overall goal of the test battery is to characterize changes in cognitive behaviors following central nervous system (CNS) manipulations. The battery addresses memory (delayed non-matching to sample, DNMS; spatial working memory, using a self-ordered spatial search task, SOSS), attention (intra-/extra-dimensional shift, ID/ED), motivation (progressive-ratio, PR), reaction time (RT) and motor coordination (bimanual task). As with human neuropsychological batteries, different tasks are thought to involve different neural substrates, and therefore performance profiles should assess function in particular brain regions. Monkeys were tested in transport cages, and responding on a touch sensitive computer monitor was maintained by food reinforcement. Parametric manipulations of several tasks demonstrated the sensitivity of performance to increases in task difficulty. Furthermore, the factors influencing difficulty for rhesus monkeys were the same as those shown to affect human performance. Data from this study represent performance of a population of healthy normal monkeys that will be used for comparison in subsequent studies of performance following CNS manipulations such as infection with simian immunodeficiency virus (NeuroAIDS) or drug administration.

  3. Model-based fault diagnosis approach on external short circuit of lithium-ion battery used in electric vehicles

    International Nuclear Information System (INIS)

    Chen, Zeyu; Xiong, Rui; Tian, Jinpeng; Shang, Xiong; Lu, Jiahuan

    2016-01-01

    Highlights: • The characteristics of ESC fault of lithium-ion battery are investigated experimentally. • The proposed method to simulate the electrical behavior of ESC fault is viable. • Ten parameters in the presented fault model were optimized using a DPSO algorithm. • A two-layer model-based fault diagnosis approach for battery ESC is proposed. • The effective and robustness of the proposed algorithm has been evaluated. - Abstract: This study investigates the external short circuit (ESC) fault characteristics of lithium-ion battery experimentally. An experiment platform is established and the ESC tests are implemented on ten 18650-type lithium cells considering different state-of-charges (SOCs). Based on the experiment results, several efforts have been made. (1) The ESC process can be divided into two periods and the electrical and thermal behaviors within these two periods are analyzed. (2) A modified first-order RC model is employed to simulate the electrical behavior of the lithium cell in the ESC fault process. The model parameters are re-identified by a dynamic-neighborhood particle swarm optimization algorithm. (3) A two-layer model-based ESC fault diagnosis algorithm is proposed. The first layer conducts preliminary fault detection and the second layer gives a precise model-based diagnosis. Four new cells are short-circuited to evaluate the proposed algorithm. It shows that the ESC fault can be diagnosed within 5 s, the error between the model and measured data is less than 0.36 V. The effectiveness of the fault diagnosis algorithm is not sensitive to the precision of battery SOC. The proposed algorithm can still make the correct diagnosis even if there is 10% error in SOC estimation.

  4. Towards room-temperature performance for lithium-polymer batteries

    International Nuclear Information System (INIS)

    Kerr, J.B.; Liu, Gao; Curtiss, L.A.; Redfern, Paul C.

    2003-01-01

    Recent work on molecular simulations of the mechanisms of lithium ion conductance has pointed towards two types of limiting process. One has involved the commonly cited segmental motion while the other is related to energy barriers in the solvation shell of polymeric ether oxygens around the lithium ions. Calculations of the barriers to lithium ion migration have provided important indicators as to the best design of the polymer. The theoretical work has coincided with and guided some recent developments on polymer synthesis for lithium batteries. Structural change of the polymer solvation shell has been pursued by the introduction of trimethylene oxide (TMO) units into the polymer. The conductivity measurements on polymers containing TMO unit are encouraging. The architecture of the polymer networks has been varied upon which the solvating groups are attached and significant improvements in sub-ambient performance are observed as a result. However, the above-ambient temperature performance appears controlled by an Arrhenius process that is not completely consistent with the theoretical calculations described here and may indicate the operation of a different mechanism. The new polymers possess significantly lower T g values in the presence of lithium salts, which indicates weaker binding of the lithium ions by the polymers. These properties provide considerable improvement in the transport properties close to the electrode surfaces resulting in decreased impedances at the surfaces both at lithium metal and in composite electrodes. The greater flexibility of the solvation groups combined with appropriate architecture not only has applications in lithium metal-polymer batteries but also in lithium ion liquid and gel systems as well as in fuel cell electrodes

  5. A Nanostructured Composites Thermal Switch Controls Internal and External Short Circuit in Lithium Ion Batteries

    Science.gov (United States)

    McDonald, Robert C.; VanBlarcom, Shelly L.; Kwasnik, Katherine E.

    2013-01-01

    A document discusses a thin layer of composite material, made from nano scale particles of nickel and Teflon, placed within a battery cell as a layer within the anode and/or the cathode. There it conducts electrons at room temperature, then switches to an insulator at an elevated temperature to prevent thermal runaway caused by internal short circuits. The material layer controls excess currents from metal-to-metal or metal-to-carbon shorts that might result from cell crush or a manufacturing defect

  6. Analytical Study of 90Sr Betavoltaic Nuclear Battery Performance Based on p-n Junction Silicon

    International Nuclear Information System (INIS)

    Rahastama, Swastya; Waris, Abdul

    2016-01-01

    Previously, an analytical calculation of 63 Ni p-n junction betavoltaic battery has been published. As the basic approach, we reproduced the analytical simulation of 63 Ni betavoltaic battery and then compared it to previous results using the same design of the battery. Furthermore, we calculated its maximum power output and radiation- electricity conversion efficiency using semiconductor analysis method.Then, the same method were applied to calculate and analyse the performance of 90 Sr betavoltaic battery. The aim of this project is to compare the analytical perfomance results of 90 Sr betavoltaic battery to 63 Ni betavoltaic battery and the source activity influences to performance. Since it has a higher power density, 90 Sr betavoltaic battery yields more power than 63 Ni betavoltaic battery but less radiation-electricity conversion efficiency. However, beta particles emitted from 90 Sr source could travel further inside the silicon corresponding to stopping range of beta particles, thus the 90 Sr betavoltaic battery could be designed thicker than 63 Ni betavoltaic battery to achieve higher conversion efficiency. (paper)

  7. An electric vehicle propulsion system's impact on battery performance: An overview

    Science.gov (United States)

    Bozek, J. M.; Smithrick, J. J.; Cataldo, R. C.; Ewashinka, J. G.

    1980-01-01

    The performance of two types of batteries, lead-acid and nickel-zinc, was measured as a function of the charging and discharging demands anticipated from electric vehicle propulsion systems. The benefits of rapid high current charging were mixed: although it allowed quick charges, the energy efficiency was reduced. For low power (overnight) charging the current wave shapes delivered by the charger to the battery tended to have no effect on the battery cycle life. The use of chopper speed controllers with series traction motors resulted in a significant reduction in the energy available from a battery whenever the motor operates at part load. The demand placed on a battery by an electric vehicle propulsion system containing electrical regenerative braking confirmed significant improvment in short term performance of the battery.

  8. Electrochemical performance of CuNCN for sodium ion batteries and comparison with ZnNCN and lithium ion batteries

    Science.gov (United States)

    Eguia-Barrio, A.; Castillo-Martínez, E.; Klein, F.; Pinedo, R.; Lezama, L.; Janek, J.; Adelhelm, P.; Rojo, T.

    2017-11-01

    Transition metal carbodiimides (TMNCN) undergo conversion reactions during electrochemical cycling in lithium and sodium ion batteries. Micron sized copper and zinc carbodiimide powders have been prepared as single phase as confirmed by PXRD and IR and their thermal stability has been studied in air and nitrogen atmosphere. CuNCN decomposes at ∼250 °C into CuO or Cu while ZnNCN can be stable until 400 °C and 800 °C in air and nitrogen respectively. Both carbodiimides were electrochemically analysed for sodium and lithium ion batteries. The electrochemical Na+ insertion in CuNCN exhibits a relatively high reversible capacity (300 mAh·g-1) which still indicates an incomplete conversion reaction. This incomplete reaction confirmed by ex-situ EPR analysis, is partly due to kinetic limitations as evidenced in the rate capability experiments and in the constant potential measurements. On the other hand, ZnNCN shows incomplete conversion reaction but with good capacity retention and lower hysteresis as negative electrode for sodium ion batteries. The electrochemical performance of these materials is comparable to that of other materials which operate through displacement reactions and is surprisingly better in sodium ion batteries in comparison with lithium ion batteries.

  9. Bending impact on the performance of a flexible Li4Ti5O12-based all-solid-state thin-film battery.

    Science.gov (United States)

    Sepúlveda, Alfonso; Speulmanns, Jan; Vereecken, Philippe M

    2018-01-01

    The growing demand of flexible electronic devices is increasing the requirements of their power sources. The effect of bending in thin-film batteries is still not well understood. Here, we successfully developed a high active area flexible all-solid-state battery as a model system that consists of thin-film layers of Li 4 Ti 5 O 12 , LiPON, and Lithium deposited on a novel flexible ceramic substrate. A systematic study on the bending state and performance of the battery is presented. The battery withstands bending radii of at least 14 mm achieving 70% of the theoretical capacity. Here, we reveal that convex bending has a positive effect on battery capacity showing an average increase of 5.5%, whereas concave bending decreases the capacity by 4% in contrast with recent studies. We show that the change in capacity upon bending may well be associated to the Li-ion diffusion kinetic change through the electrode when different external forces are applied. Finally, an encapsulation scheme is presented allowing sufficient bending of the device and operation for at least 500 cycles in air. The results are meant to improve the understanding of the phenomena present in thin-film batteries while undergoing bending rather than showing improvements in battery performance and lifetime.

  10. Electrical circuit models for performance modeling of Lithium-Sulfur batteries

    DEFF Research Database (Denmark)

    Knap, Vaclav; Stroe, Daniel Ioan; Teodorescu, Remus

    2015-01-01

    emerging technology for various applications, there is a need for Li-S battery performance model; however, developing such models represents a challenging task due to batteries' complex ongoing chemical reactions. Therefore, the literature review was performed to summarize electrical circuit models (ECMs......) used for modeling the performance behavior of Li-S batteries. The studied Li-S pouch cell was tested in the laboratory in order to parametrize four basic ECM topologies. These topologies were compared by analyzing their voltage estimation accuracy values, which were obtained for different battery...... current profiles. Based on these results, the 3 R-C ECM was chosen and the Li-S battery cell discharging performance model with current dependent parameters was derived and validated....

  11. Performance simulation and analysis of a fuel cell/battery hybrid forklift truck

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud; Advani, Suresh G.

    2013-01-01

    The performance of a forklift truck powered by a hybrid system consisting of a PEM fuel cell and a lead acid battery is modeled and investigated by conducting a parametric study. Various combinations of fuel cell size and battery capacity are employed in conjunction with two distinct control...... strategies to study their effect on hydrogen consumption and battery state-of-charge for two drive cycles characterized by different operating speeds and forklift loads. The results show that for all case studies, the combination of a 110 cell stack with two strings of 55 Ah batteries is the most economical...

  12. Performance features of 22-cell, 19Ah single pressure vessel nickel hydrogen battery

    Energy Technology Data Exchange (ETDEWEB)

    Rao, G.M.; Vaidyanathan, H.

    1996-02-01

    Two 22-cells 19Ah Nickel-Hydrogen (Ni-H2) Single Pressure Vessel (SPV) Qual batteries, one each from EPI/Joplin and EPI/Butler, were designed and procured. The two batteries differ in the cell encapsulation technology, stack preload, and activation procedure. Both the Butler and Joplin batteries met the specified requirements when subjected to qualification testing and completed 2100 and 1300 LEO cycles respectively, with nominal performance. This paper discusses advantages, design features, testing procedures, and results of the two single pressure vessel Ni-H2 batteries.

  13. Performance features of 22-cell, 19Ah single pressure vessel nickel hydrogen battery

    Science.gov (United States)

    Rao, Gopalakrishna M.; Vaidyanathan, Hari

    1996-01-01

    Two 22-cells 19Ah Nickel-Hydrogen (Ni-H2) Single Pressure Vessel (SPV) Qual batteries, one each from EPI/Joplin and EPI/Butler, were designed and procured. The two batteries differ in the cell encapsulation technology, stack preload, and activation procedure. Both the Butler and Joplin batteries met the specified requirements when subjected to qualification testing and completed 2100 and 1300 LEO cycles respectively, with nominal performance. This paper discusses advantages, design features, testing procedures, and results of the two single pressure vessel Ni-H2 batteries.

  14. Control of internal and external short circuits in lithium batteries using a composite thermal switch

    Science.gov (United States)

    Mcdonald, Robert C.; Pickett, Jerome; Goebel, Franz

    1991-01-01

    A composite material has been developed, consisting of a blend of metal and fluorocarbon particles, which behaves as an electronic conductor at room temperature and which abruptly becomes an insulator at a predetermined temperature. This switching behavior results from the difference in thermal expansion coefficients between the conductive and non-conductive portions of the composite. This material was applied as a thin film between the carbon cathode in Li/SOCl2 cells, and the metallic cathode current collector. Using test articles incorporating this feature it was shown that lithium cells externally heated or internally heated during a short circuit lost rate capability and the ability to overheat well below the melting point of lithium (180 C). Thus, during an internal or external cell short circuit, the potential for thermal runaway involving reactions of molten lithium is avoided.

  15. Performance Modeling of a Vanadium Redox Flow Battery during Discharging

    International Nuclear Information System (INIS)

    Yang, W.W.; He, Y.L.; Li, Y.S.

    2015-01-01

    A two-dimensional quasi-steady-state model is presented to simulate coupled mass-species-charge transfer and electrochemical reactions in all vanadium redox flow battery. Emphasis is located on examining the influences of applied current density, initial vanadium concentration, initial acid concentration and electrolyte flow rate on overpotentials in both electrodes, ohmic loss in electrolyte phase as well as battery discharging voltage. It is indicated that overpotential in negative electrode is the dominant factor causing the loss of battery discharging voltage at relatively lower or higher state of charge, while ohmic loss in electrolyte phase is dominant when discharging at moderate state of charge. Increasing initial vanadium concentration, the battery discharging voltage is significantly increased due to the reduced overpotentials in both electrodes. With the increase in initial acid concentration, the battery discharging voltage is also obviously increased because of increased open circuit voltage and decreased ohmic loss in electrolyte phase. As the electrolyte flow rate increases, the total discharging time is extended due to the retarded concentration polarization and the battery discharging voltage is obviously increased at lower state of charge

  16. Evaluation of Lithium-ion Battery Second Life Performance and Degradation

    DEFF Research Database (Denmark)

    Martinez-Laserna, Egoitz; Sarasketa-Zabala, Elixabet; Stroe, Daniel Loan

    2016-01-01

    the effects of lithium-ion (Li-ion) battery State of Health (SOH) and ageing history over the second life performance on two different applications: a residential demand management application and a power smoothing renewable integration application. The performance and degradation of second life batteries......Reusing electric vehicle batteries once they have been retired from the automotive application is stated as one of the possible solutions to reduce electric vehicle costs. Many publications in the literature have analyzed the economic viability of such a solution, and some car manufacturers have...... recently started running several projects to demonstrate the technical viability of the so-called battery second life. Nevertheless, the performance and degradation of second life batteries remain an unknown topic and one of the biggest gaps in the literature. The present work aims at evaluating...

  17. High-performance rechargeable batteries with fast solid-state ion conductors

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.

    2017-06-27

    A high-performance rechargeable battery using ultra-fast ion conductors. In one embodiment the rechargeable battery apparatus includes an enclosure, a first electrode operatively connected to the enclosure, a second electrode operatively connected to the enclosure, a nanomaterial in the enclosure, and a heat transfer unit.

  18. Improving the Performance of Lithium–Sulfur Batteries by Conductive Polymer Coating

    KAUST Repository

    Yang, Yuan; Yu, Guihua; Cha, Judy J.; Wu, Hui; Vosgueritchian, Michael; Yao, Yan; Bao, Zhenan; Cui, Yi

    2011-01-01

    Ah/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li-S batteries and can be applicable to other electrode materials in lithium ion batteries

  19. Modified performance test of vented lead acid batteries for stationary applications

    International Nuclear Information System (INIS)

    Uhlir, K.W.; Fletcher, R.J.

    1995-01-01

    The concept of a modified performance test for vented lead acid batteries in stationary applications has been developed by the IEEE Battery Working Group. The modified performance test is defined as a test in the ''as found'' condition of the battery capacity and its ability to provide a high rate, short duration load (usually the highest rate of the duty cycle) that will confirm the battery's ability to meet the critical period of the load duty cycle, in addition to determining its percentage of rated capacity. This paper will begin by reviewing performance and service test requirements and concerns associated with both types of tests. The paper will then discuss the rationale for developing a modified performance test along with the benefits that can be derived from performing a modified performance test in lieu of a capacity test and/or a service test. The paper will conclude with an example on how to apply a modified performance test and test acceptance criteria

  20. International Space Station Nickel-Hydrogen Battery Start-Up and Initial Performance

    Science.gov (United States)

    Cohen, Fred; Dalton, Penni J.

    2001-01-01

    International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will describe the battery hardware configuration, operation, and role in providing power to the main power system of the ISS. We will also discuss initial battery start-up and performance data.

  1. Strategies toward High-Performance Cathode Materials for Lithium-Oxygen Batteries.

    Science.gov (United States)

    Wang, Kai-Xue; Zhu, Qian-Cheng; Chen, Jie-Sheng

    2018-05-11

    Rechargeable aprotic lithium (Li)-O 2 batteries with high theoretical energy densities are regarded as promising next-generation energy storage devices and have attracted considerable interest recently. However, these batteries still suffer from many critical issues, such as low capacity, poor cycle life, and low round-trip efficiency, rendering the practical application of these batteries rather sluggish. Cathode catalysts with high oxygen reduction reaction (ORR) and evolution reaction activities are of particular importance for addressing these issues and consequently promoting the application of Li-O 2 batteries. Thus, the rational design and preparation of the catalysts with high ORR activity, good electronic conductivity, and decent chemical/electrochemical stability are still challenging. In this Review, the strategies are outlined including the rational selection of catalytic species, the introduction of a 3D porous structure, the formation of functional composites, and the heteroatom doping which succeeded in the design of high-performance cathode catalysts for stable Li-O 2 batteries. Perspectives on enhancing the overall electrochemical performance of Li-O 2 batteries based on the optimization of the properties and reliability of each part of the battery are also made. This Review sheds some new light on the design of highly active cathode catalysts and the development of high-performance lithium-O 2 batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Extensive EIS characterization of commercially available lithium polymer battery cell for performance modelling

    DEFF Research Database (Denmark)

    Stanciu, Tiberiu; Stroe, Daniel Loan; Teodorescu, Remus

    2015-01-01

    or degradation of an electrochemical system. Used for Lithium-ion (Li-ion) batteries, this method allows for a fast and accurate assessment of the battery's impedance at any working point, without modifying the state of the battery. The influence of the operating conditions, state of charge (SOC) and temperature...... on the performance of a commercially available 53 Ah Lithium polymer battery cell, manufactured by Kokam Co. Ltd., is investigated in laboratory experiments, at its beginning of life, by means of EIS. A data fitting algorithm was used to obtain the parameter values for the proposed equivalent electrical circuit......, which was further selected for the development of an accurate EIS based performance model for the chosen Li-ion battery cell....

  3. High-Performance Lithium-Air Battery with a Coaxial-Fiber Architecture.

    Science.gov (United States)

    Zhang, Ye; Wang, Lie; Guo, Ziyang; Xu, Yifan; Wang, Yonggang; Peng, Huisheng

    2016-03-24

    The lithium-air battery has been proposed as the next-generation energy-storage device with a much higher energy density compared with the conventional lithium-ion battery. However, lithium-air batteries currently suffer enormous problems including parasitic reactions, low recyclability in air, degradation, and leakage of liquid electrolyte. Besides, they are designed into a rigid bulk structure that cannot meet the flexible requirement in the modern electronics. Herein, for the first time, a new family of fiber-shaped lithium-air batteries with high electrochemical performances and flexibility has been developed. The battery exhibited a discharge capacity of 12,470 mAh g(-1) and could stably work for 100 cycles in air; its electrochemical performances were well maintained under bending and after bending. It was also wearable and formed flexible power textiles for various electronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Long Term Analysis of Adaptive Low-Power Instrument Platform Power and Battery Performance

    Science.gov (United States)

    Edwards, T.; Bowman, J. R.; Clauer, C. R.

    2017-12-01

    Operation of the Autonomous Adaptive Low-Power Instrument Platform (AAL-PIP) by the Magnetosphere-Ionosphere Science Team (MIST) at Virginia Tech has been ongoing for about 10 years. These instrument platforms are deployed on the East Antarctic Plateau in remote locations that are difficult to access regularly. The systems have been designed to operate unattended for at least 5 years. During the Austral summer, the systems charge batteries using solar panels and power is provided by the batteries during the winter months. If the voltage goes below a critical level, the systems go into hibernation and wait for voltage from the solar panels to initiate a restart sequence to begin operation and battery charging. Our first system was deployed on the East Antarctic Plateau in 2008 and we report here on an analysis of the power and battery performance over multiple years and provide an estimate for how long these systems can operate before major battery maintenance must be performed.

  5. Analytical performance specifications for external quality assessment - definitions and descriptions.

    Science.gov (United States)

    Jones, Graham R D; Albarede, Stephanie; Kesseler, Dagmar; MacKenzie, Finlay; Mammen, Joy; Pedersen, Morten; Stavelin, Anne; Thelen, Marc; Thomas, Annette; Twomey, Patrick J; Ventura, Emma; Panteghini, Mauro

    2017-06-27

    External Quality Assurance (EQA) is vital to ensure acceptable analytical quality in medical laboratories. A key component of an EQA scheme is an analytical performance specification (APS) for each measurand that a laboratory can use to assess the extent of deviation of the obtained results from the target value. A consensus conference held in Milan in 2014 has proposed three models to set APS and these can be applied to setting APS for EQA. A goal arising from this conference is the harmonisation of EQA APS between different schemes to deliver consistent quality messages to laboratories irrespective of location and the choice of EQA provider. At this time there are wide differences in the APS used in different EQA schemes for the same measurands. Contributing factors to this variation are that the APS in different schemes are established using different criteria, applied to different types of data (e.g. single data points, multiple data points), used for different goals (e.g. improvement of analytical quality; licensing), and with the aim of eliciting different responses from participants. This paper provides recommendations from the European Federation of Laboratory Medicine (EFLM) Task and Finish Group on Performance Specifications for External Quality Assurance Schemes (TFG-APSEQA) and on clear terminology for EQA APS. The recommended terminology covers six elements required to understand APS: 1) a statement on the EQA material matrix and its commutability; 2) the method used to assign the target value; 3) the data set to which APS are applied; 4) the applicable analytical property being assessed (i.e. total error, bias, imprecision, uncertainty); 5) the rationale for the selection of the APS; and 6) the type of the Milan model(s) used to set the APS. The terminology is required for EQA participants and other interested parties to understand the meaning of meeting or not meeting APS.

  6. Performance calculations for battery power supplies as laboratory research tools

    International Nuclear Information System (INIS)

    Scanlon, J.J.; Rolader, G.E.; Jamison, K.A.; Petresky, H.

    1991-01-01

    Electromagnetic Launcher (EML) research at the Air Force Armament Laboratory, Hypervelocity Launcher Branch (AFATL/SAH), Eglin AFB, has focused on developing the technologies required for repetitively launching several kilogram payloads to high velocities. Previous AFATL/SAH experiments have been limited by the available power supply resulting in small muzzle energies on the order of 100's of kJ. In an effort to advance the development of EML's, AFATL/SAH has designed and constructed a battery power supply (BPS) capable of providing several mega-Amperes of current for several seconds. This system consists of six modules each containing 2288 automotive batteries which may be connected in two different series - parallel arrangements. In this paper the authors define the electrical characteristics of the AFATL Battery Power supply at the component level

  7. High-performance lithium battery anodes using silicon nanowires.

    Science.gov (United States)

    Chan, Candace K; Peng, Hailin; Liu, Gao; McIlwrath, Kevin; Zhang, Xiao Feng; Huggins, Robert A; Cui, Yi

    2008-01-01

    There is great interest in developing rechargeable lithium batteries with higher energy capacity and longer cycle life for applications in portable electronic devices, electric vehicles and implantable medical devices. Silicon is an attractive anode material for lithium batteries because it has a low discharge potential and the highest known theoretical charge capacity (4,200 mAh g(-1); ref. 2). Although this is more than ten times higher than existing graphite anodes and much larger than various nitride and oxide materials, silicon anodes have limited applications because silicon's volume changes by 400% upon insertion and extraction of lithium which results in pulverization and capacity fading. Here, we show that silicon nanowire battery electrodes circumvent these issues as they can accommodate large strain without pulverization, provide good electronic contact and conduction, and display short lithium insertion distances. We achieved the theoretical charge capacity for silicon anodes and maintained a discharge capacity close to 75% of this maximum, with little fading during cycling.

  8. Effect of polysulfone concentration on the performance of membrane-assisted lead acid battery

    Directory of Open Access Journals (Sweden)

    Ahmad Fauzi Ismail

    2002-11-01

    Full Text Available The application of lead acid battery in tropical countries normally faces the problem of water decomposition. This phenomenon is due to the factor of charge-discharge reaction in the battery and heat accumulation caused by hot tropical climate and heat generated from engine compartment. The objective of this study is to analyze the effect of polysulfone concentration on the performance of membrane-assisted lead-acid battery. Gas separation membranes, prepared through wet-dry phase inversion method and using various polysulfone concentrated formulations, were applied on the battery vent holes, for the purpose of preventing electrolyte from evaporating to the atmosphere. The best membrane, which retains the most electrolyte, will be chosen to be applied on the soon-to-be-developed “membrane-assisted maintenance- free battery”. This maintenance-free battery will need no topping up of deionized water every time the electrolyte level goes low.

  9. Reference Performance Test Methodology for Degradation Assessment of Lithium-Sulfur Batteries

    DEFF Research Database (Denmark)

    Knap, Vaclav; Stroe, Daniel-Ioan; Purkayastha, Rajlakshmi

    2018-01-01

    Lithium-Sulfur (Li-S) is an emerging battery technology receiving a growing amount of attention due to its potentially high gravimetric energy density, safety, and low production cost. However, there are still some obstacles preventing its swift commercialization. Li-S batteries are driven...... by different electrochemical processes than commonly used Lithium-ion batteries, which often results in very different behavior. Therefore, the testing and modeling of these systems have to be adjusted to reflect their unique behavior and to prevent possible bias. A methodology for a Reference Performance Test...... (RPT) for the Li-S batteries is proposed in this study to point out Li-S battery features and provide guidance to users how to deal with them and possible results into standardization. The proposed test methodology is demonstrated for 3.4 Ah Li-S cells aged under different conditions....

  10. Ionic liquid as an electrolyte additive for high performance lead-acid batteries

    Science.gov (United States)

    Deyab, M. A.

    2018-06-01

    The performance of lead-acid battery is improved in this work by inhibiting the corrosion of negative battery electrode (lead) and hydrogen gas evolution using ionic liquid (1-ethyl-3-methylimidazolium diethyl phosphate). The results display that the addition of ionic liquid to battery electrolyte (5.0 M H2SO4 solution) suppresses the hydrogen gas evolution to very low rate 0.049 ml min-1 cm-2 at 80 ppm. Electrochemical studies show that the adsorption of ionic liquid molecules on the lead electrode surface leads to the increase in the charge transfer resistance and the decrease in the double layer capacitance. I also notice a noteworthy improvement of battery capacity from 45 mAh g-1 to 83 mAh g-1 in the presence of ionic liquid compound. Scanning electron microscopy and energy dispersive X-ray analysis confirm the adsorption of ionic liquid molecules on the battery electrode surface.

  11. Binary iron sulfides as anode materials for rechargeable batteries: Crystal structures, syntheses, and electrochemical performance

    Science.gov (United States)

    Xu, Qian-Ting; Li, Jia-Chuang; Xue, Huai-Guo; Guo, Sheng-Ping

    2018-03-01

    Effective utilization of energy requires the storage and conversion device with high ability. For well-developed lithium ion batteries (LIBs) and highly developing sodium ion batteries (SIBs), this ability especially denotes to high energy and power densities. It's believed that the capacity of a full cell is mainly contributed by anode materials. So, to develop inexpensive anode materials with high capacity are meaningful for various rechargeable batteries' better applications. Iron is a productive element in the crust, and its oxides, sulfides, fluorides, and oxygen acid salts are extensively investigated as electrode materials for batteries. In view of the importance of electrode materials containing iron, this review summarizes the recent achievements on various binary iron sulfides (FeS, FeS2, Fe3S4, and Fe7S8)-type electrodes for batteries. The contents are mainly focused on their crystal structures, synthetic methods, and electrochemical performance. Moreover, the challenges and some improvement strategies are also discussed.

  12. Performance Model for High-Power Lithium Titanate Oxide Batteries based on Extended Characterization Tests

    DEFF Research Database (Denmark)

    Stroe, Ana-Irina; Swierczynski, Maciej Jozef; Stroe, Daniel Ioan

    2015-01-01

    Lithium-ion (Li-ion) batteries are found nowadays not only in portable/consumer electronics but also in more power demanding applications, such as stationary renewable energy storage, automotive and back-up power supply, because of their superior characteristics in comparison to other energy...... storage technologies. Nevertheless, prior to be used in any of the aforementioned application, a Li-ion battery cell must be intensively characterized and its behavior needs to be understood. This can be realized by performing extended laboratory characterization tests and developing Li-ion battery...... performance models. Furthermore, accurate performance models are necessary in order to analyze the behavior of the battery cell under different mission profiles, by simulation; thus, avoiding time and cost demanding real life tests. This paper presents the development and the parametrization of a performance...

  13. International Space Station Nickel-Hydrogen Battery On-Orbit Performance

    Science.gov (United States)

    Dalton, Penni; Cohen, Fred

    2002-01-01

    International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35 percent depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after eighteen months of cycling.

  14. Update on International Space Station Nickel-Hydrogen Battery On-Orbit Performance

    Science.gov (United States)

    Dalton, Penni; Cohen, Fred

    2003-01-01

    International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty-eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 (Port) Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will discuss the battery performance data after two and a half years of cycling.

  15. Lithium-ion battery performance improvement based on capacity recovery exploitation

    International Nuclear Information System (INIS)

    Eddahech, Akram; Briat, Olivier; Vinassa, Jean-Michel

    2013-01-01

    Highlights: •Experiments on combined power-cycling/calendar aging of high-power lithium battery. •Recovery phenomenon on battery capacity when we stop power-cycling. •Full discharge at rest time is a potential source for battery life prolongation. •Temperature impact on capacity recovery and battery aging. -- Abstract: In this work, the performance recovery phenomenon when aging high-power lithium-ion batteries used in HEV application is highlighted. This phenomenon consists in the increase on the battery capacity when power-cycling is stopped. The dependency of this phenomenon on the stop-SOC value is demonstrated. Keeping battery at a fully discharged state preserves a large amount of charge from the SEI-electrolyte interaction when they are in the positive electrode during rest time. Results from power cycling and combined aging, calendar/power-cycling, of a 12 A h-commercialized lithium-ion battery, at two temperatures (45 °C and 55 °C), are presented and obtained results are discussed

  16. Selection of the battery pack parameters for an electric vehicle based on performance requirements

    Science.gov (United States)

    Koniak, M.; Czerepicki, A.

    2017-06-01

    Each type of vehicle has specific power requirements. Some require a rapid charging, other make long distances between charges, but a common feature is the longest battery life time. Additionally, the battery is influenced by factors such as temperature, depth of discharge and the operation current. The article contain the parameters of chemical cells that should be taken into account during the design of the battery for a specific application. This is particularly important because the batteries are not properly matched and can wear prematurely and cause an additional costs. The method of selecting the correct cell type should take previously discussed features and operating characteristics of the vehicle into account. The authors present methods of obtaining such characteristics along with their assessment and examples. Also there has been described an example of the battery parameters selection based on design assumptions of the vehicle and the expected performance characteristics. Selecting proper battery operating parameters is important due to its impact on the economic result of investments in electric vehicles. For example, for some Li-Ion technologies, the earlier worn out of batteries in a fleet of cruise boats or buses having estimated lifetime of 10 years is not acceptable, because this will cause substantial financial losses for the owner of the rolling stock. The presented method of choosing the right cell technology in the selected application, can be the basis for making the decision on future battery technical parameters.

  17. Datasheet-based modeling of Li-Ion batteries

    DEFF Research Database (Denmark)

    Barreras, Jorge Varela; Schaltz, Erik; Andreasen, Søren Juhl

    2012-01-01

    Researchers and developers use battery models in order to predict the performance of batteries depending on external and internal conditions, such as temperature, C-rate, Depth-of-Discharge (DoD) or State-of-Health (SoH). Most battery models proposed in the literature require specific laboratory...

  18. Effect of tariffs on the performance and economic benefits of PV-coupled battery systems

    International Nuclear Information System (INIS)

    Parra, David; Patel, Martin K.

    2016-01-01

    Highlights: • Pb-acid and Li-ion batteries are compared under three different retail tariffs. • The battery ageing, i.e. capacity and discharge capability reduction is simulated. • A dynamic tariff (1-h resolution) increases the battery discharge value up to 28%. • A Li-ion cost of 375 CHF/kW h is required for Geneva for PV energy time-shift. • This requirement becomes 500 CHF/kW h if demand peak-shaving is also performed. - Abstract: The use of batteries in combination with PV systems in single homes is expected to become a widely applied energy storage solution. Since PV system cost is decreasing and the electricity market is constantly evolving there is marked interest in understanding the performance and economic benefits of adding battery systems to PV generation under different retail tariffs. The performance of lead-acid (PbA) and lithium-ion (Li-ion) battery systems in combination with PV generation for a single home in Switzerland is studied using a time-dependant analysis. Firstly, the economic benefits of the two battery types are analysed for three different types of tariffs, i.e. a dynamic tariff based on the wholesale market (one price per hour for every day of the year), a flat rate and time-of-use tariff with two periods. Secondly, the reduction of battery capacity and annual discharge throughout the battery lifetime are simulated for PbA and Li-ion batteries. It was found that despite the levelised value of battery systems reaches up to 28% higher values with the dynamic tariff compared to the flat rate tariff, the levelised cost increases by 94% for the dynamic tariff, resulting in lower profitability. The main reason for this is the reduction of equivalent full cycles performed with by battery systems with the dynamic tariff. Economic benefits also depend on the regulatory context and Li-ion battery systems were able to achieve internal rate of return (IRR) up to 0.8% and 4.3% in the region of Jura (Switzerland) and Germany due to

  19. Experimental investigation on the dynamic performance of a hybrid PEM fuel cell/battery system for lightweight electric vehicle application

    International Nuclear Information System (INIS)

    Tang, Yong; Yuan, Wei; Pan, Minqiang; Wan, Zhenping

    2011-01-01

    A hybrid system combining a 2 kW air-blowing proton exchange membrane fuel cell (PEMFC) stack and a lead-acid battery pack is developed for a lightweight cruising vehicle. The dynamic performances of this PEMFC system with and without the assistance of the batteries are systematically investigated in a series of laboratory and road tests. The stack current and voltage have timely dynamic responses to the load variations. Particularly, the current overshoot and voltage undershoot both happen during the step-up load tests. These phenomena are closely related to the charge double-layer effect and the mass transfer mechanisms such as the water and gas transport and distribution in the fuel cell. When the external load is beyond the range of the fuel cell system, the battery immediately participates in power output with a higher transient discharging current especially in the accelerating and climbing processes. The DC-DC converter exhibits a satisfying performance in adaptive modulation. It helps rectify the voltage output in a rigid manner and prevent the fuel cell system from being overloaded. The dynamic responses of other operating parameters such as the anodic operating pressure and the inlet and outlet temperatures are also investigated. The results show that such a hybrid system is able to dynamically satisfy the vehicular power demand.

  20. Performance of a vanadium redox flow battery with and without flow fields

    International Nuclear Information System (INIS)

    Xu, Q.; Zhao, T.S.; Zhang, C.

    2014-01-01

    Highlights: • The performances of a VRFB with/without flow fields are compared. • The respective maximum power efficiency occurs at different flow rates. • The battery with flow fields Exhibits 5% higher energy efficiency. - Abstract: A flow field is an indispensable component for fuel cells to macroscopically distribute reactants onto electrodes. However, it is still unknown whether flow fields are also required in all-vanadium redox flow batteries (VRFBs). In this work, the performance of a VRFB with flow fields is analyzed and compared with the performance of a VRFB without flow fields. It is demonstrated that the battery with flow fields has a higher discharge voltage at higher flow rates, but exhibits a larger pressure drop. The maximum power-based efficiency occurs at different flow rates for the both batteries with and without flow fields. It is found that the battery with flow fields Exhibits 5% higher energy efficiency than the battery without flow fields, when operating at the flow rates corresponding to each battery's maximum power-based efficiency. Therefore, the inclusion of flow fields in VRFBs can be an effective approach for improving system efficiency

  1. Ultra-thin lithium micro-batteries. Performances and applications; Microaccumulateurs ultra minces au lithium. Performances et applications

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M.; Terrat, J.P. [Hydromecanique et frottement (HEF), 42 - Andrezieux Boutheon (France); Levasseur, A.; Vinatier, P.; Meunier, G. [Centre National de la Recherche Scientifique (CNRS), 33 - Talence (France). Institut de Chimie de la Matiere Condensee et Physique de Bordeaux

    1996-12-31

    This short paper (abstract) describes the characteristics and performances of prototypes of ultra-thin lithium micro-batteries (thickness < 0.2 mm) which can be incorporated into microelectronic circuits. (J.S.)

  2. Ultra-thin lithium micro-batteries. Performances and applications; Microaccumulateurs ultra minces au lithium. Performances et applications

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M; Terrat, J P [Hydromecanique et frottement (HEF), 42 - Andrezieux Boutheon (France); Levasseur, A; Vinatier, P; Meunier, G [Centre National de la Recherche Scientifique (CNRS), 33 - Talence (France). Institut de Chimie de la Matiere Condensee et Physique de Bordeaux

    1997-12-31

    This short paper (abstract) describes the characteristics and performances of prototypes of ultra-thin lithium micro-batteries (thickness < 0.2 mm) which can be incorporated into microelectronic circuits. (J.S.)

  3. Performance and cost of materials for lithium-based rechargeable automotive batteries

    Science.gov (United States)

    Schmuch, Richard; Wagner, Ralf; Hörpel, Gerhard; Placke, Tobias; Winter, Martin

    2018-04-01

    It is widely accepted that for electric vehicles to be accepted by consumers and to achieve wide market penetration, ranges of at least 500 km at an affordable cost are required. Therefore, significant improvements to lithium-ion batteries (LIBs) in terms of energy density and cost along the battery value chain are required, while other key performance indicators, such as lifetime, safety, fast-charging ability and low-temperature performance, need to be enhanced or at least sustained. Here, we review advances and challenges in LIB materials for automotive applications, in particular with respect to cost and performance parameters. The production processes of anode and cathode materials are discussed, focusing on material abundance and cost. Advantages and challenges of different types of electrolyte for automotive batteries are examined. Finally, energy densities and costs of promising battery chemistries are critically evaluated along with an assessment of the potential to fulfil the ambitious targets of electric vehicle propulsion.

  4. A phenomenological force model of Li-ion battery packs for enhanced performance and health management

    Science.gov (United States)

    Oh, Ki-Yong; Epureanu, Bogdan I.

    2017-10-01

    A 1-D phenomenological force model of a Li-ion battery pack is proposed to enhance the control performance of Li-ion battery cells in pack conditions for efficient performance and health management. The force model accounts for multiple swelling sources under the operational environment of electric vehicles to predict swelling-induced forces in pack conditions, i.e. mechanically constrained. The proposed force model not only incorporates structural nonlinearities due to Li-ion intercalation swelling, but also separates the overall range of states of charge into three ranges to account for phase transitions. Moreover, an approach to study cell-to-cell variations in pack conditions is proposed with serial and parallel combinations of linear and nonlinear stiffness, which account for battery cells and other components in the battery pack. The model is shown not only to accurately estimate the reaction force caused by swelling as a function of the state of charge, battery temperature and environmental temperature, but also to account for cell-to-cell variations due to temperature variations, SOC differences, and local degradation in a wide range of operational conditions of electric vehicles. Considering that the force model of Li-ion battery packs can account for many possible situations in actual operation, the proposed approach and model offer potential utility for the enhancement of current battery management systems and power management strategies.

  5. Influence of Electrode Density on the Performance of Li-Ion Batteries: Experimental and Simulation Results

    Directory of Open Access Journals (Sweden)

    Jelle Smekens

    2016-02-01

    Full Text Available Lithium-ion battery (LIB technology further enabled the information revolution by powering smartphones and tablets, allowing these devices an unprecedented performance against reasonable cost. Currently, this battery technology is on the verge of carrying the revolution in road transport and energy storage of renewable energy. However, to fully succeed in the latter, a number of hurdles still need to be taken. Battery performance and lifetime constitute a bottleneck for electric vehicles as well as stationary electric energy storage systems to penetrate the market. Electrochemical battery models are one of the engineering tools which could be used to enhance their performance. These models can help us optimize the cell design and the battery management system. In this study, we evaluate the ability of the Porous Electrode Theory (PET to predict the effect of changing positive electrode density in the overall performance of Li-ion battery cells. It can be concluded that Porous Electrode Theory (PET is capable of predicting the difference in cell performance due to a changing positive electrode density.

  6. Multiscale modeling and characterization for performance and safety of lithium-ion batteries

    International Nuclear Information System (INIS)

    Pannala, S.; Turner, J. A.; Allu, S.; Elwasif, W. R.; Kalnaus, S.; Simunovic, S.; Kumar, A.; Billings, J. J.; Wang, H.; Nanda, J.

    2015-01-01

    Lithium-ion batteries are highly complex electrochemical systems whose performance and safety are governed by coupled nonlinear electrochemical-electrical-thermal-mechanical processes over a range of spatiotemporal scales. Gaining an understanding of the role of these processes as well as development of predictive capabilities for design of better performing batteries requires synergy between theory, modeling, and simulation, and fundamental experimental work to support the models. This paper presents the overview of the work performed by the authors aligned with both experimental and computational efforts. In this paper, we describe a new, open source computational environment for battery simulations with an initial focus on lithium-ion systems but designed to support a variety of model types and formulations. This system has been used to create a three-dimensional cell and battery pack models that explicitly simulate all the battery components (current collectors, electrodes, and separator). The models are used to predict battery performance under normal operations and to study thermal and mechanical safety aspects under adverse conditions. This paper also provides an overview of the experimental techniques to obtain crucial validation data to benchmark the simulations at various scales for performance as well as abuse. We detail some initial validation using characterization experiments such as infrared and neutron imaging and micro-Raman mapping. In addition, we identify opportunities for future integration of theory, modeling, and experiments

  7. High-performance aqueous rechargeable batteries based on zinc ...

    Indian Academy of Sciences (India)

    A new aqueous Zn–NiCo2O4 rechargeable battery system with a high voltage, consisting of NiCo2O4 as cathode and metal Zn as anode, is proposed for the first time. It is cheap and environmental friendly, and its energy density is about 202.8 Wh kg–1. The system still maintains excellent capacity retention of about 85% ...

  8. Thermal performance of mini-channel liquid cooled cylinder based battery thermal management for cylindrical lithium-ion power battery

    International Nuclear Information System (INIS)

    Zhao, Jiateng; Rao, Zhonghao; Li, Yimin

    2015-01-01

    Highlights: • A new kind of cooling method for cylindrical batteries based on mini-channel liquid cooled cylinder (LCC) is proposed. • The capacity of reducing the T max is limited through increasing the mass flow rate. • The capability of heat dissipation is enhanced first and then weaken along with the rising of entrance size. - Abstract: Battery thermal management is a very active research focus in recent years because of its great essentiality for electric vehicles. In order to maintain the maximum temperature and local temperature difference in appropriate range, a new kind of cooling method for cylindrical batteries which is based on mini-channel liquid cooled cylinder is proposed in this paper. The effects of channel quantity, mass flow rate, flow direction and entrance size on the heat dissipation performance were investigated numerically. The results showed that the maximum temperature can be controlled under 40 °C for 42,110 cylindrical batteries when the number of mini-channel is no less than four and the inlet mass flow rate is 1 × 10 −3 kg/s. Considering both the maximum temperature and local temperature difference, the cooling style by liquid cooled cylinder can demonstrate advantages compared to natural convection cooling only when the channel number is larger than eight. The capability of reducing the maximum temperature is limited through increasing the mass flow rate. The capacity of heat dissipation is enhanced first and then weakened along with the rising of entrance size, when the inlet mass flow rate is constant

  9. Influence of Adhesive System on Performance of SiO/C Lithium-ion Battery

    Directory of Open Access Journals (Sweden)

    Teng Xin

    2015-01-01

    Full Text Available Silicon based anode material is turning into the research hot point of lithium-ion battery material field due to Si inside supporting higher capacity. Furthermore binder applied as major accessory material of anode system could bring anode material & current collector together, thus the influence given by binder system to battery performance becomes the key point. The paper describes the procedure of adopting commercial LiCoO2 SiO/C as composite material & electrolyte, with using styrene butadiene rubber and acrylic acid copolymer as binder to figure out lithium-ion battery with 2.5Ah, which is testified to present better performance on cold temperature & cycle life plus having a little bit swelling compared with the lithium-ion battery using only styrene butadiene rubber as binder.

  10. Design and Performance of Tropical Rainfall Measuring Mission (TRMM) Super NiCd Batteries

    Science.gov (United States)

    Ahmad, Anisa J.; Rao, Gopalakrishna M.; Jallice, Doris E.; Moran Vickie E.

    1999-01-01

    The Tropical Rainfall Measuring Mission (TRMM) is a joint mission between NASA and the National Space Development Agency (NASDA) of Japan. The observatory is designed to monitor and study tropical rainfall and the associated release of energy that helps to power the global atmospheric circulation shaping both weather and climate around the globe. The spacecraft was launched from Japan on November 27,1997 via the NASDA H-2 launch vehicle. The TRMM Power Subsystem is a Peak Power Tracking system that can support the maximum TRMM load of 815 watts at the end of its three year life. The Power Subsystem consists of two 50 Ampere Hour Super NiCd batteries, Gallium Arsenide Solar Array and the Power System Electronics. This paper describes the TRMM Power Subsystem, battery design, cell and battery ground test performance, and in-orbit battery operations and performance.

  11. Experimental investigation on performance of lithium-ion battery thermal management system using flat plate loop heat pipe for electric vehicle application

    International Nuclear Information System (INIS)

    Putra, Nandy; Ariantara, Bambang; Pamungkas, Rangga Aji

    2016-01-01

    Highlights: • Flat plate loop heat pipe (FPLHP) is studied in the thermal management system for electric vehicle. • Distilled water, alcohol, and acetone on thermal performances of FPLHP were tested. • The FPLHP can start up at fairly low heat load. • Temperature overshoot phenomena were observed during the start-up period. - Abstract: The development of electric vehicle batteries has resulted in very high energy density lithium-ion batteries. However, this growth is accompanied by the risk of thermal runaway, which can cause serious accidents. Heat pipes are heat exchangers that are suitable to be applied in electric vehicle battery thermal management for their lightweight and compact size, and they do not require external power supply. This study examined experimentally a flat plate loop heat pipe (FPLHP) performance as a heat exchanger in the thermal management system of the lithium-ion battery for electric vehicle application. The heat generation of the battery was simulated using a cartridge heater. Stainless steel screen mesh was used as the capillary wick. Distilled water, alcohol, and acetone were used as working fluids with a filling ratio of 60%. It was found that acetone gave the best performance that produces a thermal resistance of 0.22 W/°C with 50 °C evaporator temperature at heat flux load of 1.61 W/cm"2.

  12. Rapid restoration of electric vehicle battery performance while driving at cold temperatures

    Science.gov (United States)

    Zhang, Guangsheng; Ge, Shanhai; Yang, Xiao-Guang; Leng, Yongjun; Marple, Dan; Wang, Chao-Yang

    2017-12-01

    Electric vehicles (EVs) driven in cold weather experience two major drawbacks of Li-ion batteries: drastic power loss (up to 10-fold at -30 °C) and restriction of regenerative braking at temperatures below 5-10 °C. Both factors greatly reduce cruise range, exacerbating drivers' range anxiety in winter. While preheating the battery before driving is a practice widely adopted to maintain battery power and EV drivability, it is time-consuming (on the order of 40 min) and prohibits instantaneous mobility. Here we reveal a control strategy that can rapidly restore EV battery power and permit full regeneration while driving at temperatures as low as -40 °C. The strategy involves heating the battery internally during regenerative braking and rest periods of driving. We show that this technique fully restores room-temperature battery power and regeneration in 13, 33, 46, 56 and 112 s into uninterrupted driving in 0, -10, -20, -30 and -40 °C environments, respectively. Correspondingly, the strategy significantly increases cruise range of a vehicle operated at cold temperatures, e.g. 49% at -40 °C in simulated US06 driving cycle tests. The present work suggests that smart batteries with embedded sensing/actuation can leapfrog in performance.

  13. Critical transport issues for improving the performance of aqueous redox flow batteries

    Science.gov (United States)

    Zhou, X. L.; Zhao, T. S.; An, L.; Zeng, Y. K.; Wei, L.

    2017-01-01

    As the fraction of electricity generated from intermittent renewable sources (such as solar and wind) grows, developing reliable energy storage technologies to store electrical energy in large scale is of increasing importance. Redox flow batteries are now enjoying a renaissance and regarded as a leading technology in providing a well-balanced solution for current daunting challenges. In this article, state-of-the-art studies of the complex multicomponent transport phenomena in aqueous redox flow batteries, with a special emphasis on all-vanadium redox flow batteries, are reviewed and summarized. Rather than elaborating on the details of previous experimental and numerical investigations, this article highlights: i) the key transport issues in each battery's component that need to be tackled so that the rate capability and cycling stability of flow batteries can be significantly improved, ii) the basic mechanisms that control the active species/ion/electron transport behaviors in each battery's component, and iii) the key experimental and numerical findings regarding the correlations between the multicomponent transport processes and battery performance.

  14. On Demand Internal Short Circuit Device Enables Verification of Safer, Higher Performing Battery Designs

    Energy Technology Data Exchange (ETDEWEB)

    Darcy, Eric; Keyser, Matthew

    2017-05-15

    The Internal Short Circuit (ISC) device enables critical battery safety verification. With the aluminum interstitial heat sink between the cells, normal trigger cells cannot be driven into thermal runaway without excessive temperature bias of adjacent cells. With an implantable, on-demand ISC device, thermal runaway tests show that the conductive heat sinks protected adjacent cells from propagation. High heat dissipation and structural support of Al heat sinks show high promise for safer, higher performing batteries.

  15. Performance tests of external moderators of a PGNAA setup

    International Nuclear Information System (INIS)

    Naqvi, A.A.; Fazal-ur-Rehman,; Al-Jarallah, M.I.; Abu-Jarad, F.; Maslehuddin, M.

    2003-01-01

    Performance tests of external cylindrical moderators of an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup have been carried out through thermal neutrons and prompt γ-ray yield measurements. The PGNAA setup is to be used for analysis of cement samples. This study was conducted to investigate the effects of geometry of cylindrical moderator on yield of thermal neutrons and prompt γ-rays for two different types of moderator assemblies. One of the moderators was to be used with a small sample and the other to be used with a large sample. Fast and thermal neutron yield was measured inside the sample volume as a function of the front moderator thickness as well as sample length. Neutron yield measurement was carried out at the King Fahd University of Petroleum and Minerals 350 keV pulsed beam accelerator using nuclear track detectors. The pulsed 200 keV deuteron beam with 5 ns pulse width and 31.25 kHz frequency was used to produce 2.8 MeV neutrons via D(d,n) reaction. Neutron yield measurements showed that the large sample moderator has a smaller yield of thermal neutrons as compared to the small sample moderator, which is in complete agreement with the results of Monte Carlo yield calculations of the thermal and fast neutrons from both the moderators. Finally, the prompt γ-ray yield from a Portland cement sample was measured using the two moderators and was compared with each other. As predicted by Monte Carlo simulations, in spite of a smaller yield of thermal neutrons, the large sample moderator has a higher yield of prompt γ-rays

  16. Performance tests of external moderators of a PGNAA setup

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A. E-mail: aanaqvi@kfupm.edu.sa; Fazal-ur-Rehman,; Al-Jarallah, M.I.; Abu-Jarad, F.; Maslehuddin, M

    2003-01-01

    Performance tests of external cylindrical moderators of an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup have been carried out through thermal neutrons and prompt {gamma}-ray yield measurements. The PGNAA setup is to be used for analysis of cement samples. This study was conducted to investigate the effects of geometry of cylindrical moderator on yield of thermal neutrons and prompt {gamma}-rays for two different types of moderator assemblies. One of the moderators was to be used with a small sample and the other to be used with a large sample. Fast and thermal neutron yield was measured inside the sample volume as a function of the front moderator thickness as well as sample length. Neutron yield measurement was carried out at the King Fahd University of Petroleum and Minerals 350 keV pulsed beam accelerator using nuclear track detectors. The pulsed 200 keV deuteron beam with 5 ns pulse width and 31.25 kHz frequency was used to produce 2.8 MeV neutrons via D(d,n) reaction. Neutron yield measurements showed that the large sample moderator has a smaller yield of thermal neutrons as compared to the small sample moderator, which is in complete agreement with the results of Monte Carlo yield calculations of the thermal and fast neutrons from both the moderators. Finally, the prompt {gamma}-ray yield from a Portland cement sample was measured using the two moderators and was compared with each other. As predicted by Monte Carlo simulations, in spite of a smaller yield of thermal neutrons, the large sample moderator has a higher yield of prompt {gamma}-rays.

  17. Effect of rare earth oxide additives on the performance of NiMH batteries

    International Nuclear Information System (INIS)

    Tanaka, Toshiki; Kuzuhara, Minoru; Watada, Masaharu; Oshitani, Masahiko

    2006-01-01

    To date, we have performed research on nickel-metal hydride (NiMH) batteries used in many applications and have found that addition of rare earth oxides to the nickel electrode and the hydrogen-storage alloy (MH) electrode improves battery performance significantly. Because heavy rare earth oxides of such as Er, Tm, Yb and Lu have remarkable properties that shift the oxygen evolution overpotentials of nickel electrodes to more noble potentials, it is possible to improve high-temperature charge efficiency of nickel-metal hydride secondary batteries by adding them to nickel electrodes. Furthermore, addition of heavy rare earth oxides to MH electrodes depresses an acceleration of the alloy corrosion and improves service life of the battery at high temperatures. Accordingly, addition of heavy rare earth oxides is effective for NiMH batteries used in high-temperature applications such as electric vehicles (EVs), hybrid vehicles (HEVs) and rapid charge devices. In this study, we discussed how the addition of heavy rare earth oxides affects NiMH battery characteristics

  18. Improved electrochemical performances of CuO nanotube array prepared via electrodeposition as anode for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2015-10-15

    Graphical abstract: CuO nanotube array electrodes prepared by electrodeposition method exhibit an excellent lithium ion storage ability as anode of Li-ion battery. - Highlights: • CuO nanotube arrays are synthesized by an electrodeposition method. • CuO nanotube shows a high-rate performance. • CuO nanotube shows an excellent cycling performance. - Abstract: We report a facile strategy to prepared CuO nanotube arrays directly grown on Cu plate through the electrodeposition method. The as-prepared CuO nanotubes show a quasi-cylinder nanostructure with internal diameters of ca. ∼100 nm, external diameters of ca. ∼120 nm, and average length of ∼3 μm. As an anode for lithium ion batteries, the electrochemical properties of the CuO nanotube arrays are investigated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests. Due to the unique nanotube nanostructure, the as-prepared CuO electrodes exhibit good rate performance (550 mAh g{sup −1} at 0.1 C and 464 mAh g{sup −1} at 1 C) and cycling performance (581 mAh g{sup −1} at 0.1 C and 538 mAh g{sup −1} at 0.5 C)

  19. The effects of high frequency current ripple on electric vehicle battery performance

    International Nuclear Information System (INIS)

    Uddin, Kotub; Moore, Andrew D.; Barai, Anup; Marco, James

    2016-01-01

    Highlights: • Experimental study into the impact of current ripple on li-ion battery degradation. • 15 cells exercised with 1200 cycles coupled AC–DC signals, at 5 frequencies. • Results highlight a greater spread of degradation for cells exposed to AC excitation. • Implications for BMS control, thermal management and system integration. - Abstract: The power electronic subsystems within electric vehicle (EV) powertrains are required to manage both the energy flows within the vehicle and the delivery of torque by the electrical machine. Such systems are known to generate undesired electrical noise on the high voltage bus. High frequency current oscillations, or ripple, if unhindered will enter the vehicle’s battery system. Real-world measurements of the current on the high voltage bus of a series hybrid electric vehicle (HEV) show that significant current perturbations ranging from 10 Hz to in excess of 10 kHz are present. Little is reported within the academic literature about the potential impact on battery system performance and the rate of degradation associated with exposing the battery to coupled direct current (DC) and alternating currents (AC). This paper documents an experimental investigation that studies the long-term impact of current ripple on battery performance degradation. Initial results highlight that both capacity fade and impedance rise progressively increase as the frequency of the superimposed AC current increases. A further conclusion is that the spread of degradation for cells cycled with a coupled AC–DC signal is considerably more than for cells exercised with a traditional DC waveform. The underlying causality for this degradation is not yet understood. However, this has important implications for the battery management system (BMS). Increased variations in cell capacity and impedance will cause differential current flows and heat generation within the battery pack that if not properly managed will further reduce battery life

  20. Generalized Characterization Methodology for Performance Modelling of Lithium-Ion Batteries

    DEFF Research Database (Denmark)

    Stroe, Daniel Loan; Swierczynski, Maciej Jozef; Stroe, Ana-Irina

    2016-01-01

    Lithium-ion (Li-ion) batteries are complex energy storage devices with their performance behavior highly dependent on the operating conditions (i.e., temperature, load current, and state-of-charge (SOC)). Thus, in order to evaluate their techno-economic viability for a certain application, detailed...... information about Li-ion battery performance behavior becomes necessary. This paper proposes a comprehensive seven-step methodology for laboratory characterization of Li-ion batteries, in which the battery’s performance parameters (i.e., capacity, open-circuit voltage (OCV), and impedance) are determined...... and their dependence on the operating conditions are obtained. Furthermore, this paper proposes a novel hybrid procedure for parameterizing the batteries’ equivalent electrical circuit (EEC), which is used to emulate the batteries’ dynamic behavior. Based on this novel parameterization procedure, the performance model...

  1. Simulation and experimental study on lithium ion battery short circuit

    International Nuclear Information System (INIS)

    Zhao, Rui; Liu, Jie; Gu, Junjie

    2016-01-01

    Highlights: • Both external and internal short circuit tests were performed on Li-ion batteries. • An electrochemical–thermal model with an additional nail site heat source is presented. • The model can accurately simulate the temperature variations of non-venting batteries. • The model is reliable in predicting the occurrence and start time of thermal runaway. • A hydrogel cooling system proves its strength in preventing battery thermal runaway. - Abstract: Safety is the first priority in lithium ion (Li-ion) battery applications. A large portion of electrical and thermal hazards caused by Li-ion battery is associated with short circuit. In this paper, both external and internal short circuit tests are conducted. Li-ion batteries and battery packs of different capacities are used. The results indicate that external short circuit is worse for smaller size batteries due to their higher internal resistances, and this type of short can be well managed by assembling fuses. In internal short circuit tests, higher chance of failure is found on larger capacity batteries. A modified electrochemical–thermal model is proposed, which incorporates an additional heat source from nail site and proves to be successful in depicting temperature changes in batteries. Specifically, the model is able to estimate the occurrence and approximate start time of thermal runaway. Furthermore, the effectiveness of a hydrogel based thermal management system in suppressing thermal abuse and preventing thermal runaway propagation is verified through the external and internal short tests on batteries and battery packs.

  2. Does External Knowledge Sourcing Enhance Market Performance? Evidence from the Korean Manufacturing Industry.

    Science.gov (United States)

    Lee, Kibaek; Yoo, Jaeheung; Choi, Munkee; Zo, Hangjung; Ciganek, Andrew P

    2016-01-01

    Firms continuously search for external knowledge that can contribute to product innovation, which may ultimately increase market performance. The relationship between external knowledge sourcing and market performance is not well-documented. The extant literature primarily examines the causal relationship between external knowledge sources and product innovation performance or to identify factors which moderates the relationship between external knowledge sourcing and product innovation. Non-technological innovations, such as organization and marketing innovations, intervene in the process of external knowledge sourcing to product innovation to market performance but has not been extensively examined. This study addresses two research questions: does external knowledge sourcing lead to market performance and how does external knowledge sourcing interact with a firm's different innovation activities to enhance market performance. This study proposes a comprehensive model to capture the causal mechanism from external knowledge sourcing to market performance. The research model was tested using survey data from manufacturing firms in South Korea and the results demonstrate a strong statistical relationship in the path of external knowledge sourcing (EKS) to product innovation performance (PIP) to market performance (MP). Organizational innovation is an antecedent to EKS while marketing innovation is a consequence of EKS, which significantly influences PIP and MP. The results imply that any potential EKS effort should also consider organizational innovations which may ultimately enhance market performance. Theoretical and practical implications are discussed as well as concluding remarks.

  3. Does External Knowledge Sourcing Enhance Market Performance? Evidence from the Korean Manufacturing Industry

    Science.gov (United States)

    Lee, Kibaek; Yoo, Jaeheung; Choi, Munkee; Zo, Hangjung; Ciganek, Andrew P.

    2016-01-01

    Firms continuously search for external knowledge that can contribute to product innovation, which may ultimately increase market performance. The relationship between external knowledge sourcing and market performance is not well-documented. The extant literature primarily examines the causal relationship between external knowledge sources and product innovation performance or to identify factors which moderates the relationship between external knowledge sourcing and product innovation. Non-technological innovations, such as organization and marketing innovations, intervene in the process of external knowledge sourcing to product innovation to market performance but has not been extensively examined. This study addresses two research questions: does external knowledge sourcing lead to market performance and how does external knowledge sourcing interact with a firm’s different innovation activities to enhance market performance. This study proposes a comprehensive model to capture the causal mechanism from external knowledge sourcing to market performance. The research model was tested using survey data from manufacturing firms in South Korea and the results demonstrate a strong statistical relationship in the path of external knowledge sourcing (EKS) to product innovation performance (PIP) to market performance (MP). Organizational innovation is an antecedent to EKS while marketing innovation is a consequence of EKS, which significantly influences PIP and MP. The results imply that any potential EKS effort should also consider organizational innovations which may ultimately enhance market performance. Theoretical and practical implications are discussed as well as concluding remarks. PMID:28006022

  4. Improving lithium-ion battery performances by adding fly ash from coal combustion on cathode film

    Energy Technology Data Exchange (ETDEWEB)

    Dyartanti, Endah Retno; Jumari, Arif, E-mail: arifjumari@yahoo.com; Nur, Adrian; Purwanto, Agus [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    A lithium battery is composed of anode, cathode and a separator. The performance of lithium battery is also influenced by the conductive material of cathode film. In this research, the use of fly ash from coal combustion as conductive enhancer for increasing the performances of lithium battery was investigated. Lithium iron phosphate (LiFePO{sub 4}) was used as the active material of cathode. The dry fly ash passed through 200 mesh screen, LiFePO{sub 4} and acethylene black (AB), polyvinylidene fluoride (PVDF) as a binder and N-methyl-2-pyrrolidone (NMP) as a solvent were mixed to form slurry. The slurry was then coated, dried and hot pressed to obtain the cathode film. The ratio of fly ash and AB were varied at the values of 1%, 2%, 3%, 4% and 5% while the other components were at constant. The anode film was casted with certain thickness and composition. The performance of battery lithium was examined by Eight Channel Battery Analyzer, the composition of the cathode film was examined by XRD (X-Ray Diffraction), and the structure and morphology of the anode film was analyzed by SEM (Scanning Electron Microscope). The composition, structure and morphology of cathode film was only different when fly ash added was 4% of AB or more. The addition of 2% of AB on cathode film gave the best performance of 81.712 mAh/g on charging and 79.412 mAh/g on discharging.

