Theoretical study on the correlation between the nature of atomic Li intercalation and electrochemical reactivity in TiS2 and TiO2.

Science.gov (United States)

Kim, Yang-Soo; Kim, Hee-Jin; Jeon, Young-A; Kang, Yong-Mook

2009-02-12

The electronic structures of LiTiS(2) and LiTiO(2) (having alpha-NaFeO(2) structure) have been investigated using discrete variational Xalpha molecular orbital methods. The alpha-NaFeO(2) structure is the equilibrium structure for LiCoO(2), which is widely used as a commercial cathode material for lithium secondary batteries. This study especially focused on the charge state of Li ions and the magnitude of covalency around Li ions. When the average voltage of lithium intercalation was calculated using pseudopotential methods, the average intercalation voltage of LiTiO(2) (2.076 V) was higher than that of LiTiS(2) (1.958 V). This can be explained by the differences in Mulliken charge of lithium and the bond overlap population between the intercalated Li ions and anion in LiTiO(2) as well as LiTiS(2). The Mulliken charge, which is the ionicity of Li atom, was approximately 0.12 in LiTiS(2), and the bond overlap population (BOP) indicating the covalency between Ti and S was about 0.339. When compared with the BOP (0.6) of C-H, which is one of the most famous example of covalent bonding, the intercalated Li ions in LiTiS(2) tend to form a quite strong covalent bond with the host material. In contrast, the Mulliken charge of lithium was about 0.79, which means that Li is fully ionized and the BOP, the covalency between Ti and O, was 0.181 in LiTiO(2). Because of the high ionicity of Li and the weak covalency between Ti and the nearest anion, LiTiO(2) has a higher intercalation voltage than LiTiS(2).

Li{sub 4}SiO{sub 4} based breeder ceramics with Li{sub 2}TiO{sub 3}, LiAlO{sub 2} and Li{sub X}La{sub Y}TiO{sub 3} additions, part II: Pebble properties

Energy Technology Data Exchange (ETDEWEB)

Kolb, M.H.H., E-mail: Matthias.kolb@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, PO Box 3640, 76021, Karlsruhe (Germany); Knitter, R. [Karlsruhe Institute of Technology, Institute for Applied Materials, PO Box 3640, 76021, Karlsruhe (Germany); Hoshino, T. [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Fusion Energy Research and Development Directorate, National Institutes for Quantum and Radiological Science and Technology (QST) (Japan)

2017-02-15

Highlights: • The mechanical strength of Li{sub 4}SiO{sub 4}-based breeder pebbles can be improved by adding either LMT, LAO or LLTO as second phase. • The increase in strength is closely linked to a reduction of the open porosity of the pebbles. • All fabricated pebbles show a highly homogenous microstructure with mostly low closed porosity. • Adding LLTO, although it decomposes during sintering, greatly improves the strength of the pebbles. - Abstract: The pebble properties of novel two-phase Li{sub 4}SiO{sub 4} pebbles of 1 mm diameter with additions of Li{sub 2}TiO{sub 3}, LiAlO{sub 2} or Li{sub x}La{sub y}TiO{sub 3} are evaluated in this work as a function of the second phase concentration and the microstructure of the pebbles. The characterization focused on the mechanical strength, microstructure and open as well as closed porosity. Therefore crush load tests, SEM analyses as well as helium pycnometry and optical image analysis were performed, respectively. This work shows that generally additions of a second phase to Li{sub 4}SiO{sub 4} considerably improve the mechanical strength. It also shows that the fabrication processes have to be well-controlled to achieve high mechanical strengths. When Li{sub 2}TiO{sub 3} is added in different concentrations, the determinant for the crush load seems to be the open porosity of the pebbles. The strengthening effect of LiAlO{sub 2} compared to Li{sub 2}TiO{sub 3} is similar, while additions of Li{sub x}La{sub y}TiO{sub 3} increase the mechanical strength much more. Yet, Li{sub 4}SiO{sub 4} and Li{sub x}La{sub y}TiO{sub 3} react with each other to a number of different phases upon sintering. In general the pebble properties of all samples are favorable for use within a fusion breeder blanket.

Improved electrochemical properties of Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} composite anodes prepared by a solid-state synthesis

Energy Technology Data Exchange (ETDEWEB)

Zhu, Yan-Rong; Yuan, Jing; Zhu, Min [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, Anhui 243002 (China); Hao, Guodong [College of Chemistry and Chemical Engineering, Mudanjiang Normal University, Mudanjiang, Heilongjiang 157012 (China); Yi, Ting-Feng, E-mail: tfyihit@163.com [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, Anhui 243002 (China); Xie, Ying, E-mail: xieying@hlju.edu.cn [Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials Science, Heilongjiang University, Harbin, Heilongjiang 150080 (China)

2015-10-15

Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} composite anodes are successfully prepared by a facile solid state route. The structure, morphology and electrochemical performance of all samples are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and charge–discharge tests, respectively. XRD reveals that the little La{sup 3+} ions enter into the lattice, and then make the crystal lattice of Li{sub 4}Ti{sub 5}O{sub 12} expand. SEM shows that all samples are composed of 1–2 μm primary particles with irregular shapes. CV and EIS imply that Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} composites have lower polarization, larger lithium-ion diffusion coefficient and smaller charge transfer resistance corresponding to a much higher conductivity than those of Li{sub 4}Ti{sub 5}O{sub 12} corresponding to the extraction of Li{sup +} ions. The improved electrochemical performance of Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} composites can be attributed to the enhanced transfer kinetics of both the lithium ions and electrons. Particularly, Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} (5 wt.%) composite shows a excellent high-rate capability and cycling stability. Therefore, the present Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} (5 wt.%) composite anode is capable of large-scale applications, such as electric vehicles and hybrid electric vehicles, requiring high energy, long life and excellent safety. - Highlights: • The electrochemical property of Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} down to 0 V is first reported. • Li{sub 0.33}La{sub 0.56}TiO{sub 3} modifying results in fast lithium insertion/extraction kinetics. • Li{sub 4}Ti{sub 5}O{sub 12}–Li{sub 0.33}La{sub 0.56}TiO{sub 3} (5 wt.%) exhibits a good fast charge

Hybrid microwave synthesis and characterization of the compounds in the Li-Ti-O system

Energy Technology Data Exchange (ETDEWEB)

Yang, Li Hong; Dong, Cheng; Guo, Juan [National Laboratory for Superconductivity, Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Science, P.O. Box 603, Beijing 100080 (China)

2008-01-03

Hybrid microwave synthesis has been applied for preparation of Li{sub 4}Ti{sub 5}O{sub 12}, Li{sub 2}Ti{sub 3}O{sub 7}, Li{sub 2}TiO{sub 3} and LiTiO{sub 2} for the first time. Stepwise heating was used for avoiding the instantaneous release of gas by-product and obtaining well-shaped samples. The samples were characterized by powder X-ray diffraction, energy-dispersive X-ray analysis and scanning electron microscopy. The obtained samples have relatively uniform particle sizes. The electrochemical performance of Li{sub 4}Ti{sub 5}O{sub 12} and Li{sub 2}Ti{sub 3}O{sub 7} were investigated. The first discharge capacity of Li{sub 4}Ti{sub 5}O{sub 12} was 150 mAh g{sup -1} and 141 mAh g{sup -1} after 27 cycles and a very flat discharge and charge curve of Li{sub 4}Ti{sub 5}O{sub 12} was shown at about 1.56 V. Similarly, Li{sub 2}Ti{sub 3}O{sub 7} exhibits good cycle performance. The initial discharge capacity is 118 mAh g{sup -1} and 30th cycle is still 112 mAh g{sup -1}. (author)

Facile Solution Route to Synthesize Nanostructure Li4Ti5O12 for High Rate Li-Ion Battery

Directory of Open Access Journals (Sweden)

M. V. Tran

2016-01-01

Full Text Available High rate Li-ion batteries have been given great attention during the last decade as a power source for hybrid electric vehicles (HEVs, EVs, etc. due to the highest energy and power density. These lithium batteries required a new design of material structure as well as innovative electrode materials. Among the promising candidates, spinel Li4Ti5O12 has been proposed as a high rate anode to replace graphite anode because of high capacity and a negligible structure change during intercalation of lithium. In this work, we synthesized a spinel Li4Ti5O12 in nanosize by a solution route using LiOH and Ti(OBu4 as precursor. An evaluation of structure and morphology by XRD and SEM exhibited pure spinel phase Li4Ti5O12 and homogenous nanoparticles around 100 nm. In the charge-discharge test, nanospinel Li4Ti5O12 presents excellent discharge capacity 160 mAh/g at rate C/10, as well as good specific capacities of 120, 110, and 100 mAh/g at high rates C, 5C and 10C, respectively.

Lithium ion diffusion in Li4+xTi5O12: From ab initio studies

International Nuclear Information System (INIS)

Chen, Y.C.; Ouyang, C.Y.; Song, L.J.; Sun, Z.L.

2011-01-01

Highlights: → Li diffusion pathways in Li 4 Ti 5 O 12 and Li 7 Ti 5 O 12 are obtained from ab initio calculations. → Cooperative Li migration in Li 7+δ Ti 5 O 12 with very low energy barrier is proposed. → Li diffusion is faster in lithiated state than in delithiated state is confirmed theoretically. - Abstract: Lithium ion dynamics in Li 4+x Ti 5 O 12 spinel are investigated from first principles calculations. The diffusion pathways are optimized and the energy barriers of lithium migration under four types of dilute defect extremes: Li 4+δ Ti 5 O 12 , Li 4-δ Ti 5 O 12 , Li 7+δ Ti 5 O 12 and Li 7-δ Ti 5 O 12 (δ << 1) are calculated with the nudged elastic band method. Results show that lithium diffusion in the charged state (energy barriers are 1.0 and 0.7 eV for interstitial Li and Li vacancy diffusion, respectively) is much slower than in the discharged state (energy barriers are 0.13 and 0.35 eV for interstitial Li and Li vacancy diffusion, respectively). The diffusion coefficients are evaluated based on lattice gas model and hopping mechanism. The obtained results are compared with available experimental data within a two-phase co-existence framework.

Li{sub 4}SiO{sub 4} based breeder ceramics with Li{sub 2}TiO{sub 3}, LiAlO{sub 2} and Li{sub X}La{sub Y}TiO{sub 3} additions, part I: Fabrication

Energy Technology Data Exchange (ETDEWEB)

Kolb, M.H.H., E-mail: Matthias.kolb@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, PO Box 3640, 76021 Karlsruhe (Germany); Mukai, K.; Knitter, R. [Karlsruhe Institute of Technology, Institute for Applied Materials, PO Box 3640, 76021 Karlsruhe (Germany); Hoshino, T. [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Fusion Energy Research and Development Directorate, National Institutes for Quantum and Radiological Science and Technology (QST) (Japan)

2017-02-15

Highlights: • This study shows that the emulsion method can easily be adapted to add different phases into Li4SiO4 breeder pebbles. • Slurries with various compositions to form LOS + LMT, LOS + LAO and LOS + LLTO were processed.The calculated activation behavior shows that samples with added LAO or LLTO qualify as low activation material. • Yet, the long-term activation of the LAO containing samples is problematic as hands-on level activity is not reached quickly. - Abstract: Wet-chemical fabrication processes are highly adaptable to a wide range of raw materials and are therefore well suited for evaluating new material compositions. Here the established emulsion method was modified to fabricate novel two-phase Li{sub 4}SiO{sub 4} pebbles of 1 mm diameter with additions of Li{sub 2}TiO{sub 3}, LiAlO{sub 2} or Li{sub x}La{sub y}TiO{sub 3}. As the lithium density of the latter two compounds is relatively low, only moderate contents were added. The Li{sub 2}TiO{sub 3} additions, however, cover the full compositional range. The fabrication process was characterized with regard to its constancy and aptness for the anticipated pebble compositions by optical pebble size measurements. Also the phase content and the elemental composition of the fabricated pebbles were analyzed by XRD and ICP-OES combined with XRF, respectively. This work shows that the emulsion method is an appropriate method to produce pebbles with the anticipated Li{sub 2}TiO{sub 3} and LiAlO{sub 2} concentrations in a Li{sub 4}SiO{sub 4} matrix. However, Li{sub 4}SiO{sub 4} and Li{sub x}La{sub y}TiO{sub 3} react with each other to a number of different phases. To evaluate the activation properties of the pebbles, FISPACT calculations with a DEMO relevant neutron source are applied as well. The addition of aluminum seems to be unfavorable for a fusion application, but moderate concentrations of lanthanum can be tolerated.

Tritium trapping states induced by lithium-depletion in Li{sub 2}TiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Makoto, E-mail: kobayashi.makoto@LHD.nifs.ac.jp [National Institute for Fusion Science (Japan); Oya, Yasuhisa; Okuno, Kenji [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan)

2017-04-15

Identifications of tritium trapping states in neutron-irradiated Li{sub 1.8}TiO{sub 2.9} (lithium-depleted Li{sub 2}TiO{sub 3}) were carried out by the out-of-pile tritium release behavior. Tritium release behaviors for neutron-irradiated Li{sub 2}TiO{sub 3} and tritium gas-exposed TiO{sub 2} were also measured for comparison. Among the tritium release spectra for these samples, three tritium release peaks were appeared. By the kinetic analyses of tritium release behaviors, the Arrhenius parameters for three peaks were evaluated. Especially for Li{sub 1.8}TiO{sub 2.9}, there were two tritium release peaks, and the peak in lower temperature region was assigned to the tritium release controlled by the diffusion process in Li{sub 2}TiO{sub 3} structure. The other tritium release peak, which was hardly appeared for Li{sub 2}TiO{sub 3}, was assigned to the release of tritium trapped as hydroxyl groups in Li{sub 1.8}TiO{sub 2.9}, indicating that lithium-depletion would result in the formation of hydroxyl groups in Li{sub 2}TiO{sub 3}. Lithium vacancies existed in Li{sub 2}TiO{sub 3} crystal structure would promote the tritium trapping as hydroxyl groups due to the decreased charge repulsion between lithium ions and tritium ion, resulting in the difficulty of recovering tritium from Li{sub 2}TiO{sub 3} effectively.

Kinetic analysis of the thermal decomposition of Li4Ti5O12 pellets

Directory of Open Access Journals (Sweden)

Hugo A. Mosqueda

2011-12-01

Full Text Available A single dynamic kinetic analysis, describing the surface decomposition of Li4Ti5O12 pellets, has been performed. Samples were analyzed by X-ray diffraction and scanning electron microscopy. The analyses were performed between 1000 and 1100°C and different times, perceiving the Li4Ti5O12 decomposition to Li2Ti3O7, with a loss of lithium. As expected, more rapid decomposition behaviour was found at higher temperatures. Finally, the activation energy for this decomposition of Li4Ti5O12 to Li2Ti3O7 was estimated to be equal to 383 kJ/mol.

Synthesis and characterization of LiF: Mg, Ti for ionizing radiations dosimetry

International Nuclear Information System (INIS)

Lozano R, I. B.

2011-01-01

Among the different thermoluminescence materials (Tl), the LiF:Mg, Ti is the most used for dosimetric purposes, because its equivalence to the human tissue, it has an effective atomic number of 8.14, the best known commercial dosemeter of this kind is the TLD-100. However, because this dosimeter is an imported product, is quite expensive for many research groups and hospitals. The purpose of this work is the optimization of its synthesis, as the dosimetric characterization, so it can replace the imported dosimeters. The synthesis of LiF:Mg, Ti is a careful process, since one of the reagents, the ion fluorine is highly corrosive. In this work the synthesis of the LiF:Mg, Ti was done by the molten substance method, was used LiF of analytical grade and the magnesium (Mg) and titanium (Ti) activators were incorporated in aqueous solution. For to optimize the handle of the material Tl, we elaborated pellets and teflon (Ptfe) was used as agglutinate material, in a 2:3 proportion. First was prepared the LiF, incorporating just Mg as dopant with a concentration of 400 parts per million (ppm). After the Ti with concentrations from 15 to 120 ppm was incorporated keeping fixed the concentration of Mg (400 ppm). The morphological and structural characterization of the Tl material were made by scanning electron microscopy and X-ray diffraction. The optimal concentration of Ti, was determined as a function of the radiation dose sensibility of the Tl material. The material prepared with 60 ppm of the Ti showed a higher sensibility. However, also the rest of the preparations had the requirements recommended by the international agencies to be used in ionizing radiations dosimetry. For the dosimetric characterization were used samples with 400 ppm of Mg, 400 ppm Mg and 30 ppm Ti, 400 ppm Mg and 60 ppm Ti. The LiF:Mg showed its dosimetric peak at 240 C, while the LiF:Mg, Ti (30 ppm and 60 ppm Ti) showed their dosimetric peak at 220 C and 222 C respectively. The study of the Tl

High-Rate and Long-Term Cycle Stability of Li-S Batteries Enabled by Li2S/TiO2-Impregnated Hollow Carbon Nanofiber Cathodes.

Science.gov (United States)

Wang, Xinran; Bi, Xuanxuan; Wang, Shaona; Zhang, Yi; Du, Hao; Lu, Jun

2018-05-16

The high theoretical energy density of lithium-sulfur (Li-S) batteries makes them an alternative battery technology to lithium ion batteries. However, Li-S batteries suffer from low sulfur loading, poor charge transport, and dissolution of lithium polysulfide. In our study, we use the lithiated S, Li 2 S, as the cathode material, coupled with electrospun TiO 2 -impregnated hollow carbon nanofibers (TiO 2 -HCFs), which serve as the conductive agent and protective barrier for Li 2 S in Li-S batteries. TiO 2 -HCFs provide much improved electron/ionic conductivity and serve as a physical barrier, which prevents the dissolution of lithium polysulfides. The Li 2 S/TiO 2 -HCF composite delivers a discharge capacity of 851 mA h g Li 2 S -1 at 0.1C and the bilayer TiO 2 -HCFs/Li 2 S/TiO 2 -HCF composite delivers a high specific capacity of 400 mA h g Li 2 S -1 at 5C.

Synthesis of the lithium metatitanate, Li2TiO3, by the modified combustion method

International Nuclear Information System (INIS)

Cruz, D.; Bulbulian, S.; Pfeiffer, H.

2005-01-01

A modified combustion method to obtain Li 2 TiO 3 it was used, a compound to be used in fusion reactors like tritium generator material. To obtain Li 2 TiO 3 were proven different molar ratios of lithium hydroxide (LiOH), titanium oxide (TiO 2 ) and urea (CO(NH 2 ) 2 ), as well as different heating temperatures (550, 650 and 750 C). The characterization of the products it was carried out using X-ray diffraction, Scanning electron microscopy and Thermal gravimetric analysis. The sample prepared with a molar ratio Li: Ti: urea = 2.75: 1: 3 was the one that presented as only product the Li 2 TiO 3 . The particle size and the morphology found in the Li 2 TiO 3 , showed similar particle size and morphology to the TiO 2 used as precursor. (Author)

Density functional theory studies of TiO2 for photocatalysis and Li storage applications

Science.gov (United States)

Kim, Yong-Hoon; Lee, Ji Il; Lee, Dong Ki; Lee, Gyu Heon; Kang, Jeung Ku

We present two theory-experiment collaboration studies of anatase TiO2 for energy applications. First, we discuss a hydrogen-nitrogen co-doped TiO2 (HN-TiO2) as a photocatalyst, and show that the interstitially introduced HN contributes to the increase of solar-to-fuel conversion efficiency. We find that the variation of valence band maximum (VBM) of NH-TiO2 extends the photoactive spectrum to the visible light, and argue that created mid-gap states produce efficient electron and hole conduction channels. Next, we consider experimentally fabricated hierarchical TiO2 nanocrystals integrated with binder-free porous graphene (PG) network foam for a Li storage application. It was found that the TiO2-PG facilitated rapid ionic transfer during the Li-ion insertion/extraction process. We clarify the mechanisms by showing that Li ion migration into the TiO2-PG interface stabilize the binder-free oxide-graphene interface. Atomistic mechanism of Li ion insertion and migration is discussed by comparing cases between an isolated Li ion, when the crowding effect is included, and when the surface Li ions are present. We found that the supply of additional surface Li ions significantly reduce the Li insertion barrier, driving a spontaneous domino-like concerted Li insertion at the oxide surface region.

Rapid charge-discharge property of Li4Ti5O12-TiO2 nanosheet and nanotube composites as anode material for power lithium-ion batteries.

Science.gov (United States)

Yi, Ting-Feng; Fang, Zi-Kui; Xie, Ying; Zhu, Yan-Rong; Yang, Shuang-Yuan

2014-11-26

Well-defined Li4Ti5O12-TiO2 nanosheet and nanotube composites have been synthesized by a solvothermal process. The combination of in situ generated rutile-TiO2 in Li4Ti5O12 nanosheets or nanotubes is favorable for reducing the electrode polarization, and Li4Ti5O12-TiO2 nanocomposites show faster lithium insertion/extraction kinetics than that of pristine Li4Ti5O12 during cycling. Li4Ti5O12-TiO2 electrodes also display lower charge-transfer resistance and higher lithium diffusion coefficients than pristine Li4Ti5O12. Therefore, Li4Ti5O12-TiO2 electrodes display lower charge-transfer resistance and higher lithium diffusion coefficients. This reveals that the in situ TiO2 modification improves the electronic conductivity and electrochemical activity of the electrode in the local environment, resulting in its relatively higher capacity at high charge-discharge rate. Li4Ti5O12-TiO2 nanocomposite with a Li/Ti ratio of 3.8:5 exhibits the lowest charge-transfer resistance and the highest lithium diffusion coefficient among all samples, and it shows a much improved rate capability and specific capacity in comparison with pristine Li4Ti5O12 when charging and discharging at a 10 C rate. The improved high-rate capability, cycling stability, and fast charge-discharge performance of Li4Ti5O12-TiO2 nanocomposites can be ascribed to the improvement of electrochemical reversibility, lithium ion diffusion, and conductivity by in situ TiO2 modification.

Enhanced cycling stability of microsized LiCoO2 cathode by Li4Ti5O12 coating for lithium ion battery

International Nuclear Information System (INIS)

Yi, Ting-Feng; Shu, J.; Yue, Cai-Bo; Zhu, Xiao-Dong; Zhou, An-Na; Zhu, Yan-Rong; Zhu, Rong-Sun

2010-01-01

The effect of Li 4 Ti 5 O 12 (LTO) coating amount on the electrochemical cycling behavior of the LiCoO 2 cathode was investigated at the high upper voltage limit of 4.5 V. Li 4 Ti 5 O 12 (≤5 wt.%) is not incorporated into the host structure and leads to formation of uniform coating. The cycling performance of LiCoO 2 cathode is related with the amount of Li 4 Ti 5 O 12 coating. The initial capacity of the LTO-coated LiCoO 2 decreased with increasing Li 4 Ti 5 O 12 coating amount but showed enhanced cycling properties, compared to those of pristine material. The 3 wt.% LTO-coated LiCoO 2 has the best electrochemical performance, showing capacity retention of 97.3% between 2.5 V and 4.3 V and 85.1% between 2.5 V and 4.5 V after 40 cycles. The coulomb efficiency shows that the surface coating of Li 4 Ti 5 O 12 is beneficial to the reversible intercalation/de-intercalation of Li + . LTO-coated LiCoO 2 provides good prospects for practical application of lithium secondary batteries free from safety issues.

Anatase-TiO{sub 2} nanocoating of Li{sub 4}Ti{sub 5}O{sub 12} nanorod anode for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Chen, Ming-ming, E-mail: chmm@tju.edu.cn; Sun, Xin; Qiao, Zhi-jun; Ma, Qian-qian; Wang, Cheng-yang

2014-07-15

Highlights: • TiO{sub 2}-coated LTO was in-situ prepared via a microemulsion-assisted hydrothermal route. • Anatase-TiO{sub 2} coating layer enhances the electrochemical performance of Li{sub 4}Ti{sub 5}O{sub 12}. • The as-prepared sample presents high-rate capability and cyclic stability. - Abstract: Li{sub 4}Ti{sub 5}O{sub 12} nanorod coated by anatase-TiO{sub 2} is in situ synthesized via a microemulsion-assisted hydrothermal method followed by heat treatment at 550 °C in air. Compared with pure Li{sub 4}Ti{sub 5}O{sub 12}, Li{sub 4}Ti{sub 5}O{sub 12} nanorod coated by anatase-TiO{sub 2} presents much improved electrochemical characteristics in terms of high specific capacity, excellent rate capability and cyclic stability (96.0% of initial capacity at a current density of 1.75 A g{sup −1} up to 100 cycles). Acting as a perfect nanocoating layer, anatase-TiO{sub 2} contributes some capacity and gives an enhanced performance to the Li{sub 4}Ti{sub 5}O{sub 12} electrode. All the results suggest that Li{sub 4}Ti{sub 5}O{sub 12} nanorod coated by anatase-TiO{sub 2} could be suitable for use as a high-rate anode material for lithium-ion batteries.

