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Sample records for nickel-rich oxides lini1-xmxo2

  1. Synthesis, electrochemical investigation and structural analysis of doped Li[Ni0.6Mn0.2Co0.2-xMx]O2 (x = 0, 0.05; M = Al, Fe, Sn) cathode materials

    Science.gov (United States)

    Eilers-Rethwisch, Matthias; Winter, Martin; Schappacher, Falko Mark

    2018-05-01

    Layered Ni-rich Li[Ni0.6Mn0.2Co0.2-xMx]O2 cathode materials (x = 0, 0.05; M = Al, Fe, Sn) are synthesized via a co-precipitation synthesis route and the effect of dopants on the structure and electrochemical performance is investigated. All synthesized materials show a well-defined layered structure of the hexagonal α-NaFeO2 phase investigated by X-ray diffraction (XRD). Undoped LiNi0.6Mn0.2Co0.2O2 exhibits a discharge capacity of 170 mAh g-1 in Li-metal 2032 coin-type cells. Doped materials reach lower capacities between 145 mAh g-1 for Al and 160 mAh g-1 for Sn. However, all doped materials prolong the cycle life by up to 20%. Changes of the lattice parameter before and after delithiation yield information about structural stability. A smaller repulsion of the transition metal layer during delithiation in the Sn-doped material leads to a smaller expansion of the unit cell, which results in enhanced structural stability of the material. The improved structural stability of Sn-doped NMC cathode active material is proven by thermal investigations with the help of Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA).

  2. Design of Nickel-Based Cation-Disordered Rock-Salt Oxides: The Effect of Transition Metal (M = V, Ti, Zr) Substitution in LiNi0.5M0.5O2 Binary Systems.

    Science.gov (United States)

    Cambaz, Musa Ali; Vinayan, Bhaghavathi P; Euchner, Holger; Johnsen, Rune E; Guda, Alexander A; Mazilkin, Andrey; Rusalev, Yury V; Trigub, Alexander L; Gross, Axel; Fichtner, Maximilian

    2018-06-20

    Cation-disordered oxides have been ignored as positive electrode material for a long time due to structurally limited lithium insertion/extraction capabilities. In this work, a case study is carried out on nickel-based cation-disordered Fm3 ̅m LiNi 0.5 M 0.5 O 2 positive electrode materials. The present investigation targets tailoring the electrochemical properties for nickel-based cation-disordered rock-salt by electronic considerations. The compositional space for binary LiM +3 O 2 with metals active for +3/+4 redox couples is extended to ternary oxides with LiA 0.5 B 0.5 O 2 with A = Ni 2+ and B = Ti 4+ , Zr 4+ , and V +4 to assess the impact of the different transition metals in the isostructural oxides. The direct synthesis of various new unknown ternary nickel-based Fm3̅ m cation-disordered rock-salt positive electrode materials is presented with a particular focus on the LiNi 0.5 V 0.5 O 2 system. This positive electrode material for Li-ion batteries displays an average voltage of ∼2.55 V and a high discharge capacity of 264 mAhg -1 corresponding to 0.94 Li. For appropriate cutoff voltages, a long cycle life is achieved. The charge compensation mechanism is probed by XANES, confirming the reversible oxidation and reduction of V 4+ /V 5+ . The enhancement in the electrochemical performances within the presented compounds stresses the importance of mixed cation-disordered transition metal oxides with different electronic configuration.

  3. High-energy cathode material for long-life and safe lithium batteries

    Science.gov (United States)

    Sun, Yang-Kook; Myung, Seung-Taek; Park, Byung-Chun; Prakash, Jai; Belharouak, Ilias; Amine, Khalil

    2009-04-01

    Layered lithium nickel-rich oxides, Li[Ni1-xMx]O2 (M=metal), have attracted significant interest as the cathode material for rechargeable lithium batteries owing to their high capacity, excellent rate capability and low cost. However, their low thermal-abuse tolerance and poor cycle life, especially at elevated temperature, prohibit their use in practical batteries. Here, we report on a concentration-gradient cathode material for rechargeable lithium batteries based on a layered lithium nickel cobalt manganese oxide. In this material, each particle has a central bulk that is rich in Ni and a Mn-rich outer layer with decreasing Ni concentration and increasing Mn and Co concentrations as the surface is approached. The former provides high capacity, whereas the latter improves the thermal stability. A half cell using our concentration-gradient cathode material achieved a high capacity of 209mAhg-1 and retained 96% of this capacity after 50 charge-discharge cycles under an aggressive test profile (55∘C between 3.0 and 4.4V). Our concentration-gradient material also showed superior performance in thermal-abuse tests compared with the bulk composition Li[Ni0.8Co0.1Mn0.1]O2 used as reference. These results suggest that our cathode material could enable production of batteries that meet the demanding performance and safety requirements of plug-in hybrid electric vehicles.

  4. Influence of Temperature on the Performance of LiNi1/3Co1/3Mn1/3O2 Prepared by High-Temperature Ball-Milling Method

    Directory of Open Access Journals (Sweden)

    Ming Tian

    2018-01-01

    Full Text Available Aiming at the preparation of high electrochemical performance LiNi1/3Co1/3Mn1/3O2 cathode material for lithium-ion battery, LiNi1/3Co1/3Mn1/3O2 was prepared with lithium carbonate, nickel (II oxide, cobalt (II, III oxide, and manganese dioxide as raw materials by high-temperature ball-milling method. Influence of ball-milling temperature was investigated in this work. It was shown that the fine LiNi1/3Co1/3Mn1/3O2 powder with high electrochemical performance can be produced by the high-temperature ball-milling process, and the optimal ball-milling temperature obtained in the current study was 750°C. Its initial discharge capacity was 146.0 mAhg−1 at the rate of 0.1 C, and over 50 cycles its capacity retention rate was 90.2%.

  5. Tris(trimethylsilyl)phosphate as electrolyte additive for self-discharge suppression of layered nickel cobalt manganese oxide

    International Nuclear Information System (INIS)

    Liao, Xiaolin; Zheng, Xiongwen; Chen, Jiawei; Huang, Ziyu; Xu, Mengqing; Xing, Lidan; Liao, Youhao; Lu, Qilun; Li, Xiangfeng; Li, Weishan

    2016-01-01

    Highlights: • TMSP is effective for self-discharge suppression of the charged NCM under 4.5 V. • TMSP oxidizes preferentially forming protective cathode interface film on NCM. • The film suppresses electrolyte decomposition and prevents NCM destruction. - Abstract: Application of layered nickel cobalt manganese oxide as cathode under higher potential than conventional 4.2 V yields a significant improvement in energy density of lithium ion battery. However, the cathode fully charged under high potential suffers serious self-discharge, in which the interaction between the cathode and electrolyte proceeds without potential limitation. In this work, we use tris(trimethylsilyl)phosphate (TMSP) as an electrolyte additive to solve this problem. A representative layered nickel cobalt manganese oxide, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , is considered. The effect of TMSP on self-discharge behavior of LiNi 1/3 Co 1/3 Mn 1/3 O 2 is evaluated by physical and electrochemical methods. It is found that the self-discharge of charged LiNi 1/3 Co 1/3 Mn 1/3 O 2 can be suppressed significantly by using TMSP. TMSP is oxidized preferentially in comparison with the standard electrolyte during initial charging process forming a protective cathode interface film, which avoids the interaction between cathode and electrolyte at any potential and thus prevents electrolyte decomposition and protects LiNi 1/3 Co 1/3 Mn 1/3 O 2 from structure destruction.

  6. GITT studies on oxide cathode LiNi1/3Co1/3Mn1/3O2 synthesized ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... GITT studies on oxide cathode LiNi1/3Co1/3Mn1/3O2 synthesized by citric acid assisted high-energy ball milling ... The State Key Laboratory Base of Novel Functional Materials and Preparation Science; The Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, P. R. ...

  7. Dual functions of zirconium modification on improving the electrochemical performance of Ni-rich LiNi0.8Co0.1Mn0.1O2

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xing; Zhang, Kangjia; Wang, Mingshan; Liu, Yang; Qu, Meizhen; Zhao, Wengao; Zheng, Jianming

    2018-02-28

    Trace amount of Zirconium (Zr) has been adopted to modify the crystal structure and surface of the Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material. During cycling at 1.0C, the Zr-modified NCM811 shows an improved capacity retention of 92% after 100 cycles, higher than 75% for pristine NMC811. In addition, the Zr-modified NCM811 is capable of delivering a discharge capacity of 107 mAh g-1 at 10.0C rate, much higher than 28 mAh g-1 delivered by pristine material. These improved electrochemical performances are ascribed to the dual functions of Zr modification. On one hand, part of the Zr enters the crystal lattice, which is beneficial for reducing the Li/Ni cation mixing and enhancing the crystal stability of the cathode. On the other hand, the rest of the Zr forms a 1~2 nm thick coating layer on the surface of the NCM811 cathode, which effectively prevents the direct contact between NCM and the electrolyte, thus suppressing the detrimental interfacial reactions. Therefore, the Zr-modified LiNi0.8Co0.1Mn0.1O2 exhibited significantly enhanced cycling stability and charging/discharging rate capability in comparison with the untreated counterpart.

  8. In Situ Carbon Coated LiNi0.5Mn1.5O4 Cathode Material Prepared by Prepolymer of Melamine Formaldehyde Resin Assisted Method

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2016-01-01

    Full Text Available Carbon coated spinel LiNi0.5Mn1.5O4 were prepared by spray-drying using prepolymer of melamine formaldehyde resin (PMF as carbon source of carbon coating layer. The PMF carbon coated LiNi0.5Mn1.5O4 was characterized by XRD, SEM, and other electrochemical measurements. The as-prepared lithium nickel manganese oxide has the cubic face-centered spinel structure with a space group of Fd3m. It showed good electrochemical performance as a cathode material for lithium ion battery. After 100 discharge and charge cycles at 0.5 C rate, the specific discharge capacity of carbon coated LiNi0.5Mn1.5O4 was 130 mAh·g−1, and the corresponding capacity retention was 98.8%. The 100th cycle specific discharge capacity at 10 C rate of carbon coated LiNi0.5Mn1.5O4 was 105.4 mAh·g−1, and even the corresponding capacity retention was 95.2%.

  9. Improved high-voltage performance of LiNi1/3Co1/3Mn1/3O2 cathode with Tris(2,2,2-trifluoroethyl) phosphite as electrolyte additive

    International Nuclear Information System (INIS)

    Wang, Long; Ma, Yulin; Li, Qin; Cui, Yingzhi; Wang, Panpan; Cheng, Xinqun; Zuo, Pengjian; Du, Chunyu; Gao, Yunzhi

    2017-01-01

    Tris(2,2,2-trifluoroethyl) phosphite (TTFEP) is investigated as an electrolyte additive to improve the electrochemical performance of LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode at high operating voltage (4.6 V). Charge/discharge measurements demonstrate that TTFEP is effective to improve the cycling stability and rate capability of LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode. The capacity retention of LiNi 1/3 Co 1/3 Mn 1/3 O 2 /Li cell with 1% TTFEP-containing electrolyte reaches up to 85.4% after 100 cycles at 0.5C (1C = 160 mA g −1 ), while that of the cell with the baseline electrolyte (1 M LiPF 6 in EC/DMC electrolyte) only remains 74.2%. Moreover, the discharge capacity of the cathode with 1% TTFEP-containing electrolyte could maintain around 112.0 mAh g −1 at 4C. Based on the characterization of electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), a protective interphase film formed on the cathode surface can be found due to the preferential oxidation of TTFEP, which inhibits the electrolyte decomposition and mitigates the cathode structural destruction, leading to the improved electrochemical performance of LiNi 1/3 Co 1/3 Mn 1/3 O 2 cathode at high voltage.

  10. Synchrotron radiation-based 61Ni Mössbauer spectroscopic study of Li(Ni1/3Mn1/3Co1/3)O2 cathode materials of lithium ion rechargeable battery

    Science.gov (United States)

    Segi, Takashi; Masuda, Ryo; Kobayashi, Yasuhiro; Tsubota, Takayuki; Yoda, Yoshitaka; Seto, Makoto

    2016-12-01

    Layered rocksalt type oxides, such as Li(Ni1/3Mn1/3Co1/3)O2, are widely used as the cathode active materials of lithium-ion rechargeable batteries. Because the nickel ions are associated with the role of the charge compensation at discharge and charge, the 61Ni Mössbauer measurements at 6 K using synchrotron radiation were performed to reveal the role of Ni. The Ni ions of the active materials play two roles for the redox process between the charge and discharge states of lithium-ion batteries. Half of the total Ni ions change to the low-spin Ni3+ with Jahn-Teller distortion from the Ni2+ ions of the discharge state. The remainder exhibit low-spin state divalent Ni ions.

  11. GITT studies on oxide cathode LiNi1/3Co1/3Mn1/3O2 synthesized ...

    Indian Academy of Sciences (India)

    Li diffusion; LiNi1/3Co1/3Mn1/3O2; lithium ion batteries; layered structure. 1. Introduction ... The coin-type cell CR2012 consisting of a metallic- lithium foil anode ... and the polyvinylidenefluoride (PVDF) binder with a mass ratio of 4:1:1 in NMP ...

  12. Improving cyclic stability of lithium nickel manganese oxide cathode for high voltage lithium ion battery by modifying electrode/electrolyte interface with electrolyte additive

    International Nuclear Information System (INIS)

    Li, Bin; Wang, Yaqiong; Tu, Wenqiang; Wang, Zaisheng; Xu, Mengqing; Xing, Lidan; Li, Weishan

    2014-01-01

    Highlights: • Cyclic stability of LiNi 0.5 Mn 1.5 O 4 is improved significantly by using PES as additive. • A protective SEI is formed on LiNi 0.5 Mn 1.5 O 4 due to the preferential oxidation of PES. • The SEI suppresses electrolyte decomposition and structure destruction of LiNi 0.5 Mn 1.5 O 4 . - Abstract: We report a new approach to improve the cyclic stability of lithium nickel manganese oxide (LiNi 0.5 Mn 1.5 O 4 ) cathode, in which the cathode/electrolyte interface is modified by using prop-1-ene-1, 3-sultone (PES) as an electrolyte additive. The interfacial properties of LiNi 0.5 Mn 1.5 O 4 cathode in PES-containing electrolyte have been investigated by scanning electron spectroscopy (SEM), transmission electron microscopy (TEM), thermal gravimetry (TG), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammometry (CV), chronoamperometry (CA), and constant current charge/discharge test. It is found that the application of PES improves significantly the cyclic stability of LiNi 0.5 Mn 1.5 O 4 . After 400 cycles at 1C rate (1C=147 mA g −1 ), the capacity retention of LiNi 0.5 Mn 1.5 O 4 is 90% for the cell using 1.0 wt% PES, while only 49% for the cell without the additive. The characterizations from SEM, TEM, TG, XRD, and XPS confirm that the LiNi 0.5 Mn 1.5 O 4 /electrolyte interface is modified and a protective solid electrolyte interface film is formed on LiNi 0.5 Mn 1.5 O 4 particles, which prevents LiNi 0.5 Mn 1.5 O 4 from destruction and suppresses the electrolyte decomposition

  13. Towards deriving Ni-rich cathode and oxide-based anode materials from hydroxides by sharing a facile co-precipitation method.

    Science.gov (United States)

    Qiu, Haifa; Du, Tengfei; Wu, Junfeng; Wang, Yonglong; Liu, Jian; Ye, Shihai; Liu, Sheng

    2018-05-22

    Although intensive studies have been conducted on layered transition metal oxide(TMO)-based cathode materials and metal oxide-based anode materials for Li-ion batteries, their precursors generally follow different or even complex synthesis routes. To share one route for preparing precursors of the cathode and anode materials, herein, we demonstrate a facile co-precipitation method to fabricate Ni-rich hydroxide precursors of Ni0.8Co0.1Mn0.1(OH)2. Ni-rich layered oxide of LiNi0.8Co0.1Mn0.1O2 is obtained by lithiation of the precursor in air. An NiO-based anode material is prepared by calcining the precursor or multi-walled carbon nanotubes (MWCNTs) incorporated precursors. The pre-addition of ammonia solution can simplify the co-precipitation procedures and the use of an air atmosphere can also make the heat treatment facile. LiNi0.8Co0.1Mn0.1O2 as the cathode material delivers a reversible capacity of 194 mA h g-1 at 40 mA g-1 and a notable cycling retention of 88.8% after 100 cycles at 200 mA g-1. This noticeable performance of the cathode arises from a decent particle morphology and high crystallinity of the layered oxides. As the anode material, the MWCNTs-incorporated oxides deliver a much higher reversible capacity of 811.1 mA h g-1 after 200 cycles compared to the pristine oxides without MWCNTs. The improvement on electrochemical performance can be attributed to synergistic effects from MWCNTs incorporation, including reinforced electronic conductivity, rich meso-pores and an alleviated volume effect. This facile and sharing method may offer an integrated and economical approach for commercial production of Ni-rich electrode materials for Li-ion batteries.

  14. Enhancement of electrochemical performance of LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 by surface modification with MnO_2

    International Nuclear Information System (INIS)

    Guo, Xin; Cong, Li-Na; Zhao, Qin; Tai, Ling-Hua; Wu, Xing-Long; Zhang, Jing-Ping; Wang, Rong-Shun; Xie, Hai-Ming; Sun, Li-Qun

    2015-01-01

    LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 is successfully coated with MnO_2 by a chemical deposition method. The X-ray diffraction (XRD), scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) results demonstrate that MnO_2 forms a thin layer on the surface of LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 without destroying the crystal structure of the core material. Compared with pristine LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2, the MnO_2-coated sample shows enhanced electrochemical performance especially the rate capability. Even at a current density of 750 mA g"−"1, the discharge capacity of MnO_2-coated LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 is 155.15 mAh g"−"1, while that of the pristine electrode is only 132.84 mAh g"−"1 in the range of 2.5–4.5 V. The cyclic voltammetry (CV) and X-ray photoelectron spectroscopy (XPS) curves show that the MnO_2 coating layer reacts with Li"+ during cycling, which is responsible for the higher discharge capacity of MnO_2-coated LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2. Electrochemical impedance spectroscopy (EIS) results confirmed that the MnO_2 coating layer plays an important role in reducing the charge transfer resistance on the electrolyte–electrode interfaces. - Highlights: • MnO_2 coated LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 cathode material is synthesized for the first time. • MnO_2 offers available sites for insertion of extracted lithium. • The preserved surface and crystal structures results in the improved kinetics.

  15. Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

    KAUST Repository

    Zhu, Haibo; Ould-Chikh, Samy; Anjum, Dalaver Hussain; Sun, Miao; Biausque, Gregory; Basset, Jean-Marie; Caps, Valerie

    2012-01-01

    evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7-13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1-2 nm) of a niobium-rich mixed oxide with a structure similar

  16. Nb effect in the nickel oxide-catalyzed low-temperature oxidative dehydrogenation of ethane

    KAUST Repository

    Zhu, Haibo

    2012-01-01

    A method for the preparation of NiO and Nb-NiO nanocomposites is developed, based on the slow oxidation of a nickel-rich Nb-Ni gel obtained in citric acid. The resulting materials have higher surface areas than those obtained by the classical evaporation method from nickel nitrate and ammonium niobium oxalate. These consist in NiO nanocrystallites (7-13 nm) associated, at Nb contents >3 at.%., with an amorphous thin layer (1-2 nm) of a niobium-rich mixed oxide with a structure similar to that of NiNb 2O 6. Unlike bulk nickel oxides, the activity of these nanooxides for low-temperature ethane oxidative dehydrogenation (ODH) has been related to their redox properties. In addition to limiting the size of NiO crystallites, the presence of the Nb-rich phase also inhibits NiO reducibility. At Nb content >5 at.%, Nb-NiO composites are thus less active for ethane ODH but more selective, indicating that the Nb-rich phase probably covers part of the unselective, non-stoichiometric, active oxygen species of NiO. This geometric effect is supported by high-resolution transmission electron microscopy observations. The close interaction between NiO and the thin Nb-rich mixed oxide layer, combined with possible restructuration of the nanocomposite under ODH conditions, leads to significant catalyst deactivation at high Nb loadings. Hence, the most efficient ODH catalysts obtained by this method are those containing 3-4 at.% Nb, which combine high activity, selectivity, and stability. The impact of the preparation method on the structural and catalytic properties of Nb-NiO nanocomposites suggests that further improvement in NiO-catalyzed ethane ODH can be expected upon optimization of the catalyst. © 2011 Elsevier Inc. All rights reserved.

  17. Control of electrochemical properties of nickel-rich layered cathode materials for lithium ion batteries by variation of the manganese to cobalt ratio

    Science.gov (United States)

    Sun, Ho-Hyun; Choi, Wonchang; Lee, Joong Kee; Oh, In-Hwan; Jung, Hun-Gi

    2015-02-01

    Various Ni-rich layered oxide cathodes (above 0.80 Ni content), such as LiNi1-y-zCoyAlzO2 (NCA), are used in electric vehicles (EVs) due to their high capacity (∼200 mAh g-1 for NCA). However, to improve cycle performance and thermal stability and to ensure longer and safer usage, numerous studies have investigated surface modification, coating, and doping of cathode materials. In this study, we have investigated the characteristics of Li[Ni0.85CoxMn0.15-x]O2 with various Mn to Co ratios (x = 0-0.15) synthesized by a coprecipitation method. The discharge capacities of the Li[Ni0.85CoxMn0.15-x]O2 cathodes are similar at around 206 mAh g-1 at room temperature and 213.8 mAh g-1 at 55 °C between 2.7 and 4.3 V at a 0.2C rate, while the cyclability, thermal stability, and rate capability of all samples differ according to the Mn and Co ratio. The Li[Ni0.85Co0.05Mn0.10]O2 cathode shows the most promising electrochemical properties under different conditions among the various cathodes evaluated; it displays a high rate capacity (approximately 163 mAh g-1 at 5C rate) at 25 °C and good thermal stability (main exothermic temperature of 233.7 °C and relatively low heat evolution of 857.3 J g-1).

  18. Synthesis and electrochemical behavior of nanosized LiNi1-xCa xO2 cathode materials for high voltage secondary lithium-ion cells

    International Nuclear Information System (INIS)

    Sathiyamoorthi, R.; Vasudevan, T.

    2007-01-01

    A new class of LiNi 1-x Ca x O 2 (x = 0.0, 0.1, 0.2, 0.3 and 0.5) layered oxide materials has been synthesized by a simple low temperature solid-state route with mixed nitrates/urea with glycerol as the starting materials. First we have taken TG/DTA for observing the phase transformations of LiNi 0.9 Ca 0.1 O 2 . The structure of the synthesized oxides was analyzed using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) to identify the crystal structure and cation environment, respectively. The synthesized ceramic oxide battery materials were examined by using transmission electron microscope (TEM), scanning electron microscope (SEM) analysis to determine the particle size, nature and morphological structure. SEM with energy dispersive X-ray spectroscopic analysis (EDAX) analysis was carried out to explore the composition of the prepared materials. The electrochemical performance of LiNi 1-x Ca x O 2 electrodes was analyzed using cyclic voltammetry (CV) and galvanostatic charge-discharge cycling studies in the voltage range 3.0-4.5 V. Electrode made with cathode active material, acetylene black and poly(vinylidene difluoride) yield a discharge capacity of 178.1 mAh g -1 (x = 0.2) with good specific capacity over several charge-discharge cycles. These results have been also supported by cyclic voltammograms

  19. En route to the conductivity bottleneck in p-type CuCr1-xMxO2-ySy (M = Li, Mg)

    Science.gov (United States)

    Mandal, P.; Mazumder, N.; Akhtar, A. J.; Roy, R.; Chattopadhyay, K. K.

    2017-05-01

    We extend our material design concept [P. Mandal et al. J. Phys. D: Appl. Phys. 49, 275109, (2016); N. Mazumder et al. J. Phys. Chem. Lett. 4, 3539, (2013)] further aiming to overcome the conductivity bottleneck (1 Scm-1) in p-type transparent conducting oxide (TCO). In this work, we execute the strategy of simultaneous cationic-anionic hole doping in the prototype p-TCO CuCrO2. CuCr1-xMxO2-ySy (M = Li, Mg) is prepared by solid state heating at 1150 °C. Using Rietveld analysis, the presence of Mgcr•, Licr • and SO×areconfirmed and quantified. The diffuse reflectance (DR) spectra are acquired to determine the dominant optical gap (˜ 3.5 eV) and found to be affected little upon site selective hole doping. From temperature dependence (80 - 300 K) of DC conductivity (σdc), (Licr •+SO×)dopingcan be identified to be the more plausible alternative to reach the bottleneck threshold compared to (Mgcr •+SO×) albeit of smaller σdc at 300 K.

  20. Electrochemical performances of LiNi1−xMnxPO4 (x = 0.05–0.2) olivine cathode materials for high voltage rechargeable lithium ion batteries

    DEFF Research Database (Denmark)

    Karthikprabhu, S.; Karuppasamy, K.; Vikraman, Dhanasekaran

    2018-01-01

    This study demonstrated to synthesis of carbon-free lithium nickel phosphate (LiNiPO4) and its analogue of manganese doped LiNi1−xMnxPO4 (x = 0.05–0.2) cathode materials by a facile polyol method and their suitability for use in high voltage lithium ion batteries (LIBs). The physicochemical...

  1. Synthesis of 0.3Li2MnO3·0.7LiNi1/3Co1/3Mn1/3O2 cathode materials using 3-D urchin-like MnO2 as precursor for high performance lithium ion battery

    International Nuclear Information System (INIS)

    Zhao, Chenhao; Hu, Zhibiao; Zhou, Yunlong; Fang, Shuzhen; Cai, Shaohan

    2015-01-01

    In the paper, we report synthesis of lithium rich layered oxide 0.3Li 2 MnO 3 ·0.7LiNi 1/3 Co 1/3 Mn 1/3 O 2 by using an urchin-like MnO 2 as precursor. The influences of calcination temperatures on the structures and electrochemical performances of as-prepared materials are systematically studied. The results show that the obtained sample can partially retain the morphology of urchin-like precursor especially at low temperature, and a higher calcination temperature helps to improve the layered structure and particle size. As lithium ion battery cathodes, the 750 °C sample with the size of 100–200 nm reveals an optimal electrochemical performance. The initial discharge capacity of 234.6 mAh g −1 with high Coulombic efficiency of 84.6 % can be reached at 0.1C within 2.0–4.7 V. After 50 cycles, the capacity retention can reach 90.2 % at 0.5C. Even at high current density of 5C, the sample also shows a stable discharge capacity of 120.5 mAh g −1 . Anyways, the urchin-like MnO 2 directed route is suitable to prepare 0.3Li 2 MnO 3 ·0.7LiNi 1/3 Co 1/3 Mn 1/3 O 2 as lithium ion battery cathode

  2. Exposing the {010} Planes by Oriented Self-Assembly with Nanosheets To Improve the Electrochemical Performances of Ni-Rich Li[Ni0.8Co0.1Mn0.1]O2 Microspheres.

    Science.gov (United States)

    Su, Yuefeng; Chen, Gang; Chen, Lai; Li, Weikang; Zhang, Qiyu; Yang, Zhiru; Lu, Yun; Bao, Liying; Tan, Jing; Chen, Renjie; Chen, Shi; Wu, Feng

    2018-02-21

    A modified Ni-rich Li[Ni 0.8 Co 0.1 Mn 0.1 ]O 2 cathode material with exposed {010} planes is successfully synthesized for lithium-ion batteries. The scanning electron microscopy images have demonstrated that by tuning the ammonia concentration during the synthesis of precursors, the primary nanosheets could be successfully stacked along the [001] crystal axis predominantly, self-assembling like multilayers. According to the high-resolution transmission electron microscopy results, such a morphology benefits the growth of the {010} active planes of final layered cathodes during calcination treatment, resulting in the increased area of the exposed {010} active planes, a well-ordered layer structure, and a lower cation mixing disorder. The Li-ion diffusion coefficient has also been improved after the modification based on the results of potentiostatic intermittent titration technique. As a consequence, the modified Li[Ni 0.8 Co 0.1 Mn 0.1 ]O 2 material exhibits superior initial discharges of 201.6 mA h g -1 at 0.2 C and 185.7 mA h g -1 at 1 C within 2.8-4.3 V (vs Li + /Li), and their capacity retentions after 100 cycles reach 90 and 90.6%, respectively. The capacity at 10 C also increases from 98.3 to 146.5 mA h g -1 after the modification. Our work proposes a novel approach for exposing high-energy {010} active planes of the layered cathode material and again confirms its validity in improving electrochemical properties.

  3. Nickel Inhibits Mitochondrial Fatty Acid Oxidation

    Science.gov (United States)

    Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

    2015-01-01

    Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

  4. Synthetic Control of Kinetic Reaction Pathway and Cationic Ordering in High-Ni Layered Oxide Cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dawei [Sustainable Energy Technologies Department, Brookhaven National Laboratory, Upton NY 11973 USA; Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory Physical Chemistry Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen Fujian 361005 China; Kou, Ronghui [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Ren, Yang [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Sun, Cheng-Jun [X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Zhao, Hu [Sustainable Energy Technologies Department, Brookhaven National Laboratory, Upton NY 11973 USA; Zhang, Ming-Jian [Sustainable Energy Technologies Department, Brookhaven National Laboratory, Upton NY 11973 USA; School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen Guangdong 518055 P. R. China; Li, Yan [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL 60439 USA; Huq, Ashifia [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge TN 37831 USA; Ko, J. Y. Peter [The Cornell High Energy Synchrotron Source, Cornell University, Ithaca NY 14853 USA; Pan, Feng [School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen Guangdong 518055 P. R. China; Sun, Yang-Kook [Department of Energy Engineering, Hanyang University, Seoul 133-791 South Korea; Yang, Yong [Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory Physical Chemistry Solid Surfaces, Department of Chemistry, Xiamen University, Xiamen Fujian 361005 China; Amine, Khalil [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL 60439 USA; Bai, Jianming [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton NY 11973 USA; Chen, Zonghai [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL 60439 USA; Wang, Feng [Sustainable Energy Technologies Department, Brookhaven National Laboratory, Upton NY 11973 USA

    2017-08-25

    Nickel-rich layered transition metal oxides, LiNi1-x(MnCo)(x)O-2 (1-x >= 0.5), are appealing candidates for cathodes in next-generation lithium-ion batteries (LIBs) for electric vehicles and other large-scale applications, due to their high capacity and low cost. However, synthetic control of the structural ordering in such a complex quaternary system has been a great challenge, especially in the presence of high Ni content. Herein, synthesis reactions for preparing layered LiNi0.7Mn0.15Co0.15O2 (NMC71515) by solid-state methods are investigated through a combination of time-resolved in situ high-energy X-ray diffraction and absorption spectroscopy measurements. The real-time observation reveals a strong temperature dependence of the kinetics of cationic ordering in NMC71515 as a result of thermal-driven oxidation of transition metals and lithium/oxygen loss that concomitantly occur during heat treatment. Through synthetic control of the kinetic reaction pathway, a layered NMC71515 with low cationic disordering and a high reversible capacity is prepared in air. The findings may help to pave the way for designing high-Ni layered oxide cathodes for LIBs.

  5. ELECTROCHEMICAL DETERMINATION OF ETHANOL, 2- PROPANOL AND 1-BUTANOL ON GLASSY CARBON ELECTRODE MODIFIED WITH NICKEL OXIDE FILM

    Directory of Open Access Journals (Sweden)

    A. Benchettara

    2014-12-01

    Full Text Available In this work, we present the modification of a glassy carbon electrode with nickel oxide film which is performed in two successive steps. In the first one, the electrochemical deposition of metallic nickel on the glassy carbon electrode (GCE is achieved in 0.1M boric acid; in the second step, the metallic deposit is anodically oxidized in 0.1M NaOH. These two operations were carried out in a three electrode cell with a filiform platinum auxiliary electrode, a SCE as potential reference and a working microelectrode of modified glassy carbon with nickel oxides. This electrode is characterized by several electrochemical techniques and is used for the catalytic determination of ethanol, 2-propanol and 1-butanol in 0.1 M NaOH. The proposed chemical mechanism shows that NiO2 acts as a mediator.

  6. ELECTROCHEMICAL DETERMINATION OF ETHANOL, 2- PROPANOL AND 1-BUTANOL ON GLASSY CARBON ELECTRODE MODIFIED WITH NICKEL OXIDE FILM

    Directory of Open Access Journals (Sweden)

    A. Benchettara

    2015-07-01

    Full Text Available In this work, we present the modification of a glassy carbon electrode with nickel oxide film which is performed in two successive steps. In the first one, the electrochemical deposition of metallic nickel on the glassy carbon electrode (GCE is achieved in 0.1M boric acid; in the second step, the metallic deposit is anodically oxidized in 0.1M NaOH. These two operations were carried out in a three electrode cell with a filiform platinum auxiliary electrode, a SCE as potential reference and a working microelectrode of modified glassy carbon with nickel oxides. This electrode is characterized by several electrochemical techniques and is used for the catalytic determination of ethanol, 2-propanol and 1-butanol in 0.1 M NaOH. The proposed chemical mechanism shows that NiO2 acts as a mediator.

  7. Zn-Doped LiNi1/3Co1/3Mn1/3O2 Composite as Cathode Material for Lithium Ion Battery: Preparation, Characterization, and Electrochemical Properties

    Directory of Open Access Journals (Sweden)

    Han Du

    2015-01-01

    Full Text Available Zn-doped LiNi1/3Co1/3Mn1/3O2 composite, Li(Ni1/3Co1/3Mn1/31–xZnxO2 (x = 0.02; 0.05; 0.08, is synthesized by the sol-gel method. The crystal structure, morphology, and electrochemical performance are investigated via X-ray diffraction (XRD, scanning electron microscope (SEM, cyclic voltammetry (CV, and constant current charge/discharge experiment. The result reveals that Zn-doping cathode material can reach the initial charge/discharge capacity of 188.8/162.9 mAh·g−1 for Li(Ni1/3Co1/3Mn1/30.98Zn0.02O2 and 179.0/154.1 mAh·g−1 for Li(Ni1/3Co1/3Mn1/30.95Zn0.05O2 with the high voltage of 4.4 V at 0.1 C. Furthermore, the capacity retention of Li(Ni1/3Co1/3Mn1/30.98Zn0.02O2 is 95.1% at 0.5 C after 50 cycles at room temperature. The improved electrochemical properties of Zn-doped LiNi1/3Co1/3Mn1/3O2 are attributed to reduced electrode polarization, enhanced capacity reversibility, and excellent cyclic performance.

  8. Structural and thermal stabilities of layered Li(Ni 1/3Co 1/3Mn 1/3)O 2 materials in 18650 high power batteries

    Science.gov (United States)

    He, Yan-Bing; Ning, Feng; Yang, Quan-Hong; Song, Quan-Sheng; Li, Baohua; Su, Fangyuan; Du, Hongda; Tang, Zhi-Yuan; Kang, Feiyu

    The structural and thermal stabilities of the layered Li(Ni 1/3Co 1/3Mn 1/3)O 2 cathode materials under high rate cycling and abusive conditions are investigated using the commercial 18650 Li(Ni 1/3Co 1/3Mn 1/3)O 2/graphite high power batteries. The Li(Ni 1/3Co 1/3Mn 1/3)O 2 materials maintain their layered structure even when the power batteries are subjected to 200 cycles with 10 C discharge rate at temperatures of 25 and 50 °C, whereas their microstructure undergoes obvious distortion, which leads to the relatively poor cycling performance of power batteries at high charge/discharge rates and working temperature. Under abusive conditions, the increase in the battery temperature during overcharge is attributed to both the reactions of electrolyte solvents with overcharged graphite anode and Li(Ni 1/3Co 1/3Mn 1/3)O 2 cathode and the Joule heat that results from the great increase in the total resistance (R cell) of batteries. The reactions of fully charged Li(Ni 1/3Co 1/3Mn 1/3)O 2 cathodes and graphite anodes with electrolyte cannot be activated during short current test in the fully charged batteries. However, these reactions occur at around 140 °C in the fully charged batteries during oven test, which is much lower than the temperature of about 240 °C required for the reactions outside batteries.

  9. Improvement in high-voltage and high rate cycling performance of nickel-rich layered cathode materials via facile chemical vapor deposition with methane

    International Nuclear Information System (INIS)

    Hyuk Son, In; Park, Kwangjin; Hwan Park, Jong

    2017-01-01

    Nickel-rich layered-oxide materials are considered promising candidates for application as cathode material in high-energy lithium ion batteries. However, their cycling performance at high voltages and rate conditions require further improvement for the purpose of commercialization. Here, we report on the facile surface modification of nickel-rich layered oxide by chemical vapor deposition with methane which yields a conductive and protective artificial solid electrolyte interphase layer consisting of amorphous carbon, alkyl lithium carbonate, and lithium carbonate. We examine the mechanism of the protective layer formation and structural deformation of the nickel-rich layered oxide during chemical vapor deposition with methane. Via optimizing the reaction conditions, we improve the electrical conductivity as well as the interfacial stability of the nickel-rich layered oxide without inducing structural deformation. The surface-modified nickel-rich layered oxide exhibits an improved performance due to the resulting enhanced rate capability, high initial efficiency, and long cycle life at high voltage (>4.5 V).

  10. Standard Test Methods for Detecting Susceptibility to Intergranular Corrosion in Wrought, Nickel-Rich, Chromium-Bearing Alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 These test methods cover two tests as follows: 1.1.1 Method A, Ferric Sulfate-Sulfuric Acid Test (Sections 3-10, inclusive)—This test method describes the procedure for conducting the boiling ferric sulfate—50 % sulfuric acid test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to intergranular corrosion (see Terminology G 15), which may be encountered in certain service environments. The uniform corrosion rate obtained by this test method, which is a function of minor variations in alloy composition, may easily mask the intergranular corrosion components of the overall corrosion rate on alloys N10276, N06022, N06059, and N06455. 1.1.2 Method B, Mixed Acid-Oxidizing Salt Test (Sections 11-18, inclusive)—This test method describes the procedure for conducting a boiling 23 % sulfuric + 1.2 % hydrochloric + 1 % ferric chloride + 1 % cupric chloride test which measures the susceptibility of certain nickel-rich, chromium-bearing alloys to display a step function increa...

  11. Enthalpies of formation of layered LiNixMnxCo1-2xO2 (0 ≤ x ≤ 0.5) compounds as lithium ion battery cathode materials

    International Nuclear Information System (INIS)

    Masoumi, Maryam; Cupid, Damian M.; Reichmann, Thomas L.; Seifert, Hans J.; Chang, Keke; Music, Denis; Schneider, Jochen M.

    2017-01-01

    Layer-structured mixed transition metal oxides with the formula LiNi x Mn x Co 1-2x O 2 (0 ≤ x ≤ 0.5) are considered as important cathode materials for lithium-ion batteries. In an effort to evaluate the relative thermodynamic stabilities of individual compositions in this series, the enthalpies of formation of selected stoichiometries are determined by high temperature oxide melt drop solution calorimetry and verified by ab-initio calculations. The measured and calculated data are in good agreement with each other, and the results show that LiCoO 2 -LiNi 0.5 Mn 0.5 O 2 solid solution approaches ideal behavior. By increasing x, i.e. by equimolar substitution of Mn 4+ and Ni 2+ for Co 3+ , the enthalpy of formation of LiNi x Mn x Co 1-2x O 2 from the elements becomes more exothermic, implying increased energetic stability. This conclusion is in agreement with the literature results showing improved structural stability and cycling performance of Ni/Mn-rich LiNi x Mn x Co 1-2x O 2 compounds cycled to higher cut-off voltages.

  12. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    International Nuclear Information System (INIS)

    Jinlong, Lv; Tongxiang, Liang; Chen, Wang

    2016-01-01

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H_2SO_4 solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  13. Investigation of hydrogen evolution activity for the nickel, nickel-molybdenum nickel-graphite composite and nickel-reduced graphene oxide composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Jinlong, Lv, E-mail: ljlbuaa@126.com [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China); Tongxiang, Liang; Chen, Wang [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Zhongguancun Street, Haidian District, Beijing 100084 (China); State Key Lab of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China)

    2016-03-15

    Graphical abstract: - Highlights: • Improved HER efficiency of Ni-Mo coatings was attributed to ‘cauliflower’ like microstructure. • RGO in nickel-RGO composite coating promoted refined grain and facilitated HER. • Synergistic effect between nickel and RGO facilitated HER due to large specific surface of RGO. - Abstract: The nickel, nickel-molybdenum alloy, nickel-graphite and nickel-reduced graphene oxide composite coatings were obtained by the electrodeposition technique from a nickel sulfate bath. Nanocrystalline molybdenum, graphite and reduced graphene oxide in nickel coatings promoted hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. However, the nickel-reduced graphene oxide composite coating exhibited the highest electrocatalytic activity for the hydrogen evolution reaction in 0.5 M H{sub 2}SO{sub 4} solution at room temperature. A large number of gaps between ‘cauliflower’ like grains could decrease effective area for hydrogen evolution reaction in slight amorphous nickel-molybdenum alloy. The synergistic effect between nickel and reduced graphene oxide promoted hydrogen evolution, moreover, refined grain in nickel-reduced graphene oxide composite coating and large specific surface of reduced graphene oxide also facilitated hydrogen evolution reaction.

  14. Spinel formation for stabilizing simulated nickel-laden sludge with aluminum-rich ceramic precursors.

    Science.gov (United States)

    Shih, Kaimin; White, Tim; Leckie, James O

    2006-08-15

    The feasibility of stabilizing nickel-laden sludge from commonly available Al-rich ceramic precursors was investigated and accomplished with high nickel incorporation efficiency. To simulate the process, nickel oxide was mixed alternatively with gamma-alumina, corundum, kaolinite, and mullite and was sintered from 800 to 1480 degrees C. The nickel aluminate spinel (NiAl2O4) was confirmed as the stabilization phase for nickel and crystallized with efficiencies greater than 90% for all precursors above 1250 degrees C and 3-h sintering. The nickel-incorporation reaction pathways with these precursors were identified, and the microstructure and spinel yield were investigated as a function of sintering temperature with fixed sintering time. This study has demonstrated a promising process for forming nickel spinel to stabilize nickel-laden sludge from a wide range of inexpensive ceramic precursors, which may provide an avenue for economically blending waste metal sludges via the building industry processes to reduce the environmental hazards of toxic metals. The correlation of product textures and nickel incorporation efficiencies through selection of different precursors also provides the option of tailoring property-specific products.

  15. Processing of water-based LiNi1/3Mn1/3Co1/3O2 pastes for ...

    Indian Academy of Sciences (India)

    Results show that a substitution of the conventional organic solvent-based manufacturing route for LiNi1/3Mn1/3Co1/3O2 cathodes by water-based processing exhibits a promising way to realise Li-ion batteries with comparable electrochemical behaviour, while avoiding toxic processing aids and reducing overall ...

  16. Mitigating Voltage Decay of Li-Rich Cathode Material via Increasing Ni Content for Lithium-Ion Batteries.

    Science.gov (United States)

    Shi, Ji-Lei; Zhang, Jie-Nan; He, Min; Zhang, Xu-Dong; Yin, Ya-Xia; Li, Hong; Guo, Yu-Guo; Gu, Lin; Wan, Li-Jun

    2016-08-10

    Li-rich layered materials have been considered as the most promising cathode materials for future high-energy-density lithium-ion batteries. However, they suffer from severe voltage decay upon cycling, which hinders their further commercialization. Here, we report a Li-rich layered material 0.5Li2MnO3·0.5LiNi0.8Co0.1Mn0.1O2 with high nickel content, which exhibits much slower voltage decay during long-term cycling compared to conventional Li-rich materials. The voltage decay after 200 cycles is 201 mV. Combining in situ X-ray diffraction (XRD), ex situ XRD, ex situ X-ray photoelectron spectroscopy, and scanning transmission electron microscopy, we demonstrate that nickel ions act as stabilizing ions to inhibit the Jahn-Teller effect of active Mn(3+) ions, improving d-p hybridization and supporting the layered structure as a pillar. In addition, nickel ions can migrate between the transition-metal layer and the interlayer, thus avoiding the formation of spinel-like structures and consequently mitigating the voltage decay. Our results provide a simple and effective avenue for developing Li-rich layered materials with mitigated voltage decay and a long lifespan, thereby promoting their further application in lithium-ion batteries with high energy density.

  17. Synthesis of LiNi0.8Co0.1Mn0.1O2 cathode material by chloride co-precipitation method

    Institute of Scientific and Technical Information of China (English)

    李灵均; 李新海; 王志兴; 伍凌; 郑俊超; 李金辉

    2010-01-01

    LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical measurements.Effects of lithium ion content and sintering temperature on physical and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 were also investigated. The results show that the sample synthesized at 750℃with 105%lithium content has fine particle sizes around 200 nm and homogenous sizes distribution.The initial discharge capacity for the powder is 184 mA·h/g between 2.7 and 4.3 V at 0.1C and room temperature.

  18. Preparation, characteristics and electrochemical properties of surface-modified LiMn2O4 by doped LiNi0.05Mn1.95O4

    International Nuclear Information System (INIS)

    Yuan, Y.F.; Wu, H.M.; Guo, S.Y.; Wu, J.B.; Yang, J.L.; Wang, X.L.; Tu, J.P.

    2008-01-01

    The surface-modified spinel LiMn 2 O 4 by doped LiNi 0.05 Mn 1.95 O 4 was prepared by a tartaric acid gel method. Transmission electron microscope (TEM) images indicated that some small particles with 100-200 nm in diameter modified the surface of large particle LiMn 2 O 4 . Energy dispersive spectrometry (EDS) showed that the particles were LiNi 0.05 Mn 1.95 O 4 . Electrochemical properties of LiNi 0.05 Mn 1.95 O 4 -modified spinel LiMn 2 O 4 were intensively investigated by the galvanostatic charge-discharge tests, cyclic voltammetry (CV) and AC impedance measurements. The doped LiNi 0.05 Mn 1.95 O 4 -modified LiMn 2 O 4 cathode delivered the same initial discharge capacity as the unmodified LiMn 2 O 4 , but its cyclic stability was evidently improved, the capacity retention ratio reached 96% after 20 cycles, being higher than 89% of the unmodified LiMn 2 O 4 . Cyclic voltammograms of the LiNi 0.05 Mn 1.95 O 4 -modified LiMn 2 O 4 did not markedly change while the semicircle diameter of AC impedance spectra evidently decreased after 20 cycles, which showed that the surface modification with LiNi 0.05 Mn 1.95 O 4 improved the electrochemical activity and cycling stability of LiMn 2 O 4 .

  19. Kinetics and structural changes of Li-rich layered oxide 0.5Li2MnO3·0.5LiNi(0.292)Co(0.375)Mn(0.333)O2 material investigated by a novel technique combining in situ XRD and a multipotential step.

    Science.gov (United States)

    Shen, Chong-Heng; Huang, Ling; Lin, Zhou; Shen, Shou-Yu; Wang, Qin; Su, Hang; Fu, Fang; Zheng, Xiao-Mei

    2014-08-13

    Li-rich layered oxide 0.5Li2MnO3·0.5LiNi0.292Co0.375Mn0.333O2 was prepared by an aqueous solution-evaporation route. X-ray powder diffraction (XRD) showed that the as-synthesized material was a solid solution consisting of layered α-NaFeO2-type LiMO2 (M = Ni, Co, Mn) and monoclinic Li2MnO3. The superlattice spots in the selected area electron diffraction pattern indicated the ordering of lithium ions with transition metal (TM) ions in TM layers in this Li-rich layered oxide. Electrochemical performance testing showed that the as-synthesized material could deliver an initial discharge capacity of 267.7 mAh/g, with a capacity retention of 88.5% after 33 cycles. A new combination technique, multipotential step in situ XRD (MPS in situ XRD) measurement, was applied for the first time to investigate the Li-rich layered oxide. Using this approach, the relationships between kinetics and structural variations can be obtained simutaneously. In situ XRD results showed that the c parameter decreased from 3.70 to 4.30 V and increased from 4.30 to 4.70 V, whereas the a parameter underwent a decrease above 4.30 V during the first charge process. Below 3.90 V during the first discharge process, a slight decrease in the c parameter was found along with an increase in the a parameter. During the first charge process, the value of the coefficient of diffusion for lithium ions (DLi+) decreased to its mininum at 4.55 V, which might be associated with Ni(2+) migration, as indicated by both Ni occupancy in 3b sites (Ni3b%) in the Li(+) layers and complicated chemical reactions. Remarkably, a lattice distortion might occur within the local domain in the host stucture during the first discharge process, indicated by a slight splitting of the (003) diffraction peak at 3.20 V.

  20. A novel process for recycling and resynthesizing LiNi1/3Co1/3Mn1/3O2 from the cathode scraps intended for lithium-ion batteries

    International Nuclear Information System (INIS)

    Zhang, Xihua; Xie, Yongbing; Cao, Hongbin; Nawaz, Faheem; Zhang, Yi

    2014-01-01

    Highlights: • A simple process to recycle cathode scraps intended for lithium-ion batteries. • Complete separation of the cathode material from the aluminum foil is achieved. • The recovered aluminum foil is highly pure. • LiNi 1/3 Co 1/3 Mn 1/3 O 2 is directly resynthesized from the separated cathode material. - Abstract: To solve the recycling challenge for aqueous binder based lithium-ion batteries (LIBs), a novel process for recycling and resynthesizing LiNi 1/3 Co 1/3 Mn 1/3 O 2 from the cathode scraps generated during manufacturing process is proposed in this study. Trifluoroacetic acid (TFA) is employed to separate the cathode material from the aluminum foil. The effects of TFA concentration, liquid/solid (L/S) ratio, reaction temperature and time on the separation efficiencies of the cathode material and aluminum foil are investigated systematically. The cathode material can be separated completely under the optimal experimental condition of 15 vol.% TFA solution, L/S ratio of 8.0 mL g −1 , reacting at 40 °C for 180 min along with appropriate agitation. LiNi 1/3 Co 1/3 Mn 1/3 O 2 is successfully resynthesized from the separated cathode material by solid state reaction method. Several kinds of characterizations are performed to verify the typical properties of the resynthesized LiNi 1/3 Co 1/3 Mn 1/3 O 2 powder. Electrochemical tests show that the initial charge and discharge capacities of the resynthesized LiNi 1/3 Co 1/3 Mn 1/3 O 2 are 201 mAh g −1 and 155.4 mAh g −1 (2.8–4.5 V, 0.1 C), respectively. The discharge capacity remains at 129 mAh g −1 even after 30 cycles with a capacity retention ratio of 83.01%

  1. Hydrogen peroxide assisted synthesis of LiNi1/3Co1/3Mn1/3O2 as high-performance cathode for lithium-ion batteries

    Science.gov (United States)

    Lin, Chaohong; Zhang, Yongzhi; Chen, Li; Lei, Ying; Ou, Junke; Guo, Yong; Yuan, Hongyan; Xiao, Dan

    2015-04-01

    LiNi1/3Co1/3Mn1/3O2 (NCM) is a promising cathode material for lithium-ion battery. In this research, a facile co-precipitation process is employed, during which the mixed solution of NH3·H2O, H2O2 (30% aqueous solution) and LiOH·H2O is added into the nitrate solution. Notably, H2O2 is introduced as the oxidant and dispersant during the co-precipitation process to oxidize the metal ions and decrease the agglomeration of the precursor by giving out O2, and then improves the specific capacity, stability and energy density of NCM. Additionally, O3 is employed to further oxidize NCM to enhance the stability during the calcination process. The obtained NCM material with single crystal structure exhibits a high initial discharge specific capacity of 208.9 mAh g-1 at 0.1 C (1 C = 280 mA g-1), an excellent cycle stability with high retained capacity of 176.3 mAh g-1 after 50 cycles, and a high initial discharge specific capacities of 150.6 mAh g-1 at 5 C even at a high cutoff potential (4.6 V).

  2. Structural and compositional optimization of the LiNi0.8Co0.2O2 electrode by new synthesis conditions

    International Nuclear Information System (INIS)

    Mosqueda L, Y.; Milian P, C. R.; Pomares A, M.; Rodriguez H, J.; Perez C, E.

    2012-01-01

    The optimization of citrate precursor method to obtain the LiNi 0.8 Co 0.2 O 2 oxide from the thermal decomposition of the citrate precursor (NH 4 ) 3 LiNi 0.8 Co 0.2 (C 6 H 5 O 7 ) is presented. The optimization procedure consists of both the lithium atmosphere and the reaction time control during the decomposition of the citrate precursor. Were obtained and characterized two kind of the (Li l-x Ni x )(Ni 0.8 Co 0.2 )O 2 oxides, with and without optimized synthesis conditions, identified as A and B oxides, respectively. The A and B oxides are characterized by compositional, structural and electrochemical studies. The results showed that is possible to reach the ordered oxide phase at smaller reaction time if the lithium atmosphere is controlled. From the combination of the chemical analysis by Icp and the DRX Rietveld structural refinement it is possible to establish the Li, Ni(II), Ni(III) and Co(III) composition with great accuracy. The resulted structural and compositional transformations have a close relation with technological parameters of the rechargeable lithium battery using Li Ni 0.8 Co 0.2 O 2 oxide as cathode. (Author)

  3. Al2O3 Coated Concentration-Gradient Li[Ni0.73Co0.12Mn0.15]O2 Cathode Material by Freeze Drying for Long-Life Lithium Ion Batteries

    International Nuclear Information System (INIS)

    Wang, Jingpeng; Du, Chunyu; Yan, Chunqiu; He, Xiaoshu; Song, Bai; Yin, Geping; Zuo, Pengjian; Cheng, Xinqun

    2015-01-01

    Highlights: • Al 2 O 3 -coated concentration-gradient oxide is synthesized by a freeze drying method. • The effect of Al 2 O 3 -coating on concentration-gradient cathode is firstly studied. • Al 2 O 3 -coated sample exhibits high capacity and significantly enhanced cyclability. • Improved cyclability is ascribed to the effective protection of uniform Al 2 O 3 layer. - Abstract: In order to enhance the electrochemical performance of the high capacity layered oxide cathode with a Ni-rich core and a concentration-gradient shell (NRC-CGS), we use a freeze drying method to coat Al 2 O 3 layer onto the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, charge-discharge measurements and electrochemical impedance spectroscopy. It is revealed that an amorphous Al 2 O 3 layer of about 5 nm in thickness is uniformly formed on the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material by the freeze drying procedure. The freeze drying Al 2 O 3 -coated (FD-Al 2 O 3 -coated) sample demonstrates similar discharge capacity and significantly enhanced cycling performances, in comparison to the pristine and conventional heating drying Al 2 O 3 -coated (HD-Al 2 O 3 -coated) samples. The capacity decay rate of FD-Al 2 O 3 -coated Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material is 1.7% after 150 cycles at 55 °C, which is 9 and 12 times lower than that of the pristine and HD-Al 2 O 3 -coated samples. The superior electrochemical stability of the FD-Al 2 O 3 -coated sample is attributed to the synergistic protection of CGS and high-quality Al 2 O 3 coating that effectively protect the active material from electrolyte attack. The freeze drying process provides an effective method to prepare the high performance surface-coated electrode materials

  4. Leaching process for recovering valuable metals from the LiNi1/3Co1/3Mn1/3O2 cathode of lithium-ion batteries.

    Science.gov (United States)

    He, Li-Po; Sun, Shu-Ying; Song, Xing-Fu; Yu, Jian-Guo

    2017-06-01

    In view of the importance of environmental protection and resource recovery, recycling of spent lithium-ion batteries (LIBs) and electrode scraps generated during manufacturing processes is quite necessary. An environmentally sound leaching process for the recovery of Li, Ni, Co, and Mn from spent LiNi 1/3 Co 1/3 Mn 1/3 O 2 -based LIBs and cathode scraps was investigated in this study. Eh-pH diagrams were used to determine suitable leaching conditions. Operating variables affecting the leaching efficiencies for Li, Ni, Co, and Mn from LiNi 1/3 Co 1/3 Mn 1/3 O 2 , such as the H 2 SO 4 concentration, temperature, H 2 O 2 concentration, stirring speed, and pulp density, were investigated to determine the most efficient conditions for leaching. The leaching efficiencies for Li, Ni, Co, and Mn reached 99.7% under the optimized conditions of 1M H 2 SO 4 , 1vol% H 2 O 2 , 400rpm stirring speed, 40g/L pulp density, and 60min leaching time at 40°C. The leaching kinetics of LiNi 1/3 Co 1/3 Mn 1/3 O 2 were found to be significantly faster than those of LiCoO 2 . Based on the variation in the weight fraction of the metal in the residue, the "cubic rate law" was revised as follows: θ(1-f) 1/3 =(1-kt/r 0 ρ), which could characterize the leaching kinetics optimally. The activation energies were determined to be 64.98, 65.16, 66.12, and 66.04kJ/mol for Li, Ni, Co, and Mn, respectively, indicating that the leaching process was controlled by the rate of surface chemical reactions. Finally, a simple process was proposed for the recovery of valuable metals from spent LiNi 1/3 Co 1/3 Mn 1/3 O 2 -based LIBs and cathode scraps. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Spectrochemical analysis of impurities in nickel and in nickel oxide

    International Nuclear Information System (INIS)

    Goldbart, Z.; Lorber, A.; Harel, A.

    1981-11-01

    Various spectrochemical methods are described for the quantitative determination of 23 impurities in metallic nickel and in nickel oxide. The average limit of detection is from 1 to 5 ppm and the dynamic range lies over 2.5 orders of magnitude. The elements that were determined are: Al,B,Ba,Bi,Ca,Cd,Co,Cu,Fe,Ga,Ge,In,Mg,Mn,Mo,Nb,Si,Sn,Sr,Ti,Cr,V. (author)

  6. Uncovering a facile large-scale synthesis of LiNi1/3Co1/3Mn1/3O2 nanoflowers for high power lithium-ion batteries

    Science.gov (United States)

    Hua, Wei-Bo; Guo, Xiao-Dong; Zheng, Zhuo; Wang, Yan-Jie; Zhong, Ben-He; Fang, Baizeng; Wang, Jia-Zhao; Chou, Shu-Lei; Liu, Heng

    2015-02-01

    Developing advanced electrode materials that deliver high energy at ultra-fast charge and discharge rates are very crucial to meet an increasing large-scale market demand for high power lithium ion batteries (LIBs). A three-dimensional (3D) nanoflower structure is successfully developed in the large-scale synthesis of LiNi1/3Co1/3Mn1/3O2 material for the first time. The fast co-precipitation is the key technique to prepare the nanoflower structure in our method. After heat treatment, the obtained LiNi1/3Co1/3Mn1/3O2 nanoflowers (NL333) pronouncedly present a pristine flower-like nano-architecture and provide fast pathways for the transport of Li-ions and electrons. As a cathode material in a LIB, the prepared NL333 electrode demonstrates an outstanding high-rate capability. Particularly, in a narrow voltage range of 2.7-4.3 V, the discharge capacity at an ultra-fast charge-discharge rate (20C) is up to 126 mAh g-1, which reaches 78% of that at 0.2C, and is much higher than that (i.e., 44.17%) of the traditional bulk LiNi1/3Co1/3Mn1/3O2.

  7. Hydrogen-water deuterium exchange over metal oxide promoted nickel catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sagert, N H; Shaw-Wood, P E; Pouteau, R M.L. [Atomic Energy of Canada Ltd., Pinawa, Manitoba. Whiteshell Nuclear Research Establishment

    1975-11-01

    Specific rates have been measured for hydrogen-water deuterium isotope exchange over unsupported nickel promoted with about 20% of various metal oxides. The oxides used were Cr/sub 2/O/sub 3/, MoO/sub 2/, MnO, WO/sub 2/-WO/sub 3/, and UO/sub 2/. Nickel surface areas, which are required to measure the specific rates, were determined by hydrogen chemisorption. Specific rates were measured as a function of temperature in the range 353 to 573 K and as a function of the partial pressure of hydrogen and water over a 10-fold range of partial pressure. The molybdenum and tungsten oxides gave the highest specific rates, and manganese and uranium oxides the lowest. Chromium oxide was intermediate, although it gave the highest rate per gram of catalyst. The orders with respect to hydrogen and water over molybdenum oxide and tungsten oxide promoted nickel were consistent with a mechanism in which nickel oxide is formed from the reaction of water with the catalyst, and then is reduced by hydrogen. Over manganese and uranium oxide promoted catalysts, these orders are consistent with a mechanism in which adsorbed water exchanges with chemisorbed hydrogen atoms on the nickel surface. Chromium oxide is intermediate. It was noted that those oxides which favored the nickel oxide route had electronic work functions closest to those of metallic nickel and nickel oxide.

  8. OXIDATIVE-REFORMING OF METHANE AND PARTIAL OXIDATION OF METHANE REACTIONS OVER NiO/PrO2/ZrO2 CATALYSTS: EFFECT OF NICKEL CONTENT

    Directory of Open Access Journals (Sweden)

    Y. J. O. Asencios

    Full Text Available Abstract In this work the behavior of NiO-PrO2-ZrO2 catalysts containing various nickel loadings was evaluated in the partial oxidation of methane and oxidative-reforming reactions of methane. The catalysts were characterized by X-Ray Diffraction Analysis (in situ-XRD, Temperature Programmed Reduction (H2-TPR, Scanning Electron Microscopy (SEM/EDX and Adsorption-Desorption of nitrogen (BET area. The reactions were carried out at 750 °C and 1 atm for 5 hours. The catalysts were studied with different nickel content: 0, 5, 10 and 15% (related to total weight of catalyst, wt%. In both reactions, the catalyst containing the mixture of the three oxides (NiO/PrO2/ZrO2 with 15% nickel (15NiPrZr catalyst showed the best activity for the conversion of the reactants into Syngas and showed high selectivity for H2 and CO. The results suggest that the promoter PrO2 and the Niº centers are in a good proportion in the catalyst with 15% Ni. Our results showed that low nickel concentrations in the catalyst led to high metallic dispersion; however, very low nickel concentrations did not favor the methane transformation into Syngas. The catalyst containing only NiO/ZrO2 in the mixture was not sufficient for the catalysis. The presence of the promoter PrO2 was very important for the catalysis of the POM.

  9. Improve electrochemical performance of CeO2 surface modification LiNi0.80Co0.15Al0.05O2 cathode material

    Science.gov (United States)

    Xia, Shubiao; Zhang, Yingjie; Dong, Peng; Zhang, Yannan

    2014-06-01

    Lithium ion battery cathode material LiNi0.8Co0.15Al0.05O2 cathode has successfully prepared by co-precipitation. CeO2 surface modification has improved LiNi0.80Co0.15Al0.05O2 electrochemical performance use sol-gel method and subsequent heat treatment at 600 °C for 5 h. Different to other conventional coating material, CeO2 coating layer can not only inhibit the reaction of the electrode and the electrolyte, but also can reduce the impedance of electron transfer due to its high conductivity, and inhibit the production of Ni2+ because of its high oxidation. The surface-modified and pristine LiNi0.80Co0.15Al0.05O2 powders are characterized by XRD, SEM, TEM, XPS, CV and DSC. When CeO2 coating is 0.02% (mole ratio), contrast to pristine NCA, the CeO2-coated NCA cathode exhibits no decrease in its initial specific capacity of 184 mAh g -1 (at 0.2 C) and excellent capacity retention (86% of its initial capacity at 1 C) between 2.75 and 4.3 V after 100 cycles. The results indicate that the CeO2 surface treatment should be an effective way to improve cycle properties due to CeO2 inhibit the electrodes and the electrolyte side effects.

  10. Surface Surgery of the Nickel-Rich Cathode Material LiNi0.815Co0.15Al0.035O2: Toward a Complete and Ordered Surface Layered Structure and Better Electrochemical Properties.

    Science.gov (United States)

    Tang, Zhongfeng; Bao, Junjie; Du, Qingxia; Shao, Yu; Gao, Minghao; Zou, Bangkun; Chen, Chunhua

    2016-12-21

    A complete and ordered layered structure on the surface of LiNi 0.815 Co 0.15 Al 0.035 O 2 (NCA) has been achieved via a facile surface-oxidation method with Na 2 S 2 O 8 . The field-emission transmission electron microscopy images clearly show that preoxidation of the hydroxide precursor can eliminate the crystal defects and convert Ni(OH) 2 into layered β-NiOOH, which leads to a highly ordered crystalline NCA, with its (006) planes perpendicular to the surface in the sintering process. X-ray photoelectron spectroscopy and Raman shift results demonstrate that the contents of Ni 2+ and Co 2+ ions are reduced with preoxidization on the surface of the hydroxide precursor. The level of Li + /Ni 2+ disordering in the modified NCA determined by the peak intensity ratio I (003) /I (104) in X-ray diffraction patterns decreases. Thanks to the complete and ordered layered structure on the surface of secondary particles, lithium ions can easily intercalate/extract in the discharging-charging process, leading to greatly improved electrochemical properties.

  11. Li3PO4 surface coating on Ni-rich LiNi0.6Co0.2Mn0.2O2 by a citric acid assisted sol-gel method: Improved thermal stability and high-voltage performance

    Science.gov (United States)

    Lee, Suk-Woo; Kim, Myeong-Seong; Jeong, Jun Hui; Kim, Dong-Hyun; Chung, Kyung Yoon; Roh, Kwang Chul; Kim, Kwang-Bum

    2017-08-01

    A surface coating of Li3PO4 was applied to a Ni-rich LiNi0.6Co0.2Mn0.2O2 (NCM) material to improve its thermal stability and electrochemical properties via a citric acid assisted sol-gel method. The addition of citric acid effectively suppressed the instant formation of Li3PO4 in solution, resulting in successful coating of the NCM surface. The improved thermal stability of NCM after Li3PO4 surface coating was demonstrated by differential scanning calorimetry (DSC) analysis and in situ time-resolved X-ray diffraction (TR-XRD). In particular, the TR-XRD results showed that the improved thermal stability after Li3PO4 surface coating originates from suppression of the phase transition of charged NCM at high temperatures. Furthermore, the charge-discharge tests demonstrated that Li3PO4-coated LiNi0.6Co0.2Mn0.2O2 (LP-NCM) has excellent electrochemical properties. LP-NCM exhibited a specific capacity of 192.7 mAh g-1, a capacity retention of 44.1% at 10 C, and a capacity retention of 79.7% after 100 cycles at a high cut-off voltage of 4.7 V; these values represent remarkably improved electrochemical properties compared with those of bare NCM. These improved thermal and electrochemical properties were mainly attributed to the improvement of the structural stability of the material and the suppression of the interface reaction between the cathode and the electrolyte owing to the Li3PO4 coating.

  12. Hydrothermal synthesis of layered Li[Ni1/3Co1/3Mn1/3]O2 as positive electrode material for lithium secondary battery

    International Nuclear Information System (INIS)

    Myung, Seung-Taek; Lee, Myung-Hun; Komaba, Shinichi; Kumagai, Naoaki; Sun, Yang-Kook

    2005-01-01

    In attempts to prepare layered Li[Ni 1/3 Co 1/3 Mn 1/3 ]O 2 , hydrothermal method was employed. The hydrothermal precursor, [Ni 1/3 Co 1/3 Mn 1/3 ](OH) 2 , was synthesized via a coprecipitation route. The sphere-shaped powder precursor was hydrothermally reacted with LiOH aqueous solution at 170 deg. C for 4 days in autoclave. From X-ray diffraction and scanning electron microscopic studies, it was found that the as-hydrothermally prepared powders were crystallized to layered α-NaFeO 2 structure and the particles had spherical shape. The as-prepared Li[Ni 1/3 Co 1/3 Mn 1/3 ]O 2 delivered an initial discharge of about 110 mA h g -1 due to lower crystallinity. Heat treatment of the hydrothermal product at 800 deg. C was significantly effective to improve the structural integrity, which consequently affected the increase in the discharge capacity to 157 (4.3 V cut-off) and 182 mA h g -1 (4.6 V cut-off) at 25 deg. C with good reversibility

  13. Oxidation mechanism and passive behaviour of nickel in molten carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Vossen, J.P.T. (ECN Fossil Fuels, Petten (Netherlands)); Ament, P.C.H.; De Wit, J.H.W. (Div. of Corrosion, Lab. for Maaterials Sceince, Delft Univ. of Technology, Delft (Netherlands))

    1994-07-01

    The oxidation and passivation mechanism and the passive behaviour of nickel in molten carbonate have been investigated with impedance measurements. The oxidation of nickel proceeds according to a dissolution and reprecipitation process. The slowest steps in the reaction sequence are the dissociation reaction of the carbonate and the diffusion of the formed NiO to the metal surface. In the passive range, dissolution of Ni[sup 2+] proceeds after diffusion of Ni[sup 2+] through the oxide layer. The Ni[sup 2+] is formed at the metal/oxide interface. The slowest process is the diffusion of bivalent nickel ions through the passive scale. The formation of trivalent nickel ions probably takes place at the oxide/melt interface. This reaction is accompanied by the incorporation of an oxygen ion and a nickel vacancy in the NiO lattice. The trivalent nickel ions and the nickel vacancy diffuse to the bulk of the oxide scale. The slowest step in this sequence is the dissociation of the carbonate ions and the incorporation of the oxygen ion in the NiO lattice. 9 figs., 2 tabs., 11 refs.