  5. Improving cylinder-type LiFePO4 battery performance via control of internal resistance

    Science.gov (United States)

    Purwanto, Agus; Jumari, Arif; Nizam, Muhammad; Widiyandari, Hendri; Sudaryanto; Deswita; Azmin Mohamad, Ahmad

    2018-04-01

    Strategies for controlling the internal resistance to improve battery performance were systematically investigated. Electrode densification of LiFePO4 cathodes significantly reduced the internal resistance of the prepared batteries. Densification by reduction to 31.25% of initial thickness resulted in optimal electrochemical performance of the prepared LiFePO4 batteries. The addition of KS 6 graphite material improved the conductivity of the cathodes, which was indicated by a lowering of the internal resistance. The internal resistance was decreased from 73 to 54 when the KS6/AB ratio was varied from 3 to 1. Another factor in controlling the internal resistance was the location of a welded aluminum tab in the cathode. The welding of an aluminum tab in a small gap in the cathode significantly reduced the internal resistance. Thus, three main factors can be performed during fabrication to reduce the internal resistance of a LiFePO4 battery: cathode densification, KS-6 graphite addition, and the arrangement of an aluminum tab welded to the cathode. By optimizing these factors, high-performance LFP batteries were produced.

  6. Improved Performance and Safety for High Energy Batteries Through Use of Hazard Anticipation and Capacity Prediction

    Science.gov (United States)

    Atwater, Terrill

    1993-01-01

    Prediction of the capacity remaining in used high rate, high energy batteries is important information to the user. Knowledge of the capacity remaining in used batteries results in better utilization. This translates into improved readiness and cost savings due to complete, efficient use. High rate batteries, due to their chemical nature, are highly sensitive to misuse (i.e., over discharge or very high rate discharge). Battery failure due to misuse or manufacturing defects could be disastrous. Since high rate, high energy batteries are expensive and energetic, a reliable method of predicting both failures and remaining energy has been actively sought. Due to concerns over safety, the behavior of lithium/sulphur dioxide cells at different temperatures and current drains was examined. The main thrust of this effort was to determine failure conditions for incorporation in hazard anticipation circuitry. In addition, capacity prediction formulas have been developed from test data. A process that performs continuous, real-time hazard anticipation and capacity prediction was developed. The introduction of this process into microchip technology will enable the production of reliable, safe, and efficient high energy batteries.

  7. Assessing Discriminative Performance at External Validation of Clinical Prediction Models.

    Directory of Open Access Journals (Sweden)

    Daan Nieboer

    Full Text Available External validation studies are essential to study the generalizability of prediction models. Recently a permutation test, focusing on discrimination as quantified by the c-statistic, was proposed to judge whether a prediction model is transportable to a new setting. We aimed to evaluate this test and compare it to previously proposed procedures to judge any changes in c-statistic from development to external validation setting.We compared the use of the permutation test to the use of benchmark values of the c-statistic following from a previously proposed framework to judge transportability of a prediction model. In a simulation study we developed a prediction model with logistic regression on a development set and validated them in the validation set. We concentrated on two scenarios: 1 the case-mix was more heterogeneous and predictor effects were weaker in the validation set compared to the development set, and 2 the case-mix was less heterogeneous in the validation set and predictor effects were identical in the validation and development set. Furthermore we illustrated the methods in a case study using 15 datasets of patients suffering from traumatic brain injury.The permutation test indicated that the validation and development set were homogenous in scenario 1 (in almost all simulated samples and heterogeneous in scenario 2 (in 17%-39% of simulated samples. Previously proposed benchmark values of the c-statistic and the standard deviation of the linear predictors correctly pointed at the more heterogeneous case-mix in scenario 1 and the less heterogeneous case-mix in scenario 2.The recently proposed permutation test may provide misleading results when externally validating prediction models in the presence of case-mix differences between the development and validation population. To correctly interpret the c-statistic found at external validation it is crucial to disentangle case-mix differences from incorrect regression coefficients.

  8. Potential use of battery packs from NCAP tested vehicles.

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, Joshua; Orendorff, Christopher J.

    2013-10-01

    Several large electric vehicle batteries available to the National Highway Traffic Safety Administration are candidates for use in future safety testing programs. The batteries, from vehicles subjected to NCAP crashworthiness testing, are considered potentially damaged due to the nature of testing their associated vehicles have been subjected to. Criteria for safe shipping to Sandia is discussed, as well as condition the batteries must be in to perform testing work. Also discussed are potential tests that could be performed under a variety of conditions. The ultimate value of potential testing performed on these cells will rest on the level of access available to the battery pack, i.e. external access only, access to the on board monitoring system/CAN port or internal electrical access to the battery. Greater access to the battery than external visual and temperature monitoring would likely require input from the battery manufacturer.

  9. Factors Affecting the Battery Performance of Anthraquinone-based Organic Cathode Materials

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Wu; Read, Adam L.; Koech, Phillip K.; Hu, Dehong; Wang, Chong M.; Xiao, Jie; Padmaperuma, Asanga B.; Graff, Gordon L.; Liu, Jun; Zhang, Jiguang

    2012-02-01

    Two organic cathode materials based on poly(anthraquinonyl sulfide) structure with different substitution positions were synthesized and their electrochemical behavior and battery performances were investigated. The substitution positions on the anthraquinone structure, binders for electrode preparation and electrolyte formulations have been found to have significant effects on the battery performances of such organic cathode materials. The substitution position with less steric stress has higher capacity, longer cycle life and better high-rate capability. Polyvinylidene fluoride binder and ether-based electrolytes are favorable for the high capacity and long cycle life of the quinonyl organic cathodes.

  10. H2-O2 fuel cell and advanced battery power systems for autonomous underwater vehicles: performance envelope comparisons

    International Nuclear Information System (INIS)

    Schubak, G.E.; Scott, D.S.

    1993-01-01

    Autonomous underwater vehicles have traditionally been powered by low energy density lead-acid batteries. Recently, advanced battery technologies and H 2 -O 2 fuel cells have become available, offering significant improvements in performance. This paper compares the solid polymer fuel cell to the lithium-thionyl chloride primary battery, sodium-sulfur battery, and lead acid battery for a variety of missions. The power system performance is simulated using computer modelling techniques. Performance envelopes are constructed, indicating domains of preference for competing power system technologies. For most mission scenarios, the solid polymer fuel cell using liquid reactant storage is the preferred system. Nevertheless, the advanced battery systems are competitive with the fuel cell systems using gaseous hydrogen storage, and they illustrate preferred performance for missions requiring high power density. 11 figs., 4 tabs., 15 refs

  11. Electrochemical performance and safety features of high-safety lithium ion battery using novel branched additive for internal short protection

    International Nuclear Information System (INIS)

    Li Yuhan; Lee, Meng-Lun; Wang Fuming; Yang, Chang-Rung; Chu, Peter P.J.; Yau, Shueh-Lin; Pan, Jing-Pin

    2012-01-01

    Highlights: ► N-phenylmaleimide-containing branched oligomer has been employed as an additive in lithium cells. ► The branched oligomer additive enhances safety and cycling performance of Li ion battery. ► The highest temperature of branched oligomer-containing battery was only 85 °C in the nail penetration test. - Abstract: In this study, we have investigated N-phenylmaleimide/bismaleimide-containing branched oligomer (BO1) as additive in Li-ion batteries to increase the safety performance by reducing the probability of batteries suffering an internal short circuit. In the nail penetration test, a LiCoO 2 /MCMB full battery with N-phenylmaleimide/bismaleimide-containing branched oligomer (BO1) showed a significant improvement in thermal stability and was able to restrain the temperature of the battery at about 85 °C. Furthermore, we found that N-phenylmaleimide/bismaleimide-containing branched oligomer (BO1) contained battery revealed better cycling and electrochemical performance, compared with the battery with bismaleimide-containing branched oligomer (BO3) in the electrolyte. The improvement might result from the favorable ionic conductivity, Li ion mobility and lower resistance in the battery. This additive can meet the cycling performance and safety requirements for Li-ion batteries.

  12. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    International Nuclear Information System (INIS)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin

    2014-01-01

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles

  13. Highly featured amorphous silicon nanorod arrays for high-performance lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani-Amiri, Samaneh; Safiabadi Tali, Seied Ali; Azimi, Soheil; Sanaee, Zeinab; Mohajerzadeh, Shamsoddin, E-mail: mohajer@ut.ac.ir [Thin Film and Nanoelectronics Lab, Nanoelectronics Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran 143957131 (Iran, Islamic Republic of)

    2014-11-10

    High aspect-ratio vertical structures of amorphous silicon have been realized using hydrogen-assisted low-density plasma reactive ion etching. Amorphous silicon layers with the thicknesses ranging from 0.5 to 10 μm were deposited using radio frequency plasma enhanced chemical vapor deposition technique. Standard photolithography and nanosphere colloidal lithography were employed to realize ultra-small features of the amorphous silicon. The performance of the patterned amorphous silicon structures as a lithium-ion battery electrode was investigated using galvanostatic charge-discharge tests. The patterned structures showed a superior Li-ion battery performance compared to planar amorphous silicon. Such structures are suitable for high current Li-ion battery applications such as electric vehicles.

  14. Ex-situ and in-situ observations of the effects of gamma radiation on lithium ion battery performance

    Science.gov (United States)

    Tan, Chuting; Bashian, Nicholas H.; Hemmelgarn, Chase W.; Thio, Wesley J.; Lyons, Daniel J.; Zheng, Yuan F.; Cao, Lei R.; Co, Anne C.

    2017-07-01

    Radiation effects induced by gamma rays on battery performance were investigated by measuring the capacity and resistance of a series of battery coin cells in-situ directly under gamma radiation and ex-situ. An experimental setup was developed to charge and discharge batteries directly under gamma radiation, equipped with precise temperature control, at The Ohio State University Nuclear Reactor Lab. Latent effects induced by gamma radiation on battery components directly influence their performance. Charge and discharge capacity and overall resistance throughout a time span of several weeks post irradiation were monitored and compared to control groups. It was found that exposure to gamma radiation does not significantly alter the available capacity and the overall cell resistance immediately, however, battery performance significantly decreases with time post irradiation. Also, batteries exposed to a higher cumulative dose showed close-to-zero capacity at two-week post irradiation.

  15. Optimal distance of an external focus of attention in standing long jump performance of athletes

    Directory of Open Access Journals (Sweden)

    Gh. Lotfi

    2018-06-01

    Full Text Available Background and Study Aim: Recently, studies have shown that an external focus of attention improves the performance of individuals. Some studies have also confirmed the superiority of distances away from body for external focus of attention. The aim of this study was to determine the optimal distance of an external focus of attention when performing athletes' standing long jump. Material and Method: 51 volunteer students (M age= 23.31 ± 5.26 years were selected as sample. At first all they performed a standing long jump in control status (without instruction for focus of attention. Then in an interpersonal counterbalanced design, a pair of jumps was performed with four different distances of an external focus of attention. These distances included 0.5, 2.5, 4 and 8 meters from the jump start line marked with colored tapes on the ground. Results: The results showed that having an external focus of attention compare to the control conditions has a significant advantage in the performance of the athlete's standing long jump. Also, the performance of athletes at different distances of an external focus of attention was compared. Results showed that the four-meter distance was significantly better performance than the half-meter distance of an external focus of attention. Conclusion: Four-meter distance can be introduced as the optimal distance of an external focus of attention in the performance of athletes’ standing long jump.

  16. Enhancement of electromechanical manipulator performance by external sensory feedback

    International Nuclear Information System (INIS)

    Um, Taejun; Yoon, Jisup; Jung, Wootae; Lee, Jaesol.

    1990-01-01

    The electromechanical manipulator (EMM) is widely used in nuclear facilities because of its strength and mechanical reliability. Nevertheless, the lack of internal position or force feedback makes it unsuitable for many tasks that require a high level of dexterity. At the remote handling department of Korea Atomic Energy Research Institute, a series of research and development (R and D) activities was conducted to provide a higher degree of intelligence to the EMM with the aid of external sensory devices. These R and D activities focus on remote viewing and remote measurement in radioactive environments. As a result, an improved EMM system was achieved that incorporates various sensory devices such as a motion tracking system and a laser vision system. This paper presents detailed technical descriptions of these sensors and test results

  17. Study of nickel hydrogen battery discharge performance after charge and stand at warm temperature

    International Nuclear Information System (INIS)

    Donley, S.W.; Verrier, D.C.

    1992-01-01

    Spacecraft batteries are normally installed in the discharged condition. It may be necessary that they be charged and trickle-charged prior to launch in an environment different from that in which they are intended to operate. The purpose of the testing described in this paper was to determine the battery capacity achieved after treatment at prelaunch conditions as a function of charge rate, charge temperature, trickle charge temperature, and time. In this testing the discharge in every case was performed under simulated space thermal conditions

  18. Performance enhancement of spherical natural graphite by phenol resin in lithium ion batteries

    International Nuclear Information System (INIS)

    Wu, Y.-S.; Wang, Y.-H.; Lee, Y.-H.

    2006-01-01

    The capacity of natural graphite in the lithium ion battery anode decays seriously. The phenol resin is used as a reaction material to modify the electrochemical performance of spherical graphite as the anode material in lithium ion batteries. Measuring the reversible capacity indicates change in the surface structure of spherical graphite. A dense layer of methyl groups was thus formed. Some structural imperfections are removed and the stability of the graphite structure is increased. Clearly, reducing the irreversible capacity is beneficial in controlling the uniformity of the spherical graphite surface structure

  19. Design and Performance of Energy Conversion Units of Betavoltaic Isotopic Batteries

    International Nuclear Information System (INIS)

    Wang Guanquan; Yang Yuqing; Zhang Huaming; Hu Rui; Wei Hongyuan; Xiong Xiaoling; Luo Shunzhong

    2010-01-01

    Based on the single crystal silicon semiconductor junction devices, the relationships between their configurable parameters and the electrical properties were discussed for the purpose of design of energy conversion units of betavoltaic isotopic batteries. Two kinds of silicon semiconductor junction devices as energy conversion units of betavoltaic batteries were designed and customized. The electrical output properties of the devices irradiated by 63 Ni source were measured. The results show that the new designed devices perform better than the existing commercial one in open-circuit voltage, output power and energy conversion efficiency. (authors)

  20. A high performance hybrid battery based on aluminum anode and LiFePO4 cathode.

    Science.gov (United States)

    Sun, Xiao-Guang; Bi, Zhonghe; Liu, Hansan; Fang, Youxing; Bridges, Craig A; Paranthaman, M Parans; Dai, Sheng; Brown, Gilbert M

    2016-01-28

    A novel hybrid battery utilizing an aluminum anode, a LiFePO4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl3) (EMImCl-AlCl3, 1-1.1 in molar ratio) with or without LiAlCl4 is proposed. The hybrid ion battery delivers an initial high capacity of 160 mA h g(-1) at a current rate of C/5. It also shows good rate capability and cycling performance.

  1. The Comparative Performance of Batteries: The Lead-Acid and the Aluminum-Air Cells.

    Science.gov (United States)

    LeRoux, Xavier; And Others

    1996-01-01

    Describes a teaching program that shows how electrochemical principles can be conveyed by means of hands-on experiences of student-centered teaching experiments. Employs the readily available lead-acid cell and the simple aluminum-air cell. Discusses the batteries, equilibrium cell potential, performance comparison, current, electrode separation,…

  2. Performance of a Battery Electric Vehicle in the Cold Climate and Hilly Terrain of Vermont

    Science.gov (United States)

    2008-12-23

    The goal of this research project was to determine the performance of a battery electric vehicle (BEV) in the cold climate and hilly terrain of Vermont. For this study, a 2005 Toyota Echo was converted from an internal combustion engine (ICE) vehicle...

  3. Investigation of Battery Heat Generation and Key Performance Indicator Efficiency Using Isothermal Calorimeter

    DEFF Research Database (Denmark)

    Khan, Mohammad Rezwan; Kær, Søren Knudsen

    2016-01-01

    In this experiment-based research, the performance and behaviour of a pouch type Li-ion battery cell are reported. The commercial test cell has a Lithium Titanate Oxide (LTO) based anode with 13Ah capacity. It is accomplished by measuring the evolution of surface temperature distribution, and the...

  4. Energy performance analysis for a photovoltaic, diesel, battery hybrid power supply system

    CSIR Research Space (South Africa)

    Tazvinga, Henerica

    2010-03-01

    Full Text Available This paper looks at an energy performance analysis for a photovoltaic, diesel, and battery hybrid power supply system. The procedure starts by the identification of the hourly load requirements for a typical target consumer and the concept of load...

  5. Dynamic performance improvement of standalone battery integrated PMSG wind energy system using proportional resonant controller

    Directory of Open Access Journals (Sweden)

    Dileep Kumar Varma Sagiraju

    2017-08-01

    Full Text Available The load voltage and frequency should be controlled under steady state and transient conditions in off grid applications. Power quality and power management is very important task for rural communities under erratic wind and load conditions. This paper presents a coordinated Proportional resonant (PR and battery energy controller for enhancement of power quality and power management in direct drive standalone wind energy system. The dynamic performance of standalone direct drive Permanent Magnet Synchronous Generator (PMSG is investigated with the proposed control scheme under various operating conditions such as fluctuating wind with step increase and decrease in wind velocity, balanced and unbalanced load conditions. The proposed PR control strategy with battery energy controller also ensures effective power balance between wind and battery source in order to fulfill the load demand. The superiority of the proposed control strategy is confirmed by comparing with the traditional vector control strategy under fluctuating wind and load conditions through MATLAB/SIMULINK platform.

  6. Modular Approach for Continuous Cell-Level Balancing to Improve Performance of Large Battery Packs: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muneed ur Rehman, M.; Evzelman, M.; Hathaway, K.; Zane, R.; Plett, G. L.; Smith, K.; Wood, E.; Maksimovic, D.

    2014-10-01

    Energy storage systems require battery cell balancing circuits to avoid divergence of cell state of charge (SOC). A modular approach based on distributed continuous cell-level control is presented that extends the balancing function to higher level pack performance objectives such as improving power capability and increasing pack lifetime. This is achieved by adding DC-DC converters in parallel with cells and using state estimation and control to autonomously bias individual cell SOC and SOC range, forcing healthier cells to be cycled deeper than weaker cells. The result is a pack with improved degradation characteristics and extended lifetime. The modular architecture and control concepts are developed and hardware results are demonstrated for a 91.2-Wh battery pack consisting of four series Li-ion battery cells and four dual active bridge (DAB) bypass DC-DC converters.

  7. A Theoretical Analysis of the Performance of Learning Disabled Students on the Woodcock-Johnson Psycho-Educational Battery.

    Science.gov (United States)

    Shinn, Mark; And Others

    Two studies were conducted to (1) analyze the subtest characteristics of the Woodcock-Johnson Psycho-Educational Battery, and (2) apply those results to an analysis of 50 fourth grade learning disabled (LD) students' performance on the Battery. Analyses indicated that the poorer performance of LD students on the Woodcock-Johnson Tests of Cognitive…

  8. Performance and safety to NAVSEA instruction 9310.1A of lithium-thionyl chloride reserve batteries

    Science.gov (United States)

    Hall, J. C.

    1984-09-01

    The design, performance and safety of a fully engineered, selfcontained Li/SOCl2 battery as the power source for underwater applications. In addition to meeting the performance standards of the end user this battery is successfully tested under the rigorous safety conditions of NAVSEA Instruction 9310.1A for use on land, aircraft and surface ships.

  9. Hierarchical Porous Carbon Spheres for High-Performance Na-O2 Batteries.

    Science.gov (United States)

    Sun, Bing; Kretschmer, Katja; Xie, Xiuqiang; Munroe, Paul; Peng, Zhangquan; Wang, Guoxiu

    2017-12-01

    As a new family member of room-temperature aprotic metal-O 2 batteries, Na-O 2 batteries, are attracting growing attention because of their relatively high theoretical specific energy and particularly their uncompromised round-trip efficiency. Here, a hierarchical porous carbon sphere (PCS) electrode that has outstanding properties to realize Na-O 2 batteries with excellent electrochemical performances is reported. The controlled porosity of the PCS electrode, with macropores formed between PCSs and nanopores inside each PCS, enables effective formation/decomposition of NaO 2 by facilitating the electrolyte impregnation and oxygen diffusion to the inner part of the oxygen electrode. In addition, the discharge product of NaO 2 is deposited on the surface of individual PCSs with an unusual conformal film-like morphology, which can be more easily decomposed than the commonly observed microsized NaO 2 cubes in Na-O 2 batteries. A combination of coulometry, X-ray diffraction, and in situ differential electrochemical mass spectrometry provides compelling evidence that the operation of the PCS-based Na-O 2 battery is underpinned by the formation and decomposition of NaO 2 . This work demonstrates that employing nanostructured carbon materials to control the porosity, pore-size distribution of the oxygen electrodes, and the morphology of the discharged NaO 2 is a promising strategy to develop high-performance Na-O 2 batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. [Research and Design of a System for Detecting Automated External Defbrillator Performance Parameters].

    Science.gov (United States)

    Wang, Kewu; Xiao, Shengxiang; Jiang, Lina; Hu, Jingkai

    2017-09-30

    In order to regularly detect the performance parameters of automated external defibrillator (AED), to make sure it is safe before using the instrument, research and design of a system for detecting automated external defibrillator performance parameters. According to the research of the characteristics of its performance parameters, combing the STM32's stability and high speed with PWM modulation control, the system produces a variety of ECG normal and abnormal signals through the digital sampling methods. Completed the design of the hardware and software, formed a prototype. This system can accurate detect automated external defibrillator discharge energy, synchronous defibrillation time, charging time and other key performance parameters.

  11. The bidirectional pathways between internalizing and externalizing problems and academic performance from 6 to 18 years.

    Science.gov (United States)

    Van der Ende, Jan; Verhulst, Frank C; Tiemeier, Henning

    2016-08-01

    Internalizing and externalizing problems are associated with poor academic performance, both concurrently and longitudinally. Important questions are whether problems precede academic performance or vice versa, whether both internalizing and externalizing are associated with academic problems when simultaneously tested, and whether associations and their direction depend on the informant providing information. These questions were addressed in a sample of 816 children who were assessed four times. The children were 6-10 years at baseline and 14-18 years at the last assessment. Parent-reported internalizing and externalizing problems and teacher-reported academic performance were tested in cross-lagged models to examine bidirectional paths between these constructs. These models were compared with cross-lagged models testing paths between teacher-reported internalizing and externalizing problems and parent-reported academic performance. Both final models revealed similar pathways from mostly externalizing problems to academic performance. No paths emerged from internalizing problems to academic performance. Moreover, paths from academic performance to internalizing and externalizing problems were only found when teachers reported on children's problems and not for parent-reported problems. Additional model tests revealed that paths were observed in both childhood and adolescence. Externalizing problems place children at increased risk of poor academic performance and should therefore be the target for interventions.

  12. Dual-Functional Graphene Carbon as Polysulfide Trapper for High-Performance Lithium Sulfur Batteries.

    Science.gov (United States)

    Zhang, Linlin; Wan, Fang; Wang, Xinyu; Cao, Hongmei; Dai, Xi; Niu, Zhiqiang; Wang, Yijing; Chen, Jun

    2018-02-14

    The lithium sulfur (Li-S) battery has attracted much attention due to its high theoretical capacity and energy density. However, its cycling stability and rate performance urgently need to improve because of its shuttle effect. Herein, oxygen-doped carbon on the surface of reduced graphene oxide (labeled as ODC/rGO) was fabricated to modify the separators of Li-S batteries to limit the dissolution of the lithium polysulfides. The mesoporous structure in ODC/rGO can not only serve as the physical trapper, but also provide abundant channels for fast ion transfer, which is beneficial for effective confinement of the dissoluble intermediates and superior rate performance. Moreover, the oxygen-containing groups in ODC/rGO are able to act as chemical adsorption sites to immobilize the lithium polysulfides, suppressing their dissolution in electrolyte to enhance the utilization of sulfur cathode in Li-S batteries. As a result, because of the synergetic effects of physical adsorption and chemical interaction to immobilize the soluble polysulfides, the Li-S batteries with the ODC/rGO-coated separator exhibit excellent rate performance and good long-term cycling stability with 0.057% capacity decay per cycle at 1.0 C after 600 cycles.

  13. Electrochemical performance studies of MnO2 nanoflowers recovered from spent battery

    International Nuclear Information System (INIS)

    Ali, Gomaa A.M.; Tan, Ling Ling; Jose, Rajan; Yusoff, Mashitah M.; Chong, Kwok Feng

    2014-01-01

    Highlights: • MnO 2 is recovered from spent zinc–carbon batteries as nanoflowers structure. • Recovered MnO 2 nanoflowers show high specific capacitance. • Recovered MnO 2 nanoflowers show stable electrochemical cycling up to 900 cycles. • Recovered MnO 2 nanoflowers show low resistance in EIS data. - Abstract: The electrochemical performance of MnO 2 nanoflowers recovered from spent household zinc–carbon battery is studied by cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy. MnO 2 nanoflowers are recovered from spent zinc–carbon battery by combination of solution leaching and electrowinning techniques. In an effort to utilize recovered MnO 2 nanoflowers as energy storage supercapacitor, it is crucial to understand their structure and electrochemical performance. X-ray diffraction analysis confirms the recovery of MnO 2 in birnessite phase, while electron microscopy analysis shows the MnO 2 is recovered as 3D nanostructure with nanoflower morphology. The recovered MnO 2 nanoflowers exhibit high specific capacitance (294 F g −1 at 10 mV s −1 ; 208.5 F g −1 at 0.1 A g −1 ) in 1 M Na 2 SO 4 electrolyte, with stable electrochemical cycling. Electrochemical data analysis reveal the great potential of MnO 2 nanoflowers recovered from spent zinc–carbon battery in the development of high performance energy storage supercapacitor system

  14. Improving the Performance of Lithium–Sulfur Batteries by Conductive Polymer Coating

    KAUST Repository

    Yang, Yuan

    2011-11-22

    Rechargeable lithium-sulfur (Li-S) batteries hold great potential for next-generation high-performance energy storage systems because of their high theoretical specific energy, low materials cost, and environmental safety. One of the major obstacles for its commercialization is the rapid capacity fading due to polysulfide dissolution and uncontrolled redeposition. Various porous carbon structures have been used to improve the performance of Li-S batteries, as polysulfides could be trapped inside the carbon matrix. However, polysulfides still diffuse out for a prolonged time if there is no effective capping layer surrounding the carbon/sulfur particles. Here we explore the application of conducting polymer to minimize the diffusion of polysulfides out of the mesoporous carbon matrix by coating poly(3,4-ethylenedioxythiophene)- poly(styrene sulfonate) (PEDOT:PSS) onto mesoporous carbon/sulfur particles. After surface coating, coulomb efficiency of the sulfur electrode was improved from 93% to 97%, and capacity decay was reduced from 40%/100 cycles to 15%/100 cycles. Moreover, the discharge capacity with the polymer coating was ∼10% higher than the bare counterpart, with an initial discharge capacity of 1140 mAh/g and a stable discharge capacity of >600 mAh/g after 150 cycles at C/5 rate. We believe that this conductive polymer coating method represents an exciting direction for enhancing the device performance of Li-S batteries and can be applicable to other electrode materials in lithium ion batteries. © 2011 American Chemical Society.

  15. Optimal bidding strategy of battery storage in power markets considering performance based regulation and battery cycle life

    DEFF Research Database (Denmark)

    He, Guannan; Chen, Qixin; Kang, Chongqing

    2016-01-01

    to reduce the complexity of the model. This novel bidding model would help investor-owned battery storages better decide their bidding and operational schedules and investors to estimate the battery storage’s economic viability. The validity of the proposed model is proven by case study results....

  16. Evaluating the Performance of a Battery Using Temperature and Voltage Profiles and a Battery-Resistor Circuit Module

    Science.gov (United States)

    Sawyer, Bryan; Ji, Michelle; Gordon, Michael J.; Suppes, Galen J.

    2010-01-01

    An experimental learning module has been developed to study the mass and energy balance involved with operation of an AA Alkaline battery under a load current. An extension of the module allows evaluation of laboratory-assembled batteries using granular anodic/cathodic materials. The system allows load resistance to be varied and measures voltage…

  17. Modeling of electric vehicle battery for vehicle-to-grid applications

    DEFF Research Database (Denmark)

    Pang, Ying; Brady, Cormac; Pellegrino, Giustino

    2013-01-01

    Electric vehicle battery models are essential when performing analysis of EV systems. The battery package of electric vehicles is complicated and unpredictable because of its chemical based functioning. In this paper, a battery model is presented with a number of internal and external factors taken...

  18. Performance of a vanadium redox flow battery with a VANADion membrane

    International Nuclear Information System (INIS)

    Zhou, X.L.; Zhao, T.S.; An, L.; Zeng, Y.K.; Zhu, X.B.

    2016-01-01

    Highlights: • Performance of the VANADion membrane in flow batteries is evaluated. • The battery with present membrane shows good rate capability. • The battery with present membrane offers good capacity retention. • The high performance and low cost make the membrane promising in VRFBs. - Abstract: Conventional vanadium redox flow batteries (VRFBs) using Nafion 115 suffered from issues associated with high ohmic resistance and high capital cost. In this work, we report a commercial membrane (VANADion), consisting of a porous layer and a dense Nafion layer, as a promising alternative to Nafion 115. In the dual-layer structure, the porous layer (∼210 μm) can offer a high ionic conductivity and the dense Nafion layer (∼20 μm) can depress the convective flow of electrolyte through the membrane. By comparing with the conventional Nafion 115 in a VRFB, it is found that the change from the conventional Nafion 115 to the composite one results in an increase in the energy efficiency from 71.3% to 76.2% and an increase in the electrolyte utilization from 54.1% to 68.4% at a current density of as high as 240 mA cm"−"2. In addition, although two batteries show the comparable cycling performance at current densities ranging from 80 mA cm"−"2 to 240 mA cm"−"2, the composite membrane is estimated to be significantly cheaper than the conventional Nafion 115 due to the fact that the porous layer is rather cost-effective and the dense Nafion layer is rather thin. The impressive combination of desirable performance and low cost makes this composite membrane highly promising in the VRFB applications.

  19. Internal and external market orientation as organizational resources - consequences for market and financial performance

    Directory of Open Access Journals (Sweden)

    Boris Snoj

    2010-11-01

    Full Text Available The concept of internal marketing has been discussed in marketing literature for over 30 years. Despite this fact there is little theoretical and empirical evidence of the way in which the internal market orientation impacts market and financial performance. On the other hand, there is considerable empirical evidence concerning the impact of the external market orientation on market and financial performance. Consequently, very few research projects have dealt with the impact of both market orientations on the performance of companies. In this paper a structural model was constructed, consisting of the internal market orientation, external market orientation, market performance and financial performance. With the help of the structural equation model the hypothesis that the internal market orientation is a significant predecessor of the external market orientation was confirmed. The external market orientation was found to significantly influence market as well as financial performance.

  20. High-Performance Oligomeric Catholytes for Effective Macromolecular Separation in Nonaqueous Redox Flow Batteries.

    Science.gov (United States)

    Hendriks, Koen H; Robinson, Sophia G; Braten, Miles N; Sevov, Christo S; Helms, Brett A; Sigman, Matthew S; Minteer, Shelley D; Sanford, Melanie S

    2018-02-28

    Nonaqueous redox flow batteries (NRFBs) represent an attractive technology for energy storage from intermittent renewable sources. In these batteries, electrical energy is stored in and extracted from electrolyte solutions of redox-active molecules (termed catholytes and anolytes) that are passed through an electrochemical flow cell. To avoid battery self-discharge, the anolyte and catholyte solutions must be separated by a membrane in the flow cell. This membrane prevents crossover of the redox active molecules, while simultaneously allowing facile transport of charge-balancing ions. A key unmet challenge for the field is the design of redox-active molecule/membrane pairs that enable effective electrolyte separation while maintaining optimal battery properties. Herein, we demonstrate the development of oligomeric catholytes based on tris(dialkylamino)cyclopropenium (CP) salts that are specifically tailored for pairing with size-exclusion membranes composed of polymers of intrinsic microporosity (PIMs). Systematic studies were conducted to evaluate the impact of oligomer size/structure on properties that are crucial for flow battery performance, including cycling stability, charge capacity, solubility, electron transfer kinetics, and crossover rates. These studies have led to the identification of a CP-derived tetramer in which these properties are all comparable, or significantly improved, relative to the monomeric counterpart. Finally, a proof-of-concept flow battery is demonstrated by pairing this tetrameric catholyte with a PIM membrane. After 6 days of cycling, no crossover is detected, demonstrating the promise of this approach. These studies provide a template for the future design of other redox-active oligomers for this application.

  1. Architecture for improved mass transport and system performance in redox flow batteries

    Science.gov (United States)

    Houser, Jacob; Pezeshki, Alan; Clement, Jason T.; Aaron, Douglas; Mench, Matthew M.

    2017-05-01

    In this work, electrochemical performance and parasitic losses are combined in an overall system-level efficiency metric for a high performance, all-vanadium redox flow battery. It was found that pressure drop and parasitic pumping losses are relatively negligible for high performance cells, i.e., those capable of operating at a high current density while at a low flow rate. Through this finding, the Equal Path Length (EPL) flow field architecture was proposed and evaluated. This design has superior mass transport characteristics in comparison with the standard serpentine and interdigitated designs at the expense of increased pressure drop. An Aspect Ratio (AR) design is discussed and evaluated, which demonstrates decreased pressure drop compared to the EPL design, while maintaining similar electrochemical performance under most conditions. This AR design is capable of leading to improved system energy efficiency for flow batteries of all chemistries.

  2. Logistics-production, logistics-marketing and external integration: Their impact on performance

    OpenAIRE

    Giménez, Cristina; Ventura, Eva

    2003-01-01

    Highly competitive environments are leading companies to implement Supply Chain Management (SCM) to improve performance and gain a competitive advantage. SCM involves integration, co-ordination and collaboration across organisations and throughout the supply chain. It means that SCM requires internal (intraorganisational) and external (interorganisational) integration. This paper examines the Logistics-Production and Logistics- Marketing interfaces and their relation with the external integra...

  3. Short-range contacts govern the performance of industry-relevant battery cathodes

    Science.gov (United States)

    Morelly, Samantha L.; Alvarez, Nicolas J.; Tang, Maureen H.

    2018-05-01

    Fundamental understanding of how processing affects composite battery electrode structure and performance is still lacking, especially for industry-relevant electrodes with low fractions of inactive material. This work combines rheology, electronic conductivity measurements, and battery rate capability tests to prove that short-range electronic contacts are more important to cathode rate capability than either ion transport or long-range electronic conductivity. LiNi0.33Mn0.33Co0.33O2, carbon black, and polyvinylidene difluoride in 1-methyl-2-pyrrolidinone represent a typical commercial electrode with films. Improvements in battery rate capability at constant electrode porosity do not correlate to electronic conductivity, but rather show an optimum fraction of free carbon. Simple comparison of rate capability in electrodes with increased total carbon loading (3 wt%) shows improvement for all fractions of free carbon. These results clearly indicate that ion transport cannot be limiting and highlight the critical importance of short-range electronic contacts for controlling battery performance.

  4. Performance analysis of hybrid PV/diesel/battery system using HOMER: A case study Sabah, Malaysia

    International Nuclear Information System (INIS)

    Halabi, Laith M.; Mekhilef, Saad; Olatomiwa, Lanre; Hazelton, James

    2017-01-01

    Highlights: • The performance of two decentralized power stations in Malaysia has been studied. • All possible scenarios of hybrid PV/diesel/battery system have been analyzed. • A comparison with the optimum design was included in this work using HOMER. • Sensitivity analysis showing the impact of main factors on the system was examined. • The advantages/disadvantages of utilizing each scenario are showed and clarified. - Abstract: This study considered two decentralized power stations in Sabah, Malaysia; each contains different combination of photovoltaic (PV), diesel generators, system converters, and storage batteries. The work was built upon previous related site surveys and data collections from each site. Verification of the site data sets, simulation of different operational scenarios, and a comparison with the optimum design were all considered in the work. This includes all possible standalone diesel generators, hybrid PV/diesel/battery, and 100% PV/battery scenarios for the proposed stations. HOMER software has been used in the modeling entire systems. The operational behaviors of different PV penetration levels were analyzed to accurately quantify the impact of PV integration. The performance of these stations was analyzed based on technical, economic and environmental constraints, besides, placing emphasis on comparative cost analysis between different operational scenarios. The results satisfied the load demand with the minimum total net present cost (NPC) and levelized cost of energy (LCOE). Moreover, sensitivity analysis was carried out to represents the effects of changing main parameters, such as; fuel, PV, battery prices, and load demand (load growth) on the system performance. Comparison of all operational behaviors scenarios was carried out to elucidate the advantages/disadvantages of utilizing each scenario. The impact of different PV penetration levels on the system performance and the generation of harmful emissions is also

  5. Performance Characterization of a Lithium-ion Gel Polymer Battery Power Supply System for an Unmanned Aerial Vehicle

    Science.gov (United States)

    Reid, Concha M.; Manzo, Michelle A.; Logan, Michael J.

    2004-01-01

    Unmanned aerial vehicles (UAVs) are currently under development for NASA missions, earth sciences, aeronautics, the military, and commercial applications. The design of an all electric power and propulsion system for small UAVs was the focus of a detailed study. Currently, many of these small vehicles are powered by primary (nonrechargeable) lithium-based batteries. While this type of battery is capable of satisfying some of the mission needs, a secondary (rechargeable) battery power supply system that can provide the same functionality as the current system at the same or lower system mass and volume is desired. A study of commercially available secondary battery cell technologies that could provide the desired performance characteristics was performed. Due to the strict mass limitations and wide operating temperature requirements of small UAVs, the only viable cell chemistries were determined to be lithium-ion liquid electrolyte systems and lithium-ion gel polymer electrolyte systems. Two lithium-ion gel polymer cell designs were selected as candidates and were tested using potential load profiles for UAV applications. Because lithium primary batteries have a higher specific energy and energy density, for the same mass and volume allocation, the secondary batteries resulted in shorter flight times than the primary batteries typically provide. When the batteries were operated at lower ambient temperatures (0 to -20 C), flight times were even further reduced. Despite the reduced flight times demonstrated, for certain UAV applications, the secondary batteries operated within the acceptable range of flight times at room temperature and above. The results of this testing indicate that a secondary battery power supply system can provide some benefits over the primary battery power supply system. A UAV can be operated for hundreds of flights using a secondary battery power supply system that provides the combined benefits of rechargeability and an inherently safer

  6. Lithium/Manganese Dioxide (Li/MnO(2)) Battery Performance Evaluation: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Ingersoll, D.; Clark, N.H.

    1999-04-01

    In February 1997, under the auspices of the Product Realization Program, an initiative to develop performance models for lithium/manganese dioxide-based batteries began. As a part of this initiative, the performance characteristics of the cells under a variety of conditions were determined, both for model development and for model validation. As a direct result of this work, it became apparent that possible Defense Program (DP) uses for batteries based on this cell chemistry existed. A larger effort aimed at mapping the performance envelope of this chemistry was initiated in order to assess the practicality of this cell chemistry, not only for DP applications, but also for other uses. The work performed included an evaluation of the cell performance as a function of a number of variables, including cell size, manufacturer, current, pulse loads, constant current loads, safety, etc. In addition, the development of new evaluation techniques that would apply to any battery system, such as those related to reliability assessments began. This report describes the results of these evaluations.

  7. A Lithium-Air Battery Stably Working at High Temperature with High Rate Performance.

    Science.gov (United States)

    Pan, Jian; Li, Houpu; Sun, Hao; Zhang, Ye; Wang, Lie; Liao, Meng; Sun, Xuemei; Peng, Huisheng

    2018-02-01

    Driven by the increasing requirements for energy supply in both modern life and the automobile industry, the lithium-air battery serves as a promising candidate due to its high energy density. However, organic solvents in electrolytes are likely to rapidly vaporize and form flammable gases under increasing temperatures. In this case, serious safety problems may occur and cause great harm to people. Therefore, a kind of lithium-air that can work stably under high temperature is desirable. Herein, through the use of an ionic liquid and aligned carbon nanotubes, and a fiber shaped design, a new type of lithium-air battery that can effectively work at high temperatures up to 140 °C is developed. Ionic liquids can offer wide electrochemical windows and low vapor pressures, as well as provide high thermal stability for lithium-air batteries. The aligned carbon nanotubes have good electric and heat conductivity. Meanwhile, the fiber format can offer both flexibility and weavability, and realize rapid heat conduction and uniform heat distribution of the battery. In addition, the high temperature has also largely improved the specific powers by increasing the ionic conductivity and catalytic activity of the cathode. Consequently, the lithium-air battery can work stably at 140 °C with a high specific current of 10 A g -1 for 380 cycles, indicating high stability and good rate performance at high temperatures. This work may provide an effective paradigm for the development of high-performance energy storage devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. How a gel polymer electrolyte affects performance of lithium/sulfur batteries

    International Nuclear Information System (INIS)

    Zhang, Sheng S.; Tran, Dat T.

    2013-01-01

    Highlights: •Conventional separator is coated with a 50PEO-50SiO 2 (wt.%) composite layer. •Composite coating increases tensile strength and electrolyte wettability. •Coated separator offers an alternative approach for making gel polymer Li/S battery. •Li/S battery takes benefits of gel polymer electrolyte at the expense of capacity. -- Abstract: Gel polymer electrolyte (GPE) and composite gel polymer electrolyte (CGPE) have been widely employed to improve the safety and cycling performance of rechargeable lithium and lithium-ion batteries. In order to determine whether this approach is applicable to lithium/sulfur (Li/S) battery, we examine the effect of CGPE on the cycling and storage performances of Li/S cells by comparing a 50PEO-50SiO 2 (wt.%) composite coated separator (C-separator) with a pristine separator (P-separator). Results show that the composite coating significantly enhances the wettability of liquid electrolyte on the separator and that resulting CGPE can tightly glue the separator and electrode together. In comparison with the P-separator, the C-separator offers Li/S cells similar capacity retention and rate capability; however it greatly affects the specific capacity of sulfur. The analysis on the impedance spectrum of a lithium polysulfide (PS) solution reveal that the reduction of sulfur specific capacity is due to the high viscosity of the CGPE and the strong adsorption of SiO 2 filler to the PS species, which trap PS species in the separator and hence reduce the utilization of sulfur active material. Therefore, the benefits of the GPE and CGPE to the Li/S batteries can be taken only at the expense of sulfur specific capacity

  9. A high-performance carbon nanoparticle-decorated graphite felt electrode for vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Wei, L.; Zhao, T.S.; Zhao, G.; An, L.; Zeng, L.

    2016-01-01

    Highlights: • Propose a carbon nanoparticle-decorated graphite felt electrode for VRFBs. • The energy efficiency is up to 84.8% at 100 mA cm"−"2. • The new electrode allows the peak power density to reach 508 mW cm"−"2. - Abstract: Increasing the performance of vanadium redox flow batteries (VRFBs), especially the energy efficiency and power density, is critically important to reduce the system cost to a level for widespread commercialization. Unlike conventional VRFBs with flow-through structure, in this work we create a VRFB featuring a flow-field structure with a carbon nanoparticle-decorated graphite felt electrode for the battery. This novel structure, exhibiting a significantly reduced ohmic loss through reducing electrode thickness, an increased surface area and improved electrocatalytic activity by coating carbon nanoparticles, allows the energy efficiency up to 84.8% at a current density of as high as 100 mA cm"−"2 and the peak power density to reach a value of 508 mW cm"−"2. In addition, it is demonstrated that the battery with this proposed structure exhibits a substantially improved rate capability and capacity retention as opposed to conventional flow-through structured battery with thick graphite felt electrodes.

  10. Analysis of Sustainable Performance in Romania’s Local Public Administrations: An External Stakeholders Perspective

    Directory of Open Access Journals (Sweden)

    Diana MIHAIU

    2016-12-01

    Full Text Available Building a sustainable performance system at the level of the local public administrations must have as starting point the local public administration’s (LPA mission and must go down to the level of the individual. This system must follow the external performance that it delivers to the citizens, the outcomes generated, but also the internal performance which suggests how to achieve the external performance. We propose in this regard the simultaneous use of the Balanced Scorecard tool for managing the internal performance and the Public Service Value Model for measuring the external performance measurement which derives from the organization's mission. In the second part of the work we analyzed comparatively the external performance created by the county capitals of Romania in the year 2013 using the Public Service Value Model (PSVM. Based on this analysis, the county capitals of Romania can be divided in the following categories: high performance organizations (value driven, budget conscious organizations, low performance organizations (sleeping giants and quality conscious organizations. This classification is useful both for the external and internal stakeholders because it shows the efficiency of public money spending and the areas in which the LPA is performing well, and also the ones that need to be improved.

  11. Improving the Performance Attributes of Plug-in Hybrid Electric Vehicles in Hot Climates through Key-Off Battery Cooling

    Directory of Open Access Journals (Sweden)

    Sina Shojaei

    2017-12-01

    Full Text Available Ambient conditions can have a significant impact on the average and maximum temperature of the battery of electric and plug-in hybrid electric vehicles. Given the sensitivity of the ageing mechanisms of typical battery cells to temperature, a significant variability in battery lifetime has been reported with geographical location. In addition, high battery temperature and the associated cooling requirements can cause poor passenger thermal comfort, while extreme battery temperatures can negatively impact the power output of the battery, limiting the available electric traction torque. Avoiding such issues requires enabling battery cooling even when the vehicle is parked and not plugged in (key-off, but the associated extra energy requirements make applying key-off cooling a non-trivial decision. In this paper, a representative plug-in parallel hybrid electric vehicle model is used to simulate a typical 24-h duty cycle to quantify the impact of hot ambient conditions on three performance attributes of the vehicle: the battery lifetime, passenger thermal comfort and fuel economy. Key-off cooling is defined as an optimal control problem in view of the duty cycle of the vehicle. The problem is then solved using the dynamic programming method. Controlling key-off cooling through this method leads to significant improvements in the battery lifetime, while benefiting the fuel economy and thermal comfort attributes. To further improve the battery lifetime, partial charging of the battery is considered. An algorithm is developed that determines the optimum combination of key-off cooling and the level of battery charge. Simulation results confirm the benefits of the proposed method.

  12. Study Protocol on Cognitive Performance in Bulgaria, Croatia, and the Netherlands: The Normacog Brief Battery

    Directory of Open Access Journals (Sweden)

    Lea Jakob

    2016-10-01

    Full Text Available The Normacog Brief Battery (NBB provides a comprehensive overview of an individual’s cognitive functioning within a short amount of time. It was originally developed for the Spanish population in Spain. However, there is a considerable need for brief batteries in clinical neuropsychological assessment, especially in eastern European countries. Cultural background and other individual characteristics—such as age, level of education, and sex—are shown to influence both cognition and patients’ performance on neuropsychological tests. Therefore, it is important to develop understanding of how and why culture impacts on cognitive testing and determine which sociodemographic variables affect cognitive performance. The current study aims to translate, adapt, and standardize the NBB in Bulgaria, Croatia, and the Netherlands, and to analyze the effect of sex, age, and education level on cognitive performance between these three countries. This brief battery assesses eleven cognitive domains, including those most currently relevant in cognition such as premorbid intelligence, attention, executive function, processing speed, and memory. The translation and adaptation of the battery for different cultures will be done using the back-translation process. After exclusion criteria, the current study will include a total sample of three hundred participants (≥18 years old. The samples of 100 participants per country will be balanced through the consideration of their age and level of education. Effects of the sociodemographic variables (age, level of education, and sex on cognitive performance are expected. Furthermore, this relationship is expected to differ across countries. A multivariate hierarchical linear regression will be used and exploratory analysis will be carried out to investigate further effects. The results will be particularly valuable for future research and assessment in cognitive performance. The growing demand for accurate and fast

  13. Impaired Neurobehavioural Performance in Untreated Obstructive Sleep Apnea Patients Using a Novel Standardised Test Battery

    Directory of Open Access Journals (Sweden)

    Angela L. D'Rozario

    2018-05-01

    Full Text Available Objective/BackgroundAlthough polysomnography (PSG is the gold-standard measure for assessing disease severity in obstructive sleep apnea (OSA, it has limited value in identifying individuals experiencing significant neurobehavioural dysfunction. This study used a brief and novel computerised test battery to examine neurobehavioural function in adults with and without OSA.Patients/Methods204 patients with untreated OSA [age 49.3 (12.5 years; body mass index, [BMI] 33.6 (8.0 kg/m2; Epworth sleepiness scale 12 (4.9/24; apnea hypopnea index 33.6 (25.8/h] and 50 non-OSA participants [age 39.2 (14.0 years; BMI 25.8 (4.2 kg/m2, ESS 3.6 (2.3/24]. All participants completed a computerised neurobehavioural battery during the daytime in the sleep clinic. The OSA group subsequently underwent an overnight PSG. The 30 min test battery assessed cognitive domains of visual spatial scanning and selective attention (Letter Cancellation Test, executive function (Stroop task and working memory (2- and 3-Back tasks, and a validated sustained attention task (psychomotor vigilance task, PVT. Group differences in performance were compared. Associations between disease severity and performance were examined in the OSA group.ResultsAfter controlling for age, gender and education, OSA patients demonstrated impaired performance on the Stroop-Text, 2 and 3-Back tasks, and the PVT compared with the non-OSA group. OSA patients had worse performance on the LCT with fewer average hits albeit with better accuracy. Some OSA polysomnographic disease severity measures were weakly correlated with performance.ConclusionsThis brief test battery may provide a sensitive, standardised method of assessing daytime dysfunction in OSA.

  14. Nano-hydroxyapatite as an Efficient Polysulfide Absorbent for High-performance Li-S Batteries

    International Nuclear Information System (INIS)

    Liu, Naiqiang; Ai, Fei; Wang, Weikun; Shao, Hongyuan; Zhang, Hao; Wang, Anbang; Xu, Zhichuan J.; Huang, Yaqin

    2016-01-01

    Highlights: • Nano-HA has been demonstrated as an efficient polysulfide absorbent. • The shuttle effect of polysulfide in Li-S battery has been confined by the nano-HA. • Nano-HA used as additive improved electrochemical performance of Li-S battery. - Abstract: Lithium-sulfur (Li-S) battery is regarded as one of the most promising candidates for developing advanced energy storage system, but the polysulfide shuttle effect remains the biggest obstacle for its practical application. In this work, nano-hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)) was used as an additive in the sulfur cathode and carbon-coated separator to prevent the polysulfide shuttle effect and thus to achieve the high performance. The sulfur cathode with nano-hydroxyapatite exhibited a higher reversible capacity and a more stable cycling performance than that of the pristine sulfur cathode. The improved capacity retention from 58% (100th) to 73% (200th) after introducing nano-hydroxyapatite into the sulfur cathode confirmed its strong polysulfide absorption ability. Furthermore, a nano-hydroxyapatite modified separator was developed to suppress the polysulfide shuttle effect and to facilitate the reutilization of sulfur species. The nano-hydroxyapatite particles served as polysulfide absorbents to bind polysulfides and suppress their diffusion to the anode. The batteries assembled with this separator exhibited a high reversible capacity of 886 mAhg −1 at 0.1C and 718 mAh g −1 at 0.5C after 200 cycles, with a low capacity fading of ∼0.10-0.11% per-cycle. At the highest sulfur loading of 4.5 mg cm −2 used for practical applications, the reversible areal capacity was much higher than the areal capacity (4 mAh cm −2 ) of commercial lithium-ion batteries. Therefore, the strategy using nano-hydroxyapatite as polysulfide absorbent shows great potential for solving the polysulfide shuttle problem and developing high performance Li-S batteries.

  15. Experimental analysis on the performance of lithium based batteries for road full electric and hybrid vehicles

    International Nuclear Information System (INIS)

    Capasso, Clemente; Veneri, Ottorino

    2014-01-01

    Highlights: • Performance analysis for lithium storage technologies, such as Li[NiCoMn]O 2 and LiFePO 4 batteries. • Actual capacity of lithium technologies analyzed almost close to their nominal capacity also for high discharging current. • The charging efficiency for Li[NiCoMn]O 2 positively affects the regenerative breaking and fast recharging operations. • The analyzed battery packs follow dynamic power requirements on performed road driving cycles. • Experimental results demonstrate driving range is much higher when battery packs are based on lithium technology. - Abstract: This paper deals with an experimental evaluation regarding the real performance of lithium based energy storage systems for automotive applications. In particular real working operations of different lithium based storage system technologies, such as Li[NiCoMn]O 2 and LiFePO 4 batteries, are compared in this work from the point of view of their application in supplying full electric and hybrid vehicles, taking as a reference the well-known behavior of lead acid batteries. For this purpose, the experimental tests carried out in laboratory are firstly performed on single storage modules in stationary conditions. In this case the related results are obtained by means of a bidirectional cycle tester based on the IGBT technology, and consent to evaluate, compare and contrast charge/discharge characteristics and efficiency at constant values of current/voltage/power for each storage technology analyzed. Then, lithium battery packs are tested in supplying a 1.8 kW electric power train using a laboratory test bench, based on a 48 V DC bus and specifically configured to simulate working operations of electric vehicles on the road. For this other experimentation the test bench is equipped with an electric brake and acquisition/control system, able to represent in laboratory the real vehicle conditions and road characteristics on predefined driving cycles at different slopes. The obtained

  16. Directly Formed Alucone on Lithium Metal for High-Performance Li Batteries and Li-S Batteries with High Sulfur Mass Loading.

    Science.gov (United States)

    Chen, Lin; Huang, Zhennan; Shahbazian-Yassar, Reza; Libera, Joseph A; Klavetter, Kyle C; Zavadil, Kevin R; Elam, Jeffrey W

    2018-02-28

    Lithium metal is considered the "holy grail" of next-generation battery anodes. However, severe parasitic reactions at the lithium-electrolyte interface deplete the liquid electrolyte and the uncontrolled formation of high surface area and dendritic lithium during cycling causes rapid capacity fading and battery failure. Engineering a dendrite-free lithium metal anode is therefore critical for the development of long-life batteries using lithium anodes. In this study, we deposit a conformal, organic/inorganic hybrid coating, for the first time, directly on lithium metal using molecular layer deposition (MLD) to alleviate these problems. This hybrid organic/inorganic film with high cross-linking structure can stabilize lithium against dendrite growth and minimize side reactions, as indicated by scanning electron microscopy. We discovered that the alucone coating yielded several times longer cycle life at high current rates compared to the uncoated lithium and achieved a steady Coulombic efficiency of 99.5%, demonstrating that the highly cross-linking structured material with great mechanical properties and good flexibility can effectively suppress dendrite formation. The protected Li was further evaluated in lithium-sulfur (Li-S) batteries with a high sulfur mass loading of ∼5 mg/cm 2 . After 140 cycles at a high current rate of ∼1 mA/cm 2 , alucone-coated Li-S batteries delivered a capacity of 657.7 mAh/g, 39.5% better than that of a bare lithium-sulfur battery. These findings suggest that flexible coating with high cross-linking structure by MLD is effective to enable lithium protection and offers a very promising avenue for improved performance in the real applications of Li-S batteries.

  17. THE RELATIONSHIP OF COMPANY PERFORMANCE WITH EXTERNAL STAKEHOLDER SATISFACTION (STUDY AT INDUSTRIAL METAL PROCESSING COMPANY IN SULAWESI)

    OpenAIRE

    Amar, Muh Yunus

    2011-01-01

    Attainment of company performance relates to participation of its external stakeholder. External stakeholder here defined as the group which having importance with company and cannot be controlled by company management. Existence of external stakeholder becomes of vital importance and influential to performance and continuity of company life (Kasali, 1990). Therefore, management of the company needs to paying attention more to the importance of the external stakeholder. External stakeholders ...

  18. The performance and efficiency of four motor/controller/battery systems for the simpler electric vehicles

    Science.gov (United States)

    Shipps, P. R.

    1980-01-01

    A test and analysis program performed on four complete propulsion systems for an urban electric vehicle (EV) is described and results given. A dc series motor and a permanent magnet (PM) motor were tested, each powered by an EV battery pack and controlled by (1) a series/parallel voltage-switching (V-switch) system; and (2) a system using a pulse width modulation, 400 Hz transistorized chopper. Dynamometer tests were first performed, followed by eV performance predictions and data correlating road tests. During dynamometer tests using chopper control; current, voltage, and power were measured on both the battery and motor sides of the chopper, using three types of instrumentation. Conventional dc instruments provided adequate accuracy for eV power and energy measurements, when used on the battery side of the controller. When using the chopper controller, the addition of a small choke inductor improved system efficiency in the lower duty cycle range (some 8% increase at 50% duty cycle) with both types of motors. Overall system efficiency rankings during road tests were: (1) series motor with V-switch; (2) PM motor with V-switch; (3) series motor with chopper; and (4) PM motor with chopper. Chopper control of the eV was smoother and required less driver skill than V-switch control.

  19. Electrospun polyacrylonitrile/polyurethane composite nanofibrous separator with electrochemical performance for high power lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zainab, Ghazala [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Wang, Xianfeng, E-mail: wxf@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Key Laboratory of High Performance Fibers & Products, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Nanofibers Research Center, Modern Textile Institute, Donghua University, Shanghai 200051 (China); Yu, Jianyong [Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Key Laboratory of High Performance Fibers & Products, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Nanofibers Research Center, Modern Textile Institute, Donghua University, Shanghai 200051 (China); Zhai, Yunyun; Ahmed Babar, Aijaz; Xiao, Ke [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Ding, Bin, E-mail: binding@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Key Laboratory of High Performance Fibers & Products, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620 (China); Nanofibers Research Center, Modern Textile Institute, Donghua University, Shanghai 200051 (China)

    2016-10-01

    Lithium ion batteries (LIBs) for high performance require separators with auspicious reliability and safety. Keeping LIBs reliability and safety in view, microporous polyacrylonitrile (PAN)/polyurethane (PU) nonwoven composite separator have been developed by electrospinning technique. The physical, electrochemical and thermal properties of the PAN/PU separator were characterized. Improved ionic conductivity up to 2.07 S cm{sup −1}, high mechanical strength (10.38 MPa) and good anodic stability up to 5.10 V are key outcomes of resultant membranes. Additionally, high thermal stability displaying only 4% dimensional change after 0.5 h long exposure to 170 °C in an oven, which could be valuable addition towards the safety of LIBs. Comparing to commercialized polypropylene based separators, resulting membranes offered improved internal short-circuit protection function, offering better rate capability and enhanced capacity retention under same observation conditions. These fascinating characteristics endow these renewable composite nonwovens as promising separators for high power LIBs battery. - Highlights: • The PAN/PU based separators were prepared by multi-needle electrospinning technique. • The electrospun separators displays good mechanical properties and thermal stability. • These separators exhibit good wettability with liquid electrolyte, high ion conductivity and internal short-circuit protection. • Nanofibrous composite nonwoven possesses stable cyclic performance which give rise to acceptable battery performances.

  20. The influence of operational parameters on the performance of an undivided zinc–cerium flow battery

    International Nuclear Information System (INIS)

    Leung, P.K.; Ponce de Leon, C.; Walsh, F.C.

    2012-01-01

    Highlights: ► The performance of an undivided zinc–cerium flow battery under different conditions of temperature, concentration and electrolyte flow rate, was evaluated. ► Mixed electrolytes were considered; methanesulfonate and sulfate anions were tested. ► In a 30 min charge/discharge at 20 mA cm −2 , charge and energy efficiencies were 82% and 72%, respectively. ► After 4 h charge, the conversion of Ce(III) to Ce(IV) became less efficient with the oxygen evolution reaction becoming more favored. ► After a larger number of cycles the carbon felt electrode was electro- and chemically-oxidized by Ce(IV) leading to degradation of the positive electrode. - Abstract: An undivided zinc–cerium redox flow battery was studied under a wide range of operational conditions, including: (i) electrolyte composition; the concentrations of ([Zn 2+ ], [Ce 3+ ] and [H + ]), (ii) current density (0–80 mA cm −2 ), (iii) electrolyte flow linear velocity (0.64–7.0 cm s −1 ) and (iv) temperature (20–60 °C). The charge efficiency increased at higher current densities and at higher electrolyte flow velocities. Unlike the divided zinc–cerium system, the charge–discharge performance decreased at higher temperature, since oxygen evolution became increasingly favored at the positive electrode. The use of a low acid concentration led to a poor conversion of Ce(III) to Ce(IV) ions during the discharge cycle. Mixed electrolytes containing methanesulfonate and sulfate anions have been evaluated at a high Ce(III) ion concentration, e.g. 0.4 mol dm −3 . After charging the battery for 4 h, the conversion of Ce(III) to Ce(IV) ions became less efficient over time due to a greater fraction of the current being used in oxygen evolution. Critical aspects for improvements in the battery performance are considered.

  1. Does external technology acquisition determine export performance? Evidence from Chinese manufacturing firms

    DEFF Research Database (Denmark)

    Wang, Yuandi; Cao, Wei; Zhou, Zhao

    2013-01-01

    understanding of the determinants of export performance by examining the impact of the inter-organizational dimension of innovation strategy to export performance, which has been ignored in the prevailing “strategy tripod” perspective of exporting research. This study is based on a sample of 141 Chinese...... indigenous manufacturing firms that engaged in inward technology licensing between 2000 and 2003. The empirical results indicate that external technology acquisitions positively influence Chinese firms’ export performance. Moreover the exporting performance of using external technology varies depending...

  2. Computer simulations of the influence of geometry in the performance of conventional and unconventional lithium-ion batteries

    International Nuclear Information System (INIS)

    Miranda, D.; Costa, C.M.; Almeida, A.M.; Lanceros-Méndez, S.

    2016-01-01

    Highlights: • The influence of geometries in lithium-ion battery performance is analyzed. • Conventional and unconventional battery geometries are investigated. • Unconventional geometries include horseshoe, spiral, ring, antenna and gear batteries. • The best capacity value at 330 C is obtained for the interdigitated geometry. • The capacity value is dependent on thickness and collectors position. - Abstract: In order to optimize battery performance, different geometries have been evaluated taking into account their suitability for different applications. These different geometries include conventional, interdigitated batteries and unconventional geometries such as horseshoe, spiral, ring, antenna and gear batteries. The geometry optimization was performed by the finite element method, applying the Doyle/Fuller/Newman model. At 330 C, the capacity values for conventional, ring, spiral, horseshoe, gear and interdigitated geometries are 0.58 A h m"−"2, 149 A h m"−"2, 182 A h m"−"2, 216 A h m"−"2, 289 A h m"−"2 and 318 A h m"−"2, respectively. The delivered capacity depends on geometrical parameters such as maximum distance for the ions to move to the current collector, d-max, distance between of current collectors, d-cc, as well as the thickness of separator and electrodes, allowing to tailor battery performance and geometry for specific applications.

  3. Silicene Flowers: A Dual Stabilized Silicon Building Block for High-Performance Lithium Battery Anodes.

    Science.gov (United States)

    Zhang, Xinghao; Qiu, Xiongying; Kong, Debin; Zhou, Lu; Li, Zihao; Li, Xianglong; Zhi, Linjie

    2017-07-25

    Nanostructuring is a transformative way to improve the structure stability of high capacity silicon for lithium batteries. Yet, the interface instability issue remains and even propagates in the existing nanostructured silicon building blocks. Here we demonstrate an intrinsically dual stabilized silicon building block, namely silicene flowers, to simultaneously address the structure and interface stability issues. These original Si building blocks as lithium battery anodes exhibit extraordinary combined performance including high gravimetric capacity (2000 mAh g -1 at 800 mA g -1 ), high volumetric capacity (1799 mAh cm -3 ), remarkable rate capability (950 mAh g -1 at 8 A g -1 ), and excellent cycling stability (1100 mA h g -1 at 2000 mA g -1 over 600 cycles). Paired with a conventional cathode, the fabricated full cells deliver extraordinarily high specific energy and energy density (543 Wh kg ca -1 and 1257 Wh L ca -1 , respectively) based on the cathode and anode, which are 152% and 239% of their commercial counterparts using graphite anodes. Coupled with a simple, cost-effective, scalable synthesis approach, this silicon building block offers a horizon for the development of high-performance batteries.

  4. Effect of extreme temperatures on battery charging and performance of electric vehicles

    Science.gov (United States)

    Lindgren, Juuso; Lund, Peter D.

    2016-10-01

    Extreme temperatures pose several limitations to electric vehicle (EV) performance and charging. To investigate these effects, we combine a hybrid artificial neural network-empirical Li-ion battery model with a lumped capacitance EV thermal model to study how temperature will affect the performance of an EV fleet. We find that at -10 °C, the self-weighted mean battery charging power (SWMCP) decreases by 15% compared to standard 20 °C temperature. Active battery thermal management (BTM) during parking can improve SWMCP for individual vehicles, especially if vehicles are charged both at home and at workplace; the median SWMCP is increased by over 30%. Efficiency (km/kWh) of the vehicle fleet is maximized when ambient temperature is close to 20 °C. At low (-10 °C) and high (+40 °C) ambient temperatures, cabin preconditioning and BTM during parking can improve the median efficiency by 8% and 9%, respectively. At -10 °C, preconditioning and BTM during parking can also improve the fleet SOC by 3-6%-units, but this also introduces a ;base; load of around 140 W per vehicle. Finally, we observe that the utility of the fleet can be increased by 5%-units by adding 3.6 kW chargers to workplaces, but further improved charging infrastructure would bring little additional benefit.