Li depletion effects on Li2TiO3 reaction with H2 in thermo-chemical environment relevant to breeding blanket for fusion power plants

International Nuclear Information System (INIS)

Alvani, Carlo; Casadio, Sergio; Contini, Vittoria; Giorgi, Rossella; Mancini, Maria Rita; Tsuchiya, Kunihiko; Kawamura, Hiroshi

2005-07-01

This is a report of the Working Group in the Subtask on Solid Breeder Blankets under the Implementing Agreement on a Co-operative Programme on Nuclear Technology of Fusion Reactors (International Energy Agency (IEA)). This Working Group (Task F and WG-F) was performed from 2000 to 2004 by a collaboration of European Union (EU) and Japan (JA). In this report, lithium depletion effects on the reaction of lithium titanate (Li 2 TiO 3 ) with hydrogen (H 2 ) in thermo-chemical environment were discussed. The reaction of Li 2 TiO 3 ceramics with H 2 was studied in a thermo-chemical environment simulating (excepting irradiation) that of the hottest pebble-bed zone of breeding-blanket actually designed for fusion power plants. This 'reduction' as performed at 900degC in Ar+0.1%H, purge gas (He+0.1%H 2 being the designed reference') was found to be enhanced by TiO 2 doping of the specimens of simulate 6 Li-burn-up expected to reach 20% at their end-of-life. The reaction rates, however, were so slow to be not significantly extrapolated to the breeder material service time (years). In Ar+3%H 2 , faster reaction rates allowed a better identification of the process evolution (kinetics) by Temperature-Programmed Reduction' (TPR) and 'Oxidation' (TPO), and combined TG-DTA thermal analysis. The reduction of pure Li 4/5 TiO 12/5 spinel phase to Li 4/5 TiO 12/5-y was found to reach in one day the steady state at the O-vacancy concentration y=0.2. Complimentary microscopy (SEM) and spectroscopy (XRD, XPS) techniques were used to characterize the reaction products among which the presence of the orthorhombic Li v TiO 2 (0 ≤ v ≤ 1/2) and Li 2 TiO 3 could be diagnosed. So that the complete spinel reduction to Li 1/2 TiO 2 was obtained according to a scheme involving the Li 1/2 TiO 2 -Li 4/5 TiO 12/5 spinel phase solid solution for which y=3v/(10-5v). The reduction rate of pure meta-titanate to Li 2 TiO 3-x was found much lower (x approx. = 0.01) and even possibly due to the presence

Facile Synthesis of Carbon-Coated Spinel Li4Ti5O12/Rutile-TiO2 Composites as an Improved Anode Material in Full Lithium-Ion Batteries with LiFePO4@N-Doped Carbon Cathode.

Science.gov (United States)

Wang, Ping; Zhang, Geng; Cheng, Jian; You, Ya; Li, Yong-Ke; Ding, Cong; Gu, Jiang-Jiang; Zheng, Xin-Sheng; Zhang, Chao-Feng; Cao, Fei-Fei

2017-02-22

The spinel Li 4 Ti 5 O 12 /rutile-TiO 2 @carbon (LTO-RTO@C) composites were fabricated via a hydrothermal method combined with calcination treatment employing glucose as carbon source. The carbon coating layer and the in situ formed rutile-TiO 2 can effectively enhance the electric conductivity and provide quick Li + diffusion pathways for Li 4 Ti 5 O 12 . When used as an anode material for lithium-ion batteries, the rate capability and cycling stability of LTO-RTO@C composites were improved in comparison with those of pure Li 4 Ti 5 O 12 or Li 4 Ti 5 O 12 /rutile-TiO 2 . Moreover, the potential of approximately 1.8 V rechargeable full lithium-ion batteries has been achieved by utilizing an LTO-RTO@C anode and a LiFePO 4 @N-doped carbon cathode.

Optical and paramagnetic properties of Ti in LiF

International Nuclear Information System (INIS)

Krystek, M.

1982-01-01

Titanium replaces substitutionally Li + at its lattice site in LiF. The resulting deep impurity must be understood as TiF 6 -cluster. The symmetry of this cluster is octahedral in the case of the unoccupied impurity. If the impurity will be occupied by an electron, a trigonal distortion of the cluster results, whereby the orbital degeneracy of the ground state will be liftet. Since the occupied impurity is paramagnetic, the symmetry reduction could be proved by ENDOR measurements. Using a calculated term diagram of the impurity inside the crystal a model is offered to explain the photoluminescence and the thermoluminescence of LiF:Ti. (orig./HP) [de

Synthesis of the lithium metatitanate, Li{sub 2}TiO{sub 3}, by the modified combustion method; Sintesis del metatitanato de litio, Li{sub 2}TiO{sub 3}, por el metodo modificado de combustion

Energy Technology Data Exchange (ETDEWEB)

Cruz, D.; Bulbulian, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Pfeiffer, H. [IIM-UNAM, A.P. 70-360, 04510 Mexico D.F. (Mexico)]. e-mail: sb@nuclear.inin.mx

2005-07-01

A modified combustion method to obtain Li{sub 2}TiO{sub 3} it was used, a compound to be used in fusion reactors like tritium generator material. To obtain Li{sub 2}TiO{sub 3} were proven different molar ratios of lithium hydroxide (LiOH), titanium oxide (TiO{sub 2}) and urea (CO(NH{sub 2}){sub 2}), as well as different heating temperatures (550, 650 and 750 C). The characterization of the products it was carried out using X-ray diffraction, Scanning electron microscopy and Thermal gravimetric analysis. The sample prepared with a molar ratio Li: Ti: urea = 2.75: 1: 3 was the one that presented as only product the Li{sub 2}TiO{sub 3}. The particle size and the morphology found in the Li{sub 2}TiO{sub 3}, showed similar particle size and morphology to the TiO{sub 2} used as precursor. (Author)

Fabrication of Li_2TiO_3 pebbles by a selective laser sintering process

International Nuclear Information System (INIS)

Zhou, Qilai; Gao, Yue; Liu, Kai; Xue, Lihong; Yan, Youwei

2015-01-01

Highlights: • Selective laser sintering (SLS) is employed to fabricate ceramic pebbles. • Quantities and diameter of the pebbles could be easily controlled by adjusting the model of pebbles. • All the pebbles could be prepared at a time within several minutes. • The Li_2TiO_3 pebbles sintered at 1100 °C show a notable crush load of 43 N. - Abstract: Lithium titanate, Li_2TiO_3, is an important tritium breeding material for deuterium (D)–tritium (T) fusion reactor. In test blanket module (TBM) design of China, Li_2TiO_3 is considered as one candidate material of tritium breeders. In this study, selective laser sintering (SLS) technology was introduced to fabricate Li_2TiO_3 ceramic pebbles. This fabrication process is computer assisted and has a high level of flexibility. Li_2TiO_3 powder with a particle size of 1–3 μm was used as the raw material, whilst epoxy resin E06 was adopted as a binder. Green Li_2TiO_3 pebbles with certain strengths were successfully prepared via SLS. Density of the green pebbles was subsequently increased by cold isostatic pressing (CIP) process. Li_2TiO_3 pebbles with a diameter of about 2 mm were obtained after high temperature sintering. Density of the pebbles reaches 80% of theoretical density (TD) with a comparable crush load of 43 N. This computer assisted approach provides a new efficient route for the production of Li_2TiO_3 ceramic pebbles.

Studies of the effects of TiCl3 in LiBH4/CaH2/TiCl3 reversible hydrogen storage system

International Nuclear Information System (INIS)

Liu Dongan; Yang Jun; Ni Jun; Drews, Andy

2012-01-01

Highlights: ► We systematically studied the effects of TiCl 3 in LiBH 4 /CaH 2 /TiCl 3 hydrogen storage system. ► It is found that adding 0.25 TiCl 3 produces fully reversible hydrogen absorption and desorption and a lower desorption temperature. ► LiCl experiences four different states, i.e. “formed-solid solution-molten solution-precipitation”, in the whole desorption process of the system. ► The incorporation of LiCl into LiBH 4 forms more viscous molten LiBH 4 ·LiCl, leading to fast kinetics. ► The precipitation and re-incorporation of LiCl into LiBH 4 lead to a fully reversible complex hydrogen storage system. - Abstract: In the present study, the effects of TiCl 3 on desorption kinetics, absorption/desorption reversibility, and related phase transformation processes in LiBH 4 /CaH 2 /TiCl 3 hydrogen storage system was studied systematically by varying its concentration (x = 0, 0.05, 0.15 and 0.25). The results show that LiCl forms during ball milling of 6LiBH 4 /CaH 2 /xTiCl 3 and that as temperature increases, o-LiBH 4 transforms into h-LiBH 4 , into which LiCl incorporates, forming solid solution of LiBH 4 ·LiCl, which melts above 280 °C. Molten LiBH 4 ·LiCl is more viscous than molten LiBH 4 , preventing the clustering of LiBH 4 and the accompanied agglomeration of CaH 2 , and thus preserving the nano-sized phase arrangement formed during ball milling. Above 350 °C, the molten solution LiBH 4 ·LiCl further reacts with CaH 2 , precipitating LiCl. The main hydrogen desorption reaction is between molten LiBH 4 ·LiCl and CaH 2 and not between molten LiBH 4 and CaH 2 . This alters the hydrogen reaction thermodynamics and lowers the hydrogen desorption temperature. In addition, the solid–liquid nano-sized phase arrangement in the nano-composites improves the hydrogen reaction kinetics. The reversible incorporation/precipitation of LiCl at the hydrogen reaction temperature and during temperature cycling makes the 6LiBH 4 /CaH 2 /0.25TiCl 3

Synthesis and electrochemical properties of Li4Ti5O12

CSIR Research Space (South Africa)

Liu, GQ

2011-06-01

Full Text Available The spinel compound Li4Ti5O12 was synthesized by a solid state method. In this synthesizing process, anatase TiO2 and Li2CO3 were used as reactants. The influences of reaction temperature and calcination time on the properties of products were...

Order-disorder transition in the complex lithium spinel Li2CoTi3O8

International Nuclear Information System (INIS)

Reeves, Nik; Pasero, Denis; West, Anthony R.

2007-01-01

Li 2 CoTi 3 O 8 has an ordered Li 2 BB' 3 O 8 spinel structure, space group P4 3 32, at room temperature with 3:1 ordering of Ti and Li on the octahedral sites, and Li, Co disordered over the tetrahedral site. Rietveld refinement of variable temperature neutron powder diffraction data has shown an order-disorder phase transition in Li 2 CoTi 3 O 8 which commences at ∼500 deg. C with Li and Co mixing on the tetrahedral and 4-fold octahedral sites and is complete at a first order structural discontinuity at ∼915 deg. C. The fraction of Ti on the 12-fold octahedral site exhibits a small decrease with increasing temperature, which may suggest that the disordering involves all three cations. Above 930 deg. C, the structure, space group Fd3-barm, has Li, Co and Ti sharing a single-octahedral site and Li, Co sharing a tetrahedral site, although Co still exhibits a preference for tetrahedral coordination. A labelling scheme for ordered and partially ordered 3:1 spinels is devised which focuses on the occupancy of the Li,B cations. - Graphical abstract: Rietveld refinement of variable temperature neutron powder diffraction data shows an order-disorder phase transition in Li 2 CoTi 3 O 8 commencing at ∼500 deg. C with Li,Co mixing on tetrahedral and octahedral sites. This becomes complete at a first-order structural discontinuity at ∼915 deg. C. Above 930 deg. C, the structure, space group Fd3-barm, has Li, Co and Ti sharing a single-octahedral site and Li, Co sharing a tetrahedral site

Hydrothermal synthesis of Li4-xNaxTi5O12 and Li4-xNaxTi5O12/graphene composites as anode materials for lithium-ion batteries

Directory of Open Access Journals (Sweden)

Zhu Jiping

2016-01-01

Full Text Available A potential Lithium-ion battery anode material Li4-xNaxTi5O12 (0≤x≤0.15 has been synthesized via a facile hydrothermal method with short processing time and low temperature. The XRD and FE-SEM results indicate that samples with Na-doped are well-crystallized and have more homogeneous particle distributions with smaller overall particle size in the range of 300-600nm. Electrochemical tests reveal that Na-doped samples exhibit impressive specific capacity and cycle stability compared to pristine Li4Ti5O12 at high rate. The Li3.9Na0.1Ti5O12 electrode deliver an initial specific discharge capacity of 169mAh/g at 0.5C and maintained at 150.4mAh/g even after 40 cycles with the reversible retention of 88.99%. Finally, a simple solvothermal reduction method was used to fabricate Li3.9Na0.1Ti5O12/graphene(Li3.9Na0.1Ti5O12/G composite. Galvanostatic charge-discharge tests demonstrate that this sample has remarkable capacities of 197.4mAh/g and 175.5mAh/g at 0.2C and 0.5C rate, respectively. This indicates that the Li3.9Na0.1Ti5O12/G composite is a promising anode material for using in lithium-ion batteries.

Enhanced high-potential and elevated-temperature cycling stability of LiMn2O4 cathode by TiO2 modification for Li-ion battery

International Nuclear Information System (INIS)

Yu Lihong; Qiu Xinping; Xi Jingyu; Zhu Wentao; Chen Liquan

2006-01-01

The surface of spinel LiMn 2 O 4 was modified with TiO 2 by a simple sol-gel method to improve its electrochemical performance at elevated temperatures and higher working potentials. Compared with pristine LiMn 2 O 4 , surface-modification improved the cycling stability of the material. The capacity retention of TiO 2 -modified LiMn 2 O 4 was more than 85% after 60 cycles at high potential cycles between 3.0 and 4.8 V at room temperature and near to 90% after 30 cycles at elevated temperature of 55 deg. C at 1C charge-discharge rate. SEM studies shows that the surface morphology of TiO 2 -modified LiMn 2 O 4 was different from that of pristine LiMn 2 O 4 . Powder X-ray diffraction indicated that spinel was the only detected phase in TiO 2 -modified LiMn 2 O 4 . Introduction of Ti into LiMn 2 O 4 changed the electronic structures of the particle surface. Therefore a surface solid compound of LiTi x Mn 2-x O 4 may be formed on LiMn 2 O 4 . The improved electrochemical performance of surface-modified LiMn 2 O 4 was attributed to the improved stability of crystalline structure and the higher Li + conductivity

Electrochemical and diffusional insights of combustion synthesized SrLi2Ti6O14 negative insertion material for Li-ion Batteries

Science.gov (United States)

Dayamani, Allumolu; Shinde, Ganesh S.; Chaupatnaik, Anshuman; Rao, R. Prasada; Adams, Stefan; Barpanda, Prabeer

2018-05-01

Solvothermal synthetic routes can provide energy-savvy platforms to fabricate battery anode materials involving relatively milder annealing steps vis-à-vis the conventional solid-state synthesis. These energy efficient routes in turn restrict aggressive grain growth to form nanoscale particles favouring efficient Li+ diffusion. Here, we report an economic solution combustion synthesis of SrLi2Ti6O14 anode involving nitrate-urea complexation with a short annealing duration of only 2 h (900 °C). Rietveld refinement confirms the phase purity of target product assuming an orthorhombic framework (Cmca symmetry). It delivers reversible capacity of ∼125 mAh.g-1 at a rate of C/20 involving a 1.38 V Ti4+/Ti3+ redox activity with excellent rate kinetics and cycling stability. Bond valence site energy (BVSE) calculations gauge SrLi2Ti6O14 to be an anisotropic 3D Li+ ion conductor with the highest ionic conductivity along the c direction. The electrochemical and diffusional pathways have been elucidated for combustion prepared SrLi2Ti6O14 as an efficient and safe negative electrode candidate for Li-ion batteries.

107 Définition structurale des linéaments par traitement d'image ...

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The Ngovayang massif represents a key domain in understanding the geodynamics of the northern border of the Congo craton in South Cameroon. Remote sensing works .... linéaments liés au socle rocheux et aux accidents tectoniques (Minyem, 1994 [2]). Ces linéaments sont repartis selon trois directions. - la direction ...

Pebble fabrication of super advanced tritium breeders using a solid solution of Li2+xTiO3+y with Li2ZrO3

Directory of Open Access Journals (Sweden)

Tsuyoshi Hoshino

2016-12-01

Full Text Available Lithium titanate with excess lithium (Li2+xTiO3+y is one of the most promising candidates among advanced tritium breeders for demonstration power plant reactors because of its good tritium release characteristics. However, the tritium breeding ratio (TBR of Li2+xTiO3+y is smaller than that of e.g., Li2O or Li8TiO6 because of its lower Li density. Therefore, new Li-containing ceramic composites with both high stability and high Li density have been developed. Thus, this study focused on the development of a solid solution with a new characteristic. The solid-solution pebbles of Li2+xTiO3+y with Li2ZrO3 (Li2+x(Ti,ZrO3+y, designated as LTZO, were fabricated by an emulsion method. The X-ray diffraction patterns of sintered LTZO pebbles are approximately the same as those of Li2+xTiO3+y pebbles, and no peaks attributable to Li2ZrO3 are observed. These results demonstrate that LTZO pebbles are not a two-phase material but rather a solid solution. Furthermore, LTZO pebbles were easily sintered under air. Thus, the LTZO solid solution is a candidate breeder material for super advanced (SA tritium breeders.

Crystals structure of Na3Li(TiF6)2

International Nuclear Information System (INIS)

Popov, D.Yu.; Antokhina, T.F.; Gerasimenko, A.V.; Kajdalova, T.A.; Sergienko, V.I.

2004-01-01

Crystals of Na 3 Li(TiF 6 ) 2 (1) were synthesized in aqueous solution and characterized by the elementary and X-ray phase analysis methods. According to X-ray diffraction analysis data compound 1 is crystallized in a tetragonal crystal system with the following parameters: a=5.130(1), c=18.046(4) A, Z=2, space group P4-bar2 1 c. Alternating layers on the basis of dimers made up by octahedrons of TiF 6 and Na(1)F 6 constitute the frame of compound 1 crystal structure. The dimer layers are joined in a continuous frame by Na(2) and Li cations. Coordination polyhedron of Li atom is tetrahedron (Li-F 1.898(3) A) [ru

Crystal structure and stability of LiAlD4 with TiF3 additive

International Nuclear Information System (INIS)

Brinks, H.W.; Fossdal, A.; Fonnelop, J.E.; Hauback, B.C.

2005-01-01

LiAlD 4 samples with TiF 3 additives have been investigated by synchrotron X-ray diffraction, neutron diffraction and a Sieverts-type apparatus. Directly after ball milling there are no signs of any Ti-containing phases, and the unit-cell of LiAlD 4 and Al give no indication of any solid solutions. Hence it is concluded that the Ti is in an amorphous state directly after ball milling. Furthermore, no LiF was observed in the samples. Based on Sieverts-type measurements the plateau pressure at 80 deg C has been proved to be higher than 85 bar. Samples stored in a glove box are slowly desorbed, and after 6 months for a LiAlD 4 + TiF 3 sample, the reaction to LiD + Al is nearly finished

Compilation of properties data for Li{sub 2}TiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Roux, N [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

1998-03-01

Properties data obtained at CEA for Li{sub 2}TiO{sub 3} are reported. The compilation includes : stability of Li{sub 2}TiO{sub 3} {beta} phase, specific heat, thermal diffusivity, thermal conductivity, linear thermal expansion, thermal creep, interaction with water and acid. (author)

Density improvement of Li{sub 2}TiO{sub 3} pebbles fabricated by wet process

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, K; Kawamura, H [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Fuchinoue, K; Sawada, H; Watarumi, K

1998-03-01

Lithium titanate (Li{sub 2}TiO{sub 3}) has attracted the attention of many researchers from a point of tritium recovery at low temperature, chemical stability, etc.. The application of small Li{sub 2}TiO{sub 3} sphere has been proposed in some designs of fusion blanket. On the other hand, the wet process is most advantageous as the fabrication method of Li{sub 2}TiO{sub 3} pebbles from a point of mass production, and of reprocessing necessary for effective use of resources and reduction of radioactive wastes. In the preliminary fabrication test, density of Li{sub 2}TiO{sub 3} pebbles was about 40%T.D.. Therefore, in this study, density improvement tests and preliminary characterization of Li{sub 2}TiO{sub 3} pebbles by wet process were performed, noting the aging condition and sintering condition in the fabrication process of the gel-spheres. This study yielded Li{sub 2}TiO{sub 3} pebbles in target range of 80-85%T.D.. (author)

A promising tritium breeding material: Nanostructured 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles

Science.gov (United States)

Dang, Chen; Yang, Mao; Gong, Yichao; Feng, Lan; Wang, Hailiang; Shi, Yanli; Shi, Qiwu; Qi, Jianqi; Lu, Tiecheng

2018-03-01

As an advanced tritium breeder material for the fusion reactor blanket of the International Thermonuclear Experimental Reactor (ITER), Li2TiO3-Li4SiO4 biphasic ceramic has attracted widely attention due to its merits. In this paper, the uniform precursor powders were prepared by hydrothermal method, and nanostructured 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles were fabricated by an indirect wet method at the first time. In addition, the composition dependence (x/y) of their microstructure characteristics and mechanical properties were investigated. The results indicated that the crush load of biphasic ceramic pebbles was better than that of single phase ceramic pebbles under identical conditions. The 2Li2TiO3-Li4SiO4 ceramic pebbles have good morphology, small grain size (90 nm), satisfactory crush load (37.8 N) and relative density (81.8 %T.D.), which could be a promising breeding material in the future fusion reactor.

Improved hydrogen storage properties of LiAlH4 by mechanical milling with TiF3

International Nuclear Information System (INIS)

Zang, Lei; Cai, Jiaxing; Zhao, Lipeng; Gao, Wenhong; Liu, Jian; Wang, Yijing

2015-01-01

Dehydrogenation behavior of LiAlH 4 (lithium alanate) admixed with TiF 3 is investigated by pressure-composition-temperature (PCT), fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), differential scanning calorimetry (DSC) and temperature programmed desorption (TPD). The TiF 3 addition enhances kinetics of LiAlH 4 and decreases the decomposition temperature. The LiAlH 4 -2 mol % TiF 3 sample starts to release hydrogen at about 35 °C and the dehydrogenation rate reaches a maximum value at 108.4 °C, compared with 145 °C and 179.9 °C for the as-received LiAlH 4 . As for the dehydrogenation kinetics, the LiAlH 4 -2 mol % TiF 3 sample releases about 7.0 wt % H 2 at 140 °C within 80 min. In comparison, the as-received LiAlH 4 sample releases only 0.8 wt % hydrogen under the same conditions. The existence of proposed catalyst, Al 3 Ti formed in-situ in the process of dehydrogenation, has been confirmed experimentally by XRD measurements. The activation energy of LiAlH 4 -2 mol % TiF 3 composite is deduced to be 66.76 kJ mol −1 and 88.21 kJ mol −1 for the first and second reaction stages of LiAlH 4 dehydrogenation. - Highlights: • TiF 3 considerably enhances the dehydrogenation kinetics of LiAlH 4 . • TiF 3 -doped LiAlH 4 dehydrogenates even at room temperature. • Low activation energy of the dehydrogenation reaction. • Al 3 Ti formed in-situ helps to explain the dehydrogenation mechanism

Li vaporization property of two-phase material of Li{sub 2}TiO{sub 3} and Li{sub 2}SiO{sub 3} for tritium breeder

Energy Technology Data Exchange (ETDEWEB)

Ogawa, Seiya [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Masuko, Yuki; Kato, Hirokazu; Yuyama, Hayato; Sakai, Yutaro [Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Niwa, Eiki; Hashimoto, Takuya [Department of Physics, College of Humanities and Sciences, Nihon University, 3-8-1 Sakurajousui, Setagaya-ku, Tokyo 156-8550 (Japan); Mukai, Keisuke [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-8656 (Japan); Hosino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuch, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Sasaki, Kazuya, E-mail: k_sasaki@tokai-u.jp [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Course of Mechanical Engineering and Aeronautics and Astronautics, Graduate School of Science and Technology, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)

2015-10-15

Highlights: • We synthesized two phase materials based on Li{sub 2}SiO{sub 3} and Li{sub 2}TiO{sub 3}. • We investigated the Li vaporization property of the two-phase materials. • Li vaporization occurs significantly from only Li{sub 2}SiO{sub 3} grains in the vicinity of the surface of the pellets. • The Li vaporization is remarkable only for an early short time for the vaporization from Li{sub 2}SiO{sub 3} grains at the vicinity of the surface. • The second stable phase added functions effectively for inhibition of the Li vaporization. - Abstract: Li vaporization property of two-phase materials of Li{sub 2}TiO{sub 3} and Li{sub 2}SiO{sub 3} in a working condition for the solid tritium breeder used in the demonstration power plant of fusion reactor was investigated, and the suppression mechanism of the vaporization was considered. The Li vaporization rate from the specimen pellet was measured by gravimetric method, and the change of Li concentration distribution in the pellet was analyzed by time-of-flight secondary ion mass spectrometer. Li was vaporized only from the Li{sub 2}SiO{sub 3} at the vicinity of the surface of the pellet. The remarkable vaporization of Li arose only in an early short time. The inhibition of the vaporization from the Li{sub 2}SiO{sub 3} was successful by adding the small amount of the stable secondary phase of Li{sub 2}TiO{sub 3}.