  14. General Approach to Prepare 0.33Li₂MnO₃ · 0.67LiNi1/3Co1/3Mn1/3O₂ Hollow Microspheres for High Performance Lithium Ion Batteries.

    Science.gov (United States)

    Li, Jingfa; Xu, Wenjin; Zhang, Lei; Li, Min

    2018-06-01

    Li-excess manganese-based oxide layered structures, have drawn increasing interests as the promising cathodes to succeed the conventional LiCoO2 in lithium ion batteries (LIBs). It could deliver a higher energy density and output potential, as well as the nature of environment benign and low cost. Pristine Li-excess manganese-based oxides however suffer from poor rate capacity and voltage fading after cycling, and their inherent capacity limits of bulk size in performance. Micro-/Nanostructured electrode materials are considered to hold the key to overcome these thresholds. This paper reports a general approach to prepare 0.33Li2MnO3 · 0.67LiNi1/3Co1/3Mn1/3O2 microspheres with pores and void space, which benefits improving both the capacity and cyclability. The electrode made of hollow 0.33Li2MnO3 · 0.67LiNi1/3Co1/3Mn1/3O2 microspheres exhibits a 224 mAh g-1 discharge capacity over 200 cycles at 0.25 C rate, and 195 mAh g-1 at 5.0 C rate. These results indicated good perspective of hollow microspheres for practical battery applications.

  15. High energy density asymmetric supercapacitors with a nickel oxide nanoflake cathode and a 3D reduced graphene oxide anode.

    Science.gov (United States)

    Luan, Feng; Wang, Gongming; Ling, Yichuan; Lu, Xihong; Wang, Hanyu; Tong, Yexiang; Liu, Xiao-Xia; Li, Yat

    2013-09-07

    Here we demonstrate a high energy density asymmetric supercapacitor with nickel oxide nanoflake arrays as the cathode and reduced graphene oxide as the anode. Nickel oxide nanoflake arrays were synthesized on a flexible carbon cloth substrate using a seed-mediated hydrothermal method. The reduced graphene oxide sheets were deposited on three-dimensional (3D) nickel foam by hydrothermal treatment of nickel foam in graphene oxide solution. The nanostructured electrodes provide a large effective surface area. The asymmetric supercapacitor device operates with a voltage of 1.7 V and achieved a remarkable areal capacitance of 248 mF cm(-2) (specific capacitance of 50 F g(-1)) at a charge/discharge current density of 1 mA cm(-2) and a maximum energy density of 39.9 W h kg(-1) (based on the total mass of active materials of 5.0 mg). Furthermore, the device showed an excellent charge/discharge cycling performance in 1.0 M KOH electrolyte at a current density of 5 mA cm(-2), with a capacitance retention of 95% after 3000 cycles.

  16. High energy density asymmetric supercapacitors with a nickel oxide nanoflake cathode and a 3D reduced graphene oxide anode

    Science.gov (United States)

    Luan, Feng; Wang, Gongming; Ling, Yichuan; Lu, Xihong; Wang, Hanyu; Tong, Yexiang; Liu, Xiao-Xia; Li, Yat

    2013-08-01

    Here we demonstrate a high energy density asymmetric supercapacitor with nickel oxide nanoflake arrays as the cathode and reduced graphene oxide as the anode. Nickel oxide nanoflake arrays were synthesized on a flexible carbon cloth substrate using a seed-mediated hydrothermal method. The reduced graphene oxide sheets were deposited on three-dimensional (3D) nickel foam by hydrothermal treatment of nickel foam in graphene oxide solution. The nanostructured electrodes provide a large effective surface area. The asymmetric supercapacitor device operates with a voltage of 1.7 V and achieved a remarkable areal capacitance of 248 mF cm-2 (specific capacitance of 50 F g-1) at a charge/discharge current density of 1 mA cm-2 and a maximum energy density of 39.9 W h kg-1 (based on the total mass of active materials of 5.0 mg). Furthermore, the device showed an excellent charge/discharge cycling performance in 1.0 M KOH electrolyte at a current density of 5 mA cm-2, with a capacitance retention of 95% after 3000 cycles.

  17. Nickel exposure induces oxidative damage to mitochondrial DNA in Neuro2a cells: the neuroprotective roles of melatonin.

    Science.gov (United States)

    Xu, Shang-Cheng; He, Min-Di; Lu, Yong-Hui; Li, Li; Zhong, Min; Zhang, Yan-Wen; Wang, Yuan; Yu, Zheng-Ping; Zhou, Zhou

    2011-11-01

    Recent studies suggest that oxidative stress and mitochondrial dysfunction play important roles in the neurotoxicity of nickel. Because mitochondrial DNA (mtDNA) is highly vulnerable to oxidative stress and melatonin can efficiently protect mtDNA against oxidative damage in various pathological conditions, the aims of this study were to determine whether mtDNA oxidative damage was involved in the neurotoxicity of nickel and to assay the neuroprotective effects of melatonin in mtDNA. In this study, we exposed mouse neuroblastoma cell lines (Neuro2a) to different concentrations of nickel chloride (NiCl(2), 0.125, 0.25, and 0.5 mm) for 24 hr. We found that nickel significantly increased reactive oxygen species (ROS) production and mitochondrial superoxide levels. In addition, nickel exposure increased mitochondrial 8-hydroxyguanine (8-OHdG) content and reduced mtDNA content and mtDNA transcript levels. Consistent with this finding, nickel was found to destroy mtDNA nucleoid structure and decrease protein levels of Tfam, a key protein component for nucleoid organization. However, all the oxidative damage to mtDNA induced by nickel was efficiently attenuated by melatonin pretreatment. Our results suggest that oxidative damage to mtDNA may account for the neurotoxicity of nickel. Melatonin has great pharmacological potential in protecting mtDNA against the adverse effects of nickel in the nervous system. © 2011 John Wiley & Sons A/S.

  18. Nickel exposure and plasma levels of biomarkers for assessing oxidative stress in nickel electroplating workers.

    Science.gov (United States)

    Tsao, Yu-Chung; Gu, Po-Wen; Liu, Su-Hsun; Tzeng, I-Shiang; Chen, Jau-Yuan; Luo, Jiin-Chyuan John

    2017-07-01

    The mechanism of nickel-induced pathogenesis remains elusive. To examine effects of nickel exposure on plasma oxidative and anti-oxidative biomarkers. Biomarker data were collected from 154 workers with various levels of nickel exposure and from 73 controls. Correlations between nickel exposure and oxidative and anti-oxidative biomarkers were determined using linear regression models. Workers with a exposure to high nickel levels had significantly lower levels of anti-oxidants (glutathione and catalase) than those with a lower exposure to nickel; however, only glutathione showed an independent association after multivariable adjustment. Exposure to high levels of nickel may reduce serum anti-oxidative capacity.

  19. Capacity fade of LiNi(1-x-y)CoxAlyO2 cathode for lithium-ion batteries during accelerated calendar and cycle life test. I. Comparison analysis between LiNi(1-x-y)CoxAlyO2 and LiCoO2 cathodes in cylindrical lithium-ion cells during long term storage test

    Science.gov (United States)

    Watanabe, Shoichiro; Kinoshita, Masahiro; Nakura, Kensuke

    2014-02-01

    Ni-based LiNi(1-x-y)CoxAlyO2 (NCA) and LiCoO2 (LCO) cathode materials taken out of lithium-ion cells after storage for 2 years at 45 °C were analyzed by various spectroscopic techniques. X-ray photoelectron spectroscopy exhibited that there was no difference between NCA and LCO. On the other hand, scanning transmission electron microscopy-electron energy-loss spectroscopy demonstrated there was a remarkably large difference between the two cathode materials. Ni-L2,3 energy-loss near-edge structure (ELNES) spectra of the NCA showed a peak at about 856.5 eV, which was assigned to trivalent nickel, was maintained even after storage, indicating that the NCA had no significant change in its surface structure during storage. On the other hand, in the Co-L2,3 ELNES spectra of the LCO a peak at about 782.5 eV, which was assigned to trivalent cobalt, significantly shifted to the lower energies after storage. These results suggest that crystal structure change of the active material surface is a predominant reason of deterioration during the storage test.

  20. Oxidation characteristics of porous-nickel prepared by powder metallurgy and cast-nickel at 1273 K in air for total oxidation time of 100 h

    Directory of Open Access Journals (Sweden)

    Lamiaa Z. Mohamed

    2017-11-01

    Full Text Available The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravimetrically. The topography and the cross-section microstructure of each oxidized sample were observed using optical and scanning electron microscopy. X-ray diffractometry and X-ray energy dispersive analysis were used to determine the nature of the formed oxide phases. The kinetic results revealed that the porous-nickel samples had higher trend for irreproducibility. The average oxidation rate for porous- and cast-nickel samples was initially rapid, and then decreased gradually to become linear. Linear rate constants were 5.5 × 10−8 g/cm2 s and 3.4 × 10−8 g/cm2 s for the porous- and cast-nickel samples, respectively. Initially a single-porous non-adherent NiO layer was noticed on the porous- and cast-nickel samples. After a longer time of oxidation, a non-adherent duplex NiO scale was formed. The two layers of the duplex scales were different in color. NiO particles were observed in most of the pores of the porous-nickel samples. Finally, the linear oxidation kinetics and the formation of porous non-adherent duplex oxide scales on the inhomogeneous nickel substrates demonstrated that the addition of new layers of NiO occurred at the scale/metal interface due to the thermodynamically possible reaction between Ni and the molecular oxygen migrating inwardly.

  1. Oxidation characteristics of porous-nickel prepared by powder metallurgy and cast-nickel at 1273 K in air for total oxidation time of 100 h.

    Science.gov (United States)

    Mohamed, Lamiaa Z; Ghanem, Wafaa A; El Kady, Omayma A; Lotfy, Mohamed M; Ahmed, Hafiz A; Elrefaie, Fawzi A

    2017-11-01

    The oxidation behavior of two types of inhomogeneous nickel was investigated in air at 1273 K for a total oxidation time of 100 h. The two types were porous sintered-nickel and microstructurally inhomogeneous cast-nickel. The porous-nickel samples were fabricated by compacting Ni powder followed by sintering in vacuum at 1473 K for 2 h. The oxidation kinetics of the samples was determined gravimetrically. The topography and the cross-section microstructure of each oxidized sample were observed using optical and scanning electron microscopy. X-ray diffractometry and X-ray energy dispersive analysis were used to determine the nature of the formed oxide phases. The kinetic results revealed that the porous-nickel samples had higher trend for irreproducibility. The average oxidation rate for porous- and cast-nickel samples was initially rapid, and then decreased gradually to become linear. Linear rate constants were 5.5 × 10 -8  g/cm 2  s and 3.4 × 10 -8  g/cm 2  s for the porous- and cast-nickel samples, respectively. Initially a single-porous non-adherent NiO layer was noticed on the porous- and cast-nickel samples. After a longer time of oxidation, a non-adherent duplex NiO scale was formed. The two layers of the duplex scales were different in color. NiO particles were observed in most of the pores of the porous-nickel samples. Finally, the linear oxidation kinetics and the formation of porous non-adherent duplex oxide scales on the inhomogeneous nickel substrates demonstrated that the addition of new layers of NiO occurred at the scale/metal interface due to the thermodynamically possible reaction between Ni and the molecular oxygen migrating inwardly.

  2. Template-free approach to synthesize hierarchical porous nickel cobalt oxides for supercapacitors

    Science.gov (United States)

    Chang, Jie; Sun, Jing; Xu, Chaohe; Xu, Huan; Gao, Lian

    2012-10-01

    Nickel cobalt oxides with various Ni/Co ratios were synthesized using a facile template-free approach for electrochemical supercapacitors. The texture and morphology of the nanocomposites were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller analysis (BET). The results show that a hierarchical porous structure assembled from nanoflakes with a thickness of ~10 nm was obtained, and the ratio of nickel to cobalt in the nanocomposites was very close to the precursors. Cyclic voltammetry (CV) and galvanostatic charge and discharge tests were carried out to study the electrochemical performance. Both nickel cobalt oxides (Ni-Co-O-1 with Ni : Co = 1, Ni-Co-O-2 with Ni : Co = 2) outperform pure NiO and Co3O4. The Ni-Co-O-1 and Ni-Co-O-2 possess high specific capacities of 778.2 and 867.3 F g-1 at 1 A g-1 and capacitance retentions of 84.1% and 92.3% at 10 A g-1, respectively. After full activation, the Ni-Co-O-1 and Ni-Co-O-2 could achieve a maximum value of 971 and 1550 F g-1 and remain at ~907 and ~1450 F g-1 at 4 A g-1, respectively. Also, the nickel cobalt oxides show high capacity retention when fast charging.Nickel cobalt oxides with various Ni/Co ratios were synthesized using a facile template-free approach for electrochemical supercapacitors. The texture and morphology of the nanocomposites were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller analysis (BET). The results show that a hierarchical porous structure assembled from nanoflakes with a thickness of ~10 nm was obtained, and the ratio of nickel to cobalt in the nanocomposites was very close to the precursors. Cyclic voltammetry (CV) and galvanostatic charge and discharge tests were carried out to study the electrochemical performance. Both nickel cobalt oxides (Ni-Co-O-1 with Ni : Co = 1, Ni-Co-O-2 with Ni

  3. Nickel Oxide and Nickel Co-doped Graphitic Carbon Nitride Nanocomposites and its Octylphenol Sensing Application

    KAUST Repository

    Gong, Wanyun; Zou, Jing; Zhang, Sheng; Zhou, Xin; Jiang, Jizhou

    2015-01-01

    Nickel oxide and nickel co-doped graphitic carbon nitride (NiO-Ni-GCN) nanocomposites were successfully prepared by thermal treatment of melamine and NiCl2 6H2O. NiO-Ni-GCN nanocomposites showed superior electrochemical catalytic activity for the oxidation of octylphenol to pure GCN. A detection method of octylphenol in environmental water samples was developed based at NiO-Ni-GCN nanocomposites modified electrode under infrared light irradiation. Differential pulse voltammetry was used as the analytic technique of octylphenol, exhibiting stable and specific concentration-dependent oxidation signal in the presence of octylphenol in the range of 10nM to 1μM and 1μM to 50μM, with a detection limit of 3.3nM (3S/N). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Nickel Oxide and Nickel Co-doped Graphitic Carbon Nitride Nanocomposites and its Octylphenol Sensing Application

    KAUST Repository

    Gong, Wanyun

    2015-11-16

    Nickel oxide and nickel co-doped graphitic carbon nitride (NiO-Ni-GCN) nanocomposites were successfully prepared by thermal treatment of melamine and NiCl2 6H2O. NiO-Ni-GCN nanocomposites showed superior electrochemical catalytic activity for the oxidation of octylphenol to pure GCN. A detection method of octylphenol in environmental water samples was developed based at NiO-Ni-GCN nanocomposites modified electrode under infrared light irradiation. Differential pulse voltammetry was used as the analytic technique of octylphenol, exhibiting stable and specific concentration-dependent oxidation signal in the presence of octylphenol in the range of 10nM to 1μM and 1μM to 50μM, with a detection limit of 3.3nM (3S/N). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Early stages of oxidation of ion-implanted nickel at high temperature

    International Nuclear Information System (INIS)

    Peide, Z.; Grant, W.A.; Procter, R.P.M.

    1981-01-01

    The early stages of oxidation of nickel implanted with nickel, chromium, or lithium ions in oxygen at 1100 0 C have been studied using various electron-optical techniques. The unimplanted metal develops initially a fine-grained, convoluted scale having a ridged, cellular structure. Subsequently, the oxide grains increase in size significantly and oxidation becomes predominantly controlled by diffusion of Ni /sup 2+/ ions across a compact, columnar scale. Implantation of the surface with nickel ions has no significant effect on the initial oxidation behavior. However, after implantation with chromium or lithium ions, the development of the NiO scale is, in the early stages of oxidation, suppressed by formation of NiCr 2 O 4 or LiO 2 nodules, respectively. Subsequently, the implanted species are incorporated into the steady-state NiO scale where they dope the oxide and thus influence the diffusion rate of Ni /sup 2+/ ions through it. As would be predicted, the steady-state oxidation rate of chromium-implanted nickel is increased while that of lithium- implanted nickel is decreased compared with that of the unimplanted metal

  6. NiCo2O4 surface coating Li[Ni0.03Mn1.97]O4 micro-/nano- spheres as cathode material for high-performance lithium ion battery

    Science.gov (United States)

    Ye, Pan; Dong, Hui; Xu, Yunlong; Zhao, Chongjun; Liu, Dong

    2018-01-01

    Here we report a novel transitional metal oxide (NiCo2O4) coated Li[Ni0.03Mn1.97]O4 micro-/nano- spheres as high-performance Li-ion battery cathode material. A thin layer of ∼10 nm NiCo2O4 was formed by simple wet-chemistry approach adjacent to the surface of Li[Ni0.03Mn1.97]O4 micro-/nano- spheres, leading to significantly enhanced battery electrochemical performance. The optimized sample(1 wt%) not only delivers excellent discharge capacity and cycling stability improvement at both room temperature and elevated temperatures, but also effectively prevents Mn dissolution while retaining its coating structure intact according to XRF and TEM results. The CV and EIS break-down analysis indicated a much faster electrochemical reaction kinetics, more reversible electrode process and greatly reduced charge transfer and Warburg resistance, clearly illustrating the dual role of NiCo2O4 coating to boost electron transport and Li+ diffusion, and alleviation of manganese dissolving. This approach may render as an efficient technique to realize high-performance lithium ion battery cathode material.

  7. Pulsed laser deposition of {CeO_2} and {Ce_{1-x}M_xO_2} (M = La, Zr): Application to insulating barrier in cuprate heterostructures

    Science.gov (United States)

    Berger, S.; Contour, J.-P.; Drouet, M.; Durand, O.; Khodan, A.; Michel, D.; Régi, F.-X.

    1998-03-01

    SrTiO_3 had been often tentatively used as an insulating barrier for HT superconductor/insulator heterostructures. Unfortunately, the deposition of SrTiO_3 on the YBa_2Cu_3O_7 inverse interface results in a poor epitaxial regrowth producing a high roughness dislocated titanate layer. Taking into account the good matching with YBa_2Cu_3O_7 and LaAlO_3, CeO_2 and Ce_{1-x}M_xO_2 (M = La, Zr), epitaxial layers were grown by pulsed laser deposition on LaAlO_3 substrates and introduced into YBa_2Cu_3O_7 based heterostructures as insulating barrier. After adjusting the growth parameters from RHEED oscillations, epitaxial growth is achieved, the oxide crystal axes being rotated by 45^circ from those of the substrate. The surface roughness of 250 nm thick films is very low with a rms value lower than 0.5 nm over 1;μ m^2. The YBa_2Cu_3O_7 layers of a YBa_2Cu_3O_7/CeO_2 /YBa_2Cu_3O_7 heterostructures grown using these optimized parameters show an independent resistive transition, when the thickness is larger than 25 nm, respectively at T_c_1 = 89.6;K and T_c_2 = 91.4;{K}. SrTiO3 est souvent utilisé comme barrière isolante dans des hétérostructures SIS de cuprates supraconducteurs, cependant les défauts générés lors de la croissance de ce titanate sur l'interface inverse de YBa2Cu3O7 conduisent à un matériau dont la qualité cristalline et les propriétés physiques sont médiocres. L'oxyde de cérium CeO2 est également une barrière isolante potentielle intéressante pour ces structures SIS basées sur YBa2Cu3O7 car cet oxyde cubique (a = 0,5411 nm, asqrt{2}/2 = 0,3825 nm) qui est peu désaccordé par rapport au plan ab du cuprate (Δ a/a = - 0,18 %, Δ b/a = 1,6 %) présente de plus un coefficient de dilatation thermique (10,6 × 10^{-6 circ}C^{-1}) très voisin de celui de YBa2Cu3O7 (13 × 10^{-6 circ}C^{-1}). Nous avons donc étudié l'épitaxie de CeO2 et des oxydes de type Ce{1-x}MxO2 (M = La, Zr) en ablation laser pulsée afin de définir des conditions de

  8. Ni nanoparticles decorated onto graphene oxide with SiO2 as interlayer for high performance on histidine-rich protein separation

    Science.gov (United States)

    Yang, Xiaodan; Zhang, Min; Zheng, Jing; Li, Weizhen; Gan, Wenjun; Xu, Jingli; Hayat, Tasawar; Alharbi, Njud S.; Yang, Fan

    2018-05-01

    Sandwich-like structure of graphene oxide (GO) @SiO2@C-Ni nanosheets were prepared by combining an extended stöber method with subsequent carbonization treatment, in which polydopamine was used as reducing agent and carbon source. Firstly, the GO nanosheets were covered with SiO2 interlayer and finally coated with a outer shell of nickel ion doped polydopamine (PDA-Ni2+) with an extended stöber method. Followed by a carbonization to produce the GO@SiO2@C-Ni sheets with metallic nickel nanoparticles embedded in PDA-derived thin graphic carbon layer. Notably, silica interlayer played a vital role in the formation of such GO@SiO2@C-Ni sheets. Without the protection of SiO2, the hydrophobic graphene@C-Ni composites were obtained instead. While with silica layer as the spacer, the obtained hydrophilic GO@SiO2@C-Ni composites were not only well dispersed in the solution, but also can be adjusted in terms of the size and density of Ni nanoparticles (NPs) on surface by changing the calcination temperature or the molar ratio between dopamine and nickel salt. Furthermore, nickel nanoparticles decorated on GO@SiO2 sheets were employed to enrich His-rich proteins (BHb and BSA) via specific metal affinity force between polyhistidine groups and nickel nanoparticles.

  9. High rate performances of the cathode material LiNi1/3Co1/3Mn1/3O2 synthesized using low temperature hydroxide precipitation

    International Nuclear Information System (INIS)

    Cheng, Cuixia; Tan, Long; Liu, Haowen; Huang, Xintang

    2011-01-01

    Graphical abstract: A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize a cathode material LiNi 1/3 Co 1/3 Mn 1/3 O 2 . The charge-discharge tests were performed at 1000 mA g -1 between 2.5 and 4.5 V and the discharge capacity is about 160 mAh g -1 . The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 o C show the best electrochemical performance. Highlights: → A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize a novel cathode material LiNi 1/3 Co 1/3 Mn 1/3 O 2 . → The charge-discharge tests were performed at higher current as 5 C between 2.5 and 4.5 V. → The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 o C show the best electrochemical performance. -- Abstract: A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize the cathode material LiNi 1/3 Co 1/3 Mn 1/3 O 2 . The crystal structure and morphology of the prepared powder have been characterized by X-ray diffraction and Scan electron microscope, respectively. The charge-discharge tests were performed between 2.5 and 4.5 V. The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 o C show the best electrochemical performance and the initial discharge capacity is about 160 mAh g -1 at 5 C. Powder X-ray diffraction and Scan electron microscope results reveal that the excellent electrochemical performances should be ascribed to the lower precursor reaction temperature, the lower degree of cation mixing and analogous spherical small particles, which can improve the transfer of Li ions and electrons. All these results indicate that this material has potential application in lithium-ion batteries.

  10. Electronically Conductive Sb-doped SnO_2 Nanoparticles Coated LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 Cathode Material with Enhanced Electrochemical Properties for Li-ion Batteries

    International Nuclear Information System (INIS)

    He, Xiaoshu; Du, Chunyu; Shen, Bin; Chen, Cheng; Xu, Xing; Wang, Yajing; Zuo, Pengjian; Ma, Yulin; Cheng, Xinqun; Yin, Geping

    2017-01-01

    Highlights: • Conductive Sb-doped SnO_2 (ATO) is coated on LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 material. • The wet chemical process leads to homogeneous ATO coating layer. • The coated sample exhibits excellent rate capability and cyclic stability. • The capacity retention after 200 cycles at 60 °C increases by 20.81%. • The ATO coating restrains the cation disordering and SEI growth during cycling. - Abstract: The LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 (NCA) cathode material is modified by electronically conductive antimony-doped tin oxide (ATO) nanoparticles via a facile wet chemical process. As observed by scanning and transmission electron microscopy, the ATO nanoparticles are homogeneously coated on the surface of NCA material. Thus-obtained ATO-coated NCA (ATO-NCA) material delivers a high discharge capacity of 145 mAh g"−"1 at the current rate of 5C, which is significantly higher than that of pristine NCA material (135 mAh g"−"1). Moreover, the capacity retention of ATO-NCA material is 91.70% after 200 cycles at the current rate of 1C and 60 °C. In contrast, the pristine NCA only maintains 70.89% of its initial capacity after the same cycles. The substantially improved cyclability and rate capability are mainly attributed to the ATO coating layer, which can not only enhance the electron transport but also effectively restrain the side reactions between the NCA material and the electrolyte. More specifically, X-ray diffraction and photoelectron spectroscopy reveal that the ATO coating layer can restrain the Li"+/Ni"2"+ disordering and the growth of SEI layer of NCA material, which are responsible for the improved cycling stability, especially at elevated temperatures.

  11. Nitric oxide and bcl-2 mediated the apoptosis induced by nickel(II) in human T hybridoma cells

    International Nuclear Information System (INIS)

    Guan Fuqin; Zhang Dongmei; Wang Xinchang; Chen Junhui

    2007-01-01

    Although effects of nickel(II) on the immune system have long been recognized, little is known about the effects of nickel(II) on the induction of apoptosis and related signaling events in T cells. In the present study, we investigated the roles and signaling pathways of nickel(II) in the induction of apoptosis in a human T cell line jurkat. The results showed that the cytotoxic effects of Ni involved significant morphological changes and chromosomal condensation (Hoechst 33258 staining). Analyses of hypodiploid cells and FITC-Annexin V and PI double staining showed significant increase of apoptosis in jurkat cells 6, 12 and 24 h after nickel(II) treatment. Flow cytometry analysis also revealed that the loss of mitochondrial membrane potential (MMP) occurred concomitantly with the onset of NiCl 2 -induced apoptosis. Induction of apoptotic cell death by nickel was mediated by reduction of bcl-2 expression. Furthermore, nickel stimulated the generation of nitric oxide (NO). These results suggest that nickel(II) chloride induces jurkat cells apoptosis via nitric oxide generation, mitochondrial depolarization and bcl-2 suppression

  12. A versatile single molecular precursor for the synthesis of layered oxide cathode materials for Li-ion batteries.

    Science.gov (United States)

    Li, Maofan; Liu, Jiajie; Liu, Tongchao; Zhang, Mingjian; Pan, Feng

    2018-02-01

    A carbonyl-bridged single molecular precursor LiTM(acac) 3 [transition metal (TM) = cobalt/manganese/nickel (Co/Mn/Ni), acac = acetylacetone], featuring a one-dimensional chain structure, was designed and applied to achieve the layered oxide cathode materials: LiTMO 2 (TM = Ni/Mn/Co, NMC). As examples, layered oxides, primary LiCoO 2 , binary LiNi 0.8 Co 0.2 O 2 and ternary LiNi 0.5 Mn 0.3 Co 0.2 O 2 were successfully prepared to be used as cathode materials. When they are applied to lithium-ion batteries (LIBs), all exhibit good electrochemical performance because of their unique morphology and great uniformity of element distribution. This versatile precursor is predicted to accommodate many other metal cations, such as aluminum (Al 3+ ), iron (Fe 2+ ), and sodium (Na + ), because of the flexibility of organic ligand, which not only facilitates the doping-modification of the NMC system, but also enables synthesis of Na-ion layered oxides. This opens a new direction of research for the synthesis of high-performance layered oxide cathode materials for LIBs.

  13. Post mortem analysis of fatigue mechanisms in LiNi0.8Co0.15Al0.05O2 - LiNi0.5Co0.2Mn0.3O2 - LiMn2O4/graphite lithium ion batteries

    Science.gov (United States)

    Lang, Michael; Darma, Mariyam Susana Dewi; Kleiner, Karin; Riekehr, Lars; Mereacre, Liuda; Ávila Pérez, Marta; Liebau, Verena; Ehrenberg, Helmut

    2016-09-01

    The fatigue of commercial lithium ion batteries after long-term cycling at two different temperatures and cycling rates is investigated. The cells are opened after cycling and post-mortem analysis are conducted. Two main contributions to the capacity loss of the batteries are revealed. The loss of active lithium leads to a relative shift between anodes and cathodes potentials. A growth of the solid electrolyte interface (SEI) on the anode is determined as well as the formation of lithium fluoride species as an electrolyte decomposition product. Those effects are reinforced by increasing cycling rates from 1C/2C (charge/discharge) to 2C/3C as well as by increasing cycling temperatures from 25 °C to 40 °C. The other contribution to the capacity loss originates from a fatigue of the blended cathodes consisting of LiNi0.5Co0.2Mn0.3O2 (NCM), LiNi0.8Co0.15Al0.05O2 (NCA) and LiMn2O4 (LMO). Phase-specific capacity losses and fatigue mechanisms are identified. The layered oxides tend to form microcracks and reveal changes of the surface structure leading to a worsening of the lithium kinetics. The cathode exhibits a loss of manganese at 40 °C cycling temperature. Cycling at 40 °C instead of 25 °C has the major impact on cathodes capacity loss, while cycling at 2C/3C rates barely influences it.

  14. Nickel oxide/hydroxide nanoplatelets synthesized by chemical precipitation for electrochemical capacitors

    International Nuclear Information System (INIS)

    Wu, M.-S.; Hsieh, H.-H.

    2008-01-01

    Nickel hydroxide powder prepared by directly chemical precipitation method at room temperature has a nanoplatelet-like morphology and could be converted into nickel oxide at annealing temperature higher than 300 deg. C, confirmed by the thermal gravimetric analysis and X-ray diffraction. Annealing temperature influences significantly both the electrical conductivity and the specific surface area of nickel oxide/hydroxide powder, and consequently determines the capacitor behavior. Electrochemical capacitive behavior of the synthesized nickel hydroxide/oxide film is investigated by cyclic voltammetry and electrochemical impedance spectroscope methods. After 300 deg. C annealing, the highest specific capacitance of 108 F g -1 is obtained at scan rate of 10 mV s -1 . When annealing temperature is lower than 300 deg. C, the electrical conductivity of nickel hydroxide dominates primarily the capacitive behavior. When annealing temperature is higher than 300 deg. C, both electrical conductivity and specific surface area of the nickel oxide dominate the capacitive behavior

  15. Layered oxides-LiNi1/3Co1/3Mn1/3O2 as anode electrode for symmetric rechargeable lithium-ion batteries

    Science.gov (United States)

    Wang, Yuesheng; Feng, Zimin; Yang, Shi-Ze; Gagnon, Catherine; Gariépy, Vincent; Laul, Dharminder; Zhu, Wen; Veillette, René; Trudeau, Michel L.; Guerfi, Abdelbast; Zaghib, Karim

    2018-02-01

    High-performance and long-cycling rechargeable lithium-ion batteries have been in steadily increasing demand for the past decades. Nevertheless, the two dominant anodes at the moment, graphite and L4T5O12, suffer from a safety issue of lithium plating (operating voltage at ∼ 0.1 V vs. Li+/Li) and low capacity (175 mAh/g), respectively. Here, we report LiNi1/3Co1/3Mn1/3O2 as an alternative anode material which has a working voltage of ∼1.1 V and a capacity as high as 330 mAh/g at the current rate of C/15. Symmetric cells with both electrodes containing LiNi1/3Co1/3Mn1/3O2 can deliver average discharge voltage of 2.2 V. In-situ XRD, HRTEM and first principles calculations indicate that the reaction mechanism of a LiNi1/3Co1/3Mn1/3O2 anode is comprised mainly of conversion. Both the fundamental understanding and practical demonstrations suggest that LiNi1/3Co1/3Mn1/3O2 is a promising negative electrode material for lithium-ion batteries.

  16. 76 FR 47996 - Cobalt Lithium Manganese Nickel Oxide; Significant New Use Rule

    Science.gov (United States)

    2011-08-08

    ... Safety and Health Administration (OSHA) Permissible Exposure Level (PEL) of 0.1 mg/m\\3\\ for nickel. The... 2070-AB27 Cobalt Lithium Manganese Nickel Oxide; Significant New Use Rule AGENCY: Environmental... lithium manganese nickel oxide (CAS No. 182442-95-1), which was the subject of premanufacture notice (PMN...

  17. High Temperature Oxidation of Nickel-based Cermet Coatings Composed of Al2O3 and TiO2 Nanosized Particles

    Science.gov (United States)

    Farrokhzad, M. A.; Khan, T. I.

    2014-09-01

    New technological challenges in oil production require materials that can resist high temperature oxidation. In-Situ Combustion (ISC) oil production technique is a new method that uses injection of air and ignition techniques to reduce the viscosity of bitumen in a reservoir and as a result crude bitumen can be produced and extracted from the reservoir. During the in-situ combustion process, production pipes and other mechanical components can be exposed to air-like gaseous environments at extreme temperatures as high as 700 °C. To protect or reduce the surface degradation of pipes and mechanical components used in in-situ combustion, the use of nickel-based ceramic-metallic (cermet) coating produced by co-electrodeposition of nanosized Al2O3 and TiO2 have been suggested and earlier research on these coatings have shown promising oxidation resistance against atmospheric oxygen and combustion gases at elevated temperatures. Co-electrodeposition of nickel-based cermet coatings is a low-cost method that has the benefit of allowing both internal and external surfaces of pipes and components to be coated during a single electroplating process. Research has shown that the volume fraction of dispersed nanosized Al2O3 and TiO2 particles in the nickel matrix which affects the oxidation resistance of the coating can be controlled by the concentration of these particles in the electrolyte solution, as well as the applied current density during electrodeposition. This paper investigates the high temperature oxidation behaviour of novel nanostructured cermet coatings composed of two types of dispersed nanosized ceramic particles (Al2O3 and TiO2) in a nickel matrix and produced by coelectrodeposition technique as a function of the concentration of these particles in the electrolyte solution and applied current density. For this purpose, high temperature oxidation tests were conducted in dry air for 96 hours at 700 °C to obtain mass changes (per unit of area) at specific time

  18. One-pot hydrothermal synthesis of reduced graphene oxide/Ni(OH)2 films on nickel foam for high performance supercapacitors

    International Nuclear Information System (INIS)

    Min, Shudi; Zhao, Chongjun; Chen, Guorong; Qian, Xiuzhen

    2014-01-01

    Reduced graphene oxide (RGO) on nickel hydroxide (Ni(OH) 2 ) film was synthesized via a green and facile hydrothermal approach. In this process, graphene oxide (GO) was reduced by nickel foam (NF) while the nickel metal was oxidized to Ni(OH) 2 film simultaneously, which resulted in RGO on Ni(OH) 2 structure. The RGO/Ni(OH) 2 composite film was characterized using by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscope (FESEM). The electrochemical performances of the supercapacitor with the as-synthesized RGO/Ni(OH) 2 composite films as electrodes were evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectrometry (EIS) in 1 M KOH aqueous solution. Results indicated that the RGO/Ni(OH) 2 /NF composite electrodes exhibited superior capacitive performance with high capability (2500 mF cm −2 at a current density of 5 mA cm −2 , or 1667 F g −1 at 3.3 A g −1 ), compared with pure Ni(OH) 2 /NF (450 mF cm −2 at 5 mA cm −2 , 409 F g −1 at 3.3 A g −1 ) prepared under the identical conditions. Our study highlights the importance of anchoring RGO films on Ni(OH) 2 surface for maximizing the optimized utilization of electrochemically active Ni(OH) 2 and graphene for energy storage application in supercapacitors

  19. Study on the influences of reduction temperature on nickel-yttria-stabilized zirconia solid oxide fuel cell anode using nickel oxide-film electrode

    Science.gov (United States)

    Jiao, Zhenjun; Ueno, Ai; Suzuki, Yuji; Shikazono, Naoki

    2016-10-01

    In this study, the reduction processes of nickel oxide at different temperatures were investigated using nickel-film anode to study the influences of reduction temperature on the initial performances and stability of nickel-yttria-stabilized zirconia anode. Compared to conventional nickel-yttria-stabilized zirconia composite cermet anode, nickel-film anode has the advantage of direct observation at nickel-yttria-stabilized zirconia interface. The microstructural changes were characterized by scanning electron microscopy. The reduction process of nickel oxide is considered to be determined by the competition between the mechanisms of volume reduction in nickel oxide-nickel reaction and nickel sintering. Electrochemical impedance spectroscopy was applied to analyze the time variation of the nickel-film anode electrochemical characteristics. The anode performances and microstructural changes before and after 100 hours discharging and open circuit operations were analyzed. The degradation of nickel-film anode is considered to be determined by the co-effect between the nickel sintering and the change of nickel-yttria-stabilized zirconia interface bonding condition.

  20. Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

    OpenAIRE

    Lota, Katarzyna; Sierczynska, Agnieszka; Lota, Grzegorz

    2011-01-01

    In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘C in the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD). The morphology of the composite...

  1. Electrochemical Properties of the LiNi0.6Co0.2Mn0.2O2 Cathode Material Modified by Lithium Tungstate under High Voltage.

    Science.gov (United States)

    Fu, Jiale; Mu, Daobin; Wu, Borong; Bi, Jiaying; Cui, Hui; Yang, Hao; Wu, Hanfeng; Wu, Feng

    2018-05-31

    An amount (5 wt %) of lithium tungstate (Li 2 WO 4 ) as an additive significantly improves the cycle and rate performances of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode at the cutoff voltage of 4.6 V. The 5 wt % Li 2 WO 4 -mixed LiNi 0.6 Co 0.2 Mn 0.2 O 2 electrode delivers a reversible capacity of 199.2 mA h g -1 and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g -1 at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g -1 , respectively. It is shown that the structure of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode material is not affected by mixing Li 2 WO 4 . The introduced Li 2 WO 4 effectively restrains the LiPF 6 and carbonate solvent decomposition by consuming PF 5 at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

  2. Solid-state interaction between nickel and YBa/sub 2/Cu/sub 3/O/sub x/

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, B; Parent, L; Moreau, C

    1989-01-01

    As part of a search for suitable metals for use in composite cables made up of high-temperature superconductors in a metallic matrix, the solid-state reaction between nickel and YBa/sub 2/Cu/sub 3/O/sub x/ was studied. Green compacts of YBa/sub 2/Cu/sub 3/O/sub x/ were hot isostatically pressed (HIPed) in nickel. The microstructure, density and nature of phases present in HIPed parts were characterized. Resistivity measurements indicated that HIPed parts are not superconducting owing to the loss of oxygen and required an annealing step in oxygen for restoring superconductivity. The diffusion of nickel into YBa/sub 2/Cu/sub 3/O/sub x/ as well as the diffusion of Ba, Cu and Y into nickel was very limited. However, a thin interaction zone consisting of a nickel-rich oxide compound was formed at the Ni-YBa/sub 2/Cu/sub 3/O/sub x/ interface. The presence of such an interaction zone could have a detrimental effect on the thermal stabilization of Ni-YBa/sub 2/Cu/sub 3/O/sub x/ composite wires. 7 refs., 6 figs., 1 tab.

  3. Mechanisms of nickel toxicity in microorganisms

    Science.gov (United States)

    Macomber, Lee

    2014-01-01

    Summary Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological concern. To date, the mechanisms of nickel toxicity in microorganisms and higher eukaryotes are poorly understood. In this review, we summarize nickel homeostasis processes used by microorganisms and highlight in vivo and in vitro effects of exposure to elevated concentrations of nickel. On the basis of this evidence we propose four mechanisms of nickel toxicity: 1) nickel replaces the essential metal of metalloproteins, 2) nickel binds to catalytic residues of non-metalloenzymes; 3) nickel binds outside the catalytic site of an enzyme to inhibit allosterically, and 4) nickel indirectly causes oxidative stress. PMID:21799955

  4. Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

    Directory of Open Access Journals (Sweden)

    Katarzyna Lota

    2011-01-01

    Full Text Available In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘C in the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD. The morphology of the composites was observed by SEM. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied in addition to the properties of electrode consisting of separate active carbon and nickel oxide only. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy. The composites were tested in 6 M KOH aqueous electrolyte using two- and three-electrode Swagelok systems. The results showed that adding only a few percent of nickel oxide to active carbon provided the highest value of capacity. It is the confirmation of the fact that such an amount of nickel oxide is optimal to take advantage of both components of the composite, which additionally can be a good solution as a negative electrode in asymmetric configuration of electrode materials in an electrochemical capacitor.

  5. (PO_4)"3"− polyanions doped LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2: An ultrafast-rate, long-life and high-voltage cathode material for Li-ion rechargeable batteries

    International Nuclear Information System (INIS)

    Cong, Lina; Zhao, Qin; Wang, Zhao; Zhang, Yuhang; Wu, Xinglong; Zhang, Jingping; Wang, Rongshun; Xie, Haiming; Sun, Liqun

    2016-01-01

    Highlights: • LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 layered structure is doped with (PO_4)"3"− polyanions. • Results confirm that (PO_4)"3"− influences MO_6 octahedral environment in LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 lattice. • Charge–discharge properties are investigated under high voltage battery operation. • Cycling and rate performance of the doped materials is markedly enhanced. • Pre-cycling treatment inhibits microcracks at the grain boundaries at 4.7–2.8 V. - Abstract: Layered compounds LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 have recently received much attention as they have been regarded as a promising cathode materials for industrial application. However, its fast energy density decay and poor rate performance which originate from structure disruption especially at high rate and high cut-off voltage limit its large-scale application. Here, a novel designed concept and facile method were firstly used to fabricate (PO_4)"3"− polyanions doped layered LiNi_1_/_3Co_1_/_3Mn_1_/_3O_2 (LNMC-(PO_4) _0_._0_1_5-O_1_._9_4) structure, which could offer more stable high-voltage cycling performance and high rate capability. We attribute this improved performance to the robust P_t_e_t-O covalence, which will stabilize the oxygen close-packed structure during repeated cycling. Moreover, our stepwise pre-cycling treatments could effectively restrain the formation of micro-cracks and non-crystallization defects, and significantly improve cyclic durability with high charge voltage of 4.7V. The LNMC-(PO_4) _0_._0_1_5-O_1_._9_4 electrode can still delivers capacity retention of 81% after 200 cycles at a current density of 300mA g"−"1. The preliminary results reported here manifest that this novel-designed LNMC-(PO_4) _0_._0_1_5-O_1_._9_4 material represents an attractive alternative to ultrafast-rate, long-life and high-voltage electrode material for lithium ion batteries.

  6. Combined use of EPR and 23Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt-nickel-manganese layers of P3-NayCo1-2xNixMnxO2.

    Science.gov (United States)

    Kalapsazova, M; Ivanova, S; Kukeva, R; Simova, S; Wegner, S; Zhecheva, E; Stoyanova, R

    2017-10-11

    Knowledge on the formation of mixed transition metal layers on lithium and sodium transition metal oxides, Li/Na(Co,Ni,Mn,)O 2 , determines the ability to control their electrochemical properties as electrode materials in alkaline ion batteries. Taking this into account, herein we combine the EPR and 23 Na MAS NMR spectroscopic techniques to gain insights into the structural peculiarities of the mixed cobalt-nickel-manganese layers of Na y Co 1-2x Ni x Mn x O 2 with a three-layer stacking (P3-type) structure. Two types of compositions are examined where diamagnetic Co 3+ and paramagnetic Ni 3+ and Mn 4+ are stabilized: Na 2/3 Co 1/3 Ni 1/3 Mn 1/3 O 2 and Na 1/2 Ni 1/2 Mn 1/2 O 2 . EPR spectroscopy operating in the X- and Q-band region is applied with an aim to improve the spectra resolution and, on the other hand, to provide straightforward information on the coordination of the transition metal ions inside the layers. The analysis of EPR spectra is based on the reference for the Mn 4+ and Ni 2+ ions occurring simultaneously in oxides with two layer stacking, P2-Na 2/3 Ni 1/3 Mn 2/3 O 2 . Complementary to EPR, 23 Na MAS NMR spectroscopy at high spinning rates is undertaken to assess the local structure of the Na nucleus in the layered P3-Na y Co 1-2x Ni x Mn x O 2 oxides. All results are discussed taking into account the EPR and NMR data for the well-known lithium analogues O3-LiCo 1/3 Ni 1/3 Mn 1/3 O 2 and O3-LiNi 1/2 Mn 1/2 O 2 . Finally, the structure peculiarities of the transition metal layers extracted from the EPR and NMR methods are demonstrated by electrochemical intercalation of Li + ions into P3-Na y Co 1-2x Ni x Mn x O 2 .

  7. Properties of Copper Doped Neodymium Nickelate Oxide as Cathode Material for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Lee Kyoung-Jin

    2016-06-01

    Full Text Available Mixed ionic and electronic conducting K2NiF4-type oxide, Nd2Ni1-xCuxO4+δ (x=0~1 powders were synthesized by solid state reaction technique and solid oxide fuel cells consisting of a Nd2Ni1-xCuxO4+δ cathode, a Ni-YSZ anode and ScSZ as an electrolyte were fabricated. The effect of copper substitution for nickel on the electrical and electrochemical properties was examined. Small amount of copper doping (x=0.2 resulted in the increased electrical conductivity and decreased polarization resistance. It appears that this phenomenon was associated with the high mean valence of nickel and copper and the resulting excess oxygen (δ. It was found that power densities of the cell with the Nd2Ni1-xCuxO4+δ (x=0.1 and 0.2 cathode were higher than that of the cell with the Nd2NiO4+δ cathode.

  8. Effect of Cu Doping on the Structural and Electrochemical Performance of LiNi1/3Co1/3Mn1/3O2 Cathode Materials

    Science.gov (United States)

    Yang, Li; Ren, Fengzhagn; Feng, Qigao; Xu, Guangri; Li, Xiaobo; Li, Yuanchao; Zhao, Erqing; Ma, Jignjign; Fan, Shumin

    2018-04-01

    The structural and electrochemical performance of Cu-doped, Li[Ni1/3-xCo1/3 Mn1/3Cux]O2 (x = 0-0.1) cathode materials obtained by means of the sol-gel method are discussed; we used critic acid as gels and spent mixed batteries as the raw materials. The effects of the sintering time, sintering temperature, and Cu doping ratio on the phase structure, morphology, and element composition and the behavior in a galvanostatical charge/discharge test have been systemically studied. The results show that the Cu-doped material exhibits better galvanostatic charge/discharge cycling performance. At 0.2 C, its original discharge specific capacity is 180.4 mAh g-1 and its Coulomb efficiency is 90.3%. The Cu-doped material demonstrate an outstanding specific capacity at 0.2 C, 0.5 C, and 2.0 C. In comparison with the original capacities of 178 mAh g-1, 159.5 mAh g-1, and 119.4 mAh g-1, the discharge capacity after 50 cycles is 160.8 mAh g-1, 143.4 mAh g-1, and 90.1 mAh g-1, respectively. This obvious improvement relative to bare Li[Ni1/3Co1/3Mn1/3]O2 cathode materials arises from an enlarged Li layer spacing and a reduced degree of cation mixing. Therefore, Cu-doped cathode materials have obvious advantages in the field of lithium-ion batteries and their applications.

  9. Oxidation resistance of nickel alloys at high temperature

    International Nuclear Information System (INIS)

    Tyuvin, Yu.D.; Rogel'berg, I.L.; Ryabkina, M.M.; Plakushchaya, A.F.

    1977-01-01

    The heat resistance properties of nickel alloys Ni-Cr-Si, Ni-Si-Al, Ni-Si-Mn and Ni-Al-Mn have been studied by the weight method during oxidation in air at 1000 deg and 1200 deg C. It is demonstrated that manganese reduces the heat resistance properties of Ni-Si and Ni-Al alloys, whilst the addition of over 3% aluminium enhances the heat resistance properties of Ni-Si (over 1.5%) alloys. The maximum heat resistance properties are shown by Ni-Si-Al and Ni-Cr-Si alloys with over 2% Si. These alloys offer 3 to 4 times better oxidation resistance as compared with pure nickel at 1000 deg C and 10 times at 1200 deg C

  10. Ab initio Studies of O2 Adsorption on (110 Nickel-Rich Pentlandite (Fe4Ni5S8 Mineral Surface

    Directory of Open Access Journals (Sweden)

    Peace P. Mkhonto

    2015-10-01

    Full Text Available Ab initio density functional theory was used to investigate the adsorption of oxygen molecule on the nickel-rich pentlandite (110 surface, which is important for mineral extraction. The three most reactive adsorption sites: Fe-top, Ni-top, and fcc-hollow have been considered. Firstly, the non-adsorbed pentlandite surface reflects the Ni atoms relaxing inwards. Consequently, their electronic structure showed high Fe 3d-orbital contribution than the Ni 3d-orbitals at the EF (indicating that the Fe atoms are more reactive than Ni. Secondly, the O2-adsorbed surface predicted lowest adsorption energy for Fe-top (-1.902 eV, as a more spontaneous reaction is likely to occur than on fcc-hollow (-1.891 eV and Ni-top (-0.040 eV sites, suggesting Fe preferential oxidation. The density of states indicates that the O2 show prevalence of electrons in the πp* antibonding orbitals, and are reduced to zero states at the valence band on metal-bonded oxygen (O1. The πp* orbital is observed to reside just above the EF for Fe-top and fcc-hollow site, while on Ni-top is half-occupied for both metal-bonded oxygen (O1 and terminal oxygen (O2. Finally, the isosurface charge density difference showed electron (charge depletion on Ni/Fe metals and accumulation on the O2 molecule. Bader analysis indicated that the oxidized Fe and Ni atoms adopt more positive charge, while O2 on Fe-top atoms possesses more negative charge than on Ni-top, resulting with O1 possessing a smaller charge than O2 atom.

  11. Study of the high temperature oxidation of nickel; Contribution a l'etude de l'oxydation du nickel aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Berry, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-11-01

    The parabolic oxidation of nickel by oxygen and by air at atmospheric pressure has been studied in the temperature range 600 to 1400 C, in particular by thermogravimetric and micrographic techniques. The mechanism of the reaction has been determined; it has been shown in particular that the break in the Arrhenius plot of the kinetics, occurring at about 950 C, is the result of a stimulation of the diffusion across the nickel prot-oxide film above this temperature; this is the result of the presence of excess nickel vacancies in the film. A systematic study has also been made of the influence of the oxygen pressure P{sub O{sub 2}} (10{sup -2} torr {<=} P{sub O{sub 2}} {<=} 760 torr) on the parabolic oxidation of nickel between 800 and 1400 C. In the range 1000 to 1400 C, the activation energy of the process decreases monotonously from 57 to 34 kcal/mole as P{sub O{sub 2}} decreases from 760 to 1 torr. Furthermore, it has been shown that the parabolic oxidation constant is proportional to P{sub O{sub 2}}{sup 1/n} the value of n is not invariant however in the temperature range examined, but decreases from 6 to about 3 when the temperature increases from 900 to 1400 C. Finally, a study has been made of the oxidation of nickel in carbon dioxide at atmospheric pressure between 750 and 1400 C. The main reaction is Ni + CO{sub 2} {yields} NiO + CO, and corresponds, with a good approximation, to the reaction of the metal with the oxygen produced by the thermal dissociation of the CO{sub 2}. (author) [French] L'oxydation parabolique du nickel avec l'oxygene et l'air a la pression atmospherique a ete etudiee dans l'intervalle de temperatures 600-1400 C, surtout par voies thermogravimetrique et micrographique. Le mecanisme de la reaction a ete precise; en particulier, il a ete montre que la brisure de la courbe d'Arrhenius traduisant sa cinetique, qui se produit a 950 C environ, resulte d'une stimulation de la diffusion dans la pellicule de protoxyde de nickel au dessous de

  12. Synthesis and characterization of nickel oxide particulate annealed at different temperatures

    Science.gov (United States)

    Sharma, Khem Raj; Thakur, Shilpa; Negi, N. S.

    2018-04-01

    Nickel oxide has been synthesized by solution combustion technique. The nickel oxide ceramic was annealed at 600°C and 1000°C for 2 hours. Structural, electrical, dielectric and magnetic properties were analyzed which are strongly dependent upon the synthesis method. Structural properties were examined by X-ray diffractometer (XRD), which confirmed the purity and cubic phase of nickel oxide. XRD data reveals the increase in crystallite size and decrease in full width half maximum (FWHM) as the annealing temperature increases. Electrical conductivity is found to increase from 10-6 to 10-5 (Ω-1cm-1) after annealing. Dielectric constant is observed to increase from 26 to 175 when the annealing temperature is increased from 600°C to 1000°C. Low value of coercive field is found which shows weak ferromagnetic behavior of NiO. It is observed that all the properties of NiO particulate improve with increasing annealing temperature.

  13. Size-dependent magnetic properties of branchlike nickel oxide nanocrystals

    Directory of Open Access Journals (Sweden)

    Dan Liu

    2017-01-01

    Full Text Available Branchlike nickel oxide nanocrystals with narrow size distribution are obtained by a solution growth method. The size-dependent of magnetic properties of the nickel oxides were investigated. The results of magnetic characterization indicate that the NiO nanocrystals with size below 12.8 nm show very weak ferromagnetic state at room temperature due to the uncompensated spins. Both of the average blocking temperature (Tb and the irreversible temperature (Tirr increase with the increase of nanoparticle sizes, while both the remnant magnetization and the coercivity at 300 K increase with the decrease of the particle sizes. Moreover, the disappearance of two-magnon (2M band and redshift of one-phonon longitudinal (1LO and two-phonon LO in vibrational properties due to size reduction are observed. Compared to the one with the spherical morphological, it is also found that nano-structured nickel oxides with the branchlike morphology have larger remnant magnetization and the coercivity at 5 K due to their larger surface-to-volume ratio and greater degree of broken symmetry at the surface or the higher proportion of broken bonds.

  14. Freeze drying synthesis of LiNi0.5Mn0.5O2 cathode materials

    International Nuclear Information System (INIS)

    Shlyakhtin, O.A.; Yoon, Young Soo; Choi, Sun Hee; Oh, Young-Jei

    2004-01-01

    The influence of several processing conditions on the phase formation and electrochemical performance of LiNi 0.5 Mn 0.5 O 2 powders, obtained by freeze drying method, is studied. Thermal processing in pellets at maximum heating rate promotes better crystallographic ordering of hexagonal LiNi 0.5 Mn 0.5 O 2 and maximum capacity values irrespectively of chemical composition of the precursor. Instead, intense mechanical processing of precursors exerts considerable negative effect on the electrochemical performance. Cathode materials containing superstoichiometric amount of lithium (Li 1.3 Mn 0.5 Ni 0.5 O 2+δ ) demonstrate reversible capacity values up to 190 mAh/g between 2.5 and 4.6 V

  15. Synthesis and electrochemical properties of LiNi0.4Mn1.5Cr0.1O4 and Li4Ti5O12

    CSIR Research Space (South Africa)

    Liu, GQ

    2011-08-01

    Full Text Available Spinel compound LiNi0.4Mn1.5Cr0.1O4 (LNMCO) and Li4Ti5O12 (LTO) were synthesized by the sol-gel method and the solid-state method, respectively. The particle sizes of the products LiNi0.4Mn1.5Cr0.1O4 and Li4Ti5O12 were 0.5 to 2 um and 0.5 to 0.8 um...

  16. Monodispersed macroporous architecture of nickel-oxide film as an anode material for thin-film lithium-ion batteries

    International Nuclear Information System (INIS)

    Wu, Mao-Sung; Lin, Ya-Ping

    2011-01-01

    A nickel-oxide film with monodispersed open macropores was prepared on a stainless-steel substrate by electrophoretic deposition of a polystyrene-sphere monolayer followed by anodic electrodeposition of nickel oxy-hydroxide. The deposited films convert to cubic nickel oxide after annealing at 400 o C for 1 h. Galvanostatic charge and discharge results indicate that the nickel-oxide film with monodispersed open macropores is capable of delivering a higher capacity than the bare nickel-oxide film, especially in high-rate charge and discharge processes. The lithiation capacity of macroporous nickel oxide reaches 1620 mA h g -1 at 1 C current discharge and decreases to 990 mA h g -1 at 15 C current discharge. The presence of monodispersed open macropores in the nickel-oxide film might facilitate the electrolyte penetration, diffusion, and migration. Electrochemical reactions between nickel oxide and lithium ions are therefore markedly improved by this tailored film architecture.

  17. Kinetics of oxidation of nickel(II) aza macrocycles by ...

    Indian Academy of Sciences (India)

    The kinetics of the oxidation of nickel (II) hexaaza and nickel (II) pentaaza macrocycles by the peroxydisulphate anion, S2O8 2-, were studied in aqueous media. Effect of H on reaction rate was also studied. The rate increases with increase of S2OO8 2- concentration. Rates are almost independent of acid between H 4 ...

  18. Synthesis of LiNi0.65Co0.25Mn0.1O2 as cathode material for lithium-ion batteries by rheological phase method

    International Nuclear Information System (INIS)

    Cheng Cuixia; Tan Long; Hu Anzheng; Liu Haowen; Huang Xintang

    2010-01-01

    Research highlights: → In this paper, for the first time, rheological phase method, a simple and effective route, was applied to synthesis high capacity cathode material LiNi 0.65 Co 0.25 Mn 0.1 O 2 . → All of the results obtained by X-ray diffraction spectrometer, X-ray photoelectron spectrometer, charge-discharge tests and electrochemical impedance spectroscopy show that the rheological phase production have better properties than that of the report. - Abstract: Rheological phase (RP) method has been successfully applied to synthesize a promising cathode material LiNi 0.65 Co 0.25 Mn 0.1 O 2 . X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma and transmission electron microscope are used to investigate the structure, composition and morphology, respectively. XRD result shows that the as-prepared powder has a layered α-NaFeO 2 structure. XPS pattern reveals that the Ni ions have valences of 2+ and 3+, and the Co and Mn are 3+, 4+, respectively. The electrode consisting of the obtained powder presents the better electrochemical properties, which is attributed to the fewer amounts of Ni 2+ ions and the smaller particles. All the results suggest that the rheological phase method is a promising technique for the preparation of LiNi 0.65 Co 0.25 Mn 0.1 O 2 cathode material of lithium-ion batteries.

  19. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 - 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  20. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, R.W.; Muller, R.H.

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 {endash} 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  1. Nanoroses of nickel oxides: Synthesis, electron tomography study, and application in CO oxidation and energy storage

    KAUST Repository

    Fihri, Aziz; Sougrat, Rachid; Baby, Rakhi Raghavan; Rahal, Raed; Cha, Dong Kyu; Hedhili, Mohamed N.; Bouhrara, Mohamed; Alshareef, Husam N.; Polshettiwar, Vivek

    2012-01-01

    Nickel oxide and mixed-metal oxide structures were fabricated by using microwave irradiation in pure water. The nickel oxide self-assembled into unique rose-shaped nanostructures. These nickel oxide roses were studied by performing electron

  2. Mechanistic Insight in the Function of Phosphite Additives for Protection of LiNi0.5Co0.2Mn0.3O2 Cathode in High Voltage Li-Ion Cells.

    Science.gov (United States)

    He, Meinan; Su, Chi-Cheung; Peebles, Cameron; Feng, Zhenxing; Connell, Justin G; Liao, Chen; Wang, Yan; Shkrob, Ilya A; Zhang, Zhengcheng

    2016-05-11

    Triethlylphosphite (TEP) and tris(2,2,2-trifluoroethyl) phosphite (TTFP) have been evaluated as electrolyte additives for high-voltage Li-ion battery cells using a Ni-rich layered cathode material LiNi0.5Co0.2Mn0.3O2 (NCM523) and the conventional carbonate electrolyte. The repeated charge/discharge cycling for cells containing 1 wt % of these additives was performed using an NCM523/graphite full cell operated at the voltage window from 3.0-4.6 V. During the initial charge process, these additives decompose on the cathode surface at a lower oxidation potential than the baseline electrolyte. Impedance spectroscopy and post-test analyses indicate the formation of protective coatings by both additives on the cathode surface that prevent oxidative breakdown of the electrolyte. However, only TTFP containing cells demonstrate the improved capacity retention and Coulombic efficiency. For TEP, the protective coating is also formed, but low Li(+) ion mobility through the interphase layer results in inferior performance. These observations are rationalized through the inhibition of electrocatalytic centers present on the cathode surface and the formation of organophosphate deposits isolating the cathode surface from the electrolyte. The difference between the two phosphites clearly originates in the different properties of the resulting phosphate coatings, which may be in Li(+) ion conductivity through such materials.

  3. Preparation and application of PVDF-HFP composite polymer electrolytes in LiNi0.5Co0.2Mn0.3O2 lithium-polymer batteries

    International Nuclear Information System (INIS)

    Yang, Chun-Chen; Lian, Zuo-Yu; Lin, S.J.; Shih, Jeng-Ywan; Chen, Wei-Houng

    2014-01-01

    Graphical abstract: - Highlights: • PVDF-HFP/SBA15 membrane and NCM cathode material were prepared for Li ion battery. • SBA15 fillers can trap more liquid electrolytes to enhance the ionic conductivity. • Modified fillers with functional groups play a key role in reducing impedance. • LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer battery showed excellent electrochemical performance. - Abstract: This study reports the preparation of a composite polymer electrolyte for application in LiNi 0.5 Co 0.2 Mn 0.3 O 2 lithium-polymer batteries. Poly(vinylidiene fluoride-hexafluoropropylene) (denoted as PVDF-HFP) was used as the polymer host and mesoporous modified-silica fillers (denoted as m-SBA15) used as the solid plasticizer were added into the polymer matrix. The characteristic properties of the composite polymer membranes were examined using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and an AC impedance method. The discharge capacities of LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer batteries with a PE separator, pure PVDF-HFP polymer membrane, or a PVDF-HFP/10 wt.%m-SBA15 composite at 0.1 C were determined to be 155.5, 159.5, and 198.6 mAh g −1 , respectively. The LiNi 0.5 Co 0.2 Mn 0.3 O 2 polymer battery containing the PVDF-HFP/10 wt.%m-SBA15 composite achieved discharge capacities of 194, 170, 161, 150, 129, 115, and 87 mAh g −1 at 0.1, 0.2, 0.5, 1, 3, 5, and 10 C, respectively. The lithium-polymer battery demonstrated a high coulomb efficiency of ca. 99%. The PVDF-HFP/m-SBA15 composite membrane is a strong candidate for application in LiNi 0.5 Co 0.2 Mn 0.3 O 2 lithium-polymer batteries

  4. Ni/SiO2 Catalyst Prepared with Nickel Nitrate Precursor for Combination of CO2 Reforming and Partial Oxidation of Methane: Characterization and Deactivation Mechanism Investigation

    Directory of Open Access Journals (Sweden)

    Sufang He

    2015-01-01

    Full Text Available The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream.

  5. 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.

  6. Evolution of grain structure in nickel oxide scales

    International Nuclear Information System (INIS)

    Atkinson, H.V.

    1987-01-01

    In systems such as the oxidation of nickel, in which grain-boundary diffusion in the oxide can control the rate of oxidation, understanding of the factors governing the grain structure is of importance. High-purity mechanically polished polycrystalline nickel was oxidized at 700 0 C, 800 0 C, and 1000 0 C for times up to 20 hr in 1 atm O 2 . The scale microstructures were examined by parallel and transverse cross section transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Texture coefficients were found by x-ray diffraction (XRD). Each grain in the transverse section grain boundary networks was systematically analyzed for width parallel to the Ni-NiO interface and perpendicular length, for boundary radius of curvature and for number of sides. The variation of these parameters with depth in the scale was examined. In particular, grains were increasingly columnar (i.e., with ratio of grain length to width > 1) at higher temperatures and longer times. Columnar grain boundaries tended to be fairly static; the columnar grain width was less than the rate controlling grain size predicted from the oxidation rate. The mean boundary curvature per grain provided a guide to the tendency for grain growth, except in the region of the Ni-NiO interface, where the boundaries were thought to be pinned

  7. Effect of charge state and stoichiometry on the structure and reactivity of nickel oxide clusters with CO

    Science.gov (United States)

    Johnson, Grant E.; Reilly, Nelly M.; Castleman, A. W., Jr.

    2009-02-01

    The collision induced fragmentation and reactivity of cationic and anionic nickel oxide clusters with carbon monoxide were studied experimentally using guided-ion-beam mass spectrometry. Anionic clusters with a stoichiometry containing one more oxygen atom than nickel atom (NiO2-, Ni2O3-, Ni3O4- and Ni4O5-) were found to exhibit dominant products resulting from the transfer of a single oxygen atom to CO, suggesting the formation of CO2. Of these four species, Ni2O3- and Ni4O5- were observed to be the most reactive having oxygen transfer products accounting for approximately 5% and 10% of the total ion intensity at a maximum pressure of 15 mTorr of CO. Our findings, therefore, indicate that anionic nickel oxide clusters containing an even number of nickel atoms and an odd number of oxygen atoms are more reactive than those with an odd number of nickel atoms and an even number of oxygen atoms. The majority of cationic nickel oxides, in contrast to anionic species, reacted preferentially through the adsorption of CO onto the cluster accompanied by the loss of either molecular O2 or nickel oxide units. The adsorption of CO onto positively charged nickel oxides, therefore, is exothermic enough to break apart the gas-phase clusters. Collision induced dissociation experiments, employing inert xenon gas, were also conducted to gain insight into the structural properties of nickel oxide clusters. The fragmentation products were found to vary considerably with size and stoichiometry as well as ionic charge state. In general, cationic clusters favored the collisional loss of molecular O2 while anionic clusters fragmented through the loss of both atomic oxygen and nickel oxide units. Our results provide insight into the effect of ionic charge state on the structure of nickel oxide clusters. Furthermore, we establish how the size and stoichiometry of nickel oxide clusters influences their ability to oxidize CO, an important reaction for environmental pollution abatement.

  8. Adsorption and bio-sorption of nickel ions and reuse for 2-chlorophenol catalytic ozonation oxidation degradation from water

    International Nuclear Information System (INIS)

    Ma, Wei; Zong, Panpan; Cheng, Zihong; Wang, Baodong; Sun, Qi

    2014-01-01

    Highlights: • Biomass and fly ash which were widespread for adsorption of heavy metal ions. • Preparation of catalyst by saturated adsorbents for 2-chlorophenol ozone degradation. • This work demonstrated that the O 3 /catalyst process was an effective pathway. • The use of nickel ions, fly ash and sawdust to achieve the recycling utilization of resources. -- Abstract: This work explored the preparation of an effective and low-cost catalyst and investigated its catalytic capacity for 2-chlorophenol ozonation oxidation degradation in wastewater by using an ozone oxidation batch reactor. The catalyst was directly prepared by the reuse of fly ash and sawdust after saturated adsorption of nickel ions from wastewater, which was proposed as an efficient and economic approach. The obtained catalyst was characterized by TGA, BET, FTIR, XRD, and SEM, the results showed that fly ash as the basic framework has high specific surface area and the addition of sawdust as the porogen agent could improve the pore structure of the catalyst. The adsorption of nickel ions by fly ash and sawdust from aqueous solution was also investigated in this study. The results obtained from the experiments indicated that adsorption of nickel ions by fly ash and biomass sawdust could be well described by Langmuir isotherm model and pseudo second order kinetic model. The catalytic performance of catalyst was studied in terms of the effect of time, liquid–solid ratio and pH on 2-chlorophenol ozonation degradation. It was found that the catalyst could effectively improve the ozonation reaction rate at pH = 7 with a 2:1 liquid–solid ratio. The kinetic study demonstrated that the reaction followed the first order model, and the rate constant increased 267% (0.03–0.1 min −1 ) of 2-chlorophenol ozonation degradation with 5 mmol/L concentration at pH = 7.0 compared with ozonation alone

  9. Controlled synthesis of size-tunable nickel and nickel oxide nanoparticles using water-in-oil microemulsions

    International Nuclear Information System (INIS)

    Kumar, Ajeet; Saxena, Amit; Shankar, Ravi; Mozumdar, Subho; De, Arnab

    2013-01-01

    Industrial demands have generated a growing need to synthesize pure metal and metal–oxide nanoparticles of a desired size. We report a novel and convenient method for the synthesis of spherical, size tunable, well dispersed, stable nickel and nickel oxide nanoparticles by reduction of nickel nitrate at room temperature in a TX-100/n-hexanol/cyclohexane/water system by a reverse microemulsion route. We determined that reduction with alkaline sodium borohydrate in nitrogen atmosphere leads to the formation of nickel nanoparticles, while the use of hydrazine hydrate in aerobic conditions leads to the formation of nickel oxide nanoparticles. The influence of several reaction parameters on the size of nickel and nickel oxide nanoparticles were evaluated in detail. It was found that the size can be easily controlled either by changing the molar ratio of water to surfactant or by simply altering the concentration of the reducing agent. The morphology and structure of the nanoparticles were characterized by quasi-elastic light scattering (QELS), transmission electron microscopy (TEM), x-ray diffraction (XRD), electron diffraction analysis (EDA) and energy dispersive x-ray (EDX) spectroscopy. The results show that synthesized nanoparticles are of high purity and have an average size distribution of 5–100 nm. The nanoparticles prepared by our simple methodology have been successfully used for catalyzing various chemical reactions. (paper)

  10. Process for electroforming nickel containing dispersed thorium oxide particles therein

    International Nuclear Information System (INIS)

    Malone, G.A.