  5. The relationship between IQ and performance on the MATRICS consensus cognitive battery

    Directory of Open Access Journals (Sweden)

    Christine Mohn

    2014-06-01

    Full Text Available The associations between IQ and individual tests of neurocognitive function are well studied. However, there is a lack of information as to how IQ relates to performance on neuropsychological test batteries as a whole and in the same individuals. In this study, 250 healthy participants aged 20-69 years were tested with the Wechsler Abbreviated Scale of Intelligence (WASI and the MATRICS Consensus Cognitive Battery (MCCB. In correlation analyses, IQ was significantly related to all MCCB scores, except the Social Cognition domain. Hierarchical regression analyses including gender, age, and education confirmed this association. For overall cognitive function, 50% of the variance was explained by IQ and demographic characteristics. For the domains Speed of Processing, Working Memory, Visual and Verbal Learning, IQ explained a larger proportion of the variance than the demographic factors did. The implication is that these domains may provide information of a person’s intelligence level.

  6. Synthesis, Characterization and Battery Performance of A Lithium Poly (4-vinylphenol) Phenolate Borate Composite Membrane

    International Nuclear Information System (INIS)

    Xu, Guodong; Zhang, Yunfeng; Rohan, Rupesh; Cai, Weiwei; Cheng, Hansong

    2014-01-01

    We report synthesis of lithium poly (4-vinylphenol) phenolate borate (LiPVPPB) single-ion conductor comprised of boron atoms with sp 3 electronic configuration covalently bonded to a polystyrene backbone with high thermal and electrochemical stability. The highly delocalized anionic charges surrounding the boron atoms in the polymer give rise to weak association with lithium ions in the polymer matrix, resulting in an ion transference number close to unity and remarkably high ionic conductivity. A composite membrane blended with LiPVPPB and poly(vinylidene-fluoride-co-hexafluoropropene) (PVDF-HFP) was fabricated. The battery of the electrolyte displays excellent cyclability with nearly 100% coulombic efficiency over a wide temperature range. The superior membrane performance suggests that single ion polymer electrolyte materials are highly promising for safe and high power applications of lithium ion batteries

  7. Molecular Spring Enabled High-Performance Anode for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Tianyue Zheng

    2017-11-01

    Full Text Available Flexible butyl interconnection segments are synthetically incorporated into an electronically conductive poly(pyrene methacrylate homopolymer and its copolymer. The insertion of butyl segment makes the pyrene polymer more flexible, and can better accommodate deformation. This new class of flexible and conductive polymers can be used as a polymer binder and adhesive to facilitate the electrochemical performance of a silicon/graphene composite anode material for lithium ion battery application. They act like a “spring” to maintain the electrode mechanical and electrical integrity. High mass loading and high areal capacity, which are critical design requirements of high energy batteries, have been achieved in the electrodes composed of the novel binders and silicon/graphene composite material. A remarkable area capacity of over 5 mAh/cm2 and volumetric capacity of over 1700 Ah/L have been reached at a high current rate of 333 mA/g.

  8. Individual Differences Influencing Immediate Effects of Internal and External Focus Instructions on Children's Motor Performance.

    Science.gov (United States)

    van Abswoude, Femke; Nuijen, Nienke B; van der Kamp, John; Steenbergen, Bert

    2018-06-01

    A large pool of evidence supports the beneficial effect of an external focus of attention on motor skill performance in adults. In children, this effect has been studied less and results are inconclusive. Importantly, individual differences are often not taken into account. We investigated the role of working memory, conscious motor control, and task-specific focus preferences on performance with an internal and external focus of attention in children. Twenty-five children practiced a golf putting task in both an internal focus condition and external focus condition. Performance was defined as the average distance toward the hole in 3 blocks of 10 trials. Task-specific focus preference was determined by asking how much effort it took to apply the instruction in each condition. In addition, working memory capacity and conscious motor control were assessed. Children improved performance in both the internal focus condition and external focus condition (ŋ p 2  = .47), with no difference between conditions (ŋ p 2  = .01). Task-specific focus preference was the only factor moderately related to the difference between performance with an internal focus and performance with an external focus (r = .56), indicating better performance for the preferred instruction in Block 3. Children can benefit from instruction with both an internal and external focus of attention to improve short-term motor performance. Individual, task-specific focus preference influenced the effect of the instructions, with children performing better with their preferred focus. The results highlight that individual differences are a key factor in the effectiveness in children's motor performance. The precise mechanisms underpinning this effect warrant further research.

  9. Impact of different environmental conditions on lithium-ion batteries performance through the thermal monitoring with fiber sensors

    Science.gov (United States)

    Nascimento, Micael; Ferreira, Marta S.; Pinto, João. L.

    2017-08-01

    In this work, an optical fiber sensing network has been developed to assess the impact of different environmental conditions on lithium batteries performance through the real time thermal monitoring. The battery is submitted to constant current charge and different discharge C-rates, under normal and abusive operating conditions. The results show that for the discharge C-rate of 5.77C, the LiB under cold and dry climates had 32.5% and 27.2% lower temperature variations, when compared with temperate climates, respectively. The higher temperature shift detected in the temperate climate was related to the battery better performance regarding discharge capacity and power capabilities.

  10. Performance of African Agricultural Exports and External Market Access Conditions under International Trade Reforms

    OpenAIRE

    Nyangito, Hezron Omare

    2004-01-01

    Sub Saharan African agriculture is currently facing challenges in international trade with respect to external market access conditions and competition in world markets as a result of trade liberalization efforts under the world trade organization (WTO) agreements and in particular the agreement on agriculture (AoA). This paper presents the performance of agricultural exports for selected countries and indicates external market barriers faced and the resulting implications of the barriers on ...

  11. Effects of oral rehydration and external cooling on physiology, perception, and performance in hot, dry climates.

    Science.gov (United States)

    Muñoz, C X; Carney, K R; Schick, M K; Coburn, J W; Becker, A J; Judelson, D A

    2012-12-01

    Only limited research evaluates possible benefits of combined drinking and external cooling (by pouring cold water over the body) during exercise. Therefore, this study examined cold water drinking and external cooling on physiological, perceptual, and performance variables in hot, dry environments. Ten male runners completed four trials of walking 90 min at 30% VO(2max) followed by running a 5-km time trial in 33 ± 1 °C and 30 ± 4% relative humidity. Trials examined no intervention (CON), oral rehydration (OR), external cooling (EC), and oral rehydration plus external cooling (OR + EC). Investigators measured rectal temperature, skin temperatures, heart rate, thirst, thermal sensation, and ratings of perceived exertion (RPE). Oral rehydration (OR and OR + EC) significantly lowered heart rate (P External cooling (EC and OR + EC) significantly reduced chest and thigh temperature (P external cooling (CON and OR) during low-intensity exercise. Performance exhibited no differences (CON = 23.86 ± 4.57 min, OR = 22.74 ± 3.20 min, EC = 22.96 ± 3.11 min, OR + EC = 22.64 ± 3.73 min, P = 0.379). Independent of OR, pouring cold water on the body benefited skin temperature, thermal sensation, and RPE during low-intensity exercise in hot, dry conditions but failed to influence high-intensity performance. © 2012 John Wiley & Sons A/S.

  12. Ultra-light and flexible pencil-trace anode for high performance potassium-ion and lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Zhixin Tai

    2017-07-01

    Full Text Available Engineering design of battery configurations and new battery system development are alternative approaches to achieve high performance batteries. A novel flexible and ultra-light graphite anode is fabricated by simple friction drawing on filter paper with a commercial 8B pencil. Compared with the traditional anode using copper foil as current collector, this innovative current-collector-free design presents capacity improvement of over 200% by reducing the inert weight of the electrode. The as-prepared pencil-trace electrode exhibits excellent rate performance in potassium-ion batteries (KIBs, significantly better than in lithium-ion batteries (LIBs, with capacity retention of 66% for the KIB vs. 28% for the LIB from 0.1 to 0.5 A g−1. It also shows a high reversible capacity of ∼230 mAh g−1 at 0.2 A g−1, 75% capacity retention over 350 cycles at 0.4 A g−1and the highest rate performance (based on the total electrode weight among graphite electrodes for K+ storage reported so far. Keywords: Current-collector-free, Flexible pencil-trace electrode, Potassium-ion battery, Lithium-ion battery, Layer-by-layer interconnected architecture

  13. Performance of a vanadium redox flow battery with tubular cell design

    Science.gov (United States)

    Ressel, Simon; Laube, Armin; Fischer, Simon; Chica, Antonio; Flower, Thomas; Struckmann, Thorsten

    2017-07-01

    We present a vanadium redox flow battery with a tubular cell design which shall lead to a reduction of cell manufacturing costs and the realization of cell stacks with reduced shunt current losses. Charge/discharge cycling and polarization curve measurements are performed to characterize the single test cell performance. A maximum current density of 70 mAcm-2 and power density of 142 Wl-1 (per cell volume) is achieved and Ohmic overpotential is identified as the dominant portion of the total cell overpotential. Cycling displays Coulomb efficiencies of ≈95% and energy efficiencies of ≈55%. During 113 h of operation a stable Ohmic cell resistance is observed.

  14. Al2O3-coated porous separator for enhanced electrochemical performance of lithium sulfur batteries

    International Nuclear Information System (INIS)

    Zhang, Zhiyong; Lai, Yanqing; Zhang, Zhian; Zhang, Kai; Li, Jie

    2014-01-01

    Graphical abstract: Al2O3-coated separator with developed porous channels is prepared by coating Al2O3 polymer solution on routine separator. The batteries with Al2O3-coated separator exhibited a reversible capacity of as high as 593 mAh g-1 at the rate of 0.2 C after 50th charge/discharge cycle. The enhancement in the electrochemical performance could be attributed to the reduced charge transfer resistance after the introduction of Al2O3 coating layer. Besides, the Al2O3 coating layer, acting as a physical barrier for polysulfides, can effectively prevent polysulfides shuttling between the cathode and the anode. We believe that the Al2O3-coated separator is promising in the lithium sulfur battery applications. - Highlights: • Al 2 O 3 -coated separator is used as the separator of lithium sulfur battery. • The cell with Al 2 O 3 -coated separator exhibits excellent cycling stability and high rate capability. • Al 2 O 3 -coated separator is promising in the lithium sulfur battery applications. - Abstract: In this paper, Al 2 O 3 -coated separator with developed porous channels is prepared to improve the electrochemical performance of lithium sulfur batteries. It is demonstrated that the Al 2 O 3 -coating layer is quite effective in reducing shuttle effect and enhancing the stability of the sulfur electrode. The initial discharge capacity of the cell with Al 2 O 3 -coated separator can reach 967 mAh g −1 at the rate of 0.2 C. After 50th charge/discharge cycle, this cell can also deliver a reversible capacity of as high as 593.4 mAh g −1 . Significantly, the charge-transfer resistance of the electrode tends to be reducing after using Al 2 O 3 -coated separator. The improved cell performance is attributed to the porous architecture of the Al 2 O 3 -coating layer, which serves as an ion-conducting skeleton for trapping and depositing dissolved sulfur-containing active materials, as confirmed by scanning electron microscopy (SEM) and energy-dispersive X

  15. Flexible and biocompatible high-performance solid-state micro-battery for implantable orthodontic system

    KAUST Repository

    Kutbee, Arwa T.

    2017-09-25

    To augment the quality of our life, fully compliant personalized advanced health-care electronic system is pivotal. One of the major requirements to implement such systems is a physically flexible high-performance biocompatible energy storage (battery). However, the status-quo options do not match all of these attributes simultaneously and we also lack in an effective integration strategy to integrate them in complex architecture such as orthodontic domain in human body. Here we show, a physically complaint lithium-ion micro-battery (236 μg) with an unprecedented volumetric energy (the ratio of energy to device geometrical size) of 200 mWh/cm3 after 120 cycles of continuous operation. Our results of 90% viability test confirmed the battery’s biocompatibility. We also show seamless integration of the developed battery in an optoelectronic system embedded in a three-dimensional printed smart dental brace. We foresee the resultant orthodontic system as a personalized advanced health-care application, which could serve in faster bone regeneration and enhanced enamel health-care protection and subsequently reducing the overall health-care cost.

  16. Capacity extended bismuth-antimony cathode for high-performance liquid metal battery

    Science.gov (United States)

    Dai, Tao; Zhao, Yue; Ning, Xiao-Hui; Lakshmi Narayan, R.; Li, Ju; Shan, Zhi-wei

    2018-03-01

    Li-Bi based liquid metal batteries (LMBs) have attracted interest due to their potential for solving grid scale energy storage problems. In this study, the feasibility of replacing the bismuth cathode with a bismuth-antimony alloy cathode in lithium based LMBs is investigated. The influence of the Bi:Sb ratio on voltage characteristics is evaluated via the constant current discharge method and electrochemical titration. On observing the cross section of the electrode at various stages of discharge, it is determined that both Sb and Bi form solid intermetallics with Li on the cathode. Additionally, the addition of Bi not only reduces the melting temperature of the Bi:Sb intermetallic but also actively contributes to the electrode capacity. Thereafter, a Li|LiCl-LiF|Sb-Bi liquid metal battery with 3 A h nameplate capacity, assembled and cycled at 1 C rate, is found to possess a stable capacity for over 160 cycles. The overall performance of this battery is discussed in the context of cost effectiveness, energy and coulombic efficiencies.

  17. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Kang [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Wang, Shengping, E-mail: spwang@cug.edu.cn [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China); Zhang, Hanyu; Wu, Jinping [Faculty of Material Science and Chemistry, China University of Geosciences, 388 Lumo Road, 430074 Wuhan (China)

    2013-06-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al{sub 2}O{sub 3} can provide surface area for the deposition of Li{sub 2}S and Li{sub 2}S{sub 2}. ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g{sup −1}, and the remaining capacity was 585 mAh g{sup −1} after 50 cycles at 0.25 mA cm{sup −2}. Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process.

  18. Preparation and electrochemical performance of sulfur-alumina cathode material for lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Dong, Kang; Wang, Shengping; Zhang, Hanyu; Wu, Jinping

    2013-01-01

    Highlights: ► Micron-sized alumina was synthesized as adsorbent for lithium-sulfur batteries. ► Sulfur-alumina material was synthesized via crystallizing nucleation. ► The Al 2 O 3 can provide surface area for the deposition of Li 2 S and Li 2 S 2 . ► The discharge capacity of the battery is improved during the first several cycles. - Abstract: Nano-sized sulfur particles exhibiting good adhesion with conducting acetylene black and alumina composite materials were synthesized by means of an evaporated solvent and a concentrated crystallization method for use as the cathodes of lithium-sulfur batteries. The composites were characterized and examined by X-ray diffraction, environmental scanning electron microscopy and electrochemical methods, such as cyclic voltammetry, electrical impedance spectroscopy and charge–discharge tests. Micron-sized flaky alumina was employed as an adsorbent for the cathode material. The initial discharge capacity of the cathode with the added alumina was 1171 mAh g −1 , and the remaining capacity was 585 mAh g −1 after 50 cycles at 0.25 mA cm −2 . Compared with bare sulfur electrodes, the electrodes containing alumina showed an obviously superior cycle performance, confirming that alumina can contribute to reducing the dissolution of polysulfides into electrolytes during the sulfur charge–discharge process

  19. Design optimization of electric vehicle battery cooling plates for thermal performance

    Science.gov (United States)

    Jarrett, Anthony; Kim, Il Yong

    The performance of high-energy battery cells utilized in electric vehicles (EVs) is greatly improved by adequate temperature control. An efficient thermal management system is also desirable to avoid diverting excessive power from the primary vehicle functions. In a battery cell stack, cooling can be provided by including cooling plates: thin metal fabrications which include one or more internal channels through which a coolant is pumped. Heat is conducted from the battery cells into the cooling plate, and transported away by the coolant. The operating characteristics of the cooling plate are determined in part by the geometry of the channel; its route, width, length, etc. In this study, a serpentine-channel cooling plate is modeled parametrically and its characteristics assessed using computational fluid dynamics (CFD). Objective functions of pressure drop, average temperature, and temperature uniformity are defined and numerical optimization is carried out by allowing the channel width and position to vary. The optimization results indicate that a single design can satisfy both pressure and average temperature objectives, but at the expense of temperature uniformity.

  20. How Does Breadth of External Stakeholder Co-creation Influence Innovation Performance?

    DEFF Research Database (Denmark)

    Markovic, Stefan; Bagherzadeh, Mehdi

    2018-01-01

    . This contradictory empirical evidence highlights the need to unpack this relationship and examine which mediating variables can ensure that co-creating with various types of external stakeholders results in improved innovation performance. Accordingly, this article investigates the impact of breadth of external...... stakeholder co-creation on innovation performance, considering the mediating roles of knowledge sharing and product innovation. The paper draws on a cross-industrial sample of 1516 Spanish firms. Data are analyzed using a set of ordinary-least-squares regression models. Results show that breadth of external...... stakeholder co-creation is not directly related to innovation performance. Instead, this relationship is either fully mediated by product innovation, or follows the path through knowledge sharing and then product innovation....

  1. THE EFFECT OF EXTERN AND INTERN ENVIRONMENT TOWARD BUSINESS STRATEGIES AND THEIR IMPACT TOWARD BUSINESS PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Seo A.Y.

    2018-01-01

    Full Text Available This study was done to see the effect of extern and intern environment toward business strategies and the performance of micro, small and medium enterprises. The population of this study was business owners in Bajawa Regency, Nusa Tenggara Timur Province, Indonesia, represented by 122 respondents as the samples of this study. The samples were chosen using a proportionate stratified random sampling. The data of this study were then analyzed using Partial Least Square technique. The result of this study shows that extern and intern environment have significant effects toward business strategies and performance as mediators.

  2. Recent Progress in the Design of Advanced Cathode Materials and Battery Models for High-Performance Lithium-X (X = O2 , S, Se, Te, I2 , Br2 ) Batteries.

    Science.gov (United States)

    Xu, Jiantie; Ma, Jianmin; Fan, Qinghua; Guo, Shaojun; Dou, Shixue

    2017-07-01

    Recent advances and achievements in emerging Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries with promising cathode materials open up new opportunities for the development of high-performance lithium-ion battery alternatives. In this review, we focus on an overview of recent important progress in the design of advanced cathode materials and battery models for developing high-performance Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries. We start with a brief introduction to explain why Li-X batteries are important for future renewable energy devices. Then, we summarize the existing drawbacks, major progress and emerging challenges in the development of cathode materials for Li-O 2 (S) batteries. In terms of the emerging Li-X (Se, Te, I 2 , Br 2 ) batteries, we systematically summarize their advantages/disadvantages and recent progress. Specifically, we review the electrochemical performance of Li-Se (Te) batteries using carbonate-/ether-based electrolytes, made with different electrode fabrication techniques, and of Li-I 2 (Br 2 ) batteries with various cell designs (e.g., dual electrolyte, all-organic electrolyte, with/without cathode-flow mode, and fuel cell/solar cell integration). Finally, the perspective on and challenges for the development of cathode materials for the promising Li-X (X = O 2 , S, Se, Te, I 2 , Br 2 ) batteries is presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Enhancing the stepped solar still performance using internal and external reflectors

    International Nuclear Information System (INIS)

    Omara, Z.M.; Kabeel, A.E.; Younes, M.M.

    2014-01-01

    Highlights: • Stepped solar still with internal and external reflectors have been investigated. • The productivity of the modified stepped solar still is higher than conventional by 103%. • The productivity of stepped still with external mirror is higher than that for conventional still by 88%. - Abstract: The performance of stepped solar still with internal and external reflectors have been investigated in the current study. The reflectors are used to enhance energy input to the stepped still. The influence of internal and external (top and bottom) reflectors on the performance of the stepped solar still is investigated. A comparison between modified stepped solar still and conventional solar still is carried out to evaluate the developed desalination system performance under the same climate conditions. The results indicated that, during experimentation the productivity of the modified stepped solar still with internal and external (top and bottom) reflectors is higher than that for conventional still approximately by 125%. In this case the estimated cost of 1 l of distillate for stepped still with reflectors and conventional solar stills is approximately 0.031$ and 0.049$, respectively

  4. Performance-degradation model for Li4Ti5O12-based battery cells used in wind power applications

    DEFF Research Database (Denmark)

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina

    2012-01-01

    Energy storage systems based on Lithium-ion batteries have the potential to mitigate the negative impact of wind power grid integration on the power system stability, which is caused by the characteristics of the wind. This paper presents a performance model for a Li4Ti5O12/LiMO2 battery cell....... For developing the performance model an EIS-based electrical modelling approach was followed. The obtained model is able to predict with high accuracy charge and discharge voltage profiles for different ages of the battery cell and for different charging/discharging current rates. Moreover, the ageing behaviour...... of the battery cell was analysed for the case of accelerated cycling ageing with a certain mission profile....

  5. Correlations among structure, composition and electrochemical performances of WO3 anode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Li, Pu; Li, Xing; Zhao, Ziyan; Wang, Mingshan; Fox, Thomas; Zhang, Qian; Zhou, Ying

    2016-01-01

    Highlights: • The residual precursor ions affect the charge/discharge performances of WO 3 . • Lithiated monoclinic WO 3 reveals the best discharge capacity. • Lithiation can enhance the conductivity of WO 3 . - Abstract: Suitable host structure for lithium insertion and extraction is crucial for lithium-ion batteries. Tungsten trioxides (WO 3 ) are particularly interesting materials for this purpose. In this work, the influences of structure and composition of WO 3 on the charge/discharge performances of Li-ion batteries are systematically investigated. Firstly, lithiated tungsten trioxides (Li-WO 3 ) are successfully synthesized by a hydrothermal method followed by annealing at different temperatures (200–600 °C). It is found that the hexagonal framework collapses and gradually transforms to the monoclinic phase due to the release of NH 4 + and NH 3 molecules. Unexpectedly, monoclinic WO 3 reveals better performances than that of hexagonal WO 3 . Among all the investigated samples, the lithiated WO 3 annealed at 500 °C exhibits the highest discharge capacity and cycle performance (703 mAh g −1 after 10 cycles). We believe that the Li + remained in the solid structure of WO 3 can lead to a more stable structure. In addition, Li + could inhibit the oxidation of W 5+ during the heat treatment process, which increases the electron conductivity of WO 3 . Our results indicate that the electrochemical properties of WO 3 are strongly related to the residual precursor and crystal structure.

  6. High Performance Li4Ti5O12/Si Composite Anodes for Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Chunhui Chen

    2015-08-01

    Full Text Available Improving the energy capacity of spinel Li4Ti5O12 (LTO is very important to utilize it as a high-performance Li-ion battery (LIB electrode. In this work, LTO/Si composites with different weight ratios were prepared and tested as anodes. The anodic and cathodic peaks from both LTO and silicon were apparent in the composites, indicating that each component was active upon Li+ insertion and extraction. The composites with higher Si contents (LTO:Si = 35:35 exhibited superior specific capacity (1004 mAh·g−1 at lower current densities (0.22 A·g−1 but the capacity deteriorated at higher current densities. On the other hand, the electrodes with moderate Si contents (LTO:Si = 50:20 were able to deliver stable capacity (100 mAh·g−1 with good cycling performance, even at a very high current density of 7 A·g−1. The improvement in specific capacity and rate performance was a direct result of the synergy between LTO and Si; the former can alleviate the stresses from volumetric changes in Si upon cycling, while Si can add to the capacity of the composite. Therefore, it has been demonstrated that the addition of Si and concentration optimization is an easy yet an effective way to produce high performance LTO-based electrodes for lithium-ion batteries.

  7. VRLA Refined™ lead — A must for VRLA batteries. Specification and Performance

    Science.gov (United States)

    Stevenson, M. W.; Lakshmi, C. S.; Manders, J. E.; Lam, L. T.

    VRLA Refined™ lead produced and marketed by Pasminco since 1997 is a very high purity lead with guaranteed low levels of the gassing elements but with optimum bismuth content that produces oxide of finer particle size, higher acid absorption and imparts outstanding electrical performance and endurance especially under conditions of deep cycling. VRLA batteries suffer dry-out, self-discharge, negative plate capacity loss and poor cycle life unless special lead is used for the grids and active material. This paper addresses the lead used for active material.

  8. Discriminating performance parameters for 50 amp-hour and 60 amp-hour nickel-cadmium plates and battery cells

    Science.gov (United States)

    Toft, Mark R.

    1994-01-01

    This is a follow-up of studies of the NASA standard 50 AH cell presented at the NASA battery workshop each of the last two years. This is a dynamic study. Data trends continue to be developed and analyzed for their utility in judging NiCd performance. The trends and parameters presented here may bear relevance to many designs of conventional NiCd batteries, not just the 50 AH and 60 AH sizes.

  9. Self-assembled MoS2–carbon nanostructures: influence of nanostructuring and carbon on lithium battery performance

    KAUST Repository

    Das, Shyamal K.

    2012-01-01

    Composites of MoS 2 and amorphous carbon are grown and self-assembled into hierarchical nanostructures via a hydrothermal method. Application of the composites as high-energy electrodes for rechargeable lithium-ion batteries is investigated. The critical roles of nanostructuring of MoS 2 and carbon composition on lithium-ion battery performance are highlighted. © 2012 The Royal Society of Chemistry.

  10. Local Electric Field Facilitates High-Performance Li-Ion Batteries.

    Science.gov (United States)

    Liu, Youwen; Zhou, Tengfei; Zheng, Yang; He, Zhihai; Xiao, Chong; Pang, Wei Kong; Tong, Wei; Zou, Youming; Pan, Bicai; Guo, Zaiping; Xie, Yi

    2017-08-22

    By scrutinizing the energy storage process in Li-ion batteries, tuning Li-ion migration behavior by atomic level tailoring will unlock great potential for pursuing higher electrochemical performance. Vacancy, which can effectively modulate the electrical ordering on the nanoscale, even in tiny concentrations, will provide tempting opportunities for manipulating Li-ion migratory behavior. Herein, taking CuGeO 3 as a model, oxygen vacancies obtained by reducing the thickness dimension down to the atomic scale are introduced in this work. As the Li-ion storage progresses, the imbalanced charge distribution emerging around the oxygen vacancies could induce a local built-in electric field, which will accelerate the ions' migration rate by Coulomb forces and thus have benefits for high-rate performance. Furthermore, the thus-obtained CuGeO 3 ultrathin nanosheets (CGOUNs)/graphene van der Waals heterojunctions are used as anodes in Li-ion batteries, which deliver a reversible specific capacity of 1295 mAh g -1 at 100 mA g -1 , with improved rate capability and cycling performance compared to their bulk counterpart. Our findings build a clear connection between the atomic/defect/electronic structure and intrinsic properties for designing high-efficiency electrode materials.

  11. Performance enhancement of iron-chromium redox flow batteries by employing interdigitated flow fields

    Science.gov (United States)

    Zeng, Y. K.; Zhou, X. L.; Zeng, L.; Yan, X. H.; Zhao, T. S.

    2016-09-01

    The catalyst for the negative electrode of iron-chromium redox flow batteries (ICRFBs) is commonly prepared by adding a small amount of Bi3+ ions in the electrolyte and synchronously electrodepositing metallic particles onto the electrode surface at the beginning of charge process. Achieving a uniform catalyst distribution in the porous electrode, which is closely related to the flow field design, is critically important to improve the ICRFB performance. In this work, the effects of flow field designs on catalyst electrodeposition and battery performance are investigated. It is found that compared to the serpentine flow field (SFF) design, the interdigitated flow field (IFF) forces the electrolyte through the porous electrode between the neighboring channels and enhances species transport during the processes of both the catalyst electrodeposition and iron/chromium redox reactions, thus enabling a more uniform catalyst distribution and higher mass transport limitation. It is further demonstrated that the energy efficiency of the ICRFB with the IFF reaches 80.7% at a high current density (320 mA cm-2), which is 8.2% higher than that of the ICRFB with the SFF. With such a high performance and intrinsically low-cost active materials, the ICRFB with the IFF offers a great promise for large-scale energy storage.

  12. Effects of external pressure on the performance and ageing of single-layer lithium-ion pouch cells

    Science.gov (United States)

    Mussa, Abdilbari Shifa; Klett, Matilda; Lindbergh, Göran; Lindström, Rakel Wreland

    2018-05-01

    The effects of external compression on the performance and ageing of NMC(1/3)/Graphite single-layer Li-ion pouch cells are investigated using a spring-loaded fixture. The influence of pressure (0.66, 0.99, 1.32, and 1.98 MPa) on impedance is characterized in fresh cells that are subsequently cycled at the given pressure levels. The aged cells are analyzed for capacity fade and impedance rise at the cell and electrode level. The effect of pressure distribution that may occur in large-format cells or in a battery pack is simulated using parallel connected cells. The results show that the kinetic and mass transport resistance increases with pressure in a fresh cell. An optimum pressure around 1.3 MPa is shown to be beneficial to reduce cyclable-lithium loss during cycling. The minor active mass losses observed in the electrodes are independent of the ageing pressure, whereas ageing pressure affects the charge transfer resistance of both NMC and graphite electrodes and the ohmic resistance of the cell. Pressure distribution induces current distribution but the enhanced current throughput at lower pressures cell does not accelerate its ageing. Conclusions from this work can explain some of the discrepancies in non-uniform ageing reported in the literature and indicate coupling between electrochemistry and mechanics.

  13. Comparison of electrochemical performances of olivine NaFePO4 in sodium-ion batteries and olivine LiFePO4 in lithium-ion batteries.

    Science.gov (United States)

    Zhu, Yujie; Xu, Yunhua; Liu, Yihang; Luo, Chao; Wang, Chunsheng

    2013-01-21

    Carbon-coated olivine NaFePO(4) (C-NaFePO(4)) spherical particles with a uniform diameter of ∼80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO(4) (C-LiFePO(4)), which is synthesized by a solvothermal method. The C-NaFePO(4) electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO(4) except that Li ions in C-LiFePO(4) are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO(4) cathode in sodium-ion (Na-ion) batteries and C-LiFePO(4) in lithium-ion (Li-ion) batteries. In this paper, the equilibrium potentials, reaction resistances, and diffusion coefficient of Na in C-NaFePO(4) are systematically investigated by using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and compared to those of the well-known LiFePO(4) cathodes in Li-ion batteries. Due to the lower diffusion coefficient of Na-ion and higher contact and charge transfer resistances in NaFePO(4) cathodes, the rate performance of C-NaFePO(4) in Na-ion batteries is much worse than that of C-LiFePO(4) in Li-ion batteries. However, the cycling stability of C-NaFePO(4) is almost comparable to C-LiFePO(4) by retaining 90% of its capacity even after 100 charge-discharge cycles at a charge-discharge rate of 0.1 C.

  14. Enhanced performance of Li-O2 battery based on CFx/C composites as cathode materials

    International Nuclear Information System (INIS)

    Wu, Chaolumen; Wang, Haibin; Liao, Chenbo; Yang, Jun; Li, Lei

    2015-01-01

    A hybrid air-electrode composed of a mixture of fluorinated carbon (CF x ) and Ketjen black (KB) active carbon composite materials was prepared to improve performance of Li-O 2 battery. In the hybrid air-electrodes, four kinds of CF x materials including fluorinated graphite, fluorinated carbon fiber, fluorinated coke and fluorinated black carbon were utilized as lithium insertion materials. The physical properties and morphologies of the KB and CF x carbon materials were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM) measurements. Compared with the conventional KB air-electrode, all the CF x /KB hybrid air-electrodes in Li-O 2 batteries showed higher specific discharge capacity, especially at high current density. Among these CF x /KB hybrid air-electrodes, the fluorinated graphite based electrode showed the best electrochemical performance in Li-O 2 battery due to its highest discharge capacity of the fluorinated graphite material in the Li/CF x primary battery, highest specific surface area, and highest total pore volume. The electrochemical performance of Li-O 2 and Li-air batteries using the hybrid air-electrodes with the different fluorinated graphite: KB weight ratio, including specific charge and discharge capacity, cycling stability and rate capability were systematically investigated. At a current density of 0.5 mA cm −2 , the fluorinated graphite based air-electrode delivered a high specific discharge capacity of 1138 mAh g −1 in Li-O 2 batteries, which was more than four times than that of the conventional KB air-electrode (265 mAh g −1 ) under same testing conditions. The battery assembled with the fluorinated graphite based air-electrode exhibited better cycling stability than that of the battery assembled with the conventional KB air-electrode.

  15. Internal and external use of performance information in public organisations: Results from an international executive survey

    NARCIS (Netherlands)

    G. Hammerschmid (Gerhard); S.G.J. Van de Walle (Steven); V. Štimac (Vid)

    2013-01-01

    textabstractAbstract. This paper analyses determinants of public managers´ internal and external use of performance information. Using a sample of over 3100 top public sector executives in six European countries, we find evidence for significant country variations, with a more limited use of

  16. Numerical investigations on the performance of external-cavity mode-locked semiconductor lasers

    DEFF Research Database (Denmark)

    Mulet, Josep; Mørk, Jesper

    2004-01-01

    The performance of an external-cavity mode-locked semiconductor laser is analyzed theoretically and numerically. Passive mode-locking is described using a fully-distributed time-domain model including fast effects, spectral hole burning and carrier heating. We provide optimization rules in order ...

  17. Modeling the Performance and Cost of Lithium-Ion Batteries for Electric-Drive Vehicles - SECOND EDITION

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Paul A. [Argonne National Lab. (ANL), Argonne, IL (United States); Gallagher, Kevin G. [Argonne National Lab. (ANL), Argonne, IL (United States); Bloom, Ira D. [Argonne National Lab. (ANL), Argonne, IL (United States); Dees, Dennis W. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2012-01-01

    This report details the Battery Performance and Cost model (BatPaC) developed at Argonne National Laboratory for lithium-ion battery packs used in automotive transportation. The model designs the battery for a specified power, energy, and type of vehicle battery. The cost of the designed battery is then calculated by accounting for every step in the lithium-ion battery manufacturing process. The assumed annual production level directly affects each process step. The total cost to the original equipment manufacturer calculated by the model includes the materials, manufacturing, and warranty costs for a battery produced in the year 2020 (in 2010 US$). At the time this report is written, this calculation is the only publicly available model that performs a bottom-up lithium-ion battery design and cost calculation. Both the model and the report have been publicly peer-reviewed by battery experts assembled by the U.S. Environmental Protection Agency. This report and accompanying model include changes made in response to the comments received during the peer-review. The purpose of the report is to document the equations and assumptions from which the model has been created. A user of the model will be able to recreate the calculations and perhaps more importantly, understand the driving forces for the results. Instructions for use and an illustration of model results are also presented. Almost every variable in the calculation may be changed by the user to represent a system different from the default values pre-entered into the program. The distinct advantage of using a bottom-up cost and design model is that the entire power-to-energy space may be traversed to examine the correlation between performance and cost. The BatPaC model accounts for the physical limitations of the electrochemical processes within the battery. Thus, unrealistic designs are penalized in energy density and cost, unlike cost models based on linear extrapolations. Additionally, the consequences on

  18. Assessment of patient radiation protection in external radiotherapy departments after inspections performed by the ASN 2008

    International Nuclear Information System (INIS)

    Franchi, Vincent; Marchal, Carole

    2009-10-01

    This report proposes an assessment of patient radiation protection in external radiotherapy. It is based on inter-regional syntheses of inspections performed by the ASN in external radiotherapy departments during 2008. It addresses 6 main themes related to patient radiation protection: human and material resources, organisation of medical physics, training in patient radiation protection, mastering of equipment (maintenance, internal quality controls of medical devices), safety and care quality management (formalization of the patient care process and definition of responsibilities, patient identity control, treatment preparation, and treatment execution), and risk management (a priori risk analysis, declaration, recording and internal processing of dysfunctions, improvements of care quality and safety management system)

  19. Binder-induced surface structure evolution effects on Li-ion battery performance

    Science.gov (United States)

    Rezvani, S. J.; Pasqualini, M.; Witkowska, A.; Gunnella, R.; Birrozzi, A.; Minicucci, M.; Rajantie, H.; Copley, M.; Nobili, F.; Di Cicco, A.

    2018-03-01

    A comparative investigation on binder induced chemical and morphological evolution of Li4Ti5O12 electrodes was performed via X-ray photoemission spectroscopy, scanning electron microscopy, and electrochemical measurements. Composite electrodes were obtained using three different binders (PAA, PVdF, and CMC) with 80:10:10 ratio of active material:carbon:binder. The electrochemical performances of the electrodes, were found to be intimately correlated with the evolution of the microstructure of the electrodes, probed by XPS and SEM analysis. Our analysis shows that the surface chemistry, thickness of the passivation layers and the morphology of the electrodes are strongly dependent on the type of binders that significantly influence the electrochemical properties of the electrodes. These results point to a key role played by binders in optimization of the battery performance and improve our understanding of the previously observed and unexplained electrochemical properties of these electrodes.

  20. Low Cost Metal Carbide Nanocrystals as Binding and Electrocatalytic Sites for High Performance Li-S Batteries.

    Science.gov (United States)

    Zhou, Fei; Li, Zheng; Luo, Xuan; Wu, Tong; Jiang, Bin; Lu, Lei-Lei; Yao, Hong-Bin; Antonietti, Markus; Yu, Shu-Hong

    2018-02-14

    Lithium sulfur (Li-S) batteries are considered as promising energy storage systems for the next generation of batteries due to their high theoretical energy densities and low cost. Much effort has been made to improve the practical energy densities and cycling stability of Li-S batteries via diverse designs of materials nanostructure. However, achieving simultaneously good rate capabilities and stable cycling of Li-S batteries is still challenging. Herein, we propose a strategy to utilize a dual effect of metal carbide nanoparticles decorated on carbon nanofibers (MC NPs-CNFs) to realize high rate performance, low hysteresis, and long cycling stability of Li-S batteries in one system. The adsorption experiments of lithium polysulfides (LiPS) to MC NPs and corresponding theoretical calculations demonstrate that LiPS are likely to be adsorbed and diffused on the surface of MC NPs because of their moderate chemical bonding. MC NPs turn out to have also an electrocatalytic role and accelerate electrochemical redox reactions of LiPS, as proven by cyclic voltammetry analysis. The fabricated Li-S batteries based on the W 2 C NPs-CNFs hybrid electrodes display not only high specific capacity of 1200 mAh/g at 0.2C but also excellent rate performance and cycling stability, for example, a model setup can be operated at 1C for 500 cycles maintaining a final specific capacity of 605 mAh/g with a degradation rate as low as 0.06%/cycle.

  1. Porous Si spheres encapsulated in carbon shells with enhanced anodic performance in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Wu, Ping, E-mail: zjuwuping@njnu.edu.cn; Shi, Huimin; Lou, Feijian; Tang, Yawen; Zhou, Tongge; Zhou, Yiming, E-mail: zhouyiming@njnu.edu.cn; Lu, Tianhong

    2014-07-01

    Highlights: • In situ magnesiothermic reduction route for the formation of porous Si@C spheres. • Unique microstructural characteristics of both porous sphere and carbon matrix. • Enhanced anodic performance in term of cycling stability for lithium-ion batteries. - Abstract: A novel type of porous Si–C micro/nano-hybrids, i.e., porous Si spheres encapsulated in carbon shells (porous Si@C spheres), has been constructed through the pyrolysis of polyvinylidene fluoride (PVDF) and subsequent magnesiothermic reduction methodology by using SiO{sub 2} spheres as precursors. The as-synthesized porous Si@C spheres have been applied as anode materials for lithium-ion batteries (LIBs), and exhibit enhanced anodic performance in term of cycling stability compared with bare Si spheres. For example, the porous Si@C spheres are able to exhibit a high reversible capacity of 900.0 mA h g{sup −1} after 20 cycles at a current density of 0.05 C (1 C = 4200 mA g{sup −1}), which is much higher than that of bare Si spheres (430.7 mA h g{sup −1})

  2. CoS/CNTs hybrid structure for improved performance lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huijun; Ma, Jingjing; Liu, Sheng; Nie, Longying; Chai, Yaqin; Yang, Xia, E-mail: xiayang2@swu.edu.cn; Yuan, Ruo, E-mail: yuanruo@swu.edu.cn

    2016-08-15

    Cobalt sulfide (CoS) has a high theoretical capacity as an anode materials for lithium ion batteries (LIBs), however it suffers from poor cyclability and weak retention. Therefore, a lot of efforts have been devoted to overcome these defects. In this work, cobalt sulfide/carbon nanotubes (CoS/CNTs) nanocomposites were prepared by a simple and effective solvothermal method. The nanocomposites were constructed by CoS nanoparticles coated on the carbon nanotubes and the electrochemical performances of the CoS/CNTs nanocomposites were investigated as anode materials for LIBs. The results showed that the materials had superior cycle stability and kept a high discharge capacity of 780 mAh g{sup −1} after 50 cycles at the current density of 100 mA g{sup −1}. The excellent electrochemical performances are due to the good combination of the hybrid structure and better electron transportation originated from CNTs. The CoS/CNTs nanocomposites with excellent rate capabilities and super capabilities could be promising anode material for lithium ion battery. - Highlights: • CoS/CNTs nanocomposites were prepared by a simple and effective solvothermal method. • Compared with pristine CoS, CoS/CNTs nanocomposites had superior cycle stability. • CoS/CNTs nanocomposites kept a high discharge capacity of 780 mAh g{sup −1} after 50 cycles at 100 mA g{sup −1}.

  3. High Performance Hydrogen/Bromine Redox Flow Battery for Grid-Scale Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Cho, KT; Ridgway, P; Weber, AZ; Haussener, S; Battaglia, V; Srinivasan, V

    2012-01-01

    The electrochemical behavior of a promising hydrogen/bromine redox flow battery is investigated for grid-scale energy-storage application with some of the best redox-flow-battery performance results to date, including a peak power of 1.4 W/cm(2) and a 91% voltaic efficiency at 0.4 W/cm(2) constant-power operation. The kinetics of bromine on various materials is discussed, with both rotating-disk-electrode and cell studies demonstrating that a carbon porous electrode for the bromine reaction can conduct platinum-comparable performance as long as sufficient surface area is realized. The effect of flow-cell designs and operating temperature is examined, and ohmic and mass-transfer losses are decreased by utilizing a flow-through electrode design and increasing cell temperature. Charge/discharge and discharge-rate tests also reveal that this system has highly reversible behavior and good rate capability. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.018211jes] All rights reserved.

  4. Next Generation Anodes for Lithium Ion Batteries: Thermodynamic Understanding and Abuse Performance.

    Energy Technology Data Exchange (ETDEWEB)

    Fenton, Kyle R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nagasubramanian, Ganesan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-01-01

    As we develop new materials to increase performance of lithium ion batteries for electric vehicles, the impact of potential safety and reliability issues become increasingly important. In addition to electrochemical performance increases (capacity, energy, cycle life, etc.), there are a variety of materials advancements that can be made to improve lithium-ion battery safety. Issues including energetic thermal runaway, electrolyte decomposition and flammability, anode SEI stability, and cell-level abuse tolerance behavior. Introduction of a next generation materials, such as silicon based anode, requires a full understanding of the abuse response and degradation mechanisms for these anodes. This work aims to understand the breakdown of these materials during abuse conditions in order to develop an inherently safe power source for our next generation electric vehicles. The effect of materials level changes (electrolytes, additives, silicon particle size, silicon loading, etc.) to cell level abuse response and runaway reactions will be determined using several techniques. Experimentation will start with base material evaluations in coin cells and overall runaway energy will be evaluated using techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and accelerating rate calorimetry (ARC). The goal is to understand the effect of materials parameters on the runaway reactions, which can then be correlated to the response seen on larger cells (18650). Experiments conducted showed that there was significant response from these electrodes. Efforts to minimize risk during testing were taken by development of a smaller capacity cylindrical design in order to quantify materials decision and how they manifest during abuse response.

  5. CuO nanorods/graphene nanocomposites for high-performance lithium-ion battery anodes

    International Nuclear Information System (INIS)

    Wang, Qi; Zhao, Jun; Shan, Wanfei; Xia, Xinbei; Xing, Lili; Xue, Xinyu

    2014-01-01

    Highlights: • CuO/GNS nanocomposites are synthesized by a hydrothermal method. • CuO/GNSs as LIB anodes exhibit much higher cyclability and capacity than CuO nanostructures. • Such excellent performances can be attributed to the synergistic effect between CuO and GNSs. -- Abstract: CuO/graphene nanocomposites are synthesized by a hydrothermal method, and their application as anodes of lithium-ion batteries has been investigated. CuO nanorods are uniformly coating on the surface of graphene nanosheets. CuO/graphene nanocomposites exhibit high cyclability and capacity. After 50 cycles, the capacity can maintain at 692.5 mA h g −1 at 0.1 C rate (10 h per half cycle). Such a high performance can be attributed to the synergistic effect between graphene nanosheets and CuO nanorods. The present results indicate that CuO/graphene nanocomposites have potential applications in the anodes of lithium-ion battery

  6. Synthesis of manganese coordination polymer microspheres for lithium-ion batteries with good cycling performance

    International Nuclear Information System (INIS)

    Fei, Hailong; Liu, Xin; Li, Zhiwei; Feng, Wenjing

    2015-01-01

    Highlights: • We achieve controllable synthesis of manganese 2,5-thiophene dicarboxylate microspheres with DMF and CTABr. • We perform research on changes in morphologies and crystalline structure. • It is a new anode material for lithium-ion batteries with high capacity and good cycle stability. - Abstract: A simple and versatile method for preparation of novel manganese 2,5-thiophene dicarboxylate microspheres is developed via a surfactant-assisted solvo-thermal route, which are found to be a new high-energy anode material for lithium-ion batteries. It shows better cycling performance and higher discharge capacity than its counterpart of irregular shapes. A reversible capacity was achieved as high as 645.7 mA h g −1 after 250 cycles at a current density of 400 mA g −1 . Furthermore, the coulombic efficiency can be close to 100% even after 650 charge-discharge cycles at a current density of 500 mA g −1

  7. Porous Si spheres encapsulated in carbon shells with enhanced anodic performance in lithium-ion batteries

    International Nuclear Information System (INIS)

    Wang, Hui; Wu, Ping; Shi, Huimin; Lou, Feijian; Tang, Yawen; Zhou, Tongge; Zhou, Yiming; Lu, Tianhong

    2014-01-01

    Highlights: • In situ magnesiothermic reduction route for the formation of porous Si@C spheres. • Unique microstructural characteristics of both porous sphere and carbon matrix. • Enhanced anodic performance in term of cycling stability for lithium-ion batteries. - Abstract: A novel type of porous Si–C micro/nano-hybrids, i.e., porous Si spheres encapsulated in carbon shells (porous Si@C spheres), has been constructed through the pyrolysis of polyvinylidene fluoride (PVDF) and subsequent magnesiothermic reduction methodology by using SiO 2 spheres as precursors. The as-synthesized porous Si@C spheres have been applied as anode materials for lithium-ion batteries (LIBs), and exhibit enhanced anodic performance in term of cycling stability compared with bare Si spheres. For example, the porous Si@C spheres are able to exhibit a high reversible capacity of 900.0 mA h g −1 after 20 cycles at a current density of 0.05 C (1 C = 4200 mA g −1 ), which is much higher than that of bare Si spheres (430.7 mA h g −1 )

  8. Scalable 2D Mesoporous Silicon Nanosheets for High-Performance Lithium-Ion Battery Anode.

    Science.gov (United States)

    Chen, Song; Chen, Zhuo; Xu, Xingyan; Cao, Chuanbao; Xia, Min; Luo, Yunjun

    2018-03-01

    Constructing unique mesoporous 2D Si nanostructures to shorten the lithium-ion diffusion pathway, facilitate interfacial charge transfer, and enlarge the electrode-electrolyte interface offers exciting opportunities in future high-performance lithium-ion batteries. However, simultaneous realization of 2D and mesoporous structures for Si material is quite difficult due to its non-van der Waals structure. Here, the coexistence of both mesoporous and 2D ultrathin nanosheets in the Si anodes and considerably high surface area (381.6 m 2 g -1 ) are successfully achieved by a scalable and cost-efficient method. After being encapsulated with the homogeneous carbon layer, the Si/C nanocomposite anodes achieve outstanding reversible capacity, high cycle stability, and excellent rate capability. In particular, the reversible capacity reaches 1072.2 mA h g -1 at 4 A g -1 even after 500 cycles. The obvious enhancements can be attributed to the synergistic effect between the unique 2D mesoporous nanostructure and carbon capsulation. Furthermore, full-cell evaluations indicate that the unique Si/C nanostructures have a great potential in the next-generation lithium-ion battery. These findings not only greatly improve the electrochemical performances of Si anode, but also shine some light on designing the unique nanomaterials for various energy devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Sulfur nanocrystals anchored graphene composite with highly improved electrochemical performance for lithium-sulfur batteries

    Science.gov (United States)

    Zhang, Jun; Dong, Zimin; Wang, Xiuli; Zhao, Xuyang; Tu, Jiangping; Su, Qingmei; Du, Gaohui

    2014-12-01

    Two kinds of graphene-sulfur composites with 50 wt% of sulfur are prepared using hydrothermal method and thermal mixing, respectively. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectra mapping show that sulfur nanocrystals with size of ∼5 nm dispersed on graphene sheets homogeneously for the sample prepared by hydrothermal method (NanoS@G). While for the thermal mixed graphene-sulfur composite (S-G mixture), sulfur shows larger and uneven size (50-200 nm). X-ray Photoelectron Spectra (XPS) reveals the strong chemical bonding between the sulfur nanocrystals and graphene. Comparing with the S-G mixture, the NanoS@G composite shows highly improved electrochemical performance as cathode for lithium-sulfur (Li-S) battery. The NanoS@G composite delivers an initial capacity of 1400 mAh g-1 with the sulfur utilization of 83.7% at a current density of 335 mA g-1. The capacity keeps above 720 mAh g-1 over 100 cycles. The strong adherence of the sulfur nanocrystals on graphene immobilizes sulfur and polysulfides species and suppressed the "shuttle effect", resulting higher coulombic efficiency and better capacity retention. Electrochemical impedance also suggests that the strong bonding enabled rapid electronic/ionic transport and improved electrochemical kinetics, therefore good rate capability is obtained. These results demonstrate that the NanoS@G composite is a very promising candidate for high-performance Li-S batteries.

  10. Effects of operating temperature on the performance of vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Zhang, C.; Zhao, T.S.; Xu, Q.; An, L.; Zhao, G.

    2015-01-01

    Highlights: • The effect of the operating temperature on the VRFB’s performance is studied. • The voltage efficiency and peak power density increases with temperature. • High temperatures aggravate the coulombic efficiency drop and the capacity decay. • The outcomes suggest that thermal management of operating VRFBs is essential. - Abstract: For an operating flow battery system, how the battery’s performance varies with ambient temperatures is of practical interest. To gain an understanding of the general thermal behavior of vanadium redox flow batteries (VRFBs), we devised and tested a laboratory-scale single VRFB by varying the operating temperature. The voltage efficiency of the VRFB is found to increase from 86.5% to 90.5% at 40 mA/cm 2 when the operating temperature is increased from 15 °C to 55 °C. The peak discharge power density is also observed to increase from 259.5 mW/cm 2 to 349.8 mW/cm 2 at the same temperature increment. The temperature increase, however, leads to a slight decrease in the coulombic efficiency from 96.2% to 93.7% at the same temperature increments. In addition, the capacity degradation rate is found to be higher at higher temperatures

  11. Internal and external market orientation as organizational resources - consequences for market and financial performance

    OpenAIRE

    Boris Snoj; Vladimir Gabrijan; Borut Milfelner

    2010-01-01

    The concept of internal marketing has been discussed in marketing literature for over 30 years. Despite this fact there is little theoretical and empirical evidence of the way in which the internal market orientation impacts market and financial performance. On the other hand, there is considerable empirical evidence concerning the impact of the external market orientation on market and financial performance. Consequently, very few research projects have dealt with the impact of both market o...

  12. Accounting for External Turbulence of Logistics Organizations via Performance Measurement Systems

    DEFF Research Database (Denmark)

    Bühler, Andreas; Wallenburg, Carl Marcus; Wieland, Andreas

    2016-01-01

    Purpose: This paper aims to investigate the role of upper management in designing performance measurement systems (PMS) that account for external turbulence of the organization and to show how this PMS design for turbulence impacts organizational resilience and distribution service performance....... Design/methodology/approach: Hypotheses are developed by integrating management accounting and strategic management perspectives into supply chain management and subsequently tested based on data from 431 logistics organizations (i.e. both logistics companies and internal logistics departments...

  13. The Effects of Task Demand and External Stimuli on Learner's Stress Perception and Performance

    OpenAIRE

    Lim, Yee Mei; Ayesh, Aladdin, 1972-; Stacey, Martin; Tan, Li Peng

    2016-01-01

    Over the past decades, research in e-learning has begun to take emotions into account, which is also known as affective learning. It advocates an education system that is sentient of learner's cognitive and affective states, as learners' performance could be affected by emotional factors. This exploratory research examines the impacts of task demand and external stimuli on learner's stress perception and job performance. Experiments are conducted on 160 undergraduate students from a higher le...

  14. SSTI- Lewis Spacecraft Nickel-Hydrogen Battery

    Science.gov (United States)

    Tobias, R. F.

    1997-01-01

    Topics considered include: NASA-Small Spacecraft Technology Initiative (SSTI) objectives, SSTI-Lewis overview, battery requirement, two cells Common Pressure Vessel (CPV) design summary, CPV electric performance, battery design summary, battery functional description, battery performance.

  15. Hierarchical silicon nanowires-carbon textiles matrix as a binder-free anode for high-performance advanced lithium-ion batteries

    Science.gov (United States)

    Liu, Bin; Wang, Xianfu; Chen, Haitian; Wang, Zhuoran; Chen, Di; Cheng, Yi-Bing; Zhou, Chongwu; Shen, Guozhen

    2013-01-01

    Toward the increasing demands of portable energy storage and electric vehicle applications, the widely used graphite anodes with significant drawbacks become more and more unsuitable. Herein, we report a novel scaffold of hierarchical silicon nanowires-carbon textiles anodes fabricated via a facile method. Further, complete lithium-ion batteries based on Si and commercial LiCoO2 materials were assembled to investigate their corresponding across-the-aboard performances, demonstrating their enhanced specific capacity (2950 mAh g−1 at 0.2 C), good repeatability/rate capability (even >900 mAh g−1 at high rate of 5 C), long cycling life, and excellent stability in various external conditions (curvature, temperature, and humidity). Above results light the way to principally replacing graphite anodes with silicon-based electrodes which was confirmed to have better comprehensive performances. PMID:23572030

  16. Interfacial Reaction Dependent Performance of Hollow Carbon Nanosphere – Sulfur Composite as a Cathode for Li-S Battery

    International Nuclear Information System (INIS)

    Zheng, Jianming; Yan, Pengfei; Gu, Meng; Wagner, Michael J.; Hays, Kevin A.; Chen, Junzheng; Li, Xiaohong; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie

    2015-01-01

    Lithium-sulfur (Li-S) battery is a promising energy storage system due to its high energy density, cost effectiveness, and environmental friendliness of sulfur. However, there are still a number of technical challenges, such as low Coulombic efficiency and poor long-term cycle life, impeding the commercialization of Li-S battery. The electrochemical performance of Li-S battery is closely related with the interfacial reactions occurring between hosting substrate and active sulfur species, which are poorly conducting at fully oxidized and reduced states. Here, we correlate the relationship between the performance and interfacial reactions in the Li-S battery system, using a hollow carbon nanosphere (HCNS) with highly graphitic character as hosting substrate for sulfur. With an appropriate amount of sulfur loading, HCNS/S composite exhibits excellent electrochemical performance because of the fast interfacial reactions between HCNS and the polysulfides. However, further increase of sulfur loading leads to increased formation of highly resistive insoluble reaction products (Li 2 S 2 /Li 2 S), which limits the reversibility of the interfacial reactions and results in poor electrochemical performances. These findings demonstrate the importance of the interfacial reaction reversibility in the whole electrode system on achieving high capacity and long cycle life of sulfur cathode for Li-S batteries.

  17. Interfacial Reaction Dependent Performance of Hollow Carbon Nanosphere – Sulfur Composite as a Cathode for Li-S Battery

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Gu, Meng [Pacific Northwest National Laboratory, Richland, WA (United States); Wagner, Michael J.; Hays, Kevin A. [The George Washington University, Washington, DC (United States); Chen, Junzheng; Li, Xiaohong; Wang, Chongmin; Zhang, Ji-Guang; Liu, Jun; Xiao, Jie, E-mail: jie.xiao@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA (United States)

    2015-05-26

    Lithium-sulfur (Li-S) battery is a promising energy storage system due to its high energy density, cost effectiveness, and environmental friendliness of sulfur. However, there are still a number of technical challenges, such as low Coulombic efficiency and poor long-term cycle life, impeding the commercialization of Li-S battery. The electrochemical performance of Li-S battery is closely related with the interfacial reactions occurring between hosting substrate and active sulfur species, which are poorly conducting at fully oxidized and reduced states. Here, we correlate the relationship between the performance and interfacial reactions in the Li-S battery system, using a hollow carbon nanosphere (HCNS) with highly graphitic character as hosting substrate for sulfur. With an appropriate amount of sulfur loading, HCNS/S composite exhibits excellent electrochemical performance because of the fast interfacial reactions between HCNS and the polysulfides. However, further increase of sulfur loading leads to increased formation of highly resistive insoluble reaction products (Li{sub 2}S{sub 2}/Li{sub 2}S), which limits the reversibility of the interfacial reactions and results in poor electrochemical performances. These findings demonstrate the importance of the interfacial reaction reversibility in the whole electrode system on achieving high capacity and long cycle life of sulfur cathode for Li-S batteries.

  18. Internal and external environmental factors affecting the performance of hospital-based home nursing care.

    Science.gov (United States)

    Noh, J-W; Kwon, Y-D; Yoon, S-J; Hwang, J-I

    2011-06-01

    Numerous studies on HNC services have been carried out by signifying their needs, efficiency and effectiveness. However, no study has ever been performed to determine the critical factors associated with HNC's positive results despite the deluge of positive studies on the service. This study included all of the 89 training hospitals that were practising HNC service in Korea as of November 2006. The input factors affecting the performance were classified as either internal or external environmental factors. This analysis was conducted to understand the impact that the corresponding factors had on performance. Data were analysed by using multiple linear regressions. The internal and external environment variables affected the performance of HNC based on univariate analysis. The meaningful variables were internal environmental factors. Specifically, managerial resource (the number of operating beds and the outpatient/inpatient ratio) were meaningful when the multiple linear regression analysis was performed. Indeed, the importance of organizational culture (the passion of HNC nurses) was significant. This study, considering the limited market size of Korea, illustrates that the critical factor for the development of hospital-led HNC lies with internal environmental factors rather than external ones. Among the internal environmental factors, the hospitals' managerial resource-related factors (specifically, the passion of nurses) were the most important contributing element. © 2011 The Authors. International Nursing Review © 2011 International Council of Nurses.

  19. Cyclic performance tests of Sn/MWCNT composite lithium ion battery anodes at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Tocoglu, U., E-mail: utocoglu@sakarya.edu.tr; Cevher, O.; Akbulut, H. [Sakarya University, Engineering Faculty, Department of Metallurgical and Materials Engineering, Esentepe Campus 54187 (Turkey)

    2016-04-21

    In this study tin-multi walled carbon nanotube (Sn-MWCNT) lithium ion battery anodes were produced and their electrochemical galvanostatic charge/discharge tests were conducted at various (25 °C, 35 °C, 50 °C) temperatures to determine the cyclic behaviors of anode at different temperatures. Anodes were produced via vacuum filtration and DC magnetron sputtering technique. Tin was sputtered onto buckypapers to form composite structure of anodes. SEM analysis was conducted to determine morphology of buckypapers and Sn-MWCNT composite anodes. Structural and phase analyses were conducted via X-ray diffraction and Raman Spectroscopy technique. CR2016 coin cells were assembled for electrochemical tests. Cyclic voltammetry test were carried out to determine the reversibility of reactions between anodes and reference electrode between 0.01-2.0 V potential window. Galvanostatic charge/discharge tests were performed to determine cycle performance of anodes at different temperatures.

  20. Enhancing the stability and performance of a battery cathode using a non-aqueous electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Yeol [Division of Engineering, Brown University, Providence, RI 02912 (United States); Sen, Sujat [Department of Chemistry, Brown University, Providence, RI 02912 (United States); Song, Hyun-Kon [Interdisciplinary School of Green Energy and School of Nano-Biotechnology and Chemical Engineering, Ulsan National Institute of Science and Technology, Banyeon-ri 100, Ulju-gun, Ulsan 689-798 (Korea); Palmore, G. Tayhas R. [Division of Biology and Medicine, Brown University, Providence, RI 02912 (United States)

    2010-06-15

    For conductive polymers to be considered materials for energy storage, both their electroactivity and stability must be optimized. In this study, a non-aqueous electrolyte (0.2 M LiClO{sub 4} in acetonitrile) was studied for its effect on the charge storage capacity and stability of two materials used in batteries developed in our laboratory, polypyrrole (pPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) doped with 2,2'-azino-bis(3-ethylbenzothiaxoline-6-sulfonic acid (ABTS)). The results are compared to the performance of these materials in an aqueous electrolyte (0.2 M HCl/aq). Loss of ABTS dopant was eliminated principally due to the low solubility of ABTS in acetonitrile, resulting in cathode materials with improved stability in terms of load cycling and performance. (author)

  1. Electrochemical modeling and performance evaluation of a new ammonia-based battery thermal management system for electric and hybrid electric vehicles

    International Nuclear Information System (INIS)

    Al-Zareer, Maan; Dincer, Ibrahim; Rosen, Marc A.

    2017-01-01

    The operating temperatures of lithium ion battery packs in electrical vehicles and hybrid electrical vehicles need to be maintained in an optimum range for better performance and longer battery life. This paper proposes a new battery pack cooling system that utilizes the low saturation temperature of the fuel in ammonia based future hybrid electric vehicles. In the proposed cooling system, the batteries are partially submerged in to the liquid ammonia, and the liquid ammonia cools the battery by absorbing the heat and evaporating and the ammonia vapor cools the part of the battery not covered by liquid ammonia. The relationships between the performance of the battery cooling system and the maximum temperature (and the temperature distribution) in the battery are investigated for practical applications. The effect of the length of the battery that is submerged in to the liquid ammonia on the thermal performance of battery is studied and evaluated. The present results show that the proposed ammonia based cooling system offers a unique opportunity to maintain the operating temperature of the battery in an optimum range for consecutive charging and discharging phases at a high rate of 7.5C.

  2. The effect of internal and external focus of attention on game performance in tennis

    Directory of Open Access Journals (Sweden)

    Marina Tsetseli

    2016-12-01

    Full Text Available Background: Great importance has been given in recent years to the impact of focus of attention cues during skills execution but not during real game play, where more cognitive skills are involved besides technical performance. Objective: The purpose of the present study was to examine the effect of internal and external focus of attention instructions on the components of the game performance (decision making, skill execution, base in tennis. Methods: The participants (N = 60 were divided into three groups and followed an intervention training program that lasted 6 weeks; IF group (n = 20 under internal focus of attention instructions, EF group (n = 20 under external focus of attention instructions and CON group (n = 20 under no attentional focus instructions. Three measurements took place (pre, post and ret in which the participants were recorded on video while playing matches in real scoring conditions. Game Performance Assessment Instrument (GPAI was used to evaluate the components of game performance in tennis in three game situations; service, return of the service, base line game. Results: ANOVA repeated measures in a 3 (groups: IF, EF & CON × 3 (measurements: pre, post, ret revealed a significant interaction between groups and measurements and post hoc analysis indicated that the group that was instructed to focus externally improved significantly only in decision making compared to the internal focus of attention and to the control group. The score difference was maintained at the retention test as well, which indicates that the impact concerned not only performance but also learning. Conclusions: Instructions that aim to an external focus of attention enhance decision making skills, which are considered the most important element of game performance in tennis.