Electrochemical studies on electrospun Li(Li1/3Ti5/3)O4 grains as an anode for Li-ion batteries

International Nuclear Information System (INIS)

Wu Yongzhi; Reddy, M.V.; Chowdari, B.V.R.; Ramakrishna, S.

2012-01-01

Highlights: ► We report (Li(Li 1/3 Ti 5/3 )O 4 ) (LTO) obtained via electrospinning and followed by heat treatment. ► Electrochemical studies on nano-LTO showed a reversible capacity of 165(±3) mAh g −1 and 78(±3) mAh g −1 at a current rate of 0.2 C and 10 C, respectively. ► Electrode kinetics studies of LTO were carried out the end of 380 cycle using GITT and EIS techniques. - Abstract: Li(Li 1/3 Ti 5/3 )O 4 or (Li 4 Ti 5 O 12 ) (LTO) grains are prepared via electrospinning a solution containing lithium acetate, titanium tetra(IV)-isopropoxide, polyvinyl acetate and acetic acid in N,N-dimethyl-formamide, followed by a subsequent sintering process. The structures and morphology were characterized by X-ray diffraction, scanning and transmission microscopy. Coin-type cells were assembled to test the electrochemical performance was evaluated using galvanostatic cycling at room temperature, in the cycling range, 1.0–2.8 V. The Li-cycling results showed characteristic discharge-charge plateaus at 1.55 and 1.8 V vs. Li/Li + , respectively. Electrospun LTO showed a reversible capacity of 165(±3) mAh g −1 at the end of 10th cycle at a current rate of 0.2 C. The later studies on rate capacities and cycling performance of LTO grains demonstrate good rate performance and long term cycling stability. Galvanostatic Intermittent Titration Technique (GITT) and Electrochemical Impedance Spectroscopy (EIS) studied were carried out at end of 381st and 382nd cycle to understand the electrode kinetics.

Improved the lithium storage capability of BaLi2Ti6O14 by electroless silver coating

International Nuclear Information System (INIS)

Lin, Xiaoting; Wang, Pengfei; Li, Peng; Yu, Haoxiang; Qian, Shangshu; Shui, Miao; Wang, Dongjie; Long, Nengbing; Shu, Jie

2015-01-01

Highlights: • BaLi 2 Ti 6 O 14 /Ag is fabricated via a facile electroless deposition. • Highly dispersed Ag nanoparticles are successively coated on BaLi 2 Ti 6 O 14 . • BaLi 2 Ti 6 O 14 /Ag is used as anode material for lithium storage. • BaLi 2 Ti 6 O 14 /Ag exhibits improved lithium storage capability. - Abstract: To form BaLi 2 Ti 6 O 14 /Ag, highly dispersed Ag nanoparticles are successfully deposited on the surface of BaLi 2 Ti 6 O 14 by a simple chemical deposition method. The morphology, quantity and size of Ag nanoparticles in BaLi 2 Ti 6 O 14 /Ag composites are significantly influenced by the Ag coating contents. Electrochemical results show that Ag nanoparticles play a positive role in reducing redox polarization and improving electrical conductivity of BaLi 2 Ti 6 O 14 during lithiation/delithiation processes. Among all the as-obtained products, 6 wt.% Ag coated BaLi 2 Ti 6 O 14 shows the highest initial charge specific capacity of 160 mAh g −1 at the current density of 100 mA g −1 (1C), which is much higher than the 149.1 mAh g −1 for bare BaLi 2 Ti 6 O 14 . After 100 charge/discharge cycles, the reversible capacity can be maintained at 117.0 mAh g −1 . Moreover, this sample also shows excellent rate performance with high reversible charge capacities of 147.5, 139.7, 132.6, and 126.7 mAh g −1 at the rates of 2C, 3C, 4C and 5C, respectively. Compared with bare BaLi 2 Ti 6 O 14 , the superior electrochemical performance indicates that BaLi 2 Ti 6 O 14 /Ag can be a good anode material in lithium ion batteries.

Synthesis of Li4Ti5O12 and its electrochemical properties

CSIR Research Space (South Africa)

Liu, G

2011-12-01

Full Text Available Lithium-ion batteries are now well established in the market as the rechargeable power source. The spinel Li4Ti5O12 has many advantages over the graphite, although, which has been used as anode since lithium ion batteries was invented. Li4Ti5O12...

High Tap Density Li4Ti5O12 Microspheres: Synthetic Conditions and Advanced Electrochemical Performance

KAUST Repository

Ming, Jun; Zheng, Junwei; Zhou, Qun; Ren, Jianxin; Ming, Hai; Jia, Zhenyong; Zhang, Yanqing

2017-01-01

Preparation of uniform spherical Li4Ti5O12 with high tap density is significant to achieve a high volumetric energy density in lithium-ion batteries. Herein, Li4Ti5O12 micro-spheres with variable tap-density and tunable size distribution were synthesized by a newly designed industrial spray drying approach. The slurry concentration, sintering time and sintering conditions after spray, the effect of Li/Ti molar ratio on the lithium ion (Li+) storage capability were investigated. A narrow particle size distribution around 10 μm and high tap-density close to 1.4 g cm-3 of the Li4Ti5O12 spheres can be obtained under the optimized conditions. The Li4Ti5O12 spheres can deliver much higher capacity of 168 mAh g-1 at 1 C-rate and show high capacity retention of 97.7% over 400 cycles. The synthetic conditions are confirmed to be critical for improving the electron conductivity and Li+ diffusivity by adjusting the crystal and spatial structures. As-prepared high performance Li4Ti5O12 is an ideal electrode for Li-ion batteries or capacitors; meanwhile the presented approach is also applicable for preparing other kind of spherical materials.

High Tap Density Li4Ti5O12 Microspheres: Synthetic Conditions and Advanced Electrochemical Performance

KAUST Repository

Ming, Jun

2017-03-17

Preparation of uniform spherical Li4Ti5O12 with high tap density is significant to achieve a high volumetric energy density in lithium-ion batteries. Herein, Li4Ti5O12 micro-spheres with variable tap-density and tunable size distribution were synthesized by a newly designed industrial spray drying approach. The slurry concentration, sintering time and sintering conditions after spray, the effect of Li/Ti molar ratio on the lithium ion (Li+) storage capability were investigated. A narrow particle size distribution around 10 μm and high tap-density close to 1.4 g cm-3 of the Li4Ti5O12 spheres can be obtained under the optimized conditions. The Li4Ti5O12 spheres can deliver much higher capacity of 168 mAh g-1 at 1 C-rate and show high capacity retention of 97.7% over 400 cycles. The synthetic conditions are confirmed to be critical for improving the electron conductivity and Li+ diffusivity by adjusting the crystal and spatial structures. As-prepared high performance Li4Ti5O12 is an ideal electrode for Li-ion batteries or capacitors; meanwhile the presented approach is also applicable for preparing other kind of spherical materials.

Structural characterisation and physical properties of Li MMnO 4 ( M=Cr, Ti) spinels

Science.gov (United States)

Arillo, M. A.; Cuello, G.; López, M. L.; Martín, P.; Pico, C.; Veiga, M. L.

2005-01-01

New spinel-type phases of general formula Li MMnO 4 ( M=Cr, Ti), derived from LiMn 2O 4 by substitution of Mn 3+ by Cr 3+ or Mn 4+ by Ti 4+, have been obtained and characterised. Neutron diffraction refinements confirm that both phases crystallise in the Fd3m space group, giving the cation distributions [Li] 8 a[CrMn] 16 dO 4 and [Li 0.66Ti 0.34] 8 a[Li 0.34MnTi 0.66] 16 dO 4. Electrical conductivity has been examined by various techniques showing that these materials behave as semiconductors. The electrochemical behaviour indicates different oxidation-reduction steps in both cases concomitant with the insertion/deinsertion of lithium in non-reversible processes. X-ray diffraction patterns show that the above process is topotactic in LiCrMnO 4. Magnetic data and neutron diffraction measurements show that no long-range magnetic ordering is present, suggesting a spin-glass transition for M=Cr at low temperature, while for M=Ti the presence of non-magnetic ions in the octahedral sublattice provokes an inherent magnetic frustration.

Ramsdellite-structured LiTiO 2: A new phase predicted from ab initio calculations

Science.gov (United States)

Koudriachova, M. V.

2008-06-01

A new phase of highly lithiated titania with potential application as an anode in Li-rechargeable batteries is predicted on the basis of ab initio calculations. This phase has a composition LiTiO2 and may be accessed through electrochemical lithiation of ramsdellite-structured TiO2 at the lowest potential reported for titanium dioxide based materials. The potential remains constant over a wide range of Li-concentrations. The new phase is metastable with respect to a tetragonally distorted rock salt structure, which hitherto has been the only known polymorph of LiTiO2.

In-pile test of Li 2TiO 3 pebble bed with neutron pulse operation

Science.gov (United States)

Tsuchiya, K.; Nakamichi, M.; Kikukawa, A.; Nagao, Y.; Enoeda, M.; Osaki, T.; Ioki, K.; Kawamura, H.

2002-12-01

Lithium titanate (Li 2TiO 3) is one of the candidate materials as tritium breeder in the breeding blanket of fusion reactors, and it is necessary to show the tritium release behavior of Li 2TiO 3 pebble beds. Therefore, a blanket in-pile mockup was developed and in situ tritium release experiments with the Li 2TiO 3 pebble bed were carried out in the Japan Materials Testing Reactor. In this study, the relationship between tritium release behavior from Li 2TiO 3 pebble beds and effects of various parameters were evaluated. The ( R/ G) ratio of tritium release ( R) and tritium generation ( G) was saturated when the temperature at the outside edge of the Li 2TiO 3 pebble bed became 300 °C. The tritium release amount increased cycle by cycle and saturated after about 20 pulse operations.

Tritium release behavior from neutron-irradiated Li{sub 2}TiO{sub 3} single crystal

Energy Technology Data Exchange (ETDEWEB)

Tanifuji, Takaaki; Yamaki, Daiju; Noda, Kenji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nasu, Shoichi

1998-03-01

Li{sub 2}TiO{sub 3} single-crystals with various size (1-2mm) were used as specimens. After the irradiation up to 4 x 10{sup 18} n/cm{sup 2} with thermal neutrons in JRR-2, tritium release from the Li{sub 2}TiO{sub 3} specimens in isothermal heating tests was continuously measured with a proportional counter. The tritium release in the range from 625K to 1373K seems to be controlled by bulk diffusion. The tritium diffusion coefficient (D{sub T}) in Li{sub 2}TiO{sub 3} was evaluated to be D{sub T}(cm{sup 2}/sec) = 0.100exp(-104(kJ/mol)/RT), 625KLi{sub 2}TiO{sub 3} is almost equal to those of Li{sub 2}O irradiated with thermal neutrons up to 2 x 10{sup 19} n/cm{sup 2}. It indicates that the tritium release performance of Li{sub 2}TiO{sub 3} is essentially good as Li{sub 2}O. (author)

Solution based synthesis of mixed-phase materials in the Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} system

Energy Technology Data Exchange (ETDEWEB)

Hanaor, Dorian A.H., E-mail: dorian.hanaor@sydney.edu.au [School of Civil Engineering, University of Sydney, NSW 2006 (Australia); Kolb, Matthias H.H. [Institute for Applied Materials, Karlsruhe Institute of Technology, 76021 (Germany); Gan, Yixiang [School of Civil Engineering, University of Sydney, NSW 2006 (Australia); Kamlah, Marc; Knitter, Regina [Institute for Applied Materials, Karlsruhe Institute of Technology, 76021 (Germany)

2015-01-15

Highlights: • Investigation of phase stability in the quasi-binary Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} system. • Sol-based syntheses of mixed phase materials from organometallic precursors. • LiCl based synthesis results in greater lithium deficiency than LiOH synthesis. • The Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} quasi binary system appears to exhibit monotectic behaviour. • Mixed phase materials show liquid formation from melting of silicate material at 1100 °C. - Abstract: As candidate tritium breeder materials for use in the ITER helium cooled pebble bed, ceramic multiphasic compounds lying in the region of the quasi-binary lithium metatitanate–lithium orthosilicate system may exhibit mechanical and physical advantages relative to single phase materials. Here we present an organometallic solution-based synthesis procedure for the low-temperature fabrication of compounds in the Li{sub 2}TiO{sub 3}–Li{sub 4}SiO{sub 4} region and investigate phase stability and transformations through temperature varied X-ray diffraction and scanning calorimetry. Results demonstrate that the metatitanate and metasilicate phases Li{sub 2}TiO{sub 3} and Li{sub 2}SiO{sub 3} readily crystallise in nanocrystalline form at temperatures below 180 °C. Lithium deficiency in the region of 5% results from Li sublimation from Li{sub 4}SiO{sub 4} and/or from excess Li incorporation in the metatitanate phase and brings about a stoichiometry shift, with product compounds exhibiting mixed lithium orthosilicate/metasilicate content towards the Si rich region and predominantly Li{sub 2}TiO{sub 3} content towards the Ti rich region. Above 1150 °C the transformation of monoclinic to cubic γ-Li{sub 2}TiO{sub 3} disordered solid-solution occurs while the melting of silicate phases indicates a likely monotectic type system with a solidus line in the region 1050–1100 °C. Synthesis procedures involving a lithium chloride precursor are not likely to be a viable option for

Solid-state synthesis of Li_4Ti_5O_1_2 whiskers from TiO_2-B

International Nuclear Information System (INIS)

Yao, Wenjun; Zhuang, Wei; Ji, Xiaoyan; Chen, Jingjing; Lu, Xiaohua; Wang, Changsong

2016-01-01

Highlights: • The Li_4Ti_5O_1_2 whiskers were synthesized from TiO_2-B whiskers via a solid state reaction. • The TiO_2-B crystal structure for lithium diffusion is easier than anatase. • The separated diffusion and reaction process is crucial for the solid-state syntheses of Li_4Ti_5O_1_2 whiskers. - Abstract: In this work, Li_4Ti_5O_1_2 (LTO) was synthesized from the precursors of TiO_2-B and anatase whiskers, respectively. The synthesized LTO whiskers from TiO_2-B whiskers via a solid state reaction at 650 °C have a high degree of crystallinity with an average diameter of 300 nm. However, when anatase whiskers were used as the precursor, only particle morphology LTO was produced at 750 °C. The further analysis of the precursors, the intermediate products and the final products reveal that the crystal structure of the anatase hinders the diffusion of lithium, leading to a typical reaction–diffusion process. Under this condition, only particle morphology LTO can be produced. However, the crystal structure of the TiO_2-B is easy for lithium diffusion and the process is performed in two separated steps (i.e., diffusion and reaction), which makes it possible to decrease the solid-state reaction temperature down to 650 °C and then maintain the morphologies of whiskers.

Improved capacity and rate capability of Ru-doped and carbon-coated Li4Ti5O12 anode material

International Nuclear Information System (INIS)

Lin, Chih-Yuan; Jhan, Yi-Ruei; Duh, Jenq-Gong

2011-01-01

Highlights: → By using a simple one-step solid-state reactions method synthesizes Li 4 Ru 0.01 Ti 4.99 O 12 /C anode material. → Combining the Ru-doped and carbon-coated techniques to fabricate Li 4 Ru 0.01 Ti 4.99 O 12 /C effectively enhance the diffusion rate of Li + and significantly reduce surface electronic resistance of Li 4 Ti 5 O 12 . → Li 4 Ru 0.01 Ti 4.99 O 12 /C delivers 120 and 110 mAh g -1 at 5 and 10 C charge/discharge rate, respectively, after 100 charge/discharge cycles. - Abstract: Pure Li 4 Ti 5 O 12 , modified Li 4 Ti 5 O 12 /C, Li 4 Ru 0.01 Ti 4.99 O 12 and Li 4 Ru 0.01 Ti 4.99 O 12 /C were successfully prepared by a modified solid-state method and its electrochemical properties were investigated. From the XRD patterns, the added sugar or doped Ru did not affect the spinel structure. The results of electrochemical properties revealed that Li 4 Ru 0.01 Ti 4.99 O 12 /C showed 120 and 110 mAh/g at 5 and 10 C rate after 100 charge/discharge cycles. Li 4 Ru 0.01 Ti 4.99 O 12 /C exhibited the best rate capability and the highest capacity at 5 and 10 C charge/discharge rate owing to the increase of electronic conductivity and the reduction of interface resistance between particles of Li 4 Ti 5 O 12 .It is expected that the Li 4 Ru 0.01 Ti 4.99 O 12 /C will be a promising anode material to be used in high-rate lithium ion battery.

Advanced LiTi2(PO4)3@N-doped carbon anode for aqueous lithium ion batteries

International Nuclear Information System (INIS)

He, Zhangxing; Jiang, Yingqiao; Meng, Wei; Zhu, Jing; Liu, Yang; Dai, Lei; Wang, Ling

2016-01-01

Highlights: • LiTi 2 (PO 4 ) 3 @N-doped carbon anode was prepared by in-situ coating approach for aqueous lithium ion batteries. • The well-proportioned N-doped carbon layer and loose nanoporous structure was obtained using urea as nitrogen source and pore former. • LiTi 2 (PO 4 ) 3 @N-doped carbon demonstrates excellent rate performance and good cycling stability. - Abstract: In this paper, LiTi 2 (PO 4 ) 3 @N-doped carbon anode has been synthesized by in situ carbon coating approach. The well-proportioned N-doped carbon layer and loose nanoporous structure was obtained by using urea as nitrogen source and pore former. LiTi 2 (PO 4 ) 3 @N-doped carbon as anode demonstrates much better rate capability than LiTi 2 (PO 4 ) 3 @carbon in ALIBs. The optimized anode delivers the discharge capacity of 93.7 mAh g −1 and 74.2 mAh g −1 at rates of 10C and 20C, 22.5 mAh g −1 and 50.0 mAh g −1 larger than that of LiTi 2 (PO 4 ) 3 @carbon. Moreover, LiTi 2 (PO 4 ) 3 @N-doped carbon exhibits excellent cycling performance with capacity retention of 84.3% at 5C after 1000 cycles. As verified, the well-proportioned N-doped carbon layer could reduce charge transfer resistance and improve electrical conductivity. The loose nanoporous structure could shorten pathway and facilitate diffusion for Li ion. Therefore, LiTi 2 (PO 4 ) 3 @N-doped carbon gets the superior electrochemical properties benefiting from those two characteristics.

Synthesis of Li2MO3 (M = Ti or Zr) by the combustion method

International Nuclear Information System (INIS)

Cruza, D.; Bulbuliana, S.; Cruza, D.; Pfeifferc, H.

2006-01-01

The advantages and disadvantages of the combustion method to prepare Li 2 TiO 3 and Li 2 ZrO 3 ceramics were studied. Firstly, the ceramic powders were prepared by the combustion process using LiOH, MO 2 (where M=Ti or Zr) and urea in different molar ratios (from 2:1:3 to 3:1:3) at different temperatures for 5 minutes. Li 2 TiO 3 and Li 2 ZrO 3 were also obtained by the solid-state method, and the results were compared with those obtained by the combustion process. The powders were characterized by X-ray diffraction and scanning electron microscopy. It was found that the combustion process reduces the synthesis time of Li 2 TiO 3 (1 minute at 750 C), but it does not have any advantage on producing Li 2 ZrO 3 , due to thermodynamic factors. On the other hand, the combustion process produces carbon contaminants in the solids. It was necessary to add excess of lithium hydroxide, in order to compensate the quantity of Li sublimated during the production of the ceramics. Finally, it seems that both reactions follow the same mechanism, which is determined by the lithium diffusion into the metal oxides. (authors)

Promotional role of Li4Ti5O12 as polysulfide adsorbent and fast Li+ conductor on electrochemical performances of sulfur cathode

Science.gov (United States)

Zeng, Tianbiao; Hu, Xuebu; Ji, Penghui; Shang, Biao; Peng, Qimeng; Zhang, Yaoyao; Song, Ruiqiang

2017-08-01

Lithium-sulfur (Li-S) batteries attract much attention due to its high specific capacity and energy density compared to lithium-ion batteries (LiBs). Herein, a novel composite named as (void/nano-Li4Ti5O12 pieces)@C [(v/n-L)@C] was designed and prepared as a sulfur host. Spinel Li4Ti5O12 here as a multifunctional additive played as polysulfide adsorbent agent and fast Li+ conductor, and carbon shell was designed as electronic conductor, as well as volume barrier to limit the volume expansion caused by sulfur. As-prepared (S/nano-Li4Ti5O12 pieces)@C [(S/n-L)@C] are core-shell spheres, which are about 200 nm in size. Nano-Li4Ti5O12 and sulfur were coated by the outer carbon shell with a thickness of about 20 nm. The experimental results show that electrochemical performances of (S/n-L)@C cathode were enhanced effectively compared to S@C cathode. At 0.5C and 1C, the discharge capacity of (S/n-L)@C was 33.5% and 40.1% higher than that of S@C at 500th cycle. Even at 2C, its capacity reached 600.9 mAh g-1 at 1000th cycle. Li+ conductivity of (S/n-L)@C was one order of magnitude higher than that of S@C, which was reach to 2.55 × 10-8 S cm-1. The experiment results indicate Li4Ti5O12 plays a promotional role on electrochemical performances of sulfur cathode, especially for stable cycling performance and high rate performance.

Impedance spectroscopy of Li2CO3 doped (Ba,Sr)TiO3 ceramic

Science.gov (United States)

Ham, Yong-Su; Koh, Jung-Hyuk

2013-02-01

(BaxSr1-x)TiO3-based ceramic has been considered as one of the most important electronic materials widely employed in microwave passive device applications. Many researches have been performed to lower the high sintering temperature, by adding various dopants such as B2O3, La2O3, etc. In our previous study, by adding Li2CO3 to (Ba0.5,Sr0.5)TiO3 ceramics, the sintering temperature of Li2CO3 doped (Ba0.5,Sr0.5)TiO3 ceramics decreased from 1350 to 900 °C. This study observed the crystalline structure and electrical properties of Li2CO3 doped (Ba0.5,Sr0.5)TiO3 ceramics. In scanning the crystalline structure of Li2CO3 doped (Ba0.5,Sr0.5)TiO3 ceramics, no pyro phase was observed by X-ray diffraction analysis. To investigate the electrical properties of Li2CO3 doped (Ba0.5,Sr0.5)TiO3 ceramics, real and imaginary parts of the impedances were analyzed. Complex impedance data were measured from 100 Hz to 1 MHz at various temperature ranges.

Microwave dielectric properties of low-fired Li_2TiO_3–MgO ceramics for LTCC applications

International Nuclear Information System (INIS)

Ma, Jian-Li; Fu, Zhi-Fen; Liu, Peng; Wang, Bing; Li, Yang

2016-01-01

Graphical abstract: This figure gives the Q × f and τ_f of Li_2TiO_3–MgO ceramics sintered at various temperatures with different LiF contents. Addition of LiF enhanced the sinterability and optimized the microwave dielectric properties of Li_2TiO_3–MgO ceramics. The excellent microwave dielectric properties (ε_r = 15.8, Q × f = 64,500 GHz, and τ_f = −0.2 ppm/°C) of Li_2TiO_3–MgO ceramics sintered at 850 °C illustrated that LiF is a simple effective sintering aids for Li_2TiO_3–MgO ceramics. Such sample was compatible with Ag electrodes, suitable for the low-temperature co-fired ceramics (LTCC) applications. - Highlights: • Temperature stability of Li_2TiO_3 ceramics were improved by doping MgO. • The low-fired Li_2TiO_3–MgO ceramics are fabricated. • LiF liquid phase reduced sintering temperature of Li_2TiO_3–MgO ceramics to 850 °C. • The low-fired Li_2TiO_3–MgO ceramics possess well microwave dielectric properties. • The sample was compatible with Ag electrodes and suitable for LTCC applications. - Abstract: We fabricated the low-fired Li_2TiO_3–MgO ceramics doped with LiF by a conventional solid-state route, and investigated systematically their sintering characteristics, microstructures and microwave dielectric properties. The results showed that temperature stability of Li_2TiO_3 ceramics were improved by doping MgO. Well microwave dielectric properties for Li_2TiO_3–13 wt%MgO (LTM) ceramics with ε_r = 16.4, Q × f = 87,500 GHz, and τ_f = −1.2 ppm/°C were obtained at 1325 °C. Furthermore, addition of LiF enhanced the sinterability and optimized the microwave dielectric properties of LTM ceramics. A typically sample of LTM-4 wt%LiF ceramics with optimum dielectric properties (ε_r = 15.8, Q × f = 64,500 GHz, and τ_f = −0.2 ppm/°C) were achieved at 850 °C for 4 h. Such sample was compatible with Ag electrodes, suitable for the low-temperature co-fired ceramics (LTCC) applications.