    1975-01-01

    Nickel electroforming is effected by passing a direct current through a bath containing a dissolved nickel salt or a mixture of such salts, such as those present in sulfamate or Watts baths, and finely divided sol-derived thorium oxide particles of 75 to 300 angstroms, preferably 100 to 200 angstroms diameters therein, at a pH in the range of 0.4 to 1.9, preferably 0.8 to 1.3. The nickel so deposited, as on a pre-shaped stainless steel cathode, may be produced in desired shape and may be removed from the cathode and upon removal, without additional working, possesses desirable engineering properties at elevated temperatures, e.g., 1,500 to 2,200 0 F. Although the material produced is of improved high temperature stability, hardness, and ductility, compared with nickel alone, it is still ductile at room temperature and has properties equivalent or superior to nickel at room temperatures up to 1,500 0 F. Further improvements in mechanical properties of the material may be obtained by working. Also disclosed are electrodeposition baths, methods for their manufacture, and products resulting from the electrodeposition process. (U.S.)

  11. Intraplate mantle oxidation by volatile-rich silicic magmas

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Audrey M.; Médard, Etienne; Righter, Kevin; Lanzirotti, Antonio

    2017-11-01

    The upper subcontinental lithospheric mantle below the French Massif Central is more oxidized than the average continental lithosphere, although the origin of this anomaly remains unknown. Using iron oxidation analysis in clinopyroxene, oxybarometry, and melt inclusions in mantle xenoliths, we show that widespread infiltration of volatile (HCSO)-rich silicic melts played a major role in this oxidation. We propose the first comprehensive model of magmatism and mantle oxidation at an intraplate setting. Two oxidizing events occurred: (1) a 365–286 Ma old magmatic episode that produced alkaline vaugnerites, potassic lamprophyres, and K-rich calc-alkaline granitoids, related to the N–S Rhenohercynian subduction, and (2) < 30 Ma old magmatism related to W–E extension, producing carbonatites and hydrous potassic trachytes. These melts were capable of locally increasing the subcontinental lithospheric mantle fO2 to FMQ + 2.4. Both events originate from the melting of a metasomatized lithosphere containing carbonate + phlogopite ± amphibole. The persistence of this volatile-rich lithospheric source implies the potential for new episodes of volatile-rich magmatism. Similarities with worldwide magmatism also show that the importance of volatiles and the oxidation of the mantle in intraplate regions is underestimated.

  12. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    Energy Technology Data Exchange (ETDEWEB)

    Denayer, Jessica [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Bister, Geoffroy [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Simonis, Priscilla [Laboratory LPS, University of Namur, rue de bruxelles 61, 5000 Namur (Belgium); Colson, Pierre; Maho, Anthony [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Aubry, Philippe [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Vertruyen, Bénédicte [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Henrist, Catherine, E-mail: catherine.henrist@ulg.ac.be [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium); Lardot, Véronique; Cambier, Francis [Environmental and Material Research Association (CRIBC-INISMa), avenue gouverneur cornez 4, 7000 Mons (Belgium); Cloots, Rudi [Group of Research in Energy and Environment for MATerials (GREENMAT), University of Liège, allée de la chimie 3, 4000 Liège (Belgium)

    2014-12-01

    Highlights: • Surfactant-assisted USP: a novel and low cost process to obtain high quality nickel oxide films, with or without lithium dopant. • Increased uniformity and reduced light scattering thanks to the addition of a surfactant. • Improved electrochromic performance (coloration efficiency and contrast) for lithium-doped films by comparison with the undoped NiO film. - Abstract: Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics.

  13. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks

    Science.gov (United States)

    Jones, J. Graham; Warner, C. G.

    1972-01-01

    Graham Jones, J., and Warner, C. G. (1972).Brit. J. industr. Med.,29, 169-177. Chronic exposure to iron oxide, chromium oxide, and nickel oxide fumes of metal dressers in a steelworks. Occupational and medical histories, smoking habits, respiratory symptoms, chest radiographs, and ventilatory capacities were studied in 14 steelworkers employed as deseamers of steel ingots for periods of up to 16 years. The men were exposed for approximately five hours of each working shift to fume concentrations ranging from 1·3 to 294·1 mg/m3 made up mainly of iron oxide with varying proportions of chromium oxide and nickel oxide. Four of the men, with 14 to 16 years' exposure, showed radiological evidence of pneumoconiosis classified as ILO categories 2 or 3. Of these, two had pulmonary function within the normal range and two had measurable loss of function, moderate in one case and mild in the other. Many observers would diagnose these cases as siderosis but the authors consider that this term should be reserved for cases exposed to pure iron compounds. The correct diagnosis is mixed-dust pneumoconiosis and the loss of pulmonary function is caused by the effects of the mixture of metallic oxides. It is probable that inhalation of pure iron oxide does not cause fibrotic pulmonary changes, whereas the inhalation of iron oxide plus certain other substances obviously does. Images PMID:5021996

  14. Synthesis of bacteria promoted reduced graphene oxide-nickel sulfide networks for advanced supercapacitors.

    Science.gov (United States)

    Zhang, Haiming; Yu, Xinzhi; Guo, Di; Qu, Baihua; Zhang, Ming; Li, Qiuhong; Wang, Taihong

    2013-08-14

    Supercapacitors with potential high power are useful and have attracted much attention recently. Graphene-based composites have been demonstrated to be promising electrode materials for supercapacitors with enhanced properties. To improve the performance of graphene-based composites further and realize their synthesis with large scale, we report a green approach to synthesize bacteria-reduced graphene oxide-nickel sulfide (BGNS) networks. By using Bacillus subtilis as spacers, we deposited reduced graphene oxide/Ni3S2 nanoparticle composites with submillimeter pores directly onto substrate by a binder-free electrostatic spray approach to form BGNS networks. Their electrochemical capacitor performance was evaluated. Compared with stacked reduced graphene oxide-nickel sulfide (GNS) prepared without the aid of bacteria, BGNS with unique nm-μm structure exhibited a higher specific capacitance of about 1424 F g(-1) at a current density of 0.75 A g(-1). About 67.5% of the capacitance was retained as the current density increased from 0.75 to 15 A g(-1). At a current density of 75 A g(-1), a specific capacitance of 406 F g(-1) could still remain. The results indicate that the reduced graphene oxide-nickel sulfide network promoted by bacteria is a promising electrode material for supercapacitors.

  15. Potassium/calcium/nickel oxide catalysts for the oxidative coupling of methane

    NARCIS (Netherlands)

    Dooley, K.; Dooley, Kerry M.; Ross, J.R.H.; Ross, Julian R.H.

    1992-01-01

    A series of potassium/calcium/nickel oxides were tested for the oxidative coupling of methane (OCM) at 843–943 K and water addition to the feed at 0–66 mol-%. The K/Ni ratios varied from 0.0–0.6 and Ca/Ni from 0.0–11; catalysts with no nickel were also tested. At least 10% water in the feed and

  16. Electrodeposition of Manganese-Nickel Oxide Films on a Graphite Sheet for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hae-Min Lee

    2014-01-01

    Full Text Available Manganese-nickel (Mn-Ni oxide films were electrodeposited on a graphite sheet in a bath consisting of manganese acetate and nickel chloride, and the structural, morphological, and electrochemical properties of these films were investigated. The electrodeposited Mn-Ni oxide films had porous structures covered with nanofibers. The X-ray diffractometer pattern revealed the presence of separate manganese oxide (g-MnO2 and nickel oxide (NiO in the films. The electrodeposited Mn-Ni oxide electrode exhibited a specific capacitance of 424 F/g in Na2SO4 electrolyte. This electrode maintained 86% of its initial specific capacitance over 2000 cycles of the charge-discharge operation, showing good cycling stability.

  17. Comparative Investigation of 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 Cathode Materials Synthesized by Using Different Lithium Sources

    Directory of Open Access Journals (Sweden)

    Peng-Bo Wang

    2018-05-01

    Full Text Available Lithium-rich manganese-based cathode materials has been attracted enormous interests as one of the most promising candidates of cathode materials for next-generation lithium ion batteries because of its high theoretic capacity and low cost. In this study, 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 materials are synthesized through a solid-state reaction by using different lithium sources, and the synthesis process and the reaction mechanism are investigated in detail. The morphology, structure, and electrochemical performances of the material synthesized by using LiOH·H2O, Li2CO3, and CH3COOLi·2H2O have been analyzed by using Thermo gravimetric analysis (TGA, X-ray diffraction (XRD, Scanning electron microscope (SEM, Transmission electron microscope (TEM, X-ray photoelectron spectroscopy (XPS, and electrochemical measurements. The 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 material prepared by using LiOH·H2O displays uniform morphology with nano particle and stable layer structure so that it suppresses the first cycle irreversible reaction and structure transfer, and it delivers the best electrochemical performance. The results indicate that LiOH·H2O is the best choice for the synthesis of the 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 material.

  18. Chemically grown, porous, nickel oxide thin-film for electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Inamdar, A.I.; Kim, YoungSam; Im, Hyunsik [Department of Semiconductor Science, Dongguk University, Seoul 100-715 (Korea, Republic of); Pawar, S.M.; Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Kim, Hyungsang [Department of Physics, Dongguk University, Seoul 100-715 (Korea, Republic of)

    2011-02-15

    A porous nickel oxide film is successfully synthesized by means of a chemical bath deposition technique from an aqueous nickel nitrate solution. The formation of a rock salt NiO structure is confirmed with XRD measurements. The electrochemical supercapacitor properties of the nickel oxide film are examined using cyclic voltammetery (CV), galvanostatic and impedance measurements in two different electrolytes, namely, NaOH and KOH. A specific capacitance of {proportional_to}129.5 F g{sup -1} in the NaOH electrolyte and {proportional_to}69.8 F g{sup -1} in the KOH electrolyte is obtained from a cyclic voltammetery study. The electrochemical stability of the NiO electrode is observed for 1500 charge-discharge cycles. The capacitative behaviour of the NiO electrode is confirmed from electrochemical impedance measurements. (author)

  19. Nanoroses of nickel oxides: Synthesis, electron tomography study, and application in CO oxidation and energy storage

    KAUST Repository

    Fihri, Aziz

    2012-04-11

    Nickel oxide and mixed-metal oxide structures were fabricated by using microwave irradiation in pure water. The nickel oxide self-assembled into unique rose-shaped nanostructures. These nickel oxide roses were studied by performing electron tomography with virtual cross-sections through the particles to understand their morphology from their interior to their surface. These materials exhibited promising performance as nanocatalysts for CO oxidation and in energy storage devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Inkjet-printed p-type nickel oxide thin-film transistor

    Science.gov (United States)

    Hu, Hailong; Zhu, Jingguang; Chen, Maosheng; Guo, Tailiang; Li, Fushan

    2018-05-01

    High-performance inkjet-printed nickel oxide thin-film transistors (TFTs) with Al2O3 high-k dielectric have been fabricated using a sol-gel precursor ink. The "coffee ring" effect during the printing process was facilely restrained by modifying the viscosity of the ink to control the outward capillary flow. The impacts on the device performance was studied in detail in consideration of annealing temperature of the nickel oxide film and the properties of dielectric layer. The optimized switching ability of the device were achieved at an annealing temperature of 280 °C on a 50-nm-thick Al2O3 dielectric layer, with a hole mobility of 0.78 cm2/V·s, threshold voltage of -0.6 V and on/off current ratio of 5.3 × 104. The as-printed p-type oxide TFTs show potential application in low-cost, large-area complementary electronic devices.

  1. Engineered nickel oxide nanoparticle causes substantial physicochemical perturbation in plants

    Science.gov (United States)

    Manna, Indrani; Bandyopadhyay, Maumita

    2017-11-01

    Concentration of engineered NiO-NP in nature is on the rise, owing to large scale industrial uses and human interventions, which have accreted the scope of exposure especially at the primary trophic levels of the ecosystem. Nickel content in air, drinking water and soil is already above permissible limits in most parts of the developed world. Though nickel oxide is an essential micronutrient in the animal system, it has already been graded as a human carcinogen by WHO, and numerous studies have established the toxic nature of nickel in higher dosage in the animal system. Though studies depicting toxicity and bioaccumulation of nickel in plants is documented, the interaction of nickel oxide nanoparticle with plants is not fully a well-studied, well elucidated topic. What is known is that, exposure to nickel oxide nanoparticle, arouses stress response and leads to cytotoxicity and growth retardation in a handful of plants, a defined work on the intricate physicochemical cellular responses and genotoxic challenges has been so far absent. We have tried to fill in such gaps with this study. We planned the work around pertinent hypotheses like: whether NiO-NP cause cytotoxicity in a model plant system (Allium cepa L.)?If so, does internalization of nickel ion (the potent toxic) take place in the tissue? Does internalized NiO-NP create furore in the antioxidant enzyme system of the plant leading to cytotoxicity? In that case, whether the ENP causes genotoxicity and leads to pycknosis of the cell. The study has been designed to assess the change in biochemical profile and genotoxicity potential of NiO-NP at a wide range of concentrations using root tips of Allium cepa L., the model system for study of cytotoxicity and genotoxicity, and four of its closest relatives, Allium sativum L., Allium schoenoprasum L., Allium porrum L., Allium fistulosum L., chosen for their immense economic importance. Growing root tips were treated with seven different concentrations of Ni

  2. Adsorption and bio-sorption of nickel ions and reuse for 2-chlorophenol catalytic ozonation oxidation degradation from water

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Wei, E-mail: chmawv@yahoo.com [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Zong, Panpan; Cheng, Zihong [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Wang, Baodong; Sun, Qi [National Institute of Clean-and-low Carbon Energy, Beijing 102209 (China)

    2014-02-15

    Highlights: • Biomass and fly ash which were widespread for adsorption of heavy metal ions. • Preparation of catalyst by saturated adsorbents for 2-chlorophenol ozone degradation. • This work demonstrated that the O{sub 3}/catalyst process was an effective pathway. • The use of nickel ions, fly ash and sawdust to achieve the recycling utilization of resources. -- Abstract: This work explored the preparation of an effective and low-cost catalyst and investigated its catalytic capacity for 2-chlorophenol ozonation oxidation degradation in wastewater by using an ozone oxidation batch reactor. The catalyst was directly prepared by the reuse of fly ash and sawdust after saturated adsorption of nickel ions from wastewater, which was proposed as an efficient and economic approach. The obtained catalyst was characterized by TGA, BET, FTIR, XRD, and SEM, the results showed that fly ash as the basic framework has high specific surface area and the addition of sawdust as the porogen agent could improve the pore structure of the catalyst. The adsorption of nickel ions by fly ash and sawdust from aqueous solution was also investigated in this study. The results obtained from the experiments indicated that adsorption of nickel ions by fly ash and biomass sawdust could be well described by Langmuir isotherm model and pseudo second order kinetic model. The catalytic performance of catalyst was studied in terms of the effect of time, liquid–solid ratio and pH on 2-chlorophenol ozonation degradation. It was found that the catalyst could effectively improve the ozonation reaction rate at pH = 7 with a 2:1 liquid–solid ratio. The kinetic study demonstrated that the reaction followed the first order model, and the rate constant increased 267% (0.03–0.1 min{sup −1}) of 2-chlorophenol ozonation degradation with 5 mmol/L concentration at pH = 7.0 compared with ozonation alone.

  3. The Effect of Annealing Temperature on Nickel on Reduced Graphene Oxide Catalysts on Urea Electrooxidation

    International Nuclear Information System (INIS)

    Glass, Dean E.; Galvan, Vicente; Prakash, G.K. Surya

    2017-01-01

    Highlights: •Nickel was reduced on graphene oxide and annealed under argon from 300 to 700 °C. •Nickel was oxidized from the removal of oxygen groups on the graphene oxide. •Higher annealed catalysts displayed decreased urea electrooxidation currents. •Micro direct urea/hydrogen peroxide fuel cells were employed for the first time. •Ni/rGO catalysts displayed enhanced fuel cell performance than the bare nickel. -- Abstract: The annealing temperature effects on nickel on reduced graphene oxide (Ni/rGO) catalysts for urea electrooxidation were investigated. Nickel chloride was directly reduced in an aqueous solution of graphene oxide (GO) followed by annealing under argon at 300, 400, 500, 600, and 700 °C, respectively. X-ray Diffraction (XRD) patterns revealed an increase in the crystallite size of the nickel nanoparticles while the Raman spectra displayed an increase in the graphitic disorder of the reduced graphene oxide at higher annealing temperatures due to the removal of oxygen functional groups. The Ni/rGO catalysts annealed at higher temperatures displayed oxidized nickel surface characteristics from the Ni 2p X-ray Photoelectron Spectra (XPS) due to the oxidation of the nickel from the oxygen functional groups in the graphitic lattice. In the half-cell testing, the onset potential of urea electrooxidation decreased while the urea electrooxidation currents decreased as the annealing temperature was increased. The nickel catalyst annealed at 700 °C displayed a 31% decrease in peak power density while the catalyst annealed at 300 °C displayed a 13% increase compared with the unannealed Ni/rGO catalyst in the micro direct urea/hydrogen peroxide fuel cells tests.

  4. Fabrication technology of CNT-Nickel Oxide based planar pseudocapacitor for MEMS and NEMS

    Science.gov (United States)

    Lebedev, E. A.; Kitsyuk, E. P.; Gavrilin, I. M.; Gromov, D. G.; Gruzdev, N. E.; Gavrilov, S. A.; Dronov, A. A.; Pavlov, A. A.

    2015-11-01

    Fabrication technology of planar pseudocapacitor (PsC) based on carbon nanotube (CNT) forest, synthesized using plasma enhanced chemical vapor deposition (PECVD) method, covered with thin nickel oxide layer deposited by successive ionic layer adsorption and reaction (SILAR) method, is demonstrated. Dependences of deposited oxide layers thickness on device specific capacities is studied. It is shown that pseudocapacity of nickel oxide thin layer increases specific capacity of the CNT's based device up to 2.5 times.

  5. 3-D periodic mesoporous nickel oxide for nonenzymatic uric acid sensors with improved sensitivity

    International Nuclear Information System (INIS)

    Huang, Wei; Cao, Yang; Chen, Yong; Zhou, Yang; Huang, Qingyou

    2015-01-01

    Graphical abstract: The enzyme-less amperometric sensor based on 3-D periodic mesoporous NiO nanomaterials used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM"−"1 cm"−"2. - Highlights: • Microwave-assisted method was used to fabricate the 3-D periodic mesoporous NiO particles. • The mesoporous nickel oxide was applied to nonenzymatic uric acid biosensor. • The detection limit is 0.005 μM over wide linear detection ranges up to 0.374 mM. • The sensitivity is 756.26 μA mM"−"1 cm"−"2. - Abstract: 3-D periodic mesoporous nickel oxide (NiO) particles with crystalline walls have been synthesized through the microwave-assisted hard template route toward the KIT-6 silica. It was investigated as a nonenzymatic amperometric sensor for the detection of uric acid. 3-D periodic nickel oxide matrix has been obtained by the hard template route from the KIT-6 silica template. The crystalline nickel oxide belonged to the Ia3d space group, and its structure was characterized by X-ray diffraction (XRD), N_2 adsorption–desorption, and transmission electron microscopy (TEM). The analysis results showed that the microwave-assisted mesoporous NiO materials were more appropriate to be electrochemical sensors than the traditional mesoporous NiO. Cyclic voltammetry (CV) revealed that 3-D periodic NiO exhibited a direct electrocatalytic activity for the oxidation of uric acid in sodium hydroxide solution. The enzyme-less amperometric sensor used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM"−"1 cm"−"2, and a possible mechanism was also given in the paper.

  6. 3-D periodic mesoporous nickel oxide for nonenzymatic uric acid sensors with improved sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wei; Cao, Yang, E-mail: caowang507@163.com; Chen, Yong; Zhou, Yang; Huang, Qingyou

    2015-12-30

    Graphical abstract: The enzyme-less amperometric sensor based on 3-D periodic mesoporous NiO nanomaterials used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM{sup −1} cm{sup −2}. - Highlights: • Microwave-assisted method was used to fabricate the 3-D periodic mesoporous NiO particles. • The mesoporous nickel oxide was applied to nonenzymatic uric acid biosensor. • The detection limit is 0.005 μM over wide linear detection ranges up to 0.374 mM. • The sensitivity is 756.26 μA mM{sup −1} cm{sup −2}. - Abstract: 3-D periodic mesoporous nickel oxide (NiO) particles with crystalline walls have been synthesized through the microwave-assisted hard template route toward the KIT-6 silica. It was investigated as a nonenzymatic amperometric sensor for the detection of uric acid. 3-D periodic nickel oxide matrix has been obtained by the hard template route from the KIT-6 silica template. The crystalline nickel oxide belonged to the Ia3d space group, and its structure was characterized by X-ray diffraction (XRD), N{sub 2} adsorption–desorption, and transmission electron microscopy (TEM). The analysis results showed that the microwave-assisted mesoporous NiO materials were more appropriate to be electrochemical sensors than the traditional mesoporous NiO. Cyclic voltammetry (CV) revealed that 3-D periodic NiO exhibited a direct electrocatalytic activity for the oxidation of uric acid in sodium hydroxide solution. The enzyme-less amperometric sensor used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM{sup −1} cm{sup −2}, and a possible mechanism was also given in the paper.

  7. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films

    KAUST Repository

    Sun, Ke; Saadi, Fadl H.; Lichterman, Michael F.; Hale, William G.; Wang, Hsinping; Zhou, Xinghao; Plymale, Noah T.; Omelchenko, Stefan T.; He, Jr-Hau; Papadantonakis, Kimberly M.; Brunschwig, Bruce S.; Lewis, Nathan S.

    2015-01-01

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide

  8. Suppressed oxygen extraction and degradation of LiNixMnyCozO2 cathodes at high charge cut-off voltages

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianming; Yan, Pengfei; Zhang, Jiandong; Engelhard, Mark H.; Zhu, Zihua; Polzin, Bryant J.; Trask, Steve; Xiao, Jie; Wang, Chongmin; Zhang, Jiguang

    2017-09-01

    The capacity degradation mechanism in lithium nickel-manganese-cobalt oxide (NMC) cathodes (LiNi1/3Mn1/3Co1/3O2 (NMC333) and LiNi0.4Mn0.4Co0.2O2 (NMC442)) during high-voltage (cut-off of 4.8 V) operation has been investigated. In contrast to NMC442, NMC333 exhibits rapid structural changes including severe micro-crack formation and phase transformation from a layered to a disordered rock-salt structure, as well as interfacial degradation during high-voltage cycling, leading to a rapid increase of the electrode resistance and fast capacity decline. The fundamental reason behind the poor structural and interfacial stability of NMC333 was found to be correlated to its high Co content and the significant overlap between the Co3+/4+ t(2g) and O2- 2p bands, resulting in oxygen removal and consequent structural changes at high voltages. In addition, oxidation of the electrolyte solvents by the extracted oxygen species generates acidic species, which then attack the electrode surface and form highly resistive LiF. These findings highlight that both the structural and interfacial stability should be taken into account when tailoring cathode materials for high voltage battery systems

  9. Catalytic Water Oxidation by a Bio-inspired Nickel Complex with a Redox-Active Ligand.

    Science.gov (United States)

    Wang, Dong; Bruner, Charlie O

    2017-11-20

    The oxidation of water (H 2 O) to dioxygen (O 2 ) is important in natural photosynthesis. One of nature's strategies for managing such multi-electron transfer reactions is to employ redox-active metal-organic cofactor arrays. One prototype example is the copper tyrosinate active site found in galactose oxidase. In this work, we have implemented such a strategy to develop a bio-inspired nickel phenolate complex capable of catalyzing the oxidation of H 2 O to O 2 electrochemically at neutral pH with a modest overpotential. Employment of the redox-active ligand turned out to be a useful strategy to avoid the formation of high-valent nickel intermediates while a reasonable turnover rate (0.15 s -1 ) is retained.

  10. SAFT 4{1/2} inch nickel hydrogen battery cells

    Energy Technology Data Exchange (ETDEWEB)

    Duquesne, D.; Lacout, B.; Sennet, A. [SAFT Advanced Batteries, Poitiers (France)

    1995-12-31

    SAFT Advanced Batteries has now produced over 400 high capacity 4{1/2} inch Nickel Hydrogen Battery Cells for flight programs. The 4.5 inch diameter, rabbit-ear cell design is designed to provide the anticipated energy required at the lowest practical weight. SAFT has incorporated into the design of the dry-powder nickel electrode, truly hermetic ceramic to metal seals, qualified terminal feedthroughs, high reliability mechanical design, composite pure platinum negative electrode, and zircar separator, plus more than 25 years experience in aerospace nickel cell technology, resulting in a 4{1/2} inch configuration with the 3{1/2} inch cell design carryover heritage. General performance requirements for GEO missions that SAFT cells meet are 15 years in orbit lifetime, 80% DOD, low mass to energy ratios, and flexible capacity by modifying number of electrodes in the stack. This design is qualified for geostationary orbits based on SAFT`s 3{1/2} inch qualification heritage, design verification, and cycling performed by customer Space Systems/LORAL in support of the INTELSAT VIIA and N-STAR flight programs.

  11. Electron transfer behaviour of single-walled carbon nanotubes electro-decorated with nickel and nickel oxide layers

    Energy Technology Data Exchange (ETDEWEB)

    Adekunle, Abolanle S.; Ozoemena, Kenneth I. [Department of Chemistry, University of Pretoria, Pretoria 0002 (South Africa)

    2008-08-01

    The electron transfer behaviour of nickel film-decorated single-walled carbon nanotubes (SWCNTs-Ni) at edge plane pyrolytic graphite electrodes (EPPGEs) was investigated. The impact of SWCNTs on the redox properties of the nickel film was investigated with cyclic voltammetry and electrochemical impedance spectroscopy (EIS). From EIS data, obtained using ferrocyanide/ferricyanide as a redox probe, we show that the electrodes based on nickel and nickel oxide films follow electrical equivalent circuit models typical of partial charge transfer or adsorption-controlled kinetics, resembling the 'electrolyte-insulator-semiconductor sensors (EIS)'. From the models, we prove that EPPGE-SWCNT-Ni exhibits the least resistance to charge transport compared to other electrodes (approximately 30 times faster than the EPPGE-SWCNT-NiO, 25 times faster than EPPGE-SWCNT, and over 300 times faster than the bare EPPGE) suggesting the ability of the SWCNTs to act as efficient conducting species that facilitate electron transport of the integrated nickel and nickel oxide particles. (author)

  12. Spin glass transition in the rhombohedral LiNi1/3Mn1/3Co1/3O2

    International Nuclear Information System (INIS)

    Bie, Xiaofei; Yang, Xu; Han, Bing; Chen, Nan; Liu, Lina; Wei, Yingjin; Wang, Chunzhong; Chen, Hong; Du, Fei; Chen, Gang

    2013-01-01

    Highlights: •The Rietveld analysis of XRD data reveals a single phase with rhombohedral structure. •Dc susceptibility data suggest a spin glass behavior at low T in the 333 compound. •The ac susceptibility measurements have been observed in the typical SG system. •Three models have been employed to study the behavior of the spin glass state. •Both geometrical frustration and disorder play important role in the formation of SG. -- Abstract: Layered LiNi 1/3 Mn 1/3 Co 1/3 O 2 has been synthesized by co-precipitation method, and the magnetic properties were comprehensively studied by dc and ac susceptibilities. The dc magnetization curves show the irreversibility and spin freezing behavior at 109 K and 9 K. The evolution of real and imaginary part of ac susceptibility under different frequencies indicates a spin glass transition at low temperature. Three models (the Néel–Arrhenius law, the Vogel–Fulcher law, and the power law) have been employed to study the relaxation behavior of the spin glass state. Both frustration and disorder play important role in the formation of spin glass

  13. Reduction of nickel oxide particles by hydrogen studied in an environmental TEM

    DEFF Research Database (Denmark)

    Jeangros, Q.; Hansen, Thomas Willum; Wagner, Jakob Birkedal

    2013-01-01

    In situ reduction of nickel oxide (NiO) particles is performed under 1.3 mbar of hydrogen gas (H2) in an environmental transmission electron microscope (ETEM). Images, diffraction patterns and electron energy-loss spectra (EELS) are acquired to monitor the structural and chemical evolution of the...

  14. Kinetic studies of isooctane partial oxidation over a nickel-based catalyst

    International Nuclear Information System (INIS)

    Ibrahim, Hussameldin; Idem, Raphael; Aboudheir, Ahmed

    2006-01-01

    The production of hydrogen (H 2 ) for fuel cell applications in mobile vehicles by reforming technologies such as partial oxidation of various fossil fuels has gained much attention recently. In this study, the production of H 2 by the catalytic partial oxidation of isooctane ((C 8 H 18 ) used here as a surrogate for gasoline) was investigated over alumina (AI 2 O 3 )supported nickel (Ni) catalyst. The work investigated the kinetics of the partial oxidation of isooctane over a stable Ni/□-AI 2 O 3 catalyst in the range of 863 to 913 K, at atmospheric pressure, W/F i c8 in the range of 1.97 to 8.58 g h mol - 1, and molar feed ratio in the range of 2.0 to 8.0 experiments to obtain kinetic data were performed in a 12.7 mm diameter Inconel micro-reactor housed in an electrically controlled furnace. The chemical reaction was then modeled using rate models developed from the Langmuir-Hinshelwood-hougen-Watson (LHHW) and Eley-Rideal (ER) formulations. The model parameters were estimated using an adaptive Gauss-Newton and Marquardi-Levenberg minimization algorithm. Rival models were screened for their thermodynamic consistency and physicochemical significance of estimated parameters. Langmuir-Hinshelwood-hougen-Watson mechanism requiring the dissociative adsorption of isooctane and oxygen on two different sites appeared to be the most likely pathway for the partial oxidation reaction of isooctane. Reaction order with respect to isooctane indicates the strong coverage of nickel by isooctane. The activation energy of 73±3.1 kJ mol - 1 estimated from the LHHW model is consistent with the trend observed with lower hydrocarbons.(Author)

  15. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films.

    Science.gov (United States)

    Sun, Ke; Saadi, Fadl H; Lichterman, Michael F; Hale, William G; Wang, Hsin-Ping; Zhou, Xinghao; Plymale, Noah T; Omelchenko, Stefan T; He, Jr-Hau; Papadantonakis, Kimberly M; Brunschwig, Bruce S; Lewis, Nathan S

    2015-03-24

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silicon, crystalline n-type cadmium telluride, and hydrogenated amorphous silicon. Under anodic operation in 1.0 M aqueous potassium hydroxide (pH 14) in the presence of simulated sunlight, the NiOx films stabilized all of these self-passivating, high-efficiency semiconducting photoelectrodes for >100 h of sustained, quantitative solar-driven oxidation of water to O2(g).

  16. Catalytic Water Oxidation by a Bio-inspired Nickel Complex with Redox Active Ligand

    Science.gov (United States)

    Wang, Dong; Bruner, Charlie O.

    2017-01-01

    The oxidation of water to dioxygen is important in natural photosynthesis. One of nature’s strategies for managing such multi-electron transfer reactions is to employ redox active metal-organic cofactor arrays. One prototype example is the copper-tyrosinate active site found in galactose oxidase. In this work, we have implemented such a strategy to develop a bio-inspired nickel-phenolate complex capable of catalyzing the oxidation of water to O2 electrochemically at neutral pH with a modest overpotential. The employment of the redox-active ligand turned out to be a useful strategy to avoid the formation of high-valent nickel intermediates while a reasonable turnover rate (0.15 s−1) is retained. PMID:29099176

  17. Study of the oxidation kinetics of the nickel-molybdenum alloy

    International Nuclear Information System (INIS)

    Gouillon, Marie-Josephe

    1974-01-01

    This research thesis reports the study of the oxidation of a nickel-molybdenum alloy in the high-nickel-content part of this alloy. After a bibliographical study on the both metals, the author proposes a physical model based on observed phenomena and based on experimental results. Based on a thermodynamic study, the author compares the stability of the different oxides which may be formed, and reports a prediction of oxides obtained on the alloy during oxidation. Qualitative and quantitative studies have been performed by scanning electron microscopy coupled with electronic microprobe analysis to investigate morphological characteristics on oxidation films. A kinetic study by thermogravimetry shows a decrease of the alloy oxidation rate with respect to that of pure nickel at temperatures lower than 800 degrees C. This result is interpreted by the intervention of two opposed diffusion phenomena which act against each other [fr

  18. Stress corrosion crack tip microstructure in nickel-based alloys

    International Nuclear Information System (INIS)

    Shei, S.A.; Yang, W.J.

    1994-04-01

    Stress corrosion cracking behavior of several nickel-base alloys in high temperature caustic environments has been evaluated. The crack tip and fracture surfaces were examined using Auger/ESCA and Analytical Electron Microscopy (AEM) to determine the near crack tip microstructure and microchemistry. Results showed formation of chromium-rich oxides at or near the crack tip and nickel-rich de-alloying layers away from the crack tip. The stress corrosion resistance of different nickel-base alloys in caustic may be explained by the preferential oxidation and dissolution of different alloying elements at the crack tip. Alloy 600 (UNS N06600) shows good general corrosion and intergranular attack resistance in caustic because of its high nickel content. Thermally treated Alloy 690 (UNS N06690) and Alloy 600 provide good stress corrosion cracking resistance because of high chromium contents along grain boundaries. Alloy 625 (UNS N06625) does not show as good stress corrosion cracking resistance as Alloy 690 or Alloy 600 because of its high molybdenum content

  19. Bulletin of Materials Science | News

    Indian Academy of Sciences (India)

    ... nickel oxides, LiNi0.8M0.2O2 and LiCo0.8M0.2O2 (M = Mg2+, Ca2+, Ba2+), ... Department of Industrial Chemistry, Alagappa University, Karaikudi 630 003, India; Department of Chemical Engineering, Yonsei University, Seodaemun-Ku, ...

  20. Photoelectrochemical characterization of squaraine-sensitized nickel oxide cathodes deposited via screen-printing for p-type dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Naponiello, Gaia; Venditti, Iole [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Zardetto, Valerio [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Saccone, Davide [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Di Carlo, Aldo [Centre for Hybrid and Organic Solar Energy, Department of Electronic Engineering, University of Rome - Tor Vergata, via del Politecnico 1, 00133 Rome (Italy); Fratoddi, Ilaria [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Center for Nanotechnology for Engineering (CNIS), Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy); Barolo, Claudia [Department of Chemistry and NIS, Interdepartmental Centre of Excellence, University of Torino, via Pietro Giuria 7, I-10125 Torino (Italy); Dini, Danilo, E-mail: danilo.dini@uniroma1.it [Department of Chemistry, Sapienza University of Rome P.le A. Moro 5, 00185 Rome (Italy)

    2015-11-30

    Graphical abstract: Screen-printing method has been adopted for the deposition of nickel oxide thin film electrodes with mesoporous features. Nickel oxide was sensitized with three newly synthesized squaraines (VG1C8,VG10C8 and DS2/35) and employed as photoelectroactive cathode of p-type dye-sensitized solar cells. Colorant erythrosine b (EB) was taken as commercial benchmark for comparative purposes. Sensitization was successful with the attainment of overall conversion efficiencies in the order of 0.025% when the mesoporous surface of nickel oxide was alkali treated. The prolongation of nickel oxide sensitization time up to 16 h led to a general increase of the open circuit voltage in the corresponding solar cells. - Highlights: • We deposited nickel oxide with screen-printing technique utilizing nickel oxide nanoparticles. • We employed screen-printed nickel oxide as cathodes of p-DSCs. • We employed new squaraine as sensitizers of screen-printed nickel oxide. • Further progress is expected when the formulation of the screen-printing paste will be optimized. - Abstract: In the present paper we report on the employment of the screen-printing method for the deposition of nickel oxide (NiO{sub x}) layers when preformed nanoparticles of the metal oxide (diameter < 50 nm) constitute the precursors in the paste. The applicative purpose of this study is the deposition of mesoporous NiO{sub x} electrodes in the configuration of thin films (thickness, l ≤ 4 μm) for the realization of p-type dye-sensitized solar cells (p-DSCs). Three different squaraine-based dyes (here indicated with VG1C8, VG10C8 and DS2/35), have been used for the first time as sensitizers of a p-type DSC electrode. VG1C8 and VG10C8 present two carboxylic groups as anchoring moieties, whereas DS2/35 sensitizer possesses four acidic anchoring groups. All three squaraines are symmetrical and differ mainly for the extent of electronic conjugation. The colorant erythrosine b (ERY B) was taken as

  1. 3-D periodic mesoporous nickel oxide for nonenzymatic uric acid sensors with improved sensitivity

    Science.gov (United States)

    Huang, Wei; Cao, Yang; Chen, Yong; Zhou, Yang; Huang, Qingyou

    2015-12-01

    3-D periodic mesoporous nickel oxide (NiO) particles with crystalline walls have been synthesized through the microwave-assisted hard template route toward the KIT-6 silica. It was investigated as a nonenzymatic amperometric sensor for the detection of uric acid. 3-D periodic nickel oxide matrix has been obtained by the hard template route from the KIT-6 silica template. The crystalline nickel oxide belonged to the Ia3d space group, and its structure was characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and transmission electron microscopy (TEM). The analysis results showed that the microwave-assisted mesoporous NiO materials were more appropriate to be electrochemical sensors than the traditional mesoporous NiO. Cyclic voltammetry (CV) revealed that 3-D periodic NiO exhibited a direct electrocatalytic activity for the oxidation of uric acid in sodium hydroxide solution. The enzyme-less amperometric sensor used in the detection of uric acid with detection limit of 0.005 μM (S/N = 3) over wide linear detection ranges up to 0.374 mM and with a high sensitivity of 756.26 μA mM-1 cm-2, and a possible mechanism was also given in the paper.

  2. High Tap Density Spherical Li[Ni0.5Mn0.3Co0.2]O2 Cathode Material Synthesized via Continuous Hydroxide Coprecipitation Method for Advanced Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Shunyi Yang

    2012-01-01

    Full Text Available Spherical [Ni0.5Mn0.3Co0.2](OH2 precursor with narrow size distribution and high tap density has been successfully synthesized by a continuous hydroxide coprecipitation, and Li[Ni0.5Mn0.3Co0.2]O2 is then prepared by mixing the precursor with 6% excess Li2CO3 followed by calcinations. The tap density of the obtained Li[Ni0.5Mn0.3Co0.2]O2 powder is as high as 2.61 g cm−3. The powders are characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, scanning electron microscope (SEM, particle size distribution (PSD, and charge/discharge cycling. The XRD studies show that the prepared Li[Ni0.5Mn0.3Co0.2]O2 has a well-ordered layered structure without any impurity phases. Good packing properties of spherical secondary particles (about 12 μm consisted of a large number of tiny-thin plate-shape primary particles (less than 1 μm, which can be identified from the SEM observations. In the voltage range of 3.0–4.3 V and 2.5–4.6 V, Li[Ni0.5Mn0.3Co0.2]O2 delivers the initial discharge capacity of approximately 175 and 214 mAh g−1 at a current density of 32 mA g−1, and the capacity retention after 50 cycles reaches 98.8% and 90.2%, respectively. Besides, it displays good high-temperature characteristics and excellent rate capability.

  3. Systematic study of nickel oxide ceramic pigment using Ni C O3.2 Ni(O H)2.4 H2 O as precursor

    International Nuclear Information System (INIS)

    Azevedo, Emilio; Longo, Elson

    1997-01-01

    The ability of some ceramics silicate and oxides have to accommodate impurity in the crystal lattice to a large colors diversity. These impurities can be both interstitial or substitutional creating crystal fields in accordance with ion-impurity valence. The technical procedures used to characterize the pigments were: DRX, IV, MEV, and BET. To optimize this property systematic studies were done for nickel oxide with a composition of 0,3% to 30%. In this work it was studied nickel oxide synthesis based on feldspar using Pechini chemistry synthesis. To obtain this powder. (author)

  4. Solvothermal coating LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 microspheres with nanoscale Li_2TiO_3 shell for long lifespan Li-ion battery cathode materials

    International Nuclear Information System (INIS)

    Wu, Naiteng; Wu, Hao; Liu, Heng; Zhang, Yun

    2016-01-01

    LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 (NCA) microspheres covered by a nanoscale Li_2TiO_3-based shell were synthesized by a facile strategy based on a solvothermal pre-coating treatment combined with a post-sintering lithiation process. The morphology, structure and composition of the Li_2TiO_3-coated NCA samples were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning scanning electron microscope (SEM) with an energy-dispersive X-ray spectroscope (EDS), and transmission electron microscopy (TEM). Owing to the complete, uniform and nanoscale Li_2TiO_3 coating shell, the resultant surface-modified NCA microspheres used as Li-ion battery cathode materials manifest remarkably enhanced cycling performances, attaining 94% and 84% capacity retention after 200 and 400 cycles at 0.5 C, respectively, which is much better than the pristine NCA counterpart (60% retention, 200 cycles). More impressively, the surface-modified NCA also shows an intriguing storage stability. After being stored at 30 °C for 50 days, the coated NCA-based cells are subjected to be cycled both at room and elevated temperatures, in which the aged cells can still remain 84% capacity retention after 200 cycles at 25 °C and 77% capacity retention after 200 cycles at 55 °C, respectively. All these results demonstrate that the Li_2TiO_3-coated LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 microsphere is a promising cathode material for Li-ion batteries with long lifespan. - Graphical abstract: Nanoscale Li_2TiO_3-based shell encapsulated LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 (NCA) microspheres are fabricated through a solvothermal pre-coating treatment combined with post-lithiation process. The surface-coated NCA as cathode materials shows a remarkably enhanced cycling performance and storage stability for long lifespan Li-ion batteries. - Highlights: • Li_2TiO_3 is used as coating materials for layer structured LiNi_0_._8Co_0_._1_5Al_0_._0_5O_2 cathode. • Solvothermal coating

  5. Structural characterization of nickel oxide/hydroxide nanosheets produced by CBD technique

    Energy Technology Data Exchange (ETDEWEB)

    Taşköprü, T., E-mail: ttaskopru@anadolu.edu.tr [Department of Physics, Anadolu University, Eskişehir 26470 (Turkey); Department of Physics, Çankırı Karatekin University, Çankırı 18100 (Turkey); Zor, M.; Turan, E. [Department of Physics, Anadolu University, Eskişehir 26470 (Turkey)

    2015-10-15

    Graphical abstract: SEM images of (a) as deposited β-Ni(OH)2 and (b) NiO samples deposited with pH 10 solution. The inset figures shows the absorbance spectra of (a) β-Ni(OH)2 and (b) NiO samples. - Highlights: • The formation of β-Ni(OH){sub 2} and NiO were confirmed with XRD, SEM, FT-IR and Raman. • Porous nickel oxide was synthesized after heat treatment of nickel hydroxide. • The increase in pH value changes the nanoflake structure to hexagonal nanosheet. • On increasing the pH from 8 to 11, the band gap decreases from 3.52 to 3.37 eV. - Abstract: Nickel hydroxide samples were deposited onto glass substrates using Ni(NO{sub 3}){sub 2}·6H{sub 2}O and aqueous ammonia by chemical bath deposition technique. The influence of pH of solution was investigated by means of X-ray diffraction, field emission scanning electron microscopy, Fourier transform infrared, Raman spectroscopy, optical absorption and BET analysis. The as-deposited samples were identified as β-Ni(OH){sub 2}, were transformed into NiO after heat treatment in air at 500 °C for 2 h. Porous nickel oxide nanosheets are obtained by heating nickel hydroxide nanosheets. The optical transitions observed in the absorbance spectra below optical band gap is due to defects or Ni{sup 2+} vacancies in NiO samples. The band gap energy of NiO samples changes between 3.37 and 3.52 eV depending on the pH values.

  6. Electrocatalytic oxidation of some anti-inflammatory drugs on a nickel hydroxide-modified nickel electrode

    Energy Technology Data Exchange (ETDEWEB)

    Hajjizadeh, M. [Department of Chemistry, Faculty of Science, K. N. Toosi University of Technology, P.O. Box 16315-1618, Tehran (Iran, Islamic Republic of); Jabbari, A. [Department of Chemistry, Faculty of Science, K. N. Toosi University of Technology, P.O. Box 16315-1618, Tehran (Iran, Islamic Republic of)], E-mail: jabbari@kntu.ac.ir; Heli, H.; Moosavi-Movahedi, A.A. [Institute of Biochemistry and Biophysics, University of Tehran, Tehran (Iran, Islamic Republic of); Haghgoo, S. [Center of Quality Control of Drug, Tehran (Iran, Islamic Republic of)

    2007-12-31

    The electrocatalytic oxidation of several anti-inflammatory drugs (mefenamic acid, diclofenac and indomethacin) was investigated on a nickel hydroxide-modified nickel (NHMN) electrode in alkaline solution. This oxidation process and its kinetics were studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy techniques. Voltammetric studies indicated that in the presence of drugs, the anodic peak current of low-valence nickel species increases, followed by a decrease in the corresponding cathodic current. This pattern indicates that drugs were oxidized on the redox mediator immobilized on the electrode surface via an electrocatalytic mechanism. A mechanism based on the electrochemical generation of Ni(III) active sites and their subsequent consumption by drugs was also investigated. The corresponding rate law under the control of charge transfer was developed and kinetic parameters were derived. In this context, the charge-transfer resistance accessible both theoretically and through impedancemetry was used as a criterion. The rate constants of the catalytic oxidation of drugs and the electron-transfer coefficients are reported. A sensitive, simple and time-saving amperometric procedure was developed for the analysis of these drugs in bulk form and for the direct assay of tablets, using the NHMN electrode.

  7. Electrocatalytic oxidation of some anti-inflammatory drugs on a nickel hydroxide-modified nickel electrode

    International Nuclear Information System (INIS)

    Hajjizadeh, M.; Jabbari, A.; Heli, H.; Moosavi-Movahedi, A.A.; Haghgoo, S.

    2007-01-01

    The electrocatalytic oxidation of several anti-inflammatory drugs (mefenamic acid, diclofenac and indomethacin) was investigated on a nickel hydroxide-modified nickel (NHMN) electrode in alkaline solution. This oxidation process and its kinetics were studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy techniques. Voltammetric studies indicated that in the presence of drugs, the anodic peak current of low-valence nickel species increases, followed by a decrease in the corresponding cathodic current. This pattern indicates that drugs were oxidized on the redox mediator immobilized on the electrode surface via an electrocatalytic mechanism. A mechanism based on the electrochemical generation of Ni(III) active sites and their subsequent consumption by drugs was also investigated. The corresponding rate law under the control of charge transfer was developed and kinetic parameters were derived. In this context, the charge-transfer resistance accessible both theoretically and through impedancemetry was used as a criterion. The rate constants of the catalytic oxidation of drugs and the electron-transfer coefficients are reported. A sensitive, simple and time-saving amperometric procedure was developed for the analysis of these drugs in bulk form and for the direct assay of tablets, using the NHMN electrode

  8. Mesoporous NiCo2O4 nanoneedles grown on 3D graphene-nickel foam for supercapacitor and methanol electro-oxidation

    International Nuclear Information System (INIS)

    Yu, Mei; Chen, Jianpeng; Liu, Jianhua; Li, Songmei; Ma, Yuxiao; Zhang, Jingdan; An, Junwei

    2015-01-01

    Mesoporous NiCo 2 O 4 nanoneedles were directly grown on three dimensional (3D) graphene-nickel foam which was prepared by chemical vapor deposition, labeled as NCO/GNF. The structure and morphology of NCO/GNF were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, element mapping and Raman spectroscopy. The NCO/GNF was employed as electrodes for supercapacitor and methanol electro-oxidation. When used for supercapacitor, the NiCo 2 O 4 nanoneedles exhibit hi exhibit high specific capacitance (1588 F g −1 at 1 A g −1 ), high power density and energy density (33.88 Wh kg −1 at 5 kW kg −1 ) as well as long cycling stability. In methanol electro-oxidation, the NiCo 2 O 4 nanoneedles deliver high electro-oxidation activity (93.3 A g −1 at 0.65 V) and electro-oxidation stability. The good electrochemical performance of NiCo 2 O 4 nanoneedles is attributed to the 3D structure with large specific area, high conductivity and fast ions/electrons transport

  9. Roentgenoelectronic investigation into oxidation of iron-chromium and iron-chromium-nickel alloys

    International Nuclear Information System (INIS)

    Akimov, A.G.; Rozenfel'd, I.L.; Kazanskij, L.P.; Machavariani, G.V.

    1978-01-01

    Kinetics of iron-chromium and iron-chromium-nickel alloy oxidation (of the Kh13 and Kh18N10T steels) in oxygen was investigated using X-ray electron spectroscopy. It was found that according to X-ray electron spectra chromium oxidation kinetics in the iron-chromium alloy differs significantly from oxidation kinetics of chromium pattern. Layer by layer X-ray electron analysis showed that chromium is subjected to a deeper oxidation as compared to iron, and accordingly, Cr 2 O 3 layer with pure iron impregnations is placed between the layer of mixed oxide (Fe 3 O 4 +Cr 2 O 3 ) and metal. A model of the iron-chromium alloy surface is suggested. The mixed oxide composition on the steel surface is presented as spinel Fesub(2+x)Crsub(1-x)Osub(y)

  10. Clad modified optical fiber gas sensors based on nanocrystalline nickel oxide embedded coatings

    Science.gov (United States)

    Yamini, K.; Renganathan, B.; Ganesan, A. R.; Prakash, T.

    2017-07-01

    A clad modified optical fiber gas sensor for sensing volatile organic compound vapours (VOCs) such as formaldehyde (HCHO), ammonia (NH3), ethanol (C2H5OH) and methanol (CH3OH) up to 500 ppm was studied using nanocrystalline nickel oxide embedded coatings. Prior to the measurements, nickel oxide in two different crystallite sizes such as 24 nm and 76 nm was synthesized by calcination of reverse precipitated nickel hydroxide subsequently at 450 °C and 900 °C for 30 min. Then, samples physical properties were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). Our gas sensing measurement concludes that the lower crystallite size (24 nm) nickel oxide nanocrystals exhibits superior performance to formaldehyde and ethanol vapours as compared with other two VOCs, the observed experimental results were discussed in detail.

  11. A highly efficient microfluidic nano biochip based on nanostructured nickel oxide.

    Science.gov (United States)

    Ali, Md Azahar; Solanki, Pratima R; Patel, Manoj K; Dhayani, Hemant; Agrawal, Ved Varun; John, Renu; Malhotra, Bansi D

    2013-04-07

    We present results of the studies relating to fabrication of a microfluidic biosensor chip based on nickel oxide nanorods (NRs-NiO) that is capable of directly measuring the concentration of total cholesterol in human blood through electrochemical detection. Using this chip we demonstrate, with high reliability and in a time efficient manner, the detection of cholesterol present in buffer solutions at clinically relevant concentrations. The microfluidic channel has been fabricated onto a nickel oxide nanorod-based electrode co-immobilized with cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) that serves as the working electrode. Bare indium tin oxide served as the counter electrode. A Ag/AgCl wire introduced to the outlet of the microchannel acts as a reference electrode. The fabricated NiO nanorod-based electrode has been characterized using X-ray diffraction, Raman spectroscopy, HR-TEM, FT-IR, UV-visible spectroscopy and electrochemical techniques. The presented NRs-NiO based microfluidic sensor exhibits linearity in the range of 1.5-10.3 mM, a high sensitivity of 0.12 mA mM(-1) cm(-2) and a low value of 0.16 mM of the Michaelis-Menten constant (Km).

  12. Improving low-temperature performance of spinel LiNi0.5Mn1.5O4 electrode and LiNi0.5Mn1.5O4/Li4Ti5O12 full-cell by coating solid-state electrolyte Li-Al-Ti-P-O

    Science.gov (United States)

    Bi, Kun; Zhao, Shi-Xi; Huang, Chao; Nan, Ce-Wen

    2018-06-01

    Octahedral cathode materials LiNi0.5Mn1.5O4 (LNMO), with primary particles size of 300-600 nm are prepared through one-step co-precipitation. Then solid-state electrolyte Li2O-Al2O3-TiO2-P2O5 (LATP) was coated on LNMO to form continuous surface-modification layer. There is no obviously difference of structure, morphology between coated LATP LiNi0.5Mn1.5O4 (LATP-LNMO) and pristine LiNi0.5Mn1.5O4 (P-LNMO). Low-temperature electrochemical performance of P-LNMO and LATP-LNMO electrodes, including charge-discharge capacity, cycle performance, middle discharge voltage and electrochemical impedance spectra (EIS), were measured systematically with three electrode. The results reveal that LATP-LNMO electrode presents superior electrochemical performance at low temperature, compared to P-LNMO electrode. At -20 °C, the capacity retention of LATP-LNMO (61%) is much higher than that of P-LNMO (39%). According to EIS, the enhancement of performance of LATP-LNMO cathode at low temperature can be attribute to LATP coating, which not only promotes lithium-ion diffusion at electrode/electrolyte interface but also decreases the charge transfer resistance. Finally, the electrochemical performances of full cell of LATP-LNMO or P-LNMO cathode vs Li4Ti5O12 anode are investigated. The energy density can be achieved to 270 Wh·Kg-1 at -20 °C if using LATP-LNMO, which is much better than that of P-LNMO.

  13. Oxidation of methanol on perovskite-type La{sub 2-x}Sr{sub x}NiO{sub 4} (0 {<=} x {<=} 1) film electrodes modified by dispersed nickel in 1 M KOH

    Energy Technology Data Exchange (ETDEWEB)

    Singh, R.N.; Singh, A.; Mishra, D.; Anindita [Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221 005 (India); Chartier, P. [Laboratoire d' Electrochimie et Chimie Physique du Corps Solide, Institut de Chimie LC3-UMR7177 CNRS/ULP, Universite Louis Pasteur, 67000, Strasbourg (France)

    2008-12-01

    Finely-dispersed nickel particles are electrodeposited on high surface-area perovskite-type La{sub 2-x}Sr{sub x}NiO{sub 4} (0 {<=} x {<=} 1) electrodes for possible use in a direct methanol fuel cell (DMFC). The study is conducted by cyclic voltammetry, chronoamperometry, impedance spectroscopy and anodic Tafel polarization techniques. The results show that the apparent electrocatalytic activities of the modified oxide electrodes are much higher than those of unmodified electrodes under similar experimental conditions; the observed activity is the greatest with the modified La{sub 1.5}Sr{sub 0.5}NiO{sub 4} electrode. At 0.550 V (vs. Hg vertical stroke HgO) in 1 M KOH + 1 M CH{sub 3}OH at 25 C, the latter electrode delivers a current density of over 200 mA cm{sup -2}, whereas other electrodes of the series produce relatively low values (65-117 mA cm{sup -2}). To our knowledge, such high methanol oxidation current densities have not been reported on any other non-platinum electrode in alkaline solution. Further, the modified electrodes are not poisoned by methanol oxidation intermediates/products. (author)

  14. Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films

    KAUST Repository

    Sun, Ke

    2015-03-11

    Reactively sputtered nickel oxide (NiOx) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O2(g). These NiOx coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silicon, crystalline n-type cadmium telluride, and hydrogenated amorphous silicon. Under anodic operation in 1.0 M aqueous potassium hydroxide (pH 14) in the presence of simulated sunlight, the NiOx films stabilized all of these self-passivating, high-efficiency semiconducting photoelectrodes for >100 h of sustained, quantitative solar-driven oxidation of water to O2(g). © 2015, National Academy of Sciences. All rights reserved.

  15. Layered lithium manganese(0.4) nickel(0.4) cobalt(0.2) oxide(2) as cathode for lithium batteries

    Science.gov (United States)

    Ma, Miaomiao

    The lithium ion battery occupies a dominant position in the portable battery market today. Intensive research has been carried out on every part of the battery to reduce cost, avoid environmental hazards, and improve battery performance. The commercial cathode material LiCoO2 has been partially replaced by LiNiyCo1- yO2 in the last two years, and mixed metal oxides have been introduced in the last quarter. From a resources point of view, only about 10 million tons of cobalt deposits are available from the world's minerals. However, there is about 500 times more manganese available than cobalt. Moreover, cobalt itself is not environmentally friendly. The purpose of this work is to find a promising alternative cathode material that can maintain good cycling performance, while at the same time reducing the cost and toxicity. When the cost is lowered, it is then possible to consider the larger scale use of lithium ion batteries in application such as hybrid electric vehicles (HEV). The research work presented in this thesis has focused on a specific composition of a layered lithium transition metal oxide, LiMn0.4Ni 0.4Co0.2O2 with the R3¯m structure. The presence of cobalt plays a critical role in minimizing transition metal migration to the lithium layer, and perhaps also in enhancing the electronic conductivity; however, cobalt is in limited supply and it is therefore more costly than nickel or manganese. The performance of LiMn0.4Ni0.4Co 0.2O2 was investigated and characterized utilizing various techniques an its performance compared with cobalt free LiMn0.5N i0.5O2, as well as with LiMn1/3Ni1/3Co 1/3O2, which is the most extensively studied replacement candidate for LiNiyCo1- yO2, and may be in SONY'S new hybrid cells. First, the structure and cation distribution in LiMn0.4Ni 0.4Co0.2O2 was studied by a combination of X-ray and neutron diffraction experiments. This combination study shows that about 3--5% nickel is present in the lithium layer, while manganese and

  16. Synthesis cathode material LiNi0.80Co0.15Al0.05O2 with two step solid-state method under air stream

    Science.gov (United States)

    Xia, Shubiao; Zhang, Yingjie; Dong, Peng; Zhang, Yannan

    2014-01-01

    A facile generic strategy of solid-state reaction under air atmosphere is employed to prepare LiNi0.8Co0.15Al0.05O2 layer structure micro-sphere as cathodes for Li-ion batteries. The impurity phase has been eliminated wholly without changing the R-3m space group of LiNi0.8Co0.15Al0.05O2. The electrochemical performance of LiNi0.8Co0.15Al0.05O2 cathodes depend on the sintering step, temperature, particle size and uniformity. The sample pre-sintered at 540 °C for 12 h and then sintered at 720 °C for 28 h exhibits the best electrochemical performance, which delivers a reversible capacity of 180.4, 165.8, 154.7 and 135.6 mAhg-1 at 0.2 C, 1 C, 2 C and 5 C, respectively. The capacity retention keeps over 87% after 76 cycles at 1 C. This method is simple, cheap and mass-productive, and thus suitable to large scale production of NCA cathodes directly used for lithium ion batteries.

  17. Microwave-assisted hydrothermal synthesis of coralloid nanostructured nickel hydroxide hydrate and thermal conversion to nickel oxide

    International Nuclear Information System (INIS)

    Lai, Teh-Long; Lai, Yuan-Lung; Yu, Jen-Wei; Shu, Youn-Yuen; Wang, Chen-Bin

    2009-01-01

    Coralloid nanostructured nickel hydroxide hydrate has been successfully synthesized by a simple microwave-assisted hydrothermal process using nickel sulfate hexahydrate as precursor and urea as hydrolysis-controlling agent. A pure coralloid nanostructured nickel oxide can be obtained from the nickel hydroxide hydrate after calcination at 400 deg. C. The thermal property, structure and morphology of samples were characterized by thermogravimetry (TG), temperature-programmed reduction (TPR), X-ray (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  18. Microwave-assisted hydrothermal synthesis of coralloid nanostructured nickel hydroxide hydrate and thermal conversion to nickel oxide

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Teh-Long [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Lai, Yuan-Lung [Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua 515, Taiwan (China); Yu, Jen-Wei [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Shu, Youn-Yuen, E-mail: shuyy@nknucc.nknu.edu.tw [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Wang, Chen-Bin, E-mail: chenbin@ccit.edu.tw [Department of Applied Chemistry and Materials Science, Chung Cheng Institute of Technology, National Defense University, Tahsi, Taoyuan 335, Taiwan (China)

    2009-10-15

    Coralloid nanostructured nickel hydroxide hydrate has been successfully synthesized by a simple microwave-assisted hydrothermal process using nickel sulfate hexahydrate as precursor and urea as hydrolysis-controlling agent. A pure coralloid nanostructured nickel oxide can be obtained from the nickel hydroxide hydrate after calcination at 400 deg. C. The thermal property, structure and morphology of samples were characterized by thermogravimetry (TG), temperature-programmed reduction (TPR), X-ray (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  19. Carbon deposition and sulfur poisoning during CO2 electrolysis in nickel-based solid oxide cell electrodes

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Blennow, Peter; Hjelm, Johan

    2017-01-01

    is investigated systematically using simple current-potential experiments. Due to variations of local conditions, it is shown that higher current density and lower fuel electrode porosity will cause local carbon formation at the electrochemical reaction sites despite operating with a CO outlet concentration...... outside the thermodynamic carbon formation region. Attempts at mitigating the issue by coating the composite nickel/yttria-stabilized zirconia electrode with carbon-inhibiting nanoparticles and by sulfur passivation proved unsuccessful. Increasing the fuel electrode porosity is shown to mitigate......Reduction of CO2 to CO and O2 in the solid oxide electrolysis cell (SOEC) has the potential to play a crucial role in closing the CO2 loop. Carbon deposition in nickel-based cells is however fatal and must be considered during CO2 electrolysis. Here, the effect of operating parameters...

  20. Nonlinear oxidation kinetics of nickel cermets

    International Nuclear Information System (INIS)

    Galinski, Henning; Bieberle-Huetter, Anja; Rupp, Jennifer L.M.; Gauckler, Ludwig J.

    2011-01-01

    The oxidation of a cermet of screen-printed nickel (Ni) and gadolinia-doped ceria (CGO) with an approximate median porosity of 50 vol.% has been studied via in situ X-ray diffraction and focused ion beam nanotomography in the temperature range 773-848 K. The oxidation kinetics of Ni to NiO is found to be highly nonlinear with an apparent activation energy of 2.8(2) eV in this temperature range. The nonlinear oxidation kinetics found is in good agreement with theoretical works on oxide growth driven by nonlinear inbuilt fields. Stress-induced Kirkendall void formation has been identified as the physical process that enhances the oxidation of Ni/CGO cermets. Compressive stresses within the Ni matrix result from the thermal expansion mismatch of Ni and CGO and cause plastic deformation as they exceed the yield stress of the Ni matrix. The pore size distribution of Kirkendall voids formed has been measured by FIB nanotomography and shows a significant temperature dependence. It is shown that even one cycle of reoxidation changes irreversibly the microstructure of the cermet which can be interpreted as the onset and main contribution to the mechanical degradation of the cermet.

  1. Characterization and electrochemical performance of lithium-active titanium dioxide inlaid LiNi0.5Co0.2Mn0.3O2 material prepared by lithium residue-assisted method

    International Nuclear Information System (INIS)

    Li, Lingjun; Chen, Zhaoyong; Song, Liubin; Xu, Ming; Zhu, Huali; Gong, Li; Zhang, Kaili

    2015-01-01

    Highlights: • LiTiO 2 -inlaid LiNi 0.5 Co 0.2 Mn 0.3 O 2 is prepared by lithium residue-assisted method. • The unique inlaid architecture inherits the advantages of coating and doping. • LiTiO 2 inlaying enhances the pristine at high cyclability and rate properties. • Excess LiTiO 2 modification results in low Li + diffusion coefficient. • The 3 mol% LiTiO 2 inlaid sample exhibits the best electrochemical performance. - Abstract: The lithium residues are consumed as raw materials to in-situ synthesize the LiTiO 2 -inlaid LiNi 0.5 Co 0.2 Mn 0.3 O 2 composites. The effects of various LiTiO 2 contents on the morphology, structure, and electrochemical properties of LiNi 0.5 Co 0.2 Mn 0.3 O 2 materials are investigated in detail. Energy dispersive spectrometer mapping, high-resolution transmission electron microscopy and fast Fourier transform analysis confirm that the spherical particles of LiNi 0.5 Co 0.2 Mn 0.3 O 2 are completely coated by crystalline LiTiO 2 phase; X-ray diffraction, cross-section SEM and corresponding EDS results indicate that Ti ions are also doped into the bulk LiNi 0.5 Co 0.2 Mn 0.3 O 2 with gradient distribution. Electrochemical tests show that the LiTiO 2 -inlaid samples exhibit excellent reversible capacity, enhanced cyclability, superior lithium diffusion coefficient and rate properties. Specially, the 3 mol% LiTiO 2 inlaid sample maintains 153.7 mA h g −1 with 94.4% capacity retention after 100 cycles between 2.7–4.4 V at 1 C, take 30% advantage than that of the pristine one (118.2 mA h g −1 ). This improvement can be attributed to the removal of lithium residues and suitable LiTiO 2 inlaying. The absence of lithium residue is helpful to retard the decomposition of LiPF 6 . While, suitable LiTiO 2 inlaying can protect the bulk from directly contacting the electrolyte, buffer the volume change of core and shell during cycles, increase the surface electronic conductivity and offer a 3D path for Li + diffusion from the bulk to

  2. Atomic Layer Deposition of Al2O3-Ga2O3 Alloy Coatings for Li[Ni0.5Mn0.3Co0.2]O2 Cathode to Improve Rate Performance in Li-Ion Battery.

    Science.gov (United States)

    Laskar, Masihhur R; Jackson, David H K; Guan, Yingxin; Xu, Shenzhen; Fang, Shuyu; Dreibelbis, Mark; Mahanthappa, Mahesh K; Morgan, Dane; Hamers, Robert J; Kuech, Thomas F

    2016-04-27

    Metal oxide coatings can improve the electrochemical stability of cathodes and hence, their cycle-life in rechargeable batteries. However, such coatings often impose an additional electrical and ionic transport resistance to cathode surfaces leading to poor charge-discharge capacity at high C-rates. Here, a mixed oxide (Al2O3)1-x(Ga2O3)x alloy coating, prepared via atomic layer deposition (ALD), on Li[Ni0.5Mn0.3Co0.2]O2 (NMC) cathodes is developed that has increased electron conductivity and demonstrated an improved rate performance in comparison to uncoated NMC. A "co-pulsing" ALD technique was used which allows intimate and controlled ternary mixing of deposited film to obtain nanometer-thick mixed oxide coatings. Co-pulsing allows for independent control over film composition and thickness in contrast to separate sequential pulsing of the metal sources. (Al2O3)1-x(Ga2O3)x alloy coatings were demonstrated to improve the cycle life of the battery. Cycle tests show that increasing Al-content in alloy coatings increases capacity retention; whereas a mixture of compositions near (Al2O3)0.5(Ga2O3)0.5 was found to produce the optimal rate performance.

  3. Rapid in situ growth of oriented titanium-nickel oxide composite nanotubes arrays coated on a nitinol wire as a solid-phase microextraction fiber coupled to HPLC-UV.

    Science.gov (United States)

    Zhen, Qi; Zhang, Min; Song, Wenlan; Wang, Huiju; Wang, Xuemei; Du, Xinzhen

    2016-10-01

    An oriented titanium-nickel oxide composite nanotubes coating was in situ grown on a nitinol wire by direct electrochemical anodization in ethylene glycol with ammonium fluoride and water for the first time. The morphology and composition of the resulting coating showed that the anodized nitinol wire provided a titania-rich coating. The titanium-nickel oxide composite nanotubes coated fiber was used for solid-phase microextraction of different aromatic compounds coupled to high-performance liquid chromatography with UV detection. The titanium-nickel oxide composite nanotubes coating exhibited high extraction capability, good selectivity, and rapid mass transfer for weakly polar UV filters. Thereafter the important parameters affecting extraction efficiency were investigated for solid-phase microextraction of UV filters. Under the optimized conditions, the calibration curves were linear in the range of 0.1-300 μg/L for target UV filters with limits of detection of 0.019-0.082 μg/L. The intraday and interday precision of the proposed method with the single fiber were 5.3-7.2 and 5.9-7.9%, respectively, and the fiber-to-fiber reproducibility ranged from 6.3 to 8.9% for four fibers fabricated in different batches. Finally, its applicability was evaluated by the extraction and determination of target UV filters in environmental water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Hierarchical Mesoporous Zinc-Nickel-Cobalt Ternary Oxide Nanowire Arrays on Nickel Foam as High-Performance Electrodes for Supercapacitors.

    Science.gov (United States)

    Wu, Chun; Cai, Junjie; Zhang, Qiaobao; Zhou, Xiang; Zhu, Ying; Shen, Pei Kang; Zhang, Kaili

    2015-12-09

    Nickel foam supported hierarchical mesoporous Zn-Ni-Co ternary oxide (ZNCO) nanowire arrays are synthesized by a simple two-step approach including a hydrothermal method and subsequent calcination process and directly utilized for supercapacitive investigation for the first time. The nickel foam supported hierarchical mesoporous ZNCO nanowire arrays possess an ultrahigh specific capacitance value of 2481.8 F g(-1) at 1 A g(-1) and excellent rate capability of about 91.9% capacitance retention at 5 A g(-1). More importantly, an asymmetric supercapacitor with a high energy density (35.6 Wh kg(-1)) and remarkable cycle stability performance (94% capacitance retention over 3000 cycles) is assembled successfully by employing the ZNCO electrode as positive electrode and activated carbon as negative electrode. The remarkable electrochemical behaviors demonstrate that the nickel foam supported hierarchical mesoporous ZNCO nanowire array electrodes are highly desirable for application as advanced supercapacitor electrodes.