  3. A novel thermal management system for improving discharge/charge performance of Li-ion battery packs under abuse

    Science.gov (United States)

    Arora, Shashank; Kapoor, Ajay; Shen, Weixiang

    2018-02-01

    Parasitic load, which describes electrical energy consumed by battery thermal management system (TMS), is an important design criterion for battery packs. Passive TMSs using phase change materials (PCMs) are thus generating much interest. However, PCMs suffer from low thermal conductivities. Most current thermal conductivity enhancement techniques involve addition of foreign particles to PCMs. Adding foreign particles increases effective thermal conductivity of PCM-systems but at expense of their latent heat capacity. This paper presents an alternate approach for improving thermal performance of PCM-based TMSs. The introduced technique involves placing battery cells in a vertically inverted position within the battery-pack. It is demonstrated through experiments that inverted cell-layout facilitates build-up of convection current in the pack, which in turn minimises thermal variations within the PCM matrix by enabling PCM mass transfer between the top and the bottom regions of the battery pack. The proposed system is found capable of maintaining tight control over battery cell temperature even during abusive usage, defined as high-rate repetitive cycling with minimal rest periods. In addition, this novel TMS can recover waste heat from PCM-matrix through thermoelectric devices, thereby resulting in a negative parasitic load for TMS.

  4. Organic hydrogen peroxide-driven low charge potentials for high-performance lithium-oxygen batteries with carbon cathodes

    Science.gov (United States)

    Wu, Shichao; Qiao, Yu; Yang, Sixie; Ishida, Masayoshi; He, Ping; Zhou, Haoshen

    2017-06-01

    Reducing the high charge potential is a crucial concern in advancing the performance of lithium-oxygen batteries. Here, for water-containing lithium-oxygen batteries with lithium hydroxide products, we find that a hydrogen peroxide aqueous solution added in the electrolyte can effectively promote the decomposition of lithium hydroxide compounds at the ultralow charge potential on a catalyst-free Ketjen Black-based cathode. Furthermore, for non-aqueous lithium-oxygen batteries with lithium peroxide products, we introduce a urea hydrogen peroxide, chelating hydrogen peroxide without any water in the organic, as an electrolyte additive in lithium-oxygen batteries with a lithium metal anode and succeed in the realization of the low charge potential of ~3.26 V, which is among the best levels reported. In addition, the undesired water generally accompanying hydrogen peroxide solutions is circumvented to protect the lithium metal anode and ensure good battery cycling stability. Our results should provide illuminating insights into approaches to enhancing lithium-oxygen batteries.

  5. Effects of Ni particle morphology on cell performance of Na/NiCl2 battery

    Science.gov (United States)

    Kim, Mangi; Ahn, Cheol-Woo; Hahn, Byung-Dong; Jung, Keeyoung; Park, Yoon-Cheol; Cho, Nam-ung; Lee, Heesoo; Choi, Joon-Hwan

    2017-11-01

    Electrochemical reaction of Ni particle, one of active cathode materials in the Na/NiCl2 battery, occurs on the particle surface. The NiCl2 layer formed on the Ni particle surface during charging can disconnect the electron conduction path through Ni particles because the NiCl2 layer has very low conductivity. The morphology and size of Ni particles, therefore, need to be controlled to obtain high charge capacity and excellent cyclic retention. Effects of the Ni particle size on the cell performance were investigated using spherical Ni particles with diameters of 0.5 μm, 6 μm, and 50 μm. The charge capacities of the cells with spherical Ni particles increased when the Ni particle size becomes smaller because of their higher surface area but their charge capacities were significantly decreased with increasing cyclic tests owing to the disconnection of electron conduction path. The inferior cyclic retention of charge capacity was improved using reticular Ni particles which maintained the reliable connection for the electron conduction in the Na/NiCl2 battery. The charge capacity of the cell with the reticular Ni particles was higher than the cell with the small-sized spherical Ni particles approximately by 26% at 30th cycle.

  6. Nanoparticle-coated separators for lithium-ion batteries with advanced electrochemical performance

    KAUST Repository

    Fang, Jason; Kelarakis, Antonios; Lin, Yueh-Wei; Kang, Chi-Yun; Yang, Ming-Huan; Cheng, Cheng-Liang; Wang, Yue; Giannelis, Emmanuel P.; Tsai, Li-Duan

    2011-01-01

    We report a simple, scalable approach to improve the interfacial characteristics and, thereby, the performance of commonly used polyolefin based battery separators. The nanoparticle-coated separators are synthesized by first plasma treating the membrane in oxygen to create surface anchoring groups followed by immersion into a dispersion of positively charged SiO 2 nanoparticles. The process leads to nanoparticles electrostatically adsorbed not only onto the exterior of the surface but also inside the pores of the membrane. The thickness and depth of the coatings can be fine-tuned by controlling the ζ-potential of the nanoparticles. The membranes show improved wetting to common battery electrolytes such as propylene carbonate. Cells based on the nanoparticle-coated membranes are operable even in a simple mixture of EC/PC. In contrast, an identical cell based on the pristine, untreated membrane fails to be charged even after addition of a surfactant to improve electrolyte wetting. When evaluated in a Li-ion cell using an EC/PC/DEC/VC electrolyte mixture, the nanoparticle-coated separator retains 92% of its charge capacity after 100 cycles compared to 80 and 77% for the plasma only treated and pristine membrane, respectively. © the Owner Societies 2011.

  7. Developing porous carbon with dihydrogen phosphate groups as sulfur host for high performance lithium sulfur batteries

    Science.gov (United States)

    Cui, Yanhui; Zhang, Qi; Wu, Junwei; Liang, Xiao; Baker, Andrew P.; Qu, Deyang; Zhang, Hui; Zhang, Huayu; Zhang, Xinhe

    2018-02-01

    Carbon matrix (CM) derived from biomass is low cost and easily mass produced, showing great potential as sulfur host for lithium sulfur batteries. In this paper we report on a dihydrogen phosphate modified CM (PCM-650) prepared from luffa sponge (luffa acutangula) by phosphoric acid treatment. The phosphoric acid not only increases the surface area of the PCM-650, but also introduces dihydrogen phosphate onto PCM-650 (2.28 at% P). Sulfur impregnated (63.6 wt%) PCM-650/S, in comparison with samples with less dihydrogen phosphate LPCM-650/S, shows a significant performance improvement. XPS analysis is conducted for sulfur at different stages, including sulfur (undischarged), polysulfides (discharge to 2.1 V) and short chain sulfides (discharge to 1.7 V). The results consistently show chemical shifts for S2p in PCM-650, suggesting an enhanced adsorption effect. Furthermore, density functional theory (DFT) calculations is used to clarify the molecular binding: carbon/sulfur (0.86 eV), carbon/Li2S (0.3 eV), CH3-O-PO3H2/sulfur (1.24 eV), and CH3-O-PO3H2/Li2S (1.81 eV). It shows that dihydrogen phosphate group can significantly enhance the binding with sulfur and sulfide, consistent with XPS results. Consequently a CM functionalised with dihydrogen phosphate shows great potential as the sulfur host in a Li-S battery.

  8. Performance and stability of a liquid anode high-temperature metal-air battery

    Science.gov (United States)

    Otaegui, L.; Rodriguez-Martinez, L. M.; Wang, L.; Laresgoiti, A.; Tsukamoto, H.; Han, M. H.; Tsai, C.-L.; Laresgoiti, I.; López, C. M.; Rojo, T.

    2014-02-01

    A High-Temperature Metal-Air Battery (HTMAB) that operates based on a simple redox reaction between molten metal and atmospheric oxygen at 600-1000 °C is presented. This innovative HTMAB concept combines the technology of conventional metal-air batteries with that of solid oxide fuel cells to provide a high energy density system for many applications. Electrochemical reversibility is demonstrated with 95% coulomb efficiency. Cell sealing has been identified as a key issue in order to determine the end-of-charge voltage, enhance coulomb efficiency and ensure long term stability. In this work, molten Sn is selected as anode material. Low utilization of the stored material due to precipitation of the SnO2 on the electrochemically active area limits the expected capacity, which should theoretically approach 903 mAh g-1. Nevertheless, more than 1000 charge/discharge cycles are performed during more than 1000 h at 800 °C, showing highly promising results of stability, reversibility and cyclability.

  9. Design construction and analysis of solar ridge concentrator photovoltaic (PV) system to improve battery charging performance.

    Science.gov (United States)

    Narasimman, Kalaiselvan; Selvarasan, Iniyan

    2016-05-01

    A ridge concentrator photovoltaic system for a 10W multi-crystalline solar panel was designed with the concentration ratios of 1X and 2X. The ray tracing model of ridge concentrator photovoltaic system was carried out using Trace-Pro simulation. The optimum tilt angle for the concentrator PV system throughout the year was computed. The electrical parameters of the 3 panels were analyzed. The effect of temperature on the electrical performance of the panel was also studied. The reduction of voltage due to increasing panel temperature was managed by MPES type Charge controller. Glass reflector with reflectivity 0.95 was chosen as the ridge wall for the concentrator system. The maximum power outputs for the 1X and 2X panel reached were 9W and 10.5W with glass reflector. The percentage of power improvement for 1X and 2X concentrations were 22.3% and 45.8% respectively. The 2X concentrated panel connected battery takes lower time to charge compared with normal panel connected battery. Copyright © 2016. Published by Elsevier Inc.

  10. Powering Lithium-Sulfur Battery Performance by Propelling Polysulfide Redox at Sulfiphilic Hosts.

    Science.gov (United States)

    Yuan, Zhe; Peng, Hong-Jie; Hou, Ting-Zheng; Huang, Jia-Qi; Chen, Cheng-Meng; Wang, Dai-Wei; Cheng, Xin-Bing; Wei, Fei; Zhang, Qiang

    2016-01-13

    Lithium-sulfur (Li-S) battery system is endowed with tremendous energy density, resulting from the complex sulfur electrochemistry involving multielectron redox reactions and phase transformations. Originated from the slow redox kinetics of polysulfide intermediates, the flood of polysulfides in the batteries during cycling induced low sulfur utilization, severe polarization, low energy efficiency, deteriorated polysulfide shuttle, and short cycling life. Herein, sulfiphilic cobalt disulfide (CoS2) was incorporated into carbon/sulfur cathodes, introducing strong interaction between lithium polysulfides and CoS2 under working conditions. The interfaces between CoS2 and electrolyte served as strong adsorption and activation sites for polar polysulfides and therefore accelerated redox reactions of polysulfides. The high polysulfide reactivity not only guaranteed effective polarization mitigation and promoted energy efficiency by 10% but also promised high discharge capacity and stable cycling performance during 2000 cycles. A slow capacity decay rate of 0.034%/cycle at 2.0 C and a high initial capacity of 1368 mAh g(-1) at 0.5 C were achieved. Since the propelling redox reaction is not limited to Li-S system, we foresee the reported strategy herein can be applied in other high-power devices through the systems with controllable redox reactions.

  11. Effects of oxygen partial pressure on Li-air battery performance

    Science.gov (United States)

    Kwon, Hyuk Jae; Lee, Heung Chan; Ko, Jeongsik; Jung, In Sun; Lee, Hyun Chul; Lee, Hyunpyo; Kim, Mokwon; Lee, Dong Joon; Kim, Hyunjin; Kim, Tae Young; Im, Dongmin

    2017-10-01

    For application in electric vehicles (EVs), the Li-air battery system needs an air intake system to supply dry oxygen at controlled concentration and feeding rate as the cathode active material. To facilitate the design of such air intake systems, we have investigated the effects of oxygen partial pressure (≤1 atm) on the performance of the Li-air cell, which has not been systematically examined. The amounts of consumed O2 and evolved CO2 from the Li-air cell are measured with a custom in situ differential electrochemical gas chromatography-mass spectrometry (DEGC-MS). The amounts of consumed O2 suggest that the oxygen partial pressure does not affect the reaction mechanism during discharge, and the two-electron reaction occurs under all test conditions. On the other hand, the charging behavior varies by the oxygen partial pressure. The highest O2 evolution ratio is attained under 70% O2, along with the lowest CO2 evolution. The cell cycle life also peaks at 70% O2 condition. Overall, an oxygen partial pressure of about 0.5-0.7 atm maximizes the Li-air cell capacity and stability at 1 atm condition. The findings here indicate that the appropriate oxygen partial pressure can be a key factor when developing practical Li-air battery systems.

  12. Electrical performance of GaN diode as betavoltaic isotope battery energy converter

    International Nuclear Information System (INIS)

    Wang Guanquan; Yang Yuqing; Liu Yebing; Hu Rui; Li Hao; Zhong Zhengkun; Luo Shunzhong

    2013-01-01

    Two kinds of GaN PiN diodes were prepared to be the energy converters of betavoltaic batteries, and irradiated by 63 Ni and 3 H radioactive sources. The I sc was 5.4 nA and V oc was 771 mV for 63 Ni source; the I sc was 10.8 nA and V oc was 839 mV for 3 H source. These results show that their V oc are far better than silicon diodes', but their I sc are poor. And there are some differences between the theory values and experiment results. There would be greatly improving space in electrical performance of beta voltaic isotope batteries with GaN diodes as the energy converters, if the dislocation could be reduced in GaN material producing process, the Ohmic contact could be prepared very well and the diodes configuration could be designed more optimizedly in the future. (authors)

  13. Electrochemical Performance of a V2O5 Cathode for a Sodium Ion Battery

    Science.gov (United States)

    Van Nghia, Nguyen; Long, Pham Duy; Tan, Ta Anh; Jafian, Samuel; Hung, I.-Ming

    2017-06-01

    In this paper, layered vanadium pentoxide (V2O5) is employed as a cathode material for a sodium ion battery. The V2O5 particle sizes range from 200 nm to 500 nm and the shapes of the aggregated V2O5 particles are non-homogeneous and irregular. The material exhibits a first discharge capacity of approximately 208.1 mAh g-1. The structure of V2O5 changes to a NaxV2O5 structure after Na+ insertion at the first discharge; the structure of NaxV2O5 remains stable␣during cycling. After 40 cycles, the discharge capacity retains 61.2% of the capacity of the second cycle. The capacity of V2O5 at a high charge/discharge current rate of 1.0 C is 49.1% of capacity at 0.1 C. Furthermore, the capacity returns to the initial value as the discharge rate returns to 0.1 C. The results of electrochemical performance tests indicate that V2O5 is a potential cathode material for sodium ion batteries.

  14. Nickel foam-supported polyaniline cathode prepared with electrophoresis for improvement of rechargeable Zn battery performance

    Science.gov (United States)

    Xia, Yang; Zhu, Derong; Si, Shihui; Li, Degeng; Wu, Sen

    2015-06-01

    Porous nickel foam is used as a substrate for the development of rechargeable zinc//polyaniline battery, and the cathode electrophoresis of PANI microparticles in non-aqueous solution is applied to the fabrication of Ni foam supported PANI electrode, in which the corrosion of the nickel foam substrate is prohibited. The Ni foam supported PANI cathode with high loading is prepared by PANI electrophoretic deposition, and followed by PANI slurry casting under vacuum filtration. The electrochemical charge storage performance for PANI material is significantly improved by using nickel foam substrate via the electrophoretic interlayer. The specific capacity of the nickel foam-PANI electrode with the electrophoretic layer is higher than the composite electrode without the electrophoretic layer, and the specific capacity of PANI supported by Ni foam reaches up to 183.28 mAh g-1 at the working current of 2.5 mA cm-2. The present electrophoresis deposition method plays the facile procedure for the immobilization of PANI microparticles onto the surface of non-platinum metals, and it becomes feasible to the use of the Ni foam supported PANI composite cathode for the Zn/PANI battery in weak acidic electrolyte.

  15. Ultrafast and directional diffusion of lithium in phosphorene for high-performance lithium-ion battery.

    Science.gov (United States)

    Li, Weifeng; Yang, Yanmei; Zhang, Gang; Zhang, Yong-Wei

    2015-03-11

    Density functional theory calculations have been performed to investigate the binding and diffusion behavior of Li in phosphorene. Our studies reveal the following findings: (1) Li atom forms strong binding with phosphorus atoms and exists in the cationic state; (2) the shallow energy barrier (0.08 eV) of Li diffusion on monolayer phosphorene along zigzag direction leads to an ultrahigh diffusivity, which is estimated to be 10(2) (10(4)) times faster than that on MoS2 (graphene) at room temperature; (3) the large energy barrier (0.68 eV) along armchair direction results in a nearly forbidden diffusion, and such strong diffusion anisotropy is absent in graphene and MoS2; (4) a remarkably large average voltage of 2.9 V is predicted in the phosphorene-based Li-ion battery; and (5) a semiconducting to metallic transition induced by Li intercalation of phosphorene gives rise to a good electrical conductivity, ideal for use as an electrode. Given these advantages, it is expected that phosphorene will present abundant opportunities for applications in novel electronic device and lithium-ion battery with a high rate capability and high charging voltage.

  16. Conductivity and electrochemical performance of LiFePO4 slurry in the lithium slurry battery

    Science.gov (United States)

    Feng, Caimei; Chen, Yongchong; Liu, Dandan; Zhang, Ping

    2017-06-01

    Lithium slurry battery is a new type of energy storage technique which uses the slurry of solid active materials, conductive additions and liquid electrolyte as the electrode. The proportion of conductive addition and the active material has significant influence on the conductivity and electrochemical performance of the slurry electrode. In the present work, slurries with different volume ratios of LiFePO4 (LFP) and Ketjenblack (KB) were investigated by the electrochemical workstation and charge-discharge testing system (vs. Li/Li+). Results show that the conductivity of the slurry increases linearly with the addition of KB, and the measured specific capacity of the slurry reaches its theoretical value when the volume ratio of KB to LFP is around 0.2. Based on this ratio, a slurry battery with higher loading of LFP (19.1 wt.% in the slurry) was tested, and a specific capacity of 165 mAh/g at 0.2 mA/cm2 and 102 mAh/g at 5 mA/cm2 was obtained for LFP.

  17. Effects of carbon additives on the performance of negative electrode of lead-carbon battery

    International Nuclear Information System (INIS)

    Zou, Xianping; Kang, Zongxuan; Shu, Dong; Liao, Yuqing; Gong, Yibin; He, Chun; Hao, Junnan; Zhong, Yayun

    2015-01-01

    Highlights: • The negative electrode sheets are prepared by simulating manufacture condition of negative plates. • The effect of carbon additives on negative electrode sheets is studied by electrochemical method. • Carbon additives in NAM enhance electrochemical properties of the negative sheets. • The negative sheets with 0.5 wt% carbon additive exhibit better electrochemical performance. • The charge-discharge mechanism is discussed in detail according to the experimental results. - Abstract: In this study, carbon additives such as activated carbon (AC) and carbon black (CB) are introduced to the negative electrode to improve its electrochemical performance, the negative electrode sheets are prepared by simulating the negative plate manufacturing process of lead-acid battery, the types and contents of carbon additives in the negative electrode sheets are investigated in detail for the application of lead-carbon battery. The electrochemical performance of negative electrode sheets are measured by chronopotentiometry, galvanostatic charge-discharge and electrochemical impedance spectroscopy, the crystal structure and morphology are characterized by X-ray diffraction and scanning electron microscopy, respectively. The experimental results indicate that the appropriate addition of AC or CB can enhance the discharge capacity and prolong the cycle life of negative electrode sheets under high-rate partial-state-of-charge conditions, AC additive exerts more obvious effect than CB additive, the optimum contents for the best electrochemical performance of the negative electrode sheets are determined as 0.5wt% for both AC and CB. The reaction mechanism of the electrochemical process is also discussed in this paper, the appropriate addition of AC or CB in negative electrode can promote the conversion of PbSO 4 to Pb, suppress the sulfation of negative electrode sheets and reduce the electrochemical reaction resistance

  18. Effect of Different Binders on the Electrochemical Performance of Metal Oxide Anode for Lithium-Ion Batteries

    Science.gov (United States)

    Wang, Rui; Feng, Lili; Yang, Wenrong; Zhang, Yinyin; Zhang, Yanli; Bai, Wei; Liu, Bo; Zhang, Wei; Chuan, Yongming; Zheng, Ziguang; Guan, Hongjin

    2017-10-01

    When testing the electrochemical performance of metal oxide anode for lithium-ion batteries (LIBs), binder played important role on the electrochemical performance. Which binder was more suitable for preparing transition metal oxides anodes of LIBs has not been systematically researched. Herein, five different binders such as polyvinylidene fluoride (PVDF) HSV900, PVDF 301F, PVDF Solvay5130, the mixture of styrene butadiene rubber and sodium carboxymethyl cellulose (SBR+CMC), and polyacrylonitrile (LA133) were studied to make anode electrodes (compared to the full battery). The electrochemical tests show that using SBR+CMC and LA133 binder which use water as solution were significantly better than PVDF. The SBR+CMC binder remarkably improve the bonding capacity, cycle stability, and rate performance of battery anode, and the capacity retention was about 87% after 50th cycle relative to the second cycle. SBR+CMC binder was more suitable for making transition metal oxides anodes of LIBs.

  19. Robust and thermal-enhanced melamine formaldehyde–modified glassfiber composite separator for high-performance lithium batteries

    International Nuclear Information System (INIS)

    Wang, Qingfu

    2015-01-01

    The composite separator of melamine formaldehyde resin coated glass microfiber membrane was prepared for high performance lithium ion battery. It was demonstrated that this composite membranes possessed a significantly enhanced tensile strength and a modified porous structure, compared with that of pristine glass microfiber membrane. Impressive improvements in thermo-stability, with no shrinkage at an elevated temperature of 150 °C. Meanwhile, such composite membrane presented a favorable wettability and remarkable electrochemical stability in commercial liquid electrolyte. In addition, the battery test results of LiCoO 2 /graphite cells proved the composite membrane was a promising separator with an improved cycling performance and rate capability. The cycle performance of LiFePO 4 /Li cells at the elevated temperature of 120 °C demonstrated their excellent safety characteristic as separator in LIB, indicating the composite membrane was a potential separator candidate for high power battery.

  20. Measurement protocols for performance testing of dosimetry services for external radiations

    International Nuclear Information System (INIS)

    1993-01-01

    In the Health and Safety Executive's ''Requirements for the Approval of Dosimetry Services under the Ionising Radiations Regulations 1985'', it is stipulated that dosimetry services seeking approval must show that they have successfully completed a performance test. The services must arrange for the tests to be carried out on application and thereafter every 18 months, by a laboratory which has received accreditation from the National Measurement Accreditation Service (NAMAS) for the whole performance testing activity. The performance tests must be carried out to published protocols and the purpose here is to provide protocols for external, whole body film and TLD dosimetry services, and for skin and extremity dosimetry services. (Author)

  1. HxMoO3 nanobelts with better performance as anode in lithium-ion batteries

    International Nuclear Information System (INIS)

    Ju, Xiaokang; Ning, Peigong; Tong, Xiaobing; Lin, Xiaoping; Pan, Xi; Li, Qiuhong; Duan, Xiaochuan; Wang, Taihong

    2016-01-01

    We first report the pure H x MoO 3 nanobelts as anode for lithium-ion batteries by a facile hydrothermal with ammonium heptamolybdate tetrahydrate ((NH 4 )6Mo 7 O 24 ∙4H 2 O) and hydrochloric acid (HCl). Owing to hydrogen-doping, Mo 5+ exists in the H x MoO 3 nanobelt, which may release extra electrons. Therefore, the electric conductance of H x MoO 3 nanobelt is enhanced greatly. Moreover, the content of hydrogen can’t be high, since the ordered structure deteriorates when amount of hydrogen increasing. The H 0.28 MoO 3 nanobelts we designed exhibit outstanding specific capacity and rate performance. The stable capacity of 920 mAh g −1 is obtained after 25 charge/discharge cycles at 100 mA g −1 . At high current densities such as 1, 2, 5 and 10 A g −1 , the H 0.28 MoO 3 electrode delivers specific capacities of about 600, 500, 420, 300 mAh g −1 , respectively. Even after 450 charge discharge cycles at 1 A g −1 , the performance of our materials can maintain the capacity of about 550 mAh g −1 . Furthermore, we provide more discussion about the lithium storage mechanism of H x MoO 3 nanobelts through ex situ XRD and FESEM. By comparing H x MoO 3 with different X, we find that low content of hydrogen can greatly improve the performance of α-MoO 3 electrodes in Li-ion batteries.

  2. Influence of misalignments on the performance of externally occulted solar coronagraphs. Application to PROBA-3/ASPIICS

    Science.gov (United States)

    Shestov, S. V.; Zhukov, A. N.

    2018-05-01

    Context. The ASPIICS instrument is a novel externally occulted coronagraph that will be launched on board the PROBA-3 mission of the European Space Agency. The external occulter will be placed on one satellite 150 m ahead of the second satellite that will carry an optical instrument. During 6 h out of 19.38 h of orbit, the satellites will fly in a precise (accuracy around a few millimeters) formation, constituting a giant externally occulted coronagraph. The large distance between the external occulter and the primary objective will allow observations of the white-light solar corona starting from extremely low heights 1.1R⊙. Aims: We intend to analyze influence of shifts of the satellites and misalignments of optical elements on the ASPIICS performance in terms of diffracted light. Based on the quantitative influence of misalignments on diffracted light, we provide a recipe for choosing the size of the internal occulter (IO) to achieve a trade-off between the minimal height of observations and sustainability to possible misalignments. Methods: We considered different types of misalignments and analyzed their influence from optical and computational points of view. We implemented a numerical model of the diffracted light and its propagation through the optical system and computed intensities of diffracted light throughout the instrument. Our numerical approach is based on a model from the literature that considered the axisymmetrical case. Here we extend the model to include nonsymmetrical cases and possible misalignments. Results: The numerical computations fully confirm the main properties of the diffracted light that we obtained from semi-analytical consideration. We obtain that relative influences of various misalignments are significantly different. We show that the internal occulter with RIO = 1.694 mm = 1.1R⊙ is large enough to compensate possible misalignments expected to occur in PROBA-3/ASPIICS. Besides that we show that apodizing the edge of the

  3. Eurados trial performance test for personal dosemeters for external beta radiation

    DEFF Research Database (Denmark)

    Christensen, P.; Bordy, J.M.; Ambrosi, P.

    2001-01-01

    On the initiative of the European Dosimetry Group (EURADOS) action group 'Harmonisation and Dosimetric Quality Assurance in Individual Monitoring for External Radiation' a trial performance test for whole-body and extremity personal dosemeters broadly representative of those in use in the EU...... the results obtained from the exercise. In particular, based on the replies to a questionnaire issued to each participant, the results are analysed in relation to important design characteristics of the dosemeters taking part in the test....

  4. A high-performance dual-scale porous electrode for vanadium redox flow batteries

    Science.gov (United States)

    Zhou, X. L.; Zeng, Y. K.; Zhu, X. B.; Wei, L.; Zhao, T. S.

    2016-09-01

    In this work, we present a simple and cost-effective method to form a dual-scale porous electrode by KOH activation of the fibers of carbon papers. The large pores (∼10 μm), formed between carbon fibers, serve as the macroscopic pathways for high electrolyte flow rates, while the small pores (∼5 nm), formed on carbon fiber surfaces, act as active sites for rapid electrochemical reactions. It is shown that the Brunauer-Emmett-Teller specific surface area of the carbon paper is increased by a factor of 16 while maintaining the same hydraulic permeability as that of the original carbon paper electrode. We then apply the dual-scale electrode to a vanadium redox flow battery (VRFB) and demonstrate an energy efficiency ranging from 82% to 88% at current densities of 200-400 mA cm-2, which is record breaking as the highest performance of VRFB in the open literature.

  5. Bilingualism and performance on two widely used developmental neuropsychological test batteries.

    Science.gov (United States)

    Karlsson, Linda C; Soveri, Anna; Räsänen, Pekka; Kärnä, Antti; Delatte, Sonia; Lagerström, Emma; Mård, Lena; Steffansson, Mikaela; Lehtonen, Minna; Laine, Matti

    2015-01-01

    The present study investigated the effect of bilingualism on the two widely used developmental neuropsychological test batteries Wechsler Intelligence Scale for Children - Fourth Edition (WISC-IV) and A Developmental Neuropsychological Assessment, Second Edition (NEPSY-II) in children. The sample consisted of 100 Finland-Swedish children in two age groups. About half (n = 52) of the participants were early simultaneous bilinguals, and the other half (n = 48) were monolinguals. As no Finland-Swedish versions of the tests are available at the moment, both tests were translated and adapted to suit this population. The results revealed no difference in the performance between bilingual and monolingual children. This speaks against a cognitive advantage in bilingual children and indicates that development of separate norms for monolingual and bilingual children is not needed for clinical use.

  6. ETK's experience in the application of VRLA batteries

    Energy Technology Data Exchange (ETDEWEB)

    Klaric, I. [Ericsson Nikola Tesla d.d., Zagreb (Croatia)

    2000-07-01

    This paper presents the experience of the company Ericsson Nikola Tesla (ETK) in the application of VRLA batteries. After a short comment on conventional lead acid batteries, the paper explains the reasons for introduction of VRLA batteries and presents our experience considering their quality, performance, hydrogen evolution, safety, service life etc. Stress is put on some internal and external factors which affect useful life, such as positive grid corrosion, ambient temperature and charging voltage. ETK also gained experience in relation to adaptation of some UPS systems to VRLA batteries. The article concludes with the list of important advantages and disadvantages of VRLA batteries compared with the flooded ones. (orig.)

  7. Study on performance of composite polymer films doped with modified molecular sieve for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zhang Yuqing; Zhang Guodong; Du Tingdong; Zhang Lizao

    2010-01-01

    To improve the tensile strength and ionic conductivity of composite polymer films for lithium-ion batteries, molecular sieves of MCM-41 modified with sulfated zirconia (SO 4 2- /ZrO 2 , SZ), denoted as MCM-41/SZ, were doped into a poly(vinylidene fluoride) (PVdF) matrix to fabricate MCM-41/SZ composite polymer films, denoted as MCM-41/SZ films. Examination by transmission electron microscope (TEM) shows that modified molecular sieves have lower aggregation and a more porous structure. Tensile strength tests were carried out to investigate the mechanical performance of MCM-41/SZ films, and then the electrochemical performance of batteries with MCM-41/SZ films as separators was tested. The results show that the tensile strength (σ t ) of MCM-41/SZ film was up to 7.8 MPa; the ionic conductivity of MCM-41/SZ film was close to 10 -3 S cm -1 at room temperature; and the coulombic efficiency of the assembled lithium-ion battery was 92% at the first cycle and reached as high as 99.99% after the 20th cycle. Meanwhile, the charge-discharge voltage plateau of the lithium-ion battery presented a stable state. Therefore, MCM-41/SZ films are a good choice as separators for lithium-ion batteries due to their high tensile strength and ionic conductivity.

  8. LiPo battery energy studies for improved flight performance of unmanned aerial systems

    Science.gov (United States)

    Chang, K.; Rammos, P.; Wilkerson, S. A.; Bundy, M.; Gadsden, S. Andrew

    2016-05-01

    Energy storage is one of the most important determinants of how long and far a small electric powered unmanned aerial system (UAS) can fly. For years, most hobby and experimentalists used heavy fuels to power small drone-like systems. Electric motors and battery storage prior to the turn of the century were either too heavy or too inefficient for flight times of any usable duration. However, with the availability of brushless electric motors and lithium-based batteries everything has changed. Systems like the Dragon Eye, Pointer, and Raven are in service performing reconnaissance, intelligence, surveillance, and target acquisition (RISTA) for more than an hour at a time. More recently, multi-rotor vehicles have expanded small UAS capabilities to include activities with hovering and persistent surveillance. Moreover, these systems coupled with the surge of small, low-cost electronics can perform autonomous and semi-autonomous missions not possible just ten years ago. This paper addresses flight time limitation issues by proposing an experimental method with procedures for system identification that may lead to modeling of energy storage in electric UAS'. Consequently, this will allow for energy storage to be used more effectively in planning autonomous missions. To achieve this, a set of baseline experiments were designed to measure the energy consumption of a mid-size UAS multi-rotor. Several different flight maneuvers were considered to include different lateral velocities, climbing, and hovering. Therefore, the goal of this paper is to create baseline flight data for each maneuver to be characterized with a certain rate of energy usage. Experimental results demonstrate the feasibility and robustness of the proposed approach. Future work will include the development of mission planning algorithms that provide realistic estimates of possible mission flight times and distances given specific mission parameters.

  9. Asymmetric Membranes Containing Micron-Size Silicon for High Performance Lithium Ion Battery Anode

    International Nuclear Information System (INIS)

    Byrd, Ian; Wu, Ji

    2016-01-01

    Micron-size Si anode is notorious for having extremely poor cycle life. It is mainly caused by the large volume change (∼300%) and poor mechanical strength of the Si electrode. Satisfying methods to address this issue are seriously lacking in literature. In this study, novel single-layer, double-layer and triple-layer asymmetric membranes containing micron-size silicon have been fabricated using a simple phase inversion method to dramatically improve its cyclability. The electrochemical performance of these asymmetric membranes as lithium ion battery anodes are evaluated and compared to pure micron-size Si powders and carbonaceous asymmetric membranes. All three types of asymmetric membrane electrodes demonstrate significantly enhanced stability as compared to pure Si powders. The single-layer asymmetric membrane has the largest capacity degradation due to the loss of pulverized Si powders from the membrane surface, only 40% of whose capacity can be retained in 100 cycles. But this performance is still much better than pure micron-size silicon electrode. After being coated with nanoporous carbonaceous layers on both sides of a single-layer asymmetric membrane to make a triple-layer asymmetric membrane (sandwich structure), the capacity retention is notably increased to 88% in 100 cycles at 610 mAh g"−"1 and 0.5C. The enhanced stability is attributed to the extra nanoporous coatings that can prevent the fractured Si powders from being leached out and allow facile lithium ion diffusions. Such a novel, efficient and scalable method may provide beneficiary guidance for designing high capacity lithium ion battery anodes with large volume change issues.

  10. Influence of H2 reduction on lignin-based hard carbon performance in lithium ion batteries

    International Nuclear Information System (INIS)

    Chang, Zhen-zhen; Yu, Bao-jun; Wang, Cheng-yang

    2015-01-01

    ABSTRACT: Lignin as a by-product of fuel alcohol industry is used to prepare hard carbon materials by acetone extraction, stabilization in N 2 at 300 °C, carbonization in N 2 and subsequent H 2 reduction at 800 °C. The effect of H 2 reduction after carbonization process on the performances of the prepared samples is systematically studied and a simple mechanism is proposed. Excitingly, it is demonstrated that the process of H 2 reduction has a favorable influence on both structures and electrochemical performances of pyrolysis sample and an obvious improvement of capacity performance is obtained with reduction treatment. A first discharge/ charge capacity of 882.2/550.5 mA h g −1 (coulombic efficiency (CE) of 62.4%) is achieved at 0.1 C (1C = 372 mA g −1 ), and even after 200 cycles at 2 C a charge capacity of 228.8 mA h g −1 (about 92.8% retention ratio) remains and CE is above 99% during cycles for H 2 reduced sample. The fabulous electrochemical performance could be attributed to high purity of acetone-extracted lignin, low surface oxygen-containing functional groups and relatively high graphitization degree of reduction sample. In a word, both the simple pyrolysis process and excellent electrochemical performance make lignin-based hard carbon a promising anode material for high-capacity and high-stability lithium ion batteries (LIBs)

  11. Synthesis and characterization of high performance electrode materials for lithium ion batteries

    Science.gov (United States)

    Hong, Jian

    Lithium-ion batteries have revolutionized portable electronics. Electrode reactions in these electrochemical systems are based on reversible intercalation of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive and higher capacity electrode materials will be required. The olivine phase lithium iron phosphate has attracted the most attention because of its low cost and safety (high thermal and chemical stability). However, it is an intriguing fundamental problem to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4/FePO 4 system. This thesis focuses on determining the rate-limit step of LiFePO4. First, a LiFePO4 material, with vanadium substituting on the P-site, was synthesized, and found that the crystal structure change may cause high lithium diffusivity. Since an accurate Li diffusion coefficient cannot be measured by traditional electrochemical method in a three-electrode cell due to the phase transformation during measurement, a new method to measure the intrinsic electronic and ionic conductivity of mixed conductive LiFePO 4 was developed. This was based on the conductivity measurements of mixed conductive solid electrolyte using electrochemical impedance spectroscopy (EIS) and blocking electrode. The effects of ionic/electronic conductivity and phase transformation on the rate performance of LiFePO4 were also first investigated by EIS and other electrochemical technologies. Based on the above fundamental kinetics studies, an optimized LiFePO4 was used as a target to deposit 1mum LiFePO4 thin film at Oak Ridge National Laboratory using radio frequency (RF) magnetron sputtering. Similar to the carbon coated LiFePO4 powder electrode, the carbon-contained RF LiFePO4 film with no preferential orientation showed excellent capacity and rate capability both at 25°C and -20

  12. Performance enhancement in vanadium redox flow battery using platinum-based electrocatalyst synthesized by polyol process

    International Nuclear Information System (INIS)

    Jeong, Sanghyun; Kim, Sunhoe; Kwon, Yongchai

    2013-01-01

    Sluggish reaction rate of [VO] 2+ /[VO 2 ] + redox couple is an obstacle to be addressed in vanadium redox flow battery (VRFB). To improve the slow reaction rate, Pt/C catalyst synthesized by polyol method is suggested. Its catalytic activity, reaction reversibility and charge–discharge performance are evaluated by half cell and single cell tests, while its crystal structure, particle size and particle distribution are measured by XRD and TEM. The XRD and TEM measurements show the polyol Pt/C catalyst has larger electrochemically active surface (EAS) area and smaller particle size than commercial Pt/C catalyst. When catalytic activities of all the catalysts are estimated, the Pt-included catalysts demonstrate high peak current ratio, small peak potential difference and high electron transfer rate constant, confirming that their catalytic activity and reaction reversibility are excellent. In charge–discharge performance tests, the catalysts indicate high efficiencies as well as low overpotential and internal resistance. Excellent performances of the Pt-included catalysts are attributed to positively charged Pts that serve as active sites for activating [VO] 2+ /[VO 2 ] + reaction. Indeed, adoption of the Pt-included catalysts, especially, use of the polyol Pt/C consisting of uniform and small particles helps improve performance of VRFB

  13. An ecologically valid performance-based social functioning assessment battery for schizophrenia.

    Science.gov (United States)

    Shi, Chuan; He, Yi; Cheung, Eric F C; Yu, Xin; Chan, Raymond C K

    2013-12-30

    Psychiatrists pay more attention to the social functioning outcome of schizophrenia nowadays. How to evaluate the real world function among schizophrenia is a challenging task due to culture difference, there is no such kind of instrument in terms of the Chinese setting. This study aimed to report the validation of an ecologically valid performance-based everyday functioning assessment for schizophrenia, namely the Beijing Performance-based Functional Ecological Test (BJ-PERFECT). Fifty community-dwelling adults with schizophrenia and 37 healthy controls were recruited. Fifteen of the healthy controls were re-tested one week later. All participants were administered the University of California, San Diego, Performance-based Skill Assessment-Brief version (UPSA-B) and the MATRICS Consensus Cognitive Battery (MCCB). The finalized assessment included three subdomains: transportation, financial management and work ability. The test-retest and inter-rater reliabilities were good. The total score significantly correlated with the UPSA-B. The performance of individuals with schizophrenia was significantly more impaired than healthy controls, especially in the domain of work ability. Among individuals with schizophrenia, functional outcome was influenced by premorbid functioning, negative symptoms and neurocognition such as processing speed, visual learning and attention/vigilance. © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Design Enhancement and Performance Examination of External Rotor Switched Flux Permanent Magnet Machine for Downhole Application

    Science.gov (United States)

    Kumar, R.; Sulaiman, E.; Soomro, H. A.; Jusoh, L. I.; Bahrim, F. S.; Omar, M. F.

    2017-08-01

    The recent change in innovation and employments of high-temperature magnets, permanent magnet flux switching machine (PMFSM) has turned out to be one of the suitable contenders for seaward boring, however, less intended for downhole because of high atmospheric temperature. Subsequently, this extensive review manages the design enhancement and performance examination of external rotor PMFSM for the downhole application. Preparatory, the essential design parameters required for machine configuration are computed numerically. At that point, the design enhancement strategy is actualized through deterministic technique. At last, preliminary and refined execution of the machine is contrasted and as a consequence, the yield torque is raised from 16.39Nm to 33.57Nm while depreciating the cogging torque and PM weight up to 1.77Nm and 0.79kg, individually. In this manner, it is inferred that purposed enhanced design of 12slot-22pole with external rotor is convenient for the downhole application.

  15. Uncovering phenotypes of poor-pitch singing: the Sung Performance Battery (SPB)

    Science.gov (United States)

    Berkowska, Magdalena; Dalla Bella, Simone

    2013-01-01

    Singing is as natural as speaking for humans. Increasing evidence shows that the layman can carry a tune (e.g., when asked to sing a well-known song or to imitate single pitches, intervals and short melodies). Yet, important individual differences exist in the general population with regard to singing proficiency. Some individuals are particularly inaccurate or imprecise in producing or imitating pitch information (poor-pitch singers), thus showing a variety of singing phenotypes. Unfortunately, so far there is not a standard set of tasks for assessing singing proficiency in the general population, allowing to uncover and characterize individual profiles of poor-pitch singing. Different tasks and analysis methods are typically used in various experiments, making the comparison of the results across studies arduous. To fill this gap we propose here a new tool for assessing singing proficiency (the Sung Performance Battery, SPB). The SPB starts from the assessment of participants' vocal range followed by five tasks: (1) single-pitch matching, (2) pitch-interval matching, (3) novel-melody matching, (4) singing from memory of familiar melodies (with lyrics and on a syllable), and (5) singing of familiar melodies (with lyrics and on a syllable) at a slow tempo indicated by a metronome. Data analysis via acoustical methods provides objective measures of pitch accuracy and precision in terms of absolute and relative pitch. The SPB has been tested in a group of 50 occasional singers. The results indicate that the battery is useful for characterizing proficient singing and for detecting cases of inaccurate and/or imprecise singing. PMID:24151475

  16. Tin–indium/graphene with enhanced initial coulombic efficiency and rate performance for lithium ion batteries

    International Nuclear Information System (INIS)

    Yang, Hongxun; Li, Ling

    2014-01-01

    Graphical abstract: -- Highlights: • Tin–indium/graphene hybrid was firstly synthesized. • Indium in the hybrid reduces charge transfer resistance of electrode. • Graphene can accommodate the volume change of nanoparticles during cycling. • Tin–indium/graphene hybrid shows enhanced initial coulombic efficiency. • Tin–indium/graphene hybrid shows enhanced rate capability. -- Abstract: Tin is an attractive anode material replacing the current commercial graphite for the next generation lithium ion batteries because of its high theoretical storage capacity and energy density. However, poor capacity retention caused by large volume changes during cycling, and low rate capability frustrate its practical application. In this study, a new ternary composite based on tin–indium alloy (Sn–In) and graphene nanosheet (GNS) was prepared via a facile solvothermal synthesis followed by thermal treatment in hydrogen and argon at 550 °C. Characterizations show that the tin–indium nanoparticles with about 100 nm in size were wrapped between the graphene nanosheets. As an anode for lithium ion batteries, the Sn–In/GNS composite exhibits a remarkably improved electrochemical performance in terms of lithium storage capacity (865.6 mAh g −1 at 100 mA g −1 rate), initial coulombic efficiency (78.6%), cycling stability (83.9% capacity retention after 50 cycles), and rate capability (493.2 mAh g −1 at 600 mA g −1 rate after 25 cycles) compared to Sn/GNS and Sn–In electrode. This improvement is attributed to the introduction of lithium activity metal, indium, which reduces the charge transfer resistance of electrode, and the graphene nanosheet which accommodates the volume change of tin–indium nanoparticles during cycling and improves electrical conductivity of material

  17. Uncovering phenotypes of poor-pitch singing: The Sung Performance Battery (SPB

    Directory of Open Access Journals (Sweden)

    Magdalena eBerkowska

    2013-10-01

    Full Text Available Singing is as natural as speaking for humans. Increasing evidence shows that the layman can carry a tune (e.g., when asked to sing a well-known song or to imitate single pitches, intervals and short melodies. Yet, important individual differences exist in the general population with regard to singing proficiency. Some individuals are particularly inaccurate or imprecise in producing or imitating pitch information (poor-pitch singers, thus showing a variety of singing phenotypes. Unfortunately, so far there is not a standard set of tasks for assessing singing proficiency in the general population, allowing to uncover and characterize individual profiles of poor-pitch singing. Different tasks and analysis methods are typically used in various experiments, making the comparison of the results across studies arduous. To fill this gap we propose here a new tool for assessing singing proficiency (the Sung Performance Battery, SPB. The SPB starts from the assessment of participants’ vocal range followed by five tasks: 1 single-pitch matching, 2 pitch-interval matching, 3 novel-melody matching, 4 singing from memory of familiar melodies (with lyrics and on a syllable, and 5 singing of familiar melodies (with lyrics and on a syllable at a slow tempo indicated by a metronome. Data analysis via acoustical methods provides objective measures of pitch accuracy and precision in terms of absolute and relative pitch. The SPB has been tested in a group of 50 occasional singers. The results indicate that the battery is useful for characterizing proficient singing and for detecting cases of inaccurate and/or imprecise singing.

  18. An All-Solid-State Fiber-Shaped Aluminum-Air Battery with Flexibility, Stretchability, and High Electrochemical Performance.

    Science.gov (United States)

    Xu, Yifan; Zhao, Yang; Ren, Jing; Zhang, Ye; Peng, Huisheng

    2016-07-04

    Owing to the high theoretical energy density of metal-air batteries, the aluminum-air battery has been proposed as a promising long-term power supply for electronics. However, the available energy density from the aluminum-air battery is far from that anticipated and is limited by current electrode materials. Herein we described the creation of a new family of all-solid-state fiber-shaped aluminum-air batteries with a specific capacity of 935 mAh g(-1) and an energy density of 1168 Wh kg(-1) . The synthesis of an electrode composed of cross-stacked aligned carbon-nanotube/silver-nanoparticle sheets contributes to the remarkable electrochemical performance. The fiber shape also provides the aluminum-air batteries with unique advantages; for example, they are flexible and stretchable and can be woven into a variety of textiles for large-scale applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Individual Pressure Vessel (PV) and Common Pressure Vessel (CPV) Nickel-Hydrogen Battery Performance Under LEO Cycling Conditions

    Science.gov (United States)

    Miller, Thomas B.; Lewis, Harlan L.

    2004-01-01

    LEO life cycle testing of Individual Pressure Vessel (PV) and Common Pressure Vessel (CPV) nickel-hydrogen cell packs have been sponsored by the NASA Aerospace Flight Battery Program. The cell packs have cycled under both 35% and 60% depth-of- discharge and temperature conditions of -5 C and +lO C. The packs have been on test since as early as 1992 and have generated a substantial database. This report will provide insight into performance trends as a function of the specific cell configuration and manufacturer for eight separate nickel-hydrogen battery cell packs.

  20. An interface-reconstruction effect for rechargeable aluminum battery in ionic liquid electrolyte to enhance cycling performances

    Directory of Open Access Journals (Sweden)

    Feng Wu

    2018-01-01

    Full Text Available Aluminum (Al metal has been regarded as a promising anode for rechargeable batteries because of its natural abundance and high theoretical specific capacity. However, rechargeable aluminum batteries (RABs using Al metal as anode display poor cycling performances owing to interface problems between anode and electrolyte. The solid-electrolyte interphase (SEI layer on the anode has been confirmed to be essential for improving cycling performances of rechargeable batteries. Therefore, we immerse the Al metal in ionic liquid electrolyte for some time before it is used as anode to remove the passive film and expose fresh Al to the electrolyte. Then the reactions of exposed Al, acid, oxygen and water in electrolyte are occurred to form an SEI layer in the cycle. Al/electrolyte/V2O5 full batteries with the thin, uniform and stable SEI layer on Al metal anode perform high discharge capacity and coulombic efficiency (CE. This work illustrates that an SEI layer is formed on Al metal anode in the cycle using a simple and effective pretreatment process and results in superior cycling performances for RABs.

  1. Assisting Patients with Disabilities to Actively Perform Occupational Activities Using Battery-Free Wireless Mice to Control Environmental Stimulation

    Science.gov (United States)

    Shih, Ching-Hsiang; Wang, Shu-Hui; Chang, Man-Ling; Kung, Ssu-Yun

    2012-01-01

    The latest studies have adopted software technology to turn the battery-free wireless mouse into a high performance object location detector using a newly developed object location detection program (OLDP). This study extended OLDP functionality to assess whether two patients recovering from cerebral vascular accidents would be able to actively…

  2. Assisting People with Disabilities in Actively Performing Designated Occupational Activities with Battery-Free Wireless Mice to Control Environmental Stimulation

    Science.gov (United States)

    Shih, Ching-Hsiang

    2013-01-01

    The latest researches use software technology (OLDP, object location detection programs) to turn a commercial high-technology product, i.e. a battery-free wireless mouse, into a high performance/precise object location detector to detect whether or not an object has been placed in the designated location. The preferred environmental stimulation is…

  3. Battery Usage and Thermal Performance of the Toyota Prius and Honda Insight for Various Chassis Dynamometer Test Procedures: Preprint

    International Nuclear Information System (INIS)

    Kelly, K. J.; Mihalic, M.; Zolot, M.

    2001-01-01

    This study describes the results from the National Renewable Energy Laboratory's (NREL) chassis dynamometer testing of a 2000 model year Honda Insight and 2001 model year Toyota Prius. The tests were conducted for the purpose of evaluating the battery thermal performance, assessing the impact of air conditioning on fuel economy and emissions, and providing information for NREL's Advanced Vehicle Simulator (ADVISOR)

  4. The effects of design parameters on the charge-discharge performance of iron-chromium redox flow batteries

    International Nuclear Information System (INIS)

    Zeng, Y.K.; Zhao, T.S.; Zhou, X.L.; Zeng, L.; Wei, L.

    2016-01-01

    Highlights: • The effects of design parameters on the ICRFB performance are investigated. • The energy efficiency of the present ICRFB reaches 80.5% at 480 mA cm"−"2. • The power density reaches 1077 and 694 mW cm"−"2 at 65 and 25 °C, respectively. • The dominant loss of ICRFBs operating at 25 and 65 °C is the ohmic loss. - Abstract: The objective of this work is to understand and identify key design parameters that influence the battery performance of iron-chromium redox flow batteries (ICRFBs). The investigated parameters include the membrane thickness, electrode compression ratio, electrode pretreatment and catalyst loading. Results show that: (i) with a thin NR-211 membrane and a high electrode compression ratio of 62.5%, the operating current density of the ICRFB can reach as high as 480 mA cm"−"2 at an energy efficiency of higher than 80%; (ii) the bismuth catalyst loading has insignificant effect on the battery performance in the range of 0.52–10.45 mg cm"−"2; (iii) the moderately oxidative thermal pretreatment of the electrode improves the energy efficiency compared to the as-received electrode while the electrode prepared with a harsh pretreatment deteriorates the battery performance; and (iv) for the present ICRFBs operating at both 25 °C and 65 °C, the dominant loss is identified to be ohmic loss rather than kinetics loss.

  5. LiFePO4 nanoparticles encapsulated in graphene nanoshells for high-performance lithium-ion battery cathodes.

    Science.gov (United States)

    Fei, Huilong; Peng, Zhiwei; Yang, Yang; Li, Lei; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

    2014-07-11

    LiFePO4 encapsulated in graphene nanoshells (LiFePO4@GNS) nanoparticles were synthesized by solid state reaction between graphene-coated Fe nanoparticles and LiH2PO4. The resulting nanocomposite was demonstrated to be a superior lithium-ion battery cathode with improved cycle and rate performances.

  6. Overcurrent Abuse of Primary Prismatic Zinc–Air Battery Cells Studying Air Supply Effects on Performance and Safety Shut-Down

    Directory of Open Access Journals (Sweden)

    Fredrik Larsson

    2017-01-01

    Full Text Available Overcurrent abuse has been performed on commercial 48 Ah primary prismatic zinc (Zn–Air battery cells with full air supply as well as with shut-off air supply. Compared to other battery technologies, e.g., lithium-ion batteries, metal–air batteries offer the possibility to physically stop the battery operation by stopping its air supply, thus offering an additional protection against severe battery damage in the case of, e.g., an accidental short circuit. This method may also reduce the electrical hazard in a larger battery system since, by stopping the air supply, the voltage can be brought to zero while maintaining the energy capacity of the battery. Measurements of overdischarge currents and current cut-off by suffocation have been performed to assess the safety of this type of Zn–air battery. The time to get to zero battery voltage is shown to mainly be determined by the volume of air trapped in the cell.

  7. Preparation of 3D nanoporous copper-supported cuprous oxide for high-performance lithium ion battery anodes.

    Science.gov (United States)

    Liu, Dequan; Yang, Zhibo; Wang, Peng; Li, Fei; Wang, Desheng; He, Deyan

    2013-03-07

    Three-dimensional (3D) nanoporous architectures can provide efficient and rapid pathways for Li-ion and electron transport as well as short solid-state diffusion lengths in lithium ion batteries (LIBs). In this work, 3D nanoporous copper-supported cuprous oxide was successfully fabricated by low-cost selective etching of an electron-beam melted Cu(50)Al(50) alloy and subsequent in situ thermal oxidation. The architecture was used as an anode in lithium ion batteries. In the first cycle, the sample delivered an extremely high lithium storage capacity of about 2.35 mA h cm(-2). A high reversible capacity of 1.45 mA h cm(-2) was achieved after 120 cycles. This work develops a promising approach to building reliable 3D nanostructured electrodes for high-performance lithium ion batteries.

  8. The Multi-Attribute Task Battery II (MATB-II) Software for Human Performance and Workload Research: A User's Guide

    Science.gov (United States)

    Santiago-Espada, Yamira; Myer, Robert R.; Latorella, Kara A.; Comstock, James R., Jr.

    2011-01-01

    The Multi-Attribute Task Battery (MAT Battery). is a computer-based task designed to evaluate operator performance and workload, has been redeveloped to operate in Windows XP Service Pack 3, Windows Vista and Windows 7 operating systems.MATB-II includes essentially the same tasks as the original MAT Battery, plus new configuration options including a graphical user interface for controlling modes of operation. MATB-II can be executed either in training or testing mode, as defined by the MATB-II configuration file. The configuration file also allows set up of the default timeouts for the tasks, the flow rates of the pumps and tank levels of the Resource Management (RESMAN) task. MATB-II comes with a default event file that an experimenter can modify and adapt

  9. Performance comparison of four lithium–ion battery technologies under calendar aging

    International Nuclear Information System (INIS)

    Eddahech, Akram; Briat, Olivier; Vinassa, Jean-Michel

    2015-01-01

    This work depicts the calendar aging results of four Li-ion battery technologies. The differences in the chemistry of Li-ion batteries was studied and revealed that cathodes containing manganese are more sensitive to state-of-charge and temperature increase than lithium–iron-phosphate or lithium–nickel–cobalt–aluminum batteries. The first step in presenting the differences in technology of the Li-ion battery is through the study of the battery voltage evolution versus the amount of charge at various states of health. This study revealed a significant increase in resistance on lithium–nickel–manganese–cobalt and lithium–manganese-oxide cells; a result which was confirmed through impedance spectroscopy measurements. Finally, a study of the comparison of the different types of Li-ion batteries was undertaken, based on the analysis of the evolution of energy efficiency with respect to aging. - Highlights: • Calendar aging results of four Li-ion battery technologies are presented. • High temperature and/or the increased state-of-charge accelerated battery aging. • We analyzed the evolution of energy efficiency with respect to aging. • Cathodes with manganese are more sensitive to SOC and temperature increase

  10. Supercapacitor performance evaluation in replacing battery based on charging and discharging current characteristics

    Science.gov (United States)

    Sani, A.; Siahaan, S.; Mubarakah, N.; Suherman

    2018-02-01

    Supercapacitor is a new device of energy storage, which has much difference between ordinary capacitors and batteries. Supercapacitor have higher capacitance and energy density than regular capacitors. The supercapacitor also has a fast charging time, as well as a long life. To be used as a battery replacement please note the internal parameters of the battery to be replaced. In this paper conducted a simulation study to utilize supercapacitor as a replacement battery. The internal parameters of the battery and the supercapacitor are obtained based on the characteristics of charging and discharging current using a predefined equivalent circuit model. The battery to be replaced is a 12-volt lead-acid type, 6.5 Ah which is used on motorcycles with 6A charging and discharging currents. Super capacitor replacement capacitor is a capacity of 1600F, 2.7V which is connected in series as many as 6 pieces with 16.2 volt terminal voltage and charging current 12A. To obtain the same supercapacitor characteristic as the battery characteristic to be replaced, modification of its internal parameters is made. The results show that the super-capacitor can replace the battery function for 1000 seconds.

  11. A novel parameter for evaluation on power performance of Ni-MH rechargeable batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lian-Xing; Tang, Xin-Cun [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Luo, Zhuo; Song, Xia-Wei; Liu, Hong-Tao [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2010-04-15

    In the work, two novel conceptions of ''capacity quality'' (CQ) and ''capacity quality coefficient'' ({lambda}) were defined to evaluate cycling power capabilities of Ni-MH rechargeable batteries when considering the effect of the kinetic limitation. For convenient comparison, the capacity quality coefficient ({lambda}) and the efficiency of charge/discharge ({eta}) were in parallel applied to characterize cycling capabilities based on the data from BYD H-3/4AAA800 Ni-MH batteries at 1C-3.5C. The results show that there is an obvious difference between {lambda} and {eta} which served as evaluation indexes for rechargeable batteries, and that the secondary battery with good capacity quality also has a good cycling capability and rate capability, especially at high rate. The introduced capacity quality not only subtly covered kinetic information of the rechargeable batteries but also factually reflected stability of the electrode materials. (author)

  12. Accounting for External Turbulence of Logistics Organizations via Performance Measurement Systems

    DEFF Research Database (Denmark)

    Bühler, Andreas; Wallenburg, Carl Marcus; Wieland, Andreas

    2016-01-01

    Purpose: This paper aims to investigate the role of upper management in designing performance measurement systems (PMS) that account for external turbulence of the organization and to show how this PMS design for turbulence impacts organizational resilience and distribution service performance....... Design/methodology/approach: Hypotheses are developed by integrating management accounting and strategic management perspectives into supply chain management and subsequently tested based on data from 431 logistics organizations (i.e. both logistics companies and internal logistics departments...... distribution service performance. Originality/value: This paper is the first to introduce the concept of PMS design for turbulence to the literature and to show that it is relevant for supply chain risk management by fostering the capabilities and the performance of logistics organizations. Further...

  13. Hydrogenation effects on the lithium ion battery performance of TiOF2

    Science.gov (United States)

    He, Min; Wang, Zhihui; Yan, Xiaodong; Tian, Lihong; Liu, Gao; Chen, Xiaobo

    2016-02-01

    Hydrogenated titanium oxyfluorides (TiOF2) nanoparticles were synthesized via one-pot hydrothermal method and subsequent hydrogenation treatment. As anode materials for lithium ion batteries, the hydrogenated TiOF2 showed a superior rate performance compared to the pristine TiOF2. A charge capacity of 118.4 mA h g-1 was achieved at the current density of 1053 mA g-1 upon 150 cycles, which was 4 times higher than that of the pristine TiOF2. The rate performance of the hydrogenated TiOF2 at different current densities of 42, 210, 1053, 2106, 5265, 10530, 21060 and 52650 mA g-1 was 2.8, 6.0, 13.2, 14.7, 21.5, 30.6, 67.9 and 483.3 times higher than those of the pristine TiOF2 electrode at the corresponding rates, respectively. The remarkable improvement of the electrochemical performance was likely related to the size breakdown in the (001) direction after hydrogenation, instead of oxygen vacancies induced better charge transfer properties.

  14. Copper nanofiber-networked cobalt oxide composites for high performance Li-ion batteries

    Directory of Open Access Journals (Sweden)

    Shim Hee-Sang

    2011-01-01

    Full Text Available Abstract We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoO x . The copper nanofibers (CuNFs were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare CoO x thin-film (CoO x TF electrodes, the CuNFs@CoO x electrodes exhibited a significant enhancement of rate performance by at least six-fold at an input current density of 3C-rate. Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network. Consequently, the CuNFs@CoO x composite structure demonstrated here can be used as a promising high-performance electrode for Li-ion batteries.

  15. Performance improvement of pasted nickel electrodes with multi-wall carbon nanotubes for rechargeable nickel batteries

    International Nuclear Information System (INIS)

    Song, Q.S.; Aravindaraj, G.K.; Sultana, H.; Chan, S.L.I.

    2007-01-01

    Carbon nanotubes (CNTs) were employed as a functional additive to improve the electrochemical performance of pasted nickel-foam electrodes for rechargeable nickel-based batteries. The nickel electrodes were prepared with spherical β-Ni(OH) 2 powder as the active material and various amounts of CNTs as additives. Galvanostatic charge/discharge cycling tests showed that in comparison with the electrode without CNTs, the pasted nickel electrode with added CNTs exhibited better electrochemical properties in the chargeability, specific discharge capacity, active material utilization, discharge voltage, high-rate capability and cycling stability. Meanwhile, the CNT addition also lowered the packing density of Ni(OH) 2 particles in the three-dimensional porous nickel-foam substrate, which could lead to the decrease in the active material loading and discharge capacity of the electrode. Hence, the amount of CNTs added to Ni(OH) 2 should be optimized to obtain a high-performance nickel electrode, and an optimum amount of CNT addition was found to be 3 wt.%. The superior electrochemical performance of the nickel electrode with CNTs could be attributed to lower electrochemical impedance and less γ-NiOOH formed during charge/discharge cycling, as indicated by electrochemical impedance spectroscopy and X-ray diffraction analyses. Thus, it was an effective method to improve the electrochemical properties of pasted nickel electrodes by adding an appropriate amount of CNTs to spherical Ni(OH) 2 as the active material

  16. Structure dependent electrochemical performance of Li-rich layered oxides in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Fang; Yao, Yuze; Wang, Haiyan; Xu, Gui-Liang; Amine, Khalil; Sun, Shi-Gang; Shao, Minhua

    2017-04-08

    Rational and precise control of the structure and dimension of electrode materials is an efficient way to improve their electrochemical performance. In this work, solvothermal or co-precipitation method is used to synthesize lithium-rich layered oxide materials of Li1.2Mn0.56Co0.12Ni0.12O2 (LLO) with various morphologies and structures, including microspheres, microrods, nanoplates, and irregular nanoparticles. These materials exhibit strong structure- dependent electrochemical properties. The porous hierarchical structured LLO microrods exhibit the best performance, delivering a discharge capacity of 264.6 mAh g(-1) at 0.5 C with over 91% retention after 100 cycles. At a high rate of 5 C, a high discharge capacity of 173.6 mAh g(-1) can be achieved. This work reveals the relationship between the morphologies and electrochemical properties of LLO cathode materials, and provides a feasible approach to fabricating robust and high-performance electrode materials for lithium-ion batteries.

  17. High-Performance Vanadium Redox Flow Batteries with Graphite Felt Electrodes

    Directory of Open Access Journals (Sweden)

    Trevor J. Davies

    2018-01-01

    Full Text Available A key objective in the development of vanadium redox flow batteries (VRFBs is the improvement of cell power density. At present, most commercially available VRFBs use graphite felt electrodes under relatively low compression. This results in a large cell ohmic resistance and limits the maximum power density. To date, the best performing VRFBs have used carbon paper electrodes, with high active area compression pressures, similar to that used in fuel cells. This article investigates the use of felt electrodes at similar compression pressures. Single cells are assembled using compression pressures of 0.2–7.5 bar and tested in a VRFB system. The highest cell compression pressure, combined with a thin Nafion membrane, achieved a peak power density of 669 mW cm−2 at a flow rate of 3.2 mL min−1 per cm2 of active area, more than double the previous best performance from a felt-VRFB. The results suggest that felt electrodes can compete with paper electrodes in terms of performance when under similar compression pressures, which should help guide electrode development and cell optimization in this important energy storage technology.

  18. Differential relations between youth internalizing/externalizing problems and cortisol responses to performance vs. interpersonal stress.

    Science.gov (United States)

    Laurent, Heidemarie; Vergara-Lopez, Chrystal; Stroud, Laura R

    2016-09-01

    Efforts to define hypothalamic-pituitary-adrenal (HPA) axis profiles conferring risk for psychopathology have yielded inconclusive results, perhaps in part due to limited assessment of the stress response. In particular, research has typically focused on HPA responses to performance tasks, while neglecting the interpersonal stressors that become salient during adolescence. In this study we investigated links between psychosocial adjustment - youth internalizing and externalizing problems, as well as competence - and HPA responses to both performance and interpersonal stressors in a normative sample of children and adolescents. Participants (n = 59) completed a set of performance (public speaking, mental arithmetic, mirror tracing) and/or interpersonal (peer rejection) tasks and gave nine saliva samples, which were assayed for cortisol. Hierarchical linear models of cortisol response trajectories in relation to child behavior checklist (CBCL) scores revealed stressor- and sex-specific associations. Whereas internalizing problems related to earlier peaking, less dynamic cortisol responses to interpersonal stress (across males and females), externalizing problems related to lower, earlier peaking and less dynamic cortisol responses to performance stress for males only, and competence-related to later peaking cortisol responses to interpersonal stress for females only. Implications for understanding contextual stress profiles underlying different forms of psychopathology are discussed.