Search for the signature of a halo structure in the p(6He,6Li)n reaction

International Nuclear Information System (INIS)

Cortina-Gil, M.D.; Roussel-Chomaz, P.; Mittig, W.; Casandjian, J.M.; Chartier, M.; Alamanos, N.; Auger, F.; Fekou-Youmbi, V.; Blumenfeld, Y.; and others.

1995-01-01

The elastic scattering p( 6 He, 6 He)p and charge exchange reaction p( 6 He, 6 Li)n have been measured in reverse kinematics with a secondary 6 He beam. The angular distributions for these reactions were obtained. In the case of the charge exchange reaction, the ratio of the cross section for the Gamow-Teller transition to the ground state, and for the Fermi transition to the isobaric analog state is a measure of the relative strength of the two components of the exchange interaction. This ratio is found compatible with existing systematics for stable T=1 nuclei, and no clear signature of a halo structure was found in the present data. (author)

Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24}: A new anode material for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Lin, Chunfu, E-mail: linchunfu@hainu.edu.cn [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, College of Materials and Chemical Engineering, Hainan University, Haikou 570228, Hainan (China); Deng, Shengjue; Shen, Hong; Wang, Guizhen; Li, Yanfang; Yu, Lei; Lin, Shiwei; Li, Jianbao [Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources, College of Materials and Chemical Engineering, Hainan University, Haikou 570228, Hainan (China); Lu, Li, E-mail: luli@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 (Singapore)

2015-11-25

Li{sub 4}Ti{sub 5}O{sub 12} suffers from its small theoretical capacity and low conductivity, limiting its practical applications in lithium-ion batteries. Although its conductivity has been improved, its theoretical capacity has not been increased so far. Here, for the first time, the capacity of Li{sub 4}Ti{sub 5}O{sub 12} is increased by combining Ti{sup 3+}/Ti{sup 4+} and Cr{sup 2+}/Cr{sup 3+} redox couples. Spinel Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} with a larger theoretical capacity of 323 mAh g{sup −1} is designed and fabricated through a facile solid-state reaction method. The as-fabricated Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} delivers a large initial discharge capacity of 311 mAh g{sup −1} between 3 and 0.001 V (vs. Li/Li{sup +}) at a current density of 62.5 mA g{sup −1}, which is larger than that of Li{sub 4}Ti{sub 5}O{sub 12}. Furthermore, it exhibits good (electronic and ionic) conductivity and a high rate performance. - Highlights: • Capacity of Li{sub 4}Ti{sub 5}O{sub 12} is increased by combining Ti{sup 3+}/Ti{sup 4+} and Cr{sup 2+}/Cr{sup 3+} couples. • Spinel Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} with a larger theoretical capacity of 323 mAh g{sup −1} is prepared. • Discharge and charge capacities of Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} are larger than those of Li{sub 4}Ti{sub 5}O{sub 12}. • Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} shows a large electronic conductivity and Li{sup +} diffusion coefficient. • Li{sub 5}Cr{sub 9}Ti{sub 4}O{sub 24} further exhibits an ultra-high rate performance and good cyclability.

Carbon coated Li4Ti5O12 nanorods as superior anode material for high rate lithium ion batteries

International Nuclear Information System (INIS)

Luo, Hongjun; Shen, Laifa; Rui, Kun; Li, Hongsen; Zhang, Xiaogang

2013-01-01

Highlights: •A novel approach has been developed to fabricate 1D Li 4 Ti 5 O 12 /C nanorods by a wet-chemical route. •Carbon coating layer effectively restrict the particle growth and enhance electronic conductivity. •The Li 4 Ti 5 O 12 /C nanorods exhibit remarkable rate capability and long cycle life. -- Abstract: We describe a novel approach for the synthesis of carbon coated Li 4 Ti 5 O 12 (Li 4 Ti 5 O 12 /C) nanorods for high rate lithium ion batteries. The carbon coated TiO 2 nanotubes using the glucose as carbon source are first synthesized by hydrothermal treatment. The commercial anatase TiO 2 powder is immersed in KOH sulotion and subsequently transforms into Li 4 Ti 5 O 12 /C in LiOH solution under hydrothermal condition. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption/desorption and Raman spectra are performed to characterize their morphologies and structures. Compared with the pristine Li 4 Ti 5 O 12 , one-dimensional (1D) Li 4 Ti 5 O 12 /C nanostructures show much better rate capability and cycling stability. The 1D Li 4 Ti 5 O 12 /C architectures effectively restrict the particle growth and enhance their electronic conductivity, enabling fast ion and electron transport

Electrochemical performance of La2O3/Li2O/TiO2 nano-particle coated cathode material LiFePO4.

Science.gov (United States)

Wang, Hong; Yang, Chi; Liu, Shu-Xin

2014-09-01

Cathode material, LiFePO4 was modified by coating with a thin layer of La2O3/Li2O/TiO2 nano-particles for improving its performance for lithium ion batteries. The morphology and structure of the modified cathode material were characterized by powder X-ray diffraction, scanning electron microcopy and AES. The performance of the battery with the modified cathode material, including cycling stability, C-rate discharge was examined. The results show that the battery composed of the coated cathode materials can discharge at a large current density and show stable cycling performance in the range from 2.5 to 4.0 V. The rate of Li ion diffusion increases in the battery with the La2O3/Li2O/TiO2-coated LiFePO4 as a cathode and the coating layer may acts as a faster ion conductor (La(2/3-x)Li(3x)TiO3).

KBr-Li Br and KBr-LiBr doped with Ti mixed single crystal by Czochralski method and glow curve studies

International Nuclear Information System (INIS)

Faripour, H.; Faripour, N.

2003-01-01

Mixed-single Crystals: pure KBr-LiBr and KBr-LiBr with Ti dopant were grown by Czochralski method. Because of difference between lattice parameters of KBr and LiBr, the growth speed of crystals were relatively low, and they were annealed in a special temperature condition providing some cleavages. They were exposed by β radiation and the glow curve was analysed for each crystal. Analysing of glow curve, showed that Ti impurity has been the curves of main peak curve appearance temperature decreasing

Li4Ti5O12 thin-film electrodes by in-situ synthesis of lithium alkoxide for Li-ion microbatteries

International Nuclear Information System (INIS)

Mosa, J.; Aparicio, M.; Tadanaga, K.; Hayashi, A.; Tatsumisago, M.

2014-01-01

Rechargeable thin-film batteries have recently become the topic of widespread research for use as efficient energy storage devices. Spinel Li 4 Ti 5 O 12 has been considered as one of the most prospective anode materials for Li-ion batteries because of its excellent reversibility and long cycle life. We report here the sol–gel synthesis and coating preparation of spinel thin-film Li 4 Ti 5 O 12 electrodes for Li-ion microbatteries using lithium ethoxide produced in situ that reacts with titanium alkoxide to produce the precursor solution without particle precipitation. This synthesis procedure reduces the thermal treatment to obtain a pure phase at only 700 °C and 15 minutes. The physical and structural characterization of the 300 nm Li 4 Ti 5 O 12 coatings shows a very homogeneous distribution of elements and a pure spinel phase. Galvanostatic discharge-charge tests indicate maximum discharge capacities of 152 mA h g −1 when the material is treated at 700 °C for 15 minutes

Solid State Formation Mechanism of Li₄Ti₅O₁₂ from an Anatase TiO₂ Source

DEFF Research Database (Denmark)

Shen, Yanbin; Søndergaard, Martin; Christensen, Mogens

2014-01-01

Solid state synthesis of Li4Ti5O12 anode material for Li ion batteries typically results in products containing rutile TiO2 and Li2TiO3 impurities, and subsequent high calcination temperatures lead to particle growth that reduces capacity and rate ability. Here, the formation and growth of Li4Ti5O......12 particles by a solid-state reaction using anatase TiO2 with various crystallite sizes and Li2CO3 is investigated by in situ high temperature powder X-ray diffraction (HT-PXRD) and thermal gravimetry-differential thermal analysis (TG-DTA). The combined data provide insight into the origin...... crystallite sizes (∼50 nm, ∼30 nm, ∼20 nm, and amorphous) were explored, and decreasing crystallite sizes causes a reduced initial reaction temperature. Using anatase with a crystallite size of ∼20 nm resulted in phase pure Li4Ti5O12 at the lowest temperature (800 °C). PXRD and TG-DTA results also revealed...

Electrochemical behaviors of wax-coated Li powder/Li 4Ti 5O 12 cells

Science.gov (United States)

Park, Han Eol; Seong, Il Won; Yoon, Woo Young

The wax-coated Li powder specimen was effectively synthesized using the drop emulsion technique (DET). The wax layer on the powder was verified by SEM, Focused Ion Beam (FIB), EDX and XPS. The porosity of a sintered wax-coated Li electrode was measured by linear sweep voltammetry (LSV) and compared with that of a bare, i.e., un-coated Li electrode. The electrochemical behavior of the wax-coated Li powder anode cell was examined by the impedance analysis and cyclic testing methods. The cyclic behavior of the wax-coated Li powder anode with the Li 4Ti 5O 12 (LTO) cathode cell was examined at a constant current density of 0.35 mA cm -2 with the cut-off voltages of 1.2-2.0 V at 25 °C. Over 90% of the initial capacity of the cell remained even after the 300th cycle. The wax-coated Li powder was confirmed to be a stable anode material.

Anomalous magnetoresistance in the spinel superconductor LiTi2O4.

Science.gov (United States)

Jin, K; He, G; Zhang, X; Maruyama, S; Yasui, S; Suchoski, R; Shin, J; Jiang, Y; Yu, H S; Yuan, J; Shan, L; Kusmartsev, F V; Greene, R L; Takeuchi, I

2015-05-20

LiTi2O4 is a unique compound in that it is the only known spinel oxide superconductor. The lack of high quality single crystals has thus far prevented systematic investigations of its transport properties. Here we report a careful study of transport and tunnelling spectroscopy in epitaxial LiTi2O4 thin films. An unusual magnetoresistance is observed which changes from nearly isotropic negative to prominently anisotropic positive as the temperature is decreased. We present evidence that shows that the negative magnetoresistance likely stems from the suppression of local spin fluctuations or spin-orbit scattering centres. The positive magnetoresistance suggests the presence of an orbital-related state, also supported by the fact that the superconducting energy gap decreases as a quadratic function of magnetic field. These observations indicate that the spin-orbital fluctuations play an important role in LiTi2O4 in a manner similar to high-temperature superconductors.

Lithium-Excess Research of Cathode Material Li2MnTiO4 for Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Xinyi Zhang

2015-11-01

Full Text Available Lithium-excess and nano-sized Li2+xMn1−x/2TiO4 (x = 0, 0.2, 0.4 cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD experiments indicate that the obtained main phases of Li2.0MnTiO4 and the lithium-excess materials are monoclinic and cubic, respectively. The scanning electron microscope (SEM images show that the as-prepared particles are well distributed and the primary particles have an average size of about 20–30 nm. The further electrochemical tests reveal that the charge-discharge performance of the material improves remarkably with the lithium content increasing. Particularly, the first discharging capacity at the current of 30 mA g−1 increases from 112.2 mAh g−1 of Li2.0MnTiO4 to 187.5 mAh g−1 of Li2.4Mn0.8TiO4. In addition, the ex situ XRD experiments indicate that the monoclinic Li2MnTiO4 tends to transform to an amorphous state with the extraction of lithium ions, while the cubic Li2MnTiO4 phase shows better structural reversibility and stability.

Improved hydrogen storage properties of LiAlH{sub 4} by mechanical milling with TiF{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Zang, Lei; Cai, Jiaxing; Zhao, Lipeng; Gao, Wenhong; Liu, Jian, E-mail: liujian@nankai.eud.cn; Wang, Yijing

2015-10-25

Dehydrogenation behavior of LiAlH{sub 4} (lithium alanate) admixed with TiF{sub 3} is investigated by pressure-composition-temperature (PCT), fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), differential scanning calorimetry (DSC) and temperature programmed desorption (TPD). The TiF{sub 3} addition enhances kinetics of LiAlH{sub 4} and decreases the decomposition temperature. The LiAlH{sub 4}-2 mol % TiF{sub 3} sample starts to release hydrogen at about 35 °C and the dehydrogenation rate reaches a maximum value at 108.4 °C, compared with 145 °C and 179.9 °C for the as-received LiAlH{sub 4}. As for the dehydrogenation kinetics, the LiAlH{sub 4}-2 mol % TiF{sub 3} sample releases about 7.0 wt % H{sub 2} at 140 °C within 80 min. In comparison, the as-received LiAlH{sub 4} sample releases only 0.8 wt % hydrogen under the same conditions. The existence of proposed catalyst, Al{sub 3}Ti formed in-situ in the process of dehydrogenation, has been confirmed experimentally by XRD measurements. The activation energy of LiAlH{sub 4}-2 mol % TiF{sub 3} composite is deduced to be 66.76 kJ mol{sup −1} and 88.21 kJ mol{sup −1} for the first and second reaction stages of LiAlH{sub 4} dehydrogenation. - Highlights: • TiF{sub 3} considerably enhances the dehydrogenation kinetics of LiAlH{sub 4}. • TiF{sub 3}-doped LiAlH{sub 4} dehydrogenates even at room temperature. • Low activation energy of the dehydrogenation reaction. • Al{sub 3}Ti formed in-situ helps to explain the dehydrogenation mechanism.

Studies of the effects of TiCl{sub 3} in LiBH{sub 4}/CaH{sub 2}/TiCl{sub 3} reversible hydrogen storage system

Energy Technology Data Exchange (ETDEWEB)

Liu Dongan [Ford Motor Company, Research and Advanced Engineering, MD 1170/RIC, Dearborn, MI 48121 (United States); Department of Mechanical Engineering, University of Michigan, 1023 H. H. Dow Building 2350 Hayward Street, Ann Arbor, MI 48109-2125 (United States); Yang Jun, E-mail: jyang27@ford.com [Ford Motor Company, Research and Advanced Engineering, MD 1170/RIC, Dearborn, MI 48121 (United States); Ni Jun [Department of Mechanical Engineering, University of Michigan, 1023 H. H. Dow Building 2350 Hayward Street, Ann Arbor, MI 48109-2125 (United States); Drews, Andy [Ford Motor Company, Research and Advanced Engineering, MD 1170/RIC, Dearborn, MI 48121 (United States)

2012-02-15

Highlights: Black-Right-Pointing-Pointer We systematically studied the effects of TiCl{sub 3} in LiBH{sub 4}/CaH{sub 2}/TiCl{sub 3} hydrogen storage system. Black-Right-Pointing-Pointer It is found that adding 0.25 TiCl{sub 3} produces fully reversible hydrogen absorption and desorption and a lower desorption temperature. Black-Right-Pointing-Pointer LiCl experiences four different states, i.e. 'formed-solid solution-molten solution-precipitation', in the whole desorption process of the system. Black-Right-Pointing-Pointer The incorporation of LiCl into LiBH{sub 4} forms more viscous molten LiBH{sub 4}{center_dot}LiCl, leading to fast kinetics. Black-Right-Pointing-Pointer The precipitation and re-incorporation of LiCl into LiBH{sub 4} lead to a fully reversible complex hydrogen storage system. - Abstract: In the present study, the effects of TiCl{sub 3} on desorption kinetics, absorption/desorption reversibility, and related phase transformation processes in LiBH{sub 4}/CaH{sub 2}/TiCl{sub 3} hydrogen storage system was studied systematically by varying its concentration (x = 0, 0.05, 0.15 and 0.25). The results show that LiCl forms during ball milling of 6LiBH{sub 4}/CaH{sub 2}/xTiCl{sub 3} and that as temperature increases, o-LiBH{sub 4} transforms into h-LiBH{sub 4}, into which LiCl incorporates, forming solid solution of LiBH{sub 4}{center_dot}LiCl, which melts above 280 Degree-Sign C. Molten LiBH{sub 4}{center_dot}LiCl is more viscous than molten LiBH{sub 4}, preventing the clustering of LiBH{sub 4} and the accompanied agglomeration of CaH{sub 2}, and thus preserving the nano-sized phase arrangement formed during ball milling. Above 350 Degree-Sign C, the molten solution LiBH{sub 4}{center_dot}LiCl further reacts with CaH{sub 2}, precipitating LiCl. The main hydrogen desorption reaction is between molten LiBH{sub 4}{center_dot}LiCl and CaH{sub 2} and not between molten LiBH{sub 4} and CaH{sub 2}. This alters the hydrogen reaction thermodynamics and

Crystal structure and stability of LiAlD{sub 4} with TiF{sub 3} additive

Energy Technology Data Exchange (ETDEWEB)

Brinks, H.W. [Department of Physics, Institute for Energy Technology, P.O. Box 40, Kjeller NO-2027 (Norway)]. E-mail: hwbrinks@ife.no; Fossdal, A. [Department of Physics, Institute for Energy Technology, P.O. Box 40, Kjeller NO-2027 (Norway); Fonnelop, J.E. [Department of Physics, Institute for Energy Technology, P.O. Box 40, Kjeller NO-2027 (Norway); Hauback, B.C. [Department of Physics, Institute for Energy Technology, P.O. Box 40, Kjeller NO-2027 (Norway)

2005-07-19

LiAlD{sub 4} samples with TiF{sub 3} additives have been investigated by synchrotron X-ray diffraction, neutron diffraction and a Sieverts-type apparatus. Directly after ball milling there are no signs of any Ti-containing phases, and the unit-cell of LiAlD{sub 4} and Al give no indication of any solid solutions. Hence it is concluded that the Ti is in an amorphous state directly after ball milling. Furthermore, no LiF was observed in the samples. Based on Sieverts-type measurements the plateau pressure at 80 deg C has been proved to be higher than 85 bar. Samples stored in a glove box are slowly desorbed, and after 6 months for a LiAlD{sub 4} + TiF{sub 3} sample, the reaction to LiD + Al is nearly finished.

Mesoporous Spinel Li4Ti5O12 Nanoparticles for High Rate Lithium-ion Battery Anodes

International Nuclear Information System (INIS)

Liu, Weijian; Shao, Dan; Luo, Guoen; Gao, Qiongzhi; Yan, Guangjie; He, Jiarong; Chen, Dongyang; Yu, Xiaoyuan; Fang, Yueping

2014-01-01

Graphical abstract: - Highlights: • Mesoporous Li 4 Ti 5 O 12 nanoparticles were prepared by a simple hydrothermal method. • The mesoporous Li 4 Ti 5 O 12 nanoparticles exhibited a diameter of 40 ± 5 nm and a pore-size distribution of 6 - 8 nm. • Cells with the mesoporous Li 4 Ti 5 O 12 anode showed excellent high rate electrochemical properties. - Abstract: Mesoporous spinel lithium titanate (Li 4 Ti 5 O 12 ) nanoparticles with the diameter of 40 ± 5 nm and the pore-size distribution of 6 - 8 nm were prepared by a simple hydrothermal method. As an anode material for lithium-ion batteries, these spinel Li 4 Ti 5 O 12 mesoporous nanoparticles exhibited desirable lithium storage properties with an initial discharge capacity of 176 mAh g −1 at 1 C rate and a capacity of approximately 145 mAh g −1 after 200 cycles at a high rate of 20 C. These excellent electrochemical properties at high charge/discharge rates are due to the mesoporous nano-scale structures with small size particles, uniform mesopores and larger electrode/electrolyte contact area, which shortens the diffusion path for both electrons and Li + ions, and offers more active sites for Li + insertion-extraction process

Dependency of irradiation damage density on tritium migration behaviors in Li2TiO3

International Nuclear Information System (INIS)

Kobayashi, Makoto; Toda, Kensuke; Oya, Yasuhisa; Okuno, Kenji

2014-01-01

Tritium migration behaviors in Li 2 TiO 3 with the increase of irradiation damage density were investigated by means of electron spin resonance and thermal desorption spectroscopy. The irradiation damages of F + -centers and O − -centers were formed by neutron irradiation, and their damage densities were increased with increasing neutron fluence. Tritium release temperature was clearly shifted toward higher temperature side with increasing neutron fluence, i.e. increasing damage density. The rate determining process for tritium release was also clearly changed depending on the damage density. Tritium release was mainly controlled by tritium diffusion process in crystalline grain of Li 2 TiO 3 at lower neutron fluence. The apparent tritium diffusivity was reduced as the damage density in Li 2 TiO 3 increased due to the introduction of tritium trapping/detrapping sites for diffusing tritium. Then, tritium trapping/detrapping processes began to control the overall tritium release with further damage introductions as the amount of tritium trapping sites increased enough to trap most of tritium in Li 2 TiO 3 . The effects of water vapor in purge gas on tritium release behaviors were also investigated. It was considered that hydrogen isotopes in purge gas would be dissociated and adsorbed on the surface of Li 2 TiO 3 . Then, hydrogen isotopes diffused inward Li 2 TiO 3 would occupy the tritium trapping sites before diffusing tritium reaches to these sites, promoting apparent tritium diffusion consequently. Kinetics analysis of tritium release for highly damaged Li 2 TiO 3 showed that the rate determining process of tritium release was the detrapping process of tritium formed as hydroxyl groups. The rate of tritium detrapping as hydroxyl groups was determined by the kinetic analysis, and was comparable to tritium release kinetics for Li 2 O, LiOH and Li 4 TiO 4 . The dangling oxygen atoms (O − -centers) formed by neutron irradiation would contribute strongly on the

Li_2ZrO_3-coated Li_4Ti_5O_1_2 with nanoscale interface for high performance lithium-ion batteries

International Nuclear Information System (INIS)

Zhang, Han; Liu, Yang; Wang, Ting; Yang, Yang; Shi, Shaojun; Yang, Gang

2016-01-01

Graphical abstract: - Highlights: • Zr doped and Li_2ZrO_3 coated Li_4Ti_5O_1_2 are prepared by a solid-state method. • Zr-doping and LZO coating are positive in improving lithium diffusion ability. • Li_2ZrO_3 coated Li_4Ti_5O_1_2 deliver 168.1 mAh g"−"1 higher than 150.2 mAh g"−"1 of Li_4Ti_5O_1_2. • Li_2ZrO_3 coated Li_4Ti_5O_1_2 remains 162 mAh g"−"1 after 100 cycles. • The lowest D_L_i"+ is 5.97 × 10"−"1"7 and 1.85 × 10"−"1"5 cm"2 s"−"1 of Li_4Ti_5O_1_2 before and after coating. - Abstract: Zr doped sample of Li_4Ti_4_._9_9Zr_0_._0_1O_1_2 (LZTO) and Li_2ZrO_3 (LZO) coated Li_4Ti_5O_1_2 (LTO) are prepared by a solid-state method. The lattice structure of LTO is remained after doping element of Zr and coating layer of LZO. The crystal structure and electrochemical performance of the material are investigated by X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT) and charge-discharge tests, respectively. Zr-doping and LZO coating play the positive role in improving the diffusion ability of lithium cations. LZTO and LZO-LTO show much improved specific capacity and rate capability compared with pristine sample of LTO. LZO-LTO has the smallest voltage differential (ΔV) of the redox peaks because the coating of Li_2ZrO_3 is helpful for the diffusion ability of lithium ions during charge/discharge processes. LZTO and LZO-LTO as electrode deliver the initial capacities of 164.8, 168.1 mAh g"−"1, respectively, which are much higher than 150.2 mAh g"−"1 of intrinsic sample of LTO. Even at the current density of 2 A g"−"1, LTZO and LZO-LTO offer capacity of 96 and 106 mAh g"−"1, which are much higher than 33 mAh g"−"1 of LTO. The improved electrochemical performance is attributed to the improved diffusion ability of lithium. During the whole discharge process, the lowest value of LTO is 5.97 × 10"−"1"7 cm"2 s"−"1 that is

First-principles calculated decomposition pathways for LiBH4 nanoclusters

Science.gov (United States)

Huang, Zhi-Quan; Chen, Wei-Chih; Chuang, Feng-Chuan; Majzoub, Eric H.; Ozoliņš, Vidvuds

2016-05-01

We analyze thermodynamic stability and decomposition pathways of LiBH4 nanoclusters using grand-canonical free-energy minimization based on total energies and vibrational frequencies obtained from density-functional theory (DFT) calculations. We consider (LiBH4)n nanoclusters with n = 2 to 12 as reactants, while the possible products include (Li)n, (B)n, (LiB)n, (LiH)n, and Li2BnHn; off-stoichiometric LinBnHm (m ≤ 4n) clusters were considered for n = 2, 3, and 6. Cluster ground-state configurations have been predicted using prototype electrostatic ground-state (PEGS) and genetic algorithm (GA) based structural optimizations. Free-energy calculations show hydrogen release pathways markedly differ from those in bulk LiBH4. While experiments have found that the bulk material decomposes into LiH and B, with Li2B12H12 as a kinetically inhibited intermediate phase, (LiBH4)n nanoclusters with n ≤ 12 are predicted to decompose into mixed LinBn clusters via a series of intermediate clusters of LinBnHm (m ≤ 4n). The calculated pressure-composition isotherms and temperature-pressure isobars exhibit sloping plateaus due to finite size effects on reaction thermodynamics. Generally, decomposition temperatures of free-standing clusters are found to increase with decreasing cluster size due to thermodynamic destabilization of reaction products.