  5. Effect of overcharge on Li(Ni0.5Mn0.3Co0.2)O2/graphite lithium ion cells with poly(vinylidene fluoride) binder. III - Chemical changes in the cathode

    Science.gov (United States)

    Bareño, Javier; Dietz Rago, Nancy; Dogan, Fulya; Graczyk, Donald G.; Tsai, Yifen; Naik, Seema R.; Han, Sang-Don; Lee, Eungje; Du, Zhijia; Sheng, Yangping; Li, Jianlin; Wood, David L.; Steele, Leigh Anna; Lamb, Joshua; Spangler, Scott; Grosso, Christopher; Fenton, Kyle; Bloom, Ira

    2018-05-01

    1.5 Ah pouch cells based on Li(Ni0.5Mn0.3Co0.2)O2 cathodes and graphite anodes, both containing poly (vinylidene fluoride) (PVDF) binders, were systematically overcharged to 100, 120, 140, 160, 180, and 250% state of charge (SOC), at which point they vented. The cells were subsequently discharged to 0% SOC and disassembled under an inert atmosphere for characterization. A combination of X-ray photoelectron spectroscopy (XPS), scanning-electron microscopy (SEM), energy-dispersive spectroscopy (EDS), 6Li SSNMR, and X-ray diffraction (XRD) analysis of the NMC532 cathodes indicates the formation of a thin C- and O-rich cathode electrolyte interphase layer, progressive Li loss above 140% SOC, and retention of the bulk crystal structure at all states of charge.

  6. Amplification of the Ect2 proto-oncogene and over-expression of Ect2 mRNA and protein in nickel compound and methylcholanthrene-transformed 10T1/2 mouse fibroblast cell lines

    International Nuclear Information System (INIS)

    Clemens, Farrah; Verma, Rini; Ramnath, Jamuna; Landolph, Joseph R.

    2005-01-01

    Occupational exposure of humans to mixtures of insoluble and soluble nickel (Ni) compounds correlates with increased incidences of lung, sinus, and pharyngeal tumors. Specific insoluble Ni compounds are carcinogenic to animals by inhalation and induce morphological and neoplastic transformation of cultured rodent cells. Our objectives were to (1) understand mechanisms of nickel ion-induced cell transformation, hence carcinogenesis and (2) develop biomarkers of nickel ion exposure and nickel ion-induced cell transformation. We isolated mRNAs from green nickel oxide (NiO), crystalline nickel monosulfide (NiS), and 3-methylcholanthrene (MCA) transformed C3H/10T1/2 Cl 8 cell lines, and determined by mRNA differential display that nine mRNA fragments were differentially expressed between Ni transformed and non-transformed 10T1/2 cell lines. Fragment R2-5 was expressed at higher steady-state levels in the transformed cell lines. R2-5 had 100% sequence identity to part of the coding region of Ect2, a mouse proto-oncogene encoding a GDP-GTP exchange factor. The 3.9-kb Ect2 transcript was expressed at 1.6- to 3.6-fold higher steady-state levels in four Ni transformed, and in two MCA-transformed, cell lines. Ect2 protein was expressed at 3.0- to 4.5-fold higher steady-state levels in Ni-transformed and in MCA-transformed cell lines. The Ect2 gene was amplified by 3.5- to 10-fold in Ni transformed, and by 2.5- to 3-fold in MCA transformed cell lines. Binding of nickel ions to enzymes of DNA synthesis likely caused amplification of the Ect2 gene. Ect2 gene amplification and over-expression of Ect2 mRNA and protein can cause microtubule disassembly and cytokinesis, contributing to induction and maintenance of morphological, anchorage-independent, and neoplastic transformation of these cell lines. Over-expression of Ect2 protein is a useful biomarker to detect exposure to nickel compounds and nickel ion-induced morphological and neoplastic cell transformation

  7. 2D nickel oxide nanosheets with highly porous structure for high performance capacitive energy storage

    Science.gov (United States)

    Li, Zijiong; Zhang, Weiyang; Liu, Yanyue; Guo, Jinjin; Yang, Baocheng

    2018-01-01

    Developing advanced electrochemical electrode materials with excellent performance is critical to their future energy storage devices. Herein, we design and synthesize two-dimensional (2D) porous structure nickel oxide (NiO) nanosheets via a facile and scalable hydrothermal approach, and further heating. The effects of heating time on the electrochemical performances are investigated. The results indicate that the maximum specific capacitance is achieved for NiO nanosheets when heating temperature and time are 300 °C and 3 h, respectively (namely NiO-3). The as-prepared NiO-3 nanosheet are grown uniform on the skeleton of reduced graphene oxide (rGO). The optimum NiO/rGO displays a reversible discharge capacity of 781.7 F g-1 at 1 A g-1, and shows an ultra-long life-span with over 94% capacitance retention after 4000 cycles. The enhanced electrochemical properties for NiO/rGO can be ascribed to a collaborative effect between NiO and rGO, which possess high capacitance storage ability and excellent conductivity, respectively.

  8. The preparation and role of Li_2ZrO_3 surface coating LiNi_0_._5Co_0_._2Mn_0_._3O_2 as cathode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Xu, Yue; Liu, Yang; Lu, Zhongpei; Wang, Haiying; Sun, Deqin; Yang, Gang

    2016-01-01

    Graphical abstract: LiNi_0_._5Co_0_._2Mn_0_._3O_2 is coated by Li_2ZrO_3 layer with the thickness about 20 nm. Li_2ZrO_3 coating effectively improves cycling performance and rate capability. LZO-LMO delivers 194 mAh g"−"1 at 0.2 C and presents improved cyclic performance at 55 °C. - Highlights: • LiNi_0_._5Co_0_._2Mn_0_._3O_2 is coated by Li_2ZrO_3 layer with the thickness about 20 nm. • Li_2ZrO_3 coating effectively improves cycling performance and rate capability. • LZO-LMO delivers 194 mAh g"−"1 at 0.2 C and presents improved cyclic performance at 55 °C. • Li_2ZrO_3 coating suppresses cation dissolution and enhances the structural stability. - Abstract: Li_2ZrO_3-coated LiNi_0_._5Co_0_._2Mn_0_._3O_2 (LZO-LMO) is successful synthesized by using a wet chemical method. Li_2ZrO_3 coating formed a uniform layer on LiNi_0_._5Co_0_._2Mn_0_._3O_2 particles (LMO) without changing the crystal structure. Cyclic voltammetry (CV) and charge–discharge tests show that the Li_2ZrO_3-modified layer can improve the cyclic and rate performance. In the cut-off voltage of 2.7–4.6 V, LZO-LMO maintains 86% of the initial capacity at the 50th cycle, which is much higher than LMO with the retention of 66% of the initial capacity. The coating layer of LZO plays the positive role in conductivity of lithium diffusion and improves rate performance of LMO. At 10 C rates, LZO-LMO delivers the initial capacity of 95 mAh g"−"1 which is much higher than 40 mAh g"−"1 delivered by LMO. At the environmental temperature of 55 °C, LZO-LMO delivers the initial capacity of 194 mAh g"−"1 at 0.2 C rate and presents an improved cyclic performance in comparison with LMO. The elemental analysis of electrodes carried out after 50 charge/discharge cycles shows minor Ni content deviation in LMO, but LZO-LMO still remains the stoichiometric ratio, because the Li_2ZrO_3 coating efficiently hinders the metal dissolution during charge/discharge.

  9. Sonochemical fabrication of petal array-like copper/nickel oxide composite foam as a pseudocapacitive material for energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Karthik, Namachivayam; Edison, Thomas Nesakumar Jebakumar Immanuel [School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Sethuraman, Mathur Gopalakrishnan, E-mail: mgsethu@gmail.com [Department of Chemistry, Gandhigram Rural Institute – Deemed University, Gandhigram, 624 302, Dindigul District, Tamil Nadu (India); Lee, Yong Rok, E-mail: yrlee@yu.ac.kr [School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

    2017-02-28

    Highlights: • A composite Ni foam textured with Cu particles was fabricated by a sonication method. • The foam can be used as a pseudocapacitive material for energy storage applications. • The foam has a high specific capacitance of 1773 F g{sup −1} at a scan rate of 5 mV s{sup −1}. - Abstract: Copper/nickel oxide composite foam (Cu/Ni) with petal array-like textures were successfully fabricated via a facile sonochemical approach, and its applications as a pseudocapacitive material for energy storage were examined. The nickel foam was immersed into a mixture of copper chloride (CuCl{sub 2}) and hydrochloric acid (HCl) and subsequently sonicated for 30 min at 60 °C. As a result of galvanic replacement, nickel was oxidized while copper was reduced, and the walls of the nickel foam were coated with copper particles. Studies using field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopic analyses confirmed the morphology and chemical structure of the as-obtained Cu/Ni oxide composite foam. The supercapacitive performance of the as-fabricated Cu/Ni oxide composite foam was evaluated in 2 M KOH by employing cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy analyses. Cyclic voltammograms revealed that the Cu/Ni oxide composite foam exhibited pseudocapacitive behavior and delivered a high specific capacitance of 1773 F g{sup −1} at a scan rate of 5 mV s{sup −1}. This improvement may be attributed to the morphology, surface functionalization with heteroatoms, hydrogen evolution, and high conductivity, along with the low resistance due to short path lengths for electron transportation.

  10. Thermal Oxidation of a Carbon Condensate Formed in High-Frequency Carbon and Carbon-Nickel Plasma Flow

    Science.gov (United States)

    Churilov, G. N.; Nikolaev, N. S.; Cherepakhin, A. V.; Dudnik, A. I.; Tomashevich, E. V.; Trenikhin, M. V.; Bulina, N. G.

    2018-02-01

    We have reported on the comparative characteristics of thermal oxidation of a carbon condensate prepared by high-frequency arc evaporation of graphite rods and a rod with a hollow center filled with nickel powder. In the latter case, along with different forms of nanodisperse carbon, nickel particles with nickel core-carbon shell structures are formed. It has been found that the processes of the thermal oxidation of carbon condensates with and without nickel differ significantly. Nickel particles with the carbon shell exhibit catalytic properties with respect to the oxidation of nanosized carbon structures. A noticeable difference between the temperatures of the end of the oxidation process for various carbon nanoparticles and nickel particles with the carbon shell has been established. The study is aimed at investigations of the effect of nickel nanoparticles on the dynamics of carbon condensate oxidation upon heating in the argon-oxygen flow.

  11. The acceleration intermediate phase (NiS and Ni3S2) evolution by nanocrystallization in Li/NiS2 thermal batteries with high specific capacity

    Science.gov (United States)

    Jin, Chuanyu; Zhou, Lingping; Fu, Licai; Zhu, Jiajun; Li, Deyi; Yang, Wulin

    2017-06-01

    The intermediate phase of NiS2 is thought to be a bottleneck currently to improve the overall performance of Li/NiS2 thermal batteries because of its low conductivity and close formation enthalpy between NiS2 and the intermediate phase (NiS, Ni3S2, etc). For improving the discharge performances of Li/NiS2 thermal batteries, the nano NiS2 with an average size of 85 ± 5 nm is designated as a cathode material. The electrochemical measurements show that the specific capacity of nano NiS2 cathode is higher than micro NiS2. The nano NiS2 cathode exhibits excellent electrochemical performances with high specific capacities of 794 and 654 mAh g-1 at current density of 0.1 and 0.5 A cm-2 under a cut-off voltage of 0.5 V, respectively. These results show that the rapid intermediate phase evolution from the nanocrystallization can obviously enhance use efficiency of NiS2 and improve discharge performances of thermal batteries.

  12. Hydrometallurgical process for the recovery of high value metals from spent lithium nickel cobalt aluminum oxide based lithium-ion batteries

    Science.gov (United States)

    Joulié, M.; Laucournet, R.; Billy, E.

    2014-02-01

    A hydrometallurgical process is developed to recover valuable metals of the lithium nickel cobalt aluminum oxide (NCA) cathodes from spent lithium-ion batteries (LIBs). Effect of parameters such as type of acid (H2SO4, HNO3 and HCl), acid concentration (1-4 mol L-1), leaching time (3-18 h) and leaching temperature (25-90 °C) with a solid to liquid ratio fixed at 5% (w/v) are investigated to determine the most efficient conditions of dissolution. The preliminary results indicate that HCl provides higher leaching efficiency. In optimum conditions, a complete dissolution is performed for Li, Ni, Co and Al. In the nickel and cobalt recovery process, at first the Co(II) in the leaching liquor is selectively oxidized in Co(III) with NaClO reagent to recover Co2O3, 3H2O by a selective precipitation at pH = 3. Then, the nickel hydroxide is precipitated by a base addition at pH = 11. The recovery efficiency of cobalt and nickel are respectively 100% and 99.99%.

  13. Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

    International Nuclear Information System (INIS)

    Gou Shiping; Sun, I.-W.

    2008-01-01

    The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

  14. The LiyNi0.2Mn0.2Co0.6O2 electrode materials: A structural and magnetic study

    International Nuclear Information System (INIS)

    Labrini, Mohamed; Saadoune, Ismael; Almaggoussi, Abdelmajid; Elhaskouri, Jamal; Amoros, Pedro

    2012-01-01

    Graphical abstract: EPR signal of the Li 0.6 Co 0.6 Ni 0.2 Mn 0.2 O 2 composition showing that Mn 4+ ions are the solely paramagnetic ions in the structure. Highlights: ► LiCo 0.6 Ni 0.2 Mn 0.2 O 2 was prepared by the combustion method with sucrose as a fuel. ► Chemical delithiaition was performed by using NO 2 BF 4 oxidizing agent. ► The rhombohedral symmetry was preserved upon lithium removal. ► Lithium extraction leads to Ni 2+ oxidation to Ni 4+ followed by Co 3+ oxidation. ► The EPR narrow signal of Li 0.6 Co 0.6 Ni 0.2 Mn 0.2 O 2 is due to the only active Mn 4+ ions. -- Abstract: Layered LiNi 0.2 Mn 0.2 Co 0.6 O 2 phase, belonging to a solid solution between LiNi 1/2 Mn 1/2 O 2 and LiCoO 2 most commercialized cathodes, was prepared via the combustion method at 900 °C for a short time (1 h). Structural and magnetic properties of this material during chemical extraction were investigated. The powders adopted the α-NaFeO 2 structure with almost none of the well-known Li/Ni cation disorder. The analysis of the magnetic properties in the paramagnetic domain agrees with the combination of Ni 2+ (S = 1), Co 3+ (S = 0) and Mn 4+ (S = 3/2) spin-only values. X-ray analysis of the chemically delithiated Li y Ni 0.2 Mn 0.2 Co 0.6 O 2 reveals no structural transition. The process of lithium extraction from and insertion into LiNi 0.2 Mn 0.2 Co 0.6 O 2 was discussed on the basis of ex situ EPR experiments and magnetic susceptibility. Oxidation of Ni 2+ (S = 1) to Ni 3+ (S = 1/2) and to Ni 4+ (S = 0) was observed upon lithium removal.

  15. Three-dimensional evaluation of compositional and structural changes in cycled LiNi1/3Co1/3Mn1/3O2 by atom probe tomography

    Science.gov (United States)

    Lee, Ji Yeong; Kim, Ji Yoon; Cho, Hae In; Lee, Chi Ho; Kim, Han Sung; Lee, Sang Uck; Prosa, Ty J.; Larson, David J.; Yu, Tae Hwan; Ahn, Jae-Pyoung

    2018-03-01

    Accelerated capacity fading of LiNi1/3Co1/3Mn1/3O2 (NCM111) electrode by the chemical migration of lithium (Li) or transition metals (TMs), and surface reconstruction in the surface during electrochemical cycling were evaluated by correlative analysis of atom probe tomography (APT) and transmission electron microscopy (TEM). The cycled NCM111 showed a lack of Li at surface which provides the driving force for long-range Ni migration toward surface. A schematic model for phase transformation and the kinetics of TM migration within the layered structure by density functional theory (DFT) calculations was proposed. This study provides insights into capacity loss and voltage fade upon electrochemical charge-discharge process of NCM111 by measuring the variation of Li composition away from the surface.

  16. In situ photoelectrochemistry and Raman spectroscopic characterization on the surface oxide film of nickel electrode in 30 wt.% KOH solution

    International Nuclear Information System (INIS)

    Nan Junmin; Yang Yong; Lin Zugeng

    2006-01-01

    The oxide films of nickel electrode formed in 30 wt.% KOH solution under potentiodynamic conditions were characterized by means of electrochemical, in situ PhotoElectrochemistry Measurement (PEM) and Confocal Microprobe Raman spectroscopic techniques. The results showed that a composite oxide film was produced on nickel electrode, in which aroused cathodic or anodic photocurrent depending upon polarization potentials. The cathodic photocurrent at -0.8 V was raised from the amorphous film containing nickel hydroxide and nickel monoxide, and mainly attributed to the formation of NiO through the separation of the cavity and electron when laser light irradiates nickel electrode. With the potential increasing to more positive values, Ni 3 O 4 and high-valence nickel oxides with the structure of NiO 2 were formed successively. The composite film formed in positive potential aroused anodic photocurrent from 0.33 V. The anodic photocurrent was attributed the formation of oxygen through the cavity reaction with hydroxyl on solution interface. In addition, it is demonstrated that the reduction resultants of high-valence nickel oxides were amorphous, and the oxide film could not be reduced completely. A stable oxide film could be gradually formed on the surface of nickel electrode with the cycling and aging in 30 wt.% KOH solution

  17. Thermodynamic properties of compounds of Na2O with the oxides of chromium, nickel, and iron

    International Nuclear Information System (INIS)

    Shaiu, B.J.

    1976-10-01

    Results of emf measurements on Na 2 O solid electrolytes in binary compounds with Cr 2 O 3 , FeO, and NiO are presented along with thermodynamic properties of these compounds. It was found that reliable thermodynamic data for compounds of NaCrO 2 , Na 2 FeO 2 , NaFeO 2 , Na 2 NiO 2 , and NaNiO 2 at 500 to 800 0 can be obtained by using emf measurements with solid electrolyte cells. The pretreatment of heating the cells in a vacuum of 10 -2 torr at 500 0 C or above for about 12 hours causes the emf dependence on temperature to be very small. The measurements were carried out over the temperature range in which no phase transformations occurred, the ΔC/sub p/ for the compounds involved was reasonably considered as approximately zero. Linear emf-temperature plots were therefore expected for these cells and the equation of ΔG 0 /sub f/ was indeed valid for constant values of ΔH 0 /sub f/ and ΔS 0 /sub f/. The formation of compound NaCrO 2 is thermodynamically favorable in a sodium loop made of austenic stainless steels. The critical oxygen concentration for the formation of NaCrO 2 shows that it is stable in liquid sodium in temperature range from 400 to 1100 0 C and Cr 2 O 3 does not exist with the double oxide in liquid sodium. The existence temperature for (Na 2 O) 2 .FeO in equilibrium with oxygen saturated liquid sodium is 693 0 K or above, for Na 2 FeO 2 it is 1141 0 K or above and for NaFeO 2 it is greater than or equal to 1173 0 K. The double oxides of nickel with sodium oxide are much less stable than the iron double oxides and do therefore not exist in liquid sodium. The nickel in austenitic stainless steel shows the least attack by oxygen saturated liquid sodium

  18. X-ray diffraction on nanoparticles chromium and nickel oxides obtained by gelatin using synchrotron radiation

    International Nuclear Information System (INIS)

    Menezes, Alan Silva de; Medeiros, Angela Maria de Lemos; Miranda, Marcus Aurelio Ribeiro; Almeida, Juliana Marcela Abraao; Remedios, Claudio Marcio Rocha; Silva, Lindomar R.D. da; Gouveia, S.T.; Sasaki, Jose Marcos; Jardim, P.M.

    2003-01-01

    Full text: Cr 2 O 3 nanoparticles has many applications like green pigments, wear resistance, and coating materials for thermal protection. Several methods to produce chromium oxide nanoparticles have already been studied, gas condensation, laser induced pyrolysis, microwave plasma, sol-gel and gamma radiation methods. Many applications for this kind of material can be provide concerning the particle size. For instance, particle size approximately of 200 nm are preferable as pigment due to its opacity and below 50 nm can be used as transparent pigment. In this work we have demonstrated that chromium and nickel oxide nanoparticles can be prepared by gelatin method. X-Ray diffraction (XRD) show that mean particle size for chromium oxide of 15-150 nm and nickel oxide of 90 nm were obtained for several temperature of sintering. The X-Ray powder diffraction pattern were performed using Synchrotron Radiation X-Ray source at XRD1 beamline in National Laboratory of Light Synchrotron (LNLS). (author)

  19. Combination of Asymmetric Supercapacitor Utilizing Activated Carbon and Nickel Oxide with Cobalt Polypyridyl-Based Dye-Sensitized Solar Cell

    International Nuclear Information System (INIS)

    Bagheri, Narjes; Aghaei, Alireza; Ghotbi, Mohammad Yeganeh; Marzbanrad, Ehsan; Vlachopoulos, Nick; Häggman, Leif; Wang, Michael; Boschloo, Gerrit; Hagfeldt, Anders; Skunik-Nuckowska, Magdalena; Kulesza, Pawel J.

    2014-01-01

    Highlights: • Dye Solar Cell and supercapacitor are integrated into a single device capable of generation and storage of energy. • The solar cell part of the device utilizes the Co-based electrolyte and nickel/PEDOT counter electrode. • A cobalt-doped nickel oxide together with activated carbon is used in the capacitor part of the device. • The integrated photocapacitor is characterized by the capacitance of 32 F g −1 and the total efficiency of 0.6%. - Abstract: A dye-sensitized solar cell (DSC) based on the metal-free organic sensitizer and the cobalt (II, III) polypyridyl electrolyte was integrated here within an asymmetric supercapacitor utilizing cobalt-doped nickel oxide and activated carbon as positive and negative electrodes, respectively. A low cost nickel foil served as intermediate (auxiliary) bifunctional electrode separating two parts of the device and permitting the DSC electrolyte regeneration at one side and charge storage within cobalt-doped nickel oxide at the other. The main purpose of the research was to develop an integrated photocapacitor system capable of both energy generation and its further storage. Following irradiation at the 100 mW cm −2 level, the solar cell generated an open-circuit voltage of 0.8 V and short-circuit current of 8 mA cm −2 which corresponds to energy conversion efficiency of 4.9%. It was further shown that upon integration with asymmetric supercapacitor, the photogenerated energy was directly injected into porous charge storage electrodes thus resulting in specific capacitance of 32 F g −1 and energy density of 2.3 Wh kg −1 . The coulumbic and total (energy conversion and charge storage) efficiency of photocapacitor were equal to 54% and 0.6%, respectively

  20. A PUFA-rich diet improves fat oxidation following saturated fat-rich meal.

    Science.gov (United States)

    Stevenson, Jada L; Miller, Mary K; Skillman, Hannah E; Paton, Chad M; Cooper, Jamie A

    2017-08-01

    To determine substrate oxidation responses to saturated fatty acid (SFA)-rich meals before and after a 7-day polyunsaturated fatty acid (PUFA)-rich diet versus control diet. Twenty-six, normal-weight, adults were randomly assigned to either PUFA or control diet. Following a 3-day lead-in diet, participants completed the pre-diet visit where anthropometrics and resting metabolic rate (RMR) were measured, and two SFA-rich HF meals (breakfast and lunch) were consumed. Indirect calorimetry was used to determine fat oxidation (Fox) and energy expenditure (EE) for 4 h after each meal. Participants then consumed a PUFA-rich diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 21 % of total energy was PUFA) or control diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 7 % of total energy was PUFA) for the next 7 days. Following the 7-day diet, participants completed the post-diet visit. From pre- to post-PUFA-rich diet, there was no change in RMR (16.3 ± 0.8 vs. 16.4 ± 0.8 kcal/20 min) or in incremental area under the curve for EE (118.9 ± 20.6-126.9 ± 14.1 kcal/8h, ns). Fasting respiratory exchange ratio increased from pre- to post-PUFA-rich diet only (0.83 ± 0.1-0.86 ± 0.1, p diet (0.03 ± 0.1-0.23 ± 0.1 g/15 min for cumulative Fox; p diet initiates greater fat oxidation after eating occasional high SFA meals compared to a control diet, an effect achieved in 7 days.

  1. The effect of CTAB on synthesis in butanol of samaria and gadolinia doped ceria - nickel oxide ceramics

    International Nuclear Information System (INIS)

    Arakaki, A.R.; Cunha, S.M.; Yoshito, W.K.; Ussui, V.; Lazar, D.R.R.

    2011-01-01

    In this work it was synthesized doped ceria and Samaria gadolinia - nickel oxide ceramics, mainly applied as anodes Fuel Cells Solid Oxide. Powders of composition Ce 0,8 (SmGd) 0,2 O 1,9 /NiO and mass ratio of 40: 60% were initially synthesized by hydroxides coprecipitation and then treated solvo thermically in butanol. Cerium samarium, gadolinium and nickel chlorides and CTAB with molar ratio metal / CTAB ranging from 1 to 3, were used as raw materials Powders were treated in butanol at 150 deg C for 16h. The powders were analyzed by X-ray diffraction, scanning electron microscopy, specific surface area for adsorption of nitrogen and particle size distribution by laser beam scattering. The ceramics were analyzed by scanning electron microscopy and density measurements by immersion technique in water. The results showed that the powders had the characteristic crystalline structures of ceria and nickel hydroxide, and high specific surface area (80 m 2 / g). The characterizations of ceramics demonstrated high chemical homogeneity and porosity values of 30%. (author)

  2. Nickel cobalt oxide nanowire-reduced graphite oxide composite material and its application for high performance supercapacitor electrode material.

    Science.gov (United States)

    Wang, Xu; Yan, Chaoyi; Sumboja, Afriyanti; Lee, Pooi See

    2014-09-01

    In this paper, we report a facile synthesis method of mesoporous nickel cobalt oxide (NiCo2O4) nanowire-reduced graphite oxide (rGO) composite material by urea induced hydrolysis reaction, followed by sintering at 300 degrees C. P123 was used to stabilize the GO during synthesis, which resulted in a uniform coating of NiCo2O4 nanowire on rGO sheet. The growth mechanism of the composite material is discussed in detail. The NiCo2O4-rGO composite material showed an outstanding electrochemical performance of 873 F g(-1) at 0.5 A g(-1) and 512 F g(-1) at 40 A g(-1). This method provides a promising approach towards low cost and large scale production of supercapacitor electrode material.

  3. Hot-Fire Test Results of Liquid Oxygen/RP-2 Multi-Element Oxidizer-Rich Preburners

    Science.gov (United States)

    Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.; Hulka, J. R.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. To supply the oxidizer-rich combustion products to the main injector of the integrated test article, existing subscale preburner injectors from a previous NASA-funded oxidizer-rich staged combustion engine development program were utilized. For the integrated test article, existing and newly designed and fabricated inter-connecting hot gas duct hardware were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. However, before one of the preburners was used in the integrated test article, it was first hot-fire tested at length to prove it could provide the hot exhaust gas mean temperature, thermal uniformity and combustion stability necessary to perform in the integrated test article experiment. This paper presents results from hot-fire testing of several preburner injectors in a representative combustion chamber with a sonic throat. Hydraulic, combustion performance, exhaust gas thermal uniformity, and combustion stability data are presented. Results from combustion stability modeling of these test results are described in a companion paper at this JANNAF conference, while hot-fire test results of the preburner injector in the integrated test article are described in another companion paper.

  4. Oxidation behaviour of plutonium rich (U, Pu)C and (U, Pu)O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Sali, S.K., E-mail: sksali@barc.gov.in [Fuel Chemistry Division (India); Kulkarni, N.K.; Phatak, Rohan [Fuel Chemistry Division (India); Agarwal, Renu [Product Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-10-15

    Oxidation behaviour of (U{sub 0.3}Pu{sub 0.7})C{sub 1.06} was investigated in air by heating samples up to 1073 K and 1273 K. Thermogravimetry (TG) of the samples and X-ray powder diffraction (XRD) of the intermediate products were used to understand the phenomenon taking place during this process. Theoretical calculations were carried out to understand the multiple phase changes taking place during oxidation of carbide. Theoretical results were validated by XRD analysis of the products obtained at different stages of oxidation. The final oxidized products were found to be a single FCC phase with O/M = 2.15 (M = U + Pu). Oxidation kinetic studies of (U{sub 0.3}Pu{sub 0.7})O{sub 2} and (U{sub 0.47}Pu{sub 0.53})O{sub 2} were carried out in dry air, using thermogravimetry, under non-isothermal conditions. The activation energy of oxidation was found to be 49 and 70 kJ/mol, respectively. Lattice parameter dependence on Pu/M and O/M of plutonium rich mixed oxide (MOX) was established using combined results of XRD and TG analysis of (U{sub 0.3}Pu{sub 0.7})O{sub 2+x} and (U{sub 0.47}Pu{sub 0.53})O{sub 2+x}.

  5. Ion-exchange mechanism of layered transition-metal oxides: case study of LiNi(0.5)Mn(0.5)O₂.

    Science.gov (United States)

    Gwon, Hyeokjo; Kim, Sung-Wook; Park, Young-Uk; Hong, Jihyun; Ceder, Gerbrand; Jeon, Seokwoo; Kang, Kisuk

    2014-08-04

    An ion-exchange process can be an effective route to synthesize new quasi-equilibrium phases with a desired crystal structure. Important layered-type battery materials, such as LiMnO2 and LiNi(0.5)Mn(0.5)O2, can be obtained through this method from a sodium-containing parent structure, and they often show electrochemical properties remarkably distinct from those of their solid-state synthesized equivalents. However, while ion exchange is generally believed to occur via a simple topotactic reaction, the detailed phase transformation mechanism during the process is not yet fully understood. For the case of layered LiNi(0.5)Mn(0.5)O2, we show through ex situ X-ray diffraction (XRD) that the ion-exchange process consists of several sequential phase transformations. By a study of the intermediate phase, it is shown that the residual sodium ions in the final structure may greatly affect the electrochemical (de)lithiation mechanism.

  6. PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3 ...

    African Journals Online (AJOL)

    degree of crystallinity give rise to reversible nickel incorporation. Pellets ... are of interest in solid oxide fuel cell and this is one of the features which make them attractive ... oxide system can only be obtained in a limited composition extent.

  7. 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.

  8. In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy

    KAUST Repository

    LAGROW, A.P.

    2017-08-29

    Understanding the oxidation and reduction mechanisms of transition metals, such as nickel (Ni), is important for their use in industrial applications of catalysis. A powerful technique for investigating the redox reactive species is in situ environmental transmission electron microscopy (ETEM), where oxidation and reduction can be tracked in real time. One particular difficulty in understanding the underlying reactions is understanding the underlying morphology of the starting structure in a reaction, in particular the defects contained in the material, and the exposed surface facets. Here-in, we use a colloidal nanoparticle synthesis in a continuous flow reactor to form nanoplates of nickel coated with oleylamine as a capping agent. We utilise an in situ heating procedure at 300 °C in vacuum to remove the oleylamine ligands, and then oxidise the Ni nanoparticles at 25 °C with 2 Pa oxygen, and follow the nanoparticles initial oxidation. After that, the nanoparticles are oxidised at 200 and 300 °C, making the size of the oxide shell increase to ∼4 nm. The oxide shell could be reduced under 2 Pa hydrogen at 500 °C to its initial size of ∼1 nm. High temperature oxidation encouraged the nanoparticles to form pure NiO nanoparticles, which occurred via the Kirkendall effect leading to hollowing and void formation.

  9. In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy

    KAUST Repository

    LAGROW, A.P.; AlYami, Noktan; LLOYD, D.C.; Bakr, Osman; BOYES, E.D.; GAI, P.L.

    2017-01-01

    Understanding the oxidation and reduction mechanisms of transition metals, such as nickel (Ni), is important for their use in industrial applications of catalysis. A powerful technique for investigating the redox reactive species is in situ environmental transmission electron microscopy (ETEM), where oxidation and reduction can be tracked in real time. One particular difficulty in understanding the underlying reactions is understanding the underlying morphology of the starting structure in a reaction, in particular the defects contained in the material, and the exposed surface facets. Here-in, we use a colloidal nanoparticle synthesis in a continuous flow reactor to form nanoplates of nickel coated with oleylamine as a capping agent. We utilise an in situ heating procedure at 300 °C in vacuum to remove the oleylamine ligands, and then oxidise the Ni nanoparticles at 25 °C with 2 Pa oxygen, and follow the nanoparticles initial oxidation. After that, the nanoparticles are oxidised at 200 and 300 °C, making the size of the oxide shell increase to ∼4 nm. The oxide shell could be reduced under 2 Pa hydrogen at 500 °C to its initial size of ∼1 nm. High temperature oxidation encouraged the nanoparticles to form pure NiO nanoparticles, which occurred via the Kirkendall effect leading to hollowing and void formation.

  10. Characteristics of LiMO2 (M = Co, Ni, Ni0.2Co0.8, Ni0.8Co0.2) powders prepared from solution of their acetates

    International Nuclear Information System (INIS)

    Arof, A.K.

    2008-01-01

    Stoichiometric quantities of the acetates of lithium, cobalt and nickel were dissolved in distilled water and stirred with a magnetic stirrer. After complete dissolution was obtained, the solutions were heated at 120 deg. C under continuous stirring until some dark colored powder materials were formed. These precursor materials were divided into three batches and heated at 250 deg. C (for 24 h), 370 deg. C (for 24 h) and 800 deg. C for 10 h. The precursor and calcined samples were X-rayed. The X-ray diffractograms for the prepared samples were compared to that of commercialized samples and those published in the literature. The Bragg peak with Miller indices (0 0 3) in the diffractogram of the LiNi 0.8 Co 0.2 O 2 prepared sample showed a lower intensity compared to the (1 0 4) peak. The ratio of the (0 0 3) to (1 0 4) peaks for the LiNi 0.2 Co 0.8 O 2 sample is 1.56. Lattice parameters showed that the LiCoO 2 and LiNi 0.2 Co 0.8 O 2 samples produced by the method in the present investigation have potential to exhibit good electrochemical performance when used as electrodes in lithium ion batteries

  11. Extra and intracellular synthesis of nickel oxide nanoparticles mediated by dead fungal biomass.

    Directory of Open Access Journals (Sweden)

    Marcia Regina Salvadori

    Full Text Available The use of dead biomass of the fungus Hypocrea lixii as a biological system is a new, effective and environmentally friendly bioprocess for the production and uptake of nickel oxide nanoparticles (NPs, which has become a promising field in nanobiotechnology. Dead biomass of the fungus was successfully used to convert nickel ions into nickel oxide NPs in aqueous solution. These NPs accumulated intracellularly and extracellularly on the cell wall surface through biosorption. The average size, morphology and location of the NPs were characterized by transmission electron microscopy, high-resolution transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The NPs were mainly spherical and extra and intracellular NPs had an average size of 3.8 nm and 1.25 nm, respectively. X-ray photoelectron spectroscopy analysis confirmed the formation of nickel oxide NPs. Infrared spectroscopy detected the presence of functional amide groups, which are probable involved in particle binding to the biomass. The production of the NPs by dead biomass was analyzed by determining physicochemical parameters and equilibrium concentrations. The present study opens new perspectives for the biosynthesis of nanomaterials, which could become a potential biosorbent for the removal of toxic metals from polluted sites.

  12. Hydrogen-rich medium protects mouse embryonic fibroblasts from oxidative stress by activating LKB1-AMPK-FoxO1 signal pathway.

    Science.gov (United States)

    Lee, Jihyun; Yang, Goowon; Kim, Young-Joo; Tran, Quynh Hoa; Choe, Wonchae; Kang, Insug; Kim, Sung Soo; Ha, Joohun

    2017-09-23

    Persistent oxidative stress is recognized as a major cause of many pathological conditions as well as ageing. However, most clinical trials of dietary antioxidants have failed to produce successful outcomes in treating oxidative stress-induced diseases. Molecular hydrogen (H 2 ) has recently received considerable attention as a therapeutic agent owing to its novel antioxidant properties, a selective scavenger of hydroxyl and peroxynitrite radicals. Beyond this, numerous reports support that H 2 can modulate the activity of various cellular signal pathways. However, its effect on AMP-activated protein kinase (AMPK) signal pathway, a central regulator of energy hemostasis, has remained almost elusive. Here, we report that hydrogen-rich medium activated LKB1-AMPK signal pathway without ATP depletion, which in turn induced FoxO1-dependent transcription of manganese superoxide dismutase and catalase in mouse embryonic fibroblasts. Moreover, hydrogen-rich media effectively reduced the level of reactive oxygen species in cells treated with hydrogen peroxide and protected these cells from apoptosis in an AMPK-dependent manner. These results suggest that the LKB1-AMPK-FoxO1 signaling pathway is a critical mediator of the antioxidant properties of H 2 , further supporting the idea that H 2 acts as a signaling molecule to serve various physiological functions. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Thermogravimetric study of the reduction of oxides of nickel and chromium

    Science.gov (United States)

    Herbell, T. P.

    1973-01-01

    The effectiveness of hydrogen, carbon and hydrogen-carbon in reducing NiO, Cr2O3, mixed NiO-Cr2O3 and oxidized Ni-20Cr was evaluated by thermogravimetry. NiO was effectively reduced by all three atmospheres, Cr2O3 only by hydrogen-carbon, NiO-Cr2O3 by hydrogen and hydrogen-carbon and oxidized Ni-20Cr by hydrogen, hydrogen-carbon and partially by carbon alone. The results indicate that nickel and carbon promote the reduction of Cr2O3.

  14. Research@ARL: Energy & Energetics

    Science.gov (United States)

    2012-06-01

    LiNi0.80Co0.15Al0.05O2 ( NCA ), cathode in a full cell, we found that the activation energy, Ea, for the charge transfer at the graphite/electrolyte interface...kinetics at the graphite anode and the lithium nickel cobalt aluminum oxide, LiNi0.80Co0.15Al0.05O2 ( NCA ), cathode in a full cell, we found that the...Both the NCA and the graphite electrodes are porous electrodes. The dimension of the NCA cathode was 6.35 cm × 3.81 cm, the dimension of the graphite

  15. SiO2-coated LiNi0.915Co0.075Al0.01O2 cathode material for rechargeable Li-ion batteries.

    Science.gov (United States)

    Zhou, Pengfei; Zhang, Zhen; Meng, Huanju; Lu, Yanying; Cao, Jun; Cheng, Fangyi; Tao, Zhanliang; Chen, Jun

    2016-11-24

    We reported a one-step dry coating of amorphous SiO 2 on spherical Ni-rich layered LiNi 0.915 Co 0.075 Al 0.01 O 2 (NCA) cathode materials. Combined characterization of XRD, EDS mapping, and TEM indicates that a SiO 2 layer with an average thickness of ∼50 nm was uniformly coated on the surface of NCA microspheres, without inducing any change of the phase structure and morphology. Electrochemical tests show that the 0.2 wt% SiO 2 -coated NCA material exhibits enhanced cyclability and rate properties, combining with better thermal stability compared with those of pristine NCA. For example, 0.2 wt% SiO 2 -coated NCA delivers a high specific capacity of 181.3 mA h g -1 with a capacity retention of 90.7% after 50 cycles at 1 C rate and 25 °C. Moreover, the capacity retention of this composite at 60 °C is 12.5% higher than that of pristine NCA at 1 C rate after 50 cycles. The effects of SiO 2 coating on the electrochemical performance of NCA are investigated by EIS, CV, and DSC tests, the improved performance is attributed to the surface coating layer of amorphous SiO 2 , which effectively suppresses side reactions between NCA and electrolytes, decreases the SEI layer resistance, and retards the growth of charge-transfer resistance, thus enhancing structural and cycling stability of NCA.

  16. Spinel LiNi0.5Mn1.5O4 as superior electrode materials for lithium-ion batteries: Ionic liquid assisted synthesis and the effect of CuO coating

    International Nuclear Information System (INIS)

    Li, Xueliang; Guo, Wei; Liu, Yunfu; He, Wenxiang; Xiao, Zhenghui

    2014-01-01

    The LiNi 0.5 Mn 1.5 O 4 with different morphologies have been successfully prepared through co-precipitation route in mixed solution containing 1-dodecyl-3-methylimidazolium bromide ([C 12 mim]Br) and H 2 O with different mass ratios and followed by a solid reaction at high temperature. The morphology of LiNi 0.5 Mn 1.5 O 4 varies with the increasing ratio of [C 12 mim]Br. These samples synthesized at three kinds of concentrations present flake-like morphology, agglomerated flake-like structure and polygon particles with size about 700 nm, respectively. The as-prepared LiNi 0.5 Mn 1.5 O 4 with polygon structure presents the highest discharge capacity. The optimal LiNi 0.5 Mn 1.5 O 4 sample was modified with 1, 3 and 5 wt.% CuO, respectively. The electrochemical testing results demonstrate 3 wt.% CuO-modified material had the capacity retention of higher than 95% after 100 cycles, and high capacity of 98.7 mAh g −1 at 10 C rate, in comparison with the capacity retention of 83% and capacity of 63.6 mAh g −1 for the pristine one. The remarkably improved rate performance and cycling stability can be attributed to CuO coating, which acts as an effective lithium-ion conductor and a protective material against corrosion from electrolyte

  17. Atom states and interatomic interactions in complex perovskite-like oxides. 4. Spin state of nickel(2) atoms in LaCa0.5Sr0.5NixAl1-xO4 solid solutions

    International Nuclear Information System (INIS)

    Chezhina, N.V.; Kuznetsova, I.V.

    1995-01-01

    Solid solutions of LaCa 0.5 Sr 0.5 Ni x Al 1-x O 4 (0≤x≤0.10) have been synthesized and their magnetic susceptibility in the temperature range of 77-400 K has been studied. The change in the basic state of nickel atoms in case of partial substitution of calcium for strontium atoms has been studied. The change in the basic state of nickel atoms in case of partial substitution of calcium for strontium atoms has been studied, as well as the way it affects exchange interaction in a complex oxide. It is shown that the substitution results in increase of the degree of paramagnetic atoms aggregation in solid solution. 9 refs., 2 figs., 1 tab

  18. High performance LiNi0.5Mn1.5O4 cathode by Al-coating and Al3+-doping through a physical vapor deposition method

    International Nuclear Information System (INIS)

    Sun, Peng; Ma, Ying; Zhai, Tianyou; Li, Huiqiao

    2016-01-01

    Highlights: • Metal Al was used as an electrical conductive coating material for LiNi 0.5 Mn 1.5 O 4 . • The uniform surface coating layer of metal Al was successfully achieved with adjusted thickness through a physical vapor deposition technology. • Al 3+ -doped LiNi 0.5 Mn 1.5 O 4 can be easily obtained by further directly annealing of Al-coated LiNi 0.5 Mn 1.5 O 4 in air. • The conductive Al-coating layer can greatly improve the rate performance and cycle stability of LiNi 0.5 Mn 1.5 O 4 . - Abstract: In this work, spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) hollow microspheres are synthesized by an impregnation method using microsphere MnO 2 as both the precursor and template. To enhance the electrical conductivity of LNMO, metal Al was employed for the first time as a coating material for LNMO. Though an Electron-beam Vapor Deposition approach, the surface of LNMO can be easily coated by a tight layer of Al nanoparticles with adjusted thickness. Further annealing the Al-coated sample at 800 °C in air, the Al 3+ -doped LNMO can be obtained. The effects of Al-coating and Al 3+ -doping on the sample morphology and structure are investigated by SEM, TEM, XRD and FT-IR. The electrochemical properties of Al-coated LNMO and Al 3+ -doped LNMO are measured with comparison of bare LNMO by charge/discharge tests and electrochemical impedance spectroscopy (EIS). The results show that both Al-coating and Al 3+ -doping can greatly enhance the cycle performance and rate capability of LNMO. Especially for Al-coated LNMO, it shows the lowest battery impedance due to the existence of conductive Al coating layer, thus delivers the best rate performance among the three. The physical coating procedure used in this work may provide a new facile modification approach for other cathode materials.

  19. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium

    International Nuclear Information System (INIS)

    Silva, M.L.A. da; Varela, M.C.R.S.

    2016-01-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  20. Catalytic properties of nickel ferrites for oxidation of glucose, β-nicotiamide adenine dinucleotide (NADH) and methanol

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, R. [Departamento de Química, Universidad de Guanajuato, Cerro de la Venada s/n, Pueblito de Rocha, C.P. 36040 Guanajuato, Gto (Mexico); Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco s/n, C.P. 28049 Madrid (Spain); Gutiérrez, S. [Departamento de Química, Universidad de Guanajuato, Cerro de la Venada s/n, Pueblito de Rocha, C.P. 36040 Guanajuato, Gto (Mexico); Menéndez, N. [Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco s/n, C.P. 28049 Madrid (Spain); Herrasti, P., E-mail: pilar.herrasti@uam.es [Departamento de Química Física Aplicada, Universidad Autónoma de Madrid, Cantoblanco s/n, C.P. 28049 Madrid (Spain)

    2014-02-15

    Highlights: ► NiFe{sub 2}O{sub 4} nanoparticles obtained by electrochemical method are effective catalyst. ► A partially inverse spinel was obtained with 57% Fe{sup 3+} in tetrahedral position. ► A non-enzymatic electrode using NiFe{sub 2}O{sub 4} nanoparticles has been manufactured. -- Abstract: Nickel ferrite nanoparticles (NiFe{sub 2}O{sub 4}) were synthesized by electrochemical method and used as catalyst for direct oxidation of glucose, NADH and methanol. Characterization of these nanoparticles was carried out by X-ray diffraction, Mössbauer spectroscopy, and colloidal properties such as hydrodynamic radius and Zeta potential. To evaluate the catalytic properties of these nanoparticles against the oxidation process, paste graphite electrodes mixing nickel ferrites and different conductive materials (graphite, carbon nanotubes) and binders agents (mineral oil, 1-octylpyridinium hexafluorophosphate (nOPPF6)) were used. The results prove good catalytic properties of these materials, with an oxidation potential around 0.75, 0.5 and 0.8 V for glucose, NADH, and methanol, respectively.

  1. Impact of morphological changes of LiNi1/3Mn1/3Co1/3O2 on lithium-ion cathode performances

    Science.gov (United States)

    Pierre-Etienne, Cabelguen; David, Peralta; Mikael, Cugnet; Pascal, Maillet

    2017-04-01

    Major advances in Li-ion battery technology rely on the nanostructuration of active materials to overcome the severe kinetics limitations of new - cheaper and safer - chemistries. However, opening porosities results in the decrease of volumetric performances, closing the door to significant applications such as portable electronics, electromobility, and grid storage. In this study, we analyze the link between morphologies and performances of model LiNi1/3Mn1/3Co1/3O2 materials. By quantifying exhaustively their microstructures using nitrogen adsorption, mercury intrusion porosimetry, and helium pycnometry, we can discuss how porosities and surface areas are linked to the electrochemical behavior. There is no geometrical parameters that can predict the performances of all our materials. The shape of agglomeration dictates the electrochemical behavior. A huge drop in volumetric performances is measured when microstructure is considered. We show that gravimetric and volumetric power performances are contrary to each other. Highly dense materials exhibit, by far, the best power performances in terms of volumetric figures, so that opening porosities might not be the best strategy, even in non-nanosized materials, for Li-ion battery technology.

  2. Preparation and supercapacitor application of the single crystal nickel hydroxide and oxide nanosheets

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qing [Department of Materials Science and Engineering, Yunnan University, 650091 Kunming (China); Ni, Haifang [Institute of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Cai, Yun; Cai, Xiaoyan [Department of Materials Science and Engineering, Yunnan University, 650091 Kunming (China); Liu, Yongjun [Advanced Analysis and Measurement Center, Yunnan University, 650091 Kunming (China); Chen, Gang [Department of Materials Science and Engineering, Yunnan University, 650091 Kunming (China); Fan, Li-Zhen, E-mail: fanlizhen@ustb.edu.cn [Institute of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Wang, Yude, E-mail: ydwang@ynu.edu.cn [Department of Materials Science and Engineering, Yunnan University, 650091 Kunming (China)

    2013-09-01

    Graphical abstract: The nickel hydroxide and nickel oxide nanosheets prepared using CTAB at room temperature exhibit a high specific capacitance, prompt charge/discharge rate. - Highlights: • The nickel hydroxide nanosheets were prepared using CTAB at room temperature. • Ni(OH){sub 2} nanosheet can be successfully converted to NiO nanosheet via calcination. • The NiO nanosheet has a specific capacitance of 388 F g{sup −1} at 5 A g{sup −1} in KOH solution. • Anneal temperature impacts capacitive properties as electrode. - Abstract: The single crystalline Ni(OH){sub 2} nanosheets were synthesized by a simple chemical precipitation method using nickel chloride as precursors and ammonia as precipitating agent. The Ni(OH){sub 2} nanosheets were successfully converted to NiO nanosheets via calcination under appropriate conditions. Analytical methods such as X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and Fourier transformed infrared (FTIR) spectra were employed to characterize the morphology and microstructure of the final products. The experimental results revealed that Ni(OH){sub 2} nanosheets were shape-preserved transformed to NiO nanosheets at 250 °C for 24 h. Ni(OH){sub 2} and NiO nanosheets were directly functionalized as supercapacitor electrodes for potential energy storage applications, whose charge–discharge properties, electrochemical impedance spectra, cyclic voltammetry, and cycle performance were examined. The experimental results show that the single-crystalline NiO nanosheets are a promising candidate for the supercapacitor electrode. They exhibit a high specific capacitance, prompt charge/discharge rate.

  3. Cytotoxicity and apoptotic effects of nickel oxide nanoparticles in cultured HeLa cells

    Directory of Open Access Journals (Sweden)

    Kezban Ada

    2010-04-01

    Full Text Available The aim of this study was to observe the cytotoxicity and apoptotic effects of nickel oxide nanoparticles on humancervix epithelioid carcinoma cell line (HeLa. Nickel oxide precursors were synthesized by an nickel sulphate-excess ureareaction in boiling aqueous solution. The synthesized NiO nanoparticles (<200 nm were investigated by X-ray diffractionanalysis and transmission electron microscopy techniques. For cytotoxicity experiments, HeLa cells were incubated in50-500 μg/mL NiO for 2, 6, 12 and 16 hours. The viable cells were counted with a haemacytometer using light microscopy.The cytotoxicity was observed low in 50-200 μg/mL concentration for 16 h, but high in 400-500 μg/mL concentration for2-6 h. HeLa cells' cytoplasm membrane was lysed and detached from the well surface in 400 μg/mL concentration NiOnanoparticles. Double staining and M30 immunostaining were performed to quantify the number of apoptotic cells in cultureon the basis of apoptotic cell nuclei scores. The apoptotic effect was observed 20% for 16 h incubation.

  4. Optical and structural characterization of nickel oxide-based thin films obtained by chemical bath deposition

    International Nuclear Information System (INIS)

    Vidales-Hurtado, M.A.; Mendoza-Galvan, A.

    2008-01-01

    Nickel oxide-based thin films were obtained using the chemical bath deposition method on glass and silicon substrates. The precursor solution used was a mixture of nickel nitrate, urea, and deionized water. Molar concentration of nickel (0.3-1.0 M), deposition time, and immersing cycles were considered as deposition variables. Infrared spectroscopy and X-ray diffraction data reveal that all as-deposited films correspond to the transparent turbostratic phase α(II)-Ni(OH) 2 . However, the rate of deposition depends on nickel content in the solution. After annealing in air at temperatures above of 300 deg. C, the films are transformed to the NiO phase and show a grey/black color. In these films, scanning electron microscopy images show aggregates of thin stacked sheets on their surface, such aggregates can be easily removed leaving only a thin NiO layer of about 30 nm adhered firmly to the substrate, regardless of nickel concentration in the solution and deposition time. In order to obtain thicker NiO films with good optical properties a procedure is developed performing several immersing-annealing cycles

  5. Steady-state growth of NiO scales on ceria-coated polycrystalline nickel

    International Nuclear Information System (INIS)

    Czerwinski, F.; Szpunar, J.A.; Smeltzer, W.W.

    1996-01-01

    The effect of CeO 2 ceramic coatings with thicknesses in the range of 14 to 42 nm on the oxidation of high purity polycrystalline nickel at 973 K in 1 atm O 2 has been studied. The ceria coatings decrease the Ni oxidation rate after 125 h by a factor up to 45, which is significantly higher than the reduction achieved during early stages. Growth features, including oxide thickness, surface morphology, and the texture for both the pure and CeO 2 modified NiO, demonstrate a definite dependence on the crystallographic orientation of the Ni substrate. Oxides with thicknesses of up to 1 microm developed on CeO 2 -coated Ni consisted of three sublayers. The Ce-rich part, composed of small NiO grains and CeO 2 particles, was located inside the scale and shifted deeper into the scale with increased oxidation time. The growth kinetics and microstructural evolutions of modified NiO are discussed in terms of the mechanism of inhibition of grain boundary diffusion in NiO by Ce +4 ions

  6. Extracellular synthesis and characterization of nickel oxide nanoparticles from Microbacterium sp. MRS-1 towards bioremediation of nickel electroplating industrial effluent.

    Science.gov (United States)

    Sathyavathi, S; Manjula, A; Rajendhran, J; Gunasekaran, P

    2014-08-01

    In the present study, a nickel resistant bacterium MRS-1 was isolated from nickel electroplating industrial effluent, capable of converting soluble NiSO4 into insoluble NiO nanoparticles and identified as Microbacterium sp. The formation of NiO nanoparticles in the form of pale green powder was observed on the bottom of the flask upon prolonged incubation of liquid nutrient medium containing high concentration of 2000ppm NiSO4. The properties of the produced NiO nanoparticles were characterized. NiO nanoparticles exhibited a maximum absorbance at 400nm. The NiO nanoparticles were 100-500nm in size with unique flower like structure. The elemental composition of the NiO nanoparticles was 44:39. The cells of MRS-1 were utilized for the treatment of nickel electroplating industrial effluent and showed nickel removal efficiency of 95%. Application of Microbacterium sp. MRS-1 would be a potential bacterium for bioremediation of nickel electroplating industrial waste water and simultaneous synthesis of NiO nanoparticles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Influence of coprecipitation and mechanical mixture methods on the characteristics of nickel oxide-alumina composites; Influencia dos metodos de coprecipitacao e mistura mecanica nas caracteristicas de compositos oxido de niquel-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, G.L.; Yoshito, W.K.; Ussui, V.; Lima, N.B. de; Lazar, D.R.R., E-mail: gcordeiro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2014-07-01

    Alumina-supported nickel catalysts are currently used in the reforming process due to low cost and high activity for hydrogen production from alcohols. In this work, the effect of preparation methods on nickel oxide-alumina based materials has been investigated. Nickel content was fixed at 15 wt%. Ceramic powders were obtained by coprecipitation in ammonia medium and mechanical mixture. Coprecipitated materials were calcined in air at 750 deg C to obtain the corresponding oxides. Materials obtained by mechanical mixture were prepared by wet milling of nickel oxide and alumina powders, both synthesized by precipitation and calcination in air at 450 and 750 deg C, respectively. Powders were characterized by X-ray diffraction, nitrogen gas sorption by applying the BET method, laser diffraction, scanning electron microscopy, electrophoretic mobility measurements for zeta potential determination and infrared spectroscopy. The results showed that coprecipitation method allowed the production of mixed oxides with high surface area (232,7 ± 3,2 m{sup 2}.g{sup -1}) and normal granulometric distribution while mechanical mixture led to the formation of materials constituted by gamma alumina and nickel oxide phases, with low surface area (136,2 ± 0,5 m{sup 2}.g{sup -1}) and bimodal granulometric distribution. (author)

  8. Orbital-Specific observation of O2p and Ni3d electrons in LiNi0.5Mn0.5O2, a cathode material for lithium-ion batteries

    Science.gov (United States)

    Satou, Yoshinori; Komine, Shigeki; Shimizu, Sumera

    2017-09-01

    Cathode materials for lithium-ion batteries containing Ni2+ have attracted much interest because of their high theoretical capacity. However, the precise electronic structures of these cathode materials have not yet been clearly observed, especially the energy positions of the O2p and Ni3d orbitals and the shape of the density of states. The aim of this study was to investigate the relative energy positions and shape of the density of states of O2p and Ni3d for LiNi0.5Mn0.5O2 experimentally. We cleaved a LiNi0.5Mn0.5O2 pellet in an Ar-filled glove box and performed synchrotron ultraviolet photoelectron spectroscopy for different photon energies, which enabled us to investigate the relative cross-section intensity of O2p and Ni3d. As a result, the valence-band structure was determined. We found that O2p electrons are itinerant and exist in the vicinity of the Fermi energy more than Ni3d electrons. Ni3d electrons are more localized and spread mainly from 1.2-1.5 eV below the Fermi energy. To validate the electronic structure, we measured the synchrotron O K-edge X-ray absorption fine structure of electrochemically lithium-extracted LiNi0.5Mn0.5O2. The electronic structure demonstrated that ligand holes in the oxygen atoms form below the Fermi level during the initial stage of Li extraction and that the formation rate of the holes decreases with Li extraction.

  9. Enhanced thermoelectric property of oxygen deficient nickel doped SnO2 for high temperature application

    Science.gov (United States)

    Paulson, Anju; Sabeer, N. A. Muhammad; Pradyumnan, P. P.

    2018-04-01

    Motivated by the detailed investigation on the thermoelectric performance of oxide materials our work concentrated on the influence of acceptor dopants and defect density in the lattice plane for the enhancement of thermoelectric power. The series of Sn1‑x Nix O2 (0.01 ≤ x ≤ 0.05) compositions were prepared by solid state reaction mechanism and found that 3 atomic percentage Ni doped SnO2 can be considered as a good candidate due to its promising electrical and transport properties. Defect lattices were introduced in the sample and the deviation from oxygen stochiometry was ensured using photoluminescence measurement. High power factor was obtained for the 3 atomic percentage nickel doped SnO2 due to the effective number of charge carrier concentration and the depletion of oxygen rich layers. Defect centered and acceptor doped SnO2 lattice opens a new door for energy harvesting at higher temperatures.

  10. Fabrication and Electrochemical Performance of LiNi0.5Co0.2Mn0.3O2 Coated with Nano FePO4 as Cathode Material for Lithium-ion Batteries

    Directory of Open Access Journals (Sweden)

    DONG Peng

    2017-11-01

    Full Text Available Layered LiNi0.5Co0.2Mn0.3O2 coated with homogeneous nano FePO4 suspension was prepared by using co-precipitation method. XRD, TG-DTA and TEM were adopted to characterize the structure, morphology and liquid state of FePO4 prepared. The structure, morphology and electrochemical performance of the coated materials prepared were characterized by the means such as XRD, SEM, EDS, TEM, ICP, galvanostatic charge-discharge cycling, cyclic voltammetry (CV and electrochemical impedance spectroscopy(EIS tests. The effect of heat treatment temperature and coating quantity on the structure and electrochemical performance of coated LiNi0.5Co0.2Mn0.3O2 by co-precipitation method was explored. The results show that 400℃ and 2%(mass fraction,the same below FePO4 coating can significantly improve cycle performance and rate capability of LiNi0.5Co0.2Mn0.3O2, CV and EIS testing results reveal that FePO4 coating can improve the reversibility and dynamic performance for LiNi0.5Co0.2Mn0.3O2. ICP results show that FePO4 coating layer can effectively reduce the electrolyte to dissolute and erode cathode materials, stabilize its layered structure, then improve the electrochemical performance of cathode materials.

  11. Synthesis and characterization of mesoporous materials for CO_2 capture: influence of nickel oxide

    International Nuclear Information System (INIS)

    Nascimento, Alexsandra Rodrigues do

    2014-01-01

    Several materials are currently under study for the CO_2 capture process, like the metal oxides and mixed metal oxides, zeolites, carbonaceous materials, metal-organic frameworks (MOF's) organosilica and modified silica surfaces. In this work, evaluated the adsorption capacity of CO_2 in mesoporous materials of different structures, such as MCM-48 and SBA-15 without impregnating and impregnated with nickel in the proportions 5 %, 10 % and 20 % (m/m), known as 5Ni-MCM-48, 10Ni-MCM-48, 20Ni-MCM-48 and 5Ni-SBA-15, 10Ni-SBA-15, 20Ni-SBA-15. The materials were characterized by means of X-ray diffraction (XRD), thermal analysis (TG and DTG), Fourier transform infrared spectroscopy (FT-IR), N_2 adsorption and desorption (BET) and scanning electron microscopy (SEM) with EDS. The adsorption process was performed varying the pressure of 100 - 4000 kPa and keeping the temperature constant and equal to 298 K. At a pressure of 100 kPa, higher concentrations of adsorption occurred for the materials 5Ni-MCM-48 (0.795 mmol g"-"1) and SBA-15 (0.914 mmol g"-"1) is not impregnated, and at a pressure of 4000 kPa for MCM-48 materials (14.89 mmol g"-"1) and SBA-15 (9.97 mmol g"-"1) not impregnated. The results showed that the adsorption capacity varies positively with the specific area, however, has a direct dependency on the type and geometry of the porous structure of channels. The data were fitted using the Langmuir and Freundlich models and were evaluated thermodynamic parameters Gibbs free energy and entropy of the adsorption system. (author)

  12. Nickel Oxide (NiO nanoparticles prepared by solid-state thermal decomposition of Nickel (II schiff base precursor

    Directory of Open Access Journals (Sweden)

    Aliakbar Dehno Khalaji

    2015-06-01

    Full Text Available In this paper, plate-like NiO nanoparticles were prepared by one-pot solid-state thermal decomposition of nickel (II Schiff base complex as new precursor. First, the nickel (II Schiff base precursor was prepared by solid-state grinding using nickel (II nitrate hexahydrate, Ni(NO32∙6H2O, and the Schiff base ligand N,N′-bis-(salicylidene benzene-1,4-diamine for 30 min without using any solvent, catalyst, template or surfactant. It was characterized by Fourier Transform Infrared spectroscopy (FT-IR and elemental analysis (CHN. The resultant solid was subsequently annealed in the electrical furnace at 450 °C for 3 h in air atmosphere. Nanoparticles of NiO were produced and characterized by X-ray powder diffraction (XRD at 2θ degree 0-140°, FT-IR spectroscopy, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The XRD and FT-IR results showed that the product is pure and has good crystallinity with cubic structure because no characteristic peaks of impurity were observed, while the SEM and TEM results showed that the obtained product is tiny, aggregated with plate-like shape, narrow size distribution with an average size between 10-40 nm. Results show that the solid state thermal decomposition method is simple, environmentally friendly, safe and suitable for preparation of NiO nanoparticles. This method can also be used to synthesize nanoparticles of other metal oxides.

  13. Advanced cathode materials for high-power applications

    Science.gov (United States)

    Amine, K.; Liu, J.; Belharouak, I.; Kang, S.-H.; Bloom, I.; Vissers, D.; Henriksen, G.

    In our efforts to develop low cost high-power Li-ion batteries with excellent safety, as well as long cycle and calendar life, lithium manganese oxide spinel and layered lithium nickel cobalt manganese oxide cathode materials were investigated. Our studies with the graphite/LiPF 6/spinel cells indicated a very significant degradation of capacity with cycling at 55 °C. This degradation was caused by the reduction of manganese ions on the graphite surface which resulted in a significant increase of the charge-transfer impedance at the anode/electrolyte interface. To improve the stability of the spinel, we investigated an alternative salt that would not generate HF acid that may attack the spinel. The alternative salt we selected for this work was lithium bisoxalatoborate, LiB(C 2O 4) 2 ("LiBoB"). In this case, the graphite/LiBoB/spinel Li-ion cells exhibited much improved cycle/calendar life at 55 °C and better abuse tolerance, as well as excellent power. A second system based on LiNi 1/3Co 1/3Mn 1/3O 2 layered material was also investigated and its performance was compared to commercial LiNi 0.8Co 0.15Al 0.05O 2. Cells based on LiNi 1/3Co 1/3Mn 1/3O 2 showed lower power fade and better thermal safety than the LiNi 0.8Co 0.15Al 0.05O 2-based commercial cells under similar test conditions. Li-ion cells based on the material with excess lithium (Li 1.1Ni 1/3Co 1/3Mn 1/3O 2) exhibited excellent power performance that exceeded the FreedomCAR requirements.

  14. Enhanced electrochemical performance of LiNi0.6Co0.2Mn0.2O2 cathode at high cutoff voltage by modifying electrode/electrolyte interface with lithium metasilicate

    International Nuclear Information System (INIS)

    Fu, Jiale; Mu, Daobin; Wu, Borong; Bi, Jiaying; Liu, Xiaojiang; Peng, Yiyuan; Li, Yiqing; Wu, Feng

    2017-01-01

    Highlights: •The electrochemical properties of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode are investigated at high voltage of 4.6 V. •The Li 2 SiO 3 suppresses the decomposition of LiPF 6 and carbonate solvents. •Li 2 SiO 3 helpfully retards the transition metal dissolution by consuming HF. •The enhanced electrochemical properties of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 cathode mixed with Li 2 SiO 3 . -- Abstract: Developing high-voltage Li ion batteries (LIBs) is an important trend to meet the requirement of high energy density battery. However, high voltage will cause a series of problems harming the cycle performance of LIBs at the same time. This work is to investigate the effect of inorganic substance Li 2 SiO 3 on the electrochemical performance of LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathode at high cutoff voltage of 4.6 V. XRD result shows that the structure of NCM622 cathode material is not affected by mixing Li 2 SiO 3 . However, XPS and EIS tests indicate that Li 2 SiO 3 has an evident influence on suppressing the decomposition of LiPF 6 and carbonate solvents at high voltage, reducing interfacial solid film impedance and modifying electrode/electrolyte interface. In addition, Li 2 SiO 3 retards the transition metal dissolution by consuming HF. Therefore, it enhances the electrochemical properties of the NCM622 cathode significantly. The highest discharge capacity increases to 191.7 mA h g -1 by mixing Li 2 SiO 3 , compared with the value of 180 mA h g -1 in the case of NCM622 cathode. The NCM622 electrode mixed with Li 2 SiO 3 also exhibits a better capacity retention of 73.4% after 200 cycles and a high rate capability at 20C with the value of 89 mA h g -1 , in contrast with 62.2% and 31 mA h g -1 attained in the NCM622 cathode.

  15. Contribution to the study of the oxidation reaction of the carbon oxide in contact with catalysts issued from the decomposition of nickel hydro-aluminates at various temperatures

    International Nuclear Information System (INIS)

    Samaane, Mikhail

    1966-01-01

    Addressing the study of the oxidation reaction of carbon oxide which produces carbon dioxide, this research thesis reports the study of this reaction in presence of catalysts (2NiO + Al 2 O 3 , NiAl 2 O 4 and NiO + NiAl 2 O 4 ) issued from the decomposition of nickel hydro-aluminates at different temperatures. The first part describes experimental techniques and the nature of materials used in this study. The second part reports the study of the catalytic activity of the 2NiO+Al 2 O 3 catalyst during the oxidation of CO. Preliminary studies are also reported: structure and texture of nickel hydro-aluminate which is the raw material used to produce catalysts, activation of this compound to develop the catalytic activity in CO oxidation, chemisorption of CO, O 2 and CO 2 on the 2NiO+Al 2 O 3 solid, interaction of adsorbed gases at the solid surface, and kinetic study of the oxidation reaction. The third part reports the study of the catalytic activity in the oxidation reaction of CO of spinel catalysts (NiAl 2 O 4 and NiO+NiAl 2 O 4 ) obtained by calcination of nickel hydro-aluminates at high temperature. The formation of the spinel phase, the chemisorption of CO, O 2 and CO 2 on NiAl 2 O 4 , and the kinetic of the oxidation reaction are herein studied

  16. In situ fabrication of nickel based oxide on nitrogen-doped graphene for high electrochemical performance supercapacitors

    Science.gov (United States)

    Pan, Denghui; Zhang, Mingmei; Wang, Ying; Yan, Zaoxue; Jing, Junjie; Xie, Jimin

    2017-10-01

    In this article, we synthesize Ni(OH)2 homogeneous grown on nitrogen-doped graphene (Ni(OH)2/NG), subsequently, small and uniform nickel oxide nanoparticle (NiO/NG) is also successfully obtained through tube furnace calcination method. The high specific capacitance of the NiO/NG electrode can reach to 1314.1 F/g at a charge and discharge current density of 2 A/g, meanwhile the specific capacitance of Ni(OH)2/NG electrode is also 1350 F/g. The capacitance of NiO/NG can remain 93.7% of the maximum value after 1000 cycles, while the Ni(OH)2/NG electrode losses 16.9% of the initial capacitance after 1000 cycles. It can be attributed to nickel hydroxide instability during charge-discharge cycles.

  17. Structural, optical and electrical characteristics of nickel oxide thin films synthesised through chemical processing method

    Science.gov (United States)

    Akinkuade, Shadrach; Mwankemwa, Benanrd; Nel, Jacqueline; Meyer, Walter

    2018-04-01

    A simple and cheap chemical deposition method was used to produce a nickel oxide (NiO) thin film on glass substrates from a solution that contained Ni2+ and monoethanolamine. Thermal treatment of the film at temperatures above 350 °C for 1 h caused decomposition of the nickel hydroxide into nickel oxide. Structural, optical and electrical properties of the film were studied using X-ray diffraction (XRD), spectrophotometry, current-voltage measurements and scanning electron microscopy (SEM). The film was found to be polycrystalline with interplanar spacing of 0.241 nm, 0.208 nm and 0.148 nm for (111), (200) and (220) planes respectively, the lattice constant a was found to be 0.417 nm. The film had a porous surface morphology, formed from a network of nanowalls of average thickness of 66.67 nm and 52.00 nm for as-deposited and annealed films respectively. Transmittance of visible light by the as-deposited film was higher and the absorption edge of the film blue-shifted after annealing. The optical band gap of the annealed film was 3.8 eV. Electrical resistivity of the film was 378 Ωm.