  19. Porous Co3O4 nanorods as anode for lithium-ion battery with excellent electrochemical performance

    International Nuclear Information System (INIS)

    Guo, Jinxue; Chen, Lei; Zhang, Xiao; Chen, Haoxin

    2014-01-01

    In this manuscript, porous Co 3 O 4 nanorods are prepared through a two-step approach which is composed of hydrothermal process and heating treatment as high performance anode for lithium-ion battery. Benefiting from the porous structure and 1-dimensional features, the product becomes robust and exhibits high reversible capability, good cycling performance, and excellent rate performance. - Graphical abstract: 1D porous Co 3 O 4 nanostructure as anode for lithium-ion battery with excellent electrochemical performance. - Highlights: • A two-step route has been applied to prepare 1D porous Co 3 O 4 nanostructure. • Its porous feature facilitates the fast transport of electron and lithium ion. • Its porous structure endows it with capacities higher than its theoretical capacity. • 1D nanostructure can tolerate volume changes during lithation/delithiation cycles. • It exhibits high capacity, good cyclability and excellent rate performance

  20. Performance of lead-acid batteries. Experimental study and discharge process modelling; Desempenho de baterias chumbo-acido. Estudo experimental e modelamento do processo de descarga

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, G; Bottura, C P [Universidade Estadual de Campinas, SP (Brazil); Oliveira, M G [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica

    1985-12-31

    Commercial lead-acid batteries performance when continuously discharge is valued in this work. The model relating battery capacity and discharge current is confirmed through the analysis of experimental results relating voltage to time for various discharge currents. Such model was determined for the tested batteries and can be interpreted in terms of diffusional limitations and plate passivation. (author). 2 figs., 1 tab., 12 refs

  1. Frontal assessment battery (FAB) performance following traumatic brain injury hospitalized in an acute care setting.

    Science.gov (United States)

    Rojas, Natalia; Laguë-Beauvais, Maude; Belisle, Arielle; Lamoureux, Julie; AlSideiri, Ghusn; Marcoux, Judith; Maleki, Mohammed; Alturki, Abdulrahman Y; Anchouche, Sonia; Alquraini, Hanan; Feyz, Mitra; Guise, Elaine de

    2018-01-19

    The Frontal Assessment Battery (FAB) has been shown to be useful in several clinical settings. The aim of the present study was to examine the performance of patients with traumatic brain injury (TBI) on the FAB and to predict their acute outcome. The FAB was administered to 89 patients with mild (27 = uncomplicated and 39 = complicated) and moderate (n = 23) TBI during hospitalization in an acute care setting. The length of stay in days (LOS), Glasgow Outcome Scale-Revised score (GOSE) and Disability Rating Scale (DRS) score were collected. Results showed no significant differences between the three groups on the FAB score, but age and education were significantly associated with the FAB score. Parietal lesions were associated with lower total FAB score, and with the Similarities, Motor series and Conflicting instructions subscales, while frontal lesions were associated with lower performance on the Motor series and Conflicting instructions subscales. Total FAB score was significantly correlated with all outcome measures, and together the FAB total score and the Glasgow Coma Scale (GCS) score explained 30.8% of the variance in the DRS score. The FAB may be useful clinically to acutely assess frontal and parietal lobe functions at bedside in patients with TBI and, in combination with the GCS score to measure TBI severity, can enable clinicians to predict early outcome.

  2. Novel iron oxide nanotube arrays as high-performance anodes for lithium ion batteries

    Science.gov (United States)

    Zhong, Yuan; Fan, Huiqing; Chang, Ling; Shao, Haibo; Wang, Jianming; Zhang, Jianqing; Cao, Chu-nan

    2015-11-01

    Nanostructured iron oxides can be promising anode materials for lithium ion batteries (LIBs). However, improvement on the rate capability and/or electrochemical cycling stability of iron oxide anode materials remains a key challenge because of their poor electrical conductivities and large volume expansion during cycling. Herein, the vertically aligned arrays of one-dimensional (1D) iron oxide nanotubes with 5.8 wt% carbon have been fabricated by a novel surfactant-free self-corrosion process and subsequent thermal treatment. The as-fabricated nanotube array electrode delivers a reversible capacity of 932 mAh g-1 after 50 charge-discharge cycles at a current of 0.6 A g-1. The electrode still shows a reversible capacity of 610 mAh g-1 even at a very high rate (8.0 A g-1), demonstrating its prominent rate capability. Furthermore, the nanotube array electrode also exhibits the excellent electrochemical cycling stability with a reversible capacity of 880 mAh g-1 after 500 cycles at a current of 4 A g-1. The nanotube array electrode with superior lithium storage performance reveals the promising potential as a high-performance anode for LIBs.

  3. Rational design of hierarchical ZnO@Carbon nanoflower for high performance lithium ion battery anodes

    Science.gov (United States)

    liu, Huichao; Shi, Ludi; Li, Dongzhi; Yu, Jiali; Zhang, Han-Ming; Ullah, Shahid; Yang, Bo; Li, Cuihua; Zhu, Caizhen; Xu, Jian

    2018-05-01

    The rational structure design and strong interfacial bonding are crucially desired for high performance zinc oxide (ZnO)/carbon composite electrodes. In this context, micro-nano secondary structure design and strong dopamine coating strategies are adopted for the fabrication of flower-like ZnO/carbon (ZnO@C nanoflowers) composite electrodes. The results show the ZnO@C nanoflowers (2-6 μm) are assembled by hierarchical ZnO nanosheets (∼27 nm) and continuous carbon framework. The micro-nano secondary architecture can facilitate the penetration of electrolyte, shorten lithium ions diffusion length, and hinder the aggregation of the nanosheets. Moreover, the strong chemical interaction between ZnO and coating carbon layer via C-Zn bond improves structure stability as well as the electronic conductivity. As a synergistic result, when evaluated as lithium ion batteries (LIBs) anode, the ZnO@C nanoflower electrodes show high reversible capacity of ca. 1200 mA h g-1 at 0.1 A g-1 after 80 cycles. As well as good long-cycling stability (638 and 420 mA h g-1 at 1 and 5 A g-1 after 500 cycles, respectively) and excellent rate capability. Therefore, this rational design of ZnO@C nanoflowers electrode is a promising anode for high-performance LIBs.

  4. Characterization of systems for external insulation and retrofitting with emphasis on the thermal performance

    DEFF Research Database (Denmark)

    Rudbeck, Claus; Rose, Jørgen

    1999-01-01

    During the last decade retrofitting of buildings has received increased attention not only in northern Europe but throughout the world. Retrofitting of buildings is usually performed to solve one or more of the following problems: poor indoor climate, excessive heat losses, insufficient durability...... a building designer with such a choice, key parameters for insulation systems are described in a uniform manner stating their performance with regards to aesthetics, heat transfer, moisture, durability, fire and economy. Parameters given for the total insulation capability enable the building designer...... to include the effect of thermal bridges by performing simple calculations, a task which normally requires the use of numerical models. The results show that thermal bridges in external insulation systems may decrease their thermal resistance by more than 25%.Key parameters was calculated by the use...

  5. High thermal performance lithium-ion battery pack including hybrid active–passive thermal management system for using in hybrid/electric vehicles

    International Nuclear Information System (INIS)

    Fathabadi, Hassan

    2014-01-01

    In this study, a novel Li-ion battery pack design including hybrid active–passive thermal management system is presented. The battery pack is suitable for using in hybrid/electric vehicles. Active part of the hybrid thermal management system uses distributed thin ducts, air flow and natural convection as cooling media while the passive part utilizes phase change material/expanded graphite composite (PCM/EG) as cooling/heating component to optimize the thermal performance of the proposed battery pack. High melting enthalpy of PCM/EG composite together with melting of PCM/EG composite at the temperature of 58.9 °C remains the temperature distribution of the battery units in the desired temperature range (below 60 °C). The temperature and voltage distributions in the proposed battery pack design consisting of battery units, distributed thin ducts and PCM/EG composite are calculated by numerical solving of the related partial differential equations. Simulation results obtained by writing M-files code in Matlab environment and plotting the numerical data are presented to validate the theoretical results. A comparison between the thermal and physical characteristics of the proposed battery pack and other latest works is presented that explicitly proves the battery pack performance. - Highlights: • Novel Li-ion battery pack including active and passive thermal management systems. • The battery pack has high thermal performance for ambient temperatures until 55 °C. • Uniform temperature and voltage distributions. • The maximum observed temperature in each battery unit is less than other works. • The maximum temperature dispersion in each battery is less than other works

  6. Review and evaluation of performance measures for survival prediction models in external validation settings

    Directory of Open Access Journals (Sweden)

    M. Shafiqur Rahman

    2017-04-01

    Full Text Available Abstract Background When developing a prediction model for survival data it is essential to validate its performance in external validation settings using appropriate performance measures. Although a number of such measures have been proposed, there is only limited guidance regarding their use in the context of model validation. This paper reviewed and evaluated a wide range of performance measures to provide some guidelines for their use in practice. Methods An extensive simulation study based on two clinical datasets was conducted to investigate the performance of the measures in external validation settings. Measures were selected from categories that assess the overall performance, discrimination and calibration of a survival prediction model. Some of these have been modified to allow their use with validation data, and a case study is provided to describe how these measures can be estimated in practice. The measures were evaluated with respect to their robustness to censoring and ease of interpretation. All measures are implemented, or are straightforward to implement, in statistical software. Results Most of the performance measures were reasonably robust to moderate levels of censoring. One exception was Harrell’s concordance measure which tended to increase as censoring increased. Conclusions We recommend that Uno’s concordance measure is used to quantify concordance when there are moderate levels of censoring. Alternatively, Gönen and Heller’s measure could be considered, especially if censoring is very high, but we suggest that the prediction model is re-calibrated first. We also recommend that Royston’s D is routinely reported to assess discrimination since it has an appealing interpretation. The calibration slope is useful for both internal and external validation settings and recommended to report routinely. Our recommendation would be to use any of the predictive accuracy measures and provide the corresponding predictive

  7. Reserve lithium-thionyl chloride battery for missile applications

    Science.gov (United States)

    Planchat, J. P.; Descroix, J. P.; Sarre, G.

    A comparative performance study has been conducted for silver-zinc, thionyl chloride, and thermal batteries designed for such missile applications as ICBM guidance system power supplies. Attention is given to each of the three candidates' conformity to requirements concerning mechanical configuration, electrochemical design, electrolyte reservoir, external case, and gas generator. The silver-zinc and Li-SOCl2 candidates employ similar cell configurations and yield comparable performance. The thermal battery is found to be incapable of meeting battery case temperature-related requirements.

  8. High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method

    KAUST Repository

    Kumar, Pushpendra

    2015-01-01

    Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become a crucial and new focus of S-based Li-ion batteries. Herein, we propose to use a low temperature spraying process to fabricate graphene/S electrode material, where the ink is composed of graphene flakes and the micron-sized S particles prepared by grinding of low-cost S powders. The S particles are found to be well hosted by highly conductive graphene flakes and consequently superior cyclability (∼70% capacity retention after 250 cycles), good coulombic efficiency (∼98%) and high capacity (∼1500 mA h g-1) are obtained. The proposed approach does not require high temperature annealing or baking; hence, another great advantage is to make flexible Li-ion batteries. We have also demonstrated two types of flexible batteries using sprayed graphene/S electrodes. © The Royal Society of Chemistry 2015.

  9. Cobalt- and Cadmium-Based Metal-Organic Frameworks as High-Performance Anodes for Sodium Ion Batteries and Lithium Ion Batteries.

    Science.gov (United States)

    Dong, Caifu; Xu, Liqiang

    2017-03-01

    Two multifunctional metal-organic frameworks (MOFs) with the same coordination mode, [Co(L)(H 2 O)] n ·2nH 2 O [defined as "Co(L) MOF"] and [Cd(L)(H 2 O)] n ·2nH 2 O [defined as "Cd(L) MOF"] (L = 5-aminoisophthalic acid) have been fabricated via a simple and versatile scalable solvothermal approach at 85 °C for 24 h. The relationship between the structure of the electrode materials (especially the coordination water and different metal ions) and the electrochemical properties of MOFs have been investigated for the first time. And then the possible electrochemical mechanisms of the electrodes have been studied and proposed. In addition, MOFs/RGO hybrid materials were prepared via ball milling, which demonstrated better electrochemical performances than those of individual Co(L) MOF and Cd(L) MOF. For example, when Co(L) MOF/RGO was applied as anode for sodium ion batteries (SIBs), it retained 206 mA h g -1 after 330 cycles at 500 mA g -1 and 1185 mA h g -1 could be obtained after 50 cycles at 100 mA g -1 for lithium-ion batteries (LIBs). The high-discharge capacity, excellent cyclic stability combined with the facile synthesis procedure enable Co(L) MOF- and Cd(L) MOF-based materials to be prospective anode materials for SIBs and LIBs.

  10. External Beam Boost for Cancer of the Cervix Uteri When Intracavitary Therapy Cannot Be Performed

    International Nuclear Information System (INIS)

    Barraclough, Lisa Helen; Swindell, Ric; Livsey, Jacqueline E.; Hunter, Robin D.; Davidson, Susan E.

    2008-01-01

    Purpose: To assess the outcome of patients treated with radical radiotherapy for cervical cancer who received an external beam boost, in place of intracavitary brachytherapy (ICT), after irradiation to the whole pelvis. Methods and Materials: Case notes were reviewed for all patients treated in this way in a single center between 1996 and 2004. Patient and tumor details, the reasons why ICT was not possible, and treatment outcome were documented. Results: Forty-four patients were identified. The mean age was 56.4 years (range, 26-88 years). Clinical International Federation of Gynecology and Obstetrics or radiologic stage for Stages I, II, III, and IV, respectively, was 16%, 48%, 27%, and 7%. A total radiation dose of 54-70 Gy was given (75% received ≥60 Gy). Reasons for ICT not being performed were technical limitations in 73%, comorbidity or isolation limitations in 23%, and patient choice in 4%. The median follow-up was 2.3 years. Recurrent disease was seen in 48%, with a median time to recurrence of 2.3 years. Central recurrence was seen in 16 of the 21 patients with recurrent disease. The 5-year overall survival rate was 49.3%. The 3-year cancer-specific survival rate by stage was 100%, 70%, and 42% for Stages I, II, and III, respectively. Late Grades 1 and 2 bowel, bladder, and vaginal toxicity were seen in 41%. Late Grade 3 toxicity was seen in 2%. Conclusion: An external beam boost is a reasonable option after external beam radiotherapy to the pelvis when it is not possible to perform ICT

  11. Psychomotor Battery Approaches to Performance Prediction and Evaluation in Hyperbaric, Thermal and Vibratory Environments: Annotated Bibliographies and Integrative Review

    Science.gov (United States)

    1980-10-01

    W77-Mar78 and Vibratory Environments: Annotated Biblia - 4.-EFRIGOO EOT*_1 graphies and Integrative Review. I. CONTRACT OR GRANT NUMSER(a) David J...Papers In the third phase of the effort, the final version of the three speciai-environrneni performance battery bibliographies was corriiled and the...performance at much lower pressu. (e.g. 3 to 4 ATA when nitrogen is involved). The following sections will integrate the available liter - ature on the effects

  12. Stable cyclic performance of nickel oxide–carbon composite anode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Susantyoko, Rahmat Agung; Wang, Xinghui; Fan, Yu; Xiao, Qizhen; Fitzgerald, Eugene; Pey, Kin Leong; Zhang, Qing

    2014-01-01

    Nickel oxide (NiO) directly grown on nickel foam is regarded as a promising lithium ion battery anode material which shows good cyclic and rate performances with a theoretical specific capacity of 718 mA h g −1 . In this study, we demonstrated a carbon-incorporated NiO anode (NiO–C) with a capacity per unit area of 2.11 mA h cm −2 and 1.76 mA h cm −2 at 0.2 C and 0.5 C rates, respectively, fabricated by thermal oxidation of carbon coated nickel foam. The specific capacity of our NiO–C composite samples at 0.5 C rate is found to be typically 389.16 mA h g −1 , with a stable cyclic performance up to more than 100 cycles. This remarkable performance is apparently superior to the control samples of pure NiO samples. The improved performance is contributed to carbon incorporation which serves as a fluent channel for electrons and a flexible network preventing NiO nanostructures from structural deformation during charge and discharge processes. The advantage of using our approach is the easy preparation of the NiO–C composite using a simple two-step process: chemical vapor deposition of ethanol and annealing in air. - Highlights: • We demonstrated a directly grown NiO–C anode on nickel foam substrate. • NiO–C anode was made using simple processes: CVD of ethanol and annealing in air. • The NiO–C anode has a stable cycle life up to 102 cycles. • It has an acceptable areal capacity (1.76 mA h cm −2 at 0.5 C rate) for practical use. • Carbon provides electrons path and buffering matrix preventing NiO pulverization

  13. Particle size effect of Ni-rich cathode materials on lithium ion battery performance

    International Nuclear Information System (INIS)

    Hwang, Ilkyu; Lee, Chul Wee; Kim, Jae Chang; Yoon, Songhun

    2012-01-01

    Graphical abstract: The preparation condition of Ni-rich cathode materials was investigated. When the retention time was short, a poor cathode performance was observed. For long retention time condition, cathode performance displayed a best result at pH 12. Highlights: ► Ni-rich cathode materials (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) were prepared by co-precipitation method using separate addition of Al salt. ► Particle size of Ni-rich cathode materials became larger with increase of retention time and solution pH. ► Cathode performance was poor for low retention time. ► Optimal pH for co-precipitation was 12. -- Abstract: Herein, Ni-rich cathode materials (LiNi 0.8 Co 0.15 Al 0.05 O 2 ) in lithium ion batteries are prepared by a separate addition of Ni/Co salt and Al sol solution using a continuously stirred tank reactor. Retention time and solution pH were controlled in order to obtain high performance cathode material. Particle size increase was observed with a higher retention time of the reactants. Also, primary and secondary particles became smaller according to an increase of solution pH, which was probably due to a decrease of growth rate. From the cathode application, a high discharge capacity (175 mAh g −1 ), a high initial efficiency (90%) and a good cycleability were observed in the cathode material prepared under pH 12 condition, which was attributed to its well-developed layered property and the optimal particle size. However, rate capability was inversely proportional to the particle size, which was clarified by a decrease of charge-transfer resistance measured in the electrochemical impedance spectroscopy.

  14. Aqueous Binder Enhanced High-Performance GeP5 Anode for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jun He

    2018-02-01

    Full Text Available GeP5 is a recently reported new anode material for lithium ion batteries (LIBs, it holds a large theoretical capacity about 2300 mAh g−1, and a high rate capability due to its bi-active components and superior conductivity. However, it undergoes a large volume change during its electrochemical alloying and de-alloying with Li, a suitable binder is necessary to stable the electrode integrity for improving cycle performance. In this work, we tried to apply aqueous binders LiPAA and NaCMC to GeP5 anode, and compared the difference in electrochemical performance between them and traditional binder PVDF. As can be seen from the test result, GeP5 can keep stable in both common organic solvents and proton solvents such as water and alcohol solvents, it meets the application requirements of aqueous binders. The electrochemistry results show that the use of LiPAA binder can significantly improve the initial Coulombic efficiency, reversible capacity, and cyclability of GeP5 anode as compared to the electrodes based on NaCMC and PVDF binders. The enhanced electrochemical performance of GeP5 electrode with LiPAA binder can be ascribed to the unique high strength long chain polymer structure of LiPAA, which also provide numerous uniform distributed carboxyl groups to form strong ester groups with active materials and copper current collector. Benefit from that, the GeP5 electrode with LiPAA can also exhibit excellent rate capability, and even at low temperature, it still shows attractive electrochemical performance.

  15. Assessment of the forced air-cooling performance for cylindrical lithium-ion battery packs: A comparative analysis between aligned and staggered cell arrangements

    International Nuclear Information System (INIS)

    Yang, Naixing; Zhang, Xiongwen; Li, Guojun; Hua, Dong

    2015-01-01

    An appropriate cell arrangement plays significant role to design a highly efficient cooling system for the lithium-ion battery pack. This paper performs a comparative analysis of thermal performances on different arrangements of cylindrical cells for a LiFePO 4 battery pack. A thermal model for the battery pack is developed and is solved in couple with the governing equations of fluid flow in the numerical simulations. The experiments for model validation are conducted on a single cell of the battery pack with forced-air cooling system. The effects of longitudinal and transverse spacing on the cooling performances are analyzed for the battery pack with the aligned and the staggered arrays. Under a specified flow rate of cooling air, the maximum temperature rise is proportional to the longitudinal interval for the staggered arrays, while it is in inverse for the aligned arrangement. Increasing the transverse interval leads to the increase of the battery temperature rise for both aligned and staggered arrangements. By trade-off the design requirements (maximum temperature rise, temperature uniformity, power requirement and cooling index), an appropriate solution in term of the optimal combination of the longitudinal interval, transverse interval, and air inlet width is obtained for the aligned arrangement. - Highlights: • Forced air-cooling performance for cylindrical lithium-ion battery is evaluated. • Thermal performances for aligned and staggered cell arrangements are compared. • Geometric optimization is investigated for the battery air-cooling system

  16. The influence of variable range of motion training on neuromuscular performance and control of external loads.

    Science.gov (United States)

    Clark, Ross A; Humphries, Brendan; Hohmann, Erik; Bryant, Adam L

    2011-03-01

    Resistance training programs that emphasize high force production in different regions of the range of motion (ROM) may provide performance benefits. This study examined whether variable ROM (VROM) training, which consists of partial ROM training with countermovements performed in a different phase of the ROM for each set, results in improved functional performance. Twenty-two athletes (age 22.7 ± 2.4 years, height 1.81 ± 0.07 m, and body mass 94.6 ± 14.5 kg) with extensive resistance training backgrounds performed either a VROM or full ROM control (CON) 5-week, concentric work-matched training program. The participants were assigned to a group based on stratified randomization incorporating their strength levels and performance gains in preceding training microcycles. Testing consisted of assessing the force-ROM relationship during isokinetic and isometric bench press and ballistic bench throws, with normalized electromyography amplitude assessed during the isometric tests. Repeated-measure analyses of variance revealed that the VROM intervention significantly (p force (+15.7%), in addition to isokinetic peak force in the terminal ROM (13.5% increase). No significant differences were observed in the CON group or between groups for any other outcome measures. Analysis of the force-ROM relationship revealed that that the VROM intervention enhanced performance at shorter muscle lengths. These findings suggest that VROM training improves terminal and midrange performance gains, resulting in the athlete possessing an improved ability to control external loading and produce dynamic force.

  17. Hybrid Lithium-ion Capacitor / Lithium-ion Battery System for Extended Performance

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed task will involve the design of a hybrid power system with lithium-ion (li-ion) capacitors (LICs), li-ion batteries and solar cells. The challenge in...

  18. Synthesis and Electrochemical Performance of a Lithium Titanium Phosphate Anode for Aqueous Lithium-Ion Batteries

    KAUST Repository

    Wessells, Colin; La Mantia, Fabio; Deshazer, Heather; Huggins, Robert A.; Cui, Yi

    2011-01-01

    Lithium-ion batteries that use aqueous electrolytes offer safety and cost advantages when compared to today's commercial cells that use organic electrolytes. The equilibrium reaction potential of lithium titanium phosphate is -0.5 V with respect

  19. Inorganic Glue Enabling High Performance of Silicon Particles as Lithium Ion Battery Anode

    KAUST Repository

    Cui, Li-Feng; Hu, Liangbing; Wu, Hui; Choi, Jang Wook; Cui, Yi

    2011-01-01

    overcome the pulverization problem, however these nano-engineered silicon anodes usually involve very expensive processes and have difficulty being applied in commercial lithium ion batteries. In this study, we report a novel method using amorphous silicon

  20. High performance lithium sulfur battery with novel separator membrane for space applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA's human and robotic mission, the battery with extremely high specific energy (>500 Wh/kg) and long cycle life are urgently sought after in order to...

  1. Boosting the adsorption performance of BN nanosheet as an anode of Na-ion batteries: DFT studies

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinian, A. [Department of Engineering Science, College of Engineering, University of Tehran, P.O. Box 11365-4563, Tehran (Iran, Islamic Republic of); Soleimani-amiri, S. [Department of Chemistry, Karaj Branch, Islamic Azad University, Karaj (Iran, Islamic Republic of); Arshadi, S., E-mail: chemistry_arshadi@pnu.ac.ir [Department of Chemistry, Payame Noor University, Tehran (Iran, Islamic Republic of); Vessally, E. [Department of Chemistry, Payame Noor University, Tehran (Iran, Islamic Republic of); Edjlali, L. [Department of Chemistry, Tabriz Branch, Islamic Azad University, Tabriz (Iran, Islamic Republic of)

    2017-06-28

    Despite the high advance in the Li-ion battery technology, there exist great concerns about its lifetime, safety, cost, and low-temperature performance. It is expected that the Li-ion batteries may be replaced by Na-ion batteries (NIB) because of the low cost, nontoxicity, and wide availability of sodium. Here, we investigated the potential application of BN nanosheets in anode of NIBs by means of density functional theory calculation and introduced a strategy to increase their performance. It was shown that the Na and Na{sup +} are mainly adsorbed on the center of a hexagonal ring of BN sheet with adsorption energies of −0.08 and −33.7 kcal/mol, respectively. Replacing three N atoms of the hexagonal ring with larger P atoms significantly increases the performance of the sheet as an anode of a NIB but the replacement of B by Al decreases the performance. The initial cell voltage of LIB is increased by about 0.67 V after the P-doping which causes a high storage performance with long discharge time. The results are discussed based on the energetic, structural, orbital, charge transfer and electronic properties and provide guidelines to build better high-capacity anode materials for NIBs. - Highlights: • Potential use of BN sheet as anode in Na-ion batteries (NIB) is studied by DFT. • The replacement of B by Al decreases the performance. • The cell voltage of LIB is increased by about 0.67 V after by P-doping. • The order of performance is P-BN > BN >> Al-BN.

  2. Development of Nanoporous Carbide-Derived Carbon Electrodes for High-Performance Lithium-Ion Batteries

    Science.gov (United States)

    2011-09-01

    applications in regenerative braking in electric vehicles or to power emergency actuation systems for doors and evacuation slides in airliners. In...sodium-beta, nickel-hydrogen, and regenerative fuel cells. Primary batteries are the energy source of choice for a variety of portable consumer...hybrid electric vehicles. Applications of secondary batteries can be grouped into two categories : 1. Applications used as an energy storage device, such

  3. Scalable Upcycling Silicon from Waste Slicing Sludge for High-performance Lithium-ion Battery Anodes

    International Nuclear Information System (INIS)

    Bao, Qi; Huang, Yao-Hui; Lan, Chun-Kai; Chen, Bing-Hong; Duh, Jenq-Gong

    2015-01-01

    Silicon (Si) has been perceived as a promising next-generation anode material for lithium ion batteries (LIBs) due to its superior theoretical capacity. Despite the natural abundance of this element on Earth, large-scale production of high-purity Si nanomaterials in a green and energy-efficient way is yet to become an industrial reality. Spray-drying methods have been exploited to recover Si particles from low-value sludge produced in the photovoltaic industry, providing a massive and cost-effective Si resource for fabricating anode materials. To address such drawbacks like volume expansion, low electrical and Li + conductivity and unstable solid electrolyte interphase (SEI) formation, the recycled silicon particles have been downsized into nanoscale and shielded by a highly conductive and protective graphene multilayer through high energy ball milling. Cyclic voltammetry and electrochemical impedance spectroscopy measurements have revealed that the graphene wrapping and size reduction approach have significantly improved the electrochemical performance. It delivers an excellent reversible capacity of 1,138 mA h g −1 and a long cycle life with 73% capacity retention over 150 cycles at a high current of 450 mA g −1 . The plentiful waste conversion methodology also provides considerable opportunities for developing additional rechargeable devices, ceramic, powder metallurgy and silane/siloxane products

  4. Porous carbon-free SnSb anodes for high-performance Na-ion batteries

    Science.gov (United States)

    Choi, Jeong-Hee; Ha, Choong-Wan; Choi, Hae-Young; Seong, Jae-Wook; Park, Cheol-Min; Lee, Sang-Min

    2018-05-01

    A simple melt-spinning/chemical-etching process is developed to create porous carbon-free SnSb anodes. Sodium ion batteries (SIBs) incorporating these anodes exhibit excellent electrochemical performances by accomodating large volume changes during repeated cycling. The porous carbon-free SnSb anode produced by the melt-spinning/chemical-etching process shows a high reversible capacity of 481 mAh g-1, high ICE of 80%, stable cyclability with a high capacity retention of 99% after 100 cycles, and a fast rate capability of 327 mAh g-1 at 4C-rate. Ex-situ X-ray diffraction and high resolution-transmission electron microscopy analyses demonstrate that the synthesized porous carbon-free SnSb anodes involve the highly reversible reaction with sodium through the conversion and recombination reactions during sodiation/desodiation process. The novel and simple melt-spinning/chemical-etching synthetic process represents a technological breakthrough in the commercialization of Na alloy-able anodes for SIBs.

  5. Safety and performance of a long life lithium-thionyl chloride battery

    Science.gov (United States)

    Cieslak, W. R.; Street, H. K.

    A Li/SOCl2 'D' cell for applications requiring 10 to 15 years life at very low drain rates, typically less than 150 microA, were developed. Maximizing cell safety and reliability, while delivering very good energy density, were the goals. These goals were achieved by designing the cell to be application specific. The low-rate cell was optimized to deliver up to 16 Ah at drain rates of less than 70 mA. By virtue of its low surface area, 145 cm(sup 2), the cell demonstrated excellent safety behavior. Safety testing was performed on individual cells as well as on two-cell and four-cell batteries. Single cells did not vent when short-circuited. Benign venting in a two cell string was produced, but only when the string was partially discharged before shorting. The vent mechanism is a 300 psi rupture pressure burst disc manufactured by BS&B Safety Systems. Benign venting is defined as full opening of the 3/8 in. dia vent hole without deformation of the case. Material is expelled from the cell without flame, and the cell stack remains largely intact. Venting of the Sandia-designed low rate cell was not produced under any other abuse test conditions. The vent functions as an ultimate safety mechanism in the case of severe abuse, but resistance to venting under normal use and mild abuse conditions is key to the achievement of high reliability.

  6. Electrochemical performance of arc-produced carbon nanotubes as anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Yang, Shubin; Song, Huaihe; Chen, Xiaohong; Okotrub, A.V.; Bulusheva, L.G.

    2007-01-01

    The effects of etching process on the morphology, structure and electrochemical performance of arc-produced multiwalled carbon nanotubes (CNTs) as anode material for lithium-ion batteries were systematically investigated by TEM and a variety of electrochemical testing techniques. It was found that the etched CNTs exhibited four times higher reversible capacity than that of raw CNTs, and possessed excellent cyclability with almost 100% capacity retention after 30 cycles. The kinetic properties of three kinds of CNTs electrodes involving the pristine (CNTs-1), etched (CNTs-2) as well as etch-carbonized samples (CNTs-3) were characterized via ac impedance measurement. It was indicated that, after 30 cycles the exchange current density i 0 of etched CNTs ((7.6-7.8) x 10 -3 A cm -2 ) was higher than that of the raw CNTs (5.9 x 10 -3 A cm -2 ), suggesting the electrochemical activity of CNTs was enhanced by the etching treatment. The storage characteristics of the CNTs electrodes at room temperature and 50 o C were particularly compared. It was found that the film resistance on CNTs electrode generally tended to become large with the elongation of storage time, especially storage at high temperature. In comparison with CNTs-1 and CNTs-3, CNTs-2 exhibited more distinctly increase of film resistance, which is related with the surface properties

  7. Performance Study of Graphite Anode Slurry in Lithium-ion Flow Battery by Ball Milling

    Directory of Open Access Journals (Sweden)

    FENG Cai-mei

    2018-02-01

    Full Text Available Graphite anode slurry of lithium-ion flow battery was prepared by the method of ball milling. The morphology, conductivity, specific capacity and cycle performance of graphite anode slurry were studied. Results show that the addition of conductive carbon material can improve the suspension stability of the electrode slurry; the ball milling process can not only improve the suspension stability but also reduce the resistivity of the mixed powders of graphite and conductive carbon materials, the ball milling effect is satisfactory when the mass ratio of the balls and the solid particles is 5:1, but too high ratio of the milling ball and the solid materials can destroy the layer structure of the graphite and affect the stability of the slurry. Increasing the fraction of the graphite and conductive carbon materials can form stable electrical network structure in the slurry and improve the reversible capacity; at the premise of keeping the flowability of the electrode slurry, the reversible specific capacity can be more than 40mAh/g. The capacity loss of graphite anode slurry mainly occurs in the first charging-discharging process, as the increase of the cycles, the capacity loss rate decreases, the capacity goes stable after 5 cycles.

  8. Carbonate-linked poly(ethylene oxide) polymer electrolytes towards high performance solid state lithium batteries

    International Nuclear Information System (INIS)

    He, Weisheng; Cui, Zili; Liu, Xiaochen; Cui, Yanyan; Chai, Jingchao; Zhou, Xinhong; Liu, Zhihong; Cui, Guanglei

    2017-01-01

    The classic poly(ethylene oxide) (PEO) based solid polymer electrolyte suffers from poor ionic conductivity of ambient temperature, low lithium ion transference number and relatively narrow electrochemical window (<4.0 V vs. Li + /Li). Herein, the carbonate-linked PEO solid polymer such as poly(diethylene glycol carbonate) (PDEC) and poly(triethylene glycol carbonate) (PTEC) were explored to find out the feasibility of resolving above issues. It was proven that the optimized ionic conductivity of PTEC based electrolyte reached up to 1.12 × 10 −5 S cm −1 at 25 °C with a decent lithium ion transference number of 0.39 and a wide electrochemical window about 4.5 V vs. Li + /Li. In addition, the PTEC based Li/LiFePO 4 cell could be reversibly charged and discharged at 0.05 C-rates at ambient temperature. Moreover, the higher voltage Li/LiFe 0.2 Mn 0.8 PO 4 cell (cutoff voltage 4.35 V) possessed considerable rate capability and excellent cycling performance even at ambient temperature. Therefore, these carbonate-linked PEO electrolytes were demonstrated to be fascinating candidates for the next generation solid state lithium batteries simultaneously with high energy and high safety.

  9. Outstanding electrochemical performance of a graphene-modified graphite felt for vanadium redox flow battery application

    Science.gov (United States)

    González, Zoraida; Flox, Cristina; Blanco, Clara; Granda, Marcos; Morante, Juan R.; Menéndez, Rosa; Santamaría, Ricardo

    2017-01-01

    The development of more efficient electrode materials is essential to obtain vanadium redox flow batteries (VRFBs) with enhanced energy densities and to make these electrochemical energy storage devices more competitive. A graphene-modified graphite felt synthesized from a raw graphite felt and a graphene oxide water suspension by means of electrophoretic deposition (EPD) is investigated as a suitable electrode material in the positive side of a VRFB cell by means of cyclic voltammetry, impedance spectroscopy and charge/discharge experiments. The remarkably enhanced performance of the resultant hybrid material, in terms of electrochemical activity and kinetic reversibility towards the VO2+/VO2+, and mainly the markedly high energy efficiency of the VRFB cell (c.a. 95.8% at 25 mA cm-2) can be ascribed to the exceptional morphological and chemical characteristics of this tailored material. The 3D-architecture consisting of fibers interconnected by graphene-like sheets positively contributes to the proper development of the vanadium redox reactions and so represents a significant advance in the design of effective electrode materials.

  10. Factors affecting the performance of the Zn-Ce redox flow battery

    International Nuclear Information System (INIS)

    Nikiforidis, Georgios; Cartwright, Rory; Hodgson, David; Hall, David; Berlouis, Leonard

    2014-01-01

    The Hull Cell was used to investigate the impact of current density j on the morphology and uniformity of zinc electrodeposited from a 2.5 mol dm −3 Zn 2+ solution in 1.5 mol dm −3 methanesulfonic acid at 40 °C onto carbon-composite surfaces. The range of the applied deposition current density used was between 1 mA cm −2 and 100 mA cm −2 . Good, robust deposits were obtained when j ≥ 10 mA cm 2 whereas at j's lower than this, patchy films formed due to the competing hydrogen evolution reaction (HER) on the bare carbon-composite surface. An understanding of these effects and its application in the redox flow battery enabled both the coulombic and cell potential efficiencies to be maintained at relatively high values, 90% and 69% respectively, indicating a successful inhibition of the HER on the fully formed Zn layer. Flow velocity at the low Reynolds number in the cell (Re <200) had little impact on the electrochemical cell performance. Depletion of the cerium species became an issue for long charge times

  11. Zirconium oxide nanotube-Nafion composite as high performance membrane for all vanadium redox flow battery

    Science.gov (United States)

    Aziz, Md. Abdul; Shanmugam, Sangaraju

    2017-01-01

    A high-performance composite membrane for vanadium redox flow battery (VRB) consisting of ZrO2 nanotubes (ZrNT) and perfluorosulfonic acid (Nafion) was fabricated. The VRB operated with a composite (Nafion-ZrNT) membrane showed the improved ion-selectivity (ratio of proton conductivity to permeability), low self-discharge rate, high discharge capacity and high energy efficiency in comparison with a pristine commercial Nafion-117 membrane. The incorporation of zirconium oxide nanotubes in the Nafion matrix exhibits high proton conductivity (95.2 mS cm-1) and high oxidative stability (99.9%). The Nafion-ZrNT composite membrane exhibited low vanadium ion permeability (3.2 × 10-9 cm2 min-1) and superior ion selectivity (2.95 × 107 S min cm-3). The VRB constructed with a Nafion-ZrNT composite membrane has lower self-discharge rate maintaining an open-circuit voltage of 1.3 V for 330 h relative to a pristine Nafion membrane (29 h). The discharge capacity of Nafion-ZrNT membrane (987 mAh) was 3.5-times higher than Nafion-117 membrane (280 mAh) after 100 charge-discharge cycles. These superior properties resulted in higher coulombic and voltage efficiencies with Nafion-ZrNT membranes compared to VRB with Nafion-117 membrane at a 40 mA cm-2 current density.

  12. Graphene-encapsulated cobalt sulfides nanocages with excellent anode performances for lithium ion batteries

    International Nuclear Information System (INIS)

    Guo, Jinxue; Li, Fenfen; Sun, Yanfang; Zhang, Xiao; Tang, Lin

    2015-01-01

    Graphical abstract: Display Omitted -- Highlights: •Graphene wrapped CoS 2 nanocages are synthesized as anode materials. •Layer-by-layer assembled structures are beneficial for fast and stable Li storage. •Hollow features improve capacity, rate capability and cycling life. •The sample shows outstanding lithium storages, especially high-rate performance. -- Abstract: A layer-by-layer assembled composite of graphene nanosheets (GNSs) wrapped monodisperse cobalt sulfides (CoS 2 ) nanocages has been prepared via a solvothermal method. The flexible GNSs in the layered composite act as the effective matrix to encapsulate the monodisperse CoS 2 nanocages, buffer the volume changes and prevent the aggregation of the CoS 2 nanocages during electrochemical cycling. The loosely stacked GNSs, which are induced with the insertion of CoS 2 , are convenient for electrolyte wetting and serve as highway for the rapid electron and lithium transport. The monodisperse nanocages can supply additional space to tolerate the volume changes, shorten lithium diffusion path, and do not tend to aggregate. As a result, the specific sample can deliver a high capacity approaching 800 mA h g −1 after 150 cycles at 100 mA g −1 and 697 mA h g −1 after 300 cycles at 500 mA g −1 , in addition to good capacity retention and excellent rate capability, making it a promising candidate as next-generation anode materials for lithium-ion batteries

  13. Hard carbon coated nano-Si/graphite composite as a high performance anode for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sookyung; Li, Xiaolin; Zheng, Jianming; Yan, Pengfei; Cao, Ruiguo; Jung, Hee Joon; Wang, Chong M.; Liu, Jun; Zhang, Jiguang

    2016-08-27

    With the ever increasing demands on Li-ion batteries with higher energy densities, alternative anode with higher reversible capacity is required to replace the conventional graphite anode. Here, we demonstrate a cost-effective hydrothermal-carbonization approach to prepare the hard carbon coated nano-Si/graphite (HC-nSi/G) composite as a high performance anode for Li-ion batteries. In this hierarchical structured composite, the hard carbon coating layer not only provides an efficient pathway for electron transfer, but also alleviates the volume variation of silicon during charge/discharge processes. The HC-nSi/G composite electrode shows excellent electrochemical performances including a high specific capacity of 878.6 mAh g-1 based on the total weight of composite, good rate performance and a decent cycling stability, which is promising for practical applications.

  14. The Role of Cations on the Performance of Lithium Ion Batteries: A Quantitative Analytical Approach.

    Science.gov (United States)

    Nowak, Sascha; Winter, Martin

    2018-02-20

    Lithium ion batteries are nowadays the state-of-the-art power sources for portable electronic devices and the most promising candidate for energy storage in large-size batteries, e.g., pure and hybrid vehicles. However, the degradation of the cell components minimizes both storage and operation lifetime (calendar and cycle life), which is called aging. Due to the numerous different aging effects, in either the single constituents or their interactions with each other, many reports about methodologies and techniques, both electrochemical and analytical, can be found in the literature. However, quantitative data about the degradation effects were seldom stated. One important effect is the cation distribution and migration during operation. Metal dissolution and metal migration of the cathode and the corresponding deposition of these metals on the graphitic anode are known harmful degradation effects, especially for the formed solid electrolyte interphase on the surface of the anode. Depending on the applied cell chemistries and therefore the cathode material, different mechanisms were reported so far. For lithium manganese oxide based cells, the acidification of the electrolyte due to composition of the conduction salt is attributed as the main source of metal migration. Due to subsequent loss of manganese from the cathode, the overall performance of the cell is seriously impaired. Based on the obtained observations, this degradation mechanism was adapted to lithium nickel cobalt manganese based cells as main cause of the capacity fading. However, with the help a developed total X-ray fluorescence method and additional surface and electrolyte investigations, the proposed HF based mechanism was disproven. Instead, the migration was directly associated with material defects or mechanical spalling of the particles. Furthermore, with the obtained quantitative data of the migrated transition metals on the anode and separator, the contribution on the capacity fade was

  15. A Polysulfide-Infiltrated Carbon Cloth Cathode for High-Performance Flexible Lithium–Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Ji-Yoon Song

    2018-02-01

    Full Text Available For practical application of lithium–sulfur batteries (LSBs, it is crucial to develop sulfur cathodes with high areal capacity and cycle stability in a simple and inexpensive manner. In this study, a carbon cloth infiltrated with a sulfur-containing electrolyte solution (CC-S was utilized as an additive-free, flexible, high-sulfur-loading cathode. A freestanding carbon cloth performed double duty as a current collector and a sulfur-supporting/trapping material. The active material in the form of Li2S6 dissolved in a 1 M LiTFSI-DOL/DME solution was simply infiltrated into the carbon cloth (CC during cell fabrication, and its optimal loading amount was found to be in a range between 2 and 10 mg/cm2 via electrochemical characterization. It was found that the interwoven carbon microfibers retained structural integrity against volume expansion/contraction and that the embedded uniform micropores enabled a high loading and an efficient trapping of sulfur species during cycling. The LSB coin cell employing the CC-S electrode with an areal sulfur loading of 6 mg/cm2 exhibited a high areal capacity of 4.3 and 3.2 mAh/cm2 at C/10 for 145 cycles and C/3 for 200 cycles, respectively, with minor capacity loss (<0.03%/cycle. More importantly, such high performance could also be realized in flexible pouch cells with dimensions of 2 cm × 6 cm before and after 300 bending cycles. Simple and inexpensive preparation of sulfur cathodes using CC-S electrodes, therefore, has great potential for the manufacture of high-performance flexible LSBs.

  16. SnO2 anode surface passivation by atomic layer deposited HfO2 improves li-ion battery performance

    KAUST Repository

    Yesibolati, Nulati; Shahid, Muhammad; Chen, Wei; Hedhili, Mohamed N.; Reuter, Mark C.; Ross, Frances M.; Alshareef, Husam N.

    2014-01-01

    For the first time, it is demonstrated that nanoscale HfO2 surface passivation layers formed by atomic layer deposition (ALD) significantly improve the performance of Li ion batteries with SnO2-based anodes. Specifically, the measured battery

  17. Superior cycle performance of Sn-C/graphene nanocomposite as an anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Liang Shuzhao; Zhu Xuefeng; Lian Peichao; Yang Weishen; Wang Haihui

    2011-01-01

    A novel anode material for lithium-ion batteries, tin nanoparticles coated with carbon embedded in graphene (Sn-C/graphene), was fabricated by hydrothermal synthesis and subsequent annealing. The structure and morphology of the nanocomposite were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The size of the Sn-C nanoparticles is about 50-200 nm. The reversible specific capacity of the nanocomposite is ∼662 mAh g -1 at a specific current of 100 mA g -1 after 100 cycles, even ∼417 mAh g -1 at the high current of 1000 mA g -1 . These results indicate that Sn-C/graphene possesses superior cycle performance and high rate capability. The enhanced electrochemical performances can be ascribed to the characteristic structure of the nanocomposite with both of the graphene and carbon shells, which buffer the volume change of the metallic tin and prevent the detachment and agglomeration of pulverized tin. - Graphical abstract: Tin nanoparticles coated with carbon embedded in graphene have been successfully fabricated by hydrothermal synthesis and subsequent annealing. This nanocomposite as an anode material for lithium-ion batteries exhibits superior cycle performance. Highlights: → A novel Sn-C/graphene nanocomposite as an anode material for lithium-ion batteries. → Carbon coating and graphene improve the cycle performance of the Sn anode material. → Possess large capacity, superior cycle performance, and high rate capability.

  18. MnO2 prepared by hydrothermal method and electrochemical performance as anode for lithium-ion battery.

    Science.gov (United States)

    Feng, Lili; Xuan, Zhewen; Zhao, Hongbo; Bai, Yang; Guo, Junming; Su, Chang-Wei; Chen, Xiaokai

    2014-01-01

    Two α-MnO2 crystals with caddice-clew-like and urchin-like morphologies are prepared by the hydrothermal method, and their structure and electrochemical performance are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), galvanostatic cell cycling, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS). The morphology of the MnO2 prepared under acidic condition is urchin-like, while the one prepared under neutral condition is caddice-clew-like. The identical crystalline phase of MnO2 crystals is essential to evaluate the relationship between electrochemical performances and morphologies for lithium-ion battery application. In this study, urchin-like α-MnO2 crystals with compact structure have better electrochemical performance due to the higher specific capacity and lower impedance. We find that the relationship between electrochemical performance and morphology is different when MnO2 material used as electrochemical supercapacitor or as anode of lithium-ion battery. For lithium-ion battery application, urchin-like MnO2 material has better electrochemical performance.

  19. Bubble-Sheet-Like Interface Design with an Ultrastable Solid Electrolyte Layer for High-Performance Dual-Ion Batteries.

    Science.gov (United States)

    Qin, Panpan; Wang, Meng; Li, Na; Zhu, Haili; Ding, Xuan; Tang, Yongbing

    2017-05-01

    In this work, a bubble-sheet-like hollow interface design on Al foil anode to improve the cycling stability and rate performance of aluminum anode based dual-ion battery is reported, in which, a carbon-coated hollow aluminum anode is used as both anode materials and current collector. This anode structure can guide the alloying position inside the hollow nanospheres, and also confine the alloy sizes within the hollow nanospheres, resulting in significantly restricted volumetric expansion and ultrastable solid electrolyte interface (SEI). As a result, the battery demonstrates an excellent long-term cycling stability within 1500 cycles with ≈99% capacity retention at 2 C. Moreover, this cell displays an energy density of 169 Wh kg -1 even at high power density of 2113 W kg -1 (10 C, charge and discharge within 6 min), which is much higher than most of conventional lithium ion batteries. The interfacial engineering strategy shown in this work to stabilize SEI layer and control the alloy forming position could be generalized to promote the research development of metal anodes based battery systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Carbon-Free CoO Mesoporous Nanowire Array Cathode for High-Performance Aprotic Li-O2 Batteries.

    Science.gov (United States)

    Wu, Baoshan; Zhang, Hongzhang; Zhou, Wei; Wang, Meiri; Li, Xianfeng; Zhang, Huamin

    2015-10-21

    Although various kinds of catalysts have been developed for aprotic Li-O2 battery application, the carbon-based cathodes are still vulnerable to attacks from the discharge intermediates or products, as well as the accompanying electrolyte decomposition. To ameliorate this problem, the free-standing and carbon-free CoO nanowire array cathode was purposely designed for Li-O2 batteries. The single CoO nanowire formed as a special mesoporous structure, owing even comparable specific surface area and pore volume to the typical Super-P carbon particles. In addition to the highly selective oxygen reduction/evolution reactions catalytic activity of CoO cathodes, both excellent discharge specific capacity and cycling efficiency of Li-O2 batteries were obtained, with 4888 mAh gCoO(-1) and 50 cycles during 500 h period. Owing to the synergistic effect between elaborate porous structure and selective intermediate absorption on CoO crystal, a unique bimodal growth phenomenon of discharge products was occasionally observed, which further offers a novel mechanism to control the formation/decomposition morphology of discharge products in nanoscale. This research work is believed to shed light on the future development of high-performance aprotic Li-O2 batteries.

  1. Simulation and Performance Analysis of Lithium Battery Bank Mounted on the Hybrid Power System for Mobile Public Health Center

    Science.gov (United States)

    Busono, Pratondo; Kartini, Evvy

    2013-07-01

    Mobile medical clinic has been proposed to serve homeless people, people in the disaster area or in the remote area where no health service exist. At that site, a number of essential services such as primary health care, general health screening, medical treatment and emergency/rescue operations are required. Such services usually requires on board electrical equipments such as refrigerators, komputer, power tools and medical equipments. To supply such electrical equipments, it needs extra auxiliary power sources, in addition of standard automotive power supply. The auxiliary power source specifically design to supply non automotive load which may have similar configuration, but usually uses high power alternator rated and larger deep cycle on board battery bank. This study covers the modeling and dynamic simulation of auxiliary power source/battery to supply the medical equipment and other electrical equipments on board. It consists a variable speed diesel generator set, photovoltaic (PV) generator mounted on the roof of the car, a rechargable battery bank. As an initial step in the system design, a simulation study was performed. The simulation is conducted in the system level. Simulation results shows that dynamical behaviour by means of current density, voltage and power plot over a chosen time range, and functional behaviour such as charging and discharging characteristic of the battery bank can be obtained.

  2. High-performance batteries for electric-vehicle propulsion and stationary energy storage. Progress report, October 1977--September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P.A.; Barney, D.L.; Steunenberg, R.K.

    1978-11-01

    The research, development, and management activities of the programs at Argonne National Laboratory (ANL) and at industrial subcontractors' laboratories on high-temperature batteries during the period October 1977--September 1978 are reported. These batteries are being developed for electric-vehicle propulsion and for stationary-energy-storage applications. The present cells, which operate at 400 to 500/sup 0/C, are of a vertically oriented, prismatic design with one or more inner positive electrodes of FeS or FeS/sub 2/, facing electrodes of lithium--aluminum alloy, and molten LiCl--KCl electrolyte. During this fiscal year, cell and battery development work continued at ANL, Eagle--Picher Industries, Inc., the Energy Systems Group of Rockwell International, and Gould Inc. Related work was also in progress at the Carborundum Co., General Motors Research Laboratories, and various other organizations. A major event was the initiation of a subcontract with Eagle--Picher Industries to develop, design, and fabricate a 40-kWh battery (Mark IA) for testing in an electric van. Conceptual design studies on a 100-MWh stationary-energy-storage module were conducted as a joint effort between ANL and Rockwell International. A significant technical advance was the development of multiplate cells, which are capable of higher performance than bicells. 89 figures, 57 tables.

  3. A Nacre-Like Carbon Nanotube Sheet for High Performance Li-Polysulfide Batteries with High Sulfur Loading.

    Science.gov (United States)

    Pan, Zheng-Ze; Lv, Wei; He, Yan-Bing; Zhao, Yan; Zhou, Guangmin; Dong, Liubing; Niu, Shuzhang; Zhang, Chen; Lyu, Ruiyang; Wang, Cong; Shi, Huifa; Zhang, Wenjie; Kang, Feiyu; Nishihara, Hirotomo; Yang, Quan-Hong

    2018-06-01

    Lithium-sulfur (Li-S) batteries are considered as one of the most promising energy storage systems for next-generation electric vehicles because of their high-energy density. However, the poor cyclic stability, especially at a high sulfur loading, is the major obstacles retarding their practical use. Inspired by the nacre structure of an abalone, a similar configuration consisting of layered carbon nanotube (CNT) matrix and compactly embedded sulfur is designed as the cathode for Li-S batteries, which are realized by a well-designed unidirectional freeze-drying approach. The compact and lamellar configuration with closely contacted neighboring CNT layers and the strong interaction between the highly conductive network and polysulfides have realized a high sulfur loading with significantly restrained polysulfide shuttling, resulting in a superior cyclic stability and an excellent rate performance for the produced Li-S batteries. Typically, with a sulfur loading of 5 mg cm -2 , the assembled batteries demonstrate discharge capacities of 1236 mAh g -1 at 0.1 C, 498 mAh g -1 at 2 C and moreover, when the sulfur loading is further increased to 10 mg cm -2 coupling with a carbon-coated separator, a superhigh areal capacity of 11.0 mAh cm -2 is achieved.

  4. A binder-free sulfur/reduced graphene oxide aerogel as high performance electrode materials for lithium sulfur batteries

    Science.gov (United States)

    Nitze, Florian; Agostini, Marco; Lundin, Filippa; Palmqvist, Anders E. C.; Matic, Aleksandar

    2016-12-01

    Societies’ increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of “no battery without binder” and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm2 after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.

  5. Effects of the number of inducer blades on the anti-cavitation characteristics and external performance of a centrifugal pump

    International Nuclear Information System (INIS)

    Guo, XiaoMei; Shi, GaoPing; Zhu, ZuChao; Cui, BaoLing

    2016-01-01

    Installing an inducer upstream of the main impeller is an effective approach for improving the anti-cavitation performance of a high speed centrifugal pump. For a high-speed centrifugal pump with an inducer, the number of inducer blades can affect its internal flow and external performance. We studied the manner in which the number of inducer blades can affect the anti-cavitation characteristics and external performance of a centrifugal pump. We first use the Rayleigh-Plesset equation and the mixture model to simulate the vapor liquid flow in a centrifugal pump with an inducer, and then predict its external performance. Finally, we tested the external performance of a centrifugal pump with 2-, 3- and 4-bladed inducers, respectively. The results show that the simulations of external performance in a centrifugal pump are in accordance with our experiments. Based on this, we obtained vapor volume fraction distributions for the inducer, the impeller, and in the corresponding whole flow parts. We discovered that the vapor volume fraction of a centrifugal pump with a 3- bladed inducer is less than that of a centrifugal pump with 2- or 4-bladed inducers, which means that a centrifugal pump with a 3-bladed inducer has a better external and anti-cavitation performance.

  6. Performance improvements from imagery:evidence that internal visual imagery is superior to external visual imagery for slalom performance

    Directory of Open Access Journals (Sweden)

    Nichola eCallow

    2013-10-01

    Full Text Available We report three experiments investigating the hypothesis that use of internal visual imagery (IVI would be superior to external visual imagery (EVI for the performance of different slalom-based motor tasks. In Experiment 1, three groups of participants (IVI, EVI, and a control group performed a driving-simulation slalom task. The IVI group achieved significantly quicker lap times than EVI and the control group. In Experiment 2, participants performed a downhill running slalom task under both IVI and EVI conditions. Performance was again quickest in the IVI compared to EVI condition, with no differences in accuracy. Experiment 3 used the same group design as Experiment 1, but with participants performing a downhill ski-slalom task. Results revealed the IVI group to be significantly more accurate than the control group, with no significant differences in time taken to complete the task. These results support the beneficial effects of IVI for slalom-based tasks, and significantly advances our knowledge related to the differential effects of visual imagery perspectives on motor performance.

  7. The Impact of Internal and External Resources, and Strategic Actions in Business Networks on Firm Performance in the Software Industry

    OpenAIRE

    Anggraeni, E.

    2014-01-01

    Understanding the variance in firm performance has been an important topic in the strategic management literature. In the last two decades it has become particularly interesting as business networks increasingly have become an integrated part of a firm's environment. Besides the internal resources, the less-controlled external resources in the firm’s business networks to affect its performance too. The uncertainty associated with the lower levels of control over external resources implies tha...

  8. Enhanced jump performance when providing augmented feedback compared to an external or internal focus of attention.

    Science.gov (United States)

    Keller, Martin; Lauber, Benedikt; Gottschalk, Marius; Taube, Wolfgang

    2015-01-01

    Factors such as an external focus of attention (EF) and augmented feedback (AF) have been shown to improve performance. However, the efficacy of providing AF to enhance motor performance has never been compared with the effects of an EF or an internal focus of attention (IF). Therefore, the aim of the present study was to identify which of the three conditions (AF, EF or IF) leads to the highest performance in a countermovement jump (CMJ). Nineteen volunteers performed 12 series of 8 maximum CMJs. Changes in jump height between conditions and within the series were analysed. Jump heights differed between conditions (P jump heights at the end of the series in AF (+1.60%) and lower jump heights at the end of the series in EF (-1.79%) and IF (-1.68%) were observed. Muscle activity did not differ between conditions. The differences between conditions and within the series provide evidence that AF leads to higher performance and better progression within one series than EF and IF. Consequently, AF seems to outperform EF and IF when maximising jump height.

  9. Cycle life performance of rechargeable lithium ion batteries and mathematical modeling

    Science.gov (United States)

    Ning, Gang

    Capacity fade of commercial Sony US 18650 Li-ion batteries cycled at high discharge rates was studied at ambient temperature. Battery cycled at the highest discharge rate (3 C) shows the largest internal resistance increase of 27.7% relative to the resistance of fresh battery. It's been observed anode carbon loses 10.6% of its capability to intercalate or deintercalate Li+ after it was subjected to 300 cycles at discharge rate of 3 C. This loss dominates capacity fade of full battery. A mechanism considering continuous parasitic reaction at anode/electrolyte interface and film thickening has been proposed. First principles based charge-discharge models to simulate cycle life behavior of rechargeable Li-ion batteries have been developed. In the generalized model, transport in both electrolyte phase and solid phase were simultaneously taken into account. Under mild charge-discharge condition, transport of lithium in the electrolyte phase has been neglected in the simplified model. Both models are based on loss of the active lithium ions due to the electrochemical parasitic reaction at anode/electrolyte interface and on rise of the anode film resistance. The effect of parameters such as depth of discharge (DOD), end of charge voltage (EOCV) and overvoltage of the parasitic reaction on the cycle life behavior of a battery has been analyzed. The experimental results obtained at a charge rate of 1 C, discharge rate of 0.5 C, EOCV of 4.0 V and DOD of 0.4 have been used to validate cycle life models. Good agreement between the simulations and the experiments has been achieved up to 1968 cycles with both models. Simulation of cycle life of battery under multiple cycling regimes has also been demonstrated.

  10. A New Lamination and doping Concepts for Enhanced Li – S Battery Performance

    Energy Technology Data Exchange (ETDEWEB)

    Kumta, Prashant N. [Univ. of Pittsburgh, PA (United States); Datta, Moni K. [Univ. of Pittsburgh, PA (United States); Velikokhatnyi, Oleg [Univ. of Pittsburgh, PA (United States); Murugavel Shanthi, Pavithra [Univ. of Pittsburgh, PA (United States); Gattu, Bharat [Univ. of Pittsburgh, PA (United States)

    2017-10-01

    Lithium ion batteries (LIBs) clearly dominated the area of high-energy storage systems for the past decade with significant research and development activity focused on the development of cathode and anode materials to maximize the specific energy storage, stability, and cycle life of the batteries. However, with the increasing demand in the EV industry for low cost, low weight, and high-energy storage batteries to meet the EV everywhere grand challenge, the current focus of research has shifted towards the development of lithium sulfur batteries (LSB) owing to the high theoretical specific capacity exhibited by sulfur compared to other cathode materials currently available. Li–S battery shows a theoretical capacity of 1675 mAh/g corresponding to the formation of Li2S which makes sulfur a promising electrode to replace the layered transition metal oxides (~150 mAh/g) and LiFePO4 (~170 mAh/g) hitherto deployed in present LIB systems. Moreover, the abundance of sulfur in the earth’s crust makes it a more economical and highly attractive proposition compared to currently existing cathodes. Despite advantages of sulfur, the existing Li-S battery technology display poor cyclability, low coulombic efficiency (CE) and very low cycle life due to the following issues: 1. Polysulfide (PS) dissolution; 2. Sluggish kinetics of PS to Li2S conversion; 3. High PS diffusivity in the electrolyte; 4. Insulating nature or poor conductivity of sulfur/Li2S; 5. Volumetric expansion/contraction of sulfur; 6. Shuttling of PS along with Li+. These issues result in loss of sulfur causing mechanical disintegration, surface passivation of both anode and cathode, thereby decreasing the specific capacity and columbic efficiency (CE). Present generation sulfur cathodes also show low specific storage capacity, very poor charging rates and low loading densities. Research is needed to overcome the issues impeding Li-S battery technology development.

  11. Cycle life test. Evaluation program for secondary spacecraft cells. [performance tests on silver zinc batteries, silver cadmium batteries, and nickel cadmium batteries

    Science.gov (United States)

    Harkness, J. D.

    1976-01-01

    Considerable research is being done to find more efficient and reliable means of starting electrical energy for orbiting satellites. Rechargeable cells offer one such means. A test program is described which has been established in order to further the evaluation of certain types of cells and to obtain performance and failure data as an aid to their continued improvement. The purpose of the program is to determine the cycling performance capabilities of packs of cells under different load and temperature conditions. The various kinds of cells tested were nickel-cadmium, silver-cadmium, and silver-zinc sealed cells. A summary of the results of the life cycling program is given in this report.

  12. The feasibility and concurrent validity of performing the Movement Assessment Battery for Children - 2nd Edition via telerehabilitation technology.

    Science.gov (United States)

    Nicola, Kristy; Waugh, Jemimah; Charles, Emily; Russell, Trevor

    2018-06-01

    In rural and remote communities children with motor difficulties have less access to rehabilitation services. Telerehabilitation technology is a potential method to overcome barriers restricting access to healthcare in these areas. Assessment is necessary to guide clinical reasoning; however it is unclear which paediatric assessments can be administered remotely. The Movement Assessment Battery for Children - 2nd Edition is commonly used by various health professionals to assess motor performance of children. The aim of this study was to investigate the feasibility and concurrent validity of performing the Movement Assessment Battery for Children - 2nd Edition remotely via telerehabilitation technology compared to the conventional in-person method. Fifty-nine children enrolled in a state school (5-11 years old) volunteered to perform one in-person and one telerehabilitation mediated assessment. The order of the method of delivery and the therapist performing the assessment were randomized. After both assessments were complete, a participant satisfaction questionnaire was completed by each child. The Bland-Altman limits of agreement for the total test standard score were -3.15 to 3.22 which is smaller than a pre-determined clinically acceptable margin based on the smallest detectable change. This study establishes the feasibility and concurrent validity of the administration of the Movement Assessment Battery for Children - 2nd Edition via telerehabilitation technology. Overall, participants perceived their experience with telerehabilitation positively. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Quick charge battery

    Energy Technology Data Exchange (ETDEWEB)

    Parise, R.J.