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...

Fabrication of Li{sub 2}TiO{sub 3} pebbles using PVA–boric acid reaction for solid breeding materials

Energy Technology Data Exchange (ETDEWEB)

Park, Yi-Hyun, E-mail: yhpark@nfri.re.kr; Cho, Seungyon; Ahn, Mu-Young

2014-12-15

Highlights: • Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method. • Boron was used as hardening agent of PVA and completely removed during sintering. • Microstructure of fabricated Li{sub 2}TiO{sub 3} pebble was exceptionally homogeneous. • Suitable process conditions for high-quality Li{sub 2}TiO{sub 3} pebble were summarized. - Abstract: Lithium metatitanate (Li{sub 2}TiO{sub 3}) is a candidate breeding material of the Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM). The breeding material is used in pebble-bed form to reduce the uncertainty of the interface thermal conductance. In this study, Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by the slurry droplet wetting method using the cross-linking reaction between polyvinyl alcohol (PVA) and boric acid. The effects of fabrication parameters on the shaping of Li{sub 2}TiO{sub 3} green body were investigated. In addition, the basic characteristics of the sintered pebble were also evaluated. The shape of Li{sub 2}TiO{sub 3} green bodies was affected by slurry viscosity, PVA content and boric acid content. The grain size and average crush load of sintered Li{sub 2}TiO{sub 3} pebble were controlled by the sintering time. The boron was completely removed during the final sintering process.

In-pile test of Li{sub 2}TiO{sub 3} pebble bed with neutron pulse operation

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, K. E-mail: tsuchiya@oarai.jaeri.go.jp; Nakamichi, M.; Kikukawa, A.; Nagao, Y.; Enoeda, M.; Osaki, T.; Ioki, K.; Kawamura, H

2002-12-01

Lithium titanate (Li{sub 2}TiO{sub 3}) is one of the candidate materials as tritium breeder in the breeding blanket of fusion reactors, and it is necessary to show the tritium release behavior of Li{sub 2}TiO{sub 3} pebble beds. Therefore, a blanket in-pile mockup was developed and in situ tritium release experiments with the Li{sub 2}TiO{sub 3} pebble bed were carried out in the Japan Materials Testing Reactor. In this study, the relationship between tritium release behavior from Li{sub 2}TiO{sub 3} pebble beds and effects of various parameters were evaluated. The (R/G) ratio of tritium release (R) and tritium generation (G) was saturated when the temperature at the outside edge of the Li{sub 2}TiO{sub 3} pebble bed became 300 deg. C. The tritium release amount increased cycle by cycle and saturated after about 20 pulse operations.

Simultaneous quantification of Li, Ti and O in Lithium titanate by particle induced gamma-ray emission using 8 MeV proton beam

International Nuclear Information System (INIS)

Chhillar, Sumit; Acharya, R.; Tripathi, R.; Sodaye, S.; Sudarshan, K.; Pujari, P.K.; Rout, P.C.; Mukherjee, S.K.

2014-01-01

Simultaneous quantification of Li, Ti and O in lithium titanate (Li 2 TiO 3 ) is difficult by particle induced gamma-ray emission (PIGE) using low energy (∼4 MeV) proton beam. PIGE method using 8 MeV proton beam at BARC-TIFR pelletron facility was standardized for compositional characterization of sol-gel synthesized Li 2 TiO 3 by determining concentrations of Li, Ti and O simultaneously. Thick targets of samples, synthetic samples and standards were prepared in graphite matrix. Beam current variation was normalized by Rutherford Backscattering Spectrometry (RBS) using a thin gold foil. The gamma-rays of 478, 981 and 6129 keV were measured from 7 Li(p, p'γ) 7 Li, 48 Ti(p, p'γ) 48 Ti and 16 O(p, p'γ) 16 O nuclear reactions for quantification of Li, Ti and O, respectively. The method was validated by determining concentrations of Li, TI and O in a synthetic sample. (author)

Effect of Carbon Coating on Li4TiO12 of Anode Material for Hybrid Capacitor.

Science.gov (United States)

Lee, Jong-Kyu; Lee, Byung-Gwan; Yoon, Jung-Rag

2015-11-01

The carbon-coated Li4Ti5O12 of anode material for hybrid capacitor was prepared by controlling carbonization time at 700 degrees C in nitrogen. With increasing of carbonization time, the discharge capacity and capacitance were decreased, while the equivalent series resistance was not changed remarkably. The rate capability and cycle performance of carbon-coated Li4Ti5O12 were larger than that of Li4Ti5O12. Carbon coating improved conductivity as well as Li-ion diffusion, and thus also resulted in good rate capabilities and cycle stability. The effects of carbon coating on the gas generation of hybrid capacitor were also discussed.

3D inverse-opal structured Li4Ti5O12 Anode for fast Li-Ion storage capabilities

Science.gov (United States)

Kim, Dahye; Quang, Nguyen Duc; Hien, Truong Thi; Chinh, Nguyen Duc; Kim, Chunjoong; Kim, Dojin

2017-11-01

Since the demand for high power Li-ion batteries (LIBs) is increasing, spinel-structured lithium titanate, Li4Ti5O12 (LTO), as the anode material has attracted great attention because of its excellent cycle retention, good thermal stability, high rate capability, and so on. However, LTO shows relatively low conductivity due to empty 3 d orbital of Ti4+ state. Nanoscale architectures can shorten electron conduction path, thus such low electronic conductivity can be overcome while Li+ can be easily accessed due to large surface area. Herein, three dimensional bicontinuous LTO electrodes were prepared via close-packed self-assembly with polystyrene (PS) spheres followed by removal of them, which leads to no blockage of Li+ ion transportation pathways as well as fast electron conduction. 3D bicontinuous LTO electrodes showed high-rate lithium storage capability (103 mAh/g at 20 C), which is promising as the power sources that require rapid electrochemical response.[Figure not available: see fulltext.

The dehydrogenation performance and reaction mechanisms of Li{sub 3}AlH{sub 6} with TiF{sub 3} additive

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu-Sheng [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yao; Sun, Li-Xian; Zhang, Jian; Zhao, Jun-Ning [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Xu, Fen [Faculty of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Huang, Feng-Lei [State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China)

2010-05-15

For Li{sub 3}AlH{sub 6} prepared by mechanical milling method, the dissociation reaction enthalpy and activation energy are calculated to be 22.1 kJ mol{sup -1} H{sub 2} and 133.7 {+-} 2.7 kJ mol{sup -1}, respectively. The dehydrogenation performance of Li{sub 3}AlH{sub 6} is greatly enhanced by TiF{sub 3} additive, especially in the kinetic behaviors. For the Li{sub 3}AlH{sub 6} + 10 mol% TiF{sub 3} sample, the starting temperature of dehydrogenation is obviously decreased by 60 C from that of pure Li{sub 3}AlH{sub 6} (190 C), and 3.0 wt.% H{sub 2} may be released within 1000 s at 120 C under an initial vacuum. With the amount of TiF{sub 3} increasing, the starting temperature decreases and the kinetics improves due to the decrease in the activation energy. The X-ray diffraction (XRD) together with thermogravimetric analysis (TGA) results show that there are three mechanochemical reactions involved during milling: i) Li{sub 3}AlH{sub 6} + TiF{sub 3} {yields} 3 LiF + Al + Ti + 3H{sub 2}, ii) Ti + H{sub 2} {yields} TiH{sub 2}, iii) 3 Al + Ti {yields} Al{sub 3}Ti. The in-situ formed Ti species (TiH{sub 2} and Al{sub 3}Ti) co-catalyze the thermal dehydrogenation of Li{sub 3}AlH{sub 6}. (author)

Electrochemical properties of spinel Li4Ti5O12 nanoparticles\

Czech Academy of Sciences Publication Activity Database

Senna, M.; Fabián, M.; Kavan, Ladislav; Zukalová, Markéta; Briančin, J.; Turianicová, E.; Bottke, P.; Wilkening, M.; Šepelák, V.

2016-01-01

Roč. 20, č. 10 (2016), s. 2673-2683 ISSN 1432-8488 R&D Projects: GA ČR GA15-06511S Institutional support: RVO:61388955 Keywords : Li4Ti5O12 * reactive precursor * Li-ion battery Subject RIV: CG - Electrochemistry Impact factor: 2.316, year: 2016

Solid-state synthesis of Li{sub 4}Ti{sub 5}O{sub 12} whiskers from TiO{sub 2}-B

Energy Technology Data Exchange (ETDEWEB)

Yao, Wenjun [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); Zhuang, Wei [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); College of Biotechnology and Pharmaceutical Engineering, National Engineering Technique Research Center for Biotechnology, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816 (China); Ji, Xiaoyan [Division of Energy Science/Energy Engineering, Luleå University of Technology, Luleå 97187 Sweden (Sweden); Chen, Jingjing; Lu, Xiaohua [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China); Wang, Changsong, E-mail: wcs@njtech.edu.cn [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009 (China)

2016-03-15

Highlights: • The Li{sub 4}Ti{sub 5}O{sub 12} whiskers were synthesized from TiO{sub 2}-B whiskers via a solid state reaction. • The TiO{sub 2}-B crystal structure for lithium diffusion is easier than anatase. • The separated diffusion and reaction process is crucial for the solid-state syntheses of Li{sub 4}Ti{sub 5}O{sub 12} whiskers. - Abstract: In this work, Li{sub 4}Ti{sub 5}O{sub 12} (LTO) was synthesized from the precursors of TiO{sub 2}-B and anatase whiskers, respectively. The synthesized LTO whiskers from TiO{sub 2}-B whiskers via a solid state reaction at 650 °C have a high degree of crystallinity with an average diameter of 300 nm. However, when anatase whiskers were used as the precursor, only particle morphology LTO was produced at 750 °C. The further analysis of the precursors, the intermediate products and the final products reveal that the crystal structure of the anatase hinders the diffusion of lithium, leading to a typical reaction–diffusion process. Under this condition, only particle morphology LTO can be produced. However, the crystal structure of the TiO{sub 2}-B is easy for lithium diffusion and the process is performed in two separated steps (i.e., diffusion and reaction), which makes it possible to decrease the solid-state reaction temperature down to 650 °C and then maintain the morphologies of whiskers.

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

Characterization of Li4Ti5O12 and LiMn2O4 spinel materials treated with aqueous acidic solutions

NARCIS (Netherlands)

Simon, D.R.

2007-01-01

In this thesis an investigation of two spinel materials, Li4Ti5O12 and LiMn2O4 used for Li-ion battery applications is performed interms of formation and reactivity towards acidic solutions. Subsequent characterizations such as structural, magnetic, chemical, and electrochemical characterizations

Preparation of β-Li{sub 2}TiO{sub 3} pebbles by a modified indirect wet chemistry method

Energy Technology Data Exchange (ETDEWEB)

Yu, Cheng-Long, E-mail: johnyucl@aliyun.com [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); Research Laboratory of Hydrothermal Chemistry, Faculty of Science, The Kochi University, Kochi 780-8520 (Japan); Wang, Fei; Zhang, Ai-Lin; Gao, Dan-Peng; Cao, Shu-Yao [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); Guo, Ying-Yan [College of Resources and Environment, Shaanxi University of Science & Technology, Xi’an 710021 (China); Hui, Huai-Bin [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); Technology Research Institute, Technical Center at Dongfeng Commercial Vehicle Company Limited, Wuhan 430056 (China); Hao, Xin [School of Management, Shaanxi University of Science & Technology, Xi’an 710021 (China); Wang, Dao-Yi [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Faculty of Science, The Kochi University, Kochi 780-8520 (Japan)

2015-12-15

Graphical abstract: β-Li{sub 2}TiO{sub 3} pebbles with about 1.56 mm in diameter, a better sphericity of 1.02 and relative sintered density of 95.8%T.D. are successfully fabricated when sintered at 1100 °C for 6 h in ambient conditions. - Highlights: • β-Li{sub 2}TiO{sub 3} powders via hydrothermal method are used as raw materials. • A mixture of the acetone and carbon tetrachloride bath is used. • The wet gel pebbles can be fabricated at room temperature. - Abstract: β-Li{sub 2}TiO{sub 3} pebbles were fabricated by a modified indirect wet chemistry method. The first feature lies in that β-Li{sub 2}TiO{sub 3} powders via hydrothermal method were used as raw materials. The second one lies in that a mixture of the acetone and carbon tetrachloride was used for formation and aging of the pebbles at room temperature. The phase identification of the β-Li{sub 2}TiO{sub 3} sintered pebbles was conducted by the X-ray Diffraction analysis. The morphology of the sintered β-Li{sub 2}TiO{sub 3} pebbles was observed by Field Emission Scanning Electron Microscope. The experimental results show that the β-Li{sub 2}TiO{sub 3} pebbles with about 1.56 mm in diameter, a better sphericity of 1.02 and relative sintered density of 95.8%T.D. are successfully fabricated when sintered at 1100 °C for 6 h in ambient conditions. The grains in the pebbles are polyhedral brick-shaped, and homogeneous in size distribution. The morphology evolution and relative density of the β-Li{sub 2}TiO{sub 3} pebbles are governed by the sintering temperature, between 1050 °C and 1150 °C. More homogeneous in grain size, less porosity, and higher densification of the β-Li{sub 2}TiO{sub 3} pebbles can be obtained at 1100 °C.

Multi-walled carbon nanotubes functionalized by carboxylic groups: Activation of TiO{sub 2} (anatase) and phosphate olivines (LiMnPO{sub 4}; LiFePO{sub 4}) for electrochemical Li-storage

Energy Technology Data Exchange (ETDEWEB)

Kavan, Ladislav; Zukalova, Marketa [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-18223 Prague 8 (Czech Republic); Bacsa, Revathi; Tunckol, Meltem; Serp, Philippe [Laboratoire de Chimie de Coordination, UPR CNRS 8241, composante ENSIACET, Universite de Toulouse UPS-INP-LCC 4, Allee Emile Monso, BP 74233, 31432, Toulouse (France); Zakeeruddin, Shaik M.; Le Formal, Florian; Graetzel, Michael [Laboratoire de Photonique et Interfaces, EPFL, Ecublens, CH-1015 Lausanne (Switzerland)

2010-08-15

Multi-walled carbon nanotubes functionalized by carboxylic groups, exhibit better affinity towards TiO{sub 2} (P90, Degussa) as compared to that of pristine nanotubes. Also the electrochemical performance of TiO{sub 2} is improved by nanotube networking, but the Li-storage capacity of TiO{sub 2} is unchanged. Whereas the composite of TiO{sub 2} with non-functionalized nanotubes demonstrates simple superposition of the behavior of pure components, the composite with functionalized nanotubes shows unique faradaic pseudocapacitance which is specific for this composite only. The surface functionalization of nanotubes enhances charge storage capacity and reversibility of a composite with LiMnPO{sub 4} (olivine), but mediates also the electrolyte breakdown at potentials >4.2 V. Whereas the electrochemical activation of LiMnPO{sub 4} (olivine) by functionalized nanotubes is quite modest, excellent performance was found for LiFePO{sub 4} (olivine) in composite materials containing only 2 wt% of functionalized nanotubes. (author)

A novel layered titanoniobate LiTiNbO5: topotactic synthesis and electrochemistry versus lithium.

Science.gov (United States)

Colin, J-F; Pralong, V; Caignaert, V; Hervieu, M; Raveau, B

2006-09-04

A new layered titanoniobate, LiTiNbO5, an n = 2 member of the A(x)M(2n)O(4n+2) family, has been synthesized using a molten salt reaction between HTiNbO5 and an eutectic "LiOH/LiNO3". This compound crystallizes in the P2(1)/m space group with a = 6.41 A, b = 3.77 A, c = 8.08 A, and beta = 92 degrees . It exhibits |TiNbO5|(infinity) layers similar to HTiNbO5, but differs from the latter by a "parallel configuration" of its |TiNbO6|(infinity) ribbons between the two successive layers. The topotactic character of the reaction suggests that exfoliation plays a prominent role in the synthesis of this new form. This new phase intercalates reversibly 0.8 lithium through a first-order transformation leading to a capacity of 94 mAh/g at a potential of 1.67 V vs Li/Li+.

Zr doping effect with low-cost solid-state reaction method to synthesize submicron Li4Ti5O12 anode material

Science.gov (United States)

Seo, Inseok; Lee, Cheul-Ro; Kim, Jae-Kwang

2017-09-01

To improve the electrochemical properties, fine Zr-doping Li4Ti5O12 anode materials for rechargeable lithium batteries with a uniform particle size distribution were synthesized by a modified solid-state reaction using fine Li2CO3 and TiO2 (anatase) powders as precursors with a Li:Ti molar ratio of 4:5. The use of fine Li2CO3 and TiO2 (anatase) powders as precursors prevented the formation of ZrO2 at 0.1 mol Zr-doping. XRD analysis revealed that the substitution of Zr for Ti leads to the increase of lattice parameters, allowing improved Li diffusion. The discharge capacity retention increased slightly with Zr-doping and the 0.1 mol Zr-doped Li4Ti5O12 electrode achieved 99% retention of discharge capacity.

Phototransfered thermoluminescence for dose reassessment in LiF:mg,ti , LiF: mg,Cu,p TL detectors

International Nuclear Information System (INIS)

Rodriguez Otazo, M.; Baly, L.

2001-01-01

Phototransfered Thermoluminescence (PTTL) from LiF:Mg,Ti (TLD-100) and LiF: Mg,Cu,P (GR-200) was studied at different conditions using different sources of UV light for dose reassessment purposes. The TL dosimeters were irradiated with 137Cs in the range 2 mGy to 100 mGy. The convenience of using PTTL for dose reassessment was analyzed

Determination of kinetic parameters in the systems Li0.5La0.5TiO3 and Li0.5La0.5TiO3/PANI by GITT (Galvanostatic intermittent titration technique)

International Nuclear Information System (INIS)

Pérez Cappe, Eduardo; Mosqueda Laffita, Yodalgis; Milian Pila, Carlos R.

2008-01-01

Full text: Oxides belonging to the family Li 3x La 2/3-x TiO 3 have been reported as materials of a high Ionic conductivity and a poor electronic conductivity at room temperature. The combination of these materials with other polymer in nature, such as polyaniline (PANI), of proven electronic properties, allows to obtain potentially applicable material in rechargeable Li. In this context the study of diffusive phenomena are of vital importance. A technical electrochemistry of intermittent rating (GITT), which combines state transient measurements and stationary, for the calculation of kinetic parameters in the Li 0.5 La 0.5 TiO 3 system and a composite comprising this oxide and PANI (Li 0.5 La 0.5 TiO 3 /PANI) in its conductive phase (emeraldine) is used in this work. Interesting considerations concerning shows the calculation of the numbers of ionic and electronic transport, necessary for the determination of coefficients of electronic dissemination. (author)

Insight into effects of graphene in Li4Ti5O12/carbon composite with high rate capability as anode materials for lithium ion batteries

International Nuclear Information System (INIS)

Ding, Y.; Li, G.R.; Xiao, C.W.; Gao, X.P.

2013-01-01

Li 4 Ti 5 O 12 /carbon composites have shown promising high rate capability as anode materials for lithium ion batteries. In this paper, unique effects of graphene in Li 4 Ti 5 O 12 /carbon composites on electrochemical performances are focused by means of comparing Li 4 Ti 5 O 12 /graphene with Li 4 Ti 5 O 12 /conductive carbon black (CCB) and Li 4 Ti 5 O 12 . The investigated anode materials are synthesized by a facile hydrothermal method. The amount of graphene or CCB in the Li 4 Ti 5 O 12 /carbon composites is about 3 wt% measured by thermogravimetric (TG) analysis. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that Li 4 Ti 5 O 12 /graphene consists of small sized Li 4 Ti 5 O 12 nanocrystals supported on graphene nanosheets, while Li 4 Ti 5 O 12 /CCB comprises Li 4 Ti 5 O 12 nanocrystal aggregates coated nearly by graphited carbon. The electrochemical performances of these samples as anode materials for lithium ion batteries are investigated by galvanostatic charge–discharge method. Li 4 Ti 5 O 12 /graphene provides a superior rate capability. At the high current density of 1600 mA g −1 , the reversible capacity after 200 cycles is still more than 120 mAh g −1 , which is about 40% higher than that of Li 4 Ti 5 O 12 /CCB. Cyclic voltammetry (CV) demonstrates that stronger pseudocapacitive effect occurs on Li 4 Ti 5 O 12 /graphene than on Li 4 Ti 5 O 12 /CCB. This derived from the structure features that graphene-supported small Li 4 Ti 5 O 12 nanocrystals provide more surface active sites for the lithium ion insertion/extraction. The strong pseudocapacitive effect is responsible for the improvements of capacity and high-rate capability. Further, electrochemical impedance spectra (EIS) show that Li 4 Ti 5 O 12 /graphene electrode have lower charge transfer resistance and smaller diffusion impedance, indicating the obvious advantages in electrode kinetics over Li 4 Ti 5 O 12 and Li 4 Ti 5 O 12

Study of Optically Stimulated Luminescence of LiF:Mg,Ti for beta and gamma dosimetry

International Nuclear Information System (INIS)

Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Letícia L.

2013-01-01

Modern advances in radiation medicine – radiodiagnosis, radiotherapy and interventional radiography – each present dosimetry challenges for the medical physicist that did not exist previously. In all of these areas a constant balance has to be made between the treatment necessary to destroy the tumor and the unnecessary exposure of healthy tissue. Innovative applications of OSL dosimetry are now appearing in each of these areas to help the medical physicist and oncologist design the most effective, and least deleterious, treatment for their patients. High sensitivity, precise delivery of light, fast readout times, simpler readers and easier automation are the main advantages of OSL in comparison with TLD. This work aimed to study the application of OSL technique using lithium fluoride dosimeters doped with magnesium and titanium (LiF:Mg,Ti) for application in beta and gamma dosimetry. -- Highlights: •Study of Optically Stimulated Luminescence of LiF:Mg,Ti and microLiF:Mg,Ti. •OSL response of TLD-100 dosimeters to beta and gamma radiation. •Analysis of repeatability and lowest levels of detection of detectors LiF:Mg,Ti

Carbon coated Li{sub 4}Ti{sub 5}O{sub 12} nanorods as superior anode material for high rate lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Luo, Hongjun; Shen, Laifa; Rui, Kun; Li, Hongsen; Zhang, Xiaogang, E-mail: azhangxg@nuaa.edu.cn

2013-09-25

Highlights: •A novel approach has been developed to fabricate 1D Li{sub 4}Ti{sub 5}O{sub 12}/C nanorods by a wet-chemical route. •Carbon coating layer effectively restrict the particle growth and enhance electronic conductivity. •The Li{sub 4}Ti{sub 5}O{sub 12}/C nanorods exhibit remarkable rate capability and long cycle life. -- Abstract: We describe a novel approach for the synthesis of carbon coated Li{sub 4}Ti{sub 5}O{sub 12} (Li{sub 4}Ti{sub 5}O{sub 12}/C) nanorods for high rate lithium ion batteries. The carbon coated TiO{sub 2} nanotubes using the glucose as carbon source are first synthesized by hydrothermal treatment. The commercial anatase TiO{sub 2} powder is immersed in KOH sulotion and subsequently transforms into Li{sub 4}Ti{sub 5}O{sub 12}/C in LiOH solution under hydrothermal condition. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption/desorption and Raman spectra are performed to characterize their morphologies and structures. Compared with the pristine Li{sub 4}Ti{sub 5}O{sub 12}, one-dimensional (1D) Li{sub 4}Ti{sub 5}O{sub 12}/C nanostructures show much better rate capability and cycling stability. The 1D Li{sub 4}Ti{sub 5}O{sub 12}/C architectures effectively restrict the particle growth and enhance their electronic conductivity, enabling fast ion and electron transport.