  18. Essential elucidation for preparation of supported nickel phosphide upon nickel phosphate precursor

    International Nuclear Information System (INIS)

    Liu, Xuguang; Xu, Lei; Zhang, Baoquan

    2014-01-01

    Preparation of supported nickel phosphide (Ni 2 P) depends on nickel phosphate precursor, generally related to its chemical composition and supports. Study of this dependence is essential and meaningful for the preparation of supported Ni 2 P with excellent catalytic activity. The chemical nature of nickel phosphate precursor is revealed by Raman and UV–vis spectra. It is found that initial P/Ni mole ratio ≥0.8 prohibits the Ni-O-Ni bridge bonding (i.e., nickel oxide). This chemical bonding will not result in Ni 2 P structure, verified by XRD characterization results. The alumina (namely, γ-Al 2 O 3 , θ-Al 2 O 3 , or α-Al 2 O 3 ) with distinct physiochemical properties also results in diverse chemical nature of nickel phosphate, and then different nickel phosphides. The influence of alumina support on producing Ni 2 P was explained by the theory of surface energy heterogeneity, calculated by the NLDFT method based on N 2 -sorption isotherm. The uniform surface energy of α-Al 2 O 3 results only in the nickel phosphosate precursor and thus the Ni 2 P phase. - Graphical abstract: Surface energy heterogeneity in alumina (namely α-Al 2 O 3 , θ-Al 2 O 3 , and γ-Al 2 O 3 ) supported multi-oxidic precursors with different reducibilities and thus diverse nickel phosphides (i.e., Ni 3 P, Ni 12 P 5 , Ni 2 P). - Highlights: • Preparing pure Ni 2 P. • Elucidating nickel phosphate precursor. • Associating with surface energy

  19. Effect of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium

    International Nuclear Information System (INIS)

    Pu, Zhen; Chen, Xianglin; Meng, Xiandong; Wu, Yanping; Shen, Liang; Wang, Qingfu; Liu, Tianwei; Shuai, Maobing

    2017-01-01

    Highlights: •The Volta potential differences relative to the matrix are positive for both types of inclusions. •Both types of inclusions are cathodic in the “inclusion/matrix” microgalvanic couples. •The oxide-rich inclusions show a larger Volta potential value of about 115 mV than the carbo-nitride-rich inclusions. •The oxide-rich inclusions give stronger local galvanic coupling with the matrix. •The oxide-rich inclusions are more predisposed to initiate pitting corrosion. -- Abstract: The effects of carbo-nitride-rich and oxide-rich inclusions on the pitting susceptibility of depleted uranium were investigated by electrochemical corrosion measurements, optical microscopy, scanning Kelvin probe force microscopy (SKPFM), and SEM. The results of the potentiodynamic polarization tests suggest that oxide-rich inclusions are more likely to induce pitting corrosion than carbo-nitride-rich inclusions. This enhanced corrosion may be explained by the strong local galvanic coupling between the oxide-rich inclusion and the surrounding matrix, which, from the sight of SKPFM analysis, exhibits a 115 V higher Volta potential than the coupling between the carbo-nitride-rich inclusions and the matrix, respectively.

  20. Hot corrosion studies on nickel-based alloys containing silicon

    International Nuclear Information System (INIS)

    Kerr, T.W.; Simkovich, G.

    1976-01-01

    Alloys of Ni--Cr, Ni--Si and Ni--Cr--Si were oxidized and ''hot corroded'' in pure oxygen at 1000 0 C. In the oxidation experiments it was found that small amounts of either chromium or silicon in nickel increased the oxidation rates in comparison to pure nickel in accord with Wagner's parabolic oxidation theory. At high concentrations of the alloying elements the oxidation rates decreased due to the formation of oxide phases other than nickel oxide in the scale. Hot corrosion experiments were conducted on both binary and ternary alloys by oxidizing samples coated with 1.0 mg/cm 2 of Na 2 SO 4 in oxygen at 1000 0 C. In general it was found that high chromium and high silicon alloys displayed excellent resistance to the hot corrosion process gaining or losing less than 0.5 mg/cm 2 in 1800 min at temperature. Microprobe and x-ray diffraction studies of the alloy and the scale indicate that amorphous SiO 2 probably formed to aid in retarding both the oxidation and the hot corrosion process

  1. Interphase evolution at two promising electrode materials for Li-ion batteries: LiFePO4 and LiNi1/2 Mn1/2O2.

    Science.gov (United States)

    Dupré, Nicolas; Cuisinier, Marine; Martin, Jean-Frederic; Guyomard, Dominique

    2014-07-21

    The present review reports the characterization and control of interfacial processes occurring on olivine LiFePO(4) and layered LiNi(1/2) Mn(1/2)O(2), standing here as model compounds, during storage and electrochemical cycling. The formation and evolution of the interphase created by decomposition of the electrolyte is investigated by using spectroscopic tools such as magic-angle-spinning nuclear magnetic resonance ((7)Li,(19)F and (31)P) and electron energy loss spectroscopy, in parallel to X-ray photoelectron spectroscopy, to quantitatively describe the interphase and unravel its architecture. The influence of the pristine surface chemistry of the active material is carefully examined. The importance of the chemical history of the surface of the electrode material before any electrochemical cycling and the strong correlation between interface phenomena, the formation/evolution of an interphase, and the electrochemical behavior appear clearly from the use of these combined characterization probes. This approach allows identifying interface aging and failure mechanisms. Different types of surface modifications are then investigated, such as intrinsic modifications upon aging in air or methods based on the use of additives in the electrolyte or carbon coatings on the surface of the active materials. In each case, the species detected on the surface of the materials during storage and cycling are correlated with the electrochemical performance of the modified positive electrodes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Decomposition of hydrogen peroxide on nickel oxide - vanadium pentoxide catalysts and the effect of ionizing radiation on them

    International Nuclear Information System (INIS)

    Mucka, V.

    1984-01-01

    Some physico-chemical and catalytic properties of nickel oxide-vanadium pentoxide two-component catalysts were studied over the entire concentration range of the components, using the decomposition of hydrogen peroxide in an aqueous solution as the test reaction. The two oxides were found to affect each other; this was shown by the dependences of the specific surface area, the V 4+ ion concentration, and the catalyst activity on the system composition. At low vanadium pentoxide concentrations (up to 15 mol%) the reaction took place on nickel oxide modified with vanadium pentoxide, whereas in the region of higher vanadium pentoxide concentrations the decomposition of the peroxide was catalyzed primarily in the homogeneous phase by vanadium(V) peroxide ions; in a sample with 30 mol% V 2 O 5 , trivalent vanadium also played a part. With catalysts obtained by mere mechanical mixing of the two oxides, a modified activity was observed in the region of high excess of nickel oxide. The activity of catalyst, particularly pure nickel oxide, was increased by its partial reduction and decreased by its exposure to gamma radiation if the dose was higher than 10 5 Gy. The effects observed are interpreted in terms of the concept of bivalent catalytic centres. (author)

  3. Sequential application of Fenton and ozone-based oxidation process for the abatement of Ni-EDTA containing nickel plating effluents.

    Science.gov (United States)

    Zhao, Zilong; Liu, Zekun; Wang, Hongjie; Dong, Wenyi; Wang, Wei

    2018-07-01

    Treatment of Ni-EDTA in industrial nickel plating effluents was investigated by integrated application of Fenton and ozone-based oxidation processes. Determination of integrated sequence found that Fenton oxidation presented higher apparent kinetic rate constant of Ni-EDTA oxidation and capacity for contamination load than ozone-based oxidation process, the latter, however, was favorable to guarantee the further mineralization of organic substances, especially at a low concentration. Serial-connection mode of two oxidation processes was appraised, Fenton effluent after treated by hydroxide precipitation and filtration negatively affected the overall performance of the sequential system, as evidenced by the removal efficiencies of Ni 2+ and TOC dropping from 99.8% to 98.7%, and from 74.8% to 66.6%, respectively. As a comparison, O 3 /Fe 2+ oxidation process was proved to be more effective than other processes (e.g. O 3 -Fe 2+ , O 3 /H 2 O 2 /Fe 2+ , O 3 /H 2 O 2 -Fe 2+ ), and the final effluent Ni 2+ concentration could satisfied the discharge standard (Fenton reaction, initial influent pH of 3.0, O 3 dosage of 252 mg L -1 , Fe 2+ of 150 mg L -1 , and reaction time of 30 min for O 3 /Fe 2+ oxidation). Furthermore, pilot-scale test was carried out to study the practical treatability towards the real nickel plating effluent, revealing the effective removal of some other co-existence contaminations. And Fenton reaction has contributed most, with the percentage ranging from 72.41% to 93.76%. The economic cost advantage made it a promising alternative to the continuous Fenton oxidation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Facile synthesis of the Li-rich layered oxide Li1.23Ni0.09Co0.12Mn0.56O2 with superior lithium storage performance and new insights into structural transformation of the layered oxide material during charge-discharge cycle: in situ XRD characterization.

    Science.gov (United States)

    Shen, Chong-Heng; Wang, Qin; Fu, Fang; Huang, Ling; Lin, Zhou; Shen, Shou-Yu; Su, Hang; Zheng, Xiao-Mei; Xu, Bin-Bin; Li, Jun-Tao; Sun, Shi-Gang

    2014-04-23

    In this work, the Li-rich oxide Li1.23Ni0.09Co0.12Mn0.56O2 was synthesized through a facile route called aqueous solution-evaporation route that is simple and without waste water. The as-prepared Li1.23Ni0.09Co0.12Mn0.56O2 oxide was confirmed to be a layered LiMO2-Li2MnO3 solid solution through ex situ X-ray diffraction (ex situ XRD) and transmission electron microscopy (TEM). Electrochemical results showed that the Li-rich oxide Li1.23Ni0.09Co0.12Mn0.56O2 material can deliver a discharge capacity of 250.8 mAhg(-1) in the 1st cycle at 0.1 C and capacity retention of 86.0% in 81 cycles. In situ X-ray diffraction technique (in situ XRD) and ex situ TEM were applied to study structural changes of the Li-rich oxide Li1.23Ni0.09Co0.12Mn0.56O2 material during charge-discharge cycles. The study allowed observing experimentally, for the first time, the existence of β-MnO2 phase that is appeared near 4.54 V in the first charge process, and a phase transformation of the β-MnO2 to layered Li0.9MnO2 is occurred in the initial discharge process by evidence of in situ XRD pattrens and selected area electron diffraction (SAED) patterns at different states of the initial charge and discharge process. The results illustrated also that the variation of the in situ X-ray reflections during charge-discharge cycling are clearly related to the changes of lattice parameters of the as-prepared Li-rich oxide during the charge-discharge cycles.

  5. Photoconduction in silicon rich oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Luna-Lopez, J A; Carrillo-Lopez, J; Flores-Gracia, F J; Garcia-Salgado, G [CIDS-ICUAP, Benemerita Universidad Autonoma de Puebla. Ed. 103 D and C, col. San Manuel, Puebla, Pue. Mexico 72570 (Mexico); Aceves-Mijares, M; Morales-Sanchez, A, E-mail: jluna@buap.siu.m, E-mail: jluna@inaoep.m [INAOE, Luis Enrique Erro No. 1, Apdo. 51, Tonantzintla, Puebla, Mexico 72000 (Mexico)

    2009-05-01

    Photoconduction of silicon rich oxide (SRO) thin films were studied by current-voltage (I-V) measurements, where ultraviolet (UV) and white (Vis) light illumination were applied. SRO thin films were deposited by low pressure chemical vapour deposition (LPCVD) technique, using SiH{sub 4} (silane) and N{sub 2}O (nitrous oxide) as reactive gases at 700 {sup 0}. The gas flow ratio, Ro = [N{sub 2}O]/[SiH{sub 4}] was used to control the silicon excess. The thickness and refractive index of the SRO films were 72.0 nm, 75.5 nm, 59.1 nm, 73.4 nm and 1.7, 1.5, 1.46, 1.45, corresponding to R{sub o} = 10, 20, 30 and 50, respectively. These results were obtained by null ellipsometry. Si nanoparticles (Si-nps) and defects within SRO films permit to obtain interesting photoelectric properties as a high photocurrent and photoconduction. These effects strongly depend on the silicon excess, thickness and structure type. Two different structures (Al/SRO/Si and Al/SRO/SRO/Si metal-oxide-semiconductor (MOS)-like structures) were fabricated and used as devices. The photocurrent in these structures is dominated by the generation of carriers due to the incident photon energies ({approx}3.0-1.6 eV and 5 eV). These structures showed large photoconductive response at room temperature. Therefore, these structures have potential applications in optoelectronics devices.

  6. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

  7. The effect of gradient boracic polyanion-doping on structure, morphology, and cycling performance of Ni-rich LiNi0.8Co0.15Al0.05O2 cathode material

    Science.gov (United States)

    Chen, Tao; Li, Xiang; Wang, Hao; Yan, Xinxiu; Wang, Lei; Deng, Bangwei; Ge, Wujie; Qu, Meizhen

    2018-01-01

    A gradient boracic polyanion-doping method is applied to Ni-rich LiNi0.8Co0.15Al0.05O2 (NCA) cathode material in this study to suppress the capacity/potential fade during charge-discharge cycling. Scanning electron microscope (SEM) results show that all samples present spherical morphology and the secondary particle size increases with increasing boron content. X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) results demonstrate that boracic polyanions are successfully introduced into the bulk material and more enriched in the outer layer. XPS analysis further reveals that the valence state of Ni3+ is partly reduced to Ni2+ at the surface due to the incorporation of boracic polyanions. From the electrochemical measurements, B0.015-NCA electrode exhibits excellent cycling performance, even at high potential and elevated temperature. Moreover, the SEM images illustrate the presence of cracks and a thick SEI layer on pristine particles after 100 cycles at high temperature, while the B0.015-NCA particles show an intact structure and thin SEI layer. Electrochemical impedance spectroscopy confirms that the boracic polyanion doping could hinder the impedance increase during cycling at elevated temperature. These results clearly indicate that the gradient boracic polyanion-doping contributes to the remarkable enhancement of structure stability and cycling performance of NCA.

  8. Orbital-Specific observation of O2p and Ni3d electrons in LiNi0.5Mn0.5O2, a cathode material for lithium-ion batteries

    Directory of Open Access Journals (Sweden)

    Yoshinori Satou

    2017-09-01

    Full Text Available Cathode materials for lithium-ion batteries containing Ni2+ have attracted much interest because of their high theoretical capacity. However, the precise electronic structures of these cathode materials have not yet been clearly observed, especially the energy positions of the O2p and Ni3d orbitals and the shape of the density of states. The aim of this study was to investigate the relative energy positions and shape of the density of states of O2p and Ni3d for LiNi0.5Mn0.5O2 experimentally. We cleaved a LiNi0.5Mn0.5O2 pellet in an Ar-filled glove box and performed synchrotron ultraviolet photoelectron spectroscopy for different photon energies, which enabled us to investigate the relative cross-section intensity of O2p and Ni3d. As a result, the valence-band structure was determined. We found that O2p electrons are itinerant and exist in the vicinity of the Fermi energy more than Ni3d electrons. Ni3d electrons are more localized and spread mainly from 1.21.5 eV below the Fermi energy. To validate the electronic structure, we measured the synchrotron O K-edge X-ray absorption fine structure of electrochemically lithium-extracted LiNi0.5Mn0.5O2. The electronic structure demonstrated that ligand holes in the oxygen atoms form below the Fermi level during the initial stage of Li extraction and that the formation rate of the holes decreases with Li extraction.

  9. Effects of lithium-active manganese trioxide coating on the structural and electrochemical characteristics of LiNi_0_._5Co_0_._2Mn_0_._3O_2 as cathode materials for lithium ion battery

    International Nuclear Information System (INIS)

    Li, Lingjun; Yao, Qi; Chen, Zhaoyong; Song, Liubin; Xie, Tian; Zhu, Huali; Duan, Junfei; Zhang, Kaili

    2015-01-01

    Li_2MnO_3-coated LiNi_0_._5Co_0_._2Mn_0_._3O_2 materials are successfully synthesized by sol–gel method. The effects of various pH values and Li_2MnO_3 contents on the structural and electrochemical properties of LiNi_0_._5Co_0_._2Mn_0_._3O_2 cathode materials are systematically investigated, respectively. Scanning electron microscope, transmission electron microscope and energy dispersive spectrometer confirm that the particles of LiNi_0_._5Co_0_._2Mn_0_._3O_2 are completely coated by crystalline Li_2MnO_3 phase. Electrochemical tests show that suitable Li_2MnO_3-coated samples exhibit higher rate capacity and better cycling performance than those of the pristine one. This improvement can be attributed to the synergetic contribution from the neutral pH value and appropriate Li_2MnO_3 amount. The neutral pH environment can protect the core material from damaging during the coating process and is conducive to relieving the rapid moisture uptaking problem of LiNi_0_._5Co_0_._2Mn_0_._3O_2. While, suitable Li_2MnO_3 coating can protect the bulk from directly contacting the electrolyte and offer a fast Li"+ diffusion path at the interface of bulk and electrolyte. - Graphical abstract: The 5% Li_2MnO_3-coated LiNi_0_._5Co_0_._2Mn_0_._3O_2 sample, modified at pH 6, exhibits a conformal and amorphous coating layer before calcination. After been sintered at 880 °C for 5 h, the sample shows Li_2MnO_3 crystalline surface, as well as superior electrochemical performance. - Highlights: • Li_2MnO_3-coated LiNi_0_._5Co_0_._2Mn_0_._3O_2 is prepared by sol–gel method. • Neutral pH environment can protect NMC from damaging during the coating process. • Li_2MnO_3 coating enhances the pristine at high cyclability and rate properties. • Suitable Li_2MnO_3 modification results in better Li"+ diffusion coefficient. • The 5% Li_2MnO_3-coated sample exhibits the best electrochemical performance.

  10. Inverse electron-demand 1,3-dipolar cycloaddition of nitrile oxide with common nitriles leading to 3-functionalized 1,2,4-oxadiazoles.

    Science.gov (United States)

    Nishiwaki, Nagatoshi; Kobiro, Kazuya; Hirao, Shotaro; Sawayama, Jun; Saigo, Kazuhiko; Ise, Yumiko; Okajima, Yoshikazu; Ariga, Masahiro

    2011-10-07

    A carbamoyl-substituted nitrile oxide was generated upon treatment of easily available 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with THF (not dried); the reaction proceeded efficiently even in the absence of any special reagents and reaction conditions. The nitrile oxide caused 1,3-dipolar cycloaddition with common aliphatic nitriles or electron-rich aromatic nitriles to afford 3-functionalized 1,2,4-oxadiazoles, which are expected to serve as precursors for the preparation of a variety of functional materials by the chemical transformation of the carbamoyl group. While conventional preparative methods for 1,2,4-oxadiazoles involve the cycloaddition of an electron-rich nitrile oxide with an electron-deficient nitrile or a nitrile activated by a Lewis acid, our method employs the complementary combination of an electron-rich nitrile and an electron-deficient nitrile oxide- the inverse electron-demand 1,3-cycloaddition. The DFT calculations using B3LYP 6-31G* supported the abovementioned inverse reactivity, and also suggested the presence of an accelerating effect by the carbamoyl group as a result of hydrogen bond formation with a dipolarophilic nitrile.

  11. Carbon deposition and sulfur poisoning during CO2 electrolysis in nickel-based solid oxide cell electrodes

    Science.gov (United States)

    Skafte, Theis Løye; Blennow, Peter; Hjelm, Johan; Graves, Christopher

    2018-01-01

    Reduction of CO2 to CO and O2 in the solid oxide electrolysis cell (SOEC) has the potential to play a crucial role in closing the CO2 loop. Carbon deposition in nickel-based cells is however fatal and must be considered during CO2 electrolysis. Here, the effect of operating parameters is investigated systematically using simple current-potential experiments. Due to variations of local conditions, it is shown that higher current density and lower fuel electrode porosity will cause local carbon formation at the electrochemical reaction sites despite operating with a CO outlet concentration outside the thermodynamic carbon formation region. Attempts at mitigating the issue by coating the composite nickel/yttria-stabilized zirconia electrode with carbon-inhibiting nanoparticles and by sulfur passivation proved unsuccessful. Increasing the fuel electrode porosity is shown to mitigate the problem, but only to a certain extent. This work shows that a typical SOEC stack converting CO2 to CO and O2 is limited to as little as 15-45% conversion due to risk of carbon formation. Furthermore, cells operated in CO2-electrolysis mode are poisoned by reactant gases containing ppb-levels of sulfur, in contrast to ppm-levels for operation in fuel cell mode.

  12. Synthesis and characterization of nickel oxide doped barium strontium titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, M. [Dept. of Electrical Engineering, Bengal Institute of Technology Kolkata (India); Mukherjee, S. [Dept. of Metallurgical Engineering, Jadavpur University, Kolkata (India); Maitra, S. [Govt. College of Engg. and Ceramic Technology, Kolkata (India)

    2012-01-15

    Barium strontium titanate (BST) ceramics (Ba{sub 0.6}Sr{sub 0.4})TiO{sub 3} were synthesized by solid state sintering using barium carbonate, strontium carbonate and rutile as the precursor materials. The samples were doped with nickel oxide in different proportions. Different phases present in the sintered samples were determined from X-ray diffraction investigation and the distribution of different phases in the microstructure was assessed from scanning electron microscopy study. It was observed that the dielectric properties of BST were modified significantly with nickel oxide doping. These ceramics held promise for applications in tuned circuits. (author)

  13. Compositional and structural variabilities of Mg-rich iron oxide spinels from tuffite

    Directory of Open Access Journals (Sweden)

    W. N. Mussel

    1999-12-01

    Full Text Available Maghemite (γFe2O3 from tuffite is exceptionally rich in Mg, relatively to most of those reportedly found in other mafic lithosystems. To investigate in detail the compositional and structural variabilities of this natural magnetic iron oxide, sets of crystals were isolated from samples collected at different positions in a tuffite weathering mantle. These sets of crystal were individually powdered and studied by X-ray diffractometry, Mössbauer spectroscopy, magnetization measurements and chemical analysis. Lattice parameter of the cubic cell (a0 was found to vary from 0.834(1 to 0.8412(1 nm. Lower a0-values are characteristic of maghemite whereas higher ones are related to a magnetite precursor. FeO content ranges up to 17 mass % and spontaneous magnetization ranges from 8 to 32 J T-1 kg-1. Zero-field room temperature Mössbauer spectra are rather complex, indicating that the hyperfine field distributions due to Fe3+ and mixed valence Fe3+/2+ overlap. The structural variabilities of the (Mg, Ti-rich iron oxide spinels is essentially related to the range of chemical composition of its precursor (Mg, Ti-rich magnetite, and probably to the extent to which it has been oxidized during transformation in soil.

  14. Chemical-wet Synthesis and Electrochemistry of LiNi1/3Co1/3Mn1/3O2 Cathode Materials for Li-ion Batteries

    International Nuclear Information System (INIS)

    Hsieh, Chien-Te; Mo, Chung-Yu; Chen, Yu-Fu; Chung, Yi-Jou

    2013-01-01

    LiNi 1/3 Co 1/3 Mn 1/3 O 2 (LNCM) with a well-ordered layered structure, confirmed by X-ray diffraction, was synthesized by the chemical-wet synthesis incorporated with (i) a pulse microwave-assisted heating of LNCM precursors and (ii) a carbon coating technique. The microwave irradiation periods (i.e., 5–20 min) and amount of carbon additive (i.e., glucose content: 0.1–0.75%) served as key factors in modifying as-prepared LNCM powders. The electrochemical performance of as-prepared LNCM cathodes was well characterized by cyclic voltammetry and charge–discharge cycling at 0.1–5C. Both appropriate microwave heating and carbon coating significantly improve discharge capacity, rate capability, and cycling stability of LNCM cathodes. This improved performance can be attributed to the facts that an appropriate microwave heating of LNCM precursors induces low cation mixing of the layered lattices and the carbon coating enables the creation of outer circuit of charge-transfer pathway, preventing cathode corrosion from direct contact to the electrolyte. The C-coated LNCM cathode shows the increased capacity retention from 70.2 to 93.3% after 50 cycles at 1C. On the basis of the experimental results, both the microwave heating and the carbon coating provide a feasible potential way to improve the electrochemical performance of LNCM cathode, benefiting the development of Li-ion batteries

  15. Optical modeling of nickel-base alloys oxidized in pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Clair, A. [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France); Foucault, M.; Calonne, O. [Areva ANP, Centre Technique Departement Corrosion-Chimie, 30 Bd de l' industrie, BP 181, 71205 Le Creusot (France); Finot, E., E-mail: Eric.Finot@u-bourgogne.fr [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Universite de Bourgogne, 9 avenue Alain Savary, BP 47870, 21078 Dijon cedex (France)

    2012-10-01

    The knowledge of the aging process involved in the primary water of pressurized water reactor entails investigating a mixed growth mechanism in the corrosion of nickel-base alloys. A mixed growth induces an anionic inner oxide and a cationic diffusion parallel to a dissolution-precipitation process forms the outer zone. The in situ monitoring of the oxidation kinetics requires the modeling of the oxide layer stratification with the full knowledge of the optical constants related to each component. Here, we report the dielectric constants of the alloys 600 and 690 measured by spectroscopic ellipsometry and fitted to a Drude-Lorentz model. A robust optical stratification model was determined using focused ion beam cross-section of thin foils examined by transmission electron microscopy. Dielectric constants of the inner oxide layer depleted in chromium were assimilated to those of the nickel thin film. The optical constants of both the spinels and extern layer were determined. - Highlights: Black-Right-Pointing-Pointer Spectroscopic ellipsometry of Ni-base alloy oxidation in pressurized water reactor Black-Right-Pointing-Pointer Measurements of the dielectric constants of the alloys Black-Right-Pointing-Pointer Optical simulation of the mixed oxidation process using a three stack model Black-Right-Pointing-Pointer Scattered crystallites cationic outer layer; linear Ni-gradient bottom layer Black-Right-Pointing-Pointer Determination of the refractive index of the spinel and the Cr{sub 2}O{sub 3} layers.

  16. Investigation of effect of Ag(1), Cd(2) and Zn(2) on chemical nickel plating

    International Nuclear Information System (INIS)

    Lunyatskas, A.M.; Tarozajte, R.K.; Gyanutene, I.K.; Lyaukonis, Yu.Yu.

    1978-01-01

    Investigated is the effect of Ag(1), Cd(2) and Zn(2) on chemical nickel plating using hypophosphite aimed to get corresponding alloys from alkali solutions. The H 2 formed volume and potential of coating have been measured while nickel plating. It is possible to have plating of Ni-P-Ag, Ni-P-Zn, Ni-P-Cd, Ni-P-Zn-Cd content coatings in alkali solutions using hypophosphite Ni-P-Zh and Ni-P-Zn-Cd coatings have corrosion resistance and unporousness. Cd and Zn inclusion in Ni-P coating is supposed to have both chemical and electrochemical origin

  17. High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

    Energy Technology Data Exchange (ETDEWEB)

    G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

    2011-12-31

    The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

  18. Effect of transition metal composition on electrochemical performance of nickel-manganese-based lithium-rich layer-structured cathode materials in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Hiroaki, E-mail: hiroaki.konishi.yj@hitachi.com; Gunji, Akira; Feng, Xiaoliang; Furutsuki, Sho

    2017-05-15

    To evaluate the effect of transition metal composition on the electrochemical properties of Li-rich layer-structured cathode materials, Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4) were synthesized, and their electrochemical properties were investigated. As nickel content x increased in Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2, 0.25, 0.3, and 0.4), charge-discharge capacities at a low C-rate (0.05 C) decreased. The results obtained by dQ/dV curves indicate that, as the nickel content increased, the discharge capacity below 3.6 V greatly decreased, but that above 3.6 V increased. As the C-rate of the discharge process increased, the discharge reaction of Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2) below 3.6 V greatly decreased. In contrast, that above 3.6 V slightly decreased. This indicates that the discharge reaction above 3.6 V exhibits higher rate performance than that below 3.6 V. For the high-nickel-content cathodes, the ratio of the discharge capacity above 3.6 V to the total discharge capacity was high. Therefore, they exhibited high rate performance. - Graphical abstract: Figure shows the discharge curves of Li{sub 1.2}Ni{sub x}Mn{sub 0.8−x}O{sub 2} (x=0.2 and 0.3) within potential range of 2.5−4.6 V (vs. Li/Li{sup +}) at 0.05 and 3 C. At low C-rate (0.05 C), the discharge capacity of high-nickel-content cathode (Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2}) was less than that of low-nickel-content cathode (Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2}); however, the discharge potential and capacity of Li{sub 1.2}Ni{sub 0.3}Mn{sub 0.5}O{sub 2} was higher than those of Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.6}O{sub 2} at high C-rate (3 C). This means that the increase in Ni/Mn ratio was effective in improving rate-performance.

  19. High Temperature Corrosion of Nickel in NaVO3-V2O5 Melts

    Directory of Open Access Journals (Sweden)

    J. Porcayo-Calderon

    2017-01-01

    Full Text Available Many alloys used at high temperature in industrial processes are Ni-based and many others contain it in appreciable quantities, so it is of interest to evaluate the performance of pure nickel in order to determine the behavior of its alloys once the elements responsible for their protection have been depleted due to accelerated corrosion processes in the presence of vanadium-rich molten salts. Due to this, this work presents the study of Ni behavior in NaVO3-V2O5 mixtures at different temperatures. The behavior of pure nickel was determined by both electrochemical and mass loss measurements. The results show that the aggressiveness of the vanadium salts is increased by increasing both the V2O5 content and temperature. V2O5 addition considerably increases the current densities of the anodic and cathodic reactions. The corrosion process of Ni is modified due to the presence of its corrosion products, and its presence increases the activation energy by at least one order of magnitude. Although nickel shows a high reactivity in vanadium-rich salts, its reaction products are highly stable and protect it from the corrosive medium because the corrosion reactions trap the vanadium and block the migration of nickel ions.

  20. Recovery Of Nickel From Spent Nickel-Cadmium Batteries Using A Direct Reduction Process

    Directory of Open Access Journals (Sweden)

    Shin D.J.

    2015-06-01

    Full Text Available Most nickel is produced as Ferro-Nickel through a smelting process from Ni-bearing ore. However, these days, there have been some problems in nickel production due to exhaustion and the low-grade of Ni-bearing ore. Moreover, the smelting process results in a large amount of wastewater, slag and environmental risk. Therefore, in this research, spent Ni-Cd batteries were used as a base material instead of Ni-bearing ore for the recovery of Fe-Ni alloy through a direct reduction process. Spent Ni-Cd batteries contain 24wt% Ni, 18.5wt% Cd, 12.1% C and 27.5wt% polymers such as KOH. For pre-treatment, Cd was vaporized at 1024K. In order to evaluate the reduction conditions of nickel oxide and iron oxide, pre-treated spent Ni-Cd batteries were experimented on under various temperatures, gas-atmospheres and crucible materials. By a series of process, alloys containing 75 wt% Ni and 20 wt% Fe were produced. From the results, the reduction mechanism of nickel oxide and iron oxide were investigated.

  1. Shape memory behavior of single and polycrystalline nickel rich nickel titanium alloys

    Science.gov (United States)

    Kaya, Irfan

    NiTi is the most commonly used shape memory alloy (SMA) and has been widely used for bio-medical, electrical and mechanical applications. Nickel rich NiTi shape memory alloys are coming into prominence due to their distinct superelasticity and shape memory properties as compared to near equi-atomic NiTi shape memory alloys. Besides, their lower density and higher work output than steels makes these alloys an excellent candidate for aerospace and automotive industry. Shape memory properties and phase transformation behavior of high Ni-rich Ni54Ti46 (at.%) polycrystals and Ni-rich Ni 51Ti49 (at.%) single-crystals are determined. Their properties are sensitive to heat treatments that affect the phase transformation behavior of these alloys. Phase transformation properties and microstructure were investigated in aged Ni54Ti46 alloys with differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) to reveal the precipitation characteristics and R-phase formation. It was found that Ni54Ti46 has the ability to exhibit perfect superelasticity under high stress levels (~2 GPa) with 4% total strain after 550°C-3h aging. Stress independent R-phase transformation was found to be responsible for the change in shape memory behavior with stress. The shape memory responses of [001], [011] and [111] oriented Ni 51Ti49 single-crystals alloy were reported under compression to reveal the orientation dependence of their shape memory behavior. It has been found that transformation strain, temperatures and hysteresis, Classius-Clapeyron slopes, critical stress for plastic deformation are highly orientation dependent. The effects of precipitation formation and compressive loading at selected temperatures on the two-way shape memory effect (TWSME) properties of a [111]- oriented Ni51Ti49 shape memory alloy were revealed. Additionally, aligned Ni4Ti3 precipitates were formed in a single crystal of Ni51Ti49 alloy by aging under applied compression stress along the

  2. Effect of preparation methods of LiNi1-xCoxO2 cathode materials on their chemical structure and electrode performance

    International Nuclear Information System (INIS)

    Cho, J.; Kim, G.; Lim, H.S.

    1999-01-01

    The authors have studied effects of different starting materials on preparation of LiNi 1-x Co x O 2 cathode material for a Li-ion cell where x = 0.1, 0.2, and 0.3, and the electrochemical properties of resulting compounds from two different preparation methods. A preparation method (method B) which uses spherical powder of Ni 1-x Co x (OH) 2 as one of the starting material produced a much superior cathode material than the other method (method A) which uses Ni(OH) 2 and Co(OH) 2 . Method A produced compounds with relatively high degrees of cation mixing which reduces electrochemical utilization (discharge capacity), increases irreversible capacity, and reduces stability on cycling of the cathode material. Method B, in contrast, produced cathode material with a much reduced degree of cation-mixing, thus improving the electrochemical properties. The spherical particle of material prepared by method B has the additional advantage of improved packing density of the electrode with improved volumetric energy density. The ratio of c/a was increased and the electrochemical stability on cycling of the material was improved as the content of Co (value of x) is increased

  3. Effects of Residual Lithium in the precursors of Li[Ni1/3Co1/3Mn1/3]O2 on their lithium-ion battery performance

    Science.gov (United States)

    Jo, Minsang; Ku, Heesuk; Park, Sanghyuk; Song, Junho; Kwon, Kyungjung

    2018-07-01

    Li[Ni1/3Co1/3Mn1/3]O2 cathode active materials are synthesized from co-precipitated hydroxide precursors Lix[Ni1/3Co1/3Mn1/3]1-x(OH)2, and the effect of residual Li in the precursors on the lithium-ion battery (LIB) performance of their corresponding cathode active materials is investigated. Three kinds of precursors that contain different amounts of Li are selected depending on different conditions of the solution composition for the co-precipitation and washing process. It is confirmed that the introduction of Li to the precursors reduces the degree of structural perfection by X-ray diffraction analysis. Undesirable cation mixing occurs with the increasing Li content of the precursors, which is inferred from a decline in lattice parameters and the calculated intensity ratio of (003) and (104) peaks. In the voltage range of 3.0-4.3 V, the initial charge/discharge capacities and the rate capability of the cathode active materials are aggravated when Li exists in the precursors. Therefore, it could be concluded that the strict control of Li in a solution for co-precipitation of precursors is necessary in the resynthesis of cathode active materials from spent LIBs.

  4. Design and Fabrication of Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged Combustion Thrust Chamber Injectors

    Science.gov (United States)

    Garcia, C. P.; Medina, C. R.; Protz, C. S.; Kenny, R. J.; Kelly, G. W.; Casiano, M. J.; Hulka, J. R.; Richardson, B. R.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. On the current project, several configurations of new main injectors were considered for the thrust chamber assembly of the integrated test article. All the injector elements were of the gas-centered swirl coaxial type, similar to those used on the Russian oxidizer-rich staged-combustion rocket engines. In such elements, oxidizer-rich combustion products from the preburner/turbine exhaust flow through a straight tube, and fuel exiting from the combustion chamber and nozzle regenerative cooling circuits is injected near the exit of the oxidizer tube through tangentially oriented orifices that impart a swirl motion such that the fuel flows along the wall of the oxidizer tube in a thin film. In some elements there is an orifice at the inlet to the oxidizer tube, and in some elements there is a sleeve or "shield" inside the oxidizer tube where the fuel enters. In the current project, several variations of element geometries were created, including element size (i.e., number of elements or pattern density), the distance from the exit of the sleeve to the injector face, the width of the gap between the oxidizer tube inner wall and the outer wall of the sleeve, and excluding the sleeve entirely. This paper discusses the design rationale for each of these element variations, including hydraulic, structural

  5. Microstructural characteristics of high-temperature oxidation in nickel-base superalloy

    International Nuclear Information System (INIS)

    Khalid, F.A.

    1997-01-01

    Superalloys are used for aerospace and nuclear applications where they can withstand high-temperature and severe oxidizing conditions. High-temperature oxidation behavior of a nickel-base superalloy is examined using optical and scanning electron microscopical techniques. The morphology of the oxide layers developed is examined, and EDX microanalysis reveals diffusion of the elements across the oxide-metal interface. Evidence of internal oxidation is presented, and the role of structural defects is considered. The morphology of the oxide-metal interface formed in the specimens exposed in steam and air is examined to elucidate the mechanism of high-temperature oxidation

  6. Prostaglandin E1 and prostaglandin F2 alpha in exudate in nickel allergy

    DEFF Research Database (Denmark)

    Lerche, A; Bisgaard, H; Kassis, V

    1989-01-01

    Ten nickel-allergic patients and 5 healthy control subjects participated in a study of the kinetics of the flux and concentration of migrated leukocytes and extracellular PGE1 and PGF2 alpha during a 48 h period, using a skin chamber technique. The patients were provided with two skin chambers, one...... with and one without nickel challenge. A higher flux of leukocytes, PGE1 and PGF2 alpha was observed during the second day of allergen exposure, while the concentrations probably due to dilution were unchanged or diminished, indicating an unspecific role of the prostaglandins during the contact allergic...

  7. Preliminary results on the chemical characterisation of the cathode nickel--emissive layer interface in oxide cathodes

    International Nuclear Information System (INIS)

    Jenkins, S.N.; Barber, D.K.; Whiting, M.J.; Baker, M.A.

    2003-01-01

    In cathode ray tube (CRT) thermionic oxide cathodes, the nickel-oxide interface properties are key to understanding the mechanisms of operation. At the elevated operational temperatures, free barium is formed at the interface by the reaction of reducing activators, from the nickel alloy, with barium oxide. The free barium diffuses to the outer surface of the oxide providing a low work function electron-emitting surface. However, during cathode life an interface layer grows between the nickel alloy and oxide, comprised of reaction products. The interfacial layer sets limits on the cathode performance and useful operational lifetime by inhibiting the barium reducing reaction. This paper discusses sample preparation procedures for exposure of the interface and the use of several surface and bulk analytical techniques to study interface layer formation. SEM, AES and SIMS data are presented, which provide preliminary insight into the mechanisms operating during the cathode's lifetime. There is evidence that the activator elements in the nickel alloy base, Al and Mg, are able to diffuse to the surface of the oxide during activation and ageing and that these elements are enriched at the interface after accelerated life

  8. Effect of nickel oxide substitution on bioactivity and mechanical ...

    Indian Academy of Sciences (India)

    In the present work, the effect of addition of nickel oxide that annualizes the .... for required dimension using grinding machine, then sam- ples were subjected to ... the hardness testing machine, the size of the sample was. 10 × 10 × 10 mm ...

  9. In situ oxidation state profiling of nickel hexacyanoferrate derivatized electrodes using line-imaging Raman spectroscopy and multivariate calibration

    International Nuclear Information System (INIS)

    Haight, S.M.; Schwartz, D.T.

    1999-01-01

    Metal hexacyanoferrate compounds show promise as electrochemically switchable ion exchange materials for use in the cleanup of radioactive wastes such as those found in storage basins and underground tanks at the Department of Energy's Hanford Nuclear Reservation. Reported is the use of line-imaging Raman spectroscopy for the in situ determination of oxidation state profiles in nickel hexacyanoferrate derivatized electrodes under potential control in an electrochemical cell. Line-imaging Raman spectroscopy is used to collect 256 contiguous Raman spectra every ∼5 microm from thin films (ca. 80 nm) formed by electrochemical derivatization of nickel electrodes. The cyanide stretching region of the Raman spectrum of the film is shown to be sensitive to iron oxidation state and is modeled by both univariate and multivariate correlations. Although both correlations fit the calibration set well, the multivariate (principle component regression or PCR) model's predictions of oxidation state are less sensitive to noise in the spectrum, yielding a much smoother oxidation state profile than the univariate model. Oxidation state profiles with spatial resolution of approximately 5 microm are shown for a nickel hexacyanoferrate derivatized electrode in reduced, intermediate, and oxidized states. In situ oxidation state profiles indicate that the 647.1 nm laser illumination photo-oxidizes the derivatized electrodes. This observation is confirmed using photoelectrochemical methods

  10. Structural, optical and dielectric properties of pure and chromium (Cr) doped nickel oxide nanoparticles

    Science.gov (United States)

    Gupta, Jhalak; Ahmed, Arham S.

    2018-05-01

    The pure and Cr doped nickel oxide (NiO) nanoparticles have been synthesized by cost effective co-precipitation method having nickel nitrate as initial precursor. The synthesized samples were characterized by X-Ray diffraction (XRD), UV-Visible Spectroscopy(UV-Vis) and LCR meter for structural, optical and dielectric properties respectively. The crystallite size of pure nickel oxide nanoparticles characterized by XRD using Debye Scherer's formula was found to be 21.7nm and the same decreases on increasing Cr concentration whereas optical and dielectric properties were analyzed by UV-Vis and LCR meter respectively. The energy band gaps were determined by UV-Vis using Tauc relation.

  11. One-step synthesis and effect of heat-treatment on the structure and electrochemical properties of LiNi0.5Mn1.5O4 cathode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Wen, Jian-Wu; Zhang, Da-Wei; Zang, Yong; Sun, Xin; Cheng, Bin; Ding, Chu-Xiong; Yu, Yan; Chen, Chun-Hua

    2014-01-01

    Highlights: • A one-step sol-gel route with resorcinol-formaldehyde resin is designed to synthesis LiNi 0.5 Mn 1.5 O 4 . • Fd-3 m phase delivers an excellent high rate performance and stable cycling retention. • A double “w”-shape R-V curve is a potential tool to indicate structure transition. - Abstract: Spinel LiNi 0.5 Mn 1.5 O 4 (Fd-3 m) powders are synthesized by a facile one-step sol-gel approach with a resorcinol formaldehyde (RF) resin as a chelating agent. The cross-linked metal-containing RF xerogel particles are sintered at different high temperatures from 750 to 950 °C to produce several micron-sized LiNi 0.5 Mn 1.5 O 4 powders. Electrochemical measurements suggest that the 850 °C-sintered (in air) sample (Fd-3 m phase) performs the best with a discharge capacity of 141 mAh g −1 at 0.1 C and 110 mAh g −1 at 10 C, and capacity-retention of 96.3% after 60 cycles at 0.25 C and 89% after 200 cycles at 1 C. For comparison, the LiNi 0.5 Mn 1.5 O 4 sample sintered at 850 °C in O 2 (P4 3 32 phase) presents limited rate performance (45 mAh g −1 at 10 C) and higher values in both AC impedance and DC-method derived resistance. A characteristic double “w”-shape curve of DC resistance against cell potential can be possibly considered as an indicator to probe the material structure transition during the charge/discharge process of the cell

  12. Crystal structures and catalytic performance of three new methoxy substituted salen type nickel(II) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

    Science.gov (United States)

    Ghaffari, Abolfazl; Behzad, Mahdi; Pooyan, Mahsa; Amiri Rudbari, Hadi; Bruno, Giuseppe

    2014-04-01

    Three new nickel(II) complexes of a series of methoxy substituted salen type Schiff base ligands were synthesized and characterized by IR, UV-Vis and 1H NMR spectroscopy and elemental analysis. The ligands were synthesized from the condensation of meso-1,2-diphenyl-1,2-ethylenediamine with n-methoxysalicylaldehyde (n = 3, 4 and 5). Crystal structures of these complexes were determined. Electrochemical behavior of the complexes was studied by means of cyclic voltammetry in DMSO solutions. Catalytic performance of the complexes was studied in the epoxidation of cyclooctene using tert-butylhydroperoxide (TBHP) as oxidant under various conditions to find the optimum operating parameters. Low catalytic activity with moderate epoxide selectivity was observed in in-solvent conditions but in the solvent-free conditions, enhanced catalytic activity with high epoxide selectivity was achieved.

  13. Solubility of nickel ferrite (NiFe2O4) from 100 to 200 deg. C

    International Nuclear Information System (INIS)

    Bellefleur, Alexandre; Bachet, Martin; Benezeth, Pascale; Schott, Jacques

    2012-09-01

    The solubility of nickel ferrite was measured in a Hydrogen-Electrode Concentration Cell (HECC) at temperatures of 100 deg. C, 150 deg. C and 200 deg. C and pH between 4 and 5.25. The experimental solution was composed of HCl and NaCl (0.1 mol.L -1 ). Based on other studies ([1,2]), pure nickel ferrite was experimentally synthesized by calcination of a mixture of hematite Fe 2 O 3 and bunsenite NiO in molten salts at 1000 deg. C for 15 hours in air. The so obtained powder was fully characterized. The Hydrogen-Electrode Concentration cell has been described in [3]. It allowed us to run solubility experiments up to 250 deg. C with an in-situ pH measurement. To avoid reduction of the solid phase to metallic nickel, a hydrogen/argon mixture was used instead of pure hydrogen. Consequently, the equilibration time for the electrodes was longer than with pure hydrogen. Eight samples were taken on a 70 days period. After the experiments, the powder showed no significant XRD evidence of Ni (II) reduction. Nickel concentration was measured by atomic absorption spectroscopy and iron concentration was measured by UV spectroscopy. The protocol has been designed to be able to measure both dissolved Fe (II) and total iron. The nickel solubility of nickel ferrite was slightly lower than the solubility of nickel oxide in close experimental conditions [3]. Dissolved iron was mainly ferrous and the solution was under-saturated relative to both hematite and magnetite. The nickel/iron ratio indicated a non-stoichiometric dissolution. The solubility measurements were compared with equilibrium calculations using the MULTEQ database. [1] Hayashi et al (1980) J. Materials Sci. 15, 1491-1497. [2] Ziemniak et al (2007) J. Physics and Chem. of Solids. 68,10-21. [3] EPRI Report 1003155 (2002). (authors)

  14. The study of chlorination of nickel oxide by chlorine and calcium chloride in the presence of active additives

    OpenAIRE

    Ilic, Ilija; Krstev, Boris; Stopic, Srecko; Cerovic, K

    1997-01-01

    Chlorination of nickel oxide by chlorine and calcium chloride in the presence of C, BaS and S were studied, both experimentally and theoretically. Chlorination of nickel oxide by chlorine was carried out in the temperature range 573-873 K and by calcium chloride in the temperature range 1023-1223 K. The results obtained of the chlorination of nickel oxide by chlorine showed that C has the strongest and S the weakest effect on the process. Addition of BaS has a favorable effect on the chlorina...

  15. Electrochemical reaction mechanisms under various charge-discharge operating conditions for Li1.2Ni0.13Mn0.54Co0.13O2 in a lithium-ion battery

    Science.gov (United States)

    Konishi, Hiroaki; Hirano, Tatsumi; Takamatsu, Daiko; Gunji, Akira; Feng, Xiaoliang; Furutsuki, Sho; Okumura, Takefumi; Terada, Shohei; Tamura, Kazuhisa

    2018-06-01

    The potential in each state of charge (SOC) during charging of Li1.2Ni0.13Mn0.54Co0.13O2 is higher than that during discharging. In other words, the potential hysteresis occurs between charging and discharging. Furthermore, the potential in each SOC changes according to the charge-discharge operating conditions, indicating that the charge-discharge reaction mechanism is also affected. To clarify the effect of charge-discharge operating conditions on the electrochemical reaction, Li1.2Ni0.13Mn0.54Co0.13O2 was charged and discharged under various charge-discharge operating ranges, and open-circuit potential (OCP), crystal structure, and oxidation states of the transition metals were evaluated by electrochemical measurement, X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS). These results indicate that OCP, lattice parameters, and oxidation states of the transition metals of Li1.2Ni0.13Mn0.54Co0.13O2 in each SOC are not constant. The XRD results indicate that two phases, namely, LiNi0.33Mn0.33Co0.33O2-like and Li2MnO3-like, exist in Li1.2Ni0.13Mn0.54Co0.13O2. For the LiNi0.33Mn0.33Co0.33O2-like phase, the relationship between OCP, lattice parameters, and oxidation states of the transition metals in each SOC is not affected by the charge-discharge operating conditions, indicating that extraction and insertion of lithium ions for the LiNi0.33Mn0.33Co0.33O2-like phase progresses at almost the same potential. Although the extraction and insertion of lithium ions for the Li2MnO3-like phase progresses at almost the same potential in the low-SOC region, the OCP and lattice parameter in each SOC in the high-SOC region are not constant. Therefore, the extraction of lithium ions from the Li2MnO3-like phase in the high-SOC region causes the potential hysteresis of Li1.2Ni0.13Mn0.54Co0.13O2.

  16. Iron-Induced Activation of Ordered Mesoporous Nickel Cobalt Oxide Electrocatalyst for the Oxygen Evolution Reaction.

    Science.gov (United States)

    Deng, Xiaohui; Öztürk, Secil; Weidenthaler, Claudia; Tüysüz, Harun

    2017-06-28

    Herein, ordered mesoporous nickel cobalt oxides prepared by the nanocasting route are reported as highly active oxygen evolution reaction (OER) catalysts. By using the ordered mesoporous structure as a model system and afterward elevating the optimal catalysts composition, it is shown that, with a simple electrochemical activation step, the performance of nickel cobalt oxide can be significantly enhanced. The electrochemical impedance spectroscopy results indicated that charge transfer resistance increases for Co 3 O 4 spinel after an activation process, while this value drops for NiO and especially for CoNi mixed oxide significantly, which confirms the improvement of oxygen evolution kinetics. The catalyst with the optimal composition (Co/Ni 4/1) reaches a current density of 10 mA/cm 2 with an overpotential of a mere 336 mV and a Tafel slope of 36 mV/dec, outperforming benchmarked and other reported Ni/Co-based OER electrocatalysts. The catalyst also demonstrates outstanding durability for 14 h and maintained the ordered mesoporous structure. The cyclic voltammograms along with the electrochemical measurements in Fe-free KOH electrolyte suggest that the activity boost is attributed to the generation of surface Ni(OH) 2 species that incorporate Fe impurities from the electrolyte. The incorporation of Fe into the structure is also confirmed by inductively coupled plasma optical emission spectrometry.

  17. Hydrogenation of Levulinic Acid over Nickel Catalysts Supported on Aluminum Oxide to Prepare γ-Valerolactone

    Directory of Open Access Journals (Sweden)

    Jie Fu

    2015-12-01

    Full Text Available Four types of nickel catalysts supported on aluminum oxide (Ni/Al2O3 with different nickel loadings were synthesized using the co-precipitation method and were used for the hydrogenation of levulinic acid (LA to prepare γ-valerolactone (GVL. The synthesized Ni/Al2O3 catalysts exhibited excellent catalytic activity in dioxane, and the activity of the catalysts was excellent even after being used four times in dioxane. The catalytic activity in dioxane as a solvent was found to be superior to the activity in water. Nitrogen physisorption, X-ray diffraction, and transmission electron microscopy were employed to characterize the fresh and used catalysts. The effects of the nickel loading, temperature, hydrogen pressure, and substrate/catalyst ratio on the catalytic activity were investigated.

  18. Absolute determination by X-ray diffraction of a binary or ternary mixture: nickel oxide and fluoride in a nickel powder (1960)

    International Nuclear Information System (INIS)

    Charpin, P.; Hauptman, A.

    1960-01-01

    The method employed is based upon the comparison between computed and measured intensities for conveniently selected X-Ray diffraction lines of each component of the powder. Care must be taken to allow for absorption, both inside each grain and in overall sample. This method has been applied to the determination of nickel oxide and fluoride in a nickel powder. (author) [fr

  19. Microstructure and magnetooptics of silicon oxide with implanted nickel nanoparticles

    International Nuclear Information System (INIS)

    Edel’man, I. S.; Petrov, D. A.; Ivantsov, R. D.; Zharkov, S. M.; Khaibullin, R. I.; Valeev, V. F.; Nuzhdin, V. I.; Stepanov, A. L.

    2011-01-01

    Metallic nickel nanoparticles of various sizes are formed in a thin near-surface layer in an amorphous SiO 2 matrix during 40-keV Ni + ion implantation at a dose of (0.25−1.0) × 10 17 ions/cm 2 . The micro-structure of the irradiated layer and the crystal structure, morphology, and sizes of nickel particles formed at various irradiation doses are studied by transmission electron microscopy and electron diffraction. The magnetooptical Faraday effect and the magnetic circular dichroism in an ensemble of nickel nanoparticles are studied in the optical range. The permittivity ε tensor components are calculated for the implanted samples using an effective medium model with allowance for the results of magnetooptical measurements. The spectral dependences of the tensor ε components are found to be strongly different from those of a continuous metallic nickel film. These differences are related to a disperse structure of the magnetic nickel phase and to a surface plasma resonance in the metal nanoparticles.

  20. Cyclic Oxidation and Hot Corrosion Behavior of Nickel-Iron-Based Superalloy

    Science.gov (United States)

    Chellaganesh, D.; Adam Khan, M.; Winowlin Jappes, J. T.; Sathiyanarayanan, S.

    2018-01-01

    The high temperature oxidation and hot corrosion behavior of nickel-iron-based superalloy are studied at 900 ° and 1000 °C. The significant role of alloying elements with respect to the exposed medium is studied in detail. The mass change per unit area was catastrophic for the samples exposed at 1000 °C and gradual increase in mass change was observed at 900 °C for both the environments. The exposed samples were further investigated with SEM, EDS and XRD analysis to study the metallurgical characteristics. The surface morphology has expressed the in situ nature of the alloy and its affinity toward the environment. The EDS and XRD analysis has evidently proved the presence of protective oxides formation on prolonged exposure at elevated temperature. The predominant oxide formed during the exposure at high temperature has a major contribution toward the protection of the samples. The nickel-iron-based superalloy is less prone to oxidation and hot corrosion when compared to the existing alloy in gas turbine engine simulating marine environment.

  1. Reduced Graphene Oxide on Nickel Foam for Supercapacitor Electrodes

    Directory of Open Access Journals (Sweden)

    Uma Ramabadran

    2017-11-01

    Full Text Available The focus of this paper is the investigation of reduced graphene oxide (GO/nickel foam (RGON samples for use as supercapacitor electrodes. Nickel foam samples were soaked in a GO suspension and dried before being subjected to two different methods to remove oxygen. Atmospheric pressure annealed (APA samples were treated with a varying number (10–18 of nitrogen plasma jet scans, where sample temperatures did not exceed 280 °C. Furnace annealed (FA samples were processed in an atmosphere of hydrogen and argon, at temperatures ranging from 600 °C to 900 °C. Environmental Scanning Electron Microscope (ESEM data indicated that the carbon to oxygen (C:O ratio for APA samples was minimized at an intermediate number of plasma scans. Fourier Transform Infrared Spectroscopic (FTIR and Raman spectroscopic data supported this finding. ESEM analysis from FA samples showed that with increasing temperatures of annealing, GO is transformed to reduced graphene oxide (RGO, with C:O ratios exceeding 35:1. X-ray Photoelectron Spectroscopy (XPS and X-ray diffraction (XRD data indicated the formation of RGO with an increasing annealing temperature until 800 °C, when oxygen reincorporation in the surface atomic layers becomes an issue. Supercapacitors, constructed using the FA samples, demonstrated performances that correlated with surface atomic layer optimization of the C:O ratio.

  2. In situ Reduction and Oxidation of Nickel from Solid Oxide Fuel Cells in a Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Faes, Antonin; Jeangros, Quentin; Wagner, Jakob Birkedal

    2009-01-01

    Environmental transmission electron microscopy was used to characterize in situ the reduction and oxidation of nickel from a Ni/YSZ solid oxide fuel cell anode support between 300-500{degree sign}C. The reduction is done under low hydrogen pressure. The reduction initiates at the NiO/YSZ interface...

  3. Sub-acute nickel exposure impairs behavior, alters neuronal microarchitecture, and induces oxidative stress in rats' brain.

    Science.gov (United States)

    Ijomone, Omamuyovwi Meashack; Okori, Stephen Odey; Ijomone, Olayemi Kafilat; Ebokaiwe, Azubike Peter

    2018-02-26

    Nickel (Ni) is a heavy metal with wide industrial uses. Environmental and occupational exposures to Ni are potential risk factors for neurological symptoms in humans. The present study investigated the behavior and histomorphological alterations in brain of rats sub-acutely exposed to nickel chloride (NiCl 2 ) and the possible involvement of oxidative stress. Rats were administered with 5, 10 or 20 mg/kg NiCl 2 via intraperitoneal injections for 21 days. Neurobehavioral assessment was performed using the Y-maze and open field test (OFT). Histomorphological analyses of brain tissues, as well as biochemical determination of oxidative stress levels were performed. Results showed that Ni treatments significantly reduced body weight and food intake. Cognitive and motor behaviors on the Y-maze and OFT, respectively, were compromised following Ni treatments. Administration of Ni affected neuronal morphology in the brain and significantly reduced percentage of intact neurons in both hippocampus and striatum. Additionally, markers of oxidative stress levels and nitric oxide (NO) levels were significantly altered following Ni treatments. These data suggest that compromised behavior and brain histomorphology following Ni exposures is associated with increase in oxidative stress.

  4. The effects of a nickel oxide precoat on the gas bubble structures and fish-scaling resistance in vitreous enamels

    International Nuclear Information System (INIS)

    Yang, X.; Jha, A.; Brydson, R.; Cochrane, R.C.

    2004-01-01

    The effects of a NiO precoat on the interfacial microchemistry and the structure of gas bubbles at the steel-enamel interface were investigated using scanning electron microscopy (SEM), electron probe microanalysis (EPMA), thermogravimetric analysis (TGA) and image analysis techniques. The experimental evidence demonstrates that nickel oxide applied to the steel substrate as a precoat accelerates the diffusion of Fe from the steel into the enamel and promotes decarburisation of the steel substrate, this latter reaction generating CO and/or CO 2 as gases. The resulting increase in FeO concentration reduces the viscosity of enamel. The apparent decrease in the viscosity of liquid enamel, along with formation of substantial quantities of CO and/or CO 2 gases control the distribution of gas bubbles in the enamel layer. The investigation also explains the reason for the association of large gas bubbles with Fe-Ni metal-rich particles with a dendritic appearance (termed 'dendrites in the following text) at the enamel-steel interface. The role of these Fe-Ni metal-rich 'dendrites' in reducing the tendency for hydrogen flaking or cracking of the enamel layer, generally referred to as fish-scaling, is also elucidated

  5. Engineered Nickel Oxide Nanoparticle Causes Substantial Physicochemical Perturbation in Plants

    Directory of Open Access Journals (Sweden)

    Indrani Manna

    2017-11-01

    Full Text Available Concentration of engineered nickel oxide nanoparticle (NiO-NP in nature is on the rise, owing to large scale industrial uses, which have accreted the scope of its exposure to plants, the primary producers of the ecosystem. Though an essential micronutrient for the animal system, supported by numerous studies confirming its toxicity at higher dosages, nickel oxide is graded as a human carcinogen by WHO. A few studies do depict toxicity and bioaccumulation of nickel in plants; however, interaction of NiO-NP with plants is not well-elucidated. It is known that exposure to NiO-NP can incite stress response, leading to cytotoxicity and growth retardation in some plants, but a defined work on the intricate physicochemical cellular responses and genotoxic challenges is wanting. The present study was planned to explore cytotoxicity of NiO-NP in the model plant, Allium cepa L., its internalization in the tissue and concomitant furore created in the antioxidant enzyme system of the plant. The prospect of the NiO-NP causing genotoxicity was also investigated. Detailed assessments biochemical profiles and genotoxicity potential of NiO-NP on A. cepa L. was performed and extended to four of its closest economically important relatives, Allium sativum L., Allium schoenoprasum L., Allium porrum L., and Allium fistulosum L. Growing root tips were treated with seven different concentrations of NiO-NP suspension (10–500 mg L−1, with deionised distilled water as negative control and 0.4 mM EMS solution as positive control. Study of genotoxic endpoints, like, mitotic indices (MI, chromosomal aberrations (CAs, and chromosome breaks confirmed NiO-NP induced genotoxicity in plants, even at a very low dose (10 mg L−1. That NiO-NP also perturbs biochemical homeostasis, disrupting normal physiology of the cell, was confirmed through changes in state of lipid peroxidation malonaldehyde (MDA, as well as, in oxidation marker enzymes, like catalase (CAT, super oxide

  6. Nickel evaporation in high vacuum and formation of nickel oxide nanoparticles on highly oriented pyrolytic graphite. X-ray photoelectron spectroscopy and atomic force microscopy study

    Czech Academy of Sciences Publication Activity Database

    Franc, Jiří; Bastl, Zdeněk

    2008-01-01

    Roč. 516, č. 18 (2008), s. 6095-6103 ISSN 0040-6090 R&D Projects: GA AV ČR 1ET400400413 Institutional research plan: CEZ:AV0Z40400503 Keywords : nickel oxide nanoparticles * vapour deposition * XPS * AFM Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.884, year: 2008

  7. Synthesis of hierarchical mesoporous lithium nickel cobalt manganese oxide spheres with high rate capability for lithium-ion batteries

    Science.gov (United States)

    Tong, Wei; Huang, Yudai; Cai, Yanjun; Guo, Yong; Wang, Xingchao; Jia, Dianzeng; Sun, Zhipeng; Pang, Weikong; Guo, Zaiping; Zong, Jun

    2018-01-01

    Hierarchical mesoporous LiNi1/3Co1/3Mn1/3O2 spheres have been synthesized by urea-assisted solvothermal method with adding Triton X-100. The structure and morphology of the as-prepared materials were analyzed by X-ray diffraction and electron microscope. The results show that the as-prepared samples can be indexed as hexagonal layered structure with hierarchical architecture, and the possible formation mechanism is speculated. When evaluated as cathode material, the hierarchical mesoporous LiNi1/3Co1/3Mn1/3O2 spheres show good electrochemical properties with high initial discharge capacity of 129.9 mAh g-1, and remain the discharge capacity of 95.5 mAh g-1 after 160 cycles at 10C. The excellent electrochemical performance of the as-prepared sample can be attributed to its stable hierarchical mesoporous framework in conjunction with large specific surface, low cation mixing and small particle size. They not only provide a large number of reaction sites for surface or interface reaction, but also shorten the diffusion length of Li+ ions. Meanwhile, the mesoporous spheres composed of nanoparticles can contribute to high rate ability and buffer volume changes during charge/discharge process.

  8. Understanding CO-stripping mechanism from Ni{sub UPD}/Pt(1 1 0) in view of the measured nickel formal partial charge number upon underpotential deposition on platinum surfaces in sulphate media

    Energy Technology Data Exchange (ETDEWEB)

    Chatenet, Marian [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS-INPG-UJF, BP 75, 38402 Saint-Martin d' Heres Cedex (France)], E-mail: Marian.Chatenet@lepmi.inpg.fr; Soldo-Olivier, Yvonne; Chainet, Eric; Faure, Rene [Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS-INPG-UJF, BP 75, 38402 Saint-Martin d' Heres Cedex (France)

    2007-12-01

    {sub Ni} = 2. In consequence, upon underpotential deposition on platinum surfaces, nickel cations discharge and then undergo additional charge exchange processes, such as anion (or water) adsorption, resulting in apparent partial nickel cation discharge. Moreover, Ni{sub UPD}/Pt(1 1 0) surface displays high activity towards CO{sub ad} oxidation reaction. We explain such positive effect by the possible existence of a bifunctional mechanism in which oxygenated-species-covered Ni{sub UPD} adatoms provide the oxygen atom to CO{sub ad}...Pt species, enabling its facile oxidation.

  9. FTIR study of the influence of minor alloying elements on the high temperature oxidation of nickel alloys

    International Nuclear Information System (INIS)

    Lenglet, M.; Delaunay, F.; Lefez, B.

    1997-01-01

    The purpose of this paper is to study the reflectance spectra of the different single oxide layer systems : Cr 2 O 3 /Fe, MnCr 2 O 4 /Fe, TiO 2 /Fe, NiCr 2 O 4 /Fe and NiFe 2 O 4 /Fe and to extend the theoretical calculations to multilayer oxide systems on metallic substrates. The interpretation of the resulting reflectance spectra for these systems is used to explain the initial stages of oxide formation and the influence of minor alloying elements on the high temperature oxidation of three commercial nickel alloys : Incoloy 800, Inconel 600 and X. (orig.)

  10. Determination of the mechanism and extent of surface degradation in Ni-based cathode materials after repeated electrochemical cycling

    Directory of Open Access Journals (Sweden)

    Sooyeon Hwang

    2016-09-01

    Full Text Available We take advantage of scanning transmission electron microscopy and electron energy loss spectroscopy to investigate the changes in near-surface electronic structure and quantify the degree of local degradation of Ni-based cathode materials with the layered structure (LiNi0.8Mn0.1Co0.1O2 and LiNi0.4Mn0.3Co0.3O2 after 20 cycles of delithiation and lithiation. Reduction of transition metals occurs in the near-surface region of cathode materials: Mn is the major element to be reduced in the case of relatively Mn-rich composition, while reduction of Ni ions is dominant in Ni-rich materials. The valences of Ni and Mn ions are complementary, i.e., when one is reduced, the other is oxidized in order to maintain charge neutrality. The depth of degradation zone is found to be much deeper in Ni-rich materials. This comparative analysis provides important insights needed for the devising of new cathode materials with high capacity as well as long lifetime.

  11. Atomically Monodisperse Nickel Nanoclusters as Highly Active Electrocatalysts for Water Oxidation

    KAUST Repository

    Joya, Khurram

    2016-04-08

    Achieving water splitting at low overpotential with high oxygen evolution efficiency and stability is important for realizing solar to chemical energy conversion devices. Herein we report the synthesis, characterization and electrochemical evaluation of highly active nickel nanoclusters (Ni NCs) for water oxidation at low overpotential. These atomically precise and monodisperse Ni NCs are characterized by using UV-visible absorption spectroscopy, single crystal X-ray diffraction and mass spectrometry. The molecular formulae of these Ni NCs are found to be Ni4(PET)8 and Ni6(PET)12 and are highly active electrocatalysts for oxygen evolution without any pre-conditioning. Ni4(PET)8 are slightly better catalysts than Ni6(PET)12 and initiate the oxygen evolution at an amazingly low overpotential of ~1.51 V (vs RHE; η ≈ 280 mV). The peak oxygen evolution current density (J) of ~150 mA cm–2 at 2.0 V (vs. RHE) with a Tafel slope of 38 mV dec–1 is observed using Ni4(PET)8. These results are comparable to the state-of-the art RuO2 electrocatalyst, which is highly expensive and rare compared to Ni-based materials. Sustained oxygen generation for several hours with an applied current density of 20 mA cm–2 demonstrates the long-term stability and activity of these Ni NCs towards electrocatalytic water oxidation. This unique approach provides a facile method to prepare cost-effective, nanoscale and highly efficient electrocatalysts for water oxidation.

  12. Synthesis of nickel oxide - zirconia composites by coprecipitation route followed by hydrothermal treatment

    International Nuclear Information System (INIS)

    Yoshito, Walter Kenji; Ussui, Valter; Lazar, Dolores Ribeiro Ricci; Paschoal, Jose Octavio Armani

    2009-01-01

    Nickel oxide-yttria stabilized zirconia (NiO-YSZ) for use as solid oxide fuel cell anode were synthesized by coprecipitation to obtain amorphous zirconia and crystallized β-nickel gels of the corresponding metal hydroxides. Hydrothermal treatment at 200°C and 220 psi from 2 up to 16 hours, under stirring, was performed to produce nanocrystalline powder. The as-synthesized powders were uniaxially pressed and sintered in air. Powders were characterized by X-ray diffraction, laser scattering, scanning and transmission electron microscopy (SEM/TEM), gas adsorption technique (BET) and TGDTA thermal analysis. Ceramic samples were characterized by dilatometric analysis and density measurements by Archimedes method. The characteristics of hydrothermally synthesized powders and compacts were compared to those produced without temperature and pressure application. Crystalline powders were obtained after hydrothermal process, excluding the calcination step from this route. The specific surface area of powders decreases with increasing time of hydrothermal treatment while the agglomerate mean size is not affected by this parameter. (author)

  13. Nickel Nanowire@Porous NiCo2O4 Nanorods Arrays Grown on Nickel Foam as Efficient Pseudocapacitor Electrode

    Directory of Open Access Journals (Sweden)

    Houzhao Wan

    2017-12-01

    Full Text Available A three dimensional hierarchical nanostructure composed of nickel nanowires and porous NiCo2O4 nanorods arrays on the surface of nickel foam is successfully fabricated by a facile route. In this structure, the nickel nanowires are used as core materials to support high-pseudocapacitance NiCo2O4 nanorods and construct the well-defined NiCo2O4 nanorods shell/nickel nanowires core hierarchical structure on nickel foam. Benefiting from the participation of nickel nanowires, the nickel nanowire@NiCo2O4/Ni foam electrode shows a high areal specific capacitance (7.4 F cm−2 at 5 mA cm−2, excellent rate capability (88.04% retained at 100 mA cm−2, and good cycling stability (74.08% retained after 1,500 cycles. The superior electrochemical properties made it promising as electrode for supercapacitors.