    1998-07-01

    Electric and hybrid electric vehicles (EVs and HEVs) will become a significant reality in the near future of the automotive industry. Both types of vehicles will need a means to store energy on board. For the present, the method of choice would be lead-acid batteries, with the HEV having auxiliary power supplied by a small internal combustion engine. One of the main drawbacks to lead-acid batteries is internal heat generation as a natural consequence of the charging process as well as resistance losses. This limits the re-charging rate to the battery pack for an EV which has a range of about 80 miles. A quick turnaround on recharge is needed but not yet possible. One of the limiting factors is the heat buildup. For the HEV the auxiliary power unit provides a continuous charge to the battery pack. Therefore heat generation in the lead-acid battery is a constant problem that must be addressed. Presented here is a battery that is capable of quick charging, the Quick Charge Battery with Thermal Management. This is an electrochemical battery, typically a lead-acid battery, without the inherent thermal management problems that have been present in the past. The battery can be used in an all-electric vehicle, a hybrid-electric vehicle or an internal combustion engine vehicle, as well as in other applications that utilize secondary batteries. This is not restricted to only lead-acid batteries. The concept and technology are flexible enough to use in any secondary battery application where thermal management of the battery must be addressed, especially during charging. Any battery with temperature constraints can benefit from this advancement in the state of the art of battery manufacturing. This can also include nickel-cadmium, metal-air, nickel hydroxide, zinc-chloride or any other type of battery whose performance is affected by the temperature control of the interior as well as the exterior of the battery.

  14. Performance on a Clinical Quadriceps Activation Battery Is Related to a Laboratory Measure of Activation and Recovery After Total Knee Arthroplasty.

    Science.gov (United States)

    Bade, Michael; Struessel, Tamara; Paxton, Roger; Winters, Joshua; Baym, Carol; Stevens-Lapsley, Jennifer

    2018-01-01

    To determine the relation between performance on a clinical quadriceps activation battery with (1) activation measured by doublet interpolation and (2) recovery of quadriceps strength and functional performance after total knee arthroplasty (TKA). Planned secondary analysis of a randomized controlled trial. University research laboratory. Patients (N=162; mean age, 63±7y; 89 women) undergoing TKA. Patients were classified as high (quadriceps activation battery ≥4/6) or low (quadriceps activation battery ≤3/6) based on performance on the quadriceps activation battery measured 4 days after TKA. Differences between groups in activation and recovery at 1, 2, 3, 6, and 12 months after TKA were compared using a repeated-measures maximum likelihood model. The low quadriceps activation battery group demonstrated poorer quadriceps activation via doublet interpolation (P=.01), greater quadriceps strength loss (P=.01), and greater functional performance decline (all Pbattery group. Differences between low and high quadriceps activation battery groups on all measures did not persist at 3 and 12 months (all P>.05). Poor performance on the quadriceps activation battery early after TKA is related to poor quadriceps activation and poor recovery in the early postoperative period. Patients in the low quadriceps activation battery group took 3 months to recover to the same level as the high quadriceps activation battery group. The quadriceps activation battery may be useful in identifying individuals who need specific interventions to target activation deficits or different care pathways in the early postoperative period to speed recovery after TKA. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  15. Rechargeable batteries applications handbook

    CERN Document Server

    1998-01-01

    Represents the first widely available compendium of the information needed by those design professionals responsible for using rechargeable batteries. This handbook introduces the most common forms of rechargeable batteries, including their history, the basic chemistry that governs their operation, and common design approaches. The introduction also exposes reader to common battery design terms and concepts.Two sections of the handbook provide performance information on two principal types of rechargeable batteries commonly found in consumer and industrial products: sealed nickel-cad

  16. Micro Calorimeter for Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Santhanagopalan, Shriram [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-01

    As battery technology forges ahead and consumer demand for safer, more affordable, high-performance batteries grows, the National Renewable Energy Laboratory (NREL) has added a patented Micro Calorimeter to its existing family of R&D 100 Award-winning Isothermal Battery Calorimeters (IBCs). The Micro Calorimeter examines the thermal signature of battery chemistries early on in the design cycle using popular coin cell and small pouch cell designs, which are simple to fabricate and study.

  17. Facile Synthesis of V2O5 Hollow Spheres as Advanced Cathodes for High-Performance Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Xingyuan Zhang

    2017-01-01

    Full Text Available Three-dimensional V2O5 hollow structures have been prepared through a simple synthesis strategy combining solvothermal treatment and a subsequent thermal annealing. The V2O5 materials are composed of microspheres 2–3 μm in diameter and with a distinct hollow interior. The as-synthesized V2O5 hollow microspheres, when evaluated as a cathode material for lithium-ion batteries, can deliver a specific capacity as high as 273 mAh·g−1 at 0.2 C. Benefiting from the hollow structures that afford fast electrolyte transport and volume accommodation, the V2O5 cathode also exhibits a superior rate capability and excellent cycling stability. The good Li-ion storage performance demonstrates the great potential of this unique V2O5 hollow material as a high-performance cathode for lithium-ion batteries.

  18. High-performance lithium-ion battery and symmetric supercapacitors based on FeCo₂O₄ nanoflakes electrodes.

    Science.gov (United States)

    Mohamed, Saad Gomaa; Chen, Chih-Jung; Chen, Chih Kai; Hu, Shu-Fen; Liu, Ru-Shi

    2014-12-24

    A successive preparation of FeCo2O4 nanoflakes arrays on nickel foam substrates is achieved by a simple hydrothermal synthesis method. After 170 cycles, a high capacity of 905 mAh g(-1) at 200 mA g(-1) current density and very good rate capabilities are obtained for lithium-ion battery because of the 2D porous structures of the nanoflakes arrays. The distinctive structural features provide the battery with excellent electrochemical performance. The symmetric supercapacitor on nonaqueous electrolyte demonstrates high specific capacitance of 433 F g(-1) at 0.1 A g(-1) and 16.7 F g(-1) at high scan rate of 5 V s(-1) and excellent cyclic performance of 2500 cycles of charge-discharge cycling at 2 A g(-1) current density, revealing excellent long-term cyclability of the electrode even under rapid charge-discharge conditions.

  19. Facile synthesis of Fe-incorporated CuO nanoarrays with enhanced electrochemical performance for lithium ion full batteries

    Energy Technology Data Exchange (ETDEWEB)

    Heng, Bojun [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China); Department of Applied Physics, Wuhan University of Science and Technology, Wuhan, 430065 (China); Qing, Chen; Wang, Hai; Sun, Daming; Wang, Bixiao [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China); Tang, Yiwen, E-mail: ywtang@phy.ccnu.edu.cn [Institute of Nano-science and Technology, Central-China Normal University, Wuhan, 430079 (China)

    2015-11-15

    CuO nanoarrays (CNAs) and Fe-incorporated CuO nanoarrays (FCNAs) were fabricated by hydrothermal method. Addition of Fe salt to the reaction mixture allowed the introduction of iron oxide onto the CNAs surface, which was characterized by XPS and HRTEM. Introducing Fe ion into reaction precursor significantly affected not only the morphologies of as-prepared products but also their electrochemical performance as anode for lithium ion full battery. The FCNAs electrodes showed higher specific capacity and better capacity retention at different current densities than that of CNAs. - Highlights: • Fe-incorporated CuO nanoarrays were fabricated by hydrothermal method. • Fe salt in reaction mixture leads to iron oxides forming on the surface of CuO. • Fe-incorporating improves the lithium ion battery performance of CuO anodes.

  20. Hydrothermal Synthesis of Nanostructured MnO2 and Gamma Radiation Effects on Rechargeable Lithium Battery Performance.

    Science.gov (United States)

    Seo, Sang-Ei; Kang, Yun Ok; Jung, Sung-Hee; Choi, Seong-Ho

    2015-09-01

    Nanostructured manganese dioxide (MnO2) was synthesized by the hydrothermal method under various experimental conditions such as reaction time and concentration in order to obtain nanostructure material with different morphologies, and it was found that the morphology of the MnO2 obtained had a nanoparticle-like structure, urchin-like structure, or nanorod-like structure depending on the experimental conditions. Among the as-prepared MnO2 samples, the highest surface area was seen for the urchin-like structure, and this was irradiated by γ-rays with a total radiation dose of 30 kGy at a rate 1.0 x 10(4) Gy/h in order to determine the effect of γ-irradiation on battery performance. There was a decrease in battery performance in terms of capacity and stability for irradiated samples during 100 cycles.

  1. Micro-Spherical Sulfur/Graphene Oxide Composite via Spray Drying for High Performance Lithium Sulfur Batteries

    Science.gov (United States)

    Tian, Yuan; Sun, Zhenghao; Zhang, Yongguang; Yin, Fuxing

    2018-01-01

    An efficient, industry-accepted spray drying method was used to synthesize micro-spherical sulfur/graphene oxide (S/GO) composites as cathode materials within lithium sulfur batteries. The as-designed wrapping of the sulfur-nanoparticles, with wrinkled GO composites, was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The unique morphological design of this material enabled superior discharge capacity and cycling performance, demonstrating a high initial discharge capacity of 1400 mAh g−1 at 0.1 C. The discharge capacity remained at 828 mAh g−1 after 150 cycles. The superior electrochemical performance indicates that the S/GO composite improves electrical conductivity and alleviates the shuttle effect. This study represents the first time such a facile spray drying method has been adopted for lithium sulfur batteries and used in the fabrication of S/GO composites. PMID:29346303

  2. Effects of lead-foam grids on performance of VRLA battery

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Changsong; Yi, Tingfeng; Wang, Dianlong; Hu, Xinguo [Department of Applied Chemistry, Harbin Institute of Technology, P.O. Box 411, Harbin 150001 (China)

    2006-08-25

    Lead-foam grids have been prepared by electrodepositing lead on a copper-foam substrate that has good conductibility and a symmetrically three-dimensional reticulated structure. VRLA batteries with lead foam as the negative electrode current collector material have been fabricated; the effects of the lead foam on the specific capacity, the active material utilization efficiency and the negative active material transformation process of the VRLA batteries have been studied. The results show that a lead-foam grid has a bigger specific surface area than a cast grid. The charge voltage of a VRLA battery with a lead-foam negative electrode is significantly lower than that of a VRLA battery with a cast grid electrode during a charge process. The discharge capacity, the mass specific capacity, and the active material utilization efficiency of a VRLA battery with a lead-foam electrode can be greatly improved at different states of discharge. The EIS research revealed that a lead-foam negative electrode has higher electrochemical reactivity. Observed by means of a scanning electron microscope, it was found that the spongy Pb crystals at a lead-foam grid negative electrode are smaller than that of a cast grid negative electrode at a state of charge; while the PbSO{sub 4} crystals are smaller than that of a cast grid negative electrode at a state of discharge. (author)

  3. Button batteries

    Science.gov (United States)

    Swallowing batteries ... These devices use button batteries: Calculators Cameras Hearing aids Penlights Watches ... If a person puts the battery up their nose and breathes it further in, ... problems Cough Pneumonia (if the battery goes unnoticed) ...

  4. The electrochemical performance and mechanism of cobalt (II) fluoride as anode material for lithium and sodium ion batteries

    International Nuclear Information System (INIS)

    Tan, Jinli; Liu, Li; Guo, Shengping; Hu, Hai; Yan, Zichao; Zhou, Qian; Huang, Zhifeng; Shu, Hongbo; Yang, Xiukang; Wang, Xianyou

    2015-01-01

    Highlights: •The as-prepared CoF 2 shows excellent electrochemical performance as anode material for lithium ion batteries. •The Li insertion/extraction mechanism of CoF 2 below 1.2 V was firstly proposed. •The electrochemical performance of CoF 2 as anode material in sodium ion batteries was firstly studied. -- Abstract: Cobalt (II) fluoride begins to enter into the horizons of people along with the research upsurge of metal fluorides. It is very significative and theoretically influential to make certain its electrochemical reaction mechanism. In this work, we discover a new and unrevealed reversible interfacial intercalation mechanism reacting below 1.2 V for cobalt (II) fluoride electrode material, which contributes a combined discharge capacity of about 400 mA h g −1 with the formation of SEI film at the initial discharge process. A highly reversible storage capacity of 120 mA h g −1 is observed when the cell is cycled over the voltage of 0.01-1.2 V at 0.2 C, and the low-potential voltage reaction process has a significant impact for the whole electrochemical process. Electrochemical analyses suggest that pure cobalt (II) fluoride shows better electrochemical performance when it is cycled at 3.2-0.01 V compared to the high range (1.0-4.5 V). So, we hold that cobalt (II) fluoride is more suitable to serve as anode material for lithium ion batteries. In addition, we also try to reveal the relevant performance and reaction mechanism, and realize the possibility of cobalt (II) fluoride as anode material for sodium ion batteries

  5. Methods of synthesis and performance improvement of lithium iron phosphate for high rate Li-ion batteries: A review

    Directory of Open Access Journals (Sweden)

    T.V.S.L. Satyavani

    2016-03-01

    Full Text Available Lithium ion battery technology has the potential to meet the requirements of high energy density and high power density applications. A continuous search for novel materials is pursued continually to exploit the latent potential of this technology. In this review paper, methods for preparation of Lithium Iron Phosphate are discussed which include solid state and solution based synthesis routes. The methods to improve the electrochemical performance of lithium iron phosphate are presented in detail.

  6. Performance of external and internal coil configurations for prostate investigations at 7 Tesla

    Science.gov (United States)

    Metzger, Gregory J.; van de Moortele, Pierre-Francois; Akgun, Can; Snyder, Carl J.; Moeller, Steen; Strupp, John; Andersen, Peter; Shrivastava, Devashish; Vaughan, Tommy; Ugurbil, Kamil; Adriany, Gregor

    2010-01-01

    Three different coil configurations were evaluated through simulation and experimentally to determine safe operating limits and evaluate subject size dependent performance for prostate imaging at 7 Tesla. The coils included a transceiver endorectal coil (trERC), a 16 channel transceiver external surface array (trESA) and a trESA combined with a receive-only ERC (trESA+roERC). While the transmit B1 (B1+) homogeneity was far superior for the trESA, the maximum achievable B1+ is subject size dependent and limited by transmit chain losses and amplifier performance. For the trERC, limitations in transmit homogeneity greatly compromised image quality and limited coverage of the prostate. Despite these challenges, the high peak B1+ close to the trERC and subject size independent performance provides potential advantages especially for spectroscopic localization where high bandwidth RF pulses are required. On the receive side, the combined trESA+roERC provided the highest SNR and improved homogeneity over the trERC resulting in better visualization of the prostate and surrounding anatomy. In addition, the parallel imaging performance of the trESA+roERC holds strong promise for diffusion weighted imaging and dynamic contrast enhanced MRI. PMID:20740657

  7. Thermal Performance of the LHC External Auxiliary Bus-Bar Tube Mathematical Modelling

    CERN Document Server

    Kowalczyk, P; Sacré, P; Skoczen, Blazej

    1998-01-01

    The Large Hadron Collider (LHC) externally routed auxiliary bus-bar tube (EAB) will house the electrical feeders of the LHC short straight section (SSS) correcting magnets. The superconducting wires w ill be contained in a stainless steel tube and immersed in a quasi-static helium bath. The EAB thermal performance during the cooling of the magnets down to the operating temperature of 1.9 K is studi ed. A 3-d finite element thermal model of the EAB during a cooling process from 293 K to 4.5 K is described. The semi-analytical model of the EAB cool-down from 4.5 K to 1.9 K is also presented.

  8. Characteristics of Pediatric Performance on a Test Battery Commonly Used in the Diagnosis of Central Auditory Processing Disorder.

    Science.gov (United States)

    Weihing, Jeffrey; Guenette, Linda; Chermak, Gail; Brown, Mallory; Ceruti, Julianne; Fitzgerald, Krista; Geissler, Kristin; Gonzalez, Jennifer; Brenneman, Lauren; Musiek, Frank

    2015-01-01

    Although central auditory processing disorder (CAPD) test battery performance has been examined in adults with neurologic lesions of the central auditory nervous system (CANS), similar data on children being referred for CAPD evaluations are sparse. This study characterizes CAPD test battery performance in children using tests commonly administered to diagnose the disorder. Specifically, this study describes failure rates for various test combinations, relationships between CAPD tests used in the battery, and the influence of cognitive function on CAPD test performance and CAPD diagnosis. A comparison is also made between the performance of children with CAPD and data from patients with neurologic lesions of the CANS. A retrospective study. Fifty-six pediatric patients were referred for CAPD testing. Participants were administered four CAPD tests, including frequency patterns (FP), low-pass filtered speech (LPFS), dichotic digits (DD), and competing sentences (CS). In addition, they were given the Wechsler Intelligence Scale for Children (WISC). Descriptive analyses examined the failure rates of various test combinations, as well as how often children with CAPD failed certain combinations when compared with adults with CANS lesions. A principal components analysis was performed to examine interrelationships between tests. Correlations and regressions were conducted to determine the relationship between CAPD test performance and the WISC. Results showed that the FP and LPFS tests were most commonly failed by children with CAPD. Two-test combinations that included one or both of these two tests and excluded DD tended to be failed more often. Including the DD and CS test in a battery benefited specificity. Tests thought to measure interhemispheric transfer tended to be correlated. Compared with adult patients with neurologic lesions, children with CAPD tended to fail LPFS more frequently and DD less frequently. Both groups failed FP with relatively equal frequency

  9. Stannous sulfide/multi-walled carbon nanotube hybrids as high-performance anode materials of lithium-ion batteries

    International Nuclear Information System (INIS)

    Li, Shuankui; Zuo, Shiyong; Wu, Zhiguo; Liu, Ying; Zhuo, Renfu; Feng, Juanjuan; Yan, De; Wang, Jun; Yan, Pengxun

    2014-01-01

    A hybrid of multi-walled carbon nanotubes (MWCNTs) anchored with SnS nanosheets is synthesized through a simple solvothermal method for the first time. Interestingly, SnS can be controllably deposited onto the MWCNTs backbone in the shape of nanosheets or nanoparticles to form two types of SnS/MWCNTs hybrids, SnS NSs/MWCNTs and SnS NPs/MWCNTs. When evaluated as an anode material for lithium-ion batteries, the hybrids exhibit higher lithium storage capacities and better cycling performance compared to pure SnS. It is found that the SnS NSs/MWCNTs hybrid exhibits a large reversible capacity of 620mAhg −1 at a current of 100mAg −1 as an anode material for lithium-ion batteries, which is better than SnS NPs/MWCNTs. The improved performance may be attributed to the ultrathin nanosheet subunits possess short distance for Li + ions diffusion and large electrode-electrolyte contact area for high Li + ions flux across the interface. It is believed that the structural design of electrodes demonstrated in this work will have important implications on the fabrication of high-performance electrode materials for lithium-ion batteries

  10. Enhancement of micro-grid performance during islanding mode using storage batteries and new fuzzy logic pitch angle controller

    International Nuclear Information System (INIS)

    Kamel, Rashad M.; Chaouachi, A.; Nagasaka, Ken

    2011-01-01

    Research highlights: → Novel fuzzy pitch angle controller is proposed for smoothing wind fluctuation. → Storage batteries are used for performance improve of MG in islanding mode. → Those new techniques are compared with conventional PI pitch angle controller. -- Abstract: Power system deregulation, shortage of transmission capacities and needing to reduce green house gas have led to increase interesting in distributed generations (DGs) especially renewable sources. This study developed a complete model able to analysis and simulates in details the transient dynamic performance of the Micro-Grid (MG) during and subsequent islanding process. Wind speed fluctuations cause high fluctuations in output power of wind turbine which lead to fluctuations of frequency and voltages of the MG during the islanding mode. In this paper a new fuzzy logic pitch angle controller is proposed to smooth the output power of wind turbine to reduce MG frequency and voltage fluctuations during the islanding mode. The proposed fuzzy logic pitch controller is compared with the conventional PI pitch angle controller which usually used for wind turbine power control. Results proved the effectiveness of the proposed fuzzy controller in improvement of the MG performance. Also, this paper proposed using storage batteries technique to reduce the frequency deviation and fluctuations originated from wind power solar power fluctuations. Results indicate that the storage batteries technique is superior than fuzzy logic pitch controller in reducing frequency deviation, but with more expensive than the fuzzy controller. All models and controllers are built using Matlab (registered) Simulink (registered) environment.

  11. Enhanced performance of lithium-sulfur batteries with an ultrathin and lightweight MoS2/carbon nanotube interlayer

    Science.gov (United States)

    Yan, Lingjia; Luo, Nannan; Kong, Weibang; Luo, Shu; Wu, Hengcai; Jiang, Kaili; Li, Qunqing; Fan, Shoushan; Duan, Wenhui; Wang, Jiaping

    2018-06-01

    Ultrathin and lightweight MoS2/carbon nanotube (CNT) interlayers are developed to effectively trap polysulfides in high-performance lithium-sulfur (Li-S) batteries. The MoS2/CNT interlayer is constructed by loading MoS2 nanosheets onto a cross-stacked CNT film. The CNT film with excellent conductivity and superior mechanical properties provides the Li-S batteries with a uniform conductive network, a supporting skeleton for the MoS2 nanosheets, as well as a physical barrier for the polysulfides. Moreover, chemical interactions and bonding between the MoS2 nanosheets and the polysulfides are evident. The electrode with the MoS2/CNT interlayer delivers an attractive specific capacity of 784 mA h g-1 at a high capacity rate of 10 C. In addition, the electrode demonstrates a high initial capacity of 1237 mA h g-1 and a capacity fade as low as -0.061% per cycle over 500 charge/discharge cycles at 0.2 C. The problem of self-discharge can also be suppressed with the introduction of the MoS2/CNT interlayer. The simple fabrication procedure, which is suitable for commercialization, and the outstanding electrochemical performance of the cells with the MoS2/CNT interlayer demonstrate a great potential for the development of high-performance Li-S batteries.

  12. Graphene-Embedded Co3O4 Rose-Spheres for Enhanced Performance in Lithium Ion Batteries.

    Science.gov (United States)

    Jing, Mingjun; Zhou, Minjie; Li, Gangyong; Chen, Zhengu; Xu, Wenyuan; Chen, Xiaobo; Hou, Zhaohui

    2017-03-22

    Co 3 O 4 has been widely studied as a promising candidate as an anode material for lithium ion batteries. However, the huge volume change and structural strain associated with the Li + insertion and extraction process leads to the pulverization and deterioration of the electrode, resulting in a poor performance in lithium ion batteries. In this paper, Co 3 O 4 rose-spheres obtained via hydrothermal technique are successfully embedded in graphene through an electrostatic self-assembly process. Graphene-embedded Co 3 O 4 rose-spheres (G-Co 3 O 4 ) show a high reversible capacity, a good cyclic performance, and an excellent rate capability, e.g., a stable capacity of 1110.8 mAh g -1 at 90 mA g -1 (0.1 C), and a reversible capacity of 462.3 mAh g -1 at 1800 mA g -1 (2 C), benefitted from the novel architecture of graphene-embedded Co 3 O 4 rose-spheres. This work has demonstrated a feasible strategy to improve the performance of Co 3 O 4 for lithium-ion battery application.

  13. Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters

    Science.gov (United States)

    Jiang, Fangming; Peng, Peng

    2016-01-01

    Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

  14. The concurrent validity of the technical test battery as an indicator of work performance in a telecommunications company

    Directory of Open Access Journals (Sweden)

    Marelize Barnard

    2005-10-01

    Full Text Available The purpose of this study was to assess the concurrent validity of the Technical Test Battery (TTB in a South African telecommunications institution. The Technical Test Battery (TTB was administered to a sample of 107 technical officers. Their test scores were compared to the scores obtained from a job performance rating scale specifically designed for this position on the basis of a thorough job analysis. The TTB demonstrated high concurrent validity as an indicator of work performance for technical posts in the telecommunications environment. These results suggest that the TTB may have a high predictive validity for performance in technical positions. The findings and implications of the study are discussed. Opsomming Die doel van hierdie studie was om die samevallende geldigheid van die “Technical Test Battery (TTB�? in ’n Suid-Afrikaanse telekommunikasie instansie te bepaal. Die TTB is op ’n steekproef van 107 tegniese personeel toegepas. Die toetstellings is in verband gebring met die tellings van ’n werksprestasiemaatstaf wat spesifiek vir die pos ontwikkel is op grond van ’n deeglike posanalise. Daar is bevind dat die TTB ’n hoë samevallende geldigheid as aanduider van werksprestasie vir tegniese poste in the telekommunikasiebedryf toon. Dié resultate dui op ’n sterk moontlikheid dat die TTB ’n goeie voorspeller van werksprestasie vir tegniese beroepe kan wees. Die bevindinge en implikasies van die studie word bespreek.

  15. Sulfurized carbon: a class of cathode materials for high performance lithium/sulfur batteries

    Directory of Open Access Journals (Sweden)

    Sheng S. Zhang

    2013-12-01

    Full Text Available Liquid electrolyte lithium/sulfur (Li/S batteries cannot come into practical applications because of many problems such as low energy efficiency, short cycle life, and fast self-discharge. All these problems are related to the dissolution of lithium polysulfide, a series of sulfur reduction intermediates, in the liquid electrolyte, and resulting parasitic reactions with the Li anode. Covalently binding sulfur onto carbon surface is a solution to completely eliminate the dissolution of lithium polysulfide and make the Li/S battery viable for practical applications. This can be achieved by replacing elemental sulfur with sulfurized carbon as the cathode material. This article reviews the current efforts on this subject and discusses the syntheses, electrochemical properties, and prospects of the sulfurized carbon as a cathode material in the rechargeable Li/S batteries.

  16. Preliminary study on zinc-carbon battery performance by using neutron tomography

    International Nuclear Information System (INIS)

    Abdul Aziz Mohamed; Nor Abidin Ashari; Mohd Zaid Abdullah; Junita Mohamad Saleh; Azraf Azman; Megat Harun AlRashid Megat Ahmad; Rafhayudi Jamro

    2008-08-01

    This paper describes on the discharging characteristic of zinc-carbon batteries (dry cells) by using a neutron imaging technique called a monochromatic neutron tomography. Experiment was conducted on the Nuclear Malaysia neutron tomography prototype instrument which based on 1-dimensional position sensitive neutron detector. The instrument is constructed at the small angle neutron scattering (SANS) beam line built at the one of the beam ports of TRIGA MARK II Research reactor, Malaysian Nuclear Agency, Bangi, Selangor. The main aim of this preliminary experiment was to test the instrument capability on a real industrial component. It was also aimed to understand structural and chemical changes of these battery particles after experiencing a discharging process. In this preliminary work, new and used batteries used were the products of Eveready company. (Author)

  17. One-Step Synthesis of Titanium Oxyhydroxy-Fluoride Rods and Research on the Electrochemical Performance for Lithium-ion Batteries and Sodium-ion Batteries.

    Science.gov (United States)

    Li, Biao; Gao, Zhan; Wang, Dake; Hao, Qiaoyan; Wang, Yan; Wang, Yongkun; Tang, Kaibin

    2015-12-01

    Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

  18. Carbon Nanotube Web with Carboxylated Polythiophene "Assist" for High-Performance Battery Electrodes.

    Science.gov (United States)

    Kwon, Yo Han; Park, Jung Jin; Housel, Lisa M; Minnici, Krysten; Zhang, Guoyan; Lee, Sujin R; Lee, Seung Woo; Chen, Zhongming; Noda, Suguru; Takeuchi, Esther S; Takeuchi, Kenneth J; Marschilok, Amy C; Reichmanis, Elsa

    2018-04-24

    A carbon nanotube (CNT) web electrode comprising magnetite spheres and few-walled carbon nanotubes (FWNTs) linked by the carboxylated conjugated polymer, poly[3-(potassium-4-butanoate) thiophene] (PPBT), was designed to demonstrate benefits derived from the rational consideration of electron/ion transport coupled with the surface chemistry of the electrode materials components. To maximize transport properties, the approach introduces monodispersed spherical Fe 3 O 4 (sFe 3 O 4 ) for uniform Li + diffusion and a FWNT web electrode frame that affords characteristics of long-ranged electronic pathways and porous networks. The sFe 3 O 4 particles were used as a model high-capacity energy active material, owing to their well-defined chemistry with surface hydroxyl (-OH) functionalities that provide for facile detection of molecular interactions. PPBT, having a π-conjugated backbone and alkyl side chains substituted with carboxylate moieties, interacted with the FWNT π-electron-rich and hydroxylated sFe 3 O 4 surfaces, which enabled the formation of effective electrical bridges between the respective components, contributing to efficient electron transport and electrode stability. To further induce interactions between PPBT and the metal hydroxide surface, polyethylene glycol was coated onto the sFe 3 O 4 particles, allowing for facile materials dispersion and connectivity. Additionally, the introduction of carbon particles into the web electrode minimized sFe 3 O 4 aggregation and afforded more porous FWNT networks. As a consequence, the design of composite electrodes with rigorous consideration of specific molecular interactions induced by the surface chemistries favorably influenced electrochemical kinetics and electrode resistance, which afforded high-performance electrodes for battery applications.

  19. Safety and performance of a long life lithium-thionyl chloride battery

    Energy Technology Data Exchange (ETDEWEB)

    Cieslak, W.R.; Street, H.K.

    1992-12-31

    We have developed a Li/SOCl{sub 2} ``D`` cell for applications requiring 10 to 15 years life at very low drain rates, typically less than 150 {mu}A. Maximizing cell safety and reliability, while delivering very good energy density, have been the goals of our study. We have achieved these goals by designing the cell to be application specific. The low-rate cell has been optimized to deliver up to 16 Ah at drain rates of less than 70 mA. By virtue of its low surface area, 145 cm{sub 2}, the cell has demonstrated excellent safety behavior. Safety testing has been performed on individual cells as well as on two-cell and four-cell batteries. Single cells did not vent when short-circuited. We were able to produce benign venting in a two cell string, but only when the string was partially discharged before shorting. The vent mechanism is a 300 psi rupture pressure burst disc manufactured by BS&B Safety Systems. We define benign venting as full opening of the 3/8 in. dia vent hole without deformation of the case. Material is expelled from the cell without flame, and the cell stack remains largely intact. We have not produced venting of the Sandia-designed low rate cell under any other abuse test conditions. The vent functions as an ultimate safety mechanism in the case of severe abuse, but resistance to venting under normal use and mild abuse conditions is key to the achievement of high reliability.

  20. Safety and performance of a long life lithium-thionyl chloride battery

    Energy Technology Data Exchange (ETDEWEB)

    Cieslak, W.R.; Street, H.K.

    1992-01-01

    We have developed a Li/SOCl[sub 2] D'' cell for applications requiring 10 to 15 years life at very low drain rates, typically less than 150 [mu]A. Maximizing cell safety and reliability, while delivering very good energy density, have been the goals of our study. We have achieved these goals by designing the cell to be application specific. The low-rate cell has been optimized to deliver up to 16 Ah at drain rates of less than 70 mA. By virtue of its low surface area, 145 cm[sub 2], the cell has demonstrated excellent safety behavior. Safety testing has been performed on individual cells as well as on two-cell and four-cell batteries. Single cells did not vent when short-circuited. We were able to produce benign venting in a two cell string, but only when the string was partially discharged before shorting. The vent mechanism is a 300 psi rupture pressure burst disc manufactured by BS B Safety Systems. We define benign venting as full opening of the 3/8 in. dia vent hole without deformation of the case. Material is expelled from the cell without flame, and the cell stack remains largely intact. We have not produced venting of the Sandia-designed low rate cell under any other abuse test conditions. The vent functions as an ultimate safety mechanism in the case of severe abuse, but resistance to venting under normal use and mild abuse conditions is key to the achievement of high reliability.

  1. Biofuel production system with operation flexibility: Evaluation of economic and environmental performance under external disturbance

    Science.gov (United States)

    Kou, Nannan

    Biomass derived liquid hydrocarbon fuel (biofuel) has been accepted as an effective way to mitigate the reliance on petroleum and reduce the greenhouse gas emissions. An increasing demand for second generation biofuels, produced from ligno-cellulosic feedstock and compatible with current infrastructure and vehicle technologies, addresses two major challenges faced by the current US transportation sector: energy security and global warming. However, biofuel production is subject to internal disturbances (feedstock supply and commodity market) and external factors (energy market). The biofuel industry has also heavily relied on government subsidy during the early development stages. In this dissertation, I investigate how to improve the economic and environmental performance of biorefineries (and biofuel plant), as well as enhance its survivability under the external disturbances. Three types of disturbance are considered: (1) energy market fluctuation, (2) subsidy policy uncertainty, and (3) extreme weather conditions. All three factors are basically volatile, dynamic, and even unpredictable, which makes them difficult to model and have been largely ignored to date. Instead, biofuel industry and biofuel research are intensively focused on improving feedstock conversion efficiency and capital cost efficiency while assuming these advancements alone will successfully generate higher profit and thus foster the biofuel industry. The collapse of the largest corn ethanol biofuel company, Verasun Energy, in 2008 calls into question this efficiency-driven approach. A detailed analysis has revealed that although the corn ethanol plants operated by Verasun adopted the more efficient (i.e. higher ethanol yield per bushel of corn and lower capital cost) dry-mill technology, they could not maintain a fair profit margin under fluctuating market condition which made ethanol production unprofitable. This is because dry-mill plant converts a single type of biomass feedstock (corn

  2. Microwave exfoliated graphene oxide/TiO{sub 2} nanowire hybrid for high performance lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Ishtiaque Shuvo, Mohammad Arif; Rodriguez, Gerardo; Karim, Hasanul; Lin, Yirong [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States); Islam, Md Tariqul; Noveron, Juan C. [Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968 (United States); Ramabadran, Navaneet [Department of Chemical Engineering, University of California at Santa Barbara, California 93106 (United States)

    2015-09-28

    Lithium ion battery (LIB) is a key solution to the demand of ever-improving, high energy density, clean-alternative energy systems. In LIB, graphite is the most commonly used anode material; however, lithium-ion intercalation in graphite is limited, hindering the battery charge rate and capacity. To date, one of the approaches in LIB performance improvement is by using porous carbon (PC) to replace graphite as anode material. PC's pore structure facilitates ion transport and has been proven to be an excellent anode material candidate in high power density LIBs. In addition, to overcome the limited lithium-ion intercalation obstacle, nanostructured anode assembly has been extensively studied to increase the lithium-ion diffusion rate. Among these approaches, high specific surface area metal oxide nanowires connecting nanostructured carbon materials accumulation have shown promising results for enhanced lithium-ion intercalation. Herein, we demonstrate a hydrothermal approach of growing TiO{sub 2} nanowires (TON) on microwave exfoliated graphene oxide (MEGO) to further improve LIB performance over PC. This MEGO-TON hybrid not only uses the high surface area of MEGO but also increases the specific surface area for electrode–electrolyte interaction. Therefore, this new nanowire/MEGO hybrid anode material enhances both the specific capacity and charge–discharge rate. Scanning electron microscopy and X-ray diffraction were used for materials characterization. Battery analyzer was used for measuring the electrical performance of the battery. The testing results have shown that MEGO-TON hybrid provides up to 80% increment of specific capacity compared to PC anode.

  3. Externally induced frontoparietal synchronization modulates network dynamics and enhances working memory performance.

    Science.gov (United States)

    Violante, Ines R; Li, Lucia M; Carmichael, David W; Lorenz, Romy; Leech, Robert; Hampshire, Adam; Rothwell, John C; Sharp, David J

    2017-03-14

    Cognitive functions such as working memory (WM) are emergent properties of large-scale network interactions. Synchronisation of oscillatory activity might contribute to WM by enabling the coordination of long-range processes. However, causal evidence for the way oscillatory activity shapes network dynamics and behavior in humans is limited. Here we applied transcranial alternating current stimulation (tACS) to exogenously modulate oscillatory activity in a right frontoparietal network that supports WM. Externally induced synchronization improved performance when cognitive demands were high. Simultaneously collected fMRI data reveals tACS effects dependent on the relative phase of the stimulation and the internal cognitive processing state. Specifically, synchronous tACS during the verbal WM task increased parietal activity, which correlated with behavioral performance. Furthermore, functional connectivity results indicate that the relative phase of frontoparietal stimulation influences information flow within the WM network. Overall, our findings demonstrate a link between behavioral performance in a demanding WM task and large-scale brain synchronization.

  4. A concept of external aerodynamic elements in improving the performance of natural smoke ventilation in wind conditions

    Science.gov (United States)

    Wegrzyński, Wojciech; Krajewski, Grzegorz; Kimbar, Grzegorz

    2018-01-01

    This paper is a proposal of a new device that may be used as a component of natural smoke ventilation systems - an external aerodynamic baffle used to limit the wind effect at the most adverse angle. Natural ventilation is not only affected by the external wind, but also dependent on the angle of wind attack. It has been proven, that at angles between 45° to 60° the performance of such device is the lowest. This is the reason why additional device is proposed - external baffle that could hypothetically increase the performance at chosen angles. The purpose of this paper is to explore this idea by numerical modelling of such external elements on a validated natural ventilator model, with use of ANSYS® Fluent® CFD model.

  5. Three dimensional Graphene aerogels as binder-less, freestanding, elastic and high-performance electrodes for lithium-ion batteries

    Science.gov (United States)

    Chen, Zhihang; Li, Hua; Tian, Ran; Duan, Huanan; Guo, Yiping; Chen, Yujie; Zhou, Jie; Zhang, Chunmei; DUGNANI, Roberto; Liu, Hezhou

    2016-01-01

    In this work it is shown how porous graphene aerogels fabricated by an eco-friendly and simple technological process, could be used as electrodes in lithium- ion batteries. The proposed graphene framework exhibited excellent performance including high reversible capacities, superior cycling stability and rate capability. A significantly lower temperature (75 °C) than the one currently utilized in battery manufacturing was utilized for self-assembly hence providing potential significant savings to the industrial production. After annealing at 600 °C, the formation of Sn-C-O bonds between the SnO2 nanoparticles and the reduced graphene sheets will initiate synergistic effect and improve the electrochemical performance. The XPS patterns revealed the formation of Sn-C-O bonds. Both SEM and TEM imaging of the electrode material showed that the three dimensional network of graphene aerogels and the SnO2 particles were distributed homogeneously on graphene sheets. Finally, the electrochemical properties of the samples as active anode materials for lithium-ion batteries were tested and examined by constant current charge–discharge cycling and the finding fully described in this manuscript. PMID:27265146

  6. Effect of Nickel Coated Multi-Walled Carbon Nanotubes on Electrochemical Performance of Lithium-Sulfur Rechargeable Batteries.

    Science.gov (United States)

    Wu, Xiao; Yao, Shanshan; Hou, Jinli; Jing, Maoxiang; Qian, Xinye; Shen, Xiangqian; Xiang, Jun; Xi, Xiaoming

    2017-04-01

    Conventional lithium-sulfur batteries suffer from severe capacity fade, which is induced by low electron conductivity and high dissolution of intermediated polysulfides. Recent studies have shown the metal (Pt, Au, Ni) as electrocatalyst of lithium polysulfides and improved the performance for lithium sulfur batteries. In this work, we present the nickel coated multi-walled carbon nanotubes (Ni-MWNTs) as additive materials for elemental sulfur positive electrodes for lithium-sulfur rechargeable batteries. Compared with MWNTs, the obtained Ni-MWNTs/sulfur composite cathode demonstrate a reversible specific capacity approaching 545 mAh after 200 cycles at a rate of 0.5C as well as improved cycling stability and excellent rate capacity. The improved electrochemical performance can be attributed to the fact the MWNTs shows a vital role on polysulfides adsorption and nickel has a catalytic effect on the redox reactions during charge–discharge process. Meanwhile, the Ni-MWNTs is a good electric conductor for sulfur cathode.

  7. Electrodeposited Structurally Stable V2O5 Inverse Opal Networks as High Performance Thin Film Lithium Batteries.

    Science.gov (United States)

    Armstrong, Eileen; McNulty, David; Geaney, Hugh; O'Dwyer, Colm

    2015-12-09

    High performance thin film lithium batteries using structurally stable electrodeposited V2O5 inverse opal (IO) networks as cathodes provide high capacity and outstanding cycling capability and also were demonstrated on transparent conducting oxide current collectors. The superior electrochemical performance of the inverse opal structures was evaluated through galvanostatic and potentiodynamic cycling, and the IO thin film battery offers increased capacity retention compared to micron-scale bulk particles from improved mechanical stability and electrical contact to stainless steel or transparent conducting current collectors from bottom-up electrodeposition growth. Li(+) is inserted into planar and IO structures at different potentials, and correlated to a preferential exposure of insertion sites of the IO network to the electrolyte. Additionally, potentiodynamic testing quantified the portion of the capacity stored as surface bound capacitive charge. Raman scattering and XRD characterization showed how the IO allows swelling into the pore volume rather than away from the current collector. V2O5 IO coin cells offer high initial capacities, but capacity fading can occur with limited electrolyte. Finally, we demonstrate that a V2O5 IO thin film battery prepared on a transparent conducting current collector with excess electrolyte exhibits high capacities (∼200 mAh g(-1)) and outstanding capacity retention and rate capability.

  8. The origin of the enhanced performance of nitrogen-doped MoS_2 in lithium ion batteries

    International Nuclear Information System (INIS)

    Liu, Qiuhong; Weijun, Xia; Wu, Zhenjun; Huo, Jia; Liu, Dongdong; Wang, Shuangyin; Wang, Qiang

    2016-01-01

    MoS_2 with a similar layered structure to graphene has been widely applied in various areas including lithium ion batteries. However, low conductivity, capacity fading and poor rate performance are still the main challenges for MoS_2 anode materials. In this work, for the first time, we prepared nitrogen-doped MoS_2 (N-MoS_2) nanosheets through a simple two-step method involving the preparation of MoS_2 with defects by the hydrothermal method, followed by sintering in a NH_3 atmosphere. Our electrochemical characterizations and density functional theory calculations demonstrated that nitrogen doping could enhance the electron conductivity and showed higher specific capacity than pristine MoS_2 as anode materials of lithium ion batteries, which can be attributed to the faster transportation of electrons and ions because of nitrogen doping. This work helps us understand the origin of the enhanced performance of N-doped MoS_2 in lithium ion batteries. (paper)

  9. Synthesis and performances of Li-Rich@AlF3@Graphene as cathode of lithium ion battery

    International Nuclear Information System (INIS)

    Chen, Dongrui; Tu, Wenqiang; Chen, Min; Hong, Pengbo; Zhong, Xiaoxin; Zhu, Yunmin; Yu, Qipeng; Li, Weishan

    2016-01-01

    Highlights: • Li-Rich@AlF 3 @Graphene was developed as cathode of lithium ion battery. • Coating of 2 nm AlF 3 does not cause capacity loss but is beneficial to rate capability. • Concurrent AlF 3 coating and graphene wrapping significantly improve Li-Rich performance. - Abstract: A novel composite of layered lithium-rich oxide with AlF 3 and graphene, Li-Rich@AlF 3 @Graphene, is synthesized as high performance cathode of lithium ion battery in terms of rate capability and cyclic stability. Physical characterizations from X-ray diffraction, scanning electron microscope and transmission electron microscope, demonstrate that the layered lithium-rich oxide in Li-Rich@AlF 3 @Graphene is composed of uniform nanoparticles of 100 nm, which are coated with a layer of 2 nm AlF 3 and wrapped with graphene sheets. Charge/discharge tests indicate that the naked lithium-rich oxide exhibits poor cyclic stability and rate capability as cathode of lithium ion battery, which can be improved to some extent by the only contribution of AlF 3 but significantly by the concurrent contribution of AlF 3 and graphene.

  10. Flexible one-dimensional carbon-selenium composite nanofibers with superior electrochemical performance for Li-Se/Na-Se batteries

    Science.gov (United States)

    Zeng, Linchao; Wei, Xiang; Wang, Jiaqing; Jiang, Yu; Li, Weihan; Yu, Yan

    2015-05-01

    A facile strategy is developed to synthesis selenium/carbon composites (Se@CNFs-CNT) by co-heating Se powder and electrospun Polyacrylonitrile (PAN)-CNT nanofibers at 600°Cin a sealed vessel. The Se molecules are chemically bonded and physical encapsulated by carbonized PAN-CNT composite (CNFs-CNT), which leads to prevent the dissolution of polyselenide intermediates in carbonate based electrolyte. When directly used as flexible free-standing cathode material for Li-Se batteries in low cost carbonate-based electrolyte, the Se@CNFs-CNT electrode exhibits improved cyclability (517 mAh g-1 after 500 cycles at 0.5 A g-1) and rate capability (485 mAh g-1 at 1 A g-1). Moreover, when tested as sodium batteries, it maintains a reversible capacity of 410 mAh g-1 after 240 cycles at 0.5 A g-1. The superior electrochemical performance (especially at high rates) of Se@CNFs-CNT is attributed to synergistic effect of the additive of CNT, the well confine of Se in the CNFs-CNT matrix through chemical bonding and the 3D interconnected carbon nanofibers (CNFs). This simple yet efficient process thus provides a promising route towards fabrication of a variety of high performance flexible Li-Se and Na-Se batteries.

  11. Synthesis and electrochemical performances of amorphous carbon-coated Sn Sb particles as anode material for lithium-ion batteries

    Science.gov (United States)

    Wang, Zhong; Tian, Wenhuai; Liu, Xiaohe; Yang, Rong; Li, Xingguo

    2007-12-01

    The amorphous carbon coating on the Sn-Sb particles was prepared from aqueous glucose solutions using a hydrothermal method. Because the outer layer carbon of composite materials is loose cotton-like and porous-like, it can accommodate the expansion and contraction of active materials to maintain the stability of the structure, and hinder effectively the aggregation of nano-sized alloy particles. The as-prepared composite materials show much improved electrochemical performances as anode materials for lithium-ion batteries compared with Sn-Sb alloy and carbon alone. This amorphous carbon-coated Sn-Sb particle is extremely promising anode materials for lithium secondary batteries and has a high potentiality in the future use.

  12. High-performance graphene/sulphur electrodes for flexible Li-ion batteries using the low-temperature spraying method

    Science.gov (United States)

    Kumar, Pushpendra; Wu, Feng-Yu; Hu, Lung-Hao; Ali Abbas, Syed; Ming, Jun; Lin, Chia-Nan; Fang, Jason; Chu, Chih-Wei; Li, Lain-Jong

    2015-04-01

    Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become a crucial and new focus of S-based Li-ion batteries. Herein, we propose to use a low temperature spraying process to fabricate graphene/S electrode material, where the ink is composed of graphene flakes and the micron-sized S particles prepared by grinding of low-cost S powders. The S particles are found to be well hosted by highly conductive graphene flakes and consequently superior cyclability (~70% capacity retention after 250 cycles), good coulombic efficiency (~98%) and high capacity (~1500 mA h g-1) are obtained. The proposed approach does not require high temperature annealing or baking; hence, another great advantage is to make flexible Li-ion batteries. We have also demonstrated two types of flexible batteries using sprayed graphene/S electrodes.Elementary sulphur (S) has been shown to be an excellent cathode material in energy storage devices such as Li-S batteries owing to its very high capacity. The major challenges associated with the sulphur cathodes are structural degradation, poor cycling performance and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling. Tremendous efforts made by others have demonstrated that encapsulation of S materials improves their cycling performance. To make this approach practical for large scale applications, the use of low-cost technology and materials has become

  13. Electrochemically Formed Ultrafine Metal Oxide Nanocatalysts for High-Performance Lithium–Oxygen Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Yan, Pengfei; Xu, Wu; Zheng, Jianming; He, Yang; Luo, Langli; Bowden, Mark E.; Wang, Chong-Min; Zhang, Ji-Guang

    2016-08-10

    Lithium-oxygen (Li-O2) battery has an extremely high theoretical specific energy density as compared with conventional energy storage systems. However, practical application of Li-O2 battery system still faces significant challenges, especially its poor cyclability. In this work, we report a new approach to synthesis ultrafine metal oxide nanocatalysts through an electrochemical pre-lithiation process. This process reduces the size of NiCo2O4 (NCO) particles from 20~30 nm to a uniformly distributed domain of ~ 2 nm and largely improved their catalytic activity. Structurally, the pre-lithiated NCO NWs are featured by ultrafine NiO/CoO nanoparticles, which show high stability during prolonged cycles in terms of morphology and the particle size, therefore maintaining an excellent catalytic effect to oxygen reduction and evolution reactions. Li-O2 battery using this catalyst has demonstrated an initial capacity of 29,280 mAh g-1 and has retained a stable capacity of over 1,000 mAh g-1 after 100 cycles based on the weight of NCO active material. Direct in-situ TEM observation conclusively reveals the lithiation/delithiation process of as-prepared NCO NWs, clarifying the NCO/Li electrochemical reaction mechanism that can be extended to other transition-metal oxides and providing the in depth understandings on the catalysts and battery chemistries of other ternary transition-metal oxides.

  14. Human Performance Task Batteries and Models: An Abilities-Based Directory

    Science.gov (United States)

    1986-12-01

    8217. BATTERY/TASKLS^ f^ODELYS^ none located to date Sanders Stamina The ability to withstand considerable physical exertion without becoming winded or...Tha Frnfi Pmsg I Jerison, H.J. & Arginteau, J. (1958). Time judgment, acoustic noise and judgement drift (Technical Report No. 57-474). Dayton, OH

  15. Improving the performance of si-based li-ion battery anodes by utilizing phosphorene encapsulation

    NARCIS (Netherlands)

    Peng, B.; Xu, Y.; Mulder, F.M.

    2017-01-01

    Si-based anode materials in Li-ion batteries (LIBs) suffer from severe volume expansion/contraction during repetitive discharge/charge, which results in the pulverization of active materials, continuous growth of solid electrolyte interface (SE!) layers, loss of electrical conduction, and,

  16. Control mechanisms for battery energy storage system performing primary frequency regulation and self-consumption optimization

    NARCIS (Netherlands)

    Pliatskas Stylianidis, A.

    2016-01-01

    This report contains the design of a model for the integration of a battery energy system in a household level and its use for primary frequency regulation and self-consumption optimization. The main goal of this project was to investigate what are the possible applications and the most suitable for

  17. Performance of External Quality Control Reviews by Military Department Audit Agencies

    National Research Council Canada - National Science Library

    Berry, Wayne

    2000-01-01

    The Government auditing standards issued by the Comptroller General of the United States require organizations conducting audits in accordance with Government auditing standards to undergo an external...

  18. Superior lithium storage performance of hierarchical porous vanadium pentoxide nanofibers for lithium ion battery cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Bo [Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); National Key Laboratory of Power Sources, Tianjin Institute of Power Sources, Tianjin 300381 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Bai, Zhimin, E-mail: zhimibai@cugb.edu.cn [Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Li, Minsi [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Dong, Lei; Xiong, Dongbin [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Dejun, E-mail: dejunli@mail.tjnu.edu.cn [Energy & Materials Engineering Centre, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China)

    2015-06-15

    Highlights: • Hierarchical porous vanadium pentoxide nanofibers were synthesized by electrospinning. • V{sub 2}O{sub 5} nanofibers showed much enhanced lithium storage performance. • Kinetics process of electrospinning V{sub 2}O{sub 5} nanofibers was studied by means of EIS for the first time. • Strategies to enhance the electrochemical performance of V{sub 2}O{sub 5} electrode were concluded. - Abstract: The hierarchical V{sub 2}O{sub 5} nanofibers cathode materials with diameter of 200–400 nm are successfully synthesized via an electrospinning followed by annealing. Powder X-ray diffraction (XRD) pattern confirms the formation of phase-pure product. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) obviously display the hierarchical porous nanofibers constructed by attached tiny vanadium oxide nanoplates. Electrochemical behavior of the as-prepared product is systematically studied using galvanostatic charge/discharge testing, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). It turns out that in comparison to the commercial V{sub 2}O{sub 5} and other unique nanostructured materials in the literature, our V{sub 2}O{sub 5} nanofibers show much enhanced lithium storage capacity, improved cyclic stability, and higher rate capability. After 100 cycles at a current density of 800 mA g{sup −1}, the specific capacity of the V{sub 2}O{sub 5} nanofibers retain 133.9 mAh g{sup −1}, corresponding to high capacity retention of 96.05%. More importantly, the EIS at various discharge depths clearly reveal the kinetics process of the V{sub 2}O{sub 5} cathode reaction with lithium. Based on our results, the possible approach to improve the specific capacity and rate capability of the V{sub 2}O{sub 5} cathode material is proposed. It is expected that this study could accelerate the development of V{sub 2}O{sub 5} cathode in rechargeable lithium ion batteries.

  19. The influence of age, gender and education on the performance of healthy individuals on a battery for assessing limb apraxia

    Directory of Open Access Journals (Sweden)

    Joana Mantovani-Nagaoka

    Full Text Available ABSTRACT Introduction: Apraxia is defined as a disorder of learned skilled movements, in the absence of elementary motor or sensory deficits and general cognitive impairment, such as inattention to commands, object-recognition deficits or poor oral comprehension. Limb apraxia has long been a challenge for clinical assessment and understanding and covers a wide spectrum of disorders, all involving motor cognition and the inability to perform previously learned actions. Demographic variables such as gender, age, and education can influence the performance of individuals on different neuropsychological tests. Objective: The present study aimed to evaluate the performance of healthy subjects on a limb apraxia battery and to determine the influence of gender, age, and education on the praxis skills assessed. Methods: Forty-four subjects underwent a limb apraxia battery, which was composed of numerous subtests for assessing both the semantic aspects of gestural production as well as motor performance itself. The tasks encompassed lexical-semantic aspects related to gestural production and motor activity in response to verbal commands and imitation. Results: We observed no gender effects on any of the subtests. Only the subtest involving visual recognition of transitive gestures showed a correlation between performance and age. However, we observed that education level influenced subject performance for all sub tests involving motor actions, and for most of these, moderate correlations were observed between education level and performance of the praxis tasks. Conclusion: We conclude that the education level of participants can have an important influence on the outcome of limb apraxia tests.

  20. Performance of an automated external defibrillator in a moving ambulance vehicle.

    Science.gov (United States)

    Yun, Jong Geun; Jeung, Kyung Woon; Lee, Byung Kook; Ryu, Hyun Ho; Lee, Hyoung Youn; Kim, Mu Jin; Heo, Tag; Min, Yong Il; You, Yeonho

    2010-04-01

    The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport. An ambulance was driven on paved (20-100 km/h) and unpaved (10 km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5-5m/s(2)) measured by the vibrometer in the previous phase of the investigation. The vibration intensity increased with increasing speeds on paved roads (1.98+/-0.44 m/s(2) at 100 km/h). While driving on unpaved roads, it increased to 6.40+/-1.06 m/s(2). Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5-1m/s(2), which corresponded to vibration intensities while driving on paved roads at 20-60 km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms. Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  1. In Situ formation of pentafluorophosphate benzimidazole anion stabilizes high-temperature performance of lithium-ion batteries

    International Nuclear Information System (INIS)

    Pradanawati, Sylvia Ayu; Wang, Fu-Ming; Rick, John

    2014-01-01

    Highlights: • A new pentafluorophosphate benzimidazole anion was formed by Lewis acid-base reaction. • This pentafluorophosphate benzimidazole anion is fabricated with the benzimidazole anion and PF 5 . • This pentafluorophosphate benzimidazole anion avoids the ominous side reactions that PF 5 reacts SEI to form LiF and HF at high temperature. • The additional pentafluorophosphate benzimidazole anion formation well maintains the battery performance at 60 °C measurement compares to the electrolyte only with contains the salt, LiPF 6 . - Abstract: Lithium salts play a critical role in initiating electrochemical reactions in Li-ion batteries. Single Li ions dissociate from bulk-salt and associate with carbonates to form a solid electrolyte interface (SEI) during the first charge-discharge of the battery. SEI formation and the chemical stability of salt must both be controlled and optimized to minimize irreversible reactions in SEI formation and to suppress the decomposition of the salt at high temperatures. This study synthesizes a new benzimidazole-based anion in the electrolyte. This anion, pentafluorophosphate benzimidazole, results from a Lewis acid-base reaction between the benzimidazole anion and PF 5 . The new pentafluorophosphate benzimidazole anion inhibits the decomposition of LiPF 6 by inhibiting PF 5 side reactions, which degrade the SEI, and lead to the formation of LiF and HF at high temperatures. In addition, the use of the pentafluorophosphate benzimidazole anion results in the formation of a modified SEI that is able to modify the battery's performance. Cyclic voltammetry, scanning electron microscopy, differential scanning calorimetry, electrochemical impedance spectroscopy, as well as charge-discharge and X-ray photoelectron spectroscopy measurements have been used to characterize the materials in this study. The formation of the pentafluorophosphate benzimidazole anion in the electrolyte caused a 14% decrease in the activation energy

  2. Performance of Mg-14Li-1Al-0.1Ce as anode for Mg-air battery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yibin; Li, Deyu [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Li, Ning [School of Chemical Engineering and Technology, Harbin Institute of Technology, West Street No. 92, Harbin 150001 (China); Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China); Zhang, Milin; Huang, Xiaomei [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001 (China)

    2011-02-15

    In this research, a new Mg-air battery based on Mg-14Li-1Al-0.1Ce was prepared and the battery performance was investigated by constant current discharge test. The corrosion behavior of Mg, AZ31 and Mg-Li-Al-Ce were studied by self-corrosion rate measurement and potentiodynamic polarization measurement. The characteristics of Mg-Li-Al-Ce after discharge were investigated by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results show that Mg-Li-Al-Ce is more active than Mg and AZ31. The self-corrosion rate is found to be in the order: Mg-Li-Al-Ce < Mg < AZ31. It has been observed that the Mg-air battery based on Mg-Li-Al-Ce offers higher operating voltage, anodic efficiency and capacity than those with Mg and AZ31. SEM and EIS results show that the discharge product of Mg-Li-Al-Ce is loosely adhered to the alloy surface, and thus Mg-Li-Al-Ce could keep high discharge activity during discharge. (author)

  3. Hierarchical N-Rich Carbon Sponge with Excellent Cycling Performance for Lithium-Sulfur Battery at High Rates.

    Science.gov (United States)

    Zhen, Mengmeng; Wang, Juan; Wang, Xin; Wang, Cheng

    2018-04-17

    Lithium-sulfur batteries (LSBs) are receiving extensive attention because of their high theoretical energy density. However, practical applications of LSBs are still hindered by their rapid capacity decay and short cycle life, especially at high rates. Herein, a highly N-doped (≈13.42 at %) hierarchical carbon sponge (HNCS) with strong chemical adsorption for lithium polysulfide is fabricated through a simple sol-gel route followed by carbonization. Upon using the HNCS as the sulfur host material in the cathode and an HNCS-coated separator, the battery delivers an excellent cycling stability with high specific capacities of 424 and 326 mA h g -1 and low capacity fading rates of 0.033 % and 0.030 % per cycle after 1000 cycles under high rates of 5 and 10 C, respectively, which are superior to those of other reported carbonaceous materials. These impressive cycling performances indicate that such a battery could promote the practical application prospects of LSBs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Flexible Overoxidized Polypyrrole Films with Orderly Structure as High-Performance Anodes for Li- and Na-Ion Batteries.

    Science.gov (United States)

    Yuan, Tao; Ruan, Jiafeng; Zhang, Weimin; Tan, Zhuopeng; Yang, Junhe; Ma, Zi-Feng; Zheng, Shiyou

    2016-12-28

    Flexible polypyrrole (PPy) films with highly ordered structures were fabricated by a novel vapor phase polymerization (VPP) process and used as the anode material in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The PPy films demonstrate excellent rate performance and cycling stability. At a charge/discharge rate of 1 C, the reversible capacities of the PPy film anode reach 284.9 and 177.4 mAh g -1 in LIBs and SIBs, respectively. Even at a charge/discharge rate of 20 C, the reversible capacity of the PPy film anode retains 54.0% and 52.9% of the capacity of 1 C in LIBs and SIBs, respectively. After 1000 electrochemical cycles at a rate of 10 C, there is no obvious capacity fading. The molecular structure and electrochemical behaviors of Li- and Na-ion doping and dedoping in the PPy films are investigated by XPS and ex situ XRD. It is believed that the PPy film electrodes in the overoxidized state can be reversibly charged and discharged through the doping and dedoping of lithium or sodium ions. Because of the self-adaptation of the doped ions, the ordered pyrrolic chain structure can realize a fast charge/discharge process. This result may substantially contribute to the progress of research into flexible polymer electrodes in various types of batteries.

  5. A mesoporous WO3−X/graphene composite as a high-performance Li-ion battery anode

    International Nuclear Information System (INIS)

    Liu, Fei; Kim, Jong Gu; Lee, Chul Wee; Im, Ji Sun

    2014-01-01

    Graphical abstract: The highly flexible and conductive graphene layer can enhance electron transfer, protect metal oxides against disintegration and aggregation and buffer the strain induced by volume expansion during cycles. The mesoporous surface layer provides an open network for Li+ diffusion. - Highlights: • Novel cocktail effects of 2D mesoporous WO 3−X /graphene for lithium ion battery. • New approach for lithium ion battery by easy and unique synthesis method. • Mechanism study with proper data for understanding a reaction on anode surface. - Abstract: A novel mesoporous WO 3−X /graphene composite was developed. This material allowed rapid electron and Li + ion diffusion when used as a Li-ion battery (LIB) anode material. Remarkably, the graphene support protected WO 3−X from changing volume during the electrochemical cycling process; this process generally induces capacity loss. The current work describes a high-performance anode material for LIB that has highly dense WO 3−X , as well as high capacity, rate capability and stability

  6. One Step Hydrothermal Synthesis of FeCO3 Cubes for High Performance Lithium-ion Battery Anodes

    International Nuclear Information System (INIS)

    Zhang, Congcong; Liu, Weijian; Chen, Dongyang; Huang, Jiayi; Yu, Xiaoyuan; Huang, Xueyan; Fang, Yueping

    2015-01-01

    Highlights: • FeCO 3 nanocubes with edge length of ∼300 nm were prepared. • A reversible capacity of 761 mAh g −1 was achieved at 200 mA g −1 after 130 cycles. • Cyclic voltammetry and electrochemical impedance were employed to understand the cell performances. - Abstract: Uniform FeCO 3 cubes with edge length of ∼300 nm were prepared by a facile one-step hydrothermal reaction and studied as anode material for lithium-ion batteries. Interestingly, the FeCO 3 anode has an extremely high initial specific capacity of 1796 mAh g −1 . After cycling at a current rate of 200 mA g −1 for 130 cycles, an excellent discharge capacity of 761 mAh g −1 is still maintained. Moreover, the FeCO 3 anode exhibits significant high-rate capability, e.g., ∼430 mAh g −1 is obtained at a current rate of 1200 mA g −1 . The observation of the FeCO 3 cubes represents an important development of realizing both high capacity and good cycleability in conversion type anode materials for lithium-ion battery at the same time. Such cheap, easy-to-make, and environmentally benign material is promising for practical deployment for lithium ion batteries anode.

  7. Performance Comparison of Rechargeable Batteries for Stationary Applications (Ni/MH vs. Ni–Cd and VRLA)

    OpenAIRE

    Michael A. Zelinsky; John M. Koch; Kwo-Hsiung Young

    2017-01-01

    The stationary power market, particularly telecommunications back-up (telecom) applications, is dominated by lead-acid batteries. A large percentage of telecom powerplants are housed in outdoor enclosures where valve-regulated lead-acid (VRLA) batteries are commonly used because of their low-maintenance design. Batteries in these enclosures can be exposed to temperatures which can exceed 70 °C, significantly reducing battery life. Nickel–cadmium (Ni–Cd) batteries have traditionally been deplo...

  8. High performance screen printable lithium-ion battery cathode ink based on C-LiFePO4

    International Nuclear Information System (INIS)

    Sousa, R.E.; Oliveira, J.; Gören, A.; Miranda, D.; Silva, M.M.; Hilliou, Loic; Costa, C.M.; Lanceros-Mendez, S.

    2016-01-01

    Highlights: • C-LiFePO 4 paste was been prepared for screen-printing technique. • The inks produced have a Newtonian viscosity of 3 Pa.s for this printing technique. • C-LiFePO 4 inks present a 48.2 mAh.g −1 after 50 cycles at 5C. • This ink is suitable in the development of printed lithium ion batteries. - Abstract: Lithium-ion battery cathodes have been fabricated by screen-printing through the development of C-LiFePO 4 inks. It is shown that shear thinning polymer solutions in N-methyl-2-pyrrolidone (NMP) with Newtonian viscosity above 0.4 Pa s are the best binders for formulating a cathode paste with satisfactory film forming properties. The paste shows an elasticity of the order of 500 Pa and, after shear yielding, shows an apparent viscosity of the order of 3 Pa s for shear rates corresponding to those used during screen-printing. The screen-printed cathode produced with a thickness of 26 μm shows a homogeneous distribution of the active material, conductive additive and polymer binder. The total resistance and diffusion coefficient of the cathode are ∼ 450 Ω and 2.5 × 10 −16 cm 2 s −1 , respectively. The developed cathodes show an initial discharge capacity of 48.2 mAh g −1 at 5C and a discharge value of 39.8 mAh g −1 after 50 cycles. The capacity retention of 83% represents 23% of the theoretical value (charge and/or discharge process in twenty minutes), demonstrating the good performance of the battery. Thus, the developed C-LiFePO 4 based inks allow to fabricate screen-printed cathodes suitable for printed lithium-ion batteries.