Synthesis and electrochemical properties of Ti4+ doped Li3-xFe2-xTix(PO4)3/C cathode materials

International Nuclear Information System (INIS)

Liu Zhanqiang; Huang Fuqiang; Sun Junkang

2011-01-01

Highlights: → Li 3-x Fe 2-x Ti x (PO 4 ) 3 /C composite cathodes were prepared by ball-milling method. Ti-doping can improve the electrochemical property of Li 3 Fe 2 (PO 4 ) 3 . → The optimized doping level was found to be x = 0.2. → The second phase of LiTi 2 (PO 4 ) 3 will emerge if the doping level higher than 0.2. - Abstract: Li 3-x Fe 2-x Ti x (PO 4 ) 3 /C (x = 0-0.4) cathodes designed with Fe doped by Ti was studied. Both Li 3 Fe 2 (PO 4 ) 3 /C (x = 0) and Li 2.8 Fe 1.8 Ti 0.2 (PO 4 ) 3 /C (x = 0.2) possess two plateau potentials of Fe 3+ /Fe 2+ couple (around 2.8 V and 2.7 V vs. Li + /Li) upon discharge observed from galvanostatic charge/discharge and cyclic voltammetry. Li 2.8 Fe 1.8 Ti 0.2 (PO 4 ) 3 /C has higher reversibility and better capacity retention than that of the undoped Li 3 Fe 2 (PO 4 ) 3 /C. A much higher specific capacity of 122.3 mAh/g was obtained at C/20 in the first cycle, approaching the theoretical capacity of 128 mAh/g, and a capacity of 100.1 mAh/g was held at C/2 after the 20th cycle.

Effects of the LiFePO4 content and the preparation method on the properties of (LiFePO4+AC/Li4Ti5O12 hybrid battery–capacitors

Directory of Open Access Journals (Sweden)

XUE BU HU

2010-09-01

Full Text Available Two composite cathode materials containing LiFePO4 and activated carbon (AC were synthesized by an in-situ method and a direct mixing technique, which are abbreviated as LAC and DMLAC, respectively. Hybrid battery–capacitors LAC/Li4Ti5O12 and DMLAC/Li4Ti5O12 were then assembled. The effects of the content of LiFePO4 and the preparation method on the cyclic voltammograms, the rate of charge–discharge and the cycle performance of the hybrid battery–capacitors were investigated. The results showed the overall electrochemical performance of the hybrid battery–capacitors was the best when the content of LiFePO4 in the composite cathode materials was in the range from 11.8 to 28.5 wt. %, while the preparation method had almost no impact on the electrochemical performance of the composite cathodes and hybrid battery–capacitors. Moreover, the hybrid battery–capacitor devices had a good cycle life performance at high rates. After 1000 cycles, the capacity loss of the DMLAC/Li4Ti5O12 hybrid battery–capacitor device at 4C was no more than 4.8 %. Moreover, the capacity loss would be no more than 9.6 % after 2000 cycles at 8C.

Dual Functions of Carbon in Li(sub4)Ti(sub5)O(sub12)/C Microspheres

CSIR Research Space (South Africa)

Wen, L

2015-01-01

Full Text Available Spinel Li(sub4)Ti(sub5)O(sub12) has become an alternative material to replace graphite anodes in terms of solving safety issues and improving battery life-time. Unfortunately, as Li(sub4)Ti(sub5)O(sub12) is an insulator, the low electrical...

Solid-state synthesis of Li{sub 4}Ti{sub 5}O{sub 12} for high power lithium ion battery applications

Energy Technology Data Exchange (ETDEWEB)

Han, Seung-Woo [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Ryu, Ji Heon [Graduate School of Knowledge-Based Technology and Energy, Korea Polytechnic University, Siheung 429-793 (Korea, Republic of); Jeong, Joayoung [Cell Precedence Development Group, Samsung SDI, Yongin 446-577 (Korea, Republic of); Yoon, Dang-Hyok, E-mail: dhyoon@ynu.ac.kr [School of Materials Science and Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of)

2013-09-05

Highlights: •High energy milling using 0.30 and 0.45 mm beads for Li{sub 4}Ti{sub 5}O{sub 12} synthesis. •Synthesis of 162 nm-sized pure Li{sub 4}Ti{sub 5}O{sub 12} by solid-state reaction. •Spray drying using fine starting materials to confer paste tackiness. •High capacity of 174 mAh/g and adequate rate properties for high power LIBs applications. -- Abstract: Li{sub 4}Ti{sub 5}O{sub 12} was synthesized by a solid-state reaction between Li{sub 2}CO{sub 3} and anatase TiO{sub 2} for applications to high power lithium ion batteries. The starting materials underwent 6 h of high energy milling using ZrO{sub 2} beads with two different sizes, 0.30 and 0.45 mm. The smaller ZrO{sub 2} beads resulted in finer starting materials. Spray drying was also performed on the 0.30 mm beads-treated particles to enhance the screen printability of a paste containing this powder. The finer starting materials showed a pure 162 nm-sized Li{sub 4}Ti{sub 5}O{sub 12} due to the decreased diffusion length for a solid-state reaction, whereas the 0.45 mm beads-treated starting materials resulted in a 242 nm-sized Li{sub 4}Ti{sub 5}O{sub 12} phase containing 2 wt.% of rutile TiO{sub 2} that had transformed from the anatase phase during heat treatment at 800 °C for 3 h. The finer Li{sub 4}Ti{sub 5}O{sub 12} showed higher charge capacity and better charge/discharge rates than the coarser particles, which highlights the importance of the primary particle size on the electrochemical properties of Li{sub 4}Ti{sub 5}O{sub 12} for high power applications. The fine Li{sub 4}Ti{sub 5}O{sub 12} particles had a discharge capacity of 174 mAh/g at 0.1 C and capacity retention of 80% at 10.0 C.

Nanostructured lithium titanates (Li4Ti5O12) for lithium-ion batteries

CSIR Research Space (South Africa)

Wen, L

2016-07-01

Full Text Available Nanostructured lithium titanates (Li(sub4)Ti(sub5)O(sub12)) have been intensively investigated as anode materials of Li-ion batteries due to their many advantages, such as excellent performance, outstanding safety, and excellent cycle life...

Enhanced Hydrogen Storage Properties and Reversibility of LiBH4 Confined in Two-Dimensional Ti3C2.

Science.gov (United States)

Zang, Lei; Sun, Weiyi; Liu, Song; Huang, Yike; Yuan, Huatang; Tao, Zhanliang; Wang, Yijing

2018-05-30

LiBH 4 is of particular interest as one of the most promising materials for solid-state hydrogen storage. Herein, LiBH 4 is confined into a novel two-dimensional layered Ti 3 C 2 MXene through a facile impregnation method for the first time to improve its hydrogen storage performance. The initial desorption temperature of LiBH 4 is significantly reduced, and the de-/rehydrogenation kinetics are remarkably enhanced. It is found that the initial desorption temperature of LiBH 4 @2Ti 3 C 2 hybrid decreases to 172.6 °C and releases 9.6 wt % hydrogen at 380 °C within 1 h, whereas pristine LiBH 4 only releases 3.2 wt % hydrogen under identical conditions. More importantly, the dehydrogenated products can partially rehydrogenate at 300 °C and under 95 bar H 2 . The nanoconfined effect caused by unique layered structure of Ti 3 C 2 can hinder the particles growth and agglomeration of LiBH 4 . Meanwhile, Ti 3 C 2 could possess superior effect to destabilize LiBH 4 . The synergetic effect of destabilization and nanoconfinement contributes to the remarkably lowered desorption temperature and improved de-/rehydrogenation kinetics.

Chrystal structure properties of Al-doped Li{sub 4}Ti{sub 5}O{sub 12} synthesized by solid state reaction method

Energy Technology Data Exchange (ETDEWEB)

Sandi, Dianisa Khoirum, E-mail: dianisa875@gmail.com; Suryana, Risa, E-mail: rsuryana@staff.uns.ac.id [Department of Physics, Faculty of Mathematics and Natural Sciences, Sebelas Maret University (Indonesia); Priyono, Slamet, E-mail: slam013@lipi.go.id [Physics Research Center (P2F)-LIPI, Puspiptek Area, Serpong, Tangerang (Indonesia)

2016-02-08

This research aim is to analyze the effect of Aluminum (Al) doping in the structural properties of Al-doped Li{sub 4}Ti{sub 5}O{sub 12} as anode in lithium ion battery. Al-doped Li{sub 4}Ti{sub 5}O{sub 12} powders were synthesized by solid state reaction method. LiOH.H{sub 2}O, TiO{sub 2}, and Al{sub 2}O{sub 3} were raw materials. These materials were milled for 15 h, calcined at temperature of 750{sup o}C and sintered at temperature of 800{sup o}C. Mole percentage of doping Al (x) was varied at x=0; x=0.025; and x =0.05. Al-doped Li{sub 4}Ti{sub 5}O{sub 12} powders were synthesized by solid state reaction method. X-ray diffraction was employed to determine the structure of Li{sub 4}Ti{sub 5}O{sub 12}. The PDXL software was performed on the x-ray diffraction data to estimate the phase percentage, the lattice parameter, the unit cell volume, and the crystal density. Al-doped Li{sub 4}Ti{sub 5}O{sub 12} has cubic crystal structure. Al-doping at x=0 and x=0.025 does not change the phase as Li{sub 4}Ti{sub 5}O{sub 12} while at x=0.050 the phase changes to the LiTiAlO{sub 4}. The diffraction patterns show that the angle shifted to the right as the increase of x which indicated that Al substitute Ti site. Percentage of Li{sub 4}Ti{sub 5}O{sub 12} phase at x=0 and x=0.025 was 97.8% and 96.8%, respectively. However, the lattice parameters, the unit cell volume, and the crystal density does not change significantly at x=0; x=0.025; and x=0.050. Based on the percentage of Li{sub 4}Ti{sub 5}O{sub 12} phase, the Al-doped Li at x=0 and x=0.025 is promising as a lithium battery anode.

Comparison of characteristics of LiF:Mg,Ti e LiF:Mg,Cu,P thermoluminescent dosemeters; Comparacao das caracteristicas dos dosimetros termoluminescentes LiF:Mg,Ti e LiF:Mg,Cu,P

Energy Technology Data Exchange (ETDEWEB)

Pereira, M.S.; Filipov, D., E-mail: dfilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR/DAFIS), Curitiba, PR (Brazil). Departamento Academicao de Fisica; Schelin, H.R. [Instituto de Pesquisa Pele Pequeno Principe (IPPPP), Curitiba, PR (Brazil)

2014-07-01

The aim of the current study was to compare the thermoluminescent dosimeters LiF:Mg,Ti (TLD-100) and LiF:Mg,Cu,P (MCP) data, which were acquired by the Federal Technological University - Parana. Tests were realized, for this purpose, such as: sensitivity (only one MCP TLD did not present results within the limit range), linearity (whose MCP result was better than the TLD-100 one), energy dependence (TLD-100 presented lower variation than MCP TLD) and reproducibility (whose TLD-100 results were better than the MCP ones). The results from both dosimeters show that these TLDs attend radiodiagnostic dosimetry criteria, however MCP had more satisfactory results. (author)

Adsorption of Ti on LiAlH4 surfaces studied by band structure calculations

International Nuclear Information System (INIS)

Loevvik, O.M.

2004-01-01

LiAlH 4 is a potential light-weight hydrogen storage material if hydrogenation can be made reversible. In NaAlH 4 this may be done by adding small amounts of Ti, but the same effect has not yet been observed in LiAlH 4 . To understand these mechanisms, detailed studies of the materials with and without the additive are necessary. In this study, two-dimensional slabs representing the open (0 1 0) and densely packed (1 0 1) surfaces of LiAlH 4 have been used to model adsorption of titanium atoms on those surfaces. The results show that the Ti atom tends to move below the surface towards interstitial sites rather than binding to a Li ion or AlH 4 complex at the surface

Hierarchical carambola-like Li4Ti5O12-TiO2 composites as advanced anode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Zhang, Yu; Zhang, Yun; Huang, Ling; Zhou, Zhongfu; Wang, Jingfeng; Liu, Heng; Wu, Hao

2016-01-01

Hierarchically structured Li 4 Ti 5 O 12 -TiO 2 (LTO-TiO 2 ) composites are synthesized using a facile hydrothermal approach upon reaction time control. With control over the time of hydrothermal reaction at 18 h, a hierarchical dual-phase LTO-TiO 2 composite with appropriate amount of anatase TiO 2 can be obtained, and it possesses a uniform carambola-like framework assembled by numerous ultrathin nanosheets, which enable a relatively large specific surface area, along with abundant interlayer channels to favor electrolyte penetration. When used as anode materials for lithium-ion batteries, such carambola-like LTO-TiO 2 composite exhibits remarkably improved capacity, high-rate capability, and cycling stability over other LTO-TiO 2 samples, which are synthesized at different time of hydrothermal reaction. Specifically, it deliveries a discharge capacity as high as 115.1 and 91.2 mAh g −1 at a very high current rate of 20 and 40C, respectively, while a stable reversible capacity of 171.7 mAh g −1 can be retained after 200 charge-discharge cycles at 1C, corresponding to 88.6% capacity retention. The excellent electrochemical performances benefit from the unique hierarchical carambola-like structure together with the mutually complementary intrinsic advantages between LTO and TiO 2 . The robust and porous nanosheets-assembled LTO-TiO 2 framework not only offers a shorter transport pathway for electron and Li-ion migration within this composite material, but also is able to alleviate the structure distortion during the fast Li-ion insertion/extraction process. The work described here shows that the hierarchical carambola-like LTO-TiO 2 composite is a promising anode material for high-power and long-life lithium-ion batteries.

High-rate nano-crystalline Li{sub 4}Ti{sub 5}O{sub 12} attached on carbon nano-fibers for hybrid supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Naoi, Katsuhiko; Isobe, Yusaku; Aoyagi, Shintaro [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8558 (Japan); Ishimoto, Shuichi [Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8558 (Japan); Nippon Chemi-Con Corporation, 363 Arakawa, Takahagi-shi, Ibaraki 318-8505 (Japan)

2010-09-15

A lithium titanate (Li{sub 4}Ti{sub 5}O{sub 12})-based electrode which can operate at unusually high current density (300 C) was developed as negative electrode for hybrid capacitors. The high-rate Li{sub 4}Ti{sub 5}O{sub 12} electrode has a unique nano-structure consisting of unusually small nano-crystalline Li{sub 4}Ti{sub 5}O{sub 12} (ca. 5-20 nm) grafted onto carbon nano-fiber anchors (nc-Li{sub 4}Ti{sub 5}O{sub 12}/CNF). This nano-structured nc-Li{sub 4}Ti{sub 5}O{sub 12}/CNF composite are prepared by simple sol-gel method under ultra-centrifugal force (65,000 N) followed by instantaneous annealing at 900 C for 3 min. A model hybrid capacitor cell consisting of a negative nc-Li{sub 4}Ti{sub 5}O{sub 12}/CNF composite electrode and a positive activated carbon electrode showed high energy density of 40 Wh L{sup -1} and high power density of 7.5 kW L{sup -1} comparable to conventional EDLCs. (author)

Versatile Coating of Lithium Conductive Li2TiF6 on Over-lithiated Layered Oxide in Lithium-Ion Batteries

International Nuclear Information System (INIS)

Choi, Wonchang; Benayard, Anass; Park, Jin-Hwan; Park, Junho; Doo, Seok-Gwang; Mun, Junyoung

2014-01-01

Highlights: • Li 2 TiF 6 coating was designed to grow surface lithium conductivity and stability. • We conducted an easy and versatile Li 2 TiF 6 lithium conductive coating on cathode. • The coating was performed very simply by ambient-temperature co-precipitation. • After the coating, rate capability, cycleability and thermal stability improved. - Abstract: We demonstrate an easy and versatile approach to modify a cathode-surface with a highly lithium–ion conductive layer by coating it with Li 2 TiF 6 . The thin and homogeneous Li 2 TiF 6 coating is introduced onto an over-lithiated layered oxide (OLO, namely Li 1.17 Ni 0.17 Co 0.1 Mn 0.56 O 2 ) surface via simple co-precipitation at ambient temperature by using Li 2 CO 3 and H 2 TiF 6 aqueous solutions. The lithium–conductive fluoride coating is expected to effectively suppress the undesired electrochemical and thermal interfacial reactions involving the OLO, which is critical in improving cycle performance and thermal stability. After Li 2 TiF 6 surface modification, the coated OLO materials showed high rate capability as well as long cyclability and improved thermal stability. The crystalline structure and surface microstructure of the prepared OLOs were investigated by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. Ultimately, the performances of the assembled lithium ion batteries were thoroughly investigated by electrochemical methods and thermal analysis

SnTe-TiC-C composites as high-performance anodes for Li-ion batteries

Science.gov (United States)

Son, Seung Yeon; Hur, Jaehyun; Kim, Kwang Ho; Son, Hyung Bin; Lee, Seung Geol; Kim, Il Tae

2017-10-01

Intermetallic SnTe composites dispersed in a conductive TiC/C hybrid matrix are synthesized by high-energy ball milling (HEBM). The electrochemical performances of the composites as potential anodes for Li-ion batteries are evaluated. The structural and morphological characteristics of the SnTe-TiC-C composites with various TiC contents are investigated by X-ray diffraction (XRD) and high-resolution transmission electron microscopy, which reveal that SnTe and TiC are uniformly dispersed in a carbon matrix. The electrochemical performance is significantly improved by introducing TiC to the SnTe-C composite; higher TiC contents result in better performances. Among the prepared composites, the SnTe-TiC (30%)-C and SnTe-TiC (40%)-C electrodes exhibit the best electrochemical performance, showing the reversible capacities of, respectively, 652 mAh cm-3 and 588 mAh cm-3 after 400 cycles and high rate capabilities with the capacity retentions of 75.4% for SnTe-TiC (30%)-C and 82.2% for SnTe-TiC (40%)-C at 10 A g-1. Furthermore, the Li storage reaction mechanisms of Te or Sn in the SnTe-TiC-C electrodes are confirmed by ex situ XRD.

Li{sub 2}ZrO{sub 3}-coated Li{sub 4}Ti{sub 5}O{sub 12} with nanoscale interface for high performance lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Zhang, Han [Jiangsu Lab of Advanced Functional Material, Changshu Institute of Technology, Changshu, 215500 (China); School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116 (China); Liu, Yang [School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116 (China); Wang, Ting; Yang, Yang [Jiangsu Lab of Advanced Functional Material, Changshu Institute of Technology, Changshu, 215500 (China); Shi, Shaojun [School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116 (China); Yang, Gang, E-mail: gyang@cslg.edu.cn [Jiangsu Lab of Advanced Functional Material, Changshu Institute of Technology, Changshu, 215500 (China); School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou 221116 (China)

2016-04-15

Graphical abstract: - Highlights: • Zr doped and Li{sub 2}ZrO{sub 3} coated Li{sub 4}Ti{sub 5}O{sub 12} are prepared by a solid-state method. • Zr-doping and LZO coating are positive in improving lithium diffusion ability. • Li{sub 2}ZrO{sub 3} coated Li{sub 4}Ti{sub 5}O{sub 12} deliver 168.1 mAh g{sup −1} higher than 150.2 mAh g{sup −1} of Li{sub 4}Ti{sub 5}O{sub 12}. • Li{sub 2}ZrO{sub 3} coated Li{sub 4}Ti{sub 5}O{sub 12} remains 162 mAh g{sup −1} after 100 cycles. • The lowest D{sub Li}{sup +} is 5.97 × 10{sup −17} and 1.85 × 10{sup −15} cm{sup 2} s{sup −1} of Li{sub 4}Ti{sub 5}O{sub 12} before and after coating. - Abstract: Zr doped sample of Li{sub 4}Ti{sub 4.99}Zr{sub 0.01}O{sub 12} (LZTO) and Li{sub 2}ZrO{sub 3} (LZO) coated Li{sub 4}Ti{sub 5}O{sub 12} (LTO) are prepared by a solid-state method. The lattice structure of LTO is remained after doping element of Zr and coating layer of LZO. The crystal structure and electrochemical performance of the material are investigated by X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT) and charge-discharge tests, respectively. Zr-doping and LZO coating play the positive role in improving the diffusion ability of lithium cations. LZTO and LZO-LTO show much improved specific capacity and rate capability compared with pristine sample of LTO. LZO-LTO has the smallest voltage differential (ΔV) of the redox peaks because the coating of Li{sub 2}ZrO{sub 3} is helpful for the diffusion ability of lithium ions during charge/discharge processes. LZTO and LZO-LTO as electrode deliver the initial capacities of 164.8, 168.1 mAh g{sup −1}, respectively, which are much higher than 150.2 mAh g{sup −1} of intrinsic sample of LTO. Even at the current density of 2 A g{sup −1}, LTZO and LZO-LTO offer capacity of 96 and 106 mAh g{sup −1}, which are much higher than 33 mAh g{sup −1} of LTO

Progress in the development of Li{sub 2}ZrO{sub 3} and Li{sub 2}TiO{sub 3} pebbles

Energy Technology Data Exchange (ETDEWEB)

Lulewicz, J D; Roux, N [CEA Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

1998-03-01

Li{sub 2}ZrO{sub 3} and Li{sub 2}TiO{sub 3} pebbles are being developed as ceramic breeder for the European Helium-cooled pebble bed DEMO blanket concept. Status is given of the fabrication work, and of the properties characteristics determination. (author)

Synthesis and electrochemical properties of Li4Ti5O12 spheres and its application for hybrid supercapacitors

International Nuclear Information System (INIS)

Deng, SiXu; Li, JingWen; Sun, ShiBing; Wang, Hao; Liu, JingBing; Yan, Hui

2014-01-01

Highlights: • Li 4 Ti 5 O 12 (LTO) spheres are prepared by molten-salt and TiO 2 spheres as template. • The LTO spheres are potential for using as anode for AC//LTO hybrid capacitor. • The AC//LTO hybrid supercapacitor presents good electrochemical performance. - Abstract: There is a growing demand for hybrid supercapacitor systems to combine the advantages of both lithium-ion battery and supercapacitors for the application of electric vehicles. We describe in this paper one kind of hybrid supercapacitor comprising spherical Li 4 Ti 5 O 12 as negative electrode and activated carbon (AC) as positive electrode in the non-aqueous electrolyte. The Li 4 Ti 5 O 12 spheres were synthesized using a LiCl-KCl molten-salt method and TiO 2 spheres as the template. The Li 4 Ti 5 O 12 spheres revealed high discharge capacity (168 mAh g −1 at 0.2 C), and a good capacity retention with high coulombic efficiency after cycling, which can be potential anode material for lithium ion batteries and negative material for hybrid supercapacitor. The AC//LTO hybrid supercapacitor exhibits excellent capacity retention of 93% after 500 cycles and offers higher energy density and power density than the AC//AC symmetric supercapacitor. The presented AC//LTO hybrid supercapacitor could be a competitive candidate for the promising energy storage devices

Enhanced Charge Extraction of Li-Doped TiO₂ for Efficient Thermal-Evaporated Sb₂S₃ Thin Film Solar Cells.

Science.gov (United States)

Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

2018-02-28

We provided a new method to improve the efficiency of Sb₂S₃ thin film solar cells. The TiO₂ electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb₂S₃ solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO₂ films. Compared with the undoped TiO₂, Li-doped mesoporous TiO₂ dramatically improved the photo-voltaic performance of the thermal-evaporated Sb₂S₃ thin film solar cells, with the average power conversion efficiency ( PCE ) increasing from 1.79% to 4.03%, as well as the improved open-voltage ( V oc ), short-circuit current ( J sc ) and fill factors. The best device based on Li-doped TiO₂ achieved a power conversion efficiency up to 4.42% as well as a V oc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb₂S₃ solar cells. This study showed that Li-doping on TiO₂ can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb₂S₃-based solar cells.