  14. A Review on Preferential Oxidation of Carbon Monoxide in Hydrogen Rich Gases

    Directory of Open Access Journals (Sweden)

    A. Mishra

    2011-05-01

    Full Text Available In this review, recent works on the preferential oxidation of carbon monoxide in hydrogen rich gases for fuel cell applications are summarized. H2 is used as a fuel for polymer-electrolyte membrane fuel cell (PEMFC. It is produced by reforming of natural gas or liquid fuels followed by water gas shift reaction. The produced gas consists of H2, CO, and CO2. In which CO content is around 1%, which is highly poisonous for the Pt anode of the PEMFC so that further removal of CO is needed. Catalytic preferential oxidation of CO (CO-PROX is one of the most suitable methods of purification of H2 because of high CO conversion rate at low temperature range, which is preferable for PEMFC operating conditions. Catalysts used for COPROX are mainly noble metal based; gold based and base metal oxide catalysts among them Copper-Ceria based catalysts are the most appropriate due to its low cost, easy availability and result obtained by these catalysts are comparable with the conventional noble metal catalysts. Copyright © 2011 BCREC UNDIP. All rights reserved(Received: 22nd October 2010, Revised: 12nd January 2011, Accepted: 19th January 2011[How to Cite: A. Mishra, R. Prasad. (2011. A Review on Preferential Oxidation of Carbon Monoxide in Hydrogen Rich Gases. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (1: 1-14. doi:10.9767/bcrec.6.1.191.1-14][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.191.1-14 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/191] | View in 

  15. Systematic study of nickel oxide ceramic pigment using Ni C O{sub 3}.2 Ni(O H){sub 2}.4 H{sub 2} O as precursor; Estudo sistematico de pigmento ceramico de oxido de niquel usando como precursor o Ni C O{sub 3}.2 Ni(O H){sub 2}.4 H{sub 2} O

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Emilio [Centro Federal de Educacao Tecnologica do Maranhao, MA (Brazil). Dept. de Quimica; Longo, Elson [Sao Carlos Univ., SP (Brazil). Dept. de Quimica

    1997-12-31

    The ability of some ceramics silicate and oxides have to accommodate impurity in the crystal lattice to a large colors diversity. These impurities can be both interstitial or substitutional creating crystal fields in accordance with ion-impurity valence. The technical procedures used to characterize the pigments were: DRX, IV, MEV, and BET. To optimize this property systematic studies were done for nickel oxide with a composition of 0,3% to 30%. In this work it was studied nickel oxide synthesis based on feldspar using Pechini chemistry synthesis. To obtain this powder. (author) 3 refs., 3 figs., 1 tab.

  16. Chemical changes in carbon Nanotube-Nickel/Nickel Oxide Core/Shell nanoparticle heterostructures treated at high temperatures

    International Nuclear Information System (INIS)

    Chopra, Nitin; McWhinney, Hylton G.; Shi Wenwu

    2011-01-01

    Heterostructures composed of carbon nanotube (CNT) coated with Ni/NiO core/shell nanoparticles (denoted as CNC heterostructures) were synthesized in a wet-chemistry and single-step synthesis route involving direct nucleation of nanoparticles on CNT surface. Two different aspects of CNC heterostructures were studied here. First, it was observed that the nanoparticle coatings were more uniform on the as-produced and non-purified CNTs compared to purified (or acid treated) CNTs. These heterostructures were characterized using electron microscopy, Raman spectroscopy, and energy dispersive spectroscopy. Second, thermal stability of CNC heterostructures was studied by annealing them in N 2 -rich (O 2 -lean) environment between 125 and 750 deg. C for 1 h. A detailed X-ray photoelectron spectroscopy and Raman spectroscopy analysis was performed to evaluate the effects of annealing temperatures on chemical composition, phases, and stability of the heterostructures. It was observed that the CNTs present in the heterostructures completely decomposed and core Ni nanoparticle oxidized significantly between 600 and 750 deg. C. - Research Highlights: → Heterostructures composed of CNTs coated with Ni/NiO core/shell nanoparticles. → Poor nanoparticle coverage on purified CNT surface compared to non-purified CNTs. → CNTs in heterostructures decompose between 600 and 750 deg. C in N 2 -rich atmosphere. → Metallic species in heterostructures were oxidized at higher temperatures.

  17. Rare-earth nickelates RNiO3: thin films and heterostructures

    Science.gov (United States)

    Catalano, S.; Gibert, M.; Fowlie, J.; Íñiguez, J.; Triscone, J.-M.; Kreisel, J.

    2018-04-01

    This review stands in the larger framework of functional materials by focussing on heterostructures of rare-earth nickelates, described by the chemical formula RNiO3 where R is a trivalent rare-earth R  =  La, Pr, Nd, Sm, …, Lu. Nickelates are characterized by a rich phase diagram of structural and physical properties and serve as a benchmark for the physics of phase transitions in correlated oxides where electron–lattice coupling plays a key role. Much of the recent interest in nickelates concerns heterostructures, that is single layers of thin film, multilayers or superlattices, with the general objective of modulating their physical properties through strain control, confinement or interface effects. We will discuss the extensive studies on nickelate heterostructures as well as outline different approaches to tuning and controlling their physical properties and, finally, review application concepts for future devices.

  18. Experimental Study and Mathematical Modeling of Self-Sustained Kinetic Oscillations in Catalytic Oxidation of Methane over Nickel.

    Science.gov (United States)

    Lashina, Elena A; Kaichev, Vasily V; Saraev, Andrey A; Vinokurov, Zakhar S; Chumakova, Nataliya A; Chumakov, Gennadii A; Bukhtiyarov, Valerii I

    2017-09-21

    The self-sustained kinetic oscillations in the oxidation of CH 4 over Ni foil have been studied at atmospheric pressure using an X-ray diffraction technique and mass spectrometry. It has been shown that the regular oscillations appear under oxygen-deficient conditions; CO, CO 2 , H 2 , and H 2 O are detected as the products. According to in situ X-ray diffraction measurements, nickel periodically oxidizes to NiO initiating the reaction-rate oscillations. To describe the oscillations, we have proposed a five-stage mechanism of the partial oxidation of methane over Ni and a corresponding three-variable kinetic model. The mechanism considers catalytic methane decomposition, dissociative adsorption of oxygen, transformation of chemisorbed oxygen to surface nickel oxide, and reaction of adsorbed carbon and oxygen species to form CO. Analysis of the kinetic model indicates that the competition of two processes, i.e., the oxidation and the carbonization of the catalyst surface, is the driving force of the self-sustained oscillations in the oxidation of methane. We have compared this mechanism with the detailed 18-stage mechanism described previously by Lashina et al. (Kinetics and Catalysis 2012, 53, 374-383). It has been shown that both kinetic mechanisms coupled with a continuous stirred-tank reactor model describe well the oscillatory behavior in the oxidation of methane under non-isothermal conditions.

  19. 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.

  20. Hot-Fire Test Results of an Oxygen/RP-2 Multi-Element Oxidizer-Rich Staged-Combustion Integrated Test Article

    Science.gov (United States)

    Hulka, J. R.; Protz, C. S.; Garcia, C. P.; Casiano, M. J.; Parton, J. A.

    2016-01-01

    As part of the Combustion Stability Tool Development project funded by the Air Force Space and Missile Systems Center, the NASA Marshall Space Flight Center was contracted to assemble and hot-fire test a multi-element integrated test article demonstrating combustion characteristics of an oxygen/hydrocarbon propellant oxidizer-rich staged-combustion engine thrust chamber. Such a test article simulates flow through the main injectors of oxygen/kerosene oxidizer-rich staged combustion engines such as the Russian RD-180 or NK-33 engines, or future U.S.-built engine systems such as the Aerojet-Rocketdyne AR-1 engine or the Hydrocarbon Boost program demonstration engine. For the thrust chamber assembly of the test article, several configurations of new main injectors, using relatively conventional gas-centered swirl coaxial injector elements, were designed and fabricated. The design and fabrication of these main injectors are described in a companion paper at this JANNAF meeting. New ablative combustion chambers were fabricated based on hardware previously used at NASA for testing at similar size and pressure. An existing oxygen/RP-1 oxidizer-rich subscale preburner injector from a previous NASA-funded program, along with existing and new inter-connecting hot gas duct hardware, were used to supply the oxidizer-rich combustion products to the oxidizer circuit of the main injector of the thrust chamber. Results from independent hot-fire tests of the preburner injector in a combustion chamber with a sonic throat are described in companion papers at this JANNAF conference. The resulting integrated test article - which includes the preburner, inter-connecting hot gas duct, main injector, and ablative combustion chamber - was assembled at Test Stand 116 at the East Test Area of the NASA Marshall Space Flight Center. The test article was well instrumented with static and dynamic pressure, temperature, and acceleration sensors to allow the collected data to be used for

  1. A detailed TEM and SEM study of Ni-base alloys oxide scales formed in primary conditions of pressurized water reactor

    International Nuclear Information System (INIS)

    Sennour, Mohamed; Marchetti, Loic; Martin, Frantz; Perrin, Stephane; Molins, Regine; Pijolat, Michele

    2010-01-01

    The oxide film formed on nickel-based alloys in pressurized water reactors (PWR) primary coolant conditions (325 o C, aqueous media) is very thin, in the range of 1-100 nm thick, depending on the surface state and on the corrosion test duration. The nature and the structure of this scale have been investigated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). TEM observations revealed an oxide layer divided in two parts. The internal layer was mainly composed of a continuous spinel layer, identified as a mixed iron and nickel chromite (Ni (1-x) Fe x Cr 2 O 4 ). Moreover, nodules of Cr 2 O 3 , with a size about 5 nm, were present at the interface between this spinel and the alloy. No chromium depletion was observed in the alloy, at the alloy/oxide interface. The external layer is composed of large crystallites corresponding to a spinel structure rich in iron (Ni (1-z) Fe (2+z) O 4 ) resulting from precipitation phenomena. SEM and TEM observations showed a link between the nucleation and/or the growth of crystallites of nickel ferrite and the crystallographic orientation of the substrate. A link between the presence of surface defects and the nucleation of the crystallites was also underlined by SEM observations. Partially hydrated nickel hydroxide, was also observed by TEM in the external scale. Based on these results, some considerations about the mechanism of formation of this oxide layer are discussed.

  2. Coexistence of positive and negative photoconductivity in nickel oxide decorated multiwall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Marín, E. [Departamento de Ingeniería en Metalurgia y Materiales, Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, Ciudad de México 07300 (Mexico); Villalpando, I. [Centro de Investigación para los Recursos Naturales, Salaices, Chihuahua 33941 (Mexico); Trejo-Valdez, M. [Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, México, Ciudad de México 07738 (Mexico); Cervantes-Sodi, F. [Departamento de Física y Matemáticas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, Ciudad de México 01219 (Mexico); Vargas-García, J.R. [Centro de Nanociencias y Micro y Nanotecnologías del Instituto Politécnico Nacional, Ciudad de México 07738 (Mexico); Torres-Torres, C., E-mail: ctorrest@ipn.mx [Sección de Estudios de Posgrado e Investigación, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco, Instituto Politécnico Nacional, Ciudad de México 07738 (Mexico)

    2017-06-15

    Highlights: • Nickel oxide decorated carbon nanotubes were prepared by chemical vapor deposition. • Contrast in photoconductivity phenomena in the nanohybrid was analyzed. • Electrical and nonlinear optical properties were evaluated. • A Wheatstone bridge sensor based metal/carbon nanostructures was proposed. - Abstract: Within this work was explored the influence of nickel oxide decoration on the photoconductive effects exhibited by multiwall carbon nanotubes. Samples in thin film form were prepared by a chemical vapor deposition method. Experiments for evaluating the photo-response of the nanomaterials at 532 nanometers wavelength were undertaken. A contrasting behavior in the photoelectrical characteristics of the decorated nanostructures was analyzed. The decoration technique allowed us to control a decrease in photoconduction of the sample from approximately 100 μmhos/cm to −600 μmhos/cm. Two-wave mixing experiments confirmed an enhancement in nanosecond nonlinearities derived by nickel oxide contributions. It was considered that metallic nanoparticles present a strong responsibility for the evolution of the optoelectronic phenomena in metal/carbon nanohybrids. Impedance spectroscopy explorations indicated that a capacitive behavior correspond to the samples. A potential development of high-sensitive Wheatstone bridge sensors based on the optoelectrical performance of the studied samples was proposed.

  3. Nickel-based anodic electrocatalysts for fuel cells and water splitting

    Science.gov (United States)

    Chen, Dayi

    Our world is facing an energy crisis, so people are trying to harvest and utilize energy more efficiently. One of the promising ways to harvest energy is via solar water splitting to convert solar energy to chemical energy stored in hydrogen. Another of the options to utilize energy more efficiently is to use fuel cells as power sources instead of combustion engines. Catalysts are needed to reduce the energy barriers of the reactions happening at the electrode surfaces of the water-splitting cells and fuel cells. Nickel-based catalysts happen to be important nonprecious electrocatalysts for both of the anodic reactions in alkaline media. In alcohol fuel cells, nickel-based catalysts catalyze alcohol oxidation. In water splitting cells, they catalyze water oxidation, i.e., oxygen evolution. The two reactions occur in a similar potential range when catalyzed by nickel-based catalysts. Higher output current density, lower oxidation potential, and complete substrate oxidation are preferred for the anode in the applications. In this dissertation, the catalytic properties of nickel-based electrocatalysts in alkaline medium for fuel oxidation and oxygen evolution are explored. By changing the nickel precursor solubility, nickel complex nanoparticles with tunable sizes on electrode surfaces were synthesized. Higher methanol oxidation current density is achieved with smaller nickel complex nanoparticles. DNA aggregates were used as a polymer scaffold to load nickel ion centers and thus can oxidize methanol completely at a potential about 0.1 V lower than simple nickel electrodes, and the methanol oxidation pathway is changed. Nickel-based catalysts also have electrocatalytic activity towards a wide range of substrates. Experiments show that methanol, ethanol, glycerol and glucose can be deeply oxidized and carbon-carbon bonds can be broken during the oxidation. However, when comparing methanol oxidation reaction to oxygen evolution reaction catalyzed by current nickel

  4. Ultra High Electrical Performance of Nano Nickel Oxide and Polyaniline Composite Materials

    Directory of Open Access Journals (Sweden)

    Xiaomin Cai

    2017-07-01

    Full Text Available The cooperative effects between the PANI (polyaniline/nano-NiO (nano nickel oxide composite electrode material and redox electrolytes (potassium iodide, KI for supercapacitor applications was firstly discussed in this article, providing a novel method to prepare nano-NiO by using β-cyelodextrin (β-CD as the template agent. The experimental results revealed that the composite electrode processed a high specific capacitance (2122.75 F·g−1 at 0.1 A·g−1 in 0.05 M KI electrolyte solution, superior energy density (64.05 Wh·kg−1 at 0.2 A·g−1 in the two-electrode system and excellent cycle performance (86% capacitance retention after 1000 cycles at 1.5 A·g−1. All those ultra-high electrical performances owe to the KI active material in the electrolyte and the PANI coated nano-NiO structure.

  5. Nicotinamide N-Methyltransferase Suppression Participates in Nickel-Induced Histone H3 Lysine9 Dimethylation in BEAS-2B Cells

    Directory of Open Access Journals (Sweden)

    Qian Li

    2017-04-01

    Full Text Available Background: Nickel compounds are well-established human carcinogens with weak mutagenic activity. Histone methylation has been proposed to play an important role in nickel-induced carcinogenesis. Nicotinamide N-methyltransferase (NNMT decreases histone methylation in several cancer cells by altering the cellular ratio of S-adenosylmethionine (SAM to S-adenosylhomocysteine (SAH. However, the role of NNMT in nickel-induced histone methylation remains unclear. Methods: BEAS-2B cells were exposed to different concentrations of nickel chloride (NiCl2 for 72 h or 200 μM NiCl2 for different time periods. Histone H3 on lysine 9 (H3K9 mono-, di-, and trimethylation and NNMT protein levels were measured by western blot analysis. Expressions of NNMT mRNA and the H3k9me2-associated genes, mitogen-activated protein kinase 3 (MAP2K3 and dickkopf1 (DKK1, were determined by qPCR analysis. The cellular ratio of nicotinamide adenine dinucleotide (NAD+ to reduced NAD (NADH and SAM/SAH ratio were determined. Results: Exposure of BEAS-2B cells to nickel increased H3K9 dimethylation (H3K9me2, suppressed the expressions of H3K9me2-associated genes (MAP2K3 and DKK1, and induced NNMT repression at both the protein and mRNA levels. Furthermore, over-expression of NNMT inhibited nickel-induced H3K9me2 and altered the cellular SAM/SAH ratio. Additionally, the NADH oxidant phenazine methosulfate (PMS not only reversed the nickel-induced reduction in NAD+/NADH but also inhibited the increase in H3K9me2. Conclusions: These findings indicate that the repression of NNMT may underlie nickel-induced H3K9 dimethylation by altering the cellular SAM/SAH ratio.

  6. Oxidation mechanism of nickel particles studied in an environmental transmission electron microscope

    DEFF Research Database (Denmark)

    Jeangros, Q.; Hansen, Thomas Willum; Wagner, Jakob Birkedal

    2014-01-01

    The oxidation of nickel particles was studied in situ in an environmental transmission electron microscope in 3.2 mbar of O2 between ambient temperature and 600°C. Several different transmission electron microscopy imaging techniques, electron diffraction and electron energy-loss spectroscopy were...... diffusion of Ni2+ along NiO grain boundaries, self-diffusion of Ni2+ ions and vacancies, growth of NiO grains and nucleation of voids at Ni/NiO interfaces. We also observed the formation of transverse cracks in a growing NiO film in situ in the electron microscope....

  7. Exploring Lithium-Cobalt-Nickel Oxide Spinel Electrodes for ≥3.5 V Li-Ion Cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eungje; Blauwkamp, Joel; Castro, Fernando C.; Wu, Jinsong; Dravid, Vinayak P.; Yan, Pengfei; Wang, Chongmin; Kim, Soo; Wolverton, Christopher; Benedek, Roy; Dogan, Fulya; Park, Joong Sun; Croy, Jason R.; Thackeray, Michael M.

    2016-10-19

    Recent reports have indicated that a manganese oxide spinel component, when embedded in a relatively small concentration in layered xLi2MnO3(1-x)LiMO2 (M=Ni, Mn, Co) electrode systems, can act as a stabilizer that increases their capacity, rate capability, cycle life, and first-cycle efficiency. These findings prompted us to explore the possibility of exploiting lithiated cobalt oxide spinel stabilizers by taking advantage of (1) the low mobility of cobalt ions relative to manganese and nickel ions in close-packed oxides and (2) their higher potential (~3.6 V vs. Li0) relative to manganese oxide spinels (~2.9 V vs. Li0) for the spinel-to-lithiated spinel electrochemical reaction. In particular, we have revisited the structural and electrochemical properties of lithiated spinels in the LiCo1-xNixO2 (0x0.2) system, first reported almost 25 years ago, by means of high-resolution (synchrotron) X-ray diffraction, transmission electron microscopy, nuclear magnetic resonance spectroscopy, electrochemical cell tests, and theoretical calculations. The results provide a deeper understanding of the complexity of intergrown layered/lithiated spinel LiCo1-xNixO2 structures, when prepared in air between 400 and 800 C, and the impact of structural variations on their electrochemical behavior. These structures, when used in low concentration, offer the possibility of improving the cycling stability, energy, and power of high energy (≥3.5 V) lithium-ion cells.

  8. Batch fabrication of mesoporous boron-doped nickel oxide nanoflowers for electrochemical capacitors

    International Nuclear Information System (INIS)

    Yang, Jing-He; Yu, Qingtao; Li, Yamin; Mao, Liqun; Ma, Ding

    2014-01-01

    Highlights: • A new facile liquid-phase method has been employed for synthesis boron-doped NiO nanoflowers. • The specific surface area of NiO is as high as 200 m 2 g −1 . • NiO nanoflowers exhibit a high specific capacitance of ∼1309 F g −1 at a charge and discharge current density of 3 A g −1 . • NiO nanoflowers have excellent cycling ability and even after 2500 cycles there is no significant reduction in specific capacitance. - Abstract: Boron-doped nickel oxide (B-NiO) nanoflowers are prepared by simple thermal decomposition of nickel hydroxide. B-NiO is porous sphere with a diameter of about 400 nm. B-NiO nanoflowers are composed of approximately 30 nm nanoplates and the thickness of the nanosheets is approximately 3 nm. The specific surface area of the material is as high as 200 m 2 g −1 and the pore size distribution curves of B-NiO has three typical peaks in the range of mesoporous (5 nm, 13 nm and 18 nm). As an electrode for supercapacitors, the crystalline B-NiO nanoflowers have favorable characteristics, for instance, a specific capacitance of 1309 F g −1 at a current density of 3 A g −1 and no significant reduction in Coulombic efficiency after 2500 cycles at 37.5 A g −1 . This remarkable electrochemical performance will make B-NiO nanoflowers a promising electrode material for high performance supercapacitors

  9. Characterization of particulate sol-gel synthesis of LiNi0.8Co0.2O2 via maleic acid assistance with different solvents

    International Nuclear Information System (INIS)

    Zhong, Y.D.; Zhao, X.B.; Cao, G.S.; Tu, J.P.; Zhu, T.J.

    2006-01-01

    Particulate sol-gel LiNi 0.8 Co 0.2 O 2 has been synthesized by a maleic-acid-assisted process using de-ionized water or ethanol as the solvent. A comparison of the effect on these two different solvents was made on the basis of thermal studies, Fourier transform infrared spectroscopy, X-ray diffraction analysis, chemical diffusion coefficients measurement, and electrochemical cyclability tests. An esterification reaction occurred on the xerogel prepared with ethanol as solvent, reducing Ni and Co from their nitrate salts. LiNi 0.8 Co 0.2 O 2 grew at the expense of Li 2 CO 3 , NiO, and CoO during calcination. Better results of capacity and cyclability were obtained in a DI-water-solvent sample associated with a larger interslab thickness between O-Li-O and lower Ni occupancy on the Li site. The activation energy for the calcinations of DI-water-solvent sample is one-half of that of the ethanol-solvent one, which could be the reason for its better properties. Chemical diffusion coefficients of Li + ion are of the same order 10 -10 cm 2 /s, is not affected by the solvents used and/or the temperature raise to 55 deg. C

  10. Nickel oxide film with open macropores fabricated by surfactant-assisted anodic deposition for high capacitance supercapacitors.

    Science.gov (United States)

    Wu, Mao-Sung; Wang, Min-Jyle

    2010-10-07

    Nickel oxide film with open macropores prepared by anodic deposition in the presence of surfactant shows a very high capacitance of 1110 F g(-1) at a scan rate of 10 mV s(-1), and the capacitance value reduces to 950 F g(-1) at a high scan rate of 200 mV s(-1).

  11. Corrosion of nickel and stainless steels in concentrated lithium hydroxide solutions

    International Nuclear Information System (INIS)

    Graydon, J.W.; Kirk, D.W.

    1990-06-01

    The corrosion behaviour of four alloys in 3 and 5 mol/L lithium hydroxide solutions under a hydrogen atmosphere at 95 degrees C was investigated. Corrosion of Nickel 200 and the stainless steels 316, 316L, and E-Brite 26-1 was assessed in two sets of immersion tests lasting 10 and 136 days. Corrosion rates were determined by weight loss, susceptibility to stress corrosion cracking was evaluated using U-bends, and the details of the corrosion process were studied on specimens with a mirror finish using light and electron microscopy, x-ray spectrometry and mapping, and x-ray diffraction. The long term corrosion rates were low for all alloys ( 2 , β-LiFeO 2 , and a very iron-rich β-LiFe 5 0 8 . The passivating layer on the nickel was Ni(OH) 2 . The underlying metal corroded evenly except for the 316 stainless steels. These showed a uniform intergranular corrosion with minor drop-out of smaller grains likely because of segregation of impurities to the grain boundaries. The walls of these intergranular crevices were covered with a passivating layer of chromium oxide. (8 figs., 5 tabs., 11 refs.)

  12. Comparative cytotoxic response of nickel ferrite nanoparticles in human liver HepG2 and breast MFC-7 cancer cells.

    Science.gov (United States)

    Ahamed, Maqusood; Akhtar, Mohd Javed; Alhadlaq, Hisham A; Khan, M A Majeed; Alrokayan, Salman A

    2015-09-01

    Nickel ferrite nanoparticles (NPs) have received much attention for their potential applications in biomedical fields such as magnetic resonance imaging, drug delivery and cancer hyperthermia. However, little is known about the toxicity of nickel ferrite NPs at the cellular and molecular levels. In this study, we investigated the cytotoxic responses of nickel ferrite NPs in two different types of human cells (i.e., liver HepG2 and breast MCF-7). Nickel ferrite NPs induced dose-dependent cytotoxicity in both types of cells, which was demonstrated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT), neutral red uptake (NRU) and lactate dehydrogenase (LDH) assays. Nickel ferrite NPs were also found to induce oxidative stress, which was evident by the depletion of glutathione and the induction of reactive oxygen species (ROS) and lipid peroxidation. The mitochondrial membrane potential due to nickel ferrite NP exposure was also observed. The mRNA levels for the tumor suppressor gene p53 and the apoptotic genes bax, CASP3 and CASP9 were up-regulated, while the anti-apoptotic gene bcl-2 was down-regulated following nickel ferrite NP exposure. Furthermore, the activities of apoptotic enzymes (caspase-3 and caspase-9) were also higher in both types of cells treated with nickel ferrite NPs. Cytotoxicity induced by nickel ferrite was efficiently prevented by N-acetyl cysteine (ROS scavenger) treatment, which suggested that oxidative stress might be one of the possible mechanisms of nickel ferrite NP toxicity. We also observed that MCF-7 cells were slightly more susceptible to nickel ferrite NP exposure than HepG2 cells. This study warrants further investigation to explore the potential mechanisms of different cytotoxic responses of nickel ferrite NPs in different cell lines. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The Importance of some weeds for the survival of Fusarium oxysporum Schl. f.sp. lini (Boll. Snyd.

    Directory of Open Access Journals (Sweden)

    Barbara Łacicowa

    2014-08-01

    Full Text Available The studies were caried out to determine the importance of some weeds occurrence in the flax monoculture the survival of Fusarium oxysporum f. sp. lini. It appearet that the roots of Veronica persica, Stellaria media, Lamium purpureum, Capsella bursa-pastoris and Sonchus arvensis were colonized by Fusarium oxysporum f. sp. lini. V. persica especially has, a profitable influence on the survival of F. oxysporum f. sp. lini. However. C. hursa-pastoris and S. arvensis stimulate the growth of fungi of the genera Trichoderma. which limites the occurrence of F. oxysporum f. sp. lini in the soil.

  14. Defect physics vis-à-vis electrochemical performance in layered mixed-metal oxide cathode materials

    Science.gov (United States)

    Hoang, Khang; Johannes, Michelle

    Layered mixed-metal oxides with different compositions of (Ni,Co,Mn) [NCM] or (Ni,Co,Al) [NCA] have been used in commercial lithium-ion batteries. Yet their defect physics and chemistry is still not well understood, despite having important implications for the electrochemical performance. In this presentation, we report a hybrid density functional study of intrinsic point defects in the compositions LiNi1/3Co1/3Mn1/3O2 (NCM1/3) and LiNi1/3Co1/3Al1/3O2 (NCA1/3) which can also be regarded as model compounds for NCM and NCA. We will discuss defect landscapes in NCM1/3 and NCA1/3 under relevant synthesis conditions with a focus on the formation of metal antisite defects and its implications on the electrochemical properties and ultimately the design of NCM and NCA cathode materials.

  15. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    International Nuclear Information System (INIS)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-01-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO 4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  16. Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

    Science.gov (United States)

    Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

    2010-10-01

    A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

  17. Band gap narrowing and fluorescence properties of nickel doped SnO2 nanoparticles

    International Nuclear Information System (INIS)

    Ahmed, Arham S.; Shafeeq, M. Muhamed; Singla, M.L.; Tabassum, Sartaj; Naqvi, Alim H.; Azam, Ameer

    2011-01-01

    Nickel-doped tin oxide nanoparticles (sub-5 nm size) with intense fluorescence emission behavior have been synthesized by sol-gel route. The structural and compositional analysis has been carried out by using XRD, TEM, FESEM and EDAX. The optical absorbance spectra indicate a band gap narrowing effect and it was found to increase with the increase in nickel concentration. The band gap narrowing at low dopant concentration ( 2 -SnO 2-x alloying effect and for higher doping it may be due to the formation of defect sub-bands below the conduction band.

  18. Applications of x ray absorption fine structure to the in situ study of the effect of cobalt in nickel hydrous oxide electrodes for fuel cells and rechargeable batteries

    Science.gov (United States)

    Kim, Sunghyun; Tryk, Donald A.; Scherson, Daniel A.; Antonio, Mark R.

    1993-01-01

    Electronic and structural aspects of composite nickel-cobalt hydrous oxides have been examined in alkaline solutions using in situ X-ray absorption fine structure (XAFS). The results obtained have indicated that cobalt in this material is present as cobaltic ions regardless of the oxidation state of nickel in the lattice. Furthermore, careful analysis of the Co K-edge Extended X-ray absorption fine structure data reveals that the co-electrodeposition procedure generates a single phase, mixed metal hydrous oxide, in which cobaltic ions occupy nickel sites in the NiO2 sheet-like layers and not two intermixed phases each consisting of a single metal hydrous oxide.

  19. Austenitic stainless steel alloys with high nickel contents in high temperature liquid metal systems

    International Nuclear Information System (INIS)

    Konvicka, H.R.; Schwarz, N.F.

    1981-01-01

    Fe-Cr-Ni base alloys (nickel content: from 15 to 70 wt%, Chromium content: 15 wt%, iron: balance) together with stainless steel (W.Nr. 1.4981) have been exposed to flowing liquid sodium at 730 0 C in four intervals up to a cumulative exposure time of 1500 hours. Weight change data and the results of post-exposition microcharacterization of specimens are reported. The corrosion rates increase with increasing nickel content and tend to become constant after longer exposure times for each alloy. The corrosion rate of stainless steel is considerably reduced due to the presence of the base alloys. Different kinetics of nickel poor (up to 35% nickel) and nickel rich (> 50% nickel) alloys and nickel transport from nickel rich to nickel poor material is observed. (orig.)

  20. The genome sequence and effector complement of the flax rust pathogen Melampsora lini

    Directory of Open Access Journals (Sweden)

    Adnane eNemri

    2014-03-01

    Full Text Available Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp. Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimise parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analysed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote

  1. The genome sequence and effector complement of the flax rust pathogen Melampsora lini.

    Science.gov (United States)

    Nemri, Adnane; Saunders, Diane G O; Anderson, Claire; Upadhyaya, Narayana M; Win, Joe; Lawrence, Gregory J; Jones, David A; Kamoun, Sophien; Ellis, Jeffrey G; Dodds, Peter N

    2014-01-01

    Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed most extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp). Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimize parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analyzed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote infection on their

  2. Nickel oxide crystalline nano flakes: synthesis, characterization and their use as anode in lithium-ion batteries

    DEFF Research Database (Denmark)

    Ahmadi, Majid; Younesi, Reza; Vegge, Tejs

    2014-01-01

    Nickel oxide crystalline nano flakes (NONFs)—only about 10 nm wide—were produced using a simple and inexpensive chemistry method followed by a short annealing in ambient air. In a first step, Ni(OH)2 sheets were synthesized by adding sodium hydroxide (NaOH) drop-wise in a Ni(NO3)2 aqueous solutio...

  3. A facile cathode design combining Ni-rich layered oxides with Li-rich layered oxides for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Song, Bohang; Li, Wangda; Yan, Pengfei; Oh, Seung-Min; Wang, Chong-Min; Manthiram, Arumugam

    2016-09-01

    A facile synthesis method was developed to prepare xLi2MnO3·(1-x)LiNi0.7Co0.15Mn0.15O2 (x = 0, 0.03, 0.07, 0.10, 0.20, and 0.30 as molar ratio) cathode materials, combining the advantages of high specific capacity from Ni-rich layered phase and surface chemical stability from Li-rich layered phase. X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM) and electrochemical charge/discharge performance confirm the formation of a Li-rich layered phase with C2/m symmetry. Most importantly, high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) reveals a spatial relationship that Li-rich nano-domain islands are integrated into a conventional Ni-rich layered matrix (R$\\bar{3}$m). This is the first time that Li-rich phase has been directly observed inside a particle at the nano-scale, when the overall composition of layered compounds (Li1NixMnyM1-x-y-δO2, M refers to transition metal elements) is Ni-rich (x > 0.5) rather than Mn-rich (y > 0.5). Remarkably, xLi2MnO3·(1-x)LiNi0.7Co0.15Mn0.15O2 cathode with optimized x value shows superior electrochemical performance at C/3, i.e., 170 mA h g-1 with 90.3 % of capacity retention after 400 cycles at 25 °C and 164 mA h g-1 with 81.3 % capacity retention after 200 cycles at 55 °C.

  4. Adsorption of heavy metal ion from aqueous solution by nickel oxide nano catalyst prepared by different methods

    Directory of Open Access Journals (Sweden)

    Amira M. Mahmoud

    2015-03-01

    Full Text Available Environmental pollution by heavy metal is arising as the most endangering tasks to both water sources and atmosphere quality today. The treatment of heavy metals is of special concern due to their recalcitrance and persistence in the environment. To limit the spread of the heavy metals within water sources, nickel oxide nanoparticles adsorbents were synthesized and characterized with the aim of removal of one of the aggressive heavy elements, namely; lead ions. Nano nickel oxide adsorbents were prepared using NaOH and oxalic acid dissolved in ethanol as precursors. The results indicated that adsorption capacity of Pb(II ion by NiO-org catalyst is favored than that prepared using NaOH as a precipitant. Nickel oxide nanoparticles prepared by the two methods were characterized structurally and chemically through XRD, DTA, TGA, BET and FT-IR. Affinity and efficiency sorption parameters of the solid nano NiO particles, such as; contact time, initial concentration of lead ions and the dosage of NiO nano catalyst and competitive adsorption behaviors were studied. The results showed that the first-order reaction law fit the reduction of lead ion, also showed good linear relationship with a correlation coefficient (R2 larger than 0.9.

  5. Porous nickel hydroxide-manganese dioxide-reduced graphene oxide ternary hybrid spheres as excellent supercapacitor electrode materials.

    Science.gov (United States)

    Chen, Hao; Zhou, Shuxue; Wu, Limin

    2014-06-11

    This paper reports the first nickel hydroxide-manganese dioxide-reduced graphene oxide (Ni(OH)2-MnO2-RGO) ternary hybrid sphere powders as supercapacitor electrode materials. Due to the abundant porous nanostructure, relatively high specific surface area, well-defined spherical morphology, and the synergetic effect of Ni(OH)2, MnO2, and RGO, the electrodes with the as-obtained Ni(OH)2-MnO2-RGO ternary hybrid spheres as active materials exhibited significantly enhanced specific capacitance (1985 F·g(-1)) and energy density (54.0 Wh·kg(-1)), based on the total mass of active materials. In addition, the Ni(OH)2-MnO2-RGO hybrid spheres-based asymmetric supercapacitor also showed satisfying energy density and electrochemical cycling stability.

  6. Electrodeposited nickel oxide and graphene modified carbon ionic liquid electrode for electrochemical myglobin biosensor

    International Nuclear Information System (INIS)

    Sun, Wei; Gong, Shixing; Deng, Ying; Li, Tongtong; Cheng, Yong; Wang, Wencheng; Wang, Lei

    2014-01-01

    By using ionic liquid 1-hexylpyridinium hexafluorophosphate based carbon ionic liquid electrode (CILE) as the substrate electrode, graphene (GR) and nickel oxide (NiO) were in situ electrodeposited step by step to get a NiO/GR nanocomposite modified CILE. Myoglobin (Mb) was further immobilized on the surface of NiO/GR/CILE with a Nafion film to get the electrochemical sensor denoted as Nafion/Mb/NiO/GR/CILE. Cyclic voltammetric experiments indicated that a pair of well-defined quasi-reversible redox peaks appeared in pH 3.0 phosphate buffer solution with the formal peak potential (E 0′ ) located at − 0.188 V (vs. SCE), which was the typical characteristics of Mb Fe(III)/Fe(II) redox couples. So the direct electron transfer of Mb was realized and promoted due to the presence of the NiO/GR nanocomposite on the electrode. Based on the cyclic voltammetric data, the electrochemical parameters of Mb on the modified electrode were calculated. The Mb modified electrode showed an excellent electrocatalytic activity towards the reduction of different substrates including trichloroacetic acid and H 2 O 2 . Therefore a third-generation electrochemical Mb biosensor based on NiO/GR/CILE was constructed with good stability and reproducibility. - Highlights: • Graphene and nickel oxide nanocomposites were prepared by electrodeposition. • Electrochemical myoglobin sensor was prepared on a nanocomposite modified electrode. • Direct electrochemistry and electrocatalysis of myglobin were realized

  7. Improvement of solvents for chemical decontamination: nickel ferrites removal

    International Nuclear Information System (INIS)

    Figueroa, Carlos A.; Morando, Pedro J.; Blesa, Miguel A.

    1999-01-01

    Carboxylic acids are usually included in commercial solvents for the chemical cleaning and decontamination of metal surfaces from the oxide layers grown and/or deposited from high temperature water by corrosive process. In particular oxalic acid is included in second path of AP-Citrox method. However, in some cases, their use shows low efficiency. This fact is attributed to the special passivity of the mixed oxides as nickel ferrites. This work reports a kinetic study of dissolution of a synthetic nickel ferrite (NiFe 2 O 4 ) confronted with simple oxides (NiO and Fe 2 O 3 ) in mineral acids and oxalic acid. The dissolution factor and reaction rate were determined in several conditions (reactive concentrations, pH and added ferrous ions). Experimental data of dissolution (with and without Fe(II) added) show a congruent kinetic regime. Pure nickel oxide (NiO) is rather resistant to the attack by oxalic acid solutions, and ferrous ions do not accelerate dissolution. In fact, nickel oxide dissolves better by oxidative attack that takes advantage of the higher lability of Ni 3+ . It may be concluded that oxalic acid operates to dissolve iron, and the ensuing disruption of the solid framework accelerates the release of nickel. Our results point to use more reactive solvents in iron from mixed oxides and to the possibility of using one stage decontamination method. (author)

  8. High-performance binder-free supercapacitor electrode by direct growth of cobalt-manganese composite oxide nansostructures on nickel foam

    OpenAIRE

    Jiang, Shulan; Shi, Tielin; Long, Hu; Sun, Yongming; Zhou, Wei; Tang, Zirong

    2014-01-01

    A facile approach composed of hydrothermal process and annealing treatment is proposed to directly grow cobalt-manganese composite oxide ((Co,Mn)3O4) nanostructures on three-dimensional (3D) conductive nickel (Ni) foam for a supercapacitor electrode. The as-fabricated porous electrode exhibits excellent rate capability and high specific capacitance of 840.2 F g-1 at the current density of 10 A g-1, and the electrode also shows excellent cycling performance, which retains 102% of its initial d...

  9. High-performance lithium-rich layered oxide materials: Effects of chelating agents on microstructure and electrochemical properties

    International Nuclear Information System (INIS)

    Li, Lingjun; Xu, Ming; Chen, Zhaoyong; Zhou, Xiang; Zhang, Qiaobao; Zhu, Huali; Wu, Chun; Zhang, Kaili

    2015-01-01

    The mechanisms and effects of three typical chelating agents, namely glucose, citric acid and sucrose on the sol-gel synthesis process, electrochemical degradation and structural evolution of 0.5Li 2 MnO 3 ·0.5LiNi 0.5 Co 0.2 Mn 0.3 O 2 (LLMO) materials are systematically compared for the first time. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy analysis indicate that the sample synthesized from sucrose owns well structure, homogenous distribution, low Ni 3+ concentration and good surface structural stability during cycling, respectively. Electrochemical tests further prove that the LLMO material obtained from sucrose maintains 258.4 mAh g −1 with 94.8% capacity retention after 100 cycles at 0.2 C. The superior electrochemical performance can be ascribed to the exceptional complexing mechanism of sucrose, compared to those of the glucose and citric acid. Namely, one mole sucrose can be hydrolyzed into two different monosaccharides and further chelates three M (Li, Ni, Co and Mn) ions to form a more uniform ion-chelated matrix during sol-gel process. This discovery is an important step towards understanding the selection criterion of chelating agents for sol-gel method, that chelating agent with excellent complexing capability is beneficial to the distribution, structural stability and electrochemical properties of advanced lithium-rich layered materials

  10. Nickel and cobalt bimetallic hydroxide catalysts for urea electro-oxidation

    International Nuclear Information System (INIS)

    Yan Wei; Wang Dan; Botte, Gerardine G.

    2012-01-01

    Nickel–Cobalt bimetallic hydroxide electrocatalysts, synthesized through a one-step electrodeposition method, were evaluated for the oxidation of urea in alkaline conditions with the intention of reducing the oxidation overpotential for this reaction. The Nickel–Cobalt bimetallic hydroxide catalysts were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), Raman spectroscopy, cyclic voltammetry (CV), and polarization techniques. A significant reduction in the overpotential (150 mV) of the reaction was observed with the Nickel–Cobalt bimetallic hydroxide electrode (ca. 43% Co content) when compared to a nickel hydroxide electrode. The decrease of the urea oxidation potential on the Nickel–Cobalt bimetallic hydroxide electrodes reveals great potential for future applications of urea electro-oxidation, including wastewater remediation, hydrogen production, sensors, and fuel cells.

  11. Investigation on reactivity of iron nickel oxides in chemical looping dry reforming

    International Nuclear Information System (INIS)

    Huang, Zhen; He, Fang; Chen, Dezhen; Zhao, Kun; Wei, Guoqiang; Zheng, Anqing; Zhao, Zengli; Li, Haibin

    2016-01-01

    Iron nickel oxides as oxygen carriers were investigated to clarify the reaction mechanism of NiFe_2O_4 material during the chemical looping dry reforming (CLDR) process. The thermodynamic analysis showed that metallic Fe can be oxidized into Fe_3O_4 by CO_2, but metallic Ni cannot. The oxidizability of the four oxygen carriers was in the order of NiO > synthetic NiFe_2O_4 spinel > NiO-Fe_2O_3 mixed oxides > Fe_2O_3, and the reducibility sequence of their reduced products was synthetic NiFe_2O_4 spinel > NiO-Fe_2O_3 mixed oxides > Fe_2O_3 > NiO. The NiO showed the best oxidizability but it was easy to cause CH_4 cracking and its reduced product (Ni) did not recover lattice oxygen under CO_2 atmosphere. It only produced 74 mL CO for 1 g Fe_2O_3 during the CO_2 reforming because of its weak oxidizability. The Redox ability of synthetic NiFe_2O_4 was obvious higher than that of NiO-Fe_2O_3 mixed oxides due to the synergistic effect of metallic Fe-Ni in the spinel structure. 1 g synthetic NiFe_2O_4 can produce 238 mL CO, which was twice higher than that of 1 g NiO-Fe_2O_3 mixed oxides (111 mL). A part of Fe element was divorced from the NiFe_2O_4 spinel structure after one cycle, which was the major reason for degradation of reactivity of NiFe_2O_4 oxygen carrier. - Highlights: • A synergistic effect of Fe/Ni can improve the reactivity of oxygen carrier (OC). • The oxidizability sequence of four OCs is NiO > NiFe_2O_4 > mixed NiO + Fe_2O_3 > Fe_2O_3. • The reducibility sequence of four OCs is NiFe_2O_4 > mixed NiO + Fe_2O_3 > Fe_2O_3 > NiO. • The formation of Fe (Ni) alloy phase facilitates more CO_2 reduced into CO. • Part of Fe is divorced from the spinel structure, leading to the degeneration of OC reactivity.

  12. Nickel Nanowire@Porous NiCo{sub 2}O{sub 4} Nanorods Arrays Grown on Nickel Foam as Efficient Pseudocapacitor Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Houzhao; Li, Lang; Zhang, Jun; Liu, Xiang; Wang, Hanbin; Wang, Hao, E-mail: nanoguy@126.com [Faculty of Physics and Electronic Science, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Laboratory of Ferro & Piezoelectric Materials and Devices, Hubei University, Wuhan (China)

    2017-12-13

    A three dimensional hierarchical nanostructure composed of nickel nanowires and porous NiCo{sub 2}O{sub 4} nanorods arrays on the surface of nickel foam is successfully fabricated by a facile route. In this structure, the nickel nanowires are used as core materials to support high-pseudocapacitance NiCo{sub 2}O{sub 4} nanorods and construct the well-defined NiCo{sub 2}O{sub 4} nanorods shell/nickel nanowires core hierarchical structure on nickel foam. Benefiting from the participation of nickel nanowires, the nickel nanowire@NiCo{sub 2}O{sub 4}/Ni foam electrode shows a high areal specific capacitance (7.4 F cm{sup −2} at 5 mA cm{sup −2}), excellent rate capability (88.04% retained at 100 mA cm{sup −2}), and good cycling stability (74.08% retained after 1,500 cycles). The superior electrochemical properties made it promising as electrode for supercapacitors.

  13. Synthesis of Complex-Alloyed Nickel Aluminides from Oxide Compounds by Aluminothermic Method

    Directory of Open Access Journals (Sweden)

    Victor Gostishchev

    2018-06-01

    Full Text Available This paper deals with the investigation of complex-alloyed nickel aluminides obtained from oxide compounds by aluminothermic reduction. The aim of the work was to study and develop the physicochemical basis for obtaining complex-alloyed nickel aluminides and their application for enhancing the properties of coatings made by electrospark deposition (ESD on steel castings, as well as their use as grain refiners for tin bronze. The peculiarities of microstructure formation of master alloys based on the Al–TM (transition metal system were studied using optical, electronic scanning microscopy and X-ray spectral microanalysis. There were regularities found in the formation of structural components of aluminum alloys (Ni–Al, Ni-Al-Cr, Ni-Al-Mo, Ni-Al-W, Ni-Al-Ti, Ni-Cr-Mo-W, Ni-Al-Cr-Mo-W-Ti, Ni-Al-Cr-V, Ni-Al-Cr-V-Mo and changes in their microhardness, depending on the composition of the charge, which consisted of oxide compounds, and on the amount of reducing agent (aluminum powder. It is shown that all the alloys obtained are formed on the basis of the β phase (solid solution of alloying elements in nickel aluminide and quasi-eutectic, consisting of the β′ phase and intermetallics of the alloying elements. The most effective alloys, in terms of increasing microhardness, were Al-Ni-Cr-Mo-W (7007 MPa and Al-Ni-Cr-V-Mo (7914 MPa. The perspective is shown for applying the synthesized intermetallic master alloys as anode materials for producing coatings by electrospark deposition on steel of C1030 grade. The obtained coatings increase the heat resistance of steel samples by 7.5 times, while the coating from NiAl-Cr-Mo-W alloy remains practically nonoxidized under the selected test conditions. The use of NiAl intermetallics as a modifying additive (0.15 wt. % in tin bronze allows increasing the microhardness of the α-solid solution by 1.9 times and the microhardness of the eutectic (α + β phase by 2.7 times.

  14. Structural and chemical degradation mechanisms of pure YSZ and its components ZrO2 and Y2O3 in carbon-rich fuel gases.

    Science.gov (United States)

    Köck, Eva-Maria; Kogler, Michaela; Götsch, Thomas; Klötzer, Bernhard; Penner, Simon

    2016-05-25

    Structural and chemical degradation mechanisms of metal-free yttria stabilized zirconia (YSZ-8, 8 mol% Y2O3 in ZrO2) in comparison to its pure oxidic components ZrO2 and Y2O3 have been studied in carbon-rich fuel gases with respect to coking/graphitization and (oxy)carbide formation. By combining operando electrochemical impedance spectroscopy (EIS), operando Fourier-transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS), the removal and suppression of CH4- and CO-induced carbon deposits and of those generated in more realistic fuel gas mixtures (syngas, mixtures of CH4 or CO with CO2 and H2O) was examined under SOFC-relevant conditions up to 1273 K and ambient pressures. Surface-near carbidization is a major problem already on the "isolated" (i.e. Nickel-free) cermet components, leading to irreversible changes of the conduction properties. Graphitic carbon deposition takes place already on the "isolated" oxides under sufficiently fuel-rich conditions, most pronounced in the pure gases CH4 and CO, but also significantly in fuel gas mixtures containing H2O and CO2. For YSZ, a comparative quantification of the total amount of deposited carbon in all gases and mixtures is provided and thus yields favorable and detrimental experimental approaches to suppress the carbon formation. In addition, the effectivity and reversibility of removal of the coke/graphite layers was comparably studied in the pure oxidants O2, CO2 and H2O and their effective contribution upon addition to the pure fuel gases CO and CH4 verified.

  15. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes II. Steam:carbon ratio and current density

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    For the second part of a two part publication, coking thresholds with respect to molar steam:carbon ratio (SC) and current density in nickel-based solid oxide fuel cells were determined. Anode-supported button cell samples were exposed to 2-component and 5-component gas mixtures with 1 ≤ SC ≤ 2 and zero fuel utilization for 10 h, followed by measurement of the resulting carbon mass. The effect of current density was explored by measuring carbon mass under conditions known to be prone to coking while increasing the current density until the cell was carbon-free. The SC coking thresholds were measured to be ∼1.04 and ∼1.18 at 600 and 700 °C, respectively. Current density experiments validated the thresholds measured with respect to fuel utilization and steam:carbon ratio. Coking thresholds at 600 °C could be predicted with thermodynamic equilibrium calculations when the Gibbs free energy of carbon was appropriately modified. Here, the Gibbs free energy of carbon on nickel-based anode support cermets was measured to be -6.91 ± 0.08 kJ mol-1. The results of this two part publication show that thermodynamic equilibrium calculations with appropriate modification to the Gibbs free energy of solid-phase carbon can be used to predict coking thresholds on nickel-based anodes at 600-700 °C.

  16. Influence of Nitinol wire surface treatment on oxide thickness and composition and its subsequent effect on corrosion resistance and nickel ion release.

    Science.gov (United States)

    Clarke, B; Carroll, W; Rochev, Y; Hynes, M; Bradley, D; Plumley, D

    2006-10-01

    Medical implants and devices are now used successfully in surgical procedures on a daily basis. Alloys of nickel and titanium, and in particular Nitinol are of special interest in the medical device industry, because of their shape memory and superelastic properties. The corrosion behavior of nitinol in the body is also of critical importance because of the known toxicological effects of nickel. The stability of a NiTi alloy in the physiological environment is dependant primarily on the properties of the mostly TiO(2) oxide layer that is present on the surface. For the present study, a range of nitinol wires have been prepared using different drawing processes and a range of surface preparation procedures. It is clear from the results obtained that the wire samples with very thick oxides also contain a high nickel content in the oxide layer. The untreated samples with the thicker oxides show the lowest pitting potential values and greater nickel release in both long and short-term experiments. It was also found that after long-term immersion tests breakdown potentials increased for samples that exhibited lower values initially. From these results it would appear that surface treatment is essential for the optimum bioperformance of nitinol. (c) 2006 Wiley Periodicals, Inc

  17. Cold laser machining of nickel-yttrium stabilised zirconia cermets: Composition dependence

    International Nuclear Information System (INIS)

    Sola, D.; Gurauskis, J.; Pena, J.I.; Orera, V.M.

    2009-01-01

    Cold laser micromachining efficiency in nickel-yttrium stabilised zirconia cermets was studied as a function of cermet composition. Nickel oxide-yttrium stabilised zirconia ceramic plates obtained via tape casting technique were machined using 8-25 ns pulses of a Nd: YAG laser at the fixed wavelength of 1.064 μm and a frequency of 1 kHz. The morphology of the holes, etched volume, drill diameter, shape and depth were evaluated as a function of the processing parameters such as pulse irradiance and of the initial composition. The laser drilling mechanism was evaluated in terms of laser-material interaction parameters such as beam absorptivity, material spallation and the impact on the overall process discussed. By varying the nickel oxide content of the composite the optical absorption (-value is greatly modified and significantly affected the drilling efficiency of the green state ceramic substrates and the morphology of the holes. Higher depth values and improved drilled volume upto 0.2 mm 3 per pulse were obtained for substrates with higher optical transparency (lower optical absorption value). In addition, a laser beam self-focussing effect is observed for the compositions with less nickel oxide content. Holes with average diameter from 60 μm to 110 μm and upto 1 mm in depth were drilled with a high rate of 40 ms per hole while the final microstructure of the cermet obtained by reduction of the nickel oxide-yttrium stabilised zirconia composites remained unchanged.

  18. Novel C-2 epimerization of aldoses promoted by nickel(II) diamine complexes, involving a stereospecific pinacol-type 1,2-carbon shift

    International Nuclear Information System (INIS)

    Tanase, Tomoaki; Shimizu, Fumihiko; Kuse, Manabu; Yano, Shigenobu; Hidai, Masanobu; Yoshikawa, Sadao

    1988-01-01

    The newly discovered C-2 epimerization of aldoses promoted by nickel(II) diamine complexes has been investigated in detail by using 13 C-enriched D-glucose, 13 C NMR spectroscopy, and EXAFS (extended x-ray absorption fine structure) analysis. Aldoses treated with nickel(II) diamine complexes (diamine = N,N,N'-trimethylethylenediamine (N,N,N'-Me 3 en), N,N,N',N'-tetramethylethylenediamine (N,N,N',N'-Me 4 en), etc.) in methanolic solutions were rapidly (60 degree C, 3-5 min) epimerized at C-2 to give equilibrium mixtures where the ratio of C-2 epimers shifts to the side of the naturally rare mannose-type aldoses (having the cis arrangement of C-2 and C-3 hydroxyl groups) compared with those in the thermodynamic equilibrium states. The epimerization product of D-[1- 13 C]glucose was exclusively D-[2- 13 C]mannose, demonstrating that the reaction involves a stereospecific 1,2-shift of the carbon skeleton resulting in inversion of configuration at C-2. Furthermore, the absorption and circular dichroism spectra of the reaction solutions indicated the presence of an intermediate nickel(II) complex containing both diamine and sugar components, which was directly revealed by EXAFS analysis to be a mononuclear nickel(II) complex having octahedral coordination geometry. All these observations strongly suggest that the C-2 epimerization proceeds through an intermediate mononuclear nickel(II) complex, where the carbinolamine-like adduct of aldose with diamine in an open-chain form is epimerized at C-2 by a stereospecific rearrangement of the carbon skeleton or a pinacol-type rearrangement involving a cyclic transition state. 44 refs., 5 figs., 4 tabs

  19. Nickel complexes of o-amidochalcogenophenolate(2-)/o-iminochalcogenobenzosemiquinonate(1-) pi-radical: synthesis, structures, electron spin resonance, and x-ray absorption spectroscopic evidence.

    Science.gov (United States)

    Hsieh, Chung-Hung; Hsu, I-Jui; Lee, Chien-Ming; Ke, Shyue-Chu; Wang, Tze-Yuan; Lee, Gene-Hsiang; Wang, Yu; Chen, Jin-Ming; Lee, Jyh-Fu; Liaw, Wen-Feng

    2003-06-16

    The preparation of complexes trans-[Ni(-SeC(6)H(4)-o-NH-)(2)](-) (1), cis-[Ni(-TeC(6)H(4)-o-NH-)(2)](-) (2), trans-[Ni(-SC(6)H(4)-o-NH-)(2)](-) (3), and [Ni(-SC(6)H(4)-o-S-)(2)](-) (4) by oxidative addition of 2-aminophenyl dichalcogenides to anionic [Ni(CO)(SePh)(3)](-) proves to be a successful approach in this direction. The cis arrangement of the two tellurium atoms in complex 2 is attributed to the intramolecular Te.Te contact interaction (Te.Te contact distance of 3.455 A). The UV-vis electronic spectra of complexes 1 and 2 exhibit an intense absorption at 936 and 942 nm, respectively, with extinction coefficient epsilon > 10000 L mol(-)(1) cm(-)(1). The observed small g anisotropy, the principal g values at g(1) = 2.036, g(2) = 2.062, and g(3) = 2.120 for 1 and g(1) = 2.021, g(2) = 2.119, and g(3) = 2.250 for 2, respectively, indicates the ligand radical character accompanied by the contribution of the singly occupied d orbital of Ni(III). The X-ray absorption spectra of all four complexes show L(III) peaks at approximately 854.5 and approximately 853.5 eV. This may indicate a variation of contribution of the Ni(II)-Ni(III) valence state. According to the DFT calculation, the unpaired electron of complex 1 and 2 is mainly distributed on the 3d(xz)() orbital of the nickel ion and on the 4p(z)() orbital of selenium (tellurium, 5p(z)()) as well as the 2p(z)() orbital of nitrogen of the ligand. On the basis of X-ray structural data, UV-vis absorption, electron spin resonance, magnetic properties, DFT computation, and X-ray absorption (K- and L-edge) spectroscopy, the monoanionic trans-[Ni(-SeC(6)H(4)-o-NH-)(2)](-) and cis-[Ni(-TeC(6)H(4)-o-NH-)(2)](-) complexes are appositely described as a resonance hybrid form of Ni(III)-bis(o-amidochalcogenophenolato(2-)) and Ni(II)-(o-amidochalcogenophenolato(2-))-(o-iminochalcogenobenzosemiquinonato(1-) pi-radical; i.e., complexes 1 and 2 contain delocalized oxidation levels of the nickel ion and ligands.

  20. Characterization and assessment of dermal and inhalable nickel exposures in nickel production and primary user industries.

    Science.gov (United States)

    Hughson, G W; Galea, K S; Heim, K E

    2010-01-01

    The aim of this study was to measure the levels of nickel in the skin contaminant layer of workers involved in specific processes and tasks within the primary nickel production and primary nickel user industries. Dermal exposure samples were collected using moist wipes to recover surface contamination from defined areas of skin. These were analysed for soluble and insoluble nickel species. Personal samples of inhalable dust were also collected to determine the corresponding inhalable nickel exposures. The air samples were analysed for total inhalable dust and then for soluble, sulfidic, metallic, and oxidic nickel species. The workplace surveys were carried out in five different workplaces, including three nickel refineries, a stainless steel plant, and a powder metallurgy plant, all of which were located in Europe. Nickel refinery workers involved with electrolytic nickel recovery processes had soluble dermal nickel exposure of 0.34 microg cm(-2) [geometric mean (GM)] to the hands and forearms. The GM of soluble dermal nickel exposure for workers involved in packing nickel salts (nickel chloride hexahydrate, nickel sulphate hexahydrate, and nickel hydroxycarbonate) was 0.61 microg cm(-2). Refinery workers involved in packing nickel metal powders and end-user powder operatives in magnet production had the highest dermal exposure (GM = 2.59 microg cm(-2) soluble nickel). The hands, forearms, face, and neck of these workers all received greater dermal nickel exposure compared with the other jobs included in this study. The soluble nickel dermal exposures for stainless steel production workers were at or slightly above the limit of detection (0.02 microg cm(-2) soluble nickel). The highest inhalable nickel concentrations were observed for the workers involved in nickel powder packing (GM = 0.77 mg m(-3)), although the soluble component comprised only 2% of the total nickel content. The highest airborne soluble nickel exposures were associated with refineries using

  1. Disposable Non-Enzymatic Glucose Sensors Using Screen-Printed Nickel/Carbon Composites on Indium Tin Oxide Electrodes

    Directory of Open Access Journals (Sweden)

    Won-Yong Jeon

    2015-12-01

    Full Text Available Disposable screen-printed nickel/carbon composites on indium tin oxide (ITO electrodes (DSPNCE were developed for the detection of glucose without enzymes. The DSPNCE were prepared by screen-printing the ITO substrate with a 50 wt% nickel/carbon composite, followed by curing at 400 °C for 30 min. The redox couple of Ni(OH2/NiOOH was deposited on the surface of the electrodes via cyclic voltammetry (CV, scanning from 0–1.5 V for 30 cycles in 0.1 M NaOH solution. The DSPNCE were characterized by field-emission scanning electron microscopy (FE-SEM, X-ray photoelectron spectroscopy (XPS, and electrochemical methods. The resulting electrical currents, measured by CV and chronoamperometry at 0.65 V vs. Ag/AgCl, showed a good linear response with glucose concentrations from 1.0–10 mM. Also, the prepared electrodes showed no interference from common physiologic interferents such as uric acid (UA or ascorbic acid (AA. Therefore, this approach allowed the development of a simple, disposable glucose biosensor.

  2. Carbon Supported Oxide-Rich Pd-Cu Bimetallic Electrocatalysts for Ethanol Electrooxidation in Alkaline Media Enhanced by Cu/CuOx

    Directory of Open Access Journals (Sweden)

    Zengfeng Guo

    2016-04-01

    Full Text Available Different proportions of oxide-rich PdCu/C nanoparticle catalysts were prepared by the NaBH4 reduction method, and their compositions were tuned by the molar ratios of the metal precursors. Among them, oxide-rich Pd0.9Cu0.1/C (Pd:Cu = 9:1, metal atomic ratio exhibits the highest electrocatalytic activity for ethanol oxidation reaction (EOR in alkaline media. X-ray photoelectron spectroscopy (XPS and high resolution transmission electron microscopy (HRTEM confirmed the existence of both Cu and CuOx in the as-prepared Pd0.9Cu0.1/C. About 74% of the Cu atoms are in their oxide form (CuO or Cu2O. Besides the synergistic effect of Cu, CuOx existed in the Pd-Cu bimetallic nanoparticles works as a promoter for the EOR. The decreased Pd 3d electron density disclosed by XPS is ascribed to the formation of CuOx and the spill-over of oxygen-containing species from CuOx to Pd. The low Pd 3d electron density will decrease the adsorption of CH3COads intermediates. As a result, the electrocatalytic activity is enhanced. The onset potential of oxide-rich Pd0.9Cu0.1/C is negative shifted 150 mV compared to Pd/C. The oxide-rich Pd0.9Cu0.1/C also exhibited high stability, which indicated that it is a candidate for the anode of direct ethanol fuel cells (DEFCs.

  3. Contribution to the study of the oxidation reaction of the carbon oxide in contact with catalysts issued from the decomposition of nickel hydro-aluminates at various temperatures; Contribution a l'etude de la reaction d'oxydation de l'oxyde de carbone au contact des catalyseurs issus de la decomposition a diverses temperatures des hydroaluminates de nickel

    Energy Technology Data Exchange (ETDEWEB)

    Samaane, Mikhail

    1966-09-26

    Addressing the study of the oxidation reaction of carbon oxide which produces carbon dioxide, this research thesis reports the study of this reaction in presence of catalysts (2NiO + Al{sub 2}O{sub 3}, NiAl{sub 2}O{sub 4} and NiO + NiAl{sub 2}O{sub 4}) issued from the decomposition of nickel hydro-aluminates at different temperatures. The first part describes experimental techniques and the nature of materials used in this study. The second part reports the study of the catalytic activity of the 2NiO+Al{sub 2}O{sub 3} catalyst during the oxidation of CO. Preliminary studies are also reported: structure and texture of nickel hydro-aluminate which is the raw material used to produce catalysts, activation of this compound to develop the catalytic activity in CO oxidation, chemisorption of CO, O{sub 2} and CO{sub 2} on the 2NiO+Al{sub 2}O{sub 3} solid, interaction of adsorbed gases at the solid surface, and kinetic study of the oxidation reaction. The third part reports the study of the catalytic activity in the oxidation reaction of CO of spinel catalysts (NiAl{sub 2}O{sub 4} and NiO+NiAl{sub 2}O{sub 4}) obtained by calcination of nickel hydro-aluminates at high temperature. The formation of the spinel phase, the chemisorption of CO, O{sub 2} and CO{sub 2} on NiAl{sub 2}O{sub 4}, and the kinetic of the oxidation reaction are herein studied.

  4. Three dimensional characterization of nickel coarsening in solid oxide cells via ex-situ ptychographic nano-tomography

    DEFF Research Database (Denmark)

    De Angelis, Salvatore; Jørgensen, Peter Stanley; Tsai, Esther Hsiao Rho

    2018-01-01

    Nickel coarsening is considered a significant cause of solid oxide cell (SOC) performance degradation. Therefore, understanding the morphological changes in the nickel-yttria stabilized zirconia (Ni-YSZ) fuel electrode is crucial for the wide spread usage of SOC technology. This paper reports...... a study of the initial 3D microstructure evolution of a SOC analyzed in the pristine state and after 3 and 8 h of annealing at 850 °C, in dry hydrogen. The analysis of the evolution of the same location of the electrode shows a substantial change of the nickel and pore network during the first 3 h...... of treatment, while only negligible changes are observed after 8 h. The nickel coarsening results in loss of connectivity in the nickel network, reduced nickel specific surface area and decreased total triple phase boundary density. For the condition of this experiment, nickel coarsening is shown...

  5. Specification and prediction of nickel mobilization using artificial intelligence methods

    Science.gov (United States)

    Gholami, Raoof; Ziaii, Mansour; Ardejani, Faramarz Doulati; Maleki, Shahoo

    2011-12-01

    Groundwater and soil pollution from pyrite oxidation, acid mine drainage generation, and release and transport of toxic metals are common environmental problems associated with the mining industry. Nickel is one toxic metal considered to be a key pollutant in some mining setting; to date, its formation mechanism has not yet been fully evaluated. The goals of this study are 1) to describe the process of nickel mobilization in waste dumps by introducing a novel conceptual model, and 2) to predict nickel concentration using two algorithms, namely the support vector machine (SVM) and the general regression neural network (GRNN). The results obtained from this study have shown that considerable amount of nickel concentration can be arrived into the water flow system during the oxidation of pyrite and subsequent Acid Drainage (AMD) generation. It was concluded that pyrite, water, and oxygen are the most important factors for nickel pollution generation while pH condition, SO4, HCO3, TDS, EC, Mg, Fe, Zn, and Cu are measured quantities playing significant role in nickel mobilization. SVM and GRNN have predicted nickel concentration with a high degree of accuracy. Hence, SVM and GRNN can be considered as appropriate tools for environmental risk assessment.

  6. Epicutaneous exposure to nickel induces nickel allergy in mice via a MyD88-dependent and interleukin-1-dependent pathway.

    Science.gov (United States)

    Vennegaard, Marie T; Dyring-Andersen, Beatrice; Skov, Lone; Nielsen, Morten M; Schmidt, Jonas D; Bzorek, Michael; Poulsen, Steen S; Thomsen, Allan R; Woetmann, Anders; Thyssen, Jacob P; Johansen, Jeanne D; Odum, Niels; Menné, Torkil; Geisler, Carsten; Bonefeld, Charlotte M

    2014-10-01

    Several attempts to establish a model in mice that reflects nickel allergy in humans have been made. Most models use intradermal injection of nickel in combination with adjuvant to induce nickel allergy. However, such models poorly reflect induction of nickel allergy following long-lasting epicutaneous exposure to nickel. To develop a mouse model reflecting nickel allergy in humans induced by epicutaneous exposure to nickel, and to investigate the mechanisms involved in such allergic responses. Mice were exposed to NiCl2 on the dorsal side of the ears. Inflammation was evaluated by the swelling and cell infiltration of the ears. T cell responses were determined as numbers of CD4+ and CD8+ T cells in the draining lymph nodes. Localization of nickel was examined by dimethylglyoxime staining. Epicutaneous exposure to nickel results in prolonged localization of nickel in the epidermis, and induces nickel allergy in mice. The allergic response to nickel following epicutaneous exposure is MyD88-dependent and interleukin (IL)-1 receptor-dependent, but independent of toll-like receptor (TLR)-4. This new model for nickel allergy that reflects epicutaneous exposure to nickel in humans shows that nickel allergy is dependent on MyD88 and IL-1 receptor signalling, but independent of TLR4. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Surface passivity largely governs the bioaccessibility of nickel-based powder particles at human exposure conditions.