  9. Experimental investigation on the thermal performance of heat pipe-assisted phase change material based battery thermal management system

    International Nuclear Information System (INIS)

    Wu, Weixiong; Yang, Xiaoqing; Zhang, Guoqing; Chen, Kai; Wang, Shuangfeng

    2017-01-01

    Highlights: • A heat pipe assisted phase change material based battery thermal management system is proposed. • The proposed system is compact and efficient from a view of practical application. • Cycling conditions are experimentally simulated for practical working environment. • The proposed system presents better thermal performance in comparison to other systems. • Combining forced air convection with heat pipe further enhances the cooling effect. - Abstract: In this paper, a heat pipe-assisted phase change material (PCM) based battery thermal management (BTM) system is designed to fulfill the comprehensive energy utilization for electric vehicles and hybrid electric vehicles. Combining the large heat storage capacity of the PCM with the excellent cooling effect of heat pipe, the as-constructed heat pipe-assisted PCM based BTM is feasible and effective with a relatively longer operation time and more suitable temperature. The experimental results show that the temperature maldistribution of battery module can be influenced by heat pipes when they are activated under high discharge rates of the batteries. Moreover, with forced air convection, the highest temperature could be controlled below 50 °C even under the highest discharge rate of 5C and a more stable and lower temperature fluctuation is obtained under cycling conditions. Meanwhile, the effectiveness of further increasing air velocity (i.e., more fan power consumption) is limited when the highest temperature continues to reduce at a lower rate due to the phase transition process of PCM. These results are expected to provide insights into the design and optimization of BTM systems.

  10. A comparative study on electrochemical performances of the electrodes with different nanocarbon conductive additives for lithium ion batteries

    International Nuclear Information System (INIS)

    Chen, Taiqiang; Pan, Likun; Liu, Xinjuan; Sun, Zhuo

    2013-01-01

    Three nanocarbon materials (0 D acetylene black (AB), 1 D carbon nanotubes (CNTs) and 2 D reduced graphene oxide (RGO)) were used as conductive additives (CAs) in the mesocarbon microbead anodes for lithium ion batteries. The electrochemical performances of the electrodes were investigated. The results show that the CAs have a significant impact on the electrode performance because they can influence the electron conduction and lithium ion transportation within the electrode. The electrode with RGO achieves a maximum capacity of 387 mAh g −1 after 50 cycles at a current density of 50 mA g −1 , much higher than those of the electrodes with AB (334 mAh g −1 ) and CNTs (319 mAh g −1 ). The improvement should be mainly ascribed to the “plane-to-point” conducting network formed in the electrode with 2 D RGO which can favor the electron conduction and enhance the lithium ion transportation. - Highlights: • Three carbon materials were used as additives in the electrodes of Li ion battery. • The electrochemical performances of the electrodes were comparatively investigated. • The carbon additives have a significant impact on the electrode performance. • RGO additive acts as a bridge to form a “plane-to-point” conducting network. • The electrode with RGO exhibits better performance than those with other additives

  11. Thrust performance, propellant ionization, and thruster erosion of an external discharge plasma thruster

    Science.gov (United States)

    Karadag, Burak; Cho, Shinatora; Funaki, Ikkoh

    2018-04-01

    It is quite a challenge to design low power Hall thrusters with a long lifetime and high efficiency because of the large surface area to volume ratio and physical limits to the magnetic circuit miniaturization. As a potential solution to this problem, we experimentally investigated the external discharge plasma thruster (XPT). The XPT produces and sustains a plasma discharge completely in the open space outside of the thruster structure through a magnetic mirror configuration. It eliminates the very fundamental component of Hall thrusters, discharge channel side walls, and its magnetic circuit consists solely of a pair of hollow cylindrical permanent magnets. Thrust, low frequency discharge current oscillation, ion beam current, and plasma property measurements were conducted to characterize the manufactured prototype thruster for the proof of concept. The thrust performance, propellant ionization, and thruster erosion were discussed. Thrust generated by the XPT was on par with conventional Hall thrusters [stationary plasma thruster (SPT) or thruster with anode layer] at the same power level (˜11 mN at 250 W with 25% anode efficiency without any optimization), and discharge current had SPT-level stability (Δ design and provide a successful proof of concept experiment of the XPT.

  12. Performance of Retrofitted Self-Compacting Concrete-Filled Steel Tube Beams Using External Steel Plates

    Directory of Open Access Journals (Sweden)

    Ahmed A. M. AL-Shaar

    2018-01-01

    Full Text Available Self-compacting concrete-filled steel tube (SCCFST beams, similar to other structural members, necessitate retrofitting for many causes. However, research on SCCFST beams externally retrofitted by bolted steel plates has seldom been explored in the literature. This paper aims at experimentally investigating the retrofitting performance of square self-compacting concrete-filled steel tube (SCCFST beams using bolted steel plates with three different retrofitting schemes including varied configurations and two different steel plate lengths under flexure. A total of 18 specimens which consist of 12 retrofitted SCCFST beams, three unretrofitted (control SCCFST beams, and three hollow steel tubes were used. The flexural behaviour of the retrofitted SCCFST beams was examined regarding flexural strength, failure modes, and moment versus deflection curves, energy absorption, and ductility. Experimental results revealed that the implemented retrofitting schemes efficiently improve the moment carrying capacity and stiffness of the retrofitted SCCFST beams compared to the control beams. The increment in flexural strength ranged from 1% to 46%. Furthermore, the adopted retrofitting schemes were able to restore the energy absorption and ductility of the damaged beams in the range of 35% to 75% of the original beam ductility. Furthermore, a theoretical model was suggested to predict the moment capacity of the retrofitted SCCFST beams. The theoretical model results were in good agreement with the test results.

  13. Homing pigeons externally exposed to Deepwater Horizon crude oil change flight performance and behavior.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Cacela, Dave; Dean, Karen M; Pritsos, Chris A

    2017-11-01

    The Deepwater Horizon oil spill was the largest in U.S. history, contaminating thousands of miles of coastal habitat and affecting the lives of many avian species. The Gulf of Mexico is a critical bird migration route area and migrants that were oiled but did not suffer mortality as a direct result of the spill faced unpredictable fates. This study utilized homing pigeons as a surrogate species for migratory birds to investigate the effects a single low level external oiling event has on the flight performance and behavior of birds flying repeated 161 km flights. Data from GPS data loggers showed that lightly oiled pigeons changed their flight paths, increased their flight durations by 2.6 fold, increased their flight distances by 28 km and subsequently decreased their route efficiencies. Oiled birds also exhibited reduced rate of weight gain between flights. Our data suggest that contaminated birds surviving the oil spill may have experienced flight impairment and reduced refueling abilities, likely reducing overall migration speed. Our findings contribute new information on how oil spills affect avian species, as the effects of oil on the flight behavior of long distance free-flying birds have not been previously described. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. External quality assurance performance of clinical research laboratories in sub-saharan Africa.

    Science.gov (United States)

    Amukele, Timothy K; Michael, Kurt; Hanes, Mary; Miller, Robert E; Jackson, J Brooks

    2012-11-01

    Patient Safety Monitoring in International Laboratories (JHU-SMILE) is a resource at Johns Hopkins University that supports and monitors laboratories in National Institutes of Health-funded international clinical trials. To determine the impact of the JHU-SMILE quality assurance scheme in sub-Saharan African laboratories, we reviewed 40 to 60 months of external quality assurance (EQA) results of the College of American Pathologists (CAP) in these laboratories. We reviewed the performance of 8 analytes: albumin, alanine aminotransferase, creatinine, sodium, WBC, hemoglobin, hematocrit, and the human immunodeficiency virus antibody rapid test. Over the 40- to 60-month observation period, the sub-Saharan laboratories had a 1.63% failure rate, which was 40% lower than the 2011 CAP-wide rate of 2.8%. Seventy-six percent of the observed EQA failures occurred in 4 of the 21 laboratories. These results demonstrate that a system of remote monitoring, feedback, and audits can support quality in low-resource settings, even in places without strong regulatory support for laboratory quality.

  15. International Space Station Nickel-Hydrogen Battery Startup and Initial Performance

    Science.gov (United States)

    Dalton, Penni; Cohen, Fred; Hajela, Gyan

    2002-01-01

    The Battery Orbital Replacement Unit (ORU) was designed to meet the following requirements: a 6.5-year design life, 38,000 charge/discharge Low Earth Orbit cycles, 81-Amp-hr nameplate capacity, 4 kWh nominal storage capacity, contingency orbit capability, an operating temperature of 5 +/- 5 C standard orbit and 5+5/-10 C contingency orbit, a non-operating temperature of -25 to +30 C, a five-year Mean Time between failure, an on-orbit replacement using ISS robotic interface, and one launch to orbit and one return to ground. The ISS electrical power system is successfully maintaining power for all on-board loads. ISS Eclipse power is currently supplied by six Ni-H2 batteries (12 ORUs), which are operating nominally.

  16. Electrochemical performances of lithium ion battery using alkoxides of group 13 as electrolyte solvent

    International Nuclear Information System (INIS)

    Kaneko, Fuminari; Masuda, Yuki; Nakayama, Masanobu; Wakihara, Masataka

    2007-01-01

    Tris(methoxy polyethylenglycol) borate ester (B-PEG) and aluminum tris(polyethylenglycoxide) (Al-PEG) were used as electrolyte solvent for lithium ion battery, and the electrochemical property of these electrolytes were investigated. These electrolytes, especially B-PEG, showed poor electrochemical stability, leading to insufficient discharge capacity and rapid degradation with cycling. These observations would be ascribed to the decomposition of electrolyte, causing formation of unstable passive layer on the surface of electrode in lithium ion battery at high voltage. However, significant improvement was observed by the addition of aluminum phosphate (AlPO 4 ) powder into electrolyte solvent. AC impedance technique revealed that the increase of interfacial resistance of electrode/electrolyte during cycling was suppressed by adding AlPO 4 , and this suppression could enhance the cell capabilities. We infer that dissolved AlPO 4 components formed electrochemically stable layer on the surface of electrode

  17. Effect of sulfolane on the performance of lithium bis(oxalato)borate-based electrolytes for advanced lithium ion batteries

    International Nuclear Information System (INIS)

    Li Shiyou; Zhao Yangyu; Shi Xinming; Li Bucheng; Xu Xiaoli; Zhao Wei; Cui Xiaoling

    2012-01-01

    Highlights: ► High purity of LiBOB is obtained by the compressing dry granulation method. ► LiBOB-SL/DEC electrolyte is an excellent candidate electrolyte for lithium ion batteries. ► It shows high oxidation potentials (>5.3 V) and satisfactory conductivities. ► In Li/MCMB cells, this novel electrolyte exhibits excellent film-forming characteristics and low impedances of the interface films. ► In LiFePO 4 /Li cells, this novel electrolyte exhibits stable cycle performance and high discharge voltage plateau (>3.35 V). - Abstract: Lithium bis(oxalato)borate (LiBOB) is a promising salt for lithium ion batteries. However, before applying in lithium ion batteries, it is necessary to prepare high purity LiBOB with a simple method, and find more appropriate solvent systems to exert the perfect electrochemical performance of LiBOB. In this paper, LiBOB is synthesized by the compressing dry granulation method, with the yield of 97%. Moreover, the electrochemical performances of LiBOB-sulfolane (SL)/diethyl carbonate (DEC) electrolyte are investigated. It shows high oxidation potentials (>5.3 V) and satisfactory conductivities, also the temperature dependence of the conductivity is well in accord with the Vogel–Tamman–Fulcher (VTF) behavior. When used in Li/MCMB (mesophase carbon microbeads) cells, this novel electrolyte exhibits not only excellent film-forming characteristics, but also low impedances of the interface films. When used in LiFePO 4 /Li cells, compared to the cell with the electrolyte system of LiBOB-EC/DEC electrolyte, LiBOB-SL/DEC electrolyte exhibit several advantages, such as more stable cycle performance, and higher discharge voltage plateau (>3.35 V).

  18. Fabrication of hierarchical structured SiO2/polyetherimide-polyurethane nanofibrous separators with high performance for lithium ion batteries

    International Nuclear Information System (INIS)

    Zhai, Yunyun; Xiao, Ke; Yu, Jianyong; Ding, Bin

    2015-01-01

    Highlights: • Electrospinning followed by dip-coating was used to fabricate SiO 2 /PEI-PU membranes. • Introducing PEI, PU and SiO 2 improved safety, tensile strength and ionic conductivity. • Coating SiO 2 also restrained the micro-shorting and migrated the self-discharge. • SiO 2 /PEI-PU membranes based cell exhibited prominent cycling and rate performance. - ABSTRACT: The performance of lithium ion battery based on electrospun nanofibrous membranes has gained a great deal of attention in the past decades, but the intrinsic low mechanical strength and large pore size of electrospun membranes limit their battery performance. To overcome this limitation, a powerful strategy for designing, fabricating and evaluating silica nanoparticles coated polyetherimide-polyurethane (SiO 2 /PEI-PU) nanofibrous composite membranes is easily developed via electrospinning followed by a dip-coating process. Benefiting from the high porosity, interpenetrating network structure and synergetic effect of PU, PEI and SiO 2 nanoparticles, the as-prepared composite membranes exhibit high ionic conductivity (2.33 mS cm −1 ), robust tensile strength (15.65 MPa) and improved safety (excellent thermal resistance and flame retardant property). Additionally, the as-prepared composite membranes possess relatively narrow pore size distribution with average pore size of 0.58 μm after coating SiO 2 nanoparticles, which plays an important role in hindering the micro-shorting and mitigating self-discharge. Significantly, the SiO 2 /PEI-PU membranes based Li/LiFePO 4 cell exhibits more excellent cycling stability with capacity retention of 98.7% after 50 cycles at 0.2 C rate and better rate capability compared with the Celgard membrane based cell. The results clearly demonstrate that this is a promising separator candidate for next-generation lithium ion batteries, which may represent a significant step toward separators with improved performance

  19. Cost and performance prospects for composite bipolar plates in fuel cells and redox flow batteries

    Science.gov (United States)

    Minke, Christine; Hickmann, Thorsten; dos Santos, Antonio R.; Kunz, Ulrich; Turek, Thomas

    2016-02-01

    Carbon-polymer-composite bipolar plates (BPP) are suitable for fuel cell and flow battery applications. The advantages of both components are combined in a product with high electrical conductivity and good processability in convenient polymer forming processes. In a comprehensive techno-economic analysis of materials and production processes cost factors are quantified. For the first time a technical cost model for BPP is set up with tight integration of material characterization measurements.

  20. High-Performance Ga2O3 Anode for Lithium-Ion Batteries.

    Science.gov (United States)

    Tang, Xun; Huang, Xin; Huang, Yongmin; Gou, Yong; Pastore, James; Yang, Yao; Xiong, Yin; Qian, Jiangfeng; Brock, Joel D; Lu, Juntao; Xiao, Li; Abruña, Héctor D; Zhuang, Lin

    2018-02-14

    There is a great deal of interest in developing battery systems that can exhibit self-healing behavior, thus enhancing cyclability and stability. Given that gallium (Ga) is a metal that melts near room temperature, we wanted to test if it could be employed as a self-healing anode material for lithium-ion batteries (LIBs). However, Ga nanoparticles (NPs), when directly applied, tended to aggregate upon charge/discharge cycling. To address this issue, we employed carbon-coated Ga 2 O 3 NPs as an alternative. By controlling the pH of the precursor solution, highly dispersed and ultrafine Ga 2 O 3 NPs, embedded in carbon shells, could be synthesized through a hydrothermal carbonization method. The particle size of the Ga 2 O 3 NPs was 2.6 nm, with an extremely narrow size distribution, as determined by high-resolution transmission electron microscopy and Brunauer-Emmett-Teller measurements. A lithium-ion battery anode based on this material exhibited stable charging and discharging, with a capacity of 721 mAh/g after 200 cycles. The high cyclability is due to not only the protective effects of the carbon shell but also the formation of Ga 0 during the lithiation process, as indicated by operando X-ray absorption near-edge spectroscopy.

  1. Theoretical performance of serrated external occulters for solar coronagraphy. Application to ASPIICS

    Science.gov (United States)

    Rougeot, R.; Aime, C.

    2018-04-01

    Context. This study is made in the context of the future solar coronagraph ASPIICS of the ESA formation-flying mission Proba-3. Aims: In the context of solar coronagraphy, we provide a comparative study of the theoretical performance of serrated (or toothed) external occulters by varying the number and size of the teeth, which we compare to the sharp-edged and apodized disks. The tooth height is small (a few centimeters), to avoid hindering the observation of the solar corona near the limb. We first analyze the diffraction pattern produced by such occulters. In a second step, we compute the umbra profile by integration over the Sun. Methods: We explored a few methods to compute the diffraction pattern. Two of them were implemented. The first is based on 2D fast Fourier transformation (FFT) routines and a multiplication by the Fresnel filter of the form exp(-iπλzu2). Simple rules were derived and discussed to set the sampling conditions. The Maggi-Rubinowicz representation is then proposed as an alternative method, and is proven to be very efficient for this study. Results: Serrated occulters tend to create a two-level intensity pattern, the inner being the darker, which perfectly matches a previously reported geometrical prediction. The diffraction in this central region is lower by two to four orders of magnitude when compared to the sharp-edged disk. The achieved umbra level at the center ranges from 10-4 to below 10-7, depending on the geometry of the teeth. Conclusions: Our study shows that serrated occulters can achieve a high rejection and can almost reach the performance of the apodized disk when very many teeth are used. We prove that shaped occulters must be preferred to simple disks in solar and stellar coronagraphy.

  2. Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

    Energy Technology Data Exchange (ETDEWEB)

    Broussely, M.; Planchat, J.P.; Rigobert, G.; Virey, D.; Sarre, G. [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

    1996-12-31

    The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

  3. Performances of a lithium-carbon ``lithium ion``battery for electric powered vehicle; Performances d`un accumulateur au lithium-carbone ``Lithium Ion`` pour vehicule electrique

    Energy Technology Data Exchange (ETDEWEB)

    Broussely, M; Planchat, J P; Rigobert, G; Virey, D; Sarre, G [SAFT, Advanced and Industrial Battery Group, 86 - Poitiers (France)

    1997-12-31

    The lithium battery, also called `lithium-carbon` or `lithium ion`, is today the most promising candidate that can reach the expected minimum traction performances of electric powered vehicles. Thanks to a more than 20 years experience on lithium generators and to a specific research program on lithium batteries, the SAFT company has developed a 100 Ah electrochemical system, and full-scale prototypes have been manufactured for this application. These prototypes use the Li{sub x}NiO{sub 2} lithiated graphite electrochemical pair and were tested in terms of their electrical performances. Energy characteristics of 125 Wh/kg and 265 Wh/dm{sup 3} could be obtained. The possibility of supplying a power greater than 200 W/kg, even at low temperature (-10 deg. C) has been demonstrated with these elements. A full battery set of about 20 kWh was built and its evaluation is in progress. It comprises the electronic control systems for the optimum power management during charge and output. (J.S.) 9 refs.

  4. Modification of SnO2 Anodes by Atomic Layer Deposition for High Performance Lithium Ion Batteries

    KAUST Repository

    Yesibolati, Nulati

    2013-05-01

    Tin dioxide (SnO2) is considered one of the most promising anode materials for Lithium ion batteries (LIBs), due to its large theoretical capacity and natural abundance. However, its low electronic/ionic conductivities, large volume change during lithiation/delithiation and agglomeration prevent it from further commercial applications. In this thesis, we investigate modified SnO2 as a high energy density anode material for LIBs. Specifically two approaches are presented to improve battery performances. Firstly, SnO2 electrochemical performances were improved by surface modification using Atomic Layer Deposition (ALD). Ultrathin Al2O3 or HfO2 were coated on SnO2 electrodes. It was found that electrochemical performances had been enhanced after ALD deposition. In a second approach, we implemented a layer-by-layer (LBL) assembled graphene/carbon-coated hollow SnO2 spheres as anode material for LIBs. Our results indicated that the LBL assembled electrodes had high reversible lithium storage capacities even at high current densities. These superior electrochemical performances are attributed to the enhanced electronic conductivity and effective lithium diffusion, because of the interconnected graphene/carbon networks among nanoparticles of the hollow SnO2 spheres.

  5. Performance and organ morphology of broilers fed microbial or antimicrobial additives and raised in batteries or floor pens

    Directory of Open Access Journals (Sweden)

    Pedroso AA

    2003-01-01

    Full Text Available This study was conducted to determine the effect of microbial or antimicrobial additives on the performance and organ morphology of broilers raised in batteries or in floor pens. The effect of microbial additives on the presence of oocysts in the litter was also studied. Experiments 1 and 2 consisted of four treatments (non-supplemented control diet or diet supplemented with avilamycin, bacitracin methylene disalicylate or enramycin and six repetitions in a randomized block design. In Experiment 1, 288 day-old chicks were housed in heated batteries in a environmentally controlled room, 12 chicks per cage; in Experiment 2, 1,200 day-old chicks were housed in a curtain-sided experimental house, with concrete floor and rice hulls as litter material, 50 chicks per pen. Experiments 3 and 4 were carried out similarly to Experiments 1 and 2, respectively, but the treatments consisted of microbial additives (non-supplemented control diet or Bacillus subtilis added to the feed plus Lactobacillus reuteri and Lactobacillus johnsonii added to the water, undefined microflora added to the water or live yeast added to the feed. The antibiotics did not affect the performance of birds raised in batteries, but improved feed conversion, weight gain and live weight when chickens were kept on the floor pens. Microbial additives did not affect bird performance in any environment; however, treatments affected liver weight. Microbial agents increased intestinal weight in floor-raised broilers. No relationship was seen between the use of microbial additives and the presence of oocysts in the litter.

  6. Mesoporous nickel oxide nanowires: hydrothermal synthesis, characterisation and applications for lithium-ion batteries and supercapacitors with superior performance.

    Science.gov (United States)

    Su, Dawei; Kim, Hyun-Soo; Kim, Woo-Seong; Wang, Guoxiu

    2012-06-25

    Mesoporous nickel oxide nanowires were synthesized by a hydrothermal reaction and subsequent annealing at 400 °C. The porous one-dimensional nanostructures were analysed by field-emission SEM, high-resolution TEM and N(2) adsorption/desorption isotherm measurements. When applied as the anode material in lithium-ion batteries, the as-prepared mesoporous nickel oxide nanowires demonstrated outstanding electrochemical performance with high lithium storage capacity, satisfactory cyclability and an excellent rate capacity. They also exhibited a high specific capacitance of 348 F g(-1) as electrodes in supercapacitors. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Micro-sized organometallic compound of ferrocene as high-performance anode material for advanced lithium-ion batteries

    Science.gov (United States)

    Liu, Zhen; Feng, Li; Su, Xiaoru; Qin, Chenyang; Zhao, Kun; Hu, Fang; Zhou, Mingjiong; Xia, Yongyao

    2018-01-01

    An organometallic compound of ferrocene is first investigated as a promising anode for lithium-ion batteries. The electrochemical properties of ferrocene are conducted by galvanostatic charge and discharge. The ferrocene anode exhibits a high reversible capacity and great cycling stability, as well as superior rate capability. The electrochemical reaction of ferrocene is semi-reversible and some metallic Fe remains in the electrode even after delithiation. The metallic Fe formed in electrode and the stable solid electrolyte interphase should be responsible for its excellent electrochemical performance.

  8. Highly conductive bridges between graphite spheres to improve the cycle performance of a graphite anode in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongyu [IM and T Ltd., Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan); Umeno, Tatsuo; Mizuma, Koutarou [Research Center, Mitsui Mining Co. Ltd., Hibiki-machi 1-3, Wakamatsu-ku, Kitakyushu 808-0021 (Japan); Yoshio, Masaki [Advanced Research Center, Saga University, Yoga-machi 1341, Saga 840-0047 (Japan)

    2008-01-10

    Spherical carbon-coated natural graphite (SCCNG) is a promising anode material for lithium-ion batteries, but the smooth surface of graphite spheres is difficult to wet with an aqueous binder solution, and lacks electrical contacts. As a result, the cycle performance of such a graphite anode material is not satisfactory. An effective method has been introduced to tightly connect adjacent SCCNG particles by a highly conductive binder, viz. acetylene black bridges. The effect of the conductive bridges on the cyclability of SCCNG electrode has been investigated. (author)

  9. The physicochemical properties of a [DEME][TFSI] ionic liquid-based electrolyte and their influence on the performance of lithium–sulfur batteries

    International Nuclear Information System (INIS)

    Drvarič Talian, Sara; Bešter-Rogač, Marija; Dominko, Robert

    2017-01-01

    Electrolyte choice is an important decision on the quest for higher-energy batteries. Besides general guidelines on the required properties of an electrolyte suitable for use in lithium–sulfur batteries, the influence of more specific physicochemical properties on its characteristics is not well understood. For this purpose, binary mixtures based on the [DEME][TFSI] and dioxolane electrolyte system for lithium–sulfur batteries was investigated in this work. Selected physicochemical properties were determined for different mixtures of solvents and lithium salt concentrations. All the electrolytes prepared were also tested in the lithium–sulfur battery system. The capacity, Coulombic efficiency, overpotentials and impedance spectra were analyzed and a connection between them and the determined electrolyte properties elucidated. We show that the electrolyte's conductivity does not have a direct connection to any of the battery system properties measured. The highest specific capacities were obtained with batteries compromising 1.0 M LiTFSI and the highest ratio of dioxolane in the binary solvent mixture. On the other hand, the best Coulombic efficiencies were obtained with batteries having high ratios of ionic liquid. Resistance and overpotential are connected parameters and are a function of the ionic liquid content. None of the monitored parameters prevail, since the best electrochemical performance in terms of specific capacity and stability was obtained with the 1.0 M LiTFSI in X[DEME][TFSI] = 0.199 electrolyte.

  10. Hip external rotation strength predicts hop performance after anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Kline, Paul W; Burnham, Jeremy; Yonz, Michael; Johnson, Darren; Ireland, Mary Lloyd; Noehren, Brian

    2018-04-01

    Quadriceps strength and single-leg hop performance are commonly evaluated prior to return to sport after anterior cruciate ligament reconstruction (ACLR). However, few studies have documented potential hip strength deficits after ACLR, or ascertained the relative contribution of quadriceps and hip strength to hop performance. Patients cleared for return to sports drills after ACLR were compared to a control group. Participants' peak isometric knee extension, hip abduction, hip extension, and hip external rotation (HER) strength were measured. Participants also performed single-leg hops, timed hops, triple hops, and crossover hops. Between-limb comparisons for the ACLR to control limb and the non-operative limb were made using independent two-sample and paired sample t tests. Pearson's correlations and stepwise multiple linear regression were used to determine the relationships and predictive ability of limb strength, graft type, sex, and limb dominance to hop performance. Sixty-five subjects, 20 ACLR [11F, age 22.8 (15-45) years, 8.3 ± 2 months post-op, mass 70.47 ± 12.95 kg, height 1.71 ± 0.08 m, Tegner 5.5 (3-9)] and 45 controls [22F, age 25.8 (15-45) years, mass 74.0 ± 15.2 kg, height 1.74 ± 0.1 m, Tegner 6 (3-7)], were tested. Knee extension (4.4 ± 1.5 vs 5.4 ± 1.8 N/kg, p = 0.02), HER (1.4 ± 0.4 vs 1.7 ± 0.5 N/kg, p = 0.04), single-leg hop (146 ± 37 vs 182 ± 38% limb length, p hop (417 ± 106 vs 519 ± 102% limb length, p hop (3.3 ± 2.0 vs 2.3 ± 0.6 s, p hop (364 ± 107 vs 446 ± 123% limb length, p = 0.01) were significantly impaired in the operative versus control subject limbs. Similar deficits existed between the operative and non-operative limbs. Knee extension and HER strength were significantly correlated with each of the hop tests, but only HER significantly predicted hop performance. After ACLR, patients have persistent HER strength, knee extension strength, and hop test deficits in the

  11. A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

    KAUST Repository

    Zhao, Huaying

    2015-05-21

    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

  12. A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

    Directory of Open Access Journals (Sweden)

    Huaying Zhao

    Full Text Available Analytical ultracentrifugation (AUC is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188 S (4.4%. After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%. In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

  13. A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

    KAUST Repository

    Zhao, Huaying; Ghirlando, Rodolfo; Alfonso, Carlos; Arisaka, Fumio; Attali, Ilan; Bain, David L.; Bakhtina, Marina M.; Becker, Donald F.; Bedwell, Gregory J.; Bekdemir, Ahmet; Besong, Tabot M.D.; Birck, Catherine; Brautigam, Chad A.; Brennerman, William; Byron, Olwyn; Bzowska, Agnieszka; Chaires, Jonathan B.; Chaton, Catherine T.; Cö lfen, Helmut; Connaghan, Keith D.; Crowley, Kimberly A.; Curth, Ute; Daviter, Tina; Dean, William L.; Dí ez, Ana I.; Ebel, Christine; Eckert, Debra M.; Eisele, Leslie E.; Eisenstein, Edward; England, Patrick; Escalante, Carlos; Fagan, Jeffrey A.; Fairman, Robert; Finn, Ron M.; Fischle, Wolfgang; de la Torre, José Garcí a; Gor, Jayesh; Gustafsson, Henning; Hall, Damien; Harding, Stephen E.; Cifre, José G. Herná ndez; Herr, Andrew B.; Howell, Elizabeth E.; Isaac, Richard S.; Jao, Shu-Chuan; Jose, Davis; Kim, Soon-Jong; Kokona, Bashkim; Kornblatt, Jack A.; Kosek, Dalibor; Krayukhina, Elena; Krzizike, Daniel; Kusznir, Eric A.; Kwon, Hyewon; Larson, Adam; Laue, Thomas M.; Le Roy, Aline; Leech, Andrew P.; Lilie, Hauke; Luger, Karolin; Luque-Ortega, Juan R.; Ma, Jia; May, Carrie A.; Maynard, Ernest L.; Modrak-Wojcik, Anna; Mok, Yee-Foong; Mü cke, Norbert; Nagel-Steger, Luitgard; Narlikar, Geeta J.; Noda, Masanori; Piszczek, Grzegorz; Nourse, Amanda; Obsil, Tomas; Park, Chad K.; Park, Jin-Ku; Pawelek, Peter D.; Perdue, Erby E.; Perkins, Stephen J.; Perugini, Matthew A.; Peterson, Craig L.; Peverelli, Martin G.; Prag, Gali; Prevelige, Peter E.; Raynal, Bertrand D. E.; Rezabkova, Lenka; Richter, Klaus; Ringel, Alison E.; Rosenberg, Rose; Rowe, Arthur J.; Rufer, Arne C.; Swygert, Sarah G.; Scott, David J.; Seravalli, Javier G.; Solovyova, Alexandra S.; Song, Renjie; Staunton, David; Stoddard, Caitlin; Stott, Katherine; Strauss, Holger M.; Streicher, Werner W.; Sumida, John P.; Szczepanowski, Roman H.; Tessmer, Ingrid; Toth, Ronald T.; Tripathy, Ashutosh; Uchiyama, Susumu; Uebel, Stephan F. W.; Unzai, Satoru; Gruber, Anna Vitlin; von Hippel, Peter H.; null; Wandrey, Christine; Wang, Szu-Huan; Weitzel, Steven E.; Wielgus-Kutrowska, Beata; Wolberger, Cynthia; Wolff, Martin; Wright, Edward; Wu, Yu-Sung; Wubben, Jacinta M.; Schuck, Peter

    2015-01-01

    Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

  14. V2O5-C-SnO2 Hybrid Nanobelts as High Performance Anodes for Lithium-ion Batteries

    Science.gov (United States)

    Zhang, Linfei; Yang, Mingyang; Zhang, Shengliang; Wu, Zefei; Amini, Abbas; Zhang, Yi; Wang, Dongyong; Bao, Shuhan; Lu, Zhouguang; Wang, Ning; Cheng, Chun

    2016-09-01

    The superior performance of metal oxide nanocomposites has introduced them as excellent candidates for emerging energy sources, and attracted significant attention in recent years. The drawback of these materials is their inherent structural pulverization which adversely impacts their performance and makes the rational design of stable nanocomposites a great challenge. In this work, functional V2O5-C-SnO2 hybrid nanobelts (VCSNs) with a stable structure are introduced where the ultradispersed SnO2 nanocrystals are tightly linked with glucose on the V2O5 surface. The nanostructured V2O5 acts as a supporting matrix as well as an active electrode component. Compared with existing carbon-V2O5 hybrid nanobelts, these hybrid nanobelts exhibit a much higher reversible capacity and architectural stability when used as anode materials for lithium-ion batteries. The superior cyclic performance of VCSNs can be attributed to the synergistic effects of SnO2 and V2O5. However, limited data are available for V2O5-based anodes in lithium-ion battery design.

  15. N/S Co-doped Carbon Derived From Cotton as High Performance Anode Materials for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Jiawen Xiong

    2018-04-01

    Full Text Available Highly porous carbon with large surface areas is prepared using cotton as carbon sources which derived from discard cotton balls. Subsequently, the sulfur-nitrogen co-doped carbon was obtained by heat treatment the carbon in presence of thiourea and evaluated as Lithium-ion batteries anode. Benefiting from the S, N co-doping, the obtained S, N co-doped carbon exhibits excellent electrochemical performance. As a result, the as-prepared S, N co-doped carbon can deliver a high reversible capacity of 1,101.1 mA h g−1 after 150 cycles at 0.2 A g−1, and a high capacity of 531.2 mA h g−1 can be observed even after 5,000 cycles at 10.0 A g−1. Moreover, excellently rate capability also can be observed, a high capacity of 689 mA h g−1 can be obtained at 5.0 A g−1. This superior lithium storage performance of S, N co-doped carbon make it as a promising low-cost and sustainable anode for high performance lithium ion batteries.

  16. The effect of hydrogenation on the growth of carbon nanospheres and their performance as anode materials for rechargeable lithium-ion batteries

    Science.gov (United States)

    Zhao, Shijia; Fan, Yunxia; Zhu, Kai; Zhang, Dong; Zhang, Weiwei; Chen, Shuanglong; Liu, Ran; Yao, Mingguang; Liu, Bingbing

    2015-01-01

    Hydrogenated carbon nanomaterials exhibit many advantages in both mechanical and electrochemical properties, and thus have a wide range of potential applications. However, methods to control the hydrogenation and the effect of hydrogenation on the microstructure and properties of the produced nanomaterials have rarely been studied. Here we report the synthesis of hydrogenated carbon nanospheres (HCNSs) with different degrees of hydrogenation by a facile solvothermal method, in which C2H3Cl3/C2H4Cl2 was used as the carbon precursor and potassium as the reductant. The hydrogenation level of the obtained nanospheres depends on the reaction temperature and higher temperature leads to lower hydrogenation due to the fact that the breaking of C-H bonds requires more external energy. The reaction temperature also affects the diameter of the HCNSs and larger spheres are produced at higher temperatures. More importantly, the size and the degree of hydrogenation are both critical factors for determining the electrochemical properties of the HCNSs. The nanospheres synthesized at 100 °C have a smaller size and a higher hydrogenation degree and show a capacity of 821 mA h g-1 after 50 cycles, which is significantly higher than that of the HCNSs produced at 150 °C (450 mA h g-1). Our study opens a possible way for obtaining high-performance anode materials for rechargeable lithium-ion batteries.

  17. Batteries: Overview of Battery Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Doeff, Marca M

    2010-07-12

    The very high theoretical capacity of lithium (3829 mAh/g) provided a compelling rationale from the 1970's onward for development of rechargeable batteries employing the elemental metal as an anode. The realization that some transition metal compounds undergo reductive lithium intercalation reactions reversibly allowed use of these materials as cathodes in these devices, most notably, TiS{sub 2}. Another intercalation compound, LiCoO{sub 2}, was described shortly thereafter but, because it was produced in the discharged state, was not considered to be of interest by battery companies at the time. Due to difficulties with the rechargeability of lithium and related safety concerns, however, alternative anodes were sought. The graphite intercalation compound (GIC) LiC{sub 6} was considered an attractive candidate but the high reactivity with commonly used electrolytic solutions containing organic solvents was recognized as a significant impediment to its use. The development of electrolytes that allowed the formation of a solid electrolyte interface (SEI) on surfaces of the carbon particles was a breakthrough that enabled commercialization of Li-ion batteries. In 1990, Sony announced the first commercial batteries based on a dual Li ion intercalation system. These devices are assembled in the discharged state, so that it is convenient to employ a prelithiated cathode such as LiCoO{sub 2} with the commonly used graphite anode. After charging, the batteries are ready to power devices. The practical realization of high energy density Li-ion batteries revolutionized the portable electronics industry, as evidenced by the widespread market penetration of mobile phones, laptop computers, digital music players, and other lightweight devices since the early 1990s. In 2009, worldwide sales of Li-ion batteries for these applications alone were US$ 7 billion. Furthermore, their performance characteristics (Figure 1) make them attractive for traction applications such as

  18. Ramping Performance Analysis of the Kahuku Wind-Energy Battery Storage System

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, V. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Corbus, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-11-01

    High penetrations of wind power on the electrical grid can introduce technical challenges caused by resource variability. Such variability can have undesirable effects on the frequency, voltage, and transient stability of the grid. Energy storage devices can be an effective tool in reducing variability impacts on the power grid in the form of power smoothing and ramp control. Integrating anenergy storage system with a wind power plant can help smooth the variable power produced from wind. This paper explores the fast-response, megawatt-scale, wind-energy battery storage systems that were recently deployed throughout the Hawaiian islands to support wind and solar projects.

  19. A dynamic performance model for redox-flow batteries involving soluble species

    International Nuclear Information System (INIS)

    Shah, A.A.; Watt-Smith, M.J.; Walsh, F.C.

    2008-01-01

    A transient modelling framework for a vanadium redox-flow battery (RFB) is developed and experiments covering a range of vanadium concentration and electrolyte flow rate are conducted. The two-dimensional model is based on a comprehensive description of mass, charge and momentum transport and conservation, and is combined with a global kinetic model for reactions involving vanadium species. The model is validated against the experimental data and is used to study the effects of variations in concentration, electrolyte flow rate and electrode porosity. Extensions to the model and future work are suggested

  20. The internal and external customer focused process improvement and the performance analysis studies in healthcare systems

    Directory of Open Access Journals (Sweden)

    Piril Tekin

    2017-07-01

    Full Text Available Purpose: The main contribution of this paper is to generate an optimum solution for capacity planning and appointment scheduling issues, which are frequently encountered in clinical flows with various route and treatment periods at dental hospitals. Design/methodology/approach: It is essential to define the system well in order to ensure that the working staff and patients use their time very efficiently and that the process flows continuously. By having examined a sample healthcare system through the help of a study addressed in such context, studies on process improvement in line with the dissatisfactions of the working staff and patients have been carried out. Within the scope of the study, the operation of 7 Departments in a dental hospital undergoing a treatment process have been reviewed and examined. The problems encountered as result of the observations made are discussed in detail, and formerly and recently designed system performance analyses are conducted by having performed the respective process improvement studies. The relevant samplings of this study are modeled via the Arena Simulation Program. The data of the previous four months is used in the parameters, which are used through the modellings. The system data are entered by taking into account seasonal characteristics of the data. Findings: The analyses are made as a consequence of such study that has been addressed, it is established that the efficiency of the internal customers of the hospital increases substantially, and that the waiting durations of the dental patients decrease and in turn, the external customer satisfaction increases drastically. Research limitations/implications: Under the scope of the present study, 7 different treatment processes are analysed in a dental hospital in Cukurova Region with a significant patient potential. The treatment clinics present in the hospital are radiology, periodontology, surgery, treatment, orthodontics and prosthesis. These

  1. Performance Degradation of Thermal Parameters during Cycle Ageing of High Energy Density Ni-Mn-Co based Lithium-Ion Battery Cells

    DEFF Research Database (Denmark)

    Stanciu, Tiberiu; Stroe, Daniel Loan; Swierczynski, Maciej Jozef

    2016-01-01

    The accelerated demand for electrifying the transportation sector, coupled with the continuous improvement of rechargeable batteries’ characteristics, have made modern high-energy Lithium-ion (Li-ion) batteries the standard choice for hybrid and electric vehicles (EVs). Consequently, Li......-ion batteries’ electrochemical and thermal characteristics are very important topics, putting them at the forefront of the research. Along with the electrical performance of Li-ion battery cells, their thermal behavior needs to be accurately predicted during operation and over the lifespan of the application...... as well, since the thermal management of the battery is crucial for the safety of the EV driver. Moreover, the thermal management system can significantly lower the degradation rate of the battery pack and thus reduce costs. In this paper, the thermal characterization of a commercially available Nickel...

  2. Redox flow batteries with serpentine flow fields: Distributions of electrolyte flow reactant penetration into the porous carbon electrodes and effects on performance

    Science.gov (United States)

    Ke, Xinyou; Prahl, Joseph M.; Alexander, J. Iwan D.; Savinell, Robert F.

    2018-04-01

    Redox flow batteries with flow field designs have been demonstrated to boost their capacities to deliver high current density and power density in medium and large-scale energy storage applications. Nevertheless, the fundamental mechanisms involved with improved current density in flow batteries with serpentine flow field designs have been not fully understood. Here we report a three-dimensional model of a serpentine flow field over a porous carbon electrode to examine the distributions of pressure driven electrolyte flow penetrations into the porous carbon electrodes. We also estimate the maximum current densities associated with stoichiometric availability of electrolyte reactant flow penetrations through the porous carbon electrodes. The results predict reasonably well observed experimental data without using any adjustable parameters. This fundamental work on electrolyte flow distributions of limiting reactant availability will contribute to a better understanding of limits on electrochemical performance in flow batteries with serpentine flow field designs and should be helpful to optimizing flow batteries.

  3. The Importance of External Contacts in Job Performance: A Study in Healthcare Organizations Using Social Network Analysis

    Directory of Open Access Journals (Sweden)

    Pilar Marqués-Sánchez

    2018-06-01

    Full Text Available There is evidence that relations between physicians and nurses within healthcare institutions might be shaped by informal aspects of such relations and by links to people external to the organization, with an impact on work performance. Social network analysis is underutilized in exploring such associations. The paper aims to describe physicians’ and nurses’ relationships outside their clinical units and to explore what kind of ties are related to job performance. A network analysis was performed on cross-sectional data. The study population consisted of 196 healthcare employees working in a public hospital and a primary healthcare centre in Spain. Relational data were analysed using the UCINET software package. Measures included: (i sample characteristics; (ii social network variables; and (iii team performance ratings. Descriptive statistics (means, medians, percentages were used to characterize staff and performance ratings. A correlational analysis was conducted to examine the strength of relationships between four different types of ties. Our findings suggest that external ties only contribute to improving the performance of physicians at both the individual and team level. They are focused on the decision-making process about the therapeutic plan and, therefore, might need to seek advice outside the workplace. In contrast, external ties are not relevant for the work performance of nurses, as they need to find solutions to immediate problems in a short period of time, having strong ties in the workplace. Social network analysis can illuminate relations within healthcare organizations and inform the development of innovative interventions.

  4. Bismuth nanoparticle decorating graphite felt as a high-performance electrode for an all-vanadium redox flow battery.

    Science.gov (United States)

    Li, Bin; Gu, Meng; Nie, Zimin; Shao, Yuyan; Luo, Qingtao; Wei, Xiaoliang; Li, Xiaolin; Xiao, Jie; Wang, Chongmin; Sprenkle, Vincent; Wang, Wei

    2013-03-13

    Employing electrolytes containing Bi(3+), bismuth nanoparticles are synchronously electrodeposited onto the surface of a graphite felt electrode during operation of an all-vanadium redox flow battery (VRFB). The influence of the Bi nanoparticles on the electrochemical performance of the VRFB is thoroughly investigated. It is confirmed that Bi is only present at the negative electrode and facilitates the redox reaction between V(II) and V(III). However, the Bi nanoparticles significantly improve the electrochemical performance of VRFB cells by enhancing the kinetics of the sluggish V(II)/V(III) redox reaction, especially under high power operation. The energy efficiency is increased by 11% at high current density (150 mA·cm(-2)) owing to faster charge transfer as compared with one without Bi. The results suggest that using Bi nanoparticles in place of noble metals offers great promise as high-performance electrodes for VRFB application.

  5. Carbon coated CoS_2 thermal battery electrode material with enhanced discharge performances and air stability

    International Nuclear Information System (INIS)

    Xie, Song; Deng, Yafeng; Mei, Jun; Yang, Zhaotang; Lau, Woon-Ming; Liu, Hao

    2017-01-01

    Graphical abstract: A novel carbon coated CoS_2 composite is prepared and investigated as a cathode material for thermal batteries. - Highlights: • A novel C@CoS_2 composite is successfully prepared by hydrothermal method. • The growth of CoS_2 in the glucose solution results in a smaller grain size. • The coating of carbon favors electron transfer and buffers polysulfides formation. • The in situ coated carbon layer effectively prevents the oxidation of CoS_2. • The C@CoS_2 composite shows competitive thermal stability and discharge property. - Abstract: Cobalt disulfide (CoS_2) is a promising thermal battery electrode material for its superior thermal stability and discharge performance. However, the low natural resource and poor air stability restrict its application in thermal battery fabrication. In this work, carbon coated CoS_2 composite was prepared by a facile one-pot hydrothermal method with glucose as carbon source. During the growth of CoS_2, the glucose molecules were in situ adsorbed and carbonized on the surface of the as-synthesized CoS_2, and the resultant carbon coating provided improved electrical conductivity and discharge performances to the composite. The thermal battery cell, which was fabricated with such a composite cathode and with a Li-Si anode, can output a capacity of 235.8 mAh g"−"1 and an energy density of 416.9 Wh kg"−"1 at a cut-off voltage of 1.7 V. This carbon coated CoS_2 composite also presented enhanced air stability. After being stored in dry air for 3 months, the composite can still provide a capacity of 232.4 mAh g"−"1 to 1.7 V, whereas the capacity of bare CoS_2 stored with the same condition dropped from 202.4 mAh g"−"1 to 189.7 mAh g"−"1.

  6. Manganese pyridinedicarboxylates: New anode materials for lithium-ion batteries with good cycling performance

    International Nuclear Information System (INIS)

    Fei, Hailong; Li, Zhiwei; Liu, Xin

    2015-01-01

    Highlights: • Manganese 2,3-pyridinedicarboxylate and 2,5-pyridinedicarboxylate. • Firstly tested as anode materials. • High capacity and good cycle stability. - Abstract: It is significant to discover new environmental friendly, sustainable and renewable electrode materials for lithium-ion batteries. Manganese dicarboxylate [Mn 2 (pdc) 2 (H 2 O) 3 ] n ⋅2nH 2 O (pdc = pyridine-2,3-dicarboxylate) is firstly found to be a high-energy anode material for lithium-ion batteries. It shows a high discharge capacity of 573.7 mA h g −1 for the second cycle between a 0.05 and 3.0 V voltage limit at a discharge current density of 500 mA g −1 . The reversible capacity of 457.2 mA h g −1 is remained after 100 cycles with a capacity retention being 79.6%. In addition, it is found that Mn 2,5-pyridinedicarboxyle was also stable anode materials with high capacity

  7. Manganese pyridinedicarboxylates: New anode materials for lithium-ion batteries with good cycling performance

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Hailong, E-mail: feilin09053@gmail.com [College of Chemistry, Fuzhou University, 2 Xueyuan Road, University Town Fuzhou, Fujian 350116 (China); Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071 (China); Li, Zhiwei; Liu, Xin [College of Chemistry, Fuzhou University, 2 Xueyuan Road, University Town Fuzhou, Fujian 350116 (China)

    2015-08-15

    Highlights: • Manganese 2,3-pyridinedicarboxylate and 2,5-pyridinedicarboxylate. • Firstly tested as anode materials. • High capacity and good cycle stability. - Abstract: It is significant to discover new environmental friendly, sustainable and renewable electrode materials for lithium-ion batteries. Manganese dicarboxylate [Mn{sub 2}(pdc){sub 2}(H{sub 2}O){sub 3}]{sub n}⋅2nH{sub 2}O (pdc = pyridine-2,3-dicarboxylate) is firstly found to be a high-energy anode material for lithium-ion batteries. It shows a high discharge capacity of 573.7 mA h g{sup −1} for the second cycle between a 0.05 and 3.0 V voltage limit at a discharge current density of 500 mA g{sup −1}. The reversible capacity of 457.2 mA h g{sup −1} is remained after 100 cycles with a capacity retention being 79.6%. In addition, it is found that Mn 2,5-pyridinedicarboxyle was also stable anode materials with high capacity.

  8. Effect of surface transport properties on the performance of carbon plastic electrodes for flow battery applications

    International Nuclear Information System (INIS)

    Sun, Xihe; Souier, Tewfik; Chiesa, Matteo; Vassallo, Anthony

    2014-01-01

    Due to their high electrical conductivity and corrosion resistance, carbon nanotube (MWNT)-high density polyethylene (HDPE) composites are potential candidates to replace traditional activated carbon electrodes for the next generation of fuel-cells, super capacitors and flow batteries. Electrochemical impedance spectroscopy (EIS) is employed to separate the surface conduction from bulk conduction in 15% HDPE-MWNT and 19% carbon black (CB)-HDPE composites for zinc-bromine flow battery electrodes. While exhibiting superior bulk conductivity, the interfacial conductivity of MWNT-filled composites is lower than that of CB-filled composites. High resolution conductive atomic force microscopy (C-AFM) imaging and current-voltage (I-V) spectroscopy were employed to investigate the sub-surface electronic transport of the composite. Unlike the CB-composite, the fraction of conducting MWNTs near the surface is very low compared to their volume fraction. In addition, the non-linear I-V curves reveal the presence of a tunneling junction between the tip and the polymer-coated MWNTs. The tunneling resistance is as high as 1 GΩ, which strongly affects the electronic/electrochemical transfer at the interface of the electrolyte and the surface of the composite, which is evident in the voltammetric and EIS observations

  9. Inorganic Glue Enabling High Performance of Silicon Particles as Lithium Ion Battery Anode

    KAUST Repository

    Cui, Li-Feng

    2011-01-01

    Silicon, as an alloy-type anode material, has recently attracted lots of attention because of its highest known Li+ storage capacity (4200 mAh/g). But lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Silicon nanostructures such as nanowires and nanotubes can overcome the pulverization problem, however these nano-engineered silicon anodes usually involve very expensive processes and have difficulty being applied in commercial lithium ion batteries. In this study, we report a novel method using amorphous silicon as inorganic glue replacing conventional polymer binder. This inorganic glue method can solve the loss of contact issue in conventional silicon particle anode and enables successful cycling of various sizes of silicon particles, both nano-particles and micron particles. With a limited capacity of 800 mAh/g, relatively large silicon micron-particles can be stably cycled over 200 cycles. The very cheap production of these silicon particle anodes makes our method promising and competitive in lithium ion battery industry. © 2011 The Electrochemical Society.

  10. Lithium storage performance of carbon nanotubes prepared from polyaniline for lithium-ion batteries

    International Nuclear Information System (INIS)

    Xiang Xiaoxia; Huang Zhengzheng; Liu Enhui; Shen Haijie; Tian Yingying; Xie Hui; Wu Yuhu; Wu Zhilian

    2011-01-01

    Highlights: → Polyaniline nanotube is synthesized by the self-assembly method in aqueous media. → Carbon nanotubes were prepared from polyaniline nanotube by physical activation. → Activation leads to large surface area, and surface nitrogen and oxygen functional groups. → Such physical and chemical properties lead to the good electrochemical properties. → After 20 cycles, a reversible capacity of 728 mAh g -1 was obtained. - Abstract: Carbon nanotubes with large surface area and surface nitrogen and oxygen functional groups are prepared by carbonizing and activating of polyaniline nanotubes, which is synthesized by polymerization of aniline with the self-assembly method in aqueous media. The physicochemical properties of the carbon nanotubes are characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller, elemental analyses and X-ray photoelectron spectroscopy measurements. The surface area and pore diameter are 618.9 m 2 g -1 and 3.10 nm. The electrochemical properties of the carbon nanotubes as anode materials in lithium ion batteries are evaluated. At a current density of 100 mA g -1 , the activated carbon nanotube shows an enormously first discharge capacity of about 1370 mAh g -1 and a charge capacity of 907 mAh g -1 . After 20 cycling tests, the activated carbon nanotube retains a reversible capacity of 728 mAh g -1 . These indicate it may be a promising candidate for an anode material for lithium secondary batteries.

  11. Synthesis and Electrochemical Performance of a Lithium Titanium Phosphate Anode for Aqueous Lithium-Ion Batteries

    KAUST Repository

    Wessells, Colin

    2011-01-01

    Lithium-ion batteries that use aqueous electrolytes offer safety and cost advantages when compared to today\\'s commercial cells that use organic electrolytes. The equilibrium reaction potential of lithium titanium phosphate is -0.5 V with respect to the standard hydrogen electrode, which makes this material attractive for use as a negative electrode in aqueous electrolytes. This material was synthesized using a Pechini type method. Galvanostatic cycling of the resulting lithium titanium phosphate showed an initial discharge capacity of 115 mAh/g and quite good capacity retention during cycling, 84% after 100 cycles, and 70% after 160 cycles at a 1 C cycling rate in an organic electrolyte. An initial discharge capacity of 113 mAh/g and capacity retention of 89% after 100 cycles with a coulombic efficiency above 98% was observed at a C/5 rate in pH -neutral 2 M Li2 S O4. The good cycle life and high efficiency in an aqueous electrolyte demonstrate that lithium titanium phosphate is an excellent candidate negative electrode material for use in aqueous lithium-ion batteries. © 2011 The Electrochemical Society.

  12. Electrochemical performance of Fe3O4 micro flower as anode for lithium ion batteries

    Science.gov (United States)

    Noerochim, Lukman; Anggara, Dika; Susanti, Diah; Subhan, Achmad; Sudaryanto

    2018-04-01

    Graphite is generally employed in commercial lithium ion batteries which has a specific capacity of 372 mAh/g. In this study, graphite is replaced with carbon-coated magnetite (Fe3O4/C) which has large theoretical specific capacity of 926 mAh/g, environmental friendly, and low cost production. The synthesis of Fe3O4/C is carried out by hydrothermal method with reacting FeCl3 and hexamethylenetetramine (HMT) at temperature variation of 160, 170 and 180°C. The following process is heated by calcination at temperature variations 450, 500 and 550°C. XRD and SEM results show that the as-prepared Fe3O4/C powder has a single phase of Fe3O4 and morphology micro-flowers like with size between 700 nm - 3 µm. CV test results show redox reaction occurs in the voltage range between 0.21-0.85 V and 1.68-1.81 V. The highest specific discharge capacity is obtained 644 mAh/g for specimen with temperature hydrothermal of 170°C and temperature calcination of 550°C. This result shows that Fe3O4/C has a high potential as anode material for lithium ion battery.

  13. Alkali Metal-O2 Batteries. Performance and Lifetime Limiting Effects

    DEFF Research Database (Denmark)

    Knudsen, Kristian Bastholm

    The rechargeable Na-O2 and Li-O2 batteries are attractive battery technologies as they potentially are very cheap and as they theoretically possess about 3 and 10 times higher energy density than the current Li-ion technologies. This PhD thesis is dedicated to studying the effects that limit cell...... product, Li2O2, was investigated. This was done by using of a conventional three electrode cell in which the heterogeneous electron transfer rate of three different redox couples were studied on Li2O2 coated glassy carbon electrodes to provide a measure of the conductivity of the Li2O2 layers. Charge....... The capacitance of the cathode was shown to be sensitive to the thickness of the deposited Li2O2 layer. These investigations also explored the influence of the composition of the electrolyte and conditions, which favors a solution mediated Li2O2 deposition mechanism. On charge, an electrochemical “safe” operating...

  14. Strain measurement based battery testing

    Science.gov (United States)

    Xu, Jeff Qiang; Steiber, Joe; Wall, Craig M.; Smith, Robert; Ng, Cheuk

    2017-05-23

    A method and system for strain-based estimation of the state of health of a battery, from an initial state to an aged state, is provided. A strain gauge is applied to the battery. A first strain measurement is performed on the battery, using the strain gauge, at a selected charge capacity of the battery and at the initial state of the battery. A second strain measurement is performed on the battery, using the strain gauge, at the selected charge capacity of the battery and at the aged state of the battery. The capacity degradation of the battery is estimated as the difference between the first and second strain measurements divided by the first strain measurement.

  15. Hierarchical three-dimensional porous SnS{sub 2}/carbon cloth anode for high-performance lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Junfeng, E-mail: chchjjff@163.com [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China); Zhang, Xiutai [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China); Xing, Shumin [College of Mathematics and Physics, Anyang Institute of Technology, Anyang 455000 (China); Fan, Qiufeng; Yang, Junping; Zhao, Luhua; Li, Xiang [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China)

    2016-08-15

    Graphical abstract: Hierarchical 3D porous SnS{sub 2}/carbon cloth, good electrochemical performance. - Highlights: • Hierarchical 3D porous SnS{sub 2}/carbon cloth has been firstly synthesized. • The SnS{sub 2}/carbon clothes were good candidates for excellent lithium ion batteries. • The SnS{sub 2}/carbon cloth exhibits improved capacity compared to pure SnS{sub 2}. - Abstract: Hierarchical three-dimension (3D) porous SnS{sub 2}/carbon clothes were synthesized via a facile polyol refluxing process. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmet–Teller (BET) and UV–vis diffuse reflectance spectrometer (UV–vis DRS). The 3D porous SnS{sub 2}/carbon clothes-based lithium ion batteries exhibited high reversible capacity and good rate capability as anode materials. The good electrochemical performance for lithium ion storage could be attributed to the special nanostructure, leading to high-rate transportation of electrolyte ion and electrons throughout the electrode matrix.

  16. A facile and scalable method to prepare carbon nanotube-grafted-graphene for high performance Li-S battery

    Science.gov (United States)

    Wang, Q. Q.; Huang, J. B.; Li, G. R.; Lin, Z.; Liu, B. H.; Li, Z. P.

    2017-01-01

    A carbon nanotube-grafted-graphene (CNT-g-Gr) is developed for enhancements of electrical conduction and polysulfide (PS) absorption to improve rate performance and cycleability of lithium-sulfur battery. The CNT-g-Gr is prepared through CNT growth on Ni-deposited graphene sheet which is fabricated via pyrolysis of glucose in a molten salt. The obtained CNT-g-Gr shows much higher specific surface area and PS adsorption capability than graphene. The in-situ formed Ni nanoparticles on graphene sheet not only serve as the catalytic sites for CNT growth, but also function as the anchor-sites for polar PS absorption. The CNT-g-Gr contributes a superb PS adsorption capability arising from graphene and CNT absorbing weakly-polar PS species, and Ni nanoparticles absorbing the species with stronger polarity. The resultant Li-S battery with the CNT-g-Gr shows excellent cycleability and rate performance. A stable discharge capacity of 900 mAh g-1 (with low capacity degradation rate) and a rate capacity of 260 mAh g-1 at 30 C discharge rate have been achieved.

  17. Effect of wrinkles on electrochemical performance of multiwalled carbon nanotubes as anode material for Li ion battery

    International Nuclear Information System (INIS)

    Sahoo, Madhumita; Ramaprabhu, S.

    2015-01-01

    Highlights: • Wrinkly surfaced gC is employed as anode material for Li ion battery. • Temperature controlled protrusions were uniformly distributed over the nanotubes. • gC shows superior performance of 373 mAh g −1 at 100 mA g −1 after 150 cycle. • Synergistic effect of defects and conductivity gives higher Li storage over MWNTs. - Abstract: A 1-D monohybrid of multiwalled carbon nanotubes and graphene sheets, graphene wrapped multiwalled carbon nanotubes (gC) structure, synthesized in a template-free simple chemical vapor deposition technique without any chemical functionalization, was employed as efficient anode material for Li ion battery. Graphene nanosheets affixed to the multiwalled carbon nanotubes (MWNTs) surface by van der Waal's attraction gives a wrinkled surface to the final 1-D gC configuration. The protrusions on the surface of the tube enhances the porosity of the system and also acts as defects, enhancing lithium adsorption sites while the inner MWNT core gives high electrical conductivity, resulting enhanced electrochemical performance of 373 mAh g −1 at 100 mA g −1 current density after 150 cycles.

  18. Mesoporous LiMnPO4/C nanoparticles as high performance cathode material for lithium ion batteries

    International Nuclear Information System (INIS)

    Wen, Fang; Shu, Hongbo; Zhang, Yuanyuan; Wan, Jiajia; Huang, Weihua; Yang, Xiukang; Yu, Ruizhi; Liu, Li; Wang, Xianyou

    2016-01-01

    LiMnPO 4 has been considered as one of the most promising high voltage cathode materials for next-generation lithium ion batteries. However, LiMnPO 4 suffers from intrinsic drawbacks of extremely low electronic conductivity and ionic diffusivity between LiMnPO 4 /MnPO 4 . In this paper, mesoporous LiMnPO 4 nanoparticles are synthesized successfully via a facile glycine-assisted solvothermal rout. The as-prepared mesoporous LiMnPO 4 /C nanoparticles present well-defined abundant mesoporous structure (diameter of 3 ∼ 10 nm), uniform carbon layer (thickness of 3 ∼ 4 nm), high specific surface area (90.1 m 2 /g). As a result, the mesoporous LiMnPO 4 /C nanoparticles achieve excellent electrochemical performance as cathode materials for lithium ion batteries. It demonstrates a high discharge capacity of 167.7, 161.6, 156.4, 148.4 and 128.7 mAh/g at 0.1, 0.5, 1, 2 and 5C, and maintains a discharge capacity of 130.0 mAh/g after 100 cycles at 1C. The good electrochemical performance is attributed to its special interpenetrating mesoporous structure in LiMnPO 4 nanoparticles, which significantly enhances the ionic and electronic transport and additional capacitive behavior to compensate the sluggish kinetics.

  19. High-Performance Lithium-Oxygen Battery Electrolyte Derived from Optimum Combination of Solvent and Lithium Salt.

    Science.gov (United States)

    Ahn, Su Mi; Suk, Jungdon; Kim, Do Youb; Kang, Yongku; Kim, Hwan Kyu; Kim, Dong Wook

    2017-10-01

    To fabricate a sustainable lithium-oxygen (Li-O 2 ) battery, it is crucial to identify an optimum electrolyte. Herein, it is found that tetramethylene sulfone (TMS) and lithium nitrate (LiNO 3 ) form the optimum electrolyte, which greatly reduces the overpotential at charge, exhibits superior oxygen efficiency, and allows stable cycling for 100 cycles. Linear sweep voltammetry (LSV) and differential electrochemical mass spectrometry (DEMS) analyses reveal that neat TMS is stable to oxidative decomposition and exhibit good compatibility with a lithium metal. But, when TMS is combined with typical lithium salts, its performance is far from satisfactory. However, the TMS electrolyte containing LiNO 3 exhibits a very low overpotential, which minimizes the side reactions and shows high oxygen efficiency. LSV-DEMS study confirms that the TMS-LiNO 3 electrolyte efficiently produces NO 2 - , which initiates a redox shuttle reaction. Interestingly, this NO 2 - /NO 2 redox reaction derived from the LiNO 3 salt is not very effective in solvents other than TMS. Compared with other common Li-O 2 solvents, TMS seems optimum solvent for the efficient use of LiNO 3 salt. Good compatibility with lithium metal, high dielectric constant, and low donicity of TMS are considered to be highly favorable to an efficient NO 2 - /NO 2 redox reaction, which results in a high-performance Li-O 2 battery.

  20. The effects of element Cu on the electrochemical performances of Zinc-Aluminum-hydrotalcites in Zinc/Nickel secondary battery

    International Nuclear Information System (INIS)

    Wen, Xing; Yang, Zhanhong; Xie, Xiaoe; Feng, Zhaobin; Huang, Jianhang

    2015-01-01

    Zn-Cu-Al-CO_3 layered double hydroxides (LDHs) have been successfully synthesized by using the method of constant pH co-precipitation. And it also has been proposed as a novel anodic material in Zinc-Nickel secondary batteries. The X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images of the as-prepared sample exhibit that the samples are well crystallized and have hexagon structure. The electrochemical performances of Zn-Al-LDHs and Zn-Cu-Al-LDHs with different Zn/Cu/Al molar ratios are investigated by the measurements such as galvanostatic charge-discharge, cyclic voltammogram and electrochemical impedance spectroscopy (EIS). Comparing with the pure Zn-Al-LDHs, Zn-Cu-Al-LDHs show more stable cycling performance, exhibit better reversibility and display lower charge-transfer resistance. Especially, the Zn-Cu-Al-LDHs with the Zn/Cu/Al molar ratio being 2.8:0.2:1 exhibits the best electrochemical properties than other samples. After 800 cell cycles, the specific discharge capacity of Zn-Cu-Al-LDHs with the Zn/Cu/Al molar ratio of 2.8:0.2:1is 345 mA h g"−"1, while that of pure Zn-Al-LDHs is only 177 mA h g"−"1. Based on these observations, the prepared Zn-Cu-Al-LDHs may be a promising anode active material for Zinc/Nickel secondary batteries.