Effect of ball milling time on the hydrogen storage properties of TiF{sub 3}-doped LiAlH{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Liu, Shu-Sheng [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Li-Xian; Zhang, Yao; Zhang, Jian; Chu, Hai-Liang; Fan, Mei-Qiang; Zhang, Tao [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023 (China); Xu, Fen [Faculty of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Song, Xiao-Yan [College of Materials Science and Engineering, Key Laboratory of Advanced Functional Materials, Chinese Education Ministry, Beijing University of Technology, Beijing 100124 (China); Grolier, Jean Pierre [Laboratory of Thermodynamics of Solutions and Polymers, Blaise Pascal University, 24 Avenue des Landais, 63177-Aubiere Cedex (France)

2009-10-15

In the present work, the catalytic effect of TiF{sub 3} on the dehydrogenation properties of LiAlH{sub 4} has been investigated. Decomposition of LiAlH{sub 4} occurs during ball milling in the presence of 4 mol% TiF{sub 3}. Different ball milling times have been used, from 0.5 h to 18 h. With ball milling time increasing, the crystallite sizes of LiAlH{sub 4} get smaller (from 69 nm to 43 nm) and the dehydrogenation temperature becomes lower (from 80 C to 60 C). Half an hour ball milling makes the initial dehydrogenation temperature of doped LiAlH{sub 4} reduce to 80 C, which is 70 C lower than as-received LiAlH{sub 4}. About 5.0 wt.% H{sub 2} can be released from TiF{sub 3}-doped LiAlH{sub 4} after 18 h ball milling in the range of 60 C-145 C (heating rate 2 C min{sup -1}). TiF{sub 3} probably reacts with LiAlH{sub 4} to form the catalyst, TiAl{sub 3}. The mechanochemical and thermochemical reactions have been clarified. However, the rehydrogenation of LiAlH{sub 4}/Li{sub 3}AlH{sub 6} can not be realized under 95 bar H{sub 2} in the presence of TiF{sub 3} because of their thermodynamic properties. (author)

Nano-sized Li4Ti5O12 anode material with excellent performance prepared by solid state reaction: The effect of precursor size and morphology

International Nuclear Information System (INIS)

Li, Xiangru; Hu, Hao; Huang, Sheng; Yu, Gaige; Gao, Lin; Liu, Haowen; Yu, Ying

2013-01-01

Graphical abstract: - Highlights: • Nano-sized Li 4 Ti 5 O 12 has been prepared through solid state reaction by using axiolitic TiO 2 as precursor. • The prepared nano-sized Li 4 Ti 5 O 12 anode material shows excellent electrochemical performance. • The utilization of precursor with special morphology and size is one of the useful ways to prepare more active electrode materials. - Abstract: Spinel nano-sized Li 4 Ti 5 O 12 anode material of secondary lithium-ion battery has been successfully prepared by solid state reaction using axiolitic TiO 2 assembled by 10–20 nm nanoparticles and Li 2 CO 3 as precursors. The synthesis condition, grain size effect and corresponding electrochemical performance of the special Li 4 Ti 5 O 12 have been studied in comparison with those of the normal Li 4 Ti 5 O 12 originated from commercial TiO 2 . We also propose the mechanism that using the nano-scaled TiO 2 with special structure and unexcess Li 2 CO 3 as precursors can synthesize pure phase nano-sized Li 4 Ti 5 O 12 at 800 °C through solid state reaction. The prepared nano-sized Li 4 Ti 5 O 12 anode material for Li-ion batteries shows excellent capacity performance with rate capacity of 174.2, 164.0, 157.4, 146.4 and 129.6 mA h g −1 at 0.5, 1, 2, 5 and 10 C, respectively, and capacity retention of 95.1% after 100 cycles at 1 C. In addition, the specific capacity fade for the cell with the different Li 4 Ti 5 O 12 active materials resulted from the increase of internal resistance after 100 cycles is compared

Protoide šaknis *leh3u – "lietis, tekėti..." baltų kalbose (liet. liūtìs ir lietùs

Directory of Open Access Journals (Sweden)

Simas Karaliūnas

2011-10-01

Full Text Available THE PROTOIDE. ROOT *leh3u- “flow, stream, pour...” IN BALTIC (LITH. liūtìs “heavy shower, downpour” AND lietùs “rain” Summary The relationship of Lith. liū́tis/liūtìs “heavy shower, downpour” and lietùs “rain”, as has been suggested by P. Skardžius, may be understood only in the Protoindoeuropean prospect. Hit. lahui “it flows, streams, pours...”, Gr. λoύει “he bathes, washes” and Lat. lavit “id.” seem to have the apophonic o and their protoform should be reconstructed as *leh3-e/o, as proposed by F. Bader. Its root vocalism e is attested in Mycenaean Gr. re-wo-te-re-jo and Lith. liaũkti (-ia “flow, stream” <* leu(k-. Lith. liū́tis/liūtìs with suffix -ti- rests on the allomorph *lh3u- of this protoIE. root, attested, for instance, in Hit. li-lhuu̯ai- , le-lhuu̯ai- and possibly in Lat. perfect lāvī, if from *lh3u-ai. A verbal form * (apa-lh3u- [cf. Lat. ab-luō, Gr. άπο-λούω, Hit. appa(n lahhu-] might have served as a basis for derivatives Lith. pa-liū́tis, pa-liū́tė “long and heavy rain, a period of rains”. The palatalized l'< *li̯ of liū́tis, pa-liū́tis and pa-liū́tė attaches to the vocalism e form * leh3u ->* leu(k-> *liau(k-. With respect to their prefixal derivation the lake name Lith. At-lavas and Lat. ab-luvium, dī-luvium etc. “effusion, overflow, inundation, deluge” may be also compared and their root morpheme *-loui̯o- with the lake name Lith. Laujà identified. Due to structural analogy (:* leh3-u - there might have existed a parallel form * leh3-i- conserved in Lith. líeti (praes. líeja, lẽja, praet. líejo, lė́jo ”pour“ and Latv. liêt (praes. leju, praet. lêju “id.”, from which Lith. lietús “rain”, Latv. liêtus “id.” are derived with suffix -tu-.

Zr4+ doping in Li4Ti5O12 anode for lithium-ion batteries: open Li+ diffusion paths through structural imperfection.

Science.gov (United States)

Kim, Jae-Geun; Park, Min-Sik; Hwang, Soo Min; Heo, Yoon-Uk; Liao, Ting; Sun, Ziqi; Park, Jong Hwan; Kim, Ki Jae; Jeong, Goojin; Kim, Young-Jun; Kim, Jung Ho; Dou, Shi Xue

2014-05-01

One-dimensional nanomaterials have short Li(+) diffusion paths and promising structural stability, which results in a long cycle life during Li(+) insertion and extraction processes in lithium rechargeable batteries. In this study, we fabricated one-dimensional spinel Li4Ti5O12 (LTO) nanofibers using an electrospinning technique and studied the Zr(4+) doping effect on the lattice, electronic structure, and resultant electrochemical properties of Li-ion batteries (LIBs). Accommodating a small fraction of Zr(4+) ions in the Ti(4+) sites of the LTO structure gave rise to enhanced LIB performance, which was due to structural distortion through an increase in the average lattice constant and thereby enlarged Li(+) diffusion paths rather than changes to the electronic structure. Insulating ZrO2 nanoparticles present between the LTO grains due to the low Zr(4+) solubility had a negative effect on the Li(+) extraction capacity, however. These results could provide key design elements for LTO anodes based on atomic level insights that can pave the way to an optimal protocol to achieve particular functionalities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solvothermal coating LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2} microspheres with nanoscale Li{sub 2}TiO{sub 3} shell for long lifespan Li-ion battery cathode materials

Energy Technology Data Exchange (ETDEWEB)

Wu, Naiteng; Wu, Hao; Liu, Heng; Zhang, Yun, E-mail: y_zhang@scu.edu.cn

2016-04-25

LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2} (NCA) microspheres covered by a nanoscale Li{sub 2}TiO{sub 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{sub 2}TiO{sub 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{sub 2}TiO{sub 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{sub 2}TiO{sub 3}-coated LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 2} microsphere is a promising cathode material for Li-ion batteries with long lifespan. - Graphical abstract: Nanoscale Li{sub 2}TiO{sub 3}-based shell encapsulated LiNi{sub 0.8}Co{sub 0.15}Al{sub 0.05}O{sub 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{sub 2}TiO{sub 3} is used as coating

Spherical Li{sub 4}Ti{sub 5}O{sub 12} synthesized by spray drying from a different kind of solution

Energy Technology Data Exchange (ETDEWEB)

He Zhenjiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Wang Zhixing, E-mail: zhixingwang163@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Wu Feixiang; Guo Huajun; Li Xinhai; Xiong Xunhui [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

2012-11-05

Highlights: Black-Right-Pointing-Pointer The precursor powders comprise hollow particles. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} acts as coordination agent that reacts with the Ti to form a large anion. Black-Right-Pointing-Pointer Li{sub 4}Ti{sub 5}O{sub 12} powders can be synthesized at a low temperature of 700 Degree-Sign C. Black-Right-Pointing-Pointer The spherical Li{sub 4}Ti{sub 5}O{sub 12} powders show excellent electrochemical performance. Black-Right-Pointing-Pointer We hope our work will be helpful for other research groups. - Abstract: High energy density Li{sub 4}Ti{sub 5}O{sub 12} powders comprising of spherical nanocrystalline are synthesized by spray drying followed by solid-state calcination. The influences of Li/Ti atomic ratios (0.784, 0.800, 0.816, and 0.832) on the performance of Li{sub 4}Ti{sub 5}O{sub 12} are investigated by means of Thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscope (TEM), Galvanostatic cell cycling, as well as Ac impedance spectroscopy. The results indicate that, when the spray-drying precursors at the Li/Ti molar ratio of 0.816 are calcined at 700 Degree-Sign C for 16 h in air, a pure LTO phase with a lithium-excess composition is obtained, which shows the best properties. Between 1.0 and 2.5 V (vs. Li/Li{sup +}), the initial discharge capacities of the powder are 174, 168, 163, 153, and 136 mAhg{sup -1} at a constant current density of 0.1, 0.5, 1, 2, and 5 C, respectively. After 100 cycles, the discharge capacities of the LTO powders remain 97, 95, and 99% of initial discharge capacities at current densities of 1, 2, and 5 C, respectively.

Characterization of Al-Ti phases in cycled TiF3-enhanced Na2LiAlH6

International Nuclear Information System (INIS)

Nakamura, Y.; Fossdal, A.; Brinks, H.W.; Hauback, B.C.

2006-01-01

TiF 3 -enhanced Na 2 LiAlH 6 was investigated after dehydrogenation-hydrogenation cycles by synchrotron X-ray diffraction. There was no sign of Ti after ball-milling with TiF 3 , but two types of Al-Ti phases were observed in the cycled samples. In a sample after measuring five pressure-composition isotherms in the temperature range from 170 to 250 deg. C, a fcc phase with a = 3.987 A was observed. This phase is considered to be Al 3 Ti with the L1 2 structure. Samples after one or four cycles at selected temperatures between 170 and 250 deg. C showed diffraction from another fcc phase with a ∼ 4.03 A. This indicates formation of an Al 1-y Ti y solid-solution phase with y ∼ 0.15 similar to previously reported for cycled NaAlH 4 with Ti additives

Nanostructured Si/TiC composite anode for Li-ion batteries

International Nuclear Information System (INIS)

Zeng, Z.Y.; Tu, J.P.; Yang, Y.Z.; Xiang, J.Y.; Huang, X.H.; Mao, F.; Ma, M.

2008-01-01

Si/TiC nanocomposite anode was synthesized by a surface sol-gel method in combination with a following heat-treatment process. Through this process, nanosized Si was homogeneously distributed in a titanium carbide matrix. The electrochemically less active TiC working as a buffer matrix successfully prevented Si from cracking/crumbling during the charging/discharging process. The interspaces in the Si/TiC nanocomposite could offer convenient channels for Li ions to react with active Si. The Si/TiC composite exhibited a reversible charge/discharge capacity of about 1000 mAh g -1 with average discharge capacity fading of 1.8 mAh g -1 (0.18%) from 2nd to 100th cycle, indicating its excellent cyclability when used as anode materials for lithium-ion batteries

Monoclinic β-Li{sub 2}TiO{sub 3} nanocrystalline particles employing novel urea assisted solid state route: Synthesis, characterization and sintering behavior

Energy Technology Data Exchange (ETDEWEB)

Tripathi, Biranchi M., E-mail: biranchi.barc@gmail.com [Powder Metallurgy Division, Bhabha Atomic Research Centre, Vashi Complex, Navi Mumbai 400705 (India); Mohanty, Trupti; Prakash, Deep [Powder Metallurgy Division, Bhabha Atomic Research Centre, Vashi Complex, Navi Mumbai 400705 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Sinha, P.K. [Powder Metallurgy Division, Bhabha Atomic Research Centre, Vashi Complex, Navi Mumbai 400705 (India)

2017-07-15

Pure phase monoclinic nano-crystalline Li{sub 2}TiO{sub 3} powder was synthesized by a novel urea assisted solid state synthesis method using readily available and economical precursors. A single phase and well crystalline Li{sub 2}TiO{sub 3} powder has been obtained at slightly lower temperature (600–700 °C) and shorter duration (2 h) as compared to the conventional solid state method. The proposed method has significant advantages in comparison to other viable methods mainly in terms of phase purity, powder properties and sinterability. Analysis of chemical composition using inductively coupled plasma atomic emission spectroscopy (ICP-AES) shows no loss of lithium from Li{sub 2}TiO{sub 3} in the proposed method. The emergence of monoclinic Li{sub 2}TiO{sub 3} phase was confirmed by X-ray diffraction (XRD) pattern of as-synthesized powder. The crystallite size of Li{sub 2}TiO{sub 3} powder was calculated to be in the range of 15–80 nm, which varied as a function of urea composition and temperature. The morphology of as-prepared Li{sub 2}TiO{sub 3} powders was examined by scanning electron microscope (SEM). The effect of urea composition on phase and morphology was investigated so as to delineate the role of urea. Upon sintering at < 1000 °C temperature, the Li{sub 2}TiO{sub 3} powder compact attained about 98% of the theoretical density with fine grained (grain size: 2–3 μm) microstructure. It indicates excellent sinter-ability of Li{sub 2}TiO{sub 3} powder synthesized by the proposed method. The fine grained structure is desirable for better tritium breeding performance of Li{sub 2}TiO{sub 3}. Electrochemical impedance spectroscopy at variable temperature showed good electrical properties of Li{sub 2}TiO{sub 3}. The proposed method is simple, anticipated to be cost effective and convenient to realise for large scale production of phase pure nanocrystalline and having significantly enhanced sinter-ability Li{sub 2}TiO{sub 3} powder.

Microstructures and mechanical properties of grain refined Al-Li-Mg casting alloy by containing Zr and Ti

International Nuclear Information System (INIS)

Saikawa, Seiji; Nakai, Kiyoshi; Sugiura, Yasuo; Kamio, Akihiko.

1995-01-01

Mechanical properties and microstructures of various Al-Li-Mg alloy castings containing small amount of Zr and/or Ti were investigated. The δ(AlLi) phase was observed to crystallize in the dendrite-cell gaps as well as on the grain boundaries. Microsegregation of Mg also occurred in the solidified castings. The β(Al 3 Zr) or Al-Zr-Ti compounds crystallize during solidification and remain even after solid solution treatment at 803 K for 36 ks. The grain sizes of Al-2.5%Li-2%Mg alloy castings become finer by the addition of 0.15%Zr and 0.12%Ti compared with each addition of 0.15%Zr or 0.12%Ti. The age hardening is accelerated by the addition of 0.15%Zr. In an Al-2.5%Li-2%Mg-0.15%Zr-0.12%Ti alloy casting poured into a metallic mold and aged at 453 K for 36 ks, ultimate tensile strength, Young's modulus and density were 417 MPa, 80 GPa and was 2.52 g/cm 3 , respectively. Its specific strength and modulus are higher by 50.3 and 13.9% than those of the conventional AC4C-T6 casting. (author)

Li4 Ti5 O12 Anode: Structural Design from Material to Electrode and the Construction of Energy Storage Devices.

Science.gov (United States)

Chen, Zhijie; Li, Honsen; Wu, Langyuan; Lu, Xiaoxia; Zhang, Xiaogang

2018-03-01

Spinel Li 4 Ti 5 O 12 , known as a zero-strain material, is capable to be a competent anode material for promising applications in state-of-art electrochemical energy storage devices (EESDs). Compared with commercial graphite, spinel Li 4 Ti 5 O 12 offers a high operating potential of ∼1.55 V vs Li/Li + , negligible volume expansion during Li + intercalation process and excellent thermal stability, leading to high safety and favorable cyclability. Despite the merits of Li 4 Ti 5 O 12 been presented, there still remains the issue of Li 4 Ti 5 O 12 suffering from poor electronic conductivity, manifesting disadvantageous rate performance. Typically, a material modification process of Li 4 Ti 5 O 12 will be proposed to overcome such an issue. However, the previous reports have made few investigations and achievements to analyze the subsequent processes after a material modification process. In this review, we attempt to put considerable interest in complete device design and assembly process with its material structure design (or modification process), electrode structure design and device construction design. Moreover, we have systematically concluded a series of representative design schemes, which can be divided into three major categories involving: (1) nanostructures design, conductive material coating process and doping process on material level; (2) self-supporting or flexible electrode structure design on electrode level; (3) rational assembling of lithium ion full cell or lithium ion capacitor on device level. We believe that these rational designs can give an advanced performance for Li 4 Ti 5 O 12 -based energy storage device and deliver a deep inspiration. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interference of intrinsic UV response of LiF:Mg,Ti (Poland) pellets in dose reassessment

International Nuclear Information System (INIS)

Bhasin, B.D.; Kalyane, G.N.; Kathuria, S.P.; Sunta, C.M.

1987-01-01

The thermoluminescence (TL) behaviour of sintered pellets of LiF:Mg,Ti (Poland) (LiF(P)) is markedly different from that of LiF:Mg,Ti TLD-100 (Harshaw) phosphor as far as their intrinsic responses to ultraviolet (UV) (253.7 nm) radiation are concerned. The intrinsic response of LiF(P) phosphor is very much dependent on the physical form of the phosphor. In addition, it is highly sensitive to any changes in experimental conditions such as the nature of the atmosphere during readout, the pre-heat and the readout history of the phosphor. The high intrinsic UV response (IUVR) of LiF(P) interferes in the dose reassessment by the PTTL (photo-transferred thermoluminescence) technique. Nevertheless, a fortuitous situation exists wherein a PTTL dosimetry peak signal is seen clearly over-riding the IUVR valley at the corresponding point of the glow curve. A procedure to correct for the IUVR interference and to re-estimate the dose by the PTTL technique is described. (author)

Amorphous and crystalline TiO2 nanotube arrays for enhanced Li-ion intercalation properties.

Science.gov (United States)

Guan, Dongsheng; Cai, Chuan; Wang, Ying

2011-04-01

We have employed a simple process of anodizing Ti foils to prepare TiO2 nanotube arrays which show enhanced electrochemical properties for applications as Li-ion battery electrode materials. The lengths and pore diameters of TiO2 nanotubes can be finely tuned by varying voltage, electrolyte composition, or anodization time. The as-prepared nanotubes are amorphous and can be converted into anatase nanotubes with heat treatment at 480 degrees C. Rutile crystallites emerge in the anatase nanotube when the annealing temperature is increased to 580 degrees C, resulting in TiO2 nanotubes of mixed phases. The morphological features of nanotubes remain unchanged after annealing. Li-ion insertion performance has been studied for amorphous and crystalline TiO2 nanotube arrays. Amorphous nanotubes with a length of 3.0 microm and an outer diameter of 125 nm deliver a capacity of 91.2 microA h cm(-2) at a current density of 400 microA cm(-2), while those with a length of 25 microm and an outer diameter of 158 nm display a capacity of 533 microA h cm-2. When the 3-microm long nanotubes become crystalline, they deliver lower capacities: the anatase nanotubes and nanotubes of mixed phases show capacities of 53.8 microA h cm-2 and 63.1 microA h cm(-2), respectively at the same current density. The amorphous nanotubes show excellent capacity retention ability over 50 cycles. The cycled nanotubes show little change in morphology compared to the nanotubes before electrochemical cycling. All the TiO2 nanotubes demonstrate higher capacities than amorphous TiO2 compact layer reported in literature. The amorphous TiO2 nanotubes with a length of 1.9 microm exhibit a capacity five times higher than that of TiO2 compact layer even when the nanotube array is cycled at a current density 80 times higher than that for the compact layer. These results suggest that anodic TiO2 nanotube arrays are promising electrode materials for rechargeable Li-ion batteries.

lin-4 and the NRDE pathway are required to activate a transgenic lin-4 reporter but not the endogenous lin-4 locus in C. elegans.

Science.gov (United States)

Jiao, Alan L; Foster, Daniel J; Dixon, Julia; Slack, Frank J

2018-01-01

As the founding member of the microRNA (miRNA) gene family, insights into lin-4 regulation and function have laid a conceptual foundation for countless miRNA-related studies that followed. We previously showed that a transcriptional lin-4 reporter in C. elegans was positively regulated by a lin-4-complementary element (LCE), and by lin-4 itself. In this study, we sought to (1) identify additional factors required for lin-4 reporter expression, and (2) validate the endogenous relevance of a potential positive autoregulatory mechanism of lin-4 expression. We report that all four core nuclear RNAi factors (nrde-1, nrde-2, nrde-3 and nrde-4), positively regulate lin-4 reporter expression. In contrast, endogenous lin-4 levels were largely unaffected in nrde-2;nrde-3 mutants. Further, an endogenous LCE deletion generated by CRISPR-Cas9 revealed that the LCE was also not necessary for the activity of the endogenous lin-4 promoter. Finally, mutations in mature lin-4 did not reduce primary lin-4 transcript levels. Taken together, these data indicate that under growth conditions that reveal effects at the transgenic locus, a direct, positive autoregulatory mechanism of lin-4 expression does not occur in the context of the endogenous lin-4 locus.

lin-4 and the NRDE pathway are required to activate a transgenic lin-4 reporter but not the endogenous lin-4 locus in C. elegans.

Directory of Open Access Journals (Sweden)

Alan L Jiao

Full Text Available As the founding member of the microRNA (miRNA gene family, insights into lin-4 regulation and function have laid a conceptual foundation for countless miRNA-related studies that followed. We previously showed that a transcriptional lin-4 reporter in C. elegans was positively regulated by a lin-4-complementary element (LCE, and by lin-4 itself. In this study, we sought to (1 identify additional factors required for lin-4 reporter expression, and (2 validate the endogenous relevance of a potential positive autoregulatory mechanism of lin-4 expression. We report that all four core nuclear RNAi factors (nrde-1, nrde-2, nrde-3 and nrde-4, positively regulate lin-4 reporter expression. In contrast, endogenous lin-4 levels were largely unaffected in nrde-2;nrde-3 mutants. Further, an endogenous LCE deletion generated by CRISPR-Cas9 revealed that the LCE was also not necessary for the activity of the endogenous lin-4 promoter. Finally, mutations in mature lin-4 did not reduce primary lin-4 transcript levels. Taken together, these data indicate that under growth conditions that reveal effects at the transgenic locus, a direct, positive autoregulatory mechanism of lin-4 expression does not occur in the context of the endogenous lin-4 locus.

Gas swelling behaviour at different stages in Li4Ti5O12/LiNi1/3Co1/3Mn1/3O2 pouch cells

Science.gov (United States)

Liu, Wei; Liu, Haohan; Wang, Qian; Zhang, Jian; Xia, Baojia; Min, Guoquan

2017-11-01

Gas swelling behaviour is a major drawback of batteries that are based on Li4Ti5O12 anode materials and hinders their application. In this article, the morphology and electronic structure changes of Li4Ti5O12 electrodes at ageing and cycling stages are investigated using scanning electron microscopy, X-ray absorption near-edge structure and X-ray photoelectron spectroscopy. A simple method that uses an air bag to collect the generated gases was conducted and the gases were then characterised by gas chromatography/mass spectrometry. The results indicate that the charge transformation of Ti ions would aggravate the gas swelling behaviour. The solid electrolyte interphase (SEI) films form on the surface of the Li4Ti5O12 particles and become thicker with increasing charge state. The gas components change significantly during the ageing and cycling, indicating the complexity of the gas swelling mechanism.

The sup 8 Li(n,. gamma. ) sup 9 Li reaction and primordial nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Mao, Z Q; Champagne, A E [Princeton Univ., NJ (USA). Dept. of Physics

1991-01-01

Shell-model calculations, using both p-shell and spd-shell interactions, have been used to predict the spectroscopic properties of low-lying states in {sup 9}Li. From this information, we have obtained new estimates for the rate of the {sup 8}Li(n,{gamma}){sup 9}Li reaction, which may act to limit the production of heavy elements during an inhomogeneous big bang. The two calculations produce reaction rates which differ by about a factor of 2 at the temperatures of interest, demonstrating the uncertainties in this approach. However, the spd calculation appears to be the more reliable of the two. (orig.).