    Science.gov (United States)

    Hedberg, Yolanda S; Herting, Gunilla; Latvala, Siiri; Elihn, Karine; Karlsson, Hanna L; Odnevall Wallinder, Inger

    2016-11-01

    The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, are identified and proven safe for humans and the environment. Therefore, differences in bioaccessibility in terms of released metals in synthetic biological fluids (different pH (1.5-7.4) and composition) that are relevant for different human exposure routes (inhalation, ingestion, and dermal contact) have been assessed for powder particles of an alloy containing high levels of nickel (Inconel 718, 57 wt% nickel). This powder is compared with the bioaccessibility of two nickel-containing stainless steel powders (AISI 316L, 10-12% nickel) and with powders representing their main pure alloy constituents: two nickel metal powders (100% nickel), two iron metal powders and two chromium metal powders. X-ray photoelectron spectroscopy, microscopy, light scattering, and nitrogen absorption were employed for the particle and surface oxide characterization. Atomic absorption spectroscopy was used to quantify released amounts of metals in solution. Cytotoxicity (Alamar blue assay) and DNA damage (comet assay) of the Inconel powder were assessed following exposure of the human lung cell line A549, as well as its ability to generate reactive oxygen species (DCFH-DA assay). Despite its high nickel content, the Inconel alloy powder did not release any significant amounts of metals and did not induce any toxic response. It is concluded, that this is related to the high surface passivity of the Inconel powder governed by its chromium-rich surface oxide. Read-across from the pure metal constituents is hence not recommended either for this or any other passive alloy. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Self-templated Synthesis of Nickel Silicate Hydroxide/Reduced Graphene Oxide Composite Hollow Microspheres as Highly Stable Supercapacitor Electrode Material.

    Science.gov (United States)

    Zhang, Yanhua; Zhou, Wenjie; Yu, Hong; Feng, Tong; Pu, Yong; Liu, Hongdong; Xiao, Wei; Tian, Liangliang

    2017-12-01

    Nickel silicate hydroxide/reduced graphene oxide (Ni 3 Si 2 O 5 (OH) 4 /RGO) composite hollow microspheres were one-pot hydrothermally synthesized by employing graphene oxide (GO)-wrapped SiO 2 microspheres as the template and silicon source, which were prepared through sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO 2 substrate microspheres. The composition, morphology, structure, and phase of Ni 3 Si 2 O 5 (OH) 4 /RGO microspheres as well as their electrochemical properties were carefully studied. It was found that Ni 3 Si 2 O 5 (OH) 4 /RGO microspheres featured distinct hierarchical porous morphology with hollow architecture and a large specific surface area as high as 67.6 m 2  g -1 . When utilized as a supercapacitor electrode material, Ni 3 Si 2 O 5 (OH) 4 /RGO hollow microspheres released a maximum specific capacitance of 178.9 F g -1 at the current density of 1 A g -1 , which was much higher than that of the contrastive bare Ni 3 Si 2 O 5 (OH) 4 hollow microspheres and bare RGO material developed in this work, displaying enhanced supercapacitive behavior. Impressively, the Ni 3 Si 2 O 5 (OH) 4 /RGO microsphere electrode exhibited outstanding rate capability and long-term cycling stability and durability with 97.6% retention of the initial capacitance after continuous charging/discharging for up to 5000 cycles at the current density of 6 A g -1 , which is superior or comparable to that of most of other reported nickel-based electrode materials, hence showing promising application potential in the energy storage area.

  9. Synthesis and properties of ternary mixture of nickel/cobalt/tin oxides for supercapacitors

    Science.gov (United States)

    Ferreira, C. S.; Passos, R. R.; Pocrifka, L. A.

    2014-12-01

    The present study reports the synthesis and morphological, structural and electrochemical characterization of ternary oxides mixture containing nickel, cobalt and tin. The ternary oxide is synthesized by Pechini method with subsequent deposition onto a titanium substrate in a thin-film form. XRD and EDS analysis confirm the formation of ternary film with amorphous nature. SEM analysis show that cracks on the film favor the gain of the surface area that is an interesting feature for electrochemical capacitors. The ternary film is investigated in KOH electrolyte solution using cyclic voltammetry and charge-discharge study with a specific capacitance of 328 F g-1, and a capacitance retention of 86% over 600 cycles. The values of specific power and specific energy was 345.7 W kg-1 and 18.92 Wh kg-1, respectively.

  10. Mechanisms responsible for two possible electrochemical reactions in Li1.2Ni0.13Mn0.54Co0.13O2 used for lithium ion batteries

    Science.gov (United States)

    Konishi, Hiroaki; Hirano, Tatsumi; Takamatsu, Daiko; Gunji, Akira; Feng, Xiaoliang; Furutsuki, Sho; Okumura, Takefumi; Terada, Shohei; Tamura, Kazuhisa

    2018-02-01

    Two electrochemical reactions are possible in regard to Li1.2Ni0.13Mn0.54Co0.13O2 (0.5Li2MnO3-0.5LiNi0.33Mn0.33Co0.33O2), viz, Li2MnO3-like and LiNi0.33Mn0.33Co0.33O2-like reactions. The open circuit potential (OCP) and changes in crystal structure during the charge-discharge process of Li1.2Ni0.13Mn0.54Co0.13O2 were investigated to clarify the mechanism responsible for the two reactions. Li2MnO3 and LiNi0.33Mn0.33Co0.33O2 were separately prepared for the investigation, and the OCPs and crystal structures in these cathodes were measured and then compared with those for Li1.2Ni0.13Mn0.54Co0.13O2. The results obtained using X-ray diffraction (XRD) indicated that two phases existed in Li1.2Ni0.13Mn0.54Co0.13O2. The changes in crystal structure of the two phases during the charge-discharge process were similar to those in Li2MnO3 and LiNi0.33Mn0.33Co0.33O2. This indicated that two phases, viz, Li2MnO3-like and LiNi0.33Mn0.33Co0.33O2-like, existed in Li1.2Ni0.13Mn0.54Co0.13O2. Li2MnO3-like, LiNi0.33Mn0.33Co0.33O2-like, and Li2MnO3-like phases were found to contribute mainly to electrochemical reactions in the low, middle, and high state of charge (SOC) ranges during the charge process from the results obtained using XRD and electrochemical measurements carried out on Li1.2Ni0.13Mn0.54Co0.13O2. In contrast, the Li2MnO3-like and LiNi0.33Mn0.33Co0.33O2-like phases mainly contributed to electrochemical reactions in the low and high SOC ranges during the discharge process. Furthermore, the high polarization and potential decay during the charge-discharge cycling of Li1.2Ni0.13Mn0.54Co0.13O2 were mainly attributed to the Li2MnO3-like phase.

  11. Thermochemical characteristics of La n+1Ni nO3n+1 oxides

    International Nuclear Information System (INIS)

    Bannikov, D.O.; Safronov, A.P.; Cherepanov, V.A.

    2006-01-01

    Lanthanum nickelates: La 2 NiO 4+δ , La 3 Ni 2 O 7-δ , La 4 Ni 3 O 10-δ and LaNiO 3-δ the members of Ruddlesden-Popper series La n+1 Ni n O 3n+1 were prepared using citrate route. Dissolution enthalpies of complex oxides as well as a number of subsidiary substances were measured by means of Calvet calorimeter in 1 M solution of hydrochloric acid at 25 deg. C. The dissolution scheme of complex oxides in hydrochloric acid was proposed and enthalpies of formation of the complex oxides from binary oxides were calculated considering oxygen nonstoichiometry of these substances. Enthalpies of step-by-step oxidation were evaluated. Partial enthalpy contribution of LaO layers was calculated endothermic equals to 30.9 J/mol while partial enthalpy contribution of perovskite LaNiO 3 layers was negative equals to -97.0 J/mol. Enthalpy of formation of any complex oxide of Ruddlesden-Popper series fits very well to the linear regression based on these values

  12. Nickel oxide nanoparticles exert cytotoxicity via oxidative stress and induce apoptotic response in human liver cells (HepG2).

    Science.gov (United States)

    Ahamed, Maqusood; Ali, Daoud; Alhadlaq, Hisham A; Akhtar, Mohd Javed

    2013-11-01

    Increasing use of nickel oxide nanoparticles (NiO NPs) necessitates an improved understanding of their potential impact on human health. Previously, toxic effects of NiO NPs have been investigated, mainly on airway cells. However, information on effect of NiO NPs on human liver cells is largely lacking. In this study, we investigated the reactive oxygen species (ROS) mediated cytotoxicity and induction of apoptotic response in human liver cells (HepG2) due to NiO NPs exposure. Prepared NiO NPs were crystalline and spherical shaped with an average diameter of 44 nm. NiO NPs induced cytotoxicity (cell death) and ROS generation in HepG2 cells in dose-dependent manner. Further, ROS scavenger vitamin C reduced cell death drastically caused by NiO NPs exposure indicating that oxidative stress plays an important role in NiO NPs toxicity. Micronuclei induction, chromatin condensation and DNA damage in HepG2 cells treated with NiO NPs suggest that NiO NPs induced cell death via apoptotic pathway. Quantitative real-time PCR analysis showed that following the exposure of HepG2 cells to NiO NPs, the expression level of mRNA of apoptotic genes (bax and caspase-3) were up-regulated whereas the expression level of anti-apoptotic gene bcl-2 was down-regulated. Moreover, activity of caspase-3 enzyme was also higher in NiO NPs treated cells. To the best of our knowledge this is the first report demonstrating that NiO NPs caused cytotoxicity via ROS and induced apoptosis in HepG2 cells, which is likely to be mediated through bax/bcl-2 pathway. This work warrants careful assessment of Ni NPs before their commercial and industrial applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Nanoscale investigation of the interface situation of plated nickel and thermally formed nickel silicide for silicon solar cell metallization

    Science.gov (United States)

    Mondon, A.; Wang, D.; Zuschlag, A.; Bartsch, J.; Glatthaar, M.; Glunz, S. W.

    2014-12-01

    In the context of nickel silicide formation from plated nickel layers for solar cell metallization, there are several open questions regarding contact adhesion and electrical properties. Nanoscale characterization by transmission electron microscopy has been employed to support these investigations. Interfacial oxides and silicide phases were investigated on differently prepared samples by different analytical methods associated with transmission electron microscopy analysis. Processing variations included the pre-treatment of samples before nickel plating, the used plating solution and the thermal budget for the nickel-silicon solid-state reaction. It was shown that interface oxides of only few nm thickness on both silicon and nickel silicide are present on the samples, depending on the chosen process sequence, which have been shown to play an important role in adhesion of nickel on silicide in an earlier publication. From sample pretreatment variations, conclusions about the role of an interfacial oxide in silicide formation and its influence on phase formation were drawn. Such an oxide layer hinders silicide formation except for pinhole sites. This reduces the availability of Ni and causes a silicide with low Ni content to form. Without an interfacial oxide a continuous nickel silicide of greater depth, polycrystalline modification and expected phase according to thermal budget is formed. Information about the nature of silicide growth on typical solar cell surfaces could be obtained from silicide phase and geometric observations, which were supported by FIB tomography. The theory of isotropic NiSi growth and orientation dependent NiSi2 growth was derived. By this, a very well performing low-cost metallization for silicon solar cells has been brought an important step closer to industrial introduction.

  14. Three dimensional characterization of nickel coarsening in solid oxide cells via ex-situ ptychographic nano-tomography

    Science.gov (United States)

    De Angelis, Salvatore; Jørgensen, Peter Stanley; Tsai, Esther Hsiao Rho; Holler, Mirko; Kreka, Kosova; Bowen, Jacob R.

    2018-04-01

    Nickel coarsening is considered a significant cause of solid oxide cell (SOC) performance degradation. Therefore, understanding the morphological changes in the nickel-yttria stabilized zirconia (Ni-YSZ) fuel electrode is crucial for the wide spread usage of SOC technology. This paper reports a study of the initial 3D microstructure evolution of a SOC analyzed in the pristine state and after 3 and 8 h of annealing at 850 °C, in dry hydrogen. The analysis of the evolution of the same location of the electrode shows a substantial change of the nickel and pore network during the first 3 h of treatment, while only negligible changes are observed after 8 h. The nickel coarsening results in loss of connectivity in the nickel network, reduced nickel specific surface area and decreased total triple phase boundary density. For the condition of this experiment, nickel coarsening is shown to be predominantly curvature driven, and changes in the electrode microstructure parameters are discussed in terms of local microstructural evolution.

  15. Palm H-FAME Production through Partially Hydrogenation using Nickel/Carbon Catalyst to Increase Oxidation Stability

    Directory of Open Access Journals (Sweden)

    Ramayeni Elsa

    2018-01-01

    Full Text Available One of the methods to improve the oxidation stability of palm biodiesel is through partially hydrogenation. The production using Nickel/Carbon catalyst to speed up the reaction rate. Product is called Palm H-FAME (Hydrogenated FAME. Partial hydrogenation breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester, which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation are predicted to change the oxidation stability so it does not cause deposits that can damage the injection system of diesel engine, pump system, and storage tank. Partial hydrogenation is carried out under operating conditions of 120 °C and 6 bar with 100:1, 100:3, 100:5, 100:10 % wt catalyst in the stirred batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 91.78 to 82.38 (g-I2/100 g with an increase of oxidation stability from 585 to 602 minutes.

  16. Two polymeric nickel(II) complexes with aromatic benzene-1,2,4,5-tetracarboxylate and pyridine-2,5-dicarboxylate linkers.

    Science.gov (United States)

    Atria, Ana María; Corsini, Gino; González, Lissette; Garland, Maria Teresa; Baggio, Ricardo

    2009-07-01

    (Mu-benzene-1,2,4,5-tetracarboxylato-kappa(2)O(1):O(4))bis[aquabis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)] methanol disolvate tetrahydrate, [Ni(2)(C(10)H(2)O(8))(C(5)H(14)N(2))(4)(H(2)O)(2)].2CH(4)O.4H(2)O, (I), is dinuclear, with elemental units built up around an inversion centre halving the benzene-1,2,4,5-tetracarboxylate (btc) anion, which bridges two symmetry-related Ni(II) cations. The octahedral Ni polyhedron is completed by two chelating 2,2-methylpropane-1,3-diamine (dmpda) groups and a terminal aqua ligand. Two methanol and four water solvent molecules are involved in a number of N-H...O and O-H...O hydrogen bonds which define a strongly bound two-dimensional supramolecular structure. The structure of catena-poly[[[bis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)O(5):N,O(2)-[(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)N,O(2):O(5)] octahydrate], {[Ni(2)(C(7)H(3)NO(4))(2)(C(5)H(14)N(2))(3)].8H(2)O}(n), (II), is polymeric, forming twisted chains around three independent Ni centres, two of which lie on inversion centres and the third in a general position. There are three chelating dmpda ligands (one disordered over two equally populated positions), which are each attached to a different cation, and two pyridine-2,5-dicarboxylate (pdc) anions, both chelating the Ni centre in general positions through an -O-C-C-N- loop, while acting as bridges to the remaining two centrosymmetric Ni atoms. There are, in addition, eight noncoordinated water molecules in the structure, some of which are disordered.

  17. Nickel-functionalized reduced graphene oxide with polyaniline for non-enzymatic glucose sensing

    International Nuclear Information System (INIS)

    Zhang, Bing; He, Yu; Liu, Bingqian; Tang, Dianping

    2015-01-01

    We have developed a new class of organic–inorganic hybrid nanostructures based on the use of reduced graphene oxide (rGO), polyaniline, and a nickel metal nanostructure. It was applied to efficient non-enzymatic sensing of glucose based on its electrocatalytic oxidation. Scanning electron microscopy and energy-dispersive X-Ray were employed to characterize the material. It is shown that the doped polyaniline plays an important role in the formation of the hybrid nanostructures. Improved analytical performance is found when the hybrid nanostructures were placed on a glassy carbon electrode and used for non-enzymatic sensing of glucose at a typical working potential of +450 mV and a pH value of 13. Features include a fast response (∼2 s), high sensitivity (6,050 μA mM −1 cm −2 ), a linear range from 0.1 μM to 1.0 mM, and a low detection limit (0.08 μM). The response to glucose follows a Michaelis-Menten kinetic behavior, and the K M value was determined to be 0.241 μM. Reproducibility and specificity are acceptable. Fructose and maltose do not interfere significantly. Importantly, the methodology was validated and evaluated for the analysis of 15 spiked human serum specimens, receiving in a good accordance with the results obtained by the non-enzymatic glucose sensing and the commercialized personal glucose meter. (author)

  18. Absolute determination by X-ray diffraction of a binary or ternary mixture: nickel oxide and fluoride in a nickel powder (1960); Dosage absolu par diffraction X d'un melange binaire ou ternaire: oxyde et fluorure de nickel dans une poudre de nickel (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Charpin, P; Hauptman, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The method employed is based upon the comparison between computed and measured intensities for conveniently selected X-Ray diffraction lines of each component of the powder. Care must be taken to allow for absorption, both inside each grain and in overall sample. This method has been applied to the determination of nickel oxide and fluoride in a nickel powder. (author) [French] La methode utilisee, dite 'absolue' est basee sur le calcul des intensites theoriques de raies de diffraction convenablement choisies. Elle n'est applicable que si l'absorption est negligeable a travers chaque grain constituant l'echantillon et a travers l'echantillon total. Elle a ete employee pour doser, ensemble ou separement, de l'oxyde et du fluorure de nickel dans une poudre de nickel. (auteur)

  19. Mesoporous Nickel Oxide (NiO) Nanopetals for Ultrasensitive Glucose Sensing

    Science.gov (United States)

    Mishra, Suryakant; Yogi, Priyanka; Sagdeo, P. R.; Kumar, Rajesh

    2018-01-01

    Glucose sensing properties of mesoporous well-aligned, dense nickel oxide (NiO) nanostructures (NSs) in nanopetals (NPs) shape grown hydrothermally on the FTO-coated glass substrate has been demonstrated. The structural study based investigations of NiO-NPs has been carried out by X-ray diffraction (XRD), electron and atomic force microscopies, energy dispersive X-ray (EDX), and X-ray photospectroscopy (XPS). Brunauer-Emmett-Teller (BET) measurements, employed for surface analysis, suggest NiO's suitability for surface activity based glucose sensing applications. The glucose sensor, which immobilized glucose on NiO-NPs@FTO electrode, shows detection of wide range of glucose concentrations with good linearity and high sensitivity of 3.9 μA/μM/cm2 at 0.5 V operating potential. Detection limit of as low as 1 μΜ and a fast response time of less than 1 s was observed. The glucose sensor electrode possesses good anti-interference ability, stability, repeatability & reproducibility and shows inert behavior toward ascorbic acid (AA), uric acid (UA) and dopamine acid (DA) making it a perfect non-enzymatic glucose sensor.

  20. Dynamic variation of histone H3 trimethyl Lys4 (H3K4me3) and heterochromatin protein 1 (HP1) with employment length in nickel smelting workers.

    Science.gov (United States)

    Zhao, Yanhong; Cheng, Ning; Dai, Min; Pu, Hongquan; Zheng, Tongzhang; Li, Haiyan; He, Jie; Bai, Yana

    2017-07-01

    To investigate the dynamic variation in H3K4me3 and HP1 with employment length in nickel smelting workers. Blood samples were collected from 140 nickel smelting workers and 140 age-matched office workers to test for H3K4me3, and HP1 levels. H3K4me3 was statistically significantly different (p exposure to nickel can induce oxidative damage, and increase H3K4me3 expression and inhibit HP1 expression.

  1. Epicutaneous exposure to nickel induces nickel allergy in mice via a MyD88-dependent and interleukin-1-dependent pathway

    DEFF Research Database (Denmark)

    Vennegaard, Marie T; Dyring-Andersen, Beatrice; Skov, Lone

    2014-01-01

    -lasting epicutaneous exposure to nickel. OBJECTIVE: To develop a mouse model reflecting nickel allergy in humans induced by epicutaneous exposure to nickel, and to investigate the mechanisms involved in such allergic responses. METHODS: Mice were exposed to NiCl2 on the dorsal side of the ears. Inflammation...... was evaluated by the swelling and cell infiltration of the ears. T cell responses were determined as numbers of CD4(+) and CD8(+) T cells in the draining lymph nodes. Localization of nickel was examined by dimethylglyoxime staining. RESULTS: Epicutaneous exposure to nickel results in prolonged localization...... of nickel in the epidermis, and induces nickel allergy in mice. The allergic response to nickel following epicutaneous exposure is MyD88-dependent and interleukin (IL)-1 receptor-dependent, but independent of toll-like receptor (TLR)-4. CONCLUSION: This new model for nickel allergy that reflects...

  2. Electron paramagnetic resonance response and magnetic interactions in ordered solid solutions of lithium nickel oxides

    Energy Technology Data Exchange (ETDEWEB)

    Azzoni, C.B. [Istituto Nazionale di Fisica della Materia, Dipartimento di Fisica ' Alessandro Volta' , Universita di Pavia, Pavia (Italy); Paleari, A. [Istituto Nazionale di Fisica della Materia, Dipartimento di Fisica, Universita di Milano, Milan (Italy); Massarotti, V.; Capsoni, D. [Dipartimento di Chimica-Fisica, Universita di Pavia, Pavia (Italy)

    1996-09-23

    EPR data of ordered solid solutions of lithium nickel oxides are reported as a function of the lithium content. The features of the signal and the EPR centre density are analysed by a model of dynamical trapping of holes in [(Ni{sup 2+}-O-Ni{sup 2+})-h{sup +}] complexes. The possible origin of the interactions responsible for the magnetic ordering and some features of the transport properties are also discussed. (author)

  3. Effect of calcination temperature on microstructure and electrochemical performance of lithium-rich layered oxide cathode materials

    International Nuclear Information System (INIS)

    Ma, Quanxin; Peng, Fangwei; Li, Ruhong; Yin, Shibo; Dai, Changsong

    2016-01-01

    Highlights: • A series of Li-rich layered oxide cathode materials (Li_1_._2Mn_0_._5_6Ni_0_._1_6Co_0_._0_8O_2) were successfully synthesized via a two-step synthesis method. • The effects of calcination temperature on the cathode materials were researched in detail. • A well-crystallized layered structure was obtained as the calcination temperature increased. • The samples calcined in a range of 850–900 °C exhibited excellent electrochemical performance. - Abstract: Lithium-rich layered oxide cathode materials (Li_1_._2Mn_0_._5_6Ni_0_._1_6Co_0_._0_8O_2 (LLMO)) were synthesized via a two-step synthesis method involving co-precipitation and high-temperature calcination. The effects of calcination temperature on the cathode materials were studied in detail. Structural and morphological characterizations revealed that a well-crystallized layered structure was obtained at a higher calcination temperature. Electrochemical performance evaluation revealed that a cathode material obtained at a calcination temperature of 850 °C delivered a high initial discharge capacity of 266.8 mAh g"−"1 at a 0.1 C rate and a capacity retention rate of 95.8% after 100 cycles as well as excellent rate capability. Another sample calcinated at 900 °C exhibited good cycling stability. It is concluded that the structural stability and electrochemical performance of Li-rich layered oxide cathode materials were strongly dependent on calcination temperatures. The results suggest that a calcination temperature in a range of 850–900 °C could promote electrochemical performance of this type of cathode materials.

  4. Carbon-encapsulated nickel-iron nanoparticles supported on nickel foam as a catalyst electrode for urea electrolysis

    International Nuclear Information System (INIS)

    Wu, Mao-Sung; Jao, Chi-Yu; Chuang, Farn-Yih; Chen, Fang-Yi

    2017-01-01

    Highlights: • Electrochemical process can purify the urea-rich wastewater, producing hydrogen gas. • Carbon-encapsulated nickel iron nanoparticles (CE-NiFe) are prepared by pyrolysis. • An ultra-thin layer of CE-NiFe nanoparticles is attached to the 3D Ni foam. • CE-NiFe nanoparticles escalate both the urea electrolysis and hydrogen evolution. - Abstract: A cyanide-bridged bimetallic coordination polymer, nickel hexacyanoferrate, could be pyrolyzed to form carbon-encapsulated nickel-iron (CE-NiFe) nanoparticles. The formation of nitrogen-doped spherical carbon shell with ordered mesoporous structure prevented the structural damage of catalyst cores and allowed the migration and diffusion of electrolyte into the hollow carbon spheres. An ultra-thin layer of CE-NiFe nanoparticles could be tightly attached to the three-dimensional macroporous nickel foam (NF) by electrophoretic deposition. The CE-NiFe nanoparticles could lower the onset potential and increase the current density in anodic urea electrolysis and cathodic hydrogen production as compared with bare NF. Macroporous NF substrate was very useful for the urea electrolysis and hydrogen production, which allowed for fast transport of electron, electrolyte, and gas products. The superior electrocatalytic ability of CE-NiFe/NF electrode in urea oxidation and water reduction made it favorable for versatile applications such as water treatment, hydrogen generation, and fuel cells.

  5. Bis[tris(1H-pyrazol-1-yl-κN2methane]nickel(II bis{[tris(1H-pyrazol-1-yl-κN2methane]tris(thiocyanato-κNnickelate(II} methanol disolvate

    Directory of Open Access Journals (Sweden)

    Ganna Lyubartseva

    2011-12-01

    Full Text Available Attempts to prepare the mononuclear [(tpmNiIIL3]−1 [tpm = tris(1H-pyrazol-1-ylmethane and L = thiocyanate] anion yielded the methanol-solvated salt, [(tpm2NiII][(tpmNiII(NCS3]2·2CH3OH or [Ni(C10H10N62][Ni(NCS3(C10H10N6]2·2CH3OH. The asymmetric unit consists of half a centrosymmetric bis[tris(1H-pyrazol-1-ylmethane]nickel(II cation and an octahedral nickelate(II anion bound to one tpm and three L ligands, and a methanol solvent molecule. One of the L ligands is disordered over two positions with occupancy factors of 0.650 (3 and 0.350 (3. There are O—H...S interactions between the methanol and the disordered thiocyanate anion, and a weak C—H...O hydrogen bond between the cation and the methanol O atom.

  6. Precipitation formation in recrystallized nickel-plated non-sag tungsten wire

    International Nuclear Information System (INIS)

    Lai, Z.H.

    1994-01-01

    It is well established that some metals, such as palladium and nickel, can easily penetrate into tungsten by fast diffusion via crystal defects such as grain boundaries and dislocations. As a result of the fast penetration of these so called activators the recrystallization temperature of heavily drawn non-sag tungsten wire can be lower from about 2,000 C to about 1,000 C, thus the application of the tungsten wire, serving as reinforcement material in metal matrix composites used at high temperatures, is limited. An interesting question is in which form these activators exist in the recrystallized tungsten wire. It is generally believed that W-Ni intermediate compounds could form in the recrystallized material, presumably at grain boundaries. The free energy difference between the pure tungsten fibbers and the precipitating W(Ni) solid solution was suggested as the chemical driving force which governed the recrystallization process. The presence of nickel in small particles had also been observed in recrystallized grains of nickel plated tungsten wires using scanning electron microscopy (SEM) and secondary ion mass spectroscopy. These particles were considered to be nickel rich precipitates. However, a detailed investigation of the precipitation process has not been reported. In the present work an investigation of the structure, composition and distribution of nickel rich particles precipitated in recrystallized grains of nickel plated heavily drawn non-sage tungsten wires was carried out using analytical electron microscopy (AEM)

  7. Electrochemical performance of LiNi0.5Mn1.5O4 prepared by improved solid state method as cathode in hybrid supercapacitor

    International Nuclear Information System (INIS)

    Wu Huiming; Rao, Ch. Venkateswara; Rambabu, B.

    2009-01-01

    The electrochemical performance of a hybrid asymmetric supercapacitor with activated carbon (AC) as anode and a lithium-ion intercalated compound LiNi 0.5 Mn 1.5 O 4 as cathode was studied. By using metal acetate precursors as starting materials in solid state reaction method, pure LiNi 0.5 Mn 1.5 O 4 was formed at low temperature. The role of precursors on the formation of material at low temperature and short period of time is presented. XRD confirms the cubic spinel structure (space group, Fd3m) and SEM shows the particles of size around 1 μm. The effect of the modified solid state reaction route on the structural and electrochemical properties was investigated. The fabricated hybrid supercapacitor, AC/LiNi 0.5 Mn 1.5 O 4 in a non-aqueous electrolyte 1.0 M LiPF 6 /EC-DMC exhibits a sloping voltage profile from 1.0 to 3.0 V and delivers a specific energy of ca. 56 Wh kg -1 . Moreover, it exhibits excellent cycling performance with less than 5% capacity loss over 1000 cycles.

  8. Band gap narrowing and fluorescence properties of nickel doped SnO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Arham S; Shafeeq, M Muhamed [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Z. H. College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India); Singla, M L [Central Scientific Instruments Organization (CSIO), Council of Scientific and Industrial Research (CSIR), Materials Research and Bio-Nanotechnology Division, Sector - 30/C, Chandigarh-160030 (India); Tabassum, Sartaj [Department of Chemistry, Aligarh Muslim University, Aligarh-202002 (India); Naqvi, Alim H [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Z. H. College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India); Azam, Ameer [Centre of Excellence in Materials Science (Nanomaterials), Department of Applied Physics, Z. H. College of Engineering and Technology, Aligarh Muslim University, Aligarh-202002 (India)

    2011-01-15

    Nickel-doped tin oxide nanoparticles (sub-5 nm size) with intense fluorescence emission behavior have been synthesized by sol-gel route. The structural and compositional analysis has been carried out by using XRD, TEM, FESEM and EDAX. The optical absorbance spectra indicate a band gap narrowing effect and it was found to increase with the increase in nickel concentration. The band gap narrowing at low dopant concentration (<5%) can be assigned to SnO{sub 2}-SnO{sub 2-x} alloying effect and for higher doping it may be due to the formation of defect sub-bands below the conduction band.

  9. Ultrasmall Dispersible Crystalline Nickel Oxide Nanoparticles as High-Performance Catalysts for Electrochemical Water Splitting

    Czech Academy of Sciences Publication Activity Database

    Fominykh, K.; Feckl, J. M.; Sicklinger, J.; Döblinger, M.; Böcklein, S.; Ziegler, J.; Peter, L.; Rathouský, Jiří; Scheidt, E.-W.; Bein, T.; Fattakhova-Rohlfing, D.

    2014-01-01

    Roč. 24, č. 21 (2014), s. 3123-3129 ISSN 1616-301X Institutional support: RVO:61388955 Keywords : electrocatalysis * nickel oxide * nanocrystals Subject RIV: CG - Electrochemistry Impact factor: 11.805, year: 2014

  10. Mechanisms of nickel toxicity in microorganisms

    OpenAIRE

    Macomber, Lee; Hausinger, Robert P.

    2011-01-01

    Nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. This assumption was overturned by the discovery of a nickel defense system (RcnR/RcnA) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological co...

  11. Self-Stacked Reduced Graphene Oxide Nanosheets Coated with Cobalt-Nickel Hydroxide by One-Step Electrochemical Deposition toward Flexible Electrochromic Supercapacitors.

    Science.gov (United States)

    Grote, Fabian; Yu, Zi-You; Wang, Jin-Long; Yu, Shu-Hong; Lei, Yong

    2015-09-01

    The implementation of an optical function into supercapacitors is an innovative approach to make energy storage devices smarter and to meet the requirements of smart electronics. Here, it is reported for the first time that nickel-cobalt hydroxide on reduced graphene oxide can be utilized for flexible electrochromic supercapacitors. A new and straightforward one-step electrochemical deposition process is introduced that is capable of simultaneously reducing GO and depositing amorphous Co(1-x)Ni(x)(OH)2 on the rGO. It is shown that the rGO nanosheets are homogeneously coated with metal hydroxide and are vertically stacked. No high temperature processes are used so that flexible polymer-based substrates can be coated. The synthesized self-stacked rGO-Co(1-x)Ni(x)(OH)2 nanosheet material exhibits pseudocapacitive charge storage behavior with excellent rate capability, high Columbic efficiency, and nondiffusion limited behavior. It is shown that the electrochemical behavior of the Ni(OH)2 can be modulated, by simultaneously depositing nickel and cobalt hydroxide, into broad oxidization and reduction bands. Further, the material exhibits electrochromic property and can switch between a bleached and transparent state. Literature comparison reveals that the performance characteristics of the rGO-Co(1-x)Ni(x)(OH)2 nanosheet material, in terms of gravimetric capacitance, areal capacitance, and long-term cycling stability, are among the highest reported values of supercapacitors with electrochromic property. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Cast thermally stable high temperature nickel-base alloys and casting made therefrom

    International Nuclear Information System (INIS)

    Acuncius, D.A.; Herchenroeder, R.B.; Kirchner, R.W.; Silence, W.L.

    1977-01-01

    A cast thermally stable high temperature nickel-base alloy characterized by superior oxidation resistance, sustainable hot strength and retention of ductility on aging is provided by maintaining the alloy chemistry within the composition molybdenum 13.7% to 15.5%; chromium 14.7% to 16.5%; carbon up to 0.1%, lanthanum in an effective amount to provide oxidation resistance up to 0.08%; boron up to 0.015%; manganese 0.3% to 1.0%; silicon 0.2% to 0.8%; cobalt up to 2.0%; iron up to 3.0%; tungsten up to 1.0%; copper up to 0.4%; phosphorous up to 0.02%; sulfur up to 0.015%; aluminum 0.1% to 0.5% and the balance nickel while maintaining the Nv number less than 2.31

  13. Self-propagating synthesis and aqueous durability of Nd-bearing zirconolite-rich composites using Ca(NO{sub 3}){sub 2} as the oxidant

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kuibao, E-mail: xiaobao320@163.com [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China); National Defense Key Discipline Lab of Nuclear Waste and Environmental Safety, Southwest University of Science and Technology, Mianyang 621010 (China); He, Shihong [State Nuclear Power Research Institute, Beijing 100029 (China); Yin, Dan; Peng, Le; Wu, Jingjun [State Key Laboratory Cultivation Base for Nonmetal Composite and Functional Materials, Southwest University of Science and Technology, Mianyang, Sichuan 621010 (China)

    2016-09-15

    Synroc is recognized as the second-generation waste form for safety disposal of high-level radioactive waste (HLW). In this study, zirconolite-rich Synroc waste form was readily synthesized by self-propagating high-temperature plus quick pressing (SHS/QP) using Ca(NO{sub 3}){sub 2} as the oxidant and Ti as the reductant. As the surrogate of trivalent actinides, Nd{sub 2}O{sub 3} was introduced to equally substitute the Ca and Zr sites of zirconolite with nominal stoichiometry of Ca{sub 1−x}Zr{sub 1−x}Nd{sub 2x}Ti{sub 2}O{sub 7}. The results demonstrate that zirconolite, perovskite and pyrochlore (Ca{sub 2}Ti{sub 2}O{sub 6}) coexist as the ceramic components after SHS reaction. The introduction of Nd{sub 2}O{sub 3} promotes the formation of perovskite. Nd is mostly incorporated into the Ca sites of these phases. The normalized elemental leaching rates of Ca and Nd are fairly constant in low values of 1.80 × 10{sup −2} g m{sup −2} d{sup −1} and 6.12 × 10{sup −4} g m{sup −2} d{sup −1} after 42 days. - Highlights: • Zirconolite-rich composite was synthesized by SHS using Ca(NO{sub 3}){sub 2} as the oxidant. • Nd{sub 2}O{sub 3} was successfully immobilized into the crystal structure of this waste form. • Nd was mostly incorporated into the Ca sites of zirconolite, perovskite and pyrochlore. • The normalized leaching rates of Ca and Nd are in relatively low values.

  14. Mobility enhancement in crystalline In-Ga-Zn-oxide with In-rich compositions

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsui, Kazuhiro; Matsubayashi, Daisuke; Ishihara, Noritaka; Takasu, Takako; Matsuda, Shinpei; Yamazaki, Shunpei [Semiconductor Energy Laboratory Co., Ltd., 398 Hase, Atsugi-shi 243-0036, Kanagawa (Japan)

    2015-12-28

    The electron mobility of In-Ga-Zn-oxide (IGZO) is known to be enhanced by higher In content. We theoretically investigated the mobility-enhancement mechanism by proposing an In-Ga-Zn-disorder scattering model for an In-rich crystalline IGZO (In{sub 1+x}Ga{sub 1−x}O{sub 3}(ZnO){sub m} (0 < x < 1, m > 0)) thin film. The obtained theoretical mobility was found to be in agreement with experimental Hall mobility for a crystalline In{sub 1.5}Ga{sub 0.5}O{sub 3}(ZnO) (or In{sub 3}GaZn{sub 2}O{sub 8}) thin film. The mechanism specific to In-rich crystalline IGZO thin films is based on three types of Coulomb scattering potentials that originate from effective valence differences. In this study, the In-Ga-Zn-disorder scattering model indicates that the effective valence of the In{sup 3+} ions in In-rich crystalline IGZO thin films significantly affects their electron mobility.

  15. A New Direction for Biomining: Extraction of Metals by Reductive Dissolution of Oxidized Ores

    Directory of Open Access Journals (Sweden)

    Kevin B. Hallberg

    2013-01-01

    Full Text Available Biomining, the biotechnology that uses microorganisms to extract metals from ores and concentrates, is currently used exclusively for processing reduced ores and mine wastes. Metals of economic value also occur extensively in oxidized ores, such as nickel laterites. While these are not amenable to oxidative dissolution, the ferric iron minerals they contain can, in theory, be disrupted by iron reduction, causing associated metals to be released. We have harnessed the ability of the facultatively anaerobic, acidophilic bacterium Acidithiobacillus ferroooxidans to couple the oxidation of elemental sulphur to the reduction of ferric iron in the goethite fraction of a limonitic nickel ore at 30 °C. Nickel and other metals (Co, Cr and Mn were effectively solubilised and maintained in solution due to the low pH (1.8 of the leach liquor. The results highlight the potential for the bioprocessing of oxidized, iron-rich ores using an approach that is energy-saving and environmentally-benign compared with metallurgical processes currently applied to the extraction of Ni from lateritic ores.

  16. Investigation on biomolecular interactions of nickel(II) complexes with monoanionic bidentate ligands

    Science.gov (United States)

    Jayamani, Arumugam; Sethupathi, Murugan; Ojwach, Stephen O.; Sengottuvelan, Nallathambi

    2018-01-01

    Reactions of monoanionic bidentate ligands 5-methylsalicylaldehyde (5-msal), 5-bromosalicylaldehyde (5-brsal), 5-nitrosalicylaldehyde (5-nsal) and 2-hydroxy-1-naphthaldehyde (2-hnap) with nickel perchlorate hexahydrate produced nickel(II) complexes 1-4, respectively. Single crystal X-ray analyses of complexes 1 and 2 confirmed bidentate mode of the ligands with O˄O coordination to give square planar geometry around nickel atoms. Complexes 1-4 showed one quasi-reversible redox peak at cathodic region (-0.67 to -0.80 V) and one redox peak at anodic region (+1.08 to +1.44 V) assignable to the Ni(II)/Ni(I) and Ni(II)/Ni(III) redox couples, respectively. The complexes exhibited good bovine serum albumin (BSA) binding abilities with a maximum binding constant of 1.96 × 105 M-1. The binding of complexes with calf thymus DNA (ctDNA) showed that the binding affinity is consistent with an increase in steric bulk of the ligands. The nuclease activity of the complexes showed efficient oxidative cleavage in the presence of hydrogen peroxide as an oxidizing agent. The complexes showed higher zone of inhibition when screened for antimicrobial activity against bacteria and human pathogenic fungi.

  17. Nickel exposure is associated with the prevalence of type 2 diabetes in Chinese adults.

    Science.gov (United States)

    Liu, Gang; Sun, Liang; Pan, An; Zhu, Mingjiang; Li, Zi; ZhenzhenWang, Zhenzhen; Liu, Xin; Ye, Xingwang; Li, Huaixing; Zheng, He; Ong, Choon Nam; Yin, Huiyong; Lin, Xu; Chen, Yan

    2015-02-01

    Nickel exposure can induce hyperglycaemia in rodents, but little is known about its association with abnormal glucose metabolism in humans. We aimed to investigate the association of nickel exposure with the prevalence of type 2 diabetes in Chinese adults. A total of 2115 non-institutionalized men and women aged 55 to 76 years from Beijing and Shanghai were included, and urinary nickel concentration was assessed by inductively coupled plasma mass spectroscopy. The prevalence of type 2 diabetes was compared across urinary nickel quartiles. Fasting plasma glucose, insulin, lipids, C-reactive protein and glycated haemoglobin A1c, as well as urinary albumin and creatinine were measured. The median concentration of urinary nickel was 3.63 mg/l (interquartile range: 2.29–5.89 mg/l), and the prevalence of diabetes was 35.3% (747 cases/2115 persons). Elevated levels of urinary nickel were associated with higher fasting glucose, glycated haemoglobin A1c, insulin and homeostatic model assessment of insulin resistance (all Pnickel quartiles were 1.27 (0.97–1.67), 1.78 (1.36–2.32) and 1.68 (1.29–2.20), respectively (referencing to 1.00), after multivariate adjustment including lifestyle factors, body mass index and family history of diabetes (P for trend nickel concentration is associated with elevated prevalence of type 2 diabetes in humans.

  18. Electrochemical performance of Li-rich oxide composite material coated with Li0.75La0.42TiO3 ionic conductor

    International Nuclear Information System (INIS)

    Yang, Chun-Chen; Liao, Pin-Ci; Wu, Yi-Shiuan; Lue, Shingjiang Jessie

    2017-01-01

    Graphical abstract: Schematic diagram for Li-rich oxide (Li 1.2 Ni 0.2 Mn 0.60 O 2 ) coated with Li 0.75 La 0.42 TiO 3 (LLTO) solid ionic conductor. - Highlights: • Li 1.2 Ni 0.2 Mn 0.60 O 2 /C composite material was prepared by one-pot solid-state method. • 1D a-MnO 2 nanowires and microsphere hollow b-Ni(OH) 2 were prepared by a hydrothermal method. • 1 wt.%LLTO-coated composite showed the best performance among samples. • LLTO layer not only improves the ionic transport of Li-rich oxide material, but also prevent Li-rich material corrosion. - Abstract: Li-rich (spray-dried (SP)-Li 1.2 Ni 0.2 Mn 0.60 O 2 ) composite materials were prepared via two-step ball-mill and spray dry methods by using LiOH, α-MnO 2 , β-Ni(OH) 2 raw materials. Two raw materials of α-MnO 2 nanowires and microsphere β-Ni(OH) 2 were synthesized by a hydrothermal process. In addition, Li 0.75 La 0.42 TiO3 (LLTO) fast ionic conductor was coated on SP-Li 1.2 Ni 0.2 Mn 0.60 O 2 composite via a sol–gel method. The properties of the LLTO-coated SP-Li 1.2 Ni 0.2 Mn 0.60 O 2 composites were determined by X-ray diffraction, scanning electron microscopy, micro-Raman, XPS, and the AC impedance method. The discharge capacities of 1 wt.%-LLTO-coated SP-Li 1.2 Ni 0.2 Mn 0.60 O 2 composites were 256, 250, 231, 200, 158, and 114 mAh g −1 at rates of 0.1, 0.2, 0.5, 1, 3, and 5C, respectively, in the voltage range 2.0–4.8 V. The 1 wt.%-LLTO-coated Li-rich oxide composite showed the discharge capacities of up to 256 mAh g −1 in the first cycle at 0.1C. After 30 cycles, the discharge capacity of 244 mAh g −1 was obtained, which showed the capacity retention of 95.4%.

  19. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-02-20

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  20. Nickel hydroxide positive electrode for alkaline rechargeable battery

    Science.gov (United States)

    Young, Kwo; Wang, Lixin; Mays, William; Reichman, Benjamin; Chao-Ian, Hu; Wong, Diana; Nei, Jean

    2018-04-03

    Certain nickel hydroxide active cathode materials for use in alkaline rechargeable batteries are capable of transferring >1.3 electrons per Ni atom under reversible electrochemical conditions. The specific capacity of the nickel hydroxide active materials is for example .gtoreq.325 mAh/g. The cathode active materials exhibit an additional discharge plateau near 0.8 V vs. a metal hydride (MH) anode. Ni in an oxidation state of less than 2, such as Ni.sup.1+, is able to participate in electrochemical reactions when using the present cathode active materials. It is possible that up to 2.3 electrons, up to 2.5 electrons or more may be transferred per Ni atom under electrochemical conditions.

  1. Lithium recycling and cathode material regeneration from acid leach liquor of spent lithium-ion battery via facile co-extraction and co-precipitation processes.

    Science.gov (United States)

    Yang, Yue; Xu, Shengming; He, Yinghe

    2017-06-01

    A novel process for extracting transition metals, recovering lithium and regenerating cathode materials based on facile co-extraction and co-precipitation processes has been developed. 100% manganese, 99% cobalt and 85% nickel are co-extracted and separated from lithium by D2EHPA in kerosene. Then, Li is recovered from the raffinate as Li 2 CO 3 with the purity of 99.2% by precipitation method. Finally, organic load phase is stripped with 0.5M H 2 SO 4 , and the cathode material LiNi 1/3 Co 1/3 Mn 1/3 O 2 is directly regenerated from stripping liquor without separating metal individually by co-precipitation method. The regenerative cathode material LiNi 1/3 Co 1/3 Mn 1/3 O 2 is miro spherical morphology without any impurities, which can meet with LiNi 1/3 Co 1/3 Mn 1/3 O 2 production standard of China and exhibits good electrochemical performance. Moreover, a waste battery management model is introduced to guarantee the material supply for spent battery recycling. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Sponge-like Si-SiO2 nanocomposite—Morphology studies of spinodally decomposed silicon-rich oxide

    Science.gov (United States)

    Friedrich, D.; Schmidt, B.; Heinig, K. H.; Liedke, B.; Mücklich, A.; Hübner, R.; Wolf, D.; Kölling, S.; Mikolajick, T.

    2013-09-01

    Sponge-like Si nanostructures embedded in SiO2 were fabricated by spinodal decomposition of sputter-deposited silicon-rich oxide with a stoichiometry close to that of silicon monoxide. After thermal treatment a mean feature size of about 3 nm was found in the phase-separated structure. The structure of the Si-SiO2 nanocomposite was investigated by energy-filtered transmission electron microscopy (EFTEM), EFTEM tomography, and atom probe tomography, which revealed a percolated Si morphology. It was shown that the percolation of the Si network in 3D can also be proven on the basis of 2D EFTEM images by comparison with 3D kinetic Monte Carlo simulations.

  3. Sponge-like Si-SiO2 nanocomposite—Morphology studies of spinodally decomposed silicon-rich oxide

    International Nuclear Information System (INIS)

    Friedrich, D.; Schmidt, B.; Heinig, K. H.; Liedke, B.; Mücklich, A.; Hübner, R.; Wolf, D.; Kölling, S.; Mikolajick, T.

    2013-01-01

    Sponge-like Si nanostructures embedded in SiO 2 were fabricated by spinodal decomposition of sputter-deposited silicon-rich oxide with a stoichiometry close to that of silicon monoxide. After thermal treatment a mean feature size of about 3 nm was found in the phase-separated structure. The structure of the Si-SiO 2 nanocomposite was investigated by energy-filtered transmission electron microscopy (EFTEM), EFTEM tomography, and atom probe tomography, which revealed a percolated Si morphology. It was shown that the percolation of the Si network in 3D can also be proven on the basis of 2D EFTEM images by comparison with 3D kinetic Monte Carlo simulations

  4. Effect of calcination temperature on microstructure and electrochemical performance of lithium-rich layered oxide cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Quanxin; Peng, Fangwei; Li, Ruhong; Yin, Shibo; Dai, Changsong, E-mail: changsd@hit.edu.cn

    2016-11-15

    Highlights: • A series of Li-rich layered oxide cathode materials (Li{sub 1.2}Mn{sub 0.56}Ni{sub 0.16}Co{sub 0.08}O{sub 2}) were successfully synthesized via a two-step synthesis method. • The effects of calcination temperature on the cathode materials were researched in detail. • A well-crystallized layered structure was obtained as the calcination temperature increased. • The samples calcined in a range of 850–900 °C exhibited excellent electrochemical performance. - Abstract: Lithium-rich layered oxide cathode materials (Li{sub 1.2}Mn{sub 0.56}Ni{sub 0.16}Co{sub 0.08}O{sub 2} (LLMO)) were synthesized via a two-step synthesis method involving co-precipitation and high-temperature calcination. The effects of calcination temperature on the cathode materials were studied in detail. Structural and morphological characterizations revealed that a well-crystallized layered structure was obtained at a higher calcination temperature. Electrochemical performance evaluation revealed that a cathode material obtained at a calcination temperature of 850 °C delivered a high initial discharge capacity of 266.8 mAh g{sup −1} at a 0.1 C rate and a capacity retention rate of 95.8% after 100 cycles as well as excellent rate capability. Another sample calcinated at 900 °C exhibited good cycling stability. It is concluded that the structural stability and electrochemical performance of Li-rich layered oxide cathode materials were strongly dependent on calcination temperatures. The results suggest that a calcination temperature in a range of 850–900 °C could promote electrochemical performance of this type of cathode materials.

  5. Nickel-regulated heart rate variability: The roles of oxidative stress and inflammation

    International Nuclear Information System (INIS)

    Chuang, Hsiao-Chi; Hsueh, Tzu-Wei; Chang, Chuen-Chau; Hwang, Jing-Shiang; Chuang, Kai-Jen; Yan, Yuan-Horng; Cheng, Tsun-Jen

    2013-01-01

    Heart rate variability (HRV) has been reported to be a putative marker of cardiac autonomic imbalance caused by exposure to ambient particulate matter (PM). Our objective in this study was to determine the effects on HRV from exposure to nickel, an important chemical component of ambient PM that results in oxidative stress and inflammation. HRV data were collected for 72 h before lung exposure (baseline) and 72 h after intratracheal exposure (response) to nickel sulphate (NiSO 4 ; 526 μg) in Wistar Kyoto (WKY) and spontaneously hypertensive (SH) rats. The antioxidant N-acetyl-L-cysteine (NAC) and the anti-inflammatory celecoxib were intraperitoneally injected to examine post-exposure oxidative and inflammatory responses. Self-controlled experiments examined the effects of NiSO 4 exposure on average normal-to-normal intervals (ANN), natural logarithm-transformed standard deviation of the normal-to-normal intervals (LnSDNN) and root mean square of successive differences of adjacent normal-to-normal intervals (LnRMSSD); the resulting data were sequentially analysed using the generalised estimating equation model. HRV effects on NiSO 4 -exposed SH rats were greater than those on NiSO 4 -exposed WKY rats. After adjusted the HRV responses in the WKY rats as control, ANN and LnRMSSD were found to be quadratically increased over 72 h after exposure to NiSO 4 . Both NAC and celecoxib mitigated the NiSO 4 -induced alterations in HRV during the exposure period. The results suggest that concurrent Ni-induced oxidative stress and inflammatory responses play important roles in regulating HRV. These findings help bridge the gap between epidemiological and clinical studies on the plausible mechanisms of the cardiovascular consequences induced by chemical components in ambient PM. -- Highlights: ► To determine the effects on HRV from exposure to nickel. ► ANN and LnRMSSD were found to be quadratically increased after exposure to Ni. ► NAC and celecoxib mitigated the Ni

  6. Nickel-regulated heart rate variability: The roles of oxidative stress and inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Hsiao-Chi, E-mail: r92841005@ntu.edu.tw [School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Hsueh, Tzu-Wei, E-mail: r95841015@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, Department of Public Health, National Taiwan University, Taipei, Taiwan (China); Chang, Chuen-Chau, E-mail: nekota@tmu.edu.tw [Department of Anaesthesiology, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan (China); Hwang, Jing-Shiang, E-mail: jshwang@stat.sinica.edu.tw [Institute of Statistical Science, Academia Sinica, Taipei, Taiwan (China); Chuang, Kai-Jen, E-mail: kjc@tmu.edu.tw [Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Yan, Yuan-Horng, E-mail: d97841006@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, Department of Public Health, National Taiwan University, Taipei, Taiwan (China); Department of Medical Research, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi City, Taiwan (China); Cheng, Tsun-Jen, E-mail: tcheng@ntu.edu.tw [Institute of Occupational Medicine and Industrial Hygiene, Department of Public Health, National Taiwan University, Taipei, Taiwan (China); Department of Public Health, College of Public Health, National Taiwan University, Taipei, Taiwan (China)

    2013-01-15

    Heart rate variability (HRV) has been reported to be a putative marker of cardiac autonomic imbalance caused by exposure to ambient particulate matter (PM). Our objective in this study was to determine the effects on HRV from exposure to nickel, an important chemical component of ambient PM that results in oxidative stress and inflammation. HRV data were collected for 72 h before lung exposure (baseline) and 72 h after intratracheal exposure (response) to nickel sulphate (NiSO{sub 4}; 526 μg) in Wistar Kyoto (WKY) and spontaneously hypertensive (SH) rats. The antioxidant N-acetyl-L-cysteine (NAC) and the anti-inflammatory celecoxib were intraperitoneally injected to examine post-exposure oxidative and inflammatory responses. Self-controlled experiments examined the effects of NiSO{sub 4} exposure on average normal-to-normal intervals (ANN), natural logarithm-transformed standard deviation of the normal-to-normal intervals (LnSDNN) and root mean square of successive differences of adjacent normal-to-normal intervals (LnRMSSD); the resulting data were sequentially analysed using the generalised estimating equation model. HRV effects on NiSO{sub 4}-exposed SH rats were greater than those on NiSO{sub 4}-exposed WKY rats. After adjusted the HRV responses in the WKY rats as control, ANN and LnRMSSD were found to be quadratically increased over 72 h after exposure to NiSO{sub 4}. Both NAC and celecoxib mitigated the NiSO{sub 4}-induced alterations in HRV during the exposure period. The results suggest that concurrent Ni-induced oxidative stress and inflammatory responses play important roles in regulating HRV. These findings help bridge the gap between epidemiological and clinical studies on the plausible mechanisms of the cardiovascular consequences induced by chemical components in ambient PM. -- Highlights: ► To determine the effects on HRV from exposure to nickel. ► ANN and LnRMSSD were found to be quadratically increased after exposure to Ni. ► NAC and

  7. Effect of CTAB concentration on synthesis of nickel doped manganese oxide nanoparticles

    Science.gov (United States)

    Shobana, R.; Saravanakumar, B.; Ravi, G.; Yuvakkumar, R.

    2018-05-01

    In this work the effect of concentration of cetyltrimethylammonium bromide (CTAB) in the synthesis of Nickel doped Manganese oxide (Ni-MnO2) nanoparticles have been carried out by adopting the sol-gel process. The synthesized products were characterized by XRD, Infra- Red (FTIR) and SEM analysis. The XRD confirms the formation of Ni-MnO2 nanoparticles illustrate peak at 31.4° with lattice plane (-231). The IR spectra correspond to the peak at 592 and 846 cm-1 attributed to the characteristics peak for Ni-MnO2 nanoparticles. The SEM images for all three Ni-MnO2 nanoparticles for different concentration of CTAB allows us to assess the formation route of nano tentacles from 10 mM, 30 mM and 50 mM. The configured nano tentacles of Ni-MnO2 nanoparticles presumably leads to more significantly change its properties, particularly in its electrochemical properties show the ways to be suitable candidates for supercapacitor, battery, photo catalytic and fuel cell applications.

  8. Salinity-dependent nickel accumulation and oxidative stress responses in the euryhaline killifish (Fundulus heteroclitus).

    Science.gov (United States)

    Blewett, Tamzin A; Wood, Chris M

    2015-02-01

    The mechanisms of nickel (Ni) toxicity in marine fish remain unclear, although evidence from freshwater (FW) fish suggests that Ni can act as a pro-oxidant. This study investigated the oxidative stress effects of Ni on the euryhaline killifish (Fundulus heteroclitus) as a function of salinity. Killifish were exposed to sublethal levels (5, 10, and 20 mg L(-1)) of waterborne Ni for 96 h in FW (0 ppt) and 100 % saltwater (SW) (35 ppt). In general, SW was protective against both Ni accumulation and indicators of oxidative stress [protein carbonyl formation and catalase (CAT) activity]. This effect was most pronounced at the highest Ni exposure level. For example, FW intestine showed increased Ni accumulation relative to SW intestine at 20 mg Ni L(-1), and this was accompanied by significantly greater protein carbonylation and CAT activity in this tissue. There were exceptions, however, in that although liver of FW killifish at the highest exposure concentration showed greater Ni accumulation relative to SW liver, levels of CAT activity were greatly decreased. This may relate to tissue- and salinity-specific differences in oxidative stress responses. The results of the present study suggest (1) that there was Ni-induced oxidative stress in killifish, (2) that the effects of salinity depend on differences in the physiology of the fish in FW versus SW, and (3) that increased levels of cations (sodium, calcium, potassium, and magnesium) and anions (SO4 and Cl) in SW are likely protective against Ni accumulation in tissues exposed to the aquatic environment.

  9. LiNi1/3Co1/3Mn1/3O2 nanoplates with {010} active planes exposing prepared in polyol medium as a high-performance cathode for Li-ion battery.

    Science.gov (United States)

    Li, Jili; Yao, Ruimin; Cao, Chuanbao

    2014-04-09

    As we know, Li(+)-ion transport in layered LiNi1/3Co1/3Mn1/3O2 (NCM) is through two-dimensional channels parallel to the Li(+)-ion layers that are indexed as {010} active planes. In this paper, NCM nanoplates with exposed {010} active facets are synthesized in a polyol medium (ethylene glycol) and characterized by XRD, XPS, SEM, and HR-TEM. In addition, the effects of reaction conditions on the morphologies, structures and electrochemical performances are also evaluated. The results show that more {010} facets can be exposed with the thickness of NCM nanoplates increasing which can lead to more channels for Li(+)-ion migration. However, when the annealing temperatures exceed 900 °C, many new crystal planes grow along the thickness direction covering the {010} facets. In all of the NCM nanoplates obtained at different conditions, the NCM nanoplates calcined at 850 °C for 12 h (NCM-850-12H) display a high initial discharge capacity of 207.6 mAh g(-1) at 0.1 C (1 C = 200 mA g(-1)) between 2.5 and 4.5 V higher than most of NCM materials as cathodes for lithium ion batteries. The discharge capacities of NCM-850-12H are 169.8, 160.5, and 149.3 mAh g(-1) at 2, 5, and 7 C, respectively, illustrating the excellent rate capability. The superior electrochemical performance of NCM-850-12H cathode can be attributed to more {010} active planes exposure.

  10. High temperature oxidation behaviour of nanostructured cermet coatings in a mixed CO2 - O2 environment

    Science.gov (United States)

    Farrokhzad, M. A.; Khan, T. I.

    2014-06-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (α-Al2O3 and TiO2) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500°C, 600°C and 700°C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15% CO2, 10% O2 and 75% N2. This research investigates the effects of CO2 and O2 partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO2 at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO2 in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO2 acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO2 particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Ni-Ti compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings.

  11. Material properties of oxide dispersion strengthened (ODS) ferritic steels for core materials of FBR. Tensile properties of sodium exposed and nickel diffused materials

    International Nuclear Information System (INIS)

    Kato, Shoichi; Yoshida, Eiichi

    2002-12-01

    An oxide dispersion strengthened (ODS) ferritic steel is candidate for a long-life core materials of future FBR, because of good swelling resistance and high creep strength. In this study, tensile tests were carried out the long-term extrapolation of sodium environmental effects on the mechanical properties of ODS steels. The tested heats of materials are M93, M11 and F95. The specimens were pre-exposed to sodium for 1,000 and 3,000 hours under non-stress conditions. The pre-exposure to sodium was conducted using a sodium test loop constituted by austenitic steels. For the conditions of sodium exposure test, the sodium temperature was 650 and 700degC, the oxygen concentration in sodium was about 1 ppm and sodium flow rate on the surface of specimen was less than 1x10 -4 m/seconds (nearly static). Further the specimen with the nickel diffused was prepared, which is simulate to nickel diffusing through sodium from the surface of structural stainless steels. The main results obtained were as follows; (1) The tensile strength and the fracture elongation after sodium exposure (maximum 3,000 hours) were same as that of as-received materials. If was considered that the sodium environmental effect is negligible under the condition of this study. (2) Tensile properties of nickel diffused specimens were slightly lower than that of the as-received specimens, but it remains equal to that of thermal aging specimens. (3) The change in microstructure such as a degraded layer was observed on the surface of nickel diffused specimen. In the region of the degraded layer, phase transformations from the α-phase to the γ-phase were recognized. But, the microscopic oxide particles were observed same as that of α-phase base metal. (author)

  12. Evolution of the nickel/zirconia interface

    International Nuclear Information System (INIS)

    Shinde, S.L.; Olson, D.A.; De Jonghe, L.C.; Miller, R.A.

    1986-01-01

    The changes taking place at the nickel zirconia interface during oxidation in air at 900 0 C were studied using analytical electron microscopy (AEM). The nickel oxide layer growing at the interface and the stabilizers used in zirconia interact, giving different interface morphologies

  13. Microwave-enhanced electrochemical cycling performance of the LiNi0.2Mn1.8O4 spinel cathode material at elevated temperature

    CSIR Research Space (South Africa)

    Raju, Kumar

    2016-04-01

    Full Text Available microwave-assisted solid-state reaction has been used to dope LMO with a very low amount of nickel (i.e., LiNi(sub0.2)Mn(sub1.8)O(sub4), herein abbreviated as LMNO) for lithium-ion batteries from Mn(sub3)O(sub4) which is prepared from electrolytic manganese...

  14. Electrochemical performance of all-solid-state lithium secondary batteries with Li-Ni-Co-Mn oxide positive electrodes

    International Nuclear Information System (INIS)

    Kitaura, Hirokazu; Hayashi, Akitoshi; Tadanaga, Kiyoharu; Tatsumisago, Masahiro

    2010-01-01

    LiNi 1/3 Co 1/3 Mn 1/3 O 2 was applied as a promising material to the all-solid-state lithium cells using the 80Li 2 S.19P 2 S 5 .1P 2 O 5 (mol%) solid electrolyte. The cell showed the first discharge capacity of 115 mAh g -1 at the current density of 0.064 mA cm -2 and retained the reversible capacity of 110 mAh g -1 after 10 cycles. The interfacial resistance was observed in the impedance spectrum of the all-solid-state cell charged to 4.4 V (vs. Li) and the transition metal elements were detected on the solid electrolyte in the vicinity of LiNi 1/3 Co 1/3 Mn 1/3 O 2 by the TEM observations with EDX analyses. The electrochemical performance was improved by the coating of LiNi 1/3 Co 1/3 Mn 1/3 O 2 particles with Li 4 Ti 5 O 12 film. The interfacial resistance was decreased and the discharge capacity was increased from 63 to 83 mAh g -1 at 1.3 mA cm -2 by the coating. The electrochemical performance of LiNi 1/3 Co 1/3 Mn 1/3 O 2 was compared with that of LiCoO 2 , LiMn 2 O 4 and LiNiO 2 in the all-solid-state cells. The rate capability of LiNi 1/3 Co 1/3 Mn 1/3 O 2 was lower than that of LiCoO 2 . However, the reversible capacity of LiNi 1/3 Co 1/3 Mn 1/3 O 2 at 0.064 mA cm -2 was larger than that of LiCoO 2 , LiMn 2 O 4 and LiNiO 2 .

  15. Jet-stirred reactor oxidation of alkane-rich FACE gasoline fuels

    KAUST Repository

    Chen, Bingjie

    2016-06-23

    Understanding species evolution upon gasoline fuel oxidation can aid in mitigating harmful emissions and improving combustion efficiency. Experimentally measured speciation profiles are also important targets for surrogate fuel kinetic models. This work presents the low- and high-temperature oxidation of two alkane-rich FACE gasolines (A and C, Fuels for Advanced Combustion Engines) in a jet-stirred reactor at 10. bar and equivalence ratios from 0.5 to 2 by probe sampling combined with gas chromatography and Fourier Transformed Infrared Spectrometry analysis. Detailed speciation profiles as a function of temperature are presented and compared to understand the combustion chemistry of these two real fuels. Simulations were conducted using three surrogates (i.e., FGA2, FGC2, and FRF 84), which have similar physical and chemical properties as the two gasolines. The experimental results reveal that the reactivity and major product distributions of these two alkane-rich FACE fuels are very similar, indicating that they have similar global reactivity despite their different compositions. The simulation results using all the surrogates capture the two-stage oxidation behavior of the two FACE gasolines, but the extent of low temperature reactivity is over-predicted. The simulations were analyzed, with a focus on the n-heptane and n-butane sub-mechanisms, to help direct the future model development and surrogate fuel formulation strategies.

  16. Jet-stirred reactor oxidation of alkane-rich FACE gasoline fuels

    KAUST Repository

    Chen, Bingjie; Togbé , Casimir; Wang, Zhandong; Dagaut, Philippe; Sarathy, Mani

    2016-01-01

    Understanding species evolution upon gasoline fuel oxidation can aid in mitigating harmful emissions and improving combustion efficiency. Experimentally measured speciation profiles are also important targets for surrogate fuel kinetic models. This work presents the low- and high-temperature oxidation of two alkane-rich FACE gasolines (A and C, Fuels for Advanced Combustion Engines) in a jet-stirred reactor at 10. bar and equivalence ratios from 0.5 to 2 by probe sampling combined with gas chromatography and Fourier Transformed Infrared Spectrometry analysis. Detailed speciation profiles as a function of temperature are presented and compared to understand the combustion chemistry of these two real fuels. Simulations were conducted using three surrogates (i.e., FGA2, FGC2, and FRF 84), which have similar physical and chemical properties as the two gasolines. The experimental results reveal that the reactivity and major product distributions of these two alkane-rich FACE fuels are very similar, indicating that they have similar global reactivity despite their different compositions. The simulation results using all the surrogates capture the two-stage oxidation behavior of the two FACE gasolines, but the extent of low temperature reactivity is over-predicted. The simulations were analyzed, with a focus on the n-heptane and n-butane sub-mechanisms, to help direct the future model development and surrogate fuel formulation strategies.

  17. Two pathways for electrocatalytic oxidation of hydrogen by a nickel bis(diphosphine) complex with pendant amines in the second coordination sphere.

    Science.gov (United States)

    Yang, Jenny Y; Smith, Stuart E; Liu, Tianbiao; Dougherty, William G; Hoffert, Wesley A; Kassel, W Scott; Rakowski DuBois, M; DuBois, Daniel L; Bullock, R Morris

    2013-07-03

    A nickel bis(diphosphine) complex containing pendant amines in the second coordination sphere, [Ni(P(Cy)2N(t-Bu)2)2](BF4)2 (P(Cy)2N(t-Bu)2 = 1,5-di(tert-butyl)-3,7-dicyclohexyl-1,5-diaza-3,7-diphosphacyclooctane), is an electrocatalyst for hydrogen oxidation. The addition of hydrogen to the Ni(II) complex gives three isomers of the doubly protonated Ni(0) complex [Ni(P(Cy)2N(t-Bu)2H)2](BF4)2. Using the pKa values and Ni(II/I) and Ni(I/0) redox potentials in a thermochemical cycle, the free energy of hydrogen addition to [Ni(P(Cy)2N(t-Bu)2)2](2+) was determined to be -7.9 kcal mol(-1). The catalytic rate observed in dry acetonitrile for the oxidation of H2 depends on base size, with larger bases (NEt3, t-BuNH2) resulting in much slower catalysis than n-BuNH2. The addition of water accelerates the rate of catalysis by facilitating deprotonation of the hydrogen addition product before oxidation, especially for the larger bases NEt3 and t-BuNH2. This catalytic pathway, where deprotonation occurs prior to oxidation, leads to an overpotential that is 0.38 V lower compared to the pathway where oxidation precedes proton movement. Under the optimal conditions of 1.0 atm H2 using n-BuNH2 as a base and with added water, a turnover frequency of 58 s(-1) is observed at 23 °C.

  18. Oxygen-Rich Lithium Oxide Phases Formed at High Pressure for Potential Lithium-Air Battery Electrode.

    Science.gov (United States)

    Yang, Wenge; Kim, Duck Young; Yang, Liuxiang; Li, Nana; Tang, Lingyun; Amine, Khalil; Mao, Ho-Kwang

    2017-09-01

    The lithium-air battery has great potential of achieving specific energy density comparable to that of gasoline. Several lithium oxide phases involved in the charge-discharge process greatly affect the overall performance of lithium-air batteries. One of the key issues is linked to the environmental oxygen-rich conditions during battery cycling. Here, the theoretical prediction and experimental confirmation of new stable oxygen-rich lithium oxides under high pressure conditions are reported. Three new high pressure oxide phases that form at high temperature and pressure are identified: Li 2 O 3 , LiO 2 , and LiO 4 . The LiO 2 and LiO 4 consist of a lithium layer sandwiched by an oxygen ring structure inherited from high pressure ε-O 8 phase, while Li 2 O 3 inherits the local arrangements from ambient LiO 2 and Li 2 O 2 phases. These novel lithium oxides beyond the ambient Li 2 O, Li 2 O 2 , and LiO 2 phases show great potential in improving battery design and performance in large battery applications under extreme conditions.