  1. Graphene-Armored Aluminum Foil with Enhanced Anticorrosion Performance as Current Collectors for Lithium-Ion Battery.

    Science.gov (United States)

    Wang, Mingzhan; Tang, Miao; Chen, Shulin; Ci, Haina; Wang, Kexin; Shi, Liurong; Lin, Li; Ren, Huaying; Shan, Jingyuan; Gao, Peng; Liu, Zhongfan; Peng, Hailin

    2017-12-01

    Aluminum (Al) foil, as the most accepted cathode current collector for lithium-ion batteries (LIBs), is susceptible to local anodic corrosions during long-term operations. Such corrosions could lead to the deterioration or even premature failure of the batteries and are generally believed to be a bottleneck for next-generation 5 V LIBs. Here, it is demonstrated that Al foil armored by conformal graphene coating exhibits significantly reinforced anodic corrosion resistance in both LiPF 6 and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI) based electrolytes. Moreover, LiMn 2 O 4 cells using graphene-armored Al foil as current collectors (LMO/GA) demonstrate enhanced electrochemical performance in comparison with those using pristine Al foil (LMO/PA). The long-term discharge capacity retention of LMO/GA cell after ≈950 h straight operations at low rate (0.5 C) reaches up to 91%, remarkably superior to LMO/PA cell (75%). The self-discharge propensity of LMO/GA is clearly relieved and the rate/power performance is also improved with graphene mediations. This work not only contributes to the long-term stable operations of LIBs but also might catalyze the deployment of 5 V LIBs in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Interconnected α-Fe2O3 nanosheet arrays as high-performance anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Cai, Dandan; Li, Dongdong; Ding, Liang-Xin; Wang, Suqing; Wang, Haihui

    2016-01-01

    The electrode materials with structure stability and binder-free are urgently required for improving the electrochemical performance of lithium-ion batteries. In this work, interconnected α-Fe 2 O 3 nanosheet arrays directly grown on Ti foil were fabricated via a facile galvanostatic electrodeposition method followed by thermal treatment. The as-prepared α-Fe 2 O 3 has an open network structure constituted of interconnected nanosheets and can be directly used as integrated electrodes for lithium-ion batteries. The α-Fe 2 O 3 nanosheet arrays exhibit a high reversible capacity of 986.3 mAh g −1 at a current density of 100 mA g −1 . Moreover, a reversible capacity of ca. 425.9 mAh g −1 is achieved even at a superhigh current density of 10 A g −1 , which is higher than the theoretical capacity of commercially used graphite. The excellent performance could be attributed to the efficient electron transport, the large electrode/electrolyte interfaces and the good accommodations for volume expansion from the interconnected nanosheet arrays structure.

  3. Battery Thermal Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, Matthew A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-08

    The operating temperature is critical in achieving the right balance between performance, cost, and life for both Li-ion batteries and ultracapacitors. The chemistries of advanced energy-storage devices - such as lithium-based batteries - are very sensitive to operating temperature. High temperatures degrade batteries faster while low temperatures decrease their power and capacity, affecting vehicle range, performance, and cost. Understanding heat generation in battery systems - from the individual cells within a module, to the inter-connects between the cells, and across the entire battery system - is imperative for designing effective thermal-management systems and battery packs. At NREL, we have developed unique capabilities to measure the thermal properties of cells and evaluate thermal performance of battery packs (air or liquid cooled). We also use our electro-thermal finite element models to analyze the thermal performance of battery systems in order to aid battery developers with improved thermal designs. NREL's tools are used to meet the weight, life, cost, and volume goals set by the U.S. Department of Energy for electric drive vehicles.

  4. Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate

    Science.gov (United States)

    Kamman, J. H.; Hall, C. L.

    1975-01-01

    Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

  5. An efficient route to Cu_2O nanorod array film for high-performance Li-ion batteries

    International Nuclear Information System (INIS)

    Yang, Yumei; Wang, Kun; Yang, Zeheng; Zhang, Yingmeng; Gu, Heyun; Zhang, Weixin; Li, Errui; Zhou, Chen

    2016-01-01

    Fabrication of well-organized one-dimensional nanostructured arrays on conducting substrates as binder free electrodes allows us to synergize and integrate multi-functionalities into lithium ion batteries. In this contribution, we report a metal-induced thermal reduction (MITR) method to prepare free-standing Cu_2O nanorod array film with average diameters of 400 ± 100 nm and lengths of several microns on copper substrates by direct thermal reduction of Cu(OH)_2 nanorod arrays on copper foils in nitrogen atmosphere at 500 °C. The presence of Cu substrates reduces the Cu(OH)_2 to Cu_2O and decreases the reduction temperature significantly through changing the reaction Gibbs energy. Compared with some previously-reported methods about thermal reduction, the MITR method is facile, controllable, efficient and low energy consumption. The free-standing Cu_2O nanorod array film on Cu substrates as anode can achieve high rate capability (315 mAh g"−"1 at 10 C) and good cyclability (358 mAh g"−"1 after 200 cycles at 1 C), demonstrating their excellent electrochemical performance in lithium ion batteries, which results from relatively faster electron and ion transport, easier electrolyte diffusion and better accommodation of strains from the repeated conversion reactions based on their one-dimensional nanostructured arrays. - Highlights: • A metal-induced thermal reduction method was used to prepare Cu_2O nanorod array film. • Copper substrate takes an important part in the conversion of Cu(OH)_2 to Cu_2O. • The Cu_2O films show excellent electrochemical properties as anode for Li-ion battery.

  6. SnS2 nanoflakes decorated multiwalled carbon nanotubes as high performance anode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    Sun, Hongyu; Ahmad, Mashkoor; Luo, Jun; Shi, Yingying; Shen, Wanci; Zhu, Jing

    2014-01-01

    Graphical abstract: The synthesized SnS 2 nanoflakes decorated multiwalled carbon nanotubes hybrid structures exhibit large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS 2 nanoflakes. - Highlights: • Synthesis of SnS 2 nanoflakes decorated multiwalled carbon nanotubes hybrid structures. • Simple solution-phase approach. • Morphology feature of SnS 2 . • Enhanced performance as Li-ion batteries. - Abstract: SnS 2 nanoflakes decorated multiwalled carbon nanotubes (MWCNTs) hybrid structures are directly synthesized via a simple solution-phase approach. The as-prepared SnS 2 /MWCNTs structures are investigated as anode materials for Li-ion batteries as compared with SnS 2 nanoflakes. It has been found that the composite structure exhibit excellent lithium storage performance with a large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS 2 nanoflakes. The first discharge and charge capacities have been found to be 1416 and 518 mA h g −1 for SnS 2 /MWCNTs composite electrodes at a current density of 100 mA g −1 between 5 mV and 1.15 V versus Li/Li + . A stable reversible capacity of ∼510 mA h g −1 is obtained for 50 cycles. The improved electrochemical performance may be attributed to the flake-morphology feature of SnS 2 and the addition of MWCNTs that can hinder the agglomeration of the active materials and improve the conductivity of the composite electrode simultaneously

  7. SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes as high performance anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hongyu [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Ahmad, Mashkoor, E-mail: mashkoorahmad2003@yahoo.com [Nanomaterials Research Group (NRG), Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); Luo, Jun [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Shi, Yingying; Shen, Wanci [Laboratory of Advanced Materials, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China); Zhu, Jing, E-mail: jzhu@mail.tsinghua.edu.cn [Beijing National Center for Electron Microscopy, The State Key Laboratory of New Ceramics and Fine Processing, Department of Material Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2014-01-01

    Graphical abstract: The synthesized SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes hybrid structures exhibit large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS{sub 2} nanoflakes. - Highlights: • Synthesis of SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes hybrid structures. • Simple solution-phase approach. • Morphology feature of SnS{sub 2}. • Enhanced performance as Li-ion batteries. - Abstract: SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes (MWCNTs) hybrid structures are directly synthesized via a simple solution-phase approach. The as-prepared SnS{sub 2}/MWCNTs structures are investigated as anode materials for Li-ion batteries as compared with SnS{sub 2} nanoflakes. It has been found that the composite structure exhibit excellent lithium storage performance with a large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS{sub 2} nanoflakes. The first discharge and charge capacities have been found to be 1416 and 518 mA h g{sup −1} for SnS{sub 2}/MWCNTs composite electrodes at a current density of 100 mA g{sup −1} between 5 mV and 1.15 V versus Li/Li{sup +}. A stable reversible capacity of ∼510 mA h g{sup −1} is obtained for 50 cycles. The improved electrochemical performance may be attributed to the flake-morphology feature of SnS{sub 2} and the addition of MWCNTs that can hinder the agglomeration of the active materials and improve the conductivity of the composite electrode simultaneously.

  8. Cognitive performance in relapsing remitting multiple sclerosis: A longitudinal study in daily practice using a brief computerized cognitive battery

    Directory of Open Access Journals (Sweden)

    Jacquerye Philippe

    2011-06-01

    Full Text Available Abstract Background There is need for a cognitive test battery that can be easily used in clinical practice to detect or monitor cognitive performance in patients with multiple sclerosis (MS. In order to conduct, in this patient group, a preliminary investigation of the validity and utility of a brief computerized battery, the Cognitive Drug Research (CDR battery, we longitudinally assessed cognition in patients with relapsing remitting (RR MS. Methods Forty-three mildly disabled, clinically active RRMS patients were repeatedly assessed with the Digit Symbol Substitution Test (DSST, Paced Auditory Serial Addition Test (PASAT and five composite scores derived from the CDR computerized cognitive test system (CDR System: Power of Attention, Continuity of Attention, Quality of Working Memory, Quality of Episodic Memory and Speed of Memory. The Multiple Sclerosis Functional Composite (MSFC and Expanded Disability Status Scale (EDSS measured disability. Results The composite scores from the CDR battery generally showed excellent test-retest reliability over the repeated assessments, though was low on occasions for the Quality of Working Memory and Quality of Episodic Memory measures. The CDR measures tended to be highly correlated with other measures of cognition (DSST and PASAT and were also strongly related to disability (EDSS and MSFC. Baseline scores indicated large impairments to visual information processing speed and attention (DSST, Cohen's d 1.1; Power of Attention d 1.4 [reaction time on tasks of focussed and sustained attention], and a moderate impairment both to sustained attention (Continuity of Attention d 0.6 and complex information processing speed (Speed of memory d 0.7 [reaction time on tasks of working and episodic Memory], when compared to normative data derived from healthy volunteers enrolled in a series of separate, prior clinical trials. Working memory (Quality of Working Memory and episodic memory (Quality of Episodic Memory

  9. Improving the performance of soft carbon for lithium-ion batteries

    International Nuclear Information System (INIS)

    Chen Zonghai; Wang Qingzheng; Amine, K.

    2006-01-01

    A novel technique for designing a robust solid electrolyte interface (SEI) on the negative electrodes of lithium-ion batteries has been developed using a silane coating. Two silane compounds, 3,3,3-trifluoropropyltrimethoxysilane (TFPTMS) and dimethoxybis(2-(2-(2-mothoxyethoxy)ethoxy)ethoxy)silane (1ND3(MeO)), have been investigated with respect to improving the capacity retention of lithium manganese oxide spinel/soft carbon cells. The impact of the silane coating on the soft carbon electrode will be attributed to (1) changes in surface functional groups (2) compositional change of the SEI, and (3) changes in the kinetics of manganese deposition. The impact of the upper cutoff voltage on the capacity retention of the cell was also discussed

  10. Hydrothermal synthesis of nickel oxide nanosheets for lithium-ion batteries and supercapacitors with excellent performance.

    Science.gov (United States)

    Mondal, Anjon Kumar; Su, Dawei; Wang, Ying; Chen, Shuangqiang; Wang, Guoxiu

    2013-11-01

    Nickel oxide nanosheets have been successfully synthesized by a facile ethylene glycol mediated hydrothermal method. The morphology and crystal structure of the nickel oxide nanosheets were characterized by X-ray diffraction, field-emission SEM, and TEM. When applied as electrode materials for lithium-ion batteries and supercapacitors, nickel oxide nanosheets exhibited a high, reversible lithium storage capacity of 1193 mA h g(-1) at a current density of 500 mA g(-1), an enhanced rate capability, and good cycling stability. Nickel oxide nanosheets also demonstrated a superior specific capacitance of 999 F g(-1) at a current density of 20 A g(-1) in supercapacitors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Improvement of Aluminum-Air Battery Performances by the Application of Flax Straw Extract.

    Science.gov (United States)

    Grishina, Ekaterina; Gelman, Danny; Belopukhov, Sergey; Starosvetsky, David; Groysman, Alec; Ein-Eli, Yair

    2016-08-23

    The effect of a flax straw extract on Al corrosion inhibition in a strong alkaline solution was studied by using electrochemical measurements, weight-loss analysis, SEM, and FTIR spectroscopy. Flax straw extract added (3 vol %) to the 5 m KOH solution to act as a mixed-type Al corrosion inhibitor. The electrochemistry of Al in the presence of a flax straw extract in the alkaline solution, the effect of the extract on the Al morphology and surface films formed, and the corrosion inhibition mechanism are discussed. Finally, the Al-air battery discharge capacity recorded from a cell that used the flax straw extract in the alkaline electrolyte is substantially higher than that with only a pure alkaline electrolyte. This improved sustainability of the Al anode is attributed to Al corrosion inhibition and, consequently, to hydrogen evolution suppression. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Nb2O5 hollow nanospheres as anode material for enhanced performance in lithium ion batteries

    International Nuclear Information System (INIS)

    Sasidharan, Manickam; Gunawardhana, Nanda; Yoshio, Masaki; Nakashima, Kenichi

    2012-01-01

    Graphical abstract: Nb 2 O 5 hollow nanosphere constructed electrode delivers high capacity of 172 mAh g −1 after 250 cycles and maintains structural integrity and excellent cycling stability. Highlights: ► Nb 2 O 5 hollow nanospheres synthesis was synthesized by soft-template. ► Nb 2 O 5 hollow nanospheres were investigated as anode material in Li-ion battery. ► Nanostructured electrode delivers high capacity of 172 mAh g −1 after 250 cycles. ► The electrode maintains the structural integrity and excellent cycling stability. ► Nanosized shell domain facilitates fast lithium intercalation/deintercalation. -- Abstract: Nb 2 O 5 hollow nanospheres of average diameter ca. ∼29 nm and hollow cavity size ca. 17 nm were synthesized using polymeric micelles with core–shell–corona architecture under mild conditions. The hollow particles were thoroughly characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermal (TG/DTA) and nitrogen adsorption analyses. Thus obtained Nb 2 O 5 hollow nanospheres were investigated as anode materials for lithium ion rechargeable batteries for the first time. The nanostructured electrode delivers high capacity of 172 mAh g −1 after 250 cycles of charge/discharge at a rate of 0.5 C. More importantly, the hollow particles based electrodes maintains the structural integrity and excellent cycling stability even after exposing to high current density 6.25 A g −1 . The enhanced electrochemical behavior is ascribed to hollow cavity coupled with nanosized Nb 2 O 5 shell domain that facilitates fast lithium intercalation/deintercalation kinetics.

  13. Recent Progresses and Development of Advanced Atomic Layer Deposition towards High-Performance Li-Ion Batteries

    Science.gov (United States)

    Lu, Wei; Liang, Longwei; Sun, Xuan; Sun, Xiaofei; Wu, Chen; Hou, Linrui; Sun, Jinfeng

    2017-01-01

    Electrode materials and electrolytes play a vital role in device-level performance of rechargeable Li-ion batteries (LIBs). However, electrode structure/component degeneration and electrode-electrolyte sur-/interface evolution are identified as the most crucial obstacles in practical applications. Thanks to its congenital advantages, atomic layer deposition (ALD) methodology has attracted enormous attention in advanced LIBs. This review mainly focuses upon the up-to-date progress and development of the ALD in high-performance LIBs. The significant roles of the ALD in rational design and fabrication of multi-dimensional nanostructured electrode materials, and finely tailoring electrode-electrolyte sur-/interfaces are comprehensively highlighted. Furthermore, we clearly envision that this contribution will motivate more extensive and insightful studies in the ALD to considerably improve Li-storage behaviors. Future trends and prospects to further develop advanced ALD nanotechnology in next-generation LIBs were also presented. PMID:29036916

  14. Silver-nickel oxide core-shell nanoflower arrays as high-performance anode for lithium-ion batteries

    Science.gov (United States)

    Zhao, Wenjia; Du, Ning; Zhang, Hui; Yang, Deren

    2015-07-01

    We demonstrate the synthesis of Ag-NiO core-shell nanoflower arrays via a one-step solution-immersion process and subsequent RF-sputtering method. The aligned Ag nanoflower arrays on copper substrate are prepared by a facile displacement reaction in absence of any surfactant at a mild temperature. When used as anode materials for lithium-ion batteries, the Ag-NiO core-shell nanoflower arrays show better cycling performance and higher capacity than the planar NiO electrodes. The improved performance should be attributed to the core-shell structures that can enhance the conductivity and accommodate the volume change during the charge-discharge process.

  15. Effect of electrode intrusion on pressure drop and electrochemical performance of an all-vanadium redox flow battery

    Science.gov (United States)

    Kumar, S.; Jayanti, S.

    2017-08-01

    In this paper, we present a study of the effect of electrode intrusion into the flow channel in an all-vanadium redox flow battery. Permeability, pressure drop and electrochemical performance have been measured in a cell with active area 100 cm2and 414 cm2 fitted with a carbon felt electrode of thickness of 3, 6 or 9 mm compressed to 1.5, 2.5 or 4 mm, respectively, during assembly. Results show that the pressure drop is significantly higher than what can be expected in the thick electrode case while its electrochemical performance is lower. Detailed flow analysis using computational fluid dynamics simulations in two different flow fields shows that both these results can be attributed to electrode intrusion into the flow channel leading to increased resistance to electrolyte flow through the electrode. A correlation is proposed to evaluate electrode intrusion depth as a function of compression.

  16. Improved battery performance using Pd nanoparticles synthesized on the surface of LiFePO4/C by ultrasound irradiation

    Science.gov (United States)

    Saliman, Muhammad Ali; Okawa, Hirokazu; Takai, Misaki; Ono, Yuki; Kato, Takahiro; Sugawara, Katsuyasu; Sato, Mineo

    2016-07-01

    LiFePO4 has been attracting interest as a cathode material for Li-ion batteries due to its high energy density, low cost, and eco-friendliness. The electrochemical performance of LiFePO4 is limited because it exhibits low Li-ion diffusivity and low electronic conductivity. Numerous solutions have been considered, such as carbon coating, which is widely known to improve the electronic conductivity of LiFePO4. The deposition of metal nanoparticles (NPs) on the surface of carbon-coated LiFePO4 further enhances the electronic conductivity. In this study, we deposited Pd NPs onto the surface of LiFePO4/C and investigated the resulting electrochemical performance. Sonochemical synthesis was used to prepare the metal NPs; the procedure did not require any surfactants and the reaction was rapid.

  17. Battery Modeling

    NARCIS (Netherlands)

    Jongerden, M.R.; Haverkort, Boudewijn R.H.M.

    2008-01-01

    The use of mobile devices is often limited by the capacity of the employed batteries. The battery lifetime determines how long one can use a device. Battery modeling can help to predict, and possibly extend this lifetime. Many different battery models have been developed over the years. However,

  18. Lithium Batteries

    Science.gov (United States)

    National Laboratory, Materials Science and Technology Division Lithium Batteries Resources with Additional thin-film lithium batteries for a variety of technological applications. These batteries have high essentially any size and shape. Recently, Teledyne licensed this technology from ORNL to make batteries for

  19. A case study of different configurations for the performance analysis of solid oxide fuel cells with external reformers

    International Nuclear Information System (INIS)

    Lee, Kang Hun; Woo, Hyun Tak; Yu, Sang Seok; Lee, Sang Min; Lee, Young Duk; Kang, Sang Gyu; Ahn, Kook Young

    2012-01-01

    A planar solid oxide fuel cell (PSOFC) is studied in its application in a high temperature stationary power plant. Even though PSOFCs with external reformers are designed for application from the distributed power source to the central power plant, such PSOFCs may sacrifice more system efficiency than internally reformed SOFCs. In this study, modeling of the PSOFC with an external reformer was developed to analyze the feasibility of thermal energy utilization for the external reformer. The PSOFC system model includes the stack, reformer, burner, heat exchanger, blower, pump, PID controller, 3-way valve, reactor, mixer, and steam separator. The model was developed under the Matlab/Simulink environment with Thermolib'R'modules. The model was used to study the system performance according to its configuration. Three configurations of the SOFC system were selected for the comparison of the system performance. The system configuration considered the cathode recirculation, thermal sources for the external reformer, heat up of operating gases, and condensate anode off gas for the enhancement of the fuel concentration. The simulation results show that the magnitude of the electric efficiency of the PSOFC system for Case 2 is 12.13% higher than that for Case 1 (reference case), and the thermal efficiency of the PSOFC system for Case 3 is 76.12%, which is the highest of all the cases investigated

  20. An Ultrastable and High-Performance Flexible Fiber-Shaped Ni-Zn Battery based on a Ni-NiO Heterostructured Nanosheet Cathode.

    Science.gov (United States)

    Zeng, Yinxiang; Meng, Yue; Lai, Zhengzhe; Zhang, Xiyue; Yu, Minghao; Fang, Pingping; Wu, Mingmei; Tong, Yexiang; Lu, Xihong

    2017-11-01

    Currently, the main bottleneck for the widespread application of Ni-Zn batteries is their poor cycling stability as a result of the irreversibility of the Ni-based cathode and dendrite formation of the Zn anode during the charging-discharging processes. Herein, a highly rechargeable, flexible, fiber-shaped Ni-Zn battery with impressive electrochemical performance is rationally demonstrated by employing Ni-NiO heterostructured nanosheets as the cathode. Benefiting from the improved conductivity and enhanced electroactivity of the Ni-NiO heterojunction nanosheet cathode, the as-fabricated fiber-shaped Ni-NiO//Zn battery displays high capacity and admirable rate capability. More importantly, this Ni-NiO//Zn battery shows unprecedented cyclic durability both in aqueous (96.6% capacity retention after 10 000 cycles) and polymer (almost no capacity attenuation after 10 000 cycles at 22.2 A g -1 ) electrolytes. Moreover, a peak energy density of 6.6 µWh cm -2 , together with a remarkable power density of 20.2 mW cm -2 , is achieved by the flexible quasi-solid-state fiber-shaped Ni-NiO//Zn battery, outperforming most reported fiber-shaped energy-storage devices. Such a novel concept of a fiber-shaped Ni-Zn battery with impressive stability will greatly enrich the flexible energy-storage technologies for future portable/wearable electronic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Flexible carbon nanofiber/polyvinylidene fluoride composite membranes as interlayers in high-performance Lithiumsbnd Sulfur batteries

    Science.gov (United States)

    Wang, Zhenhua; Zhang, Jing; Yang, Yuxiang; Yue, Xinyang; Hao, Xiaoming; Sun, Wang; Rooney, David; Sun, Kening

    2016-10-01

    Traditionally polyvinylidene fluoride membranes have been used in applications such as membrane distillation, wastewater treatment, desalination and separator fabrication. Within this work we demonstrate that a novel carbon nanofiber/polyvinylidene fluoride (CNF/PVDF) composite membrane can be used as an interlayer for Lithiumsbnd Sulfur (Lisbnd S) batteries yielding both high capacity and long cycling life. This PVDF membrane is shown to effectively separate dissolved lithium polysulfide with the high electronic conductivity CNF not only reducing the internal resistance in the sulfur cathode but also helping immobilize the polysulfide through its abundant nanospaces. The resulting Lisbnd S battery assembled with the CNF/PVDF composite membrane effectively solves the polysulfide permeation problem and exhibits excellent electrochemical performance. It is further shown that the CNF/PVDF electrode has an excellent cycling stability and retains a capacity of 768.6 mAh g-1 with a coulombic efficiency above 99% over 200 cycles at 0.5C, which is more than twice that of a cell without CNF/PVDF (374 mAh g-1). In addition, the low-cost raw materials and the simple preparation process of CNF/PVDF composite membrane is also amenable for industrial production.

  2. Highly nitrogen-doped carbon capsules: scalable preparation and high-performance applications in fuel cells and lithium ion batteries.

    Science.gov (United States)

    Hu, Chuangang; Xiao, Ying; Zhao, Yang; Chen, Nan; Zhang, Zhipan; Cao, Minhua; Qu, Liangti

    2013-04-07

    Highly nitrogen-doped carbon capsules (hN-CCs) have been successfully prepared by using inexpensive melamine and glyoxal as precursors via solvothermal reaction and carbonization. With a great promise for large scale production, the hN-CCs, having large surface area and high-level nitrogen content (N/C atomic ration of ca. 13%), possess superior crossover resistance, selective activity and catalytic stability towards oxygen reduction reaction for fuel cells in alkaline medium. As a new anode material in lithium-ion battery, hN-CCs also exhibit excellent cycle performance and high rate capacity with a reversible capacity of as high as 1046 mA h g(-1) at a current density of 50 mA g(-1) after 50 cycles. These features make the hN-CCs developed in this study promising as suitable substitutes for the expensive noble metal catalysts in the next generation alkaline fuel cells, and as advanced electrode materials in lithium-ion batteries.

  3. A natural carbonized leaf as polysulfide diffusion inhibitor for high-performance lithium-sulfur battery cells.

    Science.gov (United States)

    Chung, Sheng-Heng; Manthiram, Arumugam

    2014-06-01

    Attracted by the unique tissue and functions of leaves, a natural carbonized leaf (CL) is presented as a polysulfide diffusion inhibitor in lithium-sulfur (Li-S) batteries. The CL that is covered on the pure sulfur cathode effectively suppresses the polysulfide shuttling mechanism and enables the use of pure sulfur as the cathode. A low charge resistance and a high discharge capacity of 1320 mA h g(-1) arise from the improved cell conductivity due to the innately integral conductive carbon network of the CL. The unique microstructure of CL leads to a high discharge/charge efficiency of >98 %, low capacity fade of 0.18 % per cycle, and good long-term cyclability over 150 cycles. The structural gradient and the micro/mesoporous adsorption sites of CL effectively intercept/trap the migrating polysulfides and facilitate their reutilization. The green CL polysulfide diffusion inhibitor thus offers a viable approach for developing high-performance lithium-sulfur batteries. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S., E-mail: ramp@iitm.ac.in

    2015-01-15

    Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.

  5. Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

    International Nuclear Information System (INIS)

    Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S.

    2015-01-01

    Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g −1 at 100 mA g −1 after 30th cycles. At high current density value of 1 A g −1 , B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states

  6. Preparation of octahedral CuO micro/nanocrystals and electrochemical performance as anode for lithium-ion battery

    International Nuclear Information System (INIS)

    Feng, Lili; Xuan, Zhewen; Bai, Yang; Zhao, Hongbo; Li, Li; Chen, Yashun; Yang, Xianqin; Su, Changwei; Guo, Junming; Chen, Xiaokai

    2014-01-01

    Highlights: • Octahedral cupric oxides with hollow structure were prepared. • No hard template was used in the preparation of hollow cupric oxides. • The cupric oxides show good reversible capacity. - Abstract: Herein we report that three octahedral CuO samples with hollow or solid structure are successfully prepared by firstly preparation of Cu 2 O products using a chemical reduction method, then by calcination in a muffle furnace at 300 °C for 3 h in air atmosphere. The obtained CuO samples serve as a good model system for the study as anodes for lithium ion batteries. All the three CuO samples have high discharge specific capacity and good cycling stability from the 2nd cycling to the 50th cycling. Octahedral CuO hollow crystals with 400 nm in size have the highest reversible capacity and the smallest resistance. So their electrochemical performances are partly related to their morphologies. The results suggest that the as-prepared CuO samples, especially the 400 nm hollow octahedral CuO crystals could be a promising material for the anode of lithium-ion battery

  7. Improvement of lithium-ion battery performance at low temperature by adopting polydimethylsiloxane-based electrolyte additives

    International Nuclear Information System (INIS)

    Kim, Kwang Man; Ly, Nguyen Vu; Won, Jung Ha; Lee, Young-Gi; Cho, Won Il; Ko, Jang Myoun; Kaner, Richard B.

    2014-01-01

    Three kinds of polydimethylsiloxane (PDMS)-based grafted and ungrafted copolymers such as poly[dimethylsiloxane-co-(siloxane-g-acrylate)] (PDMS-A), poly(dimethylsiloxane-co-phenylsiloxane) (PDMS-P), and poly[dimethylsiloxane-co-(siloxane-g-ethylene oxide)] (PDMS-EO) are used as additives to standard liquid electrolyte solutions to enhance the lithium-ion battery performance at low temperatures. Liquid electrolyte solutions with PDMS-based additives are electrochemically stable under 5.0 V and have adequate ionic conductivities of 10 −4 S cm −1 at -20 °C. Particularly, liquid electrolytes with PDMS-P and PDMS-EO exhibit higher ionic conductivities of around 5 × 10 −4 S cm −1 at -20 °C, indicating a specific resisting property against the freezing of the liquid electrolyte components. As a result, the addition of PDMS-based additives to liquid electrolytes improves the capacity retention ratio and rate-capability of lithium-ion batteries at low temperatures

  8. Enhanced cycle performance of Li/S battery with the reduced graphene oxide/activated carbon functional interlayer

    Institute of Scientific and Technical Information of China (English)

    Haipeng Li; Liancheng Sun; Yongguang Zhang; Taizhe Tan; Gongkai Wang; Zhumabay Bakenov

    2017-01-01

    The high-energy lithium/sulfur (Li/S) battery has become a very popular topic of research in recent years due to its high theoretical capacity of 1672 mAh/g.However,the polysulfide shuttle effect remains of great concern with a great number of publications dedicated to its mitigation.In this contribution,a three-dimensional (3D) reduced graphene oxide/activated carbon (RGO/AC) film,synthesized by a simple hydrothermal method and convenient mechanical pressing,is sandwiched between the separator and the sulfur-based cathode,acting as a functional interlayer to capture and trap polysulfide species.Consequently,the Li/S cell with this interlayer shows an impressive initial discharge capacity of 1078 mAh/g and a reversible capacity of 655 mAh/g even after 100 cycles.The RGO/AC interlayer impedes the movement of polysulfide while providing unimpeded channels for lithium ion mass transfer.Therefore,the RGO/AC interlayer with a well-designed structure represents strong potential for high-performance Li/S batteries.

  9. Modeling and simulation performance of photovoltaic system integration battery and supercapacitor paralellization of MPPT prototipe for solar vehicle

    Science.gov (United States)

    Ajiatmo, Dwi; Robandi, Imam

    2017-03-01

    This paper proposes a control scheme photovoltaic, battery and super capacitor connected in parallel for use in a solar vehicle. Based on the features of battery charging, the control scheme consists of three modes, namely, mode dynamic irradian, constant load mode and constant voltage charging mode. The shift of the three modes can be realized by controlling the duty cycle of the mosffet Boost converter system. Meanwhile, the high voltage which is more suitable for the application can be obtained. Compared with normal charging method with parallel connected current limiting detention and charging method with dynamic irradian mode, constant load mode and constant voltage charging mode, the control scheme is proposed to shorten the charging time and increase the use of power generated from the PV array. From the simulation results and analysis conducted to determine the performance of the system in state transient and steady-state by using simulation software Matlab / Simulink. Response simulation results demonstrate the suitability of the proposed concept.

  10. Study on novel functional materials carboxymethyl cellulose lithium (CMC-Li) improve high-performance lithium-ion battery.

    Science.gov (United States)

    Qiu, Lei; Shao, Ziqiang; Xiang, Pan; Wang, Daxiong; Zhou, Zhenwen; Wang, Feijun; Wang, Wenjun; Wang, Jianquan

    2014-09-22

    Novel cellulose derivative CMC-Li was synthesized by cotton as raw material. The mechanism of the CMC-Li modified electrode materials by electrospinning was reported. CMC-Li/lithium iron phosphate (LiFePO4, LFP) composite fiber coated with LFP and CMC-Li nanofibers was successfully obtained by electrospinning. Then, CMC-Li/LFP nano-composite fiber was carbonized under nitrogen at a high temperature formed CNF/LFP/Li (CLL) composite nanofibers as cathode material. It can increase the contents of Li+, and improving the diffusion efficiency and specific capacity. The battery with CLL as cathode material retained close to 100% of initial reversible capacity after 200 cycles at 168 mAh g(-1), which was nearly the theoretical specific capacity of LFP. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and scanning electron microscope (SEM) were characterizing material performance. The batteries have good electrochemical property, outstanding pollution-free, excellent stability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Enhanced electrochemical performance of sandwich-structured polyaniline-wrapped silicon oxide/carbon nanotubes for lithium-ion batteries

    Science.gov (United States)

    Liu, Hui; Zou, Yongjin; Huang, Liyan; Yin, Hao; Xi, Chengqiao; Chen, Xin; Shentu, Hongwei; Li, Chao; Zhang, Jingjing; Lv, ChunJu; Fan, Meiqiang

    2018-06-01

    Sandwich-structured carbon nanotubes, silicon oxide, and polyaniline (hereafter denoted as CNTs/SiOx/PANI) were prepared by combining a sol-gel method, magnesiothermic reduction at 250 °C, and chemical oxidative polymerization. The CNTs, SiOx and PANI in the composite was 16 wt%, 51 wt% and 33 wt%, respectively. The CNTs/SiOx/PANI electrodes exhibited excellent cycle and high-rate performance as anodes in Li-ion batteries, including charge/discharge capacities of 1156/1178 mAh g-1 after 60 cycles at 0.2 A g-1 current density and 728/725 mAh g-1 at 8 A g-1 current density. The improvement was due to the synergy between CNTs and PANI. The SiOx scattered on the CNTs core and coated by PANI improved its conductivity and accommodated the volume change during repeated lithiation/delithiation cycles. This simple synthesis provided a scalable route for the large-scale production of CNTs/SiOx/PANI nanostructures, with various applications such as in Li-ion batteries.

  12. High performance screen-printed electrodes prepared by a green solvent approach for lithium-ion batteries

    Science.gov (United States)

    Gören, A.; Mendes, J.; Rodrigues, H. M.; Sousa, R. E.; Oliveira, J.; Hilliou, L.; Costa, C. M.; Silva, M. M.; Lanceros-Méndez, S.

    2016-12-01

    New inks based on lithium iron phosphate and graphite for cathode and anode, respectively, were developed for printable lithium-ion batteries using the "green solvent" N,N‧-dimethylpropyleneurea (DMPU) and poly(vinylidene fluoride), PVDF, as a binder. The results were compared with the ones from inks developed with the conventionally used solvent N-methyl-2-pyrrolidone, NMP. The rheological properties of the PVDF/DMPU binder solution shows a more pronounced shear thinning behavior than the PVDF/NMP solution. Cathode inks prepared with 2.25 mL and 2.50 mL of DMPU for 1 g of electrode mass show an apparent viscosity of 3 Pa s and 2 Pa s for a shear rate of 100 s-1, respectively, being therefore processable by screen-printing or doctor blade techniques. The electrodes prepared with DMPU and processed by screen-printing show a capacity of 52 mAh g-1 at 2C for the cathode and 349 mAh g-1 at C/5 for the anode, after 45 charge-discharge cycles. The electrochemical performance of both electrodes was evaluated in a full-cell and after 9 cycles, the discharge capacity value is 81 mAh g-1, showing a discharge capacity retention of 64%. The new inks presented in this work are thus suitable for the development of printed batteries and represent a step forward towards more environmental friendly processes.

  13. A Facile Bottom-Up Approach to Construct Hybrid Flexible Cathode Scaffold for High-Performance Lithium-Sulfur Batteries.

    Science.gov (United States)

    Ghosh, Arnab; Manjunatha, Revanasiddappa; Kumar, Rajat; Mitra, Sagar

    2016-12-14

    Lithium-sulfur batteries mostly suffer from the low utilization of sulfur, poor cycle life, and low rate performances. The prime factors that affect the performance are enormous volume change of the electrode, soluble intermediate product formation, poor electronic and ionic conductivity of S, and end discharge products (i.e., Li 2 S 2 and Li 2 S). The attractive way to mitigate these challenges underlying in the fabrication of a sulfur nanocomposite electrode consisting of different nanoparticles with distinct properties of lithium storage capability, mechanical reinforcement, and ionic as well as electronic conductivity leading to a mechanically robust and mixed conductive (ionic and electronic conductive) sulfur electrode. Herein, we report a novel bottom-up approach to synthesize a unique freestanding, flexible cathode scaffold made of porous reduced graphene oxide, nanosized sulfur, and Mn 3 O 4 nanoparticles, and all are three-dimensionally interconnected to each other by hybrid polyaniline/sodium alginate (PANI-SA) matrix to serve individual purposes. A capacity of 1098 mAh g -1 is achieved against lithium after 200 cycles at a current rate of 2 A g -1 with 97.6% of initial capacity at a same current rate, suggesting the extreme stability and cycling performance of such electrode. Interestingly, with the higher current density of 5 A g -1 , the composite electrode exhibited an initial capacity of 1015 mA h g -1 and retained 71% of the original capacity after 500 cycles. The in situ Raman study confirms the polysulfide absorption capability of Mn 3 O 4 . This work provides a new strategy to design a mechanically robust, mixed conductive nanocomposite electrode for high-performance lithium-sulfur batteries and a strategy that can be used to develop flexible large power storage devices.

  14. Cluster size matters: Size-driven performance of subnanometer clusters in catalysis, electrocatalysis and Li-air batteries

    Science.gov (United States)

    Vajda, Stefan

    2015-03-01

    This paper discusses the strongly size-dependent performance of subnanometer cluster based catalysts in 1) heterogeneous catalysis, 2) electrocatalysis and 3) Li-air batteries. The experimental studies are based on I. fabrication of ultrasmall clusters with atomic precision control of particle size and their deposition on oxide and carbon based supports; II. test of performance, III. in situand ex situ X-ray characterization of cluster size, shape and oxidation state; and IV.electron microscopies. Heterogeneous catalysis. The pronounced effect of cluster size and support on the performance of the catalyst (catalyst activity and the yield of Cn products) will be illustrated on the example of nickel and cobalt clusters in Fischer-Tropsch reaction. Electrocatalysis. The study of the oxygen evolution reaction (OER) on size-selected palladium clusters supported on ultrananocrystalline diamond show pronounced size effects. While Pd4 clusters show no reaction, Pd6 and Pd17 clusters are among the most active catalysts known (in in terms of turnover rate per Pd atom). The system (soft-landed Pd4, Pd6, or Pd17 clusters on an UNCD Si coated electrode) shows stable electrochemical potentials over several cycles, and the characterization of the electrodes show no evidence for evolution or dissolution of either the support Theoretical calculations suggest that this striking difference may be a demonstration that bridging Pd-Pd sites, which are only present in three-dimensional clusters, are active for the oxygen evolution reaction in Pd6O6. Li-air batteries. The studies show that sub-nm silver clusters have dramatic size-dependent effect on the lowering of the overpotential, charge capacity, morphology of the discharge products, as well as on the morphology of the nm size building blocks of the discharge products. The results suggest that by precise control of the active surface sites on the cathode, the performance of Li-air cells can be significantly improved

  15. Performance Enhancement of a Sulfur/Carbon Cathode by Polydopamine as an Efficient Shell for High-Performance Lithium-Sulfur Batteries.

    Science.gov (United States)

    Zhang, Xuqing; Xie, Dong; Zhong, Yu; Wang, Donghuang; Wu, Jianbo; Wang, Xiuli; Xia, Xinhui; Gu, Changdong; Tu, Jiangping

    2017-08-04

    Lithium-sulfur batteries (LSBs) are considered to be among the most promising next-generation high-energy batteries. It is a consensus that improving the conductivity of sulfur cathodes and impeding the dissolution of lithium polysulfides are two key accesses to high-performance LSBs. Herein we report a sulfur/carbon black (S/C) cathode modified by self-polymerized polydopamine (pDA) with the assistance of polymerization treatment. The pDA acts as a novel and effective shell on the S/C cathode to stop the shuttle effect of polysulfides. By the synergistic effect of enhanced conductivity and multiple blocking effect for polysulfides, the S/C@pDA electrode exhibits improved electrochemical performances including large specific capacity (1135 mAh g -1 at 0.2 C), high rate capability (533 mAh g -1 at 5 C) and long cyclic life (965 mAh g -1 after 200 cycles). Our smart design strategy may promote the development of high-performance LSBs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A Desalination Battery

    KAUST Repository

    Pasta, Mauro; Wessells, Colin D.; Cui, Yi; La Mantia, Fabio

    2012-01-01

    Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na 2-xMn 5O 10 nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l -1 for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (∼ 0.2 Wh l -1), the most efficient technique presently available. © 2012 American Chemical Society.

  17. A desalination battery.

    Science.gov (United States)

    Pasta, Mauro; Wessells, Colin D; Cui, Yi; La Mantia, Fabio

    2012-02-08

    Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na(2-x)Mn(5)O(10) nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l(-1) for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (~ 0.2 Wh l(-1)), the most efficient technique presently available. © 2012 American Chemical Society

  18. A Desalination Battery

    KAUST Repository

    Pasta, Mauro

    2012-02-08

    Water desalination is an important approach to provide fresh water around the world, although its high energy consumption, and thus high cost, call for new, efficient technology. Here, we demonstrate the novel concept of a "desalination battery", which operates by performing cycles in reverse on our previously reported mixing entropy battery. Rather than generating electricity from salinity differences, as in mixing entropy batteries, desalination batteries use an electrical energy input to extract sodium and chloride ions from seawater and to generate fresh water. The desalination battery is comprised by a Na 2-xMn 5O 10 nanorod positive electrode and Ag/AgCl negative electrode. Here, we demonstrate an energy consumption of 0.29 Wh l -1 for the removal of 25% salt using this novel desalination battery, which is promising when compared to reverse osmosis (∼ 0.2 Wh l -1), the most efficient technique presently available. © 2012 American Chemical Society.

  19. The effect of external dummy transmitters on oxygen consumption and performance of swimming Atlantic cod

    DEFF Research Database (Denmark)

    Steinhausen, M.F.; Andersen, Niels Gerner; Steffensen, J.F.

    2006-01-01

    Decreased critical swimming speed and increased oxygen consumption (Mo-2) was found for externally tagged Atlantic cod Gadus morhua swimming at a high speed of 0 center dot 9 body length (total length, L-Gamma) s(-1). No difference was found in the standard metabolic rate, indicating...... that the higher Mo-2 for tagged cod was due to drag force rather than increased costs to keep buoyancy. (c) 2006 The Authors Journal compilation (c) 2006 The Fisheries Society of the British Isles....

  20. Development of nickel hydrogen battery expert system

    Science.gov (United States)

    Shiva, Sajjan G.

    1990-01-01

    The Hubble Telescope Battery Testbed employs the nickel-cadmium battery expert system (NICBES-2) which supports the evaluation of performances of Hubble Telescope spacecraft batteries and provides alarm diagnosis and action advice. NICBES-2 also provides a reasoning system along with a battery domain knowledge base to achieve this battery health management function. An effort to modify NICBES-2 to accommodate nickel-hydrogen battery environment in testbed is described.

  1. A comprehensive model for diagnosing the causes of individual medical performance problems: skills, knowledge, internal, past and external factors (SKIPE).

    Science.gov (United States)

    Norfolk, Tim; Siriwardena, A Niroshan

    2013-01-01

    This discussion paper describes a new and comprehensive model for diagnosing the causes of individual medical performance problems: SKIPE (skills, knowledge, internal, past and external factors). This builds on a previous paper describing a unifying theory of clinical practice, the RDM-p model, which captures the primary skill sets required for effective medical performance (relationship, diagnostics and management), and the professionalism that needs to underpin them. The SKIPE model is currently being used, in conjunction with the RDM-p model, for the in-depth assessment and management of doctors whose performance is a cause for concern.

  2. General performance characteristics and parametric optimum criteria of a nano-thermoelectric refrigerator with an external magnetic field

    International Nuclear Information System (INIS)

    Wang Hao; Wu Guoxing; Xie Jian

    2012-01-01

    In the paper, we describe a single-level quantum dot with an external magnetic field that works as a nano-thermoelectric refrigerator. Based on the model, the expressions for the cooling rate (R), the power input (P) and the coefficient of performance (ε) are derived. The effects of the magnetic field strength and the level energy on the performance of the refrigerator are revealed. The optimal performance characteristics of the refrigerator are analyzed by numerical calculation. Furthermore, the practical operating regions of the cycle are determined.

  3. CoFe2O4/carbon nanotube aerogels as high performance anodes for lithium ion batteries

    Directory of Open Access Journals (Sweden)

    Xin Sun

    2017-04-01

    Full Text Available High-performance lithium ion batteries (LIBs require electrode material to have an ideal electrode construction which provides fast ion transport, short solid-state ion diffusion, large surface area, and high electric conductivity. Herein, highly porous three-dimensional (3D aerogels composed of cobalt ferrite (CoFe2O4, CFO nanoparticles (NPs and carbon nanotubes (CNTs are prepared using sustainable alginate as the precursor. The key feature of this work is that by using the characteristic egg-box structure of the alginate, metal cations such as Co2+ and Fe3+ can be easily chelated via an ion-exchange process, thus binary CFO are expected to be prepared. In the hybrid aerogels, CFO NPs interconnected by the CNTs are embedded in carbon aerogel matrix, forming the 3D network which can provide high surface area, buffer the volume expansion and offer efficient ion and electron transport pathways for achieving high performance LIBs. The as-prepared hybrid aerogels with the optimum CNT content (20 wt% delivers excellent electrochemical properties, i.e., reversible capacity of 1033 mAh g−1 at 0.1 A g−1 and a high specific capacity of 874 mAh g−1 after 160 cycles at 1 A g−1. This work provides a facile and low cost route to fabricate high performance anodes for LIBs. Keywords: Alginate, Aerogels, Cobalt ferrite, Anode, Lithium-ion battery

  4. MoS{sub 2}/cotton-derived carbon fibers with enhanced cyclic performance for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Yang, Yan [School of Electrical Engineering, Southwest Jiaotong University, Chengdu, 610031 (China); Liu, Jiangwen; Ouyang, Liuzhang; Liu, Jun; Hu, Renzong [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Yang, Lichun, E-mail: mslcyang@scut.edu.cn [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China); Zhu, Min [School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou, 510641 (China)

    2017-08-15

    Highlights: • MoS{sub 2} nanosheets vertically grow on cotton-derived carbon microfibers. • The carbon fibers facilitate charge transfer and structure stabilization. • The MoS{sub 2}/CDCFs exhibit enhanced cyclic performance for reversible Na{sup +} storage. - Abstract: Carbon fibers derived from bio-template are low cost and environmental benign, therefore have attracted much attention in energy storage materials. In this work, we successfully fabricated MoS{sub 2}/cotton-derived carbon fibers (MoS{sub 2}/CDCFs) via hydrothermal route followed by carbonization process. In the composite of MoS{sub 2}/CDCFs, MoS{sub 2} nanosheets vertically grow on the carbon fibers which offer fast ways for electron transfer and at the same time act as robust support to buffer the volume changes of MoS{sub 2} nanosheets during discharge/charge cycles. As anode materials for sodium-ion batteries, MoS{sub 2}/CDCFs exhibit good rate performance and markedly enhanced cyclic stability due to the conductive support of CDCFs. At a current density of 0.1 A g{sup −1}, the MoS{sub 2}/CDCFs-1 shows an initial reversible capacity of 504.9 mAh g{sup −1}, and maintains 444.5 mAh g{sup −1} after 50 cycles. Even when the current density increases to 0.5 A g{sup −1}, it maintains 323.1 mAh g{sup −1} after 150 cycles, which is much higher than the capacity retention of 149.6 mAh g{sup −1} for the bare MoS{sub 2} nanosheets. The improved electrochemical performance verifies the effective strategy of using cotton as carbon source to construct hierarchical composites for sodium-ion batteries.

  5. The design paradox: the contribution of in-house and external design activities on product market performance

    OpenAIRE

    Czarnitzki, Dirk; Thorwarth, Susanne

    2009-01-01

    This paper explores the contribution of design activities on product market performance of Belgian companies. While there is mounting evidence that design can be seen as a strategic tool to successfully spur sales of new product developments at the firm level, the topic of design innovation has not been linked to the open innovation concept yet. In this paper we empirically test whether design activities conducted in-house differ in their contribution to new product sales from externally acqu...

  6. Prediction And Performance Assessments of External Horizontal Global Illuminance of Measured Data from Port-Harcourt, Nigeria

    International Nuclear Information System (INIS)

    Akingbade, F.O.A.

    2002-01-01

    This paper reports the measurements and analysis of external horizontal global illuminance for Port-Harcourt, Nigeria. A set of empirical expressions were derived from seasonal and yearly variations of horizontal global illuminance against solar altitude. The model derived from the study performed better compared with two other models proposed for the area from other studies conducted elsewhere. The results presented here serves to develop the base for reliable localized day lighting data to be used in building designs in the area

  7. Flexibility of internal and external glenohumeral rotation of junior female tennis players and its correlation with performance ranking.

    Science.gov (United States)

    Chiang, Ching-Cheng; Hsu, Chih-Chia; Chiang, Jinn-Yen; Chang, Weng-Cheng; Tsai, Jong-Chang

    2016-12-01

    [Purpose] The purpose of this study was to compare the internal and external rotation of the dominant and nondominant shoulders of adolescent female tennis players. The correlation between the shoulder rotation range of motion and the player's ranking was also analyzed. [Subjects and Methods] Twenty-one female junior tennis players who were 13 to 18 years old participated in this study. A standard goniometer was used to measure the internal and external rotation of both glenohumeral joints. The difference in internal and external rotation was calculated as the glenohumeral rotation deficit. The year-end ranking of each player was obtained from the Chinese Taipei Tennis Association. [Results] The internal rotation of the dominant shoulder was significantly smaller than that of the nondominant shoulder. Moreover, player ranking was significantly and negatively correlated with the internal rotation range of motion of both shoulders. On the other hand, the correlations of the internal and external rotation ranges of motion with the age, height, and weight were not significant. [Conclusion] The flexibility of the glenohumeral internal rotation is smaller in the dominant shoulder than of the nondominant shoulder in these junior female tennis players. Flexibility of the glenohumeral internal rotation may be a factor affecting performance in junior female tennis players.

  8. Electrochemical accumulators batteries; Accumulateurs electrochimiques batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ansart, F; Castillo, S; Laberty- Robert, C; Pellizon-Birelli, M [Universite Paul Sabatier, Lab. de Chimie des Materiaux Inorganiques et Energetiques, CIRIMAT, UMR CNRS 5085, 31 - Toulouse (France); and others

    2000-07-01

    It is necessary to storage the electric power in batteries to join the production and the utilization. In this domain progresses are done every days in the technics and also in the available materials. These technical days present the state of the art in this domain. Many papers were presented during these two days giving the research programs and recent results on the following subjects: the lithium batteries, the electrolytes performances and behaviour, lead accumulators, economic analysis of the electrochemical storage market, the batteries applied to the transportation sector and the telephones. (A.L.B.)

  9. The performance of passive flow monitors and phosphate accumulating passive samplers when exposed to pulses in external water flow rate and/or external phosphate concentrations

    International Nuclear Information System (INIS)

    O'Brien, Dominique; Hawker, Darryl; Shaw, Melanie; Mueller, Jochen F.

    2011-01-01

    Passive samplers are typically calibrated under constant flow and concentration conditions. This study assessed whether concentration and/or flow pulses could be integrated using a phosphate passive sampler (P-sampler). Assessment involved three 21-day experiments featuring a pulse in flow rate, a pulse of filterable reactive phosphate (FRP) concentration and a simultaneous concentration and flow pulse. FRP concentrations were also determined by parallel grab sampling and the P-sampler calibrated with passive flow monitors (PFMs) and direct measurement of flow rates. The mass lost from the PFM over the deployment periods predicted water velocity to within 5.1, 0.48 and 7.1% when exposed to a flow rate pulse (7.5-50 cm s -1 ), concentration pulse (5-100 μg P L -1 ), or both simultaneously. For the P-sampler, good agreement was observed between the grab and passive measurements of FRP concentration when exposed to a pulse in flow (6% overestimation) or concentration (2% underestimation). - Highlights: → We assess the performance of the passive flow monitor and a phosphate passive sampler when exposed to changing environmental conditions. → The PFM responded quickly and accurately to a pulse in flow rate but showed little response to an external FRP pulse. → The ability of the sampler to provide an integrated measure of the average phosphate concentrations has been demonstrated. → The results presented demonstrate under which conditions the greatest accuracy is achieved when employing passive samplers. - The performance of an integrative phosphate passive sampler has been assessed when exposed to pulses in flow rate and concentration, both individually and simultaneously.

  10. Mesoporous Silicon Sponge as an Anti-Pulverization Structure for High-Performance Lithium-ion Battery Anodes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaolin; Gu, Meng; Hu, Shenyang Y.; Kennard, Rhiannon; Yan, Pengfei; Chen, Xilin; Wang, Chong M.; Sailor, Michael J.; Zhang, Jiguang; Liu, Jun

    2014-07-08

    Nanostructured silicon is a promising anode material for high performance lithium-ion batteries, yet scalable synthesis of such materials, and retaining good cycling stability in high loading electrode remain significant challenges. Here, we combine in-situ transmission electron microscopy and continuum media mechanical calculations to demonstrate that large (>20 micron) mesoporous silicon sponge (MSS) prepared by the scalable anodization method can eliminate the pulverization of the conventional bulk silicon and limit particle volume expansion at full lithiation to ~30% instead of ~300% as observed in bulk silicon particles. The MSS can deliver a capacity of ~750 mAh/g based on the total electrode weight with >80% capacity retention over 1000 cycles. The first-cycle irreversible capacity loss of pre-lithiated MSS based anode is only <5%. The insight obtained from MSS also provides guidance for the design of other materials that may experience large volume variation during operations.

  11. Synthesis and electrochemical performance of hierarchical Sb2S3 nanorod-bundles for lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    XIAOZHONG ZHOU

    2014-05-01

    Full Text Available Uniform hierarchical Sb2S3 nanorod-bundles were synthesised successfully by L-cysteine hydrochloride-assisted solvothermal treatment, and were then characterised by X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy, respectively. The electrochemical performance of the synthesised Sb2S3 nanorod-bundles was investigated by cyclic voltammetry and galvanostatic charge−discharge technique, respectively. This material was found to exhibit a high initial charge specific capacity of 803 mA h g-1 at a rate of 100 mA g-1, a good cyclability of 614 mA h g-1 at a rate of 100 mA g-1 after 30 cycles, and a good rate capability of 400 mA h g-1 at a rate of 500 mA g-1 when evaluated as an electrode candidate material for lithium-ion batteries.

  12. Nanostructure Sn-Co-C composite lithium ion battery electrode with unique stability and high electrochemical performance

    International Nuclear Information System (INIS)

    Li Mengyuan; Liu Chunling; Shi Meirong; Dong Wensheng

    2011-01-01

    Nanostructure Sn-Co-C composites with different compositions are synthesized by a simple solution polymerization using inexpensive raw materials followed by pyrolysis in nitrogen atmosphere. The nanostructure Sn-Co-C composites are characterized using various analytic techniques. The results show that the electrochemical performances of the composites are strongly dependent on their structure and composition. Among these composites the Sn-Co-C-1 with a weight composition of Sn 0.31 Co 0.09 C 0.6 exhibits high reversible capacity and excellent cycleability when used as an anode for rechargeable lithium ion batteries. This composite is composed of SnCo 2 , SnCo, Sn and amorphous carbon, and the nanoparticles of SnCo 2 , SnCo and Sn are uniformly dispersed into the amorphous carbon matrix, the average diameter of these metal nanoparticles is 8.44 nm.

  13. Efficient preparation of highly hydrogenated graphene and its application as a high-performance anode material for lithium ion batteries

    Science.gov (United States)

    Chen, Wufeng; Zhu, Zhiye; Li, Sirong; Chen, Chunhua; Yan, Lifeng

    2012-03-01

    A novel method has been developed to prepare hydrogenated graphene (HG) via a direct synchronized reduction and hydrogenation of graphene oxide (GO) in an aqueous suspension under 60Co gamma ray irradiation at room temperature. GO can be reduced by the aqueous electrons (eaq-) while the hydrogenation takes place due to the hydrogen radicals formed in situ under irradiation. The maximum hydrogen content of the as-prepared highly hydrogenated graphene (HHG) is found to be 5.27 wt% with H/C = 0.76. The yield of the target product is on the gram scale. The as-prepared HHG also shows high performance as an anode material for lithium ion batteries.

  14. Manganese oxide electrode with excellent electrochemical performance for sodium ion batteries by pre-intercalation of K and Na ions.

    Science.gov (United States)

    Feng, Mengya; Du, Qinghua; Su, Li; Zhang, Guowei; Wang, Guiling; Ma, Zhipeng; Gao, Weimin; Qin, Xiujuan; Shao, Guangjie

    2017-05-22

    Materials with a layered structure have attracted tremendous attention because of their unique properties. The ultrathin nanosheet structure can result in extremely rapid intercalation/de-intercalation of Na ions in the charge-discharge progress. Herein, we report a manganese oxide with pre-intercalated K and Na ions and having flower-like ultrathin layered structure, which was synthesized by a facile but efficient hydrothermal method under mild condition. The pre-intercalation of Na and K ions facilitates the access of electrolyte ions and shortens the ion diffusion pathways. The layered manganese oxide shows ultrahigh specific capacity when it is used as cathode material for sodium-ion batteries. It also exhibits excellent stability and reversibility. It was found that the amount of intercalated Na ions is approximately 71% of the total charge. The prominent electrochemical performance of the manganese oxide demonstrates the importance of design and synthesis of pre-intercalated ultrathin layered materials.

  15. The use of polybenzimidazole membranes in vanadium redox flow batteries leading to increased coulombic efficiency and cycling performance

    International Nuclear Information System (INIS)

    Zhou, X.L.; Zhao, T.S.; An, L.; Wei, L.; Zhang, C.

    2015-01-01

    An issue with conventional vanadium redox flow batteries (VRFB) with Nafion membranes is the crossover of vanadium ions, resulting in low coulombic efficiency and rapid decay in capacity. In this work, a VRFB with a polybenzimidazole (PBI) membrane is tested and compared with the Nafion system. Results show that the PBI-based VRFB exhibits a substantially higher coulombic efficiency of up to 99% at current densities ranging from 20 mA cm −2 to 80 mA cm −2 . More importantly, it is demonstrated that the PBI-based VRFB has a capacity decay rate of as low as 0.3% per cycle, which is four times lower than that of the Nafion system (1.3% per cycle). The improved coulombic efficiency and cycling performance are attributed to the low crossover of vanadium ions through the PBI membrane

  16. Effects of low-pressure nitrogen plasma treatment on the surface properties and electrochemical performance of the polyethylene separator used lithium-ion batteries

    Science.gov (United States)

    Li, Chun; Li, Hsiao-Ling; Li, Chi-Heng; Liu, Yu-Shuan; Sung, Yu-Ching; Huang, Chun

    2018-01-01

    In this paper, we describe the surface transition of the polyethylene (PE) separator used in lithium-ion batteries treated by low-pressure nitrogen plasma discharge. The nitrogen-plasma-treated PE separator was characterized by contact angle measurement, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The electrochemical performance of the lithium ion batteries fabricated with the nitrogen-plasma-treated separator was also evaluated. Results showed that polar functionalization groups were induced on the PE surface by the nitrogen plasma discharge, causing the surface to become hydrophilic. The increases in surface wettability and surface free energy result in electrolyte retention improvement. Moreover, the nitrogen plasma-treated PE separator leads to superior performance in lithium-ion battery assembly.

  17. Untreated Natural Graphite as a Graphene Source for High-Performance Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    María Simón

    2018-03-01

    Full Text Available Graphene nanosheets (GNS are synthesized from untreated natural graphite (NG for use as electroactive materials in Li-ion batteries (LIBs, which avoids the pollution-generating steps of purifying graphite. Through a modified Hummer method and subsequent thermal exfoliation, graphitic oxide and graphene were synthesized and characterized structurally, morphologically and chemically. Untreated natural graphite samples contain 45–50% carbon by weight; the rest is composed of different elements such as aluminium, calcium, iron, silicon and oxygen, which are present as calcium carbonate and silicates of aluminium and iron. Our results confirm that in the GO and GNS synthesized, calcium is removed due to oxidation, though other impurities are maintained because they are not affected by the synthesis. Despite the remaining mineral phases, the energy storage capacity of GNS electrodes is very promising. In addition, an electrochemical comparison between GNS and NG demonstrated that the specific capacity in GNS is higher during the whole cycling process, 770 mA·g−1 at 100th cycle, which is twice that of graphite.

  18. Effects of Electrospun Carbon Nanofibers’ Interlayers on High-Performance Lithium–Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    Tianji Gao

    2017-03-01

    Full Text Available Two different interlayers were introduced in lithium–sulfur batteries to improve the cycling stability with sulfur loading as high as 80% of total mass of cathode. Melamine was recommended as a nitrogen-rich (N-rich amine component to synthesize a modified polyacrylic acid (MPAA. The electrospun MPAA was carbonized into N-rich carbon nanofibers, which were used as cathode interlayers, while carbon nanofibers from PAA without melamine was used as an anode interlayer. At the rate of 0.1 C, the initial discharge capacity with two interlayers was 983 mAh g−1, and faded down to 651 mAh g−1 after 100 cycles with the coulombic efficiency of 95.4%. At the rate of 1 C, the discharge capacity was kept to 380 mAh g−1 after 600 cycles with a coulombic efficiency of 98.8%. It apparently demonstrated that the cathode interlayer is extremely effective at shutting down the migration of polysulfide ions. The anode interlayer induced the lithium ions to form uniform lithium metal deposits confined on the fiber surface and in the bulk to strengthen the cycling stability of the lithium metal anode.

  19. Design and Performance Evaluation of a Wind-Hydrogen Autonomous System Associated to a Rechargeable Battery

    Science.gov (United States)

    Yu, Guang; Okada, Nobuhiro

    A sailing-type wind farm which can move freely on oceans has been proposed in Japan since 2003. In this system the wind power is turned into hydrogen using an electrolyzer and then transported to end users. Since the sailing-type wind farm is a stand-alone system and the wind is intermittent, the efficiency of hydrogen production is quite low when the electrolyzer power is below a certain value. Additionally, the electrolyzer is inevitably shutdown frequently for lack of power. The frequent electrolyzer start-up actions can also decrease the efficiency of hydrogen production and shorten the electrolyzer's lifetime. In this paper, we applied a rechargeable battery and a proper control algorithm to the system to guarantee the hydrogen production efficiency and reduce the electrolyzer's start-up times. A simulation model of the whole system was developed and wind data was used to test the validity of the method. The simulation results showed that the proposed method can effectively improve the hydrogen productivity and reduce the start-up times.

  20. High-performance sodium-organic battery by realizing four-sodium storage in disodium rhodizonate

    Science.gov (United States)

    Lee, Minah; Hong, Jihyun; Lopez, Jeffrey; Sun, Yongming; Feng, Dawei; Lim, Kipil; Chueh, William C.; Toney, Michael F.; Cui, Yi; Bao, Zhenan

    2017-11-01

    Sodium-ion batteries (SIBs) for grid-scale applications need active materials that combine a high energy density with sustainability. Given the high theoretical specific capacity 501 mAh g-1, and Earth abundance of disodium rhodizonate (Na2C6O6), it is one of the most promising cathodes for SIBs. However, substantially lower reversible capacities have been obtained compared with the theoretical value and the understanding of this discrepancy has been limited. Here, we reveal that irreversible phase transformation of Na2C6O6 during cycling is the origin of the deteriorating redox activity of Na2C6O6. The active-particle size and electrolyte conditions were identified as key factors to decrease the activation barrier of the phase transformation during desodiation. On the basis of this understanding, we achieved four-sodium storage in a Na2C6O6 electrode with a reversible capacity of 484 mAh g-1, an energy density of 726 Wh kg-1cathode, an energy efficiency above 87% and a good cycle retention.