  19. Reaction kinetics of oxygen on single-phase alloys, oxidation of nickel and niobium alloys

    International Nuclear Information System (INIS)

    Lalauze, Rene

    1973-01-01

    This research thesis first addresses the reaction kinetics of oxygen on alloys. It presents some generalities on heterogeneous reactions (conventional theory, theory of jumps), discusses the core reaction (with the influence of pressure), discusses the influence of metal self-diffusion on metal oxidation kinetics (equilibrium conditions at the interface, hybrid diffusion regime), reports the application of the hybrid diffusion model to the study of selective oxidation of alloys (Wagner model, hybrid diffusion model) and the study of the oxidation kinetics of an alloy forming a solid solution of two oxides. The second part reports the investigation of the oxidation of single phase nickel and niobium alloys (phase α, β and γ)

  20. Carbon deposition on nickel ferrites and nickel-magnetite surfaces

    International Nuclear Information System (INIS)

    Allen, G.C.; Jutson, J.A.

    1988-06-01

    Carbon deposition on Commercial Advanced Gas-Cooled Reactor (CAGR) fuel cladding and heat exchanger surfaces lowers heat transfer efficiency and increases fuel pin temperatures. Several types of deposit have been identified including both thin dense layers and also low density columnar deposits with filamentary or convoluted laminar structure. The low-density types are often associated with particles containing iron, nickel or manganese. To identify the role of nickel in the deposition process surfaces composed of nickel-iron spinels or metallic nickel/magnetite mixtures have been exposed to γ radiation in a gas environment simulating that in the reactor. Examination of these surfaces by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) have shown that while metallic nickel (Ni(O)) catalyses the formation of filamentary low density carbon deposits, the presence of divalent nickel (Ni(II)) sites in spinel type oxides is associated only with dense deposits. (author)

  1. Microwave assisted synthesis of MnO2 on nickel foam-graphene for electrochemical capacitor

    International Nuclear Information System (INIS)

    Bello, A.; Fashedemi, O.O.; Fabiane, M.; Lekitima, J.N.; Ozoemena, K.I.; Manyala, N.

    2013-01-01

    Highlights: •Three-dimensional synthesis of graphene using CVD. •Hydrothermal deposition (microwave irradiation) of MnO 2 on graphene. •Morphologies of the composite reveals flower-like nanostructures of MnO 2 on graphene. •Composite exhibit excellent electrochemical performance. -- Abstract: A green chemistry approach (hydrothermal microwave irradiation) has been used to deposit manganese oxide on nickel foam-graphene. The 3D graphene was synthesized using nickel foam template by chemical vapor deposition (CVD) technique. Raman spectroscopy, X-ray diffraction (XRD), scanning electron and transmission electron microscopies (SEM and TEM) have been used to characterize structure and surface morphology of the composite, respectively. The Raman spectroscopy measurements on the samples reveal that 3D graphene consists of mostly few layers with low defect density. The composite was tested in a three electrode configuration for electrochemical capacitor, and exhibited a specific capacitance of 305 F g −1 at a current density of 1 A g −1 and showed excellent cycling stability. The obtained results demonstrate that microwave irradiation technique could be a promising approach to synthesis graphene based functional materials for electrochemical applications

  2. Structural evolution of bias sputtered LiNi0.5Mn1.5O4 thin film cathodes for lithium ion batteries

    International Nuclear Information System (INIS)

    Su, Shih-Hsuan; Chiu, Kuo-Feng; Leu, Hoang-Jyh

    2014-01-01

    LiNi 0.5 Mn 1.5 O 4 (LNMO) thin films have been deposited on stainless steel substrates using radio frequency (f = 13.56 MHz) magnetron sputtering, followed by thermal annealing in ambient atmosphere. Various negative biases were applied on the substrates during deposition. The structural evolution of LNMO thin films under different negative biases has been investigated and characterized by X-ray diffraction. All of the deposited films exhibit a crystalline spinel structure with a space group of Fd-3m, which is a so-called disordered phase. The results also indicate that particle size decreases with increasing negative bias. The electrochemical properties of the LNMO thin films as cathode materials for lithium ion batteries were investigated. Two distinctive voltage plateaus at ∼ 4.7 V and at ∼ 4.0 V (vs. Li + /Li) can be observed in the discharge curves, corresponding to the reactions of the disordered phase. The capacity of LNMO thin film electrodes under suitable negative bias can be optimized. - Highlights: • LiNi 0.5 Mn 1.5 O 4 thin films have been deposited on stainless steel substrates. • Various negative biases were applied on the substrates during deposition. • The particle sizes of LNMO thin films decrease with increasing negative bias

  3. Postprandial oxidative stress is increased after a phytonutrient-poor food but not after a kilojoule-matched phytonutrient-rich food.

    Science.gov (United States)

    Khor, Amanda; Grant, Ross; Tung, Chin; Guest, Jade; Pope, Belinda; Morris, Margaret; Bilgin, Ayse

    2014-05-01

    Research indicates that energy-dense foods increase inflammation and oxidative activity, thereby contributing to the development of vascular disease. However, it is not clear whether the high kilojoule load alone, irrespective of the nutritional content of the ingested food, produces the postprandial oxidative and inflammatory activity. This study investigated the hypothesis that ingestion of a high-fat, high-sugar, phytonutrient-reduced food (ice cream) would increase oxidative and inflammatory activity greater than a kilojoule-equivalent meal of a phytonutrient-rich whole food (avocado). The individual contributions of the fat/protein and sugar components of the ice cream meal to postprandial inflammation and oxidative stress were also quantified. Using a randomized, crossover design, 11 healthy participants ingested 4 test meals: ice cream, avocado, the fat/protein component in ice cream, and the sugar equivalent component in ice cream. Plasma glucose, cholesterol, triglycerides, and inflammatory and oxidative stress markers were measured at baseline and 1, 2, and 4 hours (t1, t2, t4) after ingestion. Lipid peroxidation was increased at 2 hours after eating fat/protein (t0-t2, P stress markers. These data indicate that the ingestion of a phytonutrient-poor food and its individual fat/protein or sugar components increase plasma oxidative activity. This is not observed after ingestion of a kilojoule-equivalent phytonutrient-rich food. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Process for producing uranium oxide rich compositions from uranium hexafluoride

    International Nuclear Information System (INIS)

    DeHollander, W.R.; Fenimore, C.P.

    1978-01-01

    Conversion of gaseous uranium hexafluoride to a uranium dioxide rich composition in the presence of an active flame in a reactor defining a reaction zone is achieved by separately introducing a first gaseous reactant comprising a mixture of uranium hexafluoride and a reducing carrier gas, and a second gaseous reactant comprising an oxygen-containing gas. The reactants are separated by a shielding gas as they are introduced to the reaction zone. The shielding gas temporarily separates the gaseous reactants and temporarily prevents substantial mixing and reacting of the gaseous reactants. The flame occurring in the reaction zone is maintained away from contact with the inlet introducing the mixture to the reaction zone. After suitable treatment, the uranium dioxide rich composition is capable of being fabricated into bodies of desired configuration for loading into nuclear fuel rods. Alternatively, an oxygen-containing gas as a third gaseous reactant is introduced when the uranium hexafluoride conversion to the uranium dioxide rich composition is substantially complete. This results in oxidizing the uranium dioxide rich composition to a higher oxide of uranium with conversion of any residual reducing gas to its oxidized form

  5. The properties and transport phenomena in oxide films on iron, nickel, chromium and their alloys in aqueous environments

    International Nuclear Information System (INIS)

    Laitinen, T.; Bojinov, M.; Betova, I.; Maekelae, K.; Saario, T.

    1999-01-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown pitting. Stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more compact structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  6. The properties and transport phenomena in oxide films on iron, nickel, chromium and their alloys in aqueous environments

    Energy Technology Data Exchange (ETDEWEB)

    Laitinen, T.; Bojinov, M.; Betova, I.; Maekelae, K.; Saario, T. [VTT Manufacturing Technology, Espoo (Finland)

    1999-01-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown pitting. Stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more compact structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  7. The application and study of an oxide-impregnated nickel-matrix cathode for Beijing proton linac

    International Nuclear Information System (INIS)

    Xia Dehong; Shi Rongjian

    1996-01-01

    A low power consumption oxide-impregnated nickel-matrix cathode used in the Duoplasmatron ion source of the Beijing Proton Linac (BPL) is presented. Its structure, treatment process of nickel-foam rubber on metal matrix surface and manufacture of dip coating carbonate are briefly introduced. The activation method and experiment results of the cathode are described. The principal factors which influence the cathode lifetime are discussed. The lifetime of the cathode is up to 2110 h while the extracted pulsed beam current is about 200 mA

  8. Microstructural evaluation of ceria-samaria-gadolinia-nickel oxide composite after reduction in hydrogen atmosphere

    International Nuclear Information System (INIS)

    Arakaki, A. R.; Yoshito, W.K.; Ussui, V.; Lazar, D.R.R.

    2012-01-01

    The ceria-samaria-gadolinia-nickel composite (Ni-SGDC), used as Solid Oxide Fuel Cell (SOFC) anode, was obtained by 'in situ' reduction of NiO-SGDC, with composition Ce 0,8 (SmGd) 0,2 O 1,9 /NiO and mass proportion 40:60%. The composite was produced by hydroxides coprecipitation using CTAB surfactant, followed by solvothermal treatment in butanol, calcination at 600 deg C, pressing and sintering at 1350 deg C for 1 h. The composite reduction kinetic was evaluated in a tubular furnace under dynamic atmosphere of 4% H2 /Air, fixing the temperature at 900 deg C and time between 10 and 120 minutes. The microstructural characterization was performed by optical and scanning electron microscopy. The samples were characterized either by X-ray diffraction and density measurements by immersion technique in water. It was verified that the NiO reduced fraction reached values between 80 and 90% and the achieved porosity (about 30%) is acceptable to a good anode performance (author)

  9. Promotion of Water-mediated Carbon Removal by Nanostructured Barium Oxide/nickel Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    L Yang; Y Choi; W Qin; H Chen; K Blinn; M Liu; P Liu; J Bai; T Tyson; M Liu

    2011-12-31

    The existing Ni-yttria-stabilized zirconia anodes in solid oxide fuel cells (SOFCs) perform poorly in carbon-containing fuels because of coking and deactivation at desired operating temperatures. Here we report a new anode with nanostructured barium oxide/nickel (BaO/Ni) interfaces for low-cost SOFCs, demonstrating high power density and stability in C{sub 3}H{sub 8}, CO and gasified carbon fuels at 750 C. Synchrotron-based X-ray analyses and microscopy reveal that nanosized BaO islands grow on the Ni surface, creating numerous nanostructured BaO/Ni interfaces that readily adsorb water and facilitate water-mediated carbon removal reactions. Density functional theory calculations predict that the dissociated OH from H2O on BaO reacts with C on Ni near the BaO/Ni interface to produce CO and H species, which are then electrochemically oxidized at the triple-phase boundaries of the anode. This anode offers potential for ushering in a new generation of SOFCs for efficient, low-emission conversion of readily available fuels to electricity.

  10. High-performance binder-free supercapacitor electrode by direct growth of cobalt-manganese composite oxide nansostructures on nickel foam

    Science.gov (United States)

    Jiang, Shulan; Shi, Tielin; Long, Hu; Sun, Yongming; Zhou, Wei; Tang, Zirong

    2014-09-01

    A facile approach composed of hydrothermal process and annealing treatment is proposed to directly grow cobalt-manganese composite oxide ((Co,Mn)3O4) nanostructures on three-dimensional (3D) conductive nickel (Ni) foam for a supercapacitor electrode. The as-fabricated porous electrode exhibits excellent rate capability and high specific capacitance of 840.2 F g-1 at the current density of 10 A g-1, and the electrode also shows excellent cycling performance, which retains 102% of its initial discharge capacitance after 7,000 cycles. The fabricated binder-free hierarchical composite electrode with superior electrochemical performance is a promising candidate for high-performance supercapacitors.

  11. Anodic characteristics and stress corrosion cracking behavior of nickel rich alloys in bicarbonate and buffer solutions

    International Nuclear Information System (INIS)

    Zadorozne, Natalia S.; Giordano, Mabel C.; Ares, Alicia E.; Carranza, Ricardo M.; Rebak, Raul B.

    2016-01-01

    Highlights: • We investigate which element in alloy C-22 may be responsible for the cracking susceptibility of the high nickel alloy. • Six nickel based alloys with different amount of Cr and Mo were selected for the electrochemical tests and response to SSRT. • Polarization tests showed that an anodic peak appear in the passive region in Cr containing alloys. • Cracking of Ni alloys in carbonate solutions seem to be a consequence of the instability of the passivating chromium oxide. • Alloys containing both Cr and Mo have the highest susceptibility. - Abstract: The aim of this work is to investigate which alloying element in C-22 is responsible for the cracking susceptibility of the alloy in bicarbonate and two buffer solutions (tungstate and borate). Six nickel based alloys, with different amount of chromium (Cr) and molybdenum (Mo) were tested using electrochemical methods and slow strain rate tests (SSRT) at 90 °C. All Cr containing alloys had transgranular cracking at high anodic potential; however, C-22 containing high Cr and high Mo was the most susceptible alloy to cracking. Bicarbonate was the most aggressive of three tested environments of similar pH.

  12. High temperature oxidation behaviour of nanostructured cermet coatings in a mixed CO2 – O2 environment

    International Nuclear Information System (INIS)

    Farrokhzad, M A; Khan, T I

    2014-01-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (α-Al 2 O3 and TiO 2 ) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500°C, 600°C and 700°C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15% CO 2 , 10% O 2 and 75% N 2 . This research investigates the effects of CO 2 and O 2 partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO 2 at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO 2 in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO2 acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO 2 particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Ni-Ti compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings

  13. Ultrasonic preparation of nano-nickel/activated carbon composite using spent electroless nickel plating bath and application in degradation of 2,6-dichlorophenol.

    Science.gov (United States)

    Su, Jingyu; Jin, Guanping; Li, Changyong; Zhu, Xiaohui; Dou, Yan; Li, Yong; Wang, Xin; Wang, Kunwei; Gu, Qianqian

    2014-11-01

    Ni was effectively recovered from spent electroless nickel (EN) plating baths by forming a nano-nickel coated activated carbon composite. With the aid of ultrasonication, melamine-formaldehyde-tetraoxalyl-ethylenediamine chelating resins were grafted on activated carbon (MFT/AC). PdCl2 sol was adsorbed on MFT/AC, which was then immersed in spent electroless nickel plating bath; then nano-nickel could be reduced by ascorbic acid to form a nano-nickel coating on the activated carbon composite (Ni/AC) in situ. The materials present were carefully examined by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemistry techniques. The resins were well distributed on the inside and outside surfaces of activated carbon with a size of 120 ± 30 nm in MFT/AC, and a great deal of nano-nickel particles were evenly deposited with a size of 3.8 ± 1.1 nm in Ni/MFT. Moreover, Ni/AC was successfully used as a catalyst for ultrasonic degradation of 2,6-dichlorophenol. Copyright © 2014. Published by Elsevier B.V.

  14. Nickel-catalyzed reactions of enone with ethylene

    International Nuclear Information System (INIS)

    Nishimura, A; Haba, T; Ohashi, M; Ogoshi, S

    2010-01-01

    The reaction of (E)-1-phenylbut-2-en-1-one with ethylene in the presence of a catalytic amount of Ni(cod) 2 and PCy 3 at room temperature gave two kinds of three-component addition products; one is 1,6-enone composed of an enone and two ethylene molecules, and the other is 1,5-diketone composed of two enones and an ethylene. The reactions might proceed via oxidative cyclization of an enone and an ethylene with nickel(0).

  15. Compatibility evaluation between La 2Mo 2O 9 fast oxide-ion conductor and Ni-based materials

    Science.gov (United States)

    Corbel, Gwenaël; Lacorre, Philippe

    2006-05-01

    The chemical reactivity of La 2NiO 4+δ and nickel metal or nickel oxide with fast oxide-ion conductor La 2Mo 2O 9 is investigated in the annealing temperature range between 600 and 1000 °C, using room temperature X-ray powder diffraction. Within the La 2NiO 4+δ/La 2Mo 2O 9 system, subsequent reaction is evidenced at relatively low annealing temperature (600 °C), with formation of La 2MoO 6 and NiO. The reaction is complete at 1000 °C. At reverse, no reaction occurs between Ni or NiO and La 2Mo 2O 9 up to 1000 °C. Together with a previous work [G. Corbel, S. Mestiri, P. Lacorre, Solid State Sci. 7 (2005) 1216], the current study shows that Ni-CGO cermets might be chemically and mechanically compatible anode materials to work with LAMOX electrolytes in solid oxide fuel cells.

  16. Linie Aquavit : taste that really travels

    OpenAIRE

    Flåten, Mats; Knudsen, Øyvind L.; Rosted, Ulrik; Rønning, Kim-André S.; Settemsdal, Simen E.

    2011-01-01

    This thesis presents the findings from a mainly descriptive research study about Chinese students‟ attitude towards alcohol and food. The research has been conducted on behalf of Arcus AS, from here on referred to as Arcus, concerning their long term goal of launching their product Linie Aquavit on the Chinese mainland market. In order to do this, Arcus needs to know more about their future target consumer segment in the Chinese market. Together, Arcus and the authors decided to do a research...

  17. Improved Cycling Stability of Cobalt-free Li-rich Oxides with a Stable Interface by Dual Doping

    International Nuclear Information System (INIS)

    Xie, Dongjiu; Li, Guangshe; Li, Qi; Fu, Chaochao; Fan, Jianming; Li, Liping

    2016-01-01

    Highlights: • Cobalt-free Na_xLi_1_._2_-_xMn_0_._6_-_xAl_xNi_0_._2O_2 oxides are prepared by a sol-gel method. • Dual-doping strengthens the covalence of Mn-O bonds and suppresses the side reactions between cathode and electrolyte. • Doped cathode has a capacity retention over 92.2% after 100 cycles at a high temperature of 55 °C. - Abstract: Li-rich cobalt-free oxides, popularly used as a cathode with high capacity in lithium ion battery, always suffer from poor cycling stability between 2.0 and 4.8 V vs Li"+/Li, especially when cycled at high temperatures (>50 °C). To overcome this issue, Na"+ and Al"3"+ dual-doped Na_xLi_1_._2_-_xMn_0_._6_-_xAl_xNi_0_._2O_2 Li-rich cathode is prepared in this study. It is shown that the side reactions between cathode and electrolyte during cycling are suppressed. The improved cycling performance is observed for all of the doped samples, among which the sample with x = 0.03 exhibits the highest capacity retention of 86.1% after 200 cycles between 2.0 and 4.8 V at 2C (1C = 200 mA g"−"1) and shows a remarkable cycling stability, even at a high temperature of 55 °C (a capacity retention of 92.2% after 100 cycles). Moreover, the average voltage of the sample with x = 0.03 after 100 cycles at 0.5C remains at 3.11 V with a retention ratio of 86.6%. This work provides a new strategy to develop Li-rich cobalt-free cathodes with excellent cycling stability for lithium ion batteries at high temperatures.

  18. Global nickel anomaly links Siberian Traps eruptions and the latest Permian mass extinction.

    Science.gov (United States)

    Rampino, Michael R; Rodriguez, Sedelia; Baransky, Eva; Cai, Yue

    2017-09-29

    Anomalous peaks of nickel abundance have been reported in Permian-Triassic boundary sections in China, Israel, Eastern Europe, Spitzbergen, and the Austrian Carnic Alps. New solution ICP-MS results of enhanced nickel from P-T boundary sections in Hungary, Japan, and Spiti, India suggest that the nickel anomalies at the end of the Permian were a worldwide phenomenon. We propose that the source of the nickel anomalies at the P-T boundary were Ni-rich volatiles released by the Siberian volcanism, and by coeval Ni-rich magma intrusions. The peaks in nickel abundance correlate with negative δ 13 C and δ 18 O anomalies, suggesting that explosive reactions between magma and coal during the Siberian flood-basalt eruptions released large amounts of CO 2 and CH 4 into the atmosphere, causing severe global warming and subsequent mass extinction. The nickel anomalies may provide a timeline in P-T boundary sections, and the timing of the peaks supports the Siberian Traps as a contributor to the latest Permian mass extinction.

  19. High temperature oxidation behavior of gamma-nickel+gamma'-nickel aluminum alloys and coatings modified with platinum and reactive elements

    Science.gov (United States)

    Mu, Nan

    Materials for high-pressure turbine blades must be able to operate in the high-temperature gases (above 1000°C) emerging from the combustion chamber. Accordingly, the development of nickel-based superalloys has been constantly motivated by the need to have improved engine efficiency, reliability and service lifetime under the harsh conditions imposed by the turbine environment. However, the melting point of nickel (1455°C) provides a natural ceiling for the temperature capability of nickel-based superalloys. Thus, surface-engineered turbine components with modified diffusion coatings and overlay coatings are used. Theses coatings are capable of forming a compact and adherent oxide scale, which greatly impedes the further transport of reactants between the high-temperature gases and the underlying metal and thus reducing attack by the atmosphere. Typically, these coatings contain beta-NiAl as a principal constituent phase in order to have sufficient aluminum content to form an Al2O3 scale at elevated temperatures. The drawbacks to the currently-used beta-based coatings, such as phase instabilities, associated stresses induced by such phase instabilities, and extensive coating/substrate interdiffusion, are major motivations in this study to seek next-generation coatings. The high-temperature oxidation resistance of novel Pt+Hf-modified gamma-Ni+gamma'-Ni 3Al-based alloys and coatings were investigated in this study. Both early-stage and 4-days isothermal oxidation behavior of single-phase gamma-Ni and gamma'-Ni3Al alloys were assessed by examining the weight changes, oxide-scale structures, and elemental concentration profiles through the scales and subsurface alloy regions. It was found that Pt promotes Al 2O3 formation by suppressing the NiO growth on both gamma-Ni and gamma'-Ni3Al single-phase alloys. This effect increases with increasing Pt content. Moreover, Pt exhibits this effect even at lower temperatures (˜970°C) in the very early stage of oxidation. It

  20. Associations of neonatal lead, cadmium, chromium and nickel co-exposure with DNA oxidative damage in an electronic waste recycling town

    International Nuclear Information System (INIS)

    Ni, Wenqing; Huang, Yue; Wang, Xiaoling; Zhang, Jingwen; Wu, Kusheng

    2014-01-01

    Objective: This study aimed to evaluate the effects of toxic heavy metal co-exposure on DNA oxidative damage in neonates from a primitive e-waste recycling region, Guiyu town, China. Methods: Our participants included 201 pregnant women: 126 from Guiyu town and 75 from Jinping district of Shantou city, where no e-waste recycling and dismantling activities existed. Structured interview questionnaires were administered to the pregnant women and umbilical cord blood (UCB) samples were collected after delivery. The UCB concentrations of lead, cadmium, chromium, and nickel were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Levels of UCB plasma 8-hydroxydeoxyguanosine (8-OHdG, a DNA oxidative damage biomarker) were determined by enzyme-linked immunosorbent assay. Results: Our results suggested that UCB lead and cadmium concentrations in neonates of Guiyu were significantly higher than those of Jinping (lead: median 110.45 ng/mL vs. 57.31 ng/mL; cadmium: median 2.50 ng/mL vs. 0.33 ng/mL, both P < 0.001). Parents' residence in Guiyu, and parents' work related to e-waste recycling were the risk factors associated with neonate's UCB lead and cadmium levels. No significant difference of UCB plasma 8-OHdG levels was found between Guiyu and the control area. After adjusting for potential confounders, cord plasma 8-OHdG concentrations (ng/mL) were positively associated with blood cadmium (β = 0.126 ng/mL, 95% CI: 0.055 to 0.198 ng/mL), chromium (β = 0.086 ng/mL, 95% CI: 0.014 to 0.158 ng/mL) and nickel (β = 0.215 ng/mL, 95% CI: 0.113 to 0.317 ng/mL) concentrations. Conclusions: The primitive e-waste recycling and dismantling activities may contribute to the elevated umbilical cord blood toxic heavy metal levels in neonates born in Guiyu. Exposures to cadmium, chromium and nickel were associated with increased oxidative DNA damage in neonates. - Highlights: • DNA oxidative damage levels (8-OHdG) in neonates from Guiyu were assessed. • Neonatal lead

  1. Associations of neonatal lead, cadmium, chromium and nickel co-exposure with DNA oxidative damage in an electronic waste recycling town

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Wenqing; Huang, Yue; Wang, Xiaoling; Zhang, Jingwen; Wu, Kusheng, E-mail: kswu@stu.edu.cn

    2014-02-01

    Objective: This study aimed to evaluate the effects of toxic heavy metal co-exposure on DNA oxidative damage in neonates from a primitive e-waste recycling region, Guiyu town, China. Methods: Our participants included 201 pregnant women: 126 from Guiyu town and 75 from Jinping district of Shantou city, where no e-waste recycling and dismantling activities existed. Structured interview questionnaires were administered to the pregnant women and umbilical cord blood (UCB) samples were collected after delivery. The UCB concentrations of lead, cadmium, chromium, and nickel were analyzed by graphite furnace atomic absorption spectrometry (GFAAS). Levels of UCB plasma 8-hydroxydeoxyguanosine (8-OHdG, a DNA oxidative damage biomarker) were determined by enzyme-linked immunosorbent assay. Results: Our results suggested that UCB lead and cadmium concentrations in neonates of Guiyu were significantly higher than those of Jinping (lead: median 110.45 ng/mL vs. 57.31 ng/mL; cadmium: median 2.50 ng/mL vs. 0.33 ng/mL, both P < 0.001). Parents' residence in Guiyu, and parents' work related to e-waste recycling were the risk factors associated with neonate's UCB lead and cadmium levels. No significant difference of UCB plasma 8-OHdG levels was found between Guiyu and the control area. After adjusting for potential confounders, cord plasma 8-OHdG concentrations (ng/mL) were positively associated with blood cadmium (β = 0.126 ng/mL, 95% CI: 0.055 to 0.198 ng/mL), chromium (β = 0.086 ng/mL, 95% CI: 0.014 to 0.158 ng/mL) and nickel (β = 0.215 ng/mL, 95% CI: 0.113 to 0.317 ng/mL) concentrations. Conclusions: The primitive e-waste recycling and dismantling activities may contribute to the elevated umbilical cord blood toxic heavy metal levels in neonates born in Guiyu. Exposures to cadmium, chromium and nickel were associated with increased oxidative DNA damage in neonates. - Highlights: • DNA oxidative damage levels (8-OHdG) in neonates from Guiyu were assessed.

  2. Tuning crystal phase of NiS_x through electro-oxidized nickel foam: A novel route for preparing efficient electrocatalysts for oxygen evolution reaction

    International Nuclear Information System (INIS)

    Li, Xiao; Shang, Xiao; Rao, Yi; Dong, Bin; Han, Guan-Qun; Hu, Wen-Hui; Liu, Yan-Ru; Yan, Kai-Li; Chi, Jing-Qi; Chai, Yong-Ming; Liu, Chen-Guang

    2017-01-01

    Highlights: • Electro-oxidized nickel foam as a support has been used to prepare NiS_x phases. • Ni(OH)_2 layer on electro-oxidized NF is responsible for the growth of β-NiS. • NiS_x/NF(Ox) composed of β-NiS and Ni_3S_2 has enhanced electrocatalytic activity. • The growth mechanisms of mixed NiS_x phases of NiS_x/NF(Ox) have been discussed. - Abstract: A facile solvothermal sulfurization using electro-oxidized nickel foam (NF(Ox)) as support has been applied to prepare NiS_x/NF(Ox) electrocatalyst with highly efficient activity for oxygen evolution reaction (OER). XRD patterns confirm the composition of NiS_x/NF(Ox): two kinds of crystal phase including β-NiS and Ni_3S_2. While using bare NF as support under identical conditions, only Ni_3S_2 phase can be detected. SEM images reveal two kinds of morphologies of NiS_x/NF(Ox) including pyramids structure of β-NiS and nanorod-like structure of Ni_3S_2, which implies the tuning effect of electro-pretreatment of NF on the selective preparation of NiS_x crystal phase. It can be speculated that Ni(OH)_2 layer derived from electro-oxidized NF is responsible for the growth of β-NiS while metallic Ni is transformed into Ni_2S_3 during sulfurization. Electrochemical measurements for OER indicate the enhanced electrocatalytic activity of NiS_x/NF(Ox) with a small overpotential of 72 mV to reach 10 mA cm"−"2 compared with Ni_3S_2/NF, which may be ascribed to the improved electron-transfer kinetics relating to the unique atomic configurations and crystalline structures of β-NiS. The electro-oxidation pretreatment of nickel foam provides a simple and convenient method by tuning different NiS_x crystal phases for preparing excellent OER eletrocatalysts.

  3. Solubility of nickel-cadmium ferrite in acids

    International Nuclear Information System (INIS)

    Vol'ski, V.; Vol'ska, Eh.; Politan'ska, U.

    1977-01-01

    The solubility of a solid solution of nickel-cadmium ferrite containing an excess of ferric oxide, (CdO)sub(0.5), (NiO)sub(0.5) and (Fe 2 O 3 )sub(1.5), in hydrochloric and nitric acids at 20, 40 and 60 deg C, was determined colorimetrically and chelatometrically, as well as by studying the x-ray diffraction patterns of the preparations prior to dissolution and their residues after dissolution. It is shown that cadmium passes into the solution faster than iron and nickel; after 800 hours, the solution contains 40% of iron ions and more than 80% of cadmium ions. The kinetics of ferrite dissolution is studied

  4. Selective sodium intercalation into sodium nickel-manganese sulfate for dual Na-Li-ion batteries.

    Science.gov (United States)

    Marinova, Delyana M; Kukeva, Rosica R; Zhecheva, Ekaterina N; Stoyanova, Radostina K

    2018-04-26

    Double sodium transition metal sulfates combine in themselves unique intercalation properties with eco-compatible compositions - a specific feature that makes them attractive electrode materials for lithium and sodium ion batteries. Herein, we examine the intercalation properties of novel double sodium nickel-manganese sulfate, Na2Ni1/2Mn1/2(SO4)2, having a large monoclinic unit cell, through electrochemical and ex situ diffraction and spectroscopic methods. The sulfate salt Na2Ni1/2Mn1/2(SO4)2 is prepared by thermal dehydration of the corresponding hydrate salt Na2Ni1/2Mn1/2(SO4)2·4H2O having a blödite structure. The intercalation reactions on Na2Ni1-xMnx(SO4)2 are studied in two model cells: half-ion cell versus Li metal anode and full-ion cell versus Li4Ti5O12 anode by using lithium (LiPF6 dissolved in EC/DMC) and sodium electrolytes (NaPF6 dissolved in EC:DEC). Based on ex situ XRD and TEM analysis, it is found that sodium intercalation into Na2Ni1/2Mn1/2(SO4)2 takes place via phase separation into the Ni-rich monoclinic phase and Mn-rich alluaudite phase. The redox reactions involving participation of manganese and titanium ions are monitored by ex situ EPR spectroscopy. It has been demonstrated that manganese ions from the sulfate salt are participating in the electrochemical reaction, while the nickel ions remain intact. As a result, a reversible capacity of about 65 mA h g-1 is reached. The selective intercalation properties determine sodium nickel-manganese sulfate as a new electrode material for hybrid lithium-sodium ion batteries that is thought to combine the advantages of individual lithium and sodium batteries.

  5. Reverse microemulsion synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide nanocomposites for high-performance supercapacitors and sodium ion batteries

    Science.gov (United States)

    Qiu, Xiaoming; Liu, Yongchang; Wang, Luning; Fan, Li-Zhen

    2018-03-01

    Prussian blue analogues with tunable open channels are of fundamental and technological importance for energy storage systems. Herein, a novel facile synthesis of nickel-cobalt hexacyanoferrate/reduced graphene oxide (denoted as Ni-CoHCF/rGO) nanocomposite is realized by a reverse microemulsion method. The very fine Ni-CoHCF nanoparticles (10-20 nm) are homogeneously anchored on the surface of reduced graphene oxide by electrostatic adsorption and reduced graphene oxide is well-separated by Ni-CoHCF particles. Benefiting from the combined advantages of this structure, the Ni-. It CoHCF/rGO nanocomposite can be used as electrodes for both supercapacitors and sodium ion batteries exhibits excellent pseudocapacitve performance in terms of high specific capacitance of 466 F g-1 at 0.2 A g-1 and 350 F g-1 at 10 A g-1, along with high cycling stabilities. As a cathode material for sodium ion batteries, it also demonstrates a high reversible capacity of 118 mAh g-1 at 0.1 A g-1, good rate capability, and superior cycling stability. These results suggest its potential as an efficient electrode for high-performance energy storage and renewable delivery devices.

  6. Investigation of Electrical and Optical Characteristics of Nanohybride Composite (Polyvinyl Alcohol / Nickel Oxide

    Directory of Open Access Journals (Sweden)

    A. Hayati

    2014-01-01

    Full Text Available Some issues; leakage, tunneling currents, boron diffusion are threatening SiO2 to be used as a good gate dielectric for the future of the CMOS (complementary metal- oxide- semiconductor transistors. For finding an alternative and novel gate dielectric, the NiO (Nickel oxide and PVA (polyvinyl alcohol nano powders were synthesized with the sol-gel method and their nano structural properties were studied using the X-ray diffraction (XRD, Atomic force microscopy (AFM, Scanning electron microscopy (SEM, UV-Vis spectrophotometer and GPS 132 techniques. The obtained results indicated that the sample (5 g NiO and 0.02g PVA prepared at 30˚C, annealed in an oven at a temperature of 80˚C can fill this gap due to its higher dielectric constant, better morphology, less rough surface and less leakage current.

  7. Conversion of Methane into Methanol and Ethanol over Nickel Oxide on Ceria-Zirconia Catalysts in a Single Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Okolie, Chukwuemeka [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Belhseine, Yasmeen F. [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Lyu, Yimeng [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA; Yung, Matthew M. [National Renewable Energy Laboratory, Golden CO 80401 USA; Engelhard, Mark H. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Lab, Richland WA 99354 USA; Kovarik, Libor [Environmental Molecular Sciences Laboratory, Pacific Northwest National Lab, Richland WA 99354 USA; Stavitski, Eli [National Synchrotron Light Source II, Brookhaven National Laboratory, Upton NY 11973 USA; Sievers, Carsten [School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW Atlanta GA 30332 USA

    2017-09-26

    Direct conversion of methane into alcohols is a promising technology for converting stranded methane reserves into liquids that can be transported in pipelines and upgraded to value-added chemicals. We demonstrate that a catalyst consisting of small nickel oxide clusters supported on ceria-zirconia (NiO/CZ) can selectively oxidize methane to methanol and ethanol in a single, steady-state process at 723 K using O2 as an abundantly available oxidant. The presence of steam is required to obtain alcohols rather than CO2 as the product of catalytic combustion. The unusual activity of this catalyst is attributed to the synergy between the small Lewis acidic NiO clusters and the redox-active CZ support, which also stabilizes the small NiO clusters.

  8. Cycle aging studies of lithium nickel manganese cobalt oxide-based batteries using electrochemical impedance spectroscopy

    NARCIS (Netherlands)

    Maheshwari, Arpit; Heck, Michael; Santarelli, Massimo

    2018-01-01

    The cycle aging of a commercial 18650 lithium-ion battery with graphite anode and lithium nickel manganese cobalt (NMC) oxide-based cathode at defined operating conditions is studied by regular electrochemical characterization, electrochemical impedance spectroscopy (EIS) and post-mortem analysis.

  9. Thermogravimetric study of reduction of oxides present in oxidized nickel-base alloy powders

    Science.gov (United States)

    Herbell, T. P.

    1976-01-01

    Carbon, hydrogen, and hydrogen plus carbon reduction of three oxidized nickel-base alloy powders (a solid solution strengthened alloy both with and without the gamma prime formers aluminum and titanium and the solid solution strengthened alloy NiCrAlY) were evaluated by thermogravimetry. Hydrogen and hydrogen plus carbon were completely effective in reducing an alloy containing chromium, columbium, tantalum, molybdenum, and tungsten. However, with aluminum and titanium present the reduction was limited to a weight loss of about 81 percent. Carbon alone was not effective in reducing any of the alloys, and none of the reducing conditions were effective for use with NiCrAlY.

  10. Synthesis of Three-Dimensional Nanoporous Li-Rich Layered Cathode Oxides for High Volumetric and Power Energy Density Lithium-Ion Batteries.

    Science.gov (United States)

    Qiu, Bao; Yin, Chong; Xia, Yonggao; Liu, Zhaoping

    2017-02-01

    As rechargeable Li-ion batteries have expanded their applications into on-board energy storage for electric vehicles, the energy and power must be increased to meet the new demands. Li-rich layered oxides are one of the most promising candidate materials; however, it is very difficult to make them compatible with high volumetric energy density and power density. Here, we develop an innovative approach to synthesize three-dimensional (3D) nanoporous Li-rich layered oxides Li[Li 0.144 Ni 0.136 Co 0.136 Mn 0.544 ]O 2 , directly occurring at deep chemical delithiation with carbon dioxide. It is found that the as-prepared material presents a micrometer-sized spherical structure that is typically composed of interconnected nanosized subunits with narrow distributed pores at 3.6 nm. As a result, this unique 3D micro-/nanostructure not only has a high tap density over 2.20 g cm -3 but also exhibits excellent rate capability (197.6 mA h g -1 at 1250 mA g -1 ) as an electrode. The excellent electrochemical performance is ascribed to the unique nanoporous micro-nanostructures, which facilitates the Li + diffusion and enhances the structural stability of the Li-rich layered cathode materials. Our work offers a comprehensive designing strategy to construct 3D nanoporous Li-rich layered oxides for both high volumetric energy density and power density in Li-ion batteries.

  11. The Properties Of And Transport Phenomena In Oxide Films On Iron, Nickel, Chromium And Their Alloys In Aqueous Environments

    International Nuclear Information System (INIS)

    Saario, T.; Laitinen, T.; Maekelae, K.; Bojinov, M.; Betova, I.

    1998-07-01

    The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk oxides, the structure and properties of oxide films forming on pure iron, nickel and chromium and on iron- and nickel-based engineering alloys are considered. General approaches to model the structure and growth of oxide films on metals are discussed in detail. The specific features of the oxide structures, properties and growth at high temperatures are presented with special focus on the relevance of existing models. Finally, the role of oxide films in localised corrosion, oxide breakdown, pitting, stress corrosion cracking and related phenomena is considered. The films formed on the surfaces of iron- and nickel-based alloys in high-temperature aqueous environments generally comprise two layers, i.e. the so-called duplex structure. The inner part is normally enriched in chromium and has a more dense structure, while the outer part is enriched in iron and has a cracked or porous structure. The information collected clearly indicates the effect of the chemical environment on the properties of oxide films growing on metal surfaces

  12. High temperature oxidation behaviour of nanostructured cermet coatings in amixed CO/sub 2/ - O/sub 2/ environment

    International Nuclear Information System (INIS)

    Farrokhzad, M. A.; Khan, T. I.

    2013-01-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (alpha-Al /sub 2/O/sub 3/ and TiO/sub 2/) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500 degree C, 600 degree C and 700 degree C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15 percentage CO/sub 2/, 10 percentage O/sub 2/ and 75 percentage N/sub 2/. This research investigates the effects of CO/sub 2/ and O/sub 2/ partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO/sub 2/ at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO/sub 2/ in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO/sub 2/ acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO/sub 2/ particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Nu i-Tau i compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings. (author)

  13. An Electrochemical Investigation of Methanol Oxidation on Nickel ...

    African Journals Online (AJOL)

    NICO

    Cyclic voltammetry, electrooxidation, glassy carbon electrode, methanol, nickel hydroxide nanoparticles. 1. ... substrate at room temperature without templates. Recently, we ... placed in ethanol and sonicated to remove adsorbed particles.

  14. Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2).

    Science.gov (United States)

    AbouEl-Enein, S A; El-Saied, F A; Kasher, T I; El-Wardany, A H

    2007-07-01

    Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency.

  15. Quenching effect on creep of polycrystal nickel at 1.5-4.2 K

    International Nuclear Information System (INIS)

    Gindin, I.A.; Starodubov, Ya.D.; Aksenov, V.K.; Karaseva, E.V.

    1977-01-01

    Stepwise creep of vacuum-remelted nickel of 99.996% purity at temperatures of 1.5; 2.2 and 4.2 K in the initial and hardened state was studied. It has been established that excess concentration of vacancies reduced the creep rate, especially at low applied stresses (sigma 0.4 sigmasub(B) (T=const) the creep characteristics only slightly depend on the specimen prehistory. The creep of hardened and initial specimens in the investigated temperature range is of an athermal nature up to sigma <= 0.8 sigmasub(B), but at higher stresses an increase in temperature from 1.5 to 4.2 K increases the rate of nonstationary creep of both initial and hardened specimens. The causes for the regularities observed are discussed

  16. Evaluation of Heat Capacity and Resistance to Cyclic Oxidation of Nickel Superalloys

    Directory of Open Access Journals (Sweden)

    Przeliorz R.

    2014-08-01

    Full Text Available Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1 hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance. Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation processes (γ′, γ″ are probably occurring, resulting in a sudden increase in the observed heat capacity.

  17. Influence of the alloy composition on the oxidation and internal-nitridation behaviour of nickel-base superalloys

    International Nuclear Information System (INIS)

    Krupp, U.; Christ, H.-J.

    1999-01-01

    Internal nitridation of nickel-base superalloys takes place as a consequence of the failure of protecting oxide scales (Al 2 O 3 and Cr 2 O 3 , respectively) and leads to a deterioration of the material properties due to near-surface embrittlement caused by the nitrides precipitated (TiN and AlN, respectively) and due to near-surface dissolution of the γ' phase. By using thermogravimetric methods in a temperature range between 800 C and 1100 C supplemented by microstructural examinations, the failure potential due to internal nitridation could be documented. A quantification was carried out by extending the experimental program to thermogravimetric studies in a nearly oxygen-free nitrogen atmosphere which was also applied to various model alloys of the system Ni-Cr-Al-Ti. It could be shown that the nitrogen diffusivity and solubility in nickel-base alloys is influenced particularly by the chromium concentration. An increasing chromium content leads to an enhanced internal-nitridation attack. (orig.)

  18. Nanoscale investigation of the interface situation of plated nickel and thermally formed nickel silicide for silicon solar cell metallization

    Energy Technology Data Exchange (ETDEWEB)

    Mondon, A., E-mail: andrew.mondon@ise.fraunhofer.de [Fraunhofer ISE, Heidenhofst. 2, D-79110 Freiburg (Germany); Wang, D. [Karlsruhe Nano Micro Facility (KNMF), H.-von-Helmholz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Zuschlag, A. [Universität Konstanz FB Physik, Jacob-Burckhardt-Str. 27, D-78464 Konstanz (Germany); Bartsch, J.; Glatthaar, M.; Glunz, S.W. [Fraunhofer ISE, Heidenhofst. 2, D-79110 Freiburg (Germany)

    2014-12-30

    Highlights: • Adhesion of metallization of fully plated nickel–copper contacts on silicon solar cells can be achieved by formation of nickel silicide at the cost of degraded cell performance. • Understanding of silicide growth mechanisms and controlled growth may lead to high performance together with excellent adhesion. • Silicide formation is well known from CMOS production from PVD-Ni on flat surfaces. Yet the deposition methods and therefore layer characteristics and the surface topography are different for plated metallization. • TEM analysis is performed for differently processed samples. • A nickel silicide growth model is created for plated Ni on textured silicon solar cells. - Abstract: In the context of nickel silicide formation from plated nickel layers for solar cell metallization, there are several open questions regarding contact adhesion and electrical properties. Nanoscale characterization by transmission electron microscopy has been employed to support these investigations. Interfacial oxides and silicide phases were investigated on differently prepared samples by different analytical methods associated with transmission electron microscopy analysis. Processing variations included the pre-treatment of samples before nickel plating, the used plating solution and the thermal budget for the nickel–silicon solid-state reaction. It was shown that interface oxides of only few nm thickness on both silicon and nickel silicide are present on the samples, depending on the chosen process sequence, which have been shown to play an important role in adhesion of nickel on silicide in an earlier publication. From sample pretreatment variations, conclusions about the role of an interfacial oxide in silicide formation and its influence on phase formation were drawn. Such an oxide layer hinders silicide formation except for pinhole sites. This reduces the availability of Ni and causes a silicide with low Ni content to form. Without an interfacial oxide

  19. Nickel exposure and prevalent albuminuria and β2-microglobulinuria: evidence from a population-based study.

    Science.gov (United States)

    Liu, Gang; Sun, Qi; Zhu, Mingjiang; Sun, Liang; Wang, Zhenzhen; Li, Huaixing; Li, Zi; Chen, Yan; Yin, Huiyong; Lin, Xu

    2016-05-01

    High exposure to nickel could induce renal dysfunction in rodents and occupational workers. However, little is known about the effects of non-occupational exposure to nickel on renal health in the general population. We aimed to examine the associations of urinary nickel concentrations with albuminuria and β2-microglobulinuria in Chinese adults. 2115 non-institutionalised Chinese men and women aged 55-76 years from Beijing and Shanghai were included. Urinary nickel concentrations were assessed by inductively coupled plasma mass spectroscopy. Plasma uric acid, urea nitrogen, C reactive protein and urinary albumin, β2-microglobulin and creatinine were measured. Albuminuria was defined as urinary albumin ≥30 mg/g creatinine, and β2-microglobulinuria was defined as urinary β2-microglobulin ≥200 µg/g creatinine. Median concentration of urinary nickel was 3.95 μg/g creatinine (IQR: 2.57-6.71 μg/g creatinine), and prevalence of albuminuria, β2-microglobulinuria and both albuminuria and β2-microglobulinuria was 22.1%, 24.5% and 9.7%, respectively. Comparing the highest with the lowest quartile of urinary nickel, the ORs (95% CIs) were 1.99 (1.46 to 2.78) for albuminuria, 1.44 (1.07 to 1.95) for β2-microglobulinuria, and 2.95 (1.74 to 4.97) for both albuminuria and β2-microglobulinuria, after adjustment for demographic characteristics, lifestyle behaviours, body mass index, hypertension and diabetes. The association remained significant when further controlling for inflammatory markers or other heavy metals (all p trend nickel levels were positively associated with albuminuria and β2-microglobulinuria in Chinese men and women, who had relatively low background nickel exposure. More prospective studies are needed to confirm our findings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  20. Preparation and characterization of 6-layered functionally graded nickel-alumina (Ni-Al2O3) composites

    Science.gov (United States)

    Latiff, M. I. A.; Nuruzzaman, D. M.; Basri, S.; Ismail, N. M.; Jamaludin, S. N. S.; Kamaruzaman, F. F.

    2018-04-01

    The present research study deals with the preparation of 6-layered functionally graded (FG) metal-ceramic composite materials through powder metallurgy technique. Using a cylindrical die-punch set made of steel, the nickel-alumina (Ni-Al2O3) graded composite structure was fabricated. The samples consist of four gradual inter layers of varied nickel composition (80wt.%, 60wt.%, 40wt.%, 20wt.%) sandwiched with pure Ni and Al2O3 powders at the ends (100wt.% and 0wt.% nickel) were fabricated under 30 ton compaction load using a hydraulic press. After that, two-step sintering was carried out at sintering temperature 1200ºC and soaking time 3 hours was maintained in a tube furnace. The properties of the prepared samples were characterized by radial shrinkage, optical microscopy and hardness testing. Results showed that larger shrinkage occurred within the ceramic phase which proves that more porosities were eliminated in the ceramic rich layers. From the microstructural analysis, it was observed that alumina particles are almost uniformly distributed in nickel matrix, so as nickel particles in the ceramic matrix of alumina-dominant layers. From interfacial analyses, it was observed that a smooth transition in microstructure from one layer to the next confirms a good interfacial solid state bonding between metal-ceramic constituents and good compaction process. On the other hand, microhardness test results suggest that there might be increasing percentage of porosities in the graded structure as the ceramic content rises.

  1. Kinetics and thermodynamics of the dissolution of Th1-xMxO2 solid solutions (M = U, Pu)

    International Nuclear Information System (INIS)

    Hubert, S.; Heisbourg, G.; Dacheux, N.; Moisy, Ph.; Purans, J.

    2004-01-01

    Kinetics of the dissolution of Th 1-x M x O 2 (M = U, Pu) solid solutions was investigated as a function of several chemical parameters such as pH, substitution ratio, temperature, ionic strength, and electrolyte. Several compositions of Th 1-x U x O 2 and Th 1-x Pu x O 2 were synthesized and characterized before and after leaching by using several methods such as XRD, EXAFS, BET, PIXE, SEM, and XPS. Leaching tests were performed in nitric, hydrochloric or sulfuric media and groundwater. The normalized dissolution rates were evaluated for Th 1-x U x O 2 , and Th 0.88 Pu 0.12 O 2 leading to the determination of the partial order related to the proton concentration, n, and to the corresponding normalized dissolution rate constant at pH = 0, k'T. While for Th enriched solids, the solid solutions Th 1-x U x O 2 have the same dissolution behaviour than ThO 2 with a partial order n ∼ 0.3, in the case of uranium enriched solids, Th 1-x U x O 2 has the same dissolution behaviour than UO 2 with a partial order of n = 1, indicating that uranium oxidation rate becomes the limiting step of the dissolution process. The stoichiometry of the release of both actinides (U or Pu, Th) was verified until the precipitation of thorium occurred in the leachate for pH > 2, while uranium was released in the solution as an uranyl form. For uranium enriched solid solutions, thermodynamic equilibrium was reached after 100 days, and solubility constant of secondary phase was determined. In the case of Th 1-x Pu x O 2 , the dissolution behaviour is similar to that of ThO 2 , but only kinetic aspect of the dissolution can be studied. From the analysis of XPS and EXAFS data on leached and un-leached Th 1-x U x O 2 samples, the dissolution mechanism of solid solutions was explained and will be discussed. The role of the electrolytes on the dissolution of the solid solutions is discussed. Kinetics parameters of dissolution are also given in groundwater and in neutral media

  2. 2-Mercaptobenzimidazole, 2-Mercaptobenzothiazole, and Thioglycolic Acid in an Electroless Nickel-Plating Bath

    Directory of Open Access Journals (Sweden)

    Ahmet Ozan Gezerman

    2015-01-01

    Full Text Available The use of three different materials, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid, was investigated to improve the performance of electroless nickel-plating baths. By changing the concentrations of these materials, sample plates were coated. Optical microscope images were obtained by selecting representative coated plates. From the results of the investigations, the effects of these materials on electroless nickel plating were observed, and the most appropriate amounts of these materials for nickel plating were determined. Moreover, the nickel plating speed observed with the bath solution containing 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, and thioglycolic acid is higher than that in the case of traditional electroless plating baths, but the nickel consumption amount in the former case is lower. In order to minimize the waste water generated from electroless nickel-plating baths, we determined the lowest amounts of the chemicals that can be used for the concentrations reported in the literature.

  3. Influence of N-Oxide Introduction on the Stability of Nitrogen-Rich Heteroaromatic Rings: A Quantum Chemical Study.

    Science.gov (United States)

    Yuan, Jia; Long, Xinping; Zhang, Chaoyang

    2016-12-01

    N-Oxidization is an important strategy for enhancing the density and energy of energetic materials. Nevertheless, the influence of N + -O - introduction on molecular stability remains relatively unknown. Thus, the present work comprehensively studied 102 basic N-rich ring structures, including azoles, furazans, and azines, as well as their N-oxides by quantum chemical calculations. The introduction of N + -O - weakens molecular stability in most cases because the process elongates chemical bonds, decreases ring aromaticity, narrows the gaps between the highest occupied and lowest unoccupied molecular orbitals, and increases the photochemical reactivity. Besides, the easy H transfer to the neighboring O atom, which forms a N-OH isomer in azoles, renders the stabilization by N-oxide introduction ineffective. However, N-oxide introduction can enhance the molecular stability of 1,2,3,4-tetrazine-1,3-dioxide and tetrazino-tetrazine 1,3,6,8-tetraoxide by promoting σ-π separation and relieving lone-pair repulsion. Moreover, the alternate arrangement of positive and negative charges is another factor stabilizing the 1,2,3,4-tetrazine ring by 1,3-dioxidation. Finally, we assess the accessibility of N-oxidized azoles and azines by regarding N 2 O and H 2 O 2 as oxidizers. We find that all the oxidations were exothermic, thermodynamically spontaneous, and kinetically feasible. After an overall evaluation, we propose 19 N-oxides as basic structures for high-energy materials with considerable stability.

  4. Synthesis of LiNixFe1−xPO4 solid solution as cathode materials for lithium ion batteries

    International Nuclear Information System (INIS)

    Qing, Rui; Yang, Ming-Che; Meng, Ying Shirley; Sigmund, Wolfgang

    2013-01-01

    Highlights: • Phase pure LiNi x Fe 1−x PO 4 and LiNi x Fe 1−x PO 4 /C nanocomposites were obtained via a solid state reaction method. • Crystallite sizes were around 50 nm. Linear relationship was observed between lattice parameters and chemical composition. • Synthesized materials displayed electronic conductivity similar to reported value of LiFePO 4 . Carbon coating increased the conductivity to ∼10 −3 S/cm. • Chemical delithiation via NO 2 BF 4 extracted more than 90% of lithium from the nanocomposites, proving that Ni 2+ /Ni 3+ redox couple was activated. -- Abstract: Nanosize LiNi x Fe 1−x PO 4 solid solution and LiNi x Fe 1−x PO 4 /C nanocomposites were prepared via a solid state reaction method under argon atmosphere. A single phase olivine-type structure with Pnma space group was determined by X-ray diffraction. Crystallite sizes were found to be around 50 nm. A linear relationship was observed between lattice parameters and chemical composition which follows Vegard's law. Synthesized materials displayed electronic conductivity similar to previous reported values of LiFePO 4 . Carbon coating further increased the overall conductivity of nanocomposites to the order of 10 −3 S/cm. Chemical delithiation via NO 2 BF 4 oxidant extracted more than 95% of lithium from the solid solution material accompanied by a decrease in lattice parameters

  5. Synthesis and electrochemical properties of layered structure Li[Ni0.5Co0.25Mn0.25]O2 cathode material

    International Nuclear Information System (INIS)

    Prathibha, G.; Rosaiah, P.; Reddy, B. Purusottam; Ganesh, K. Sivajee; Hussain, O. M.

    2015-01-01

    Lithium ion (Li-ion) batteries are currently the energy source of choice for cell phones, laptops, and other mobile electronic devices due to their balance of high energy density with high power density compared to other electrochemical energy carriers. In the present study, mixed hydroxide method is used to prepare Li[Ni 0.5 Co 0.25 Mn 0.25 ]O 2 from the precursors and analyze qualitatively and studied the electrochemical properties. The XRD spectrum exhibited predominant (003) orientation at 2θ =18.39 o corresponding to hexagonal layered structure of R3m symmetry with evaluated lattice parameters are a= 2.84 Å, c= 14.43 Å. Raman measurements were performed to understand the microstructure and vibrational modes of the prepared sample. From the electrochemical (EC) studies an initial discharge capacity of about 140 mAhg −1 with good cyclic stability was observed for the prepared sample in the potential range 0.0 −1.0V in aqueous medium

  6. The influence of ion implantation on the oxidation of nickel

    International Nuclear Information System (INIS)

    Goode, P.D.

    1975-11-01

    The effects of ion implantation on the oxidation of polycrystalline nickel have been studied for a range of implanted species: viz. He, Li, Ne, Ca, Ti, Ni, Co, Xe, Ce and Bi. The oxides were grown in dry oxygen at 630 0 C and the 16 O(d,p) 17 O nuclear reaction technique used to determine the amount of oxygen taken up. The influence of atomic and ionic size, valency and electronegativity of the implanted impurities was studied as also were the effects of ion bombardment damage and the influence of sputtering during implantation. Atomic size and the annealing of disorder were found to have a marked influence on oxide growth rate. The dependence of oxidation on annealing was further studied by implanting polycrystalline specimens with self ions and observing the oxide growth rate as a function of annealing temperature. A peak in the curve was found at 400 0 C and a similar peak observed at a somewhat higher temperature for oxidised single crystals. It is concluded that the oxidation rate will be influenced by those factors which alter the epitaxial relationship between metal and growing oxide. Such factors include atomic size of the implanted species, surface strain induced by implantation and changes in surface topography as a result of sputtering. In addition a model based on vacancy assisted cation migration is proposed to explain enhanced oxidation observed over a limited temperature range. (author)

  7. High-performance Electrochemical Energy Storage Electrodes Based on Nickel Oxide-coated Nickel Foam Prepared by Sparking Method

    International Nuclear Information System (INIS)

    Chuminjak, Yaowamarn; Daothong, Suphaporn; Kuntarug, Aekapong; Phokharatkul, Ditsayut; Horprathum, Mati; Wisitsoraat, Anurat; Tuantranont, Adisorn; Jakmunee, Jaroon; Singjai, Pisith

    2017-01-01

    Highlights: • NiO particles (3-10 nm) were sparked on Ni foams with varying times (45-180 min). • Larger NiO nanoparticles were aggregated to foam-like structure at a longer time. • The optimal time of 45 min led to a high specific capacity of 920 C/g at 1 A/g. • The specific capacity remained as high as 699 (76% of 920) C/g at 20 A/g. • The optimal electrode exhibited 96% capacity retention after 1000 cycles at 4 A/g. - Abstract: In this work, high-performance electrochemical energy storage electrodes were developed based on nickel oxide (NiO)-coated nickel (Ni) foams prepared by a sparking method. NiO nanoparticles deposited on Ni foams with varying sparking times from 45 to 180 min were structurally characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the electrochemical energy storage characteristics of the electrodes were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. It was found that NiO nanoparticles sparked on Ni foam with a longer time would be agglomerated and formed a foam-like network with large pore sizes and a lower surface area, leading to inferior charge storage behaviors. The NiO/Ni foam electrode prepared with the shortest sparking of 45 min displayed high specific capacities of 920 C g"-"1 (1840 F g"-"1) at 1 A g"-"1 and 699 (76% of 920) C g"-"1 at 20 A g"-"1 in a potential window of 0-0.5 V vs. Ag/AgCl as well as a good cycling performance with 96% capacity retention at 4 A g"-"1 after 1000 cycles and a low equivalent series resistance of 0.4 Ω. Therefore, NiO/Ni foam electrodes prepared by the sparking method are highly promising for high-capacity energy storage applications.

  8. Synthesis of p-type nickel oxide nanosheets on n-type titanium dioxide nanorod arrays for p-n heterojunction-based UV photosensor

    Science.gov (United States)

    Yusoff, M. M.; Mamat, M. H.; Malek, M. F.; Abdullah, M. A. R.; Ismail, A. S.; Saidi, S. A.; Mohamed, R.; Suriani, A. B.; Khusaimi, Z.; Rusop, M.

    2018-05-01

    Titanium dioxide (TiO2) nanorod arrays (TNAs) were synthesized and deposited on fluorine tin oxide (FTO)-coated glass substrate using a novel and facile immersion method in a glass container. The synthesis and deposition of p-type nickel oxide (NiO) nanosheets (NS) on the n-type TNAs was investigated in the p-n heterojunction photodiode (PD) for the application of ultraviolet (UV) photosensor. The fabricated TNAs/NiO NS based UV photosensor exhibited a highly increased photocurrent of 4.3 µA under UV radiation (365 nm, 750 µW/cm2) at 1.0 V reverse bias. In this study, the fabricated TNAs/NiO NS p-n heterojunction based photodiode showed potential applications for UV photosensor based on the stable photo-generated current attained under UV radiation.

  9. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available Nickel hydroxide films were prepared by electrodeposition from a solution Ni(NO32 0,05 mol L ?¹ on ITO electrodes (Tin oxide doped with Indium on PET-like plastic film, applying a current of - 0,1 A cm ?² during different time intervals between 1800 and 7200 s. The electrochemical behavior of the nickel hydroxide electrode was investigated through a cyclic voltammogram, in NaOH 1,0 mol L ?¹, where it was observed two peaks in the profile in 0,410 and 0,280 V, corresponding to redox couple Ni(II/Ni(III. A sensor for urea presenting a satisfactory answer can be obtained when, after the deposit of the film of Ni(OH2 on the electrode of nickel, it is immersed in a solution of NaOH 1,0 mol L ?¹ and applying a potential of + 0,435 V, where the maximum of the anodic current occurs in the cyclic voltammogram. Analyzing the results it can be observed that, for a range of analite concentration between 5 to 50 m mol L ?¹, the behavior is linear and the sensibility found was of 20,3 mA cm?² (mol L?¹?¹, presenting reproducibility confirming the nickel hydroxide electrodes utilization for the determination of urea.

  10. Structure of Ni-rich Ni--Cr--B--Si coating alloys

    International Nuclear Information System (INIS)

    Knotek, O.; Lugscheider, E.; Reimann, H.

    1975-01-01

    The structures of quaternary, nickel-rich Ni--Cr--B--Si alloys were analyzed at a constant boron content of 10 at. percent and a temperature of 850 0 C. The composition range for silicide formation was determined. In these quaternary alloys, known binary nickel silicides, nickel and chromium borides, and the ternary silico-boride Ni 6 Si 2 B were confirmed. A new composition for the W 5 Si 3 -type phase in the Ni--B--Si system was proposed. (U.S.)

  11. Effect of chemical treatment on the electrochemical properties of Li1.2NixMn0.8-xO2 (x = 0.2 and 0.25) in lithium-ion batteries

    Science.gov (United States)

    Konishi, Hiroaki; Hirano, Tatsumi; Takamatsu, Daiko; Gunji, Akira; Feng, Xiaoliang; Furutsuki, Sho; Okumura, Takefumi; Terada, Shohei

    2018-02-01

    The effect of chemical treatment using (NH4)2SO4 on the electrochemical properties of Li1.2Ni0.2Mn0.6O2 and Li1.2Ni0.25Mn0.55O2 was investigated. The treatment was effective in improving the Coulombic efficiency and discharge capacity of a Li1.2Ni0.2Mn0.6O2 cathode, but treatment with too much (NH4)2SO4 degraded the cathode's electrochemical performance. The effect of (NH4)2SO4 treatment on the charge-discharge reaction mechanism of Li1.2Ni0.2Mn0.6O2 was investigated by evaluating reaction potential, particle configuration, and oxidation state of transition metal. The experimental results indicated that the changes in the electrochemical performance of the treated cathodes were attributed to the changes in the surface state and of the element contributing to the redox reaction. Treatment with an appropriate amount of (NH4)2SO4 also improved the electrochemical performance of the high-nickel-content lithium-rich layer-structured cathode material Li1.2Ni0.25Mn0.55O2.

  12. Hydrothermally synthesized reduced graphene oxide/nickel hydroxide (rGO/Ni(OH)2) nanocomposite: A promising material in dye removal

    Science.gov (United States)

    Debata, Suryakanti; Das, Trupti R.; Madhuri, Rashmi; Sharma, Prashant K.

    2017-05-01

    In order to fulfill the unquenchable demand of this expanded human society, a large number of industries have grown up resulting in a severe pollution in air, soil and water as well. Industrial dye is one of the most abundant contaminant in fresh water. Here we have prepared reduced graphene oxide/nickel hydroxide nanocomposite (rGo/Ni(OH)2) by a facile hydrothermal method, aiming for the treatment of water disposed by the textile industries. The characteristic properties of the prepared sample was observed by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR). The effect of rGo/Ni(OH)2 on the adsorption of Rhodamine B (Rh-B) in aqueous solution was investigated, mainly focusing on the removal time. It was found that, at 45 min, the composite shows a complete disappearance of the initial concentration of Rhodamine B (RhB).

  13. A design strategy of large grain lithium-rich layered oxides for lithium-ion batteries cathode

    International Nuclear Information System (INIS)

    Jiang, Xiong; Wang, Zhenhua; Rooney, David; Zhang, Xiaoxue; Feng, Jie; Qiao, Jinshuo; Sun, Wang; Sun, Kening

    2015-01-01

    Highlights: • Ultrasound-assisted mixing lithium was used to synthesize Lithium-rich layered oxides. • Lithium-rich layered oxides composed of large grain had high capacity and high cycling stability. • This unique large grain overcomes stress-induced structural collapse caused by Li-ion insertion/extraction and reduces dissolution of Mn ions. • A new strategy of large grain could be employed to synthesize the other complex architectures for various applications. - Abstract: Li-rich materials are considered the most promising for Li-ion battery cathodes, as high capacity can be achieved. However, poor cycling stability is a critical drawback that leads to poor capacity retention. Here a strategy is used to synthesize a large-grain lithium-rich layered oxides to overcome this difficulty without sacrificing rate capability. This material is designed with micron scale grain with a width of about 300 nm and length of 1–3 μm. This unique structure has a better ability to overcome stress-induced structural collapse caused by Li-ion insertion/extraction and reduce the dissolution of Mn ions, which enable a reversible and stable capacity. As a result, this cathode material delivered a highest discharge capacity of around 308 mAh g −1 at a current density of 30 mA g −1 with retention of 88.3% (according to the highest discharge capacity) after 100 cycles, 190 mAh g −1 at a current density of 300 mA g −1 and almost no capacity fading after 100 cycles. Therefore, Lithium-rich material of large-grain structure is a promising cathode candidate in Lithium-ion batteries with high capacity and high cycle stability for application. This strategy of large grain may furthermore open the door to synthesize the other complex architectures for various applications

  14. Fabrication of Nickel Nanosized Powder from LiNiO2 from Spent Lithium-Ion Battery

    Directory of Open Access Journals (Sweden)

    Shun-Myung Shin

    2018-01-01

    Full Text Available In this study, a fabrication of nickel nanoparticles from LNO(LiNiO2, which is a cathode active material, was synthesized by the liquid reduction process of NiSO4, obtained through a leaching and purification process. Hydrazine monohydrate (N2H4·H2O was used as a liquid reducing agent and it was added to NiSO4 at a volume ratio of NiSO4:N2H4·H2O = 10:3 and reacted for 10 min to synthesize the nickel hydrazine complex. Sodium hydroxide was added to the nickel hydrazine complex at the weight ratio of NiSO4:NaOH = 10:1.25–1.5 and the reduction reaction was performed at 80 °C for 15 min to synthesize nickel particles. Synthesized nickel particles were agglomerated and had a mean size of 200 nm to 300 nm. Ultrasonic dispersion, which is a physical dispersion method, was conducted. The nickel had particles of 100 nm or less when dispersed for 2 h at an ultrasonic intensity of 40 kHz. In order to prevent the agglomeration of the dispersed particles again, polyvinylpyrrolidone (PVP, an interfacial stabilizer, was added to stabilize the dispersed particles. It was confirmed that the nanoparticles were stably retained when PVP was added in an amount of 1 to 2 wt % based on the weight of the nickel. The purity of nickel recovered was found to be 99.62 wt %.

  15. Mechanism for the effect of sulphate on SCC in BWRs. Part 1: Hypothesis; Part 2: Microstructural examination of an oxide layer on steel

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Gott, K.; Vatter, I.; Crossley, A.; Cattle, G.

    1999-07-01

    Part 1: Stress corrosion cracking is one of the most serious materials related problems encountered in BWRs. The crack propagation rate has been shown to be strongly affected by sulphates in the coolant. Typical concentrations of sulphates and other anions in the primary water is 1 ppb. The values can increase temporarily to much higher values during transients. Shorter periods of such extra exposure give no effect, but there seems to be an integrated threshold value ('Memory effect') beyond which the propagation rate increases rapidly. The primary system surfaces communicating with the bulk water are normally protected by a very thin, passivating oxide film. This is composed of spinel phases like chromite, situated closest to the metal upon which there could be a layer of nickel ferrite. On top of the spinels there is also normally a cover of deposits. This composite film is going to act as a surface for adsorption, transportation and storage of sulphates from the primary bulk water. Starting from a comparison of the surface conditions around a corrosion pit it was proposed that in the close vicinity of an active crack, the surface oxide is going to function as a cathode on which pH and also the potential are high compared to the surrounding surfaces. The permeability of the oxide is essential for the cathodic function as chemical species and charge have to be transported through it. This has led to the hypothesis that the rate determining step of the crack propagation should be found in the set of processes on the cathode like adsorption, transportation, chemical transformation and precipitation in which hydrogen sulphate and sulphate participate while migrating through the cathodic area towards the crack. It is also postulated that the permeability and geometry of the cathodic surface oxide will be influenced by sulphate and other sulphur containing species breaking down the passive film. Sulphate entering the crack environment can be reduced down to sulphide

  16. NICKEL PLATING PROCESS

    Science.gov (United States)

    Hoover, T.B.; Zava, T.E.

    1959-05-12

    A simplified process is presented for plating nickel by the vapor decomposition of nickel carbonyl. In a preferred form of the invention a solid surface is nickel plated by subjecting the surface to contact with a mixture containing by volume approximately 20% nickel carbonyl vapor, 2% hydrogen sulfide and .l% water vapor or 1% oxygen and the remainder carbon dioxide at room temperature until the desired thickness of nickel is obtained. The advantage of this composition over others is that the normally explosive nickel carbonyl is greatly stabilized.

  17. Disposable Non-Enzymatic Glucose Sensors Using Screen-Printed Nickel/Carbon Composites on Indium Tin Oxide Electrodes.

    Science.gov (United States)

    Jeon, Won-Yong; Choi, Young-Bong; Kim, Hyug-Han

    2015-12-10

    Disposable screen-printed nickel/carbon composites on ind