Chlorine Doping of Amorphous TiO2 for Increased Capacity and Faster Li+-Ion Storage

NARCIS (Netherlands)

Moitzheim, S.; Balder, J.E.; Poodt, P.; Unnikrishnan, S.; Gendt, S. de; Vereecken, P.M.

2017-01-01

Titania (TiO2) offers a high theoretical capacity of 336 mAh g-1 with the insertion of one Li per Ti unit. Unfortunately, the poor ionic and electronic conductivity of bulk TiO2 electrodes limits its practical implementation. Nanosizing titania below ∼20 nm has shown to increase the rate performance

An infrared study of the surface chemistry of lithium titanate spinel (Li4Ti5O12)

International Nuclear Information System (INIS)

Snyder, Mark Q.; DeSisto, William J.; Tripp, Carl P.

2007-01-01

While there are numerous studies examining the performance of lithium titanate spinel (LTS) as a lithium-ion battery, little is known about the surface chemistry of this material. In this paper, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy spectroscopy was used to study the type of surface groups present on LTS as a function of temperature. The surface was found to contain isolated and hydrogen-bonded TiOH groups and the dehydroxylation behavior with thermal treatment was similar to that of TiO 2 . In addition, hexamethyldisilazane (HMDZ) and pyridine were used to probe the reactivity of surface hydroxyl groups and the presence of Lewis acid sites, respectively. The reaction of HMDZ occurred with both LiOH and TiOH groups to form Li-O-Si and Ti-O-Si. In addition, the reaction of gaseous CO 2 with the Li + ions resulted in the formation of surface carbonate ions. The carbonate ions are removed by heating at 400 deg. C in air

Synthesis and enhanced electrochemical performance of the honeycomb TiO2/LiMn2O4 cathode materials

DEFF Research Database (Denmark)

Zhang, J.Y.; Shen, J.X.; Wei, C.B.

2016-01-01

angle compare to LiMn2O4, implying that TiO2 doping induced a change of crystal structure. By performing electrochemical measurements, we observed an enhancement of specific capacity (127.28 mAhg−1) and an improvement of cycling stability in the TiO2/LiMn2O4 hybrid materials. After 100 cycles of charge...

Effect of rigidity of porous structure on electrochemical behavior of pristine Li4Ti5O12 microspheres

International Nuclear Information System (INIS)

Jia, Zhenyong; Zhou, Qun; Li, Xiaowei; Fu, Yu; Ming, Hai; Zheng, Junwei

2015-01-01

Highlights: • Rigid porous framework of Li 4 Ti 5 O 12 microspheres can be fabricated by mutual molten growth of primary particles. • Well-confined nanosized tortuous channels are formed inside Li 4 Ti 5 O 12 microspheres. • Li 4 Ti 5 O 12 microspheres with rigid porous structures exhibit greatly enhanced electrochemical performance. - Abstract: Highly controllable porous architecture is desirable to tailor the physical and chemical properties of functional materials in advanced lithium ion batteries. Here, porous microspheres of spinel lithium titanate (Li 4 Ti 5 O 12 ), a promising alternative anode material for lithium ion batteries, are fabricated by mutual molten growth method in a controllable manner. The key role of the rigidity of the porous structure on the performance of the electrode materials in lithium ion batteries is demonstrated. Rigid framework of the materials is formed by second growth of the primary particles that fused together to generate an interconnected nanopore system inside the spheres, leading to better electrolyte diffusion and lower interparticle contact resistance, relative to the non-porous counterpart. The pristine Li 4 Ti 5 O 12 microspheres with uniform pore distribution and continuous framework exhibit high tap density, remarkable reversible capacity and rate capability, as well as excellent cycling stability. The present method is scalable and may provide a new approach to fabricate other candidate electrode materials for applications that require both high power and high volumetric energy density

Fabrication of Li2TiO3 pebbles by a freeze drying process

International Nuclear Information System (INIS)

Lee, Sang-Jin; Park, Yi-Hyun; Yu, Min-Woo

2013-01-01

Li 2 TiO 3 pebbles were successfully fabricated by using a freeze drying process. The Li 2 TiO 3 slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li 2 TiO 3 pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined

Complex titanates Sr_1_-_xPb_xLi_2Ti_6O_1_4 (0≤x≤1) as anode materials for high-performance lithium-ion batteries

International Nuclear Information System (INIS)

Qian, Shangshu; Yu, Haoxiang; Yan, Lei; Li, Peng; Lin, Xiaoting; Wu, Yaoyao; Long, Nengbing; Shui, Miao; Shu, Jie

2016-01-01

Highlights: • Sr_1_-_xPb_xLi_2Ti_6O_1_4 (0≤x≤1) is prepared by a simple solid state reaction. • Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 exhibits enhanced lithium storage capability. • Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 can deliver a capacity of 141.8 mAh g"−"1 at 700 mA g"−"1. • In-situ XRD is performed to study the reversibility of Sr_1_-_xPb_xLi_2Ti_6O_1_4. - Abstract: With the Pb doping content at Sr-site increasing, a series of Sr_1_-_xPb_xLi_2Ti_6O_1_4 (x = 0, 0.25, 0.50, 0.75, 1.0) are synthesized by a simple solid-state reaction. It is found that the reversible capacity and rate capability experience a parabolic course from SrLi_2Ti_6O_1_4 to PbLi_2Ti_6O_1_4. Among all the as-prepared samples, Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 shows the best cycling and rate properties. It delivers an initial charge capacity of 163.2 mAh g"−"1 at 100 mA g"−"1 with the capacity retention of 96.08% after 100 cycles. In addition, it can also deliver a reversible capacity of 141.8 mAh g"−"1 at 700 mA g"−"1. The superior electrochemical properties of Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 are attributed to the reduced charge transfer resistance and increased lithium-ion diffusion coefficient after doping. Besides, in-situ X-ray diffraction is also performed to investigate the lithium-ion insertion/extraction behaviors of SrLi_2Ti_6O_1_4, Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 and PbLi_2Ti_6O_1_4. The observed results confirm that Sr_0_._5Pb_0_._5Li_2Ti_6O_1_4 has good structural stability and reversibility for repeated lithium storage.

In vitro expansion of Lin+ and Lin- mononuclear cells from human peripheral blood

Science.gov (United States)

Norhaiza, H. Siti; Rohaya, M. A. W.; Zarina, Z. A. Intan; Hisham, Z. A. Shahrul

2013-11-01

Haematopoietic stem cells (HSCs) are used in the therapy of blood disorders due to the ability of these cells to reconstitute haematopoietic lineage cells when transplanted into myeloablative recipients. However, substantial number of cells is required in order for the reconstitution to take place. Since HSCs present in low frequency, larger number of donor is required to accommodate the demand of transplantable HSCs. Therefore, in vitro expansion of HSCs will have profound impact on clinical purposes. The aim of this study was to expand lineage negative (Lin-) stem cells from human peripheral blood. Total peripheral blood mononuclear cells (PBMNCs) were fractionated from human blood by density gradient centrifugation. Subsequently, PBMNCs were subjected to magnetic assisted cell sorter (MACS) which depletes lineage positive (Lin+) mononuclear cells expressing lineage positive markers such as CD2, CD3, CD11b, CD14, CD15, CD16, CD19, CD56, CD123, and CD235a to obtained Lin- cell population. The ability of Lin+ and Lin- to survive in vitro was explored by culturing both cell populations in complete medium consisting of Alpha-Minimal Essential Medium (AMEM) +10% (v/v) Newborn Calf Serum (NBCS)+ 2% (v/v) pen/strep. In another experiment, Lin+ and Lin- were cultured with complete medium supplemented with 10ng/mL of the following growth factors: stem cell factor (SCF), interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF), 2IU/mL of Erythropoietin (Epo) and 20ng/mL of IL-6. Three samples were monitored in static culture for 22 days. The expansion potential was assessed by the number of total viable cells, counted by trypan blue exclusion assay. It was found that Lin+ mononuclear cells were not able to survive either in normal proliferation medium or proliferation medium supplemented with cytokines. Similarly, Lin- stem cells were not able to survive in proliferation medium however, addition of cytokines into the proliferation medium support Lin

Additives affecting properties of β-Li{sub 2}TiO{sub 3} pebbles in a modified indirect wet chemistry process

Energy Technology Data Exchange (ETDEWEB)

Yu, Cheng-Long, E-mail: johnyucl@aliyun.com [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Research Laboratory of Hydrothermal Chemistry, Faculty of Science, The Kochi University, Kochi 780-8520 (Japan); Liu, Wei; Yang, Long-Tao; Wang, Dao-Yi; Wu, Kang [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Zhang, Zeng-Ping [Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang' an University, Xi' an 710064 (China); Wang, Xiu-Feng [School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Yanagisawa, Kazumichi [Research Laboratory of Hydrothermal Chemistry, Faculty of Science, The Kochi University, Kochi 780-8520 (Japan)

2016-11-15

Lithium metatitanate (β-Li{sub 2}TiO{sub 3}) pebbles were fabricated via the modified indirect wet chemistry method. Effect of varied additives, as polyvinyl alcohol, glycerol, and agar on the properties evolution was investigated. The highest density is obtained by adding 2 wt% (weight percent) polyvinyl alcohol, 3 wt% glycerol, and 3 wt% agar, respectively. β-Li{sub 2}TiO{sub 3} pebbles with relative sintered density of 92.4%T.D. (Theoretical Density), the ratio of the intensity of diffraction peak (002) to that of (−133) of about 2.93, about 1.58 mm in diameter, a better sphericity of 1.02, the particle size of 5–6 μm, and the well-developed surface layered structure are successfully fabricated with 3 wt% glycerol. Glycerol is beneficial to improving the properties by other fabrication method as well. - Highlights: • Polyvinyl alcohol, glycerol, and agar were used to prepare β-Li{sub 2}TiO{sub 3} pebbles. • Properties of the β-Li{sub 2}TiO{sub 3} pebbles were governed by the additives. • Glycerol is beneficial to improving the properties of β-Li{sub 2}TiO{sub 3} pebbles.

Crystal structures of LiCsTiF6 and Cs2TiF6 and interval mobility of complex anions

International Nuclear Information System (INIS)

Popov, D.Yu.; Kavun, V.Ya.; Gerasimenko, A.V.; Sergienko, V.I.; Antokhina, T.F.

2002-01-01

The structure of LiCsTiF 6 (1) and Cs 2 TiF 6 (2) monocrystals was studied by the method of X-ray diffraction analysis. Crystal lattice parameters for compound 1 are: a = 9.251 (1), b = 11.920 (1), c = 10.271 (1), sp.gr. Pbcn, Z = 8; for compound 2: a = 6.213 (1), c = 5.004 (1), sp.gr. P3-bar m1, Z = 1. Three-dimensional frame of bound titanium octahedrons and slightly distorted lithium tetragonal pyramids with Li-F distance ranging from 1.86 to 2.24 A is the crystal structure base of compound 1. The structure of compound 2 is made of dose-packed CsF 3 layers and TiF 6 2- octahedrons located between the layers. The types of internal motion of the complex anions were determined by 10 F NMR method, their activation energy in crystals 1 and 2 in the temperature range of 200-500 K being estimated [ru

Long-term changes in the radiation-induced optical absorption bands of LiF:Mg,Ti

International Nuclear Information System (INIS)

Kelemen, A.

1996-01-01

Optical absorption spectroscopy plays an exceptional role in the identification of charge traps responsible for the different TL peaks of the TL phosphors. Experiments carried out under different conditions, e.g. with different types of ionising radiation and/or different dose rates, applying different annealing procedures and/or different storage times after the irradiation, may lead to contradictory results. Therefore, a systematic investigation was conducted of the build-up and decay characteristics of the optical absorption bands of different LiF:Mg,Ti single crystal samples. Important changes were found in the long (hours and days) time scale. For example, the 350 nm optical absorption increases continuously in the Mg free LiF:Ti sample, while the intensities of the 310 nm and 380 nm absorption bands decrease in the sample containing Mg even several hours after irradiation with ∼ 5 μs, 4 MeV linear accelerator electron pulses. These experimental results may have serious consequences for the interpretation of optical absorption data and for the understanding of defect and energy storage mechanisms of thermoluminescence in LiF:Mg,Ti. (author)

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%.

Evaluation of tritium release behavior from Li{sub 2}TiO{sub 3} during DT neutron irradiation by use of an improved tritium collection method

Energy Technology Data Exchange (ETDEWEB)

Edao, Yuki, E-mail: edao.yuki@jaea.go.jp [Tritium Technology Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kawamura, Yoshinori [Blanket Technology Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Omotedate Obuchi, Rokkasho, Aomori 039-3212 (Japan); Ochiai, Kentaro [BA Project Coordination Group, Department of Fusion Power Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Omotedate Obuchi, Rokkasho, Aomori 039-3212 (Japan)

2016-11-15

Highlights: • Behavior of tritium released from Li{sub 2}TiO{sub 3} under neutron irradiation was measured. • Tritium collection method with hydrophobic catalyst was demonstrated successfully. • Temperature of Li{sub 2}TiO{sub 3} was dominant to control the chemical form of tritium release. - Abstract: The accurate measurement of behavior of bred tritium released from a tritium breeder is indispensable to understand the behavior for a design of a tritium extraction system. The tritium collection method combined a CuO bed and water bubbles was not suitable to measure transient behavior of tritium released from Li{sub 2}TiO{sub 3} during neutron irradiation because tritium released behavior was changed to be delayed due to adsorption of oxidized tritium on the CuO. Hence, the tritium collection method with hydrophobic catalyst instead of the CuO was demonstrated and succeeded the accurate release measurement of tritium from Li{sub 2}TiO{sub 3}. With the method, we assessed the behavior of tritium release under the various conditions since tritium should be released from Li{sub 2}TiO{sub 3} as the form of HT as much as possible from the view point of the fuel cycle. Our results indicated; promotion of isotopic exchange reaction on the surface of Li{sub 2}TiO{sub 3} by addition of hydrogen in sweep gas is mandatory in order to release tritium smoothly from Li{sub 2}TiO{sub 3} irradiated with neutrons; the favorable sweep gas to release as the form of HT was hydrogen added inert gas; and the temperature of Li{sub 2}TiO{sub 3} was the dominant parameter to control the chemical form of tritium released from the Li{sub 2}TiO{sub 3}.

Ion-exchange synthesis and improved Li insertion property of lithiated H2Ti12O25 as a negative electrode material for lithium-ion batteries

Directory of Open Access Journals (Sweden)

Kunimitsu Kataoka

2016-03-01

Full Text Available We successfully prepared the lithiated H2Ti12O25 sample by the H+/Li+ ion exchange synthetic technique in the molten LiNO3 at 270 °C using H2Ti12O25 as a starting compound. Chemical composition of the obtained lithiated H2Ti12O25 sample was determined to be H1.05Li0.35Ti12O25-δ having δ = 0.3 by ICP-AES and DTA-TG analyses. The H+/Li+ ion exchange was also confirmed by powder XRD, 1H-MAS NMR, and 7Li-MAS NMR measurements. Electrochemical Li insertion and extraction measurements revealed that the initial coulombic efficiency was improved from 88% in H2Ti12O25 to 93% in the lithiated H2Ti12O25 sample. In addition, superior capacity retention properties for the charge and discharge cycling performance and good charge rate capability of the present lithiated H2Ti12O25 were confirmed in the electrochemical measurements. Accordingly, the lithiated H2Ti12O25 is suggested to be one of the promising high-voltage and high-capacity oxide negative electrodes in advanced lithium-ion batteries.

A study into the mechanism of thermoluminescence in a LiF:Mg,Ti dosimetry material

Energy Technology Data Exchange (ETDEWEB)

Piters, T M

1993-10-11

Thermoluminescence (TL) is the phenomenon of light emission from an insulator or semiconductor when it is heated after a previous absorption of energy from ionising radiation. The purpose of the research described in this thesis is to get more insight into the mechanism of TL in LiF:Mg, Ti. In chapter 2 the idea of defect reactions during the readout is introduced as a possible explanation for the dependence of the read-out heating rate on TL. In chapter 3 a mode for the description of the emission band is described. The construction of a TL facility comprising the TL emission spectrometer is described in chapter 4. Chapter 5 gives an estimation for the possible errors that are made in the data analysis due to imperfect heat transfer from heater to sample. In chapter 6 results of measurements of TL emission spectra of a LiF:Mg, Ti (TLD-100) sample and three LiF:Mg, Ti samples with different impurity concentrations (0-6 ppm Ti and 80-100 ppm Mg) at different read out, annealing procedure and irradiation dose are described. At dose levels less than 22 Gy the emission spectra of the TLD-100 sample and the sample without Ti comprise one emission band at 420 nm and 620 nm, respectively. The TL emission spectra of the other two samples comprise two emission bands at 420 nm and 620 nm. (orig./MM).

A study into the mechanism of thermoluminescence in a LiF:Mg,Ti dosimetry material

International Nuclear Information System (INIS)

Piters, T.M.

1993-01-01

Thermoluminescence (TL) is the phenomenon of light emission from an insulator or semiconductor when it is heated after a previous absorption of energy from ionising radiation. The purpose of the research described in this thesis is to get more insight into the mechanism of TL in LiF:Mg, Ti. In chapter 2 the idea of defect reactions during the readout is introduced as a possible explanation for the dependence of the read-out heating rate on TL. In chapter 3 a mode for the description of the emission band is described. The construction of a TL facility comprising the TL emission spectrometer is described in chapter 4. Chapter 5 gives an estimation for the possible errors that are made in the data analysis due to imperfect heat transfer from heater to sample. In chapter 6 results of measurements of TL emission spectra of a LiF:Mg, Ti (TLD-100) sample and three LiF:Mg, Ti samples with different impurity concentrations (0-6 ppm Ti and 80-100 ppm Mg) at different read out, annealing procedure and irradiation dose are described. At dose levels less than 22 Gy the emission spectra of the TLD-100 sample and the sample without Ti comprise one emission band at 420 nm and 620 nm, respectively. The TL emission spectra of the other two samples comprise two emission bands at 420 nm and 620 nm. (orig./MM)

Nanostructured Li4Ti5O12 synthesized in a reverse micelle: A bridge between pseudocapacitor and lithium ion battery

International Nuclear Information System (INIS)

Wang Wei; Tu Jiguo; Wang Shubo; Hou Jungang; Zhu Hongmin; Jiao Shuqiang

2012-01-01

Nanoparticles of the Li–Ti–O precursors have been prepared using a reverse micelle method. Transmission electron microscopy (TEM) analysis showed that the precursor had an amorphous structure. The average diameter of the amorphous Li–Ti–O particles was approximately 5 nm (within a range of ±2 nm). X-ray diffraction measurement (XRD) results showed that the conversion of the amorphous precursor to crystalline spinel Li 4 Ti 5 O 12 occurred upon a heat treatment at 450 °C in an atmosphere. This is much lower than that for a standard solid-state reaction of Li 2 CO 3 and TiO 2 . An interesting result was that the spinel Li 4 Ti 5 O 12 synthesized at 450 °C, with a particle size of 10–20 nm, had a good pseudocapacitor performance. The charge/discharge testing indicated that the specific capacity, using the activated material of the spinel Li 4 Ti 5 O 12 synthesized at 450 °C, still remained 91 mAh g −1 even at a high charge/discharge rate of 40C after 100 cycles. In comparison, the Li 4 Ti 5 O 12 particles synthesized at 650 °C have been grown to be the size of 50–60 nm, which mostly indicated a battery performance with a remaining specific capacity of 116 mAh g −1 at a charge/discharge rate of 40C over 100 cycles. The significance in this work disclosed that the nanostructured Li 4 Ti 5 O 12 prepared as a reverse micelle could be a bridging material between pseudocapacitor and lithium ion battery.

Microscope Raman scattering and X-ray diffraction study of near-stoichiometric Ti:LiNbO3 waveguides

International Nuclear Information System (INIS)

Zhang, De-Long; Siu, G.G.; Pun, E.Y.B.

2005-01-01

The crystalline phase within guiding layers of near-stoichiometric strip and planar Ti:LiNbO 3 wave-guides, prepared by the method of simultaneous work of vapour transport equilibration (VTE) treatment and indiffusion of Ti film, was studied by combined confocal microscope Raman scattering and X-ray powder diffraction. The results show that the strip and planar waveguide layers still retain the LiNbO 3 phase and no other non-LiNbO 3 phases can be identified within the guiding layer. Li/Nb ratios inside and outside the strip and planar waveguide layers were determined from the microscope Raman scattering results and compared to those obtained from the measured optical absorption edge. It is shown that the Li/Nb ratios are homogeneous within the waveguide layer and are close inside and outside the waveguide layer. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Synthesis and electrochemical properties of Li{sub 2}ZnTi{sub 3}O{sub 8} fibers as an anode material for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Wang Li; Wu Lijuan; Li Zhaohui; Lei Gangtie [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); Xiao Qizhen, E-mail: qizhenxiao2004@yahoo.com.cn [Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Hunan 411105 (China); College of Civil Engineering and Mechanics, Xiangtan University, Hunan 411105 (China); Zhang Ping [College of Civil Engineering and Mechanics, Xiangtan University, Hunan 411105 (China)

2011-06-01

Highlights: > A simple electrospinning method has been developed to fabricate Li{sub 2}ZnTi{sub 3}O{sub 8} fibers. > Li{sub 2}ZnTi{sub 3}O{sub 8} fibers as anode material for lithium-ion batteries. > A stable and reversible capacity of over 227 mAh g{sup -1} is achieved at a rate of 0.1 C. > Li{sub 2}ZnTi{sub 3}O{sub 8} anode exhibits good cycle performance and high rate capability. - Abstract: Li{sub 2}ZnTi{sub 3}O{sub 8} fibers are synthesized by thermally treating electrospun Zn(CH{sub 3}COO){sub 2}/LiOAc/TBT/PVP fibers and utilized as an energy storage material for rechargeable lithium-ion batteries. The material is characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermal analysis. Scanning electron microscopy results show that the Li{sub 2}ZnTi{sub 3}O{sub 8} fibers have an average diameter of 200 nm. Electrochemical properties of the material are evaluated using cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. The results show that as-prepared Li{sub 2}ZnTi{sub 3}O{sub 8} has a high specific discharge capacity of 227.6 mAh g{sup -1} at the 2nd cycle. Its electrochemical performance at subsequent cycles shows good cycling capacity and rate capability. The obtained results thus strongly support that the electrospinning method is an effective method to prepare Li{sub 2}ZnTi{sub 3}O{sub 8} anode material with higher capacity and rate capability.

Solvothermal approach to nanocrystalline Li-Ti-O insertion hosts-solvent polarity effect

Czech Academy of Sciences Publication Activity Database

Kostlánová, Tereza; Makarova, Marina; Krtil, Petr

2008-01-01

Roč. 23, č. 4 (2008), s. 1136-1146 ISSN 0884-2914 Institutional research plan: CEZ:AV0Z40400503 Keywords : lithium cells * LiTi2O4 * oxides Subject RIV: CG - Electrochemistry Impact factor: 1.743, year: 2008

Preparation of Li4Ti5O12 by solution ion-exchange of sodium titanate nanotube and evaluation of electrochemical performance

International Nuclear Information System (INIS)

Zhang, Jingwei; Zhang, Fenli; Li, Jiuhe; Cai, Wei; Zhang, Jiwei; Yu, Laigui; Jin, Zhensheng; Zhang, Zhijun

2013-01-01

Nano-sized spinel lithium titanate (Li 4 Ti 5 O 12 ) was synthesized using sodium titanate nanotube as precursor via a facile solution ion-exchange method in association with subsequent calcination treatment at relatively low temperature. The influences of precursors, ion-exchange condition, and calcination temperature on the microstructure and electrochemical performance of the products were studied. Results indicate that pure-phase Li 4 Ti 5 O 12 can be harvested from sodium titanate nanotube precursor through an ion-exchanging at room temperature and calcination at 500 °C. The products exhibit a better performance as Li-ion battery anode material than the counterparts prepared from protonic titanate nanotube (H-titanate) precursor. The reason may lie in that sodium titanate nanotube is easier than protonic titanate nanotube to synthesize lithium titanate without TiO 2 impurity, resulting in reduced electron transfer ability and Li-ion transport ability. The capacity of Li 4 Ti 5 O 12 prepared from sodium titanate nanotube is 146 mAh/g at 10 C, and it has only 0.7 % decay after 200 charge/discharge cycles

Optimized dispersion of conductive agents for enhanced Li-storage performance of TiO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Han, Moyan; Chen, Ge, E-mail: chenge@bjut.edu.cn

2016-12-01

Highlights: • A novel TiO{sub 2}/carbon (TiO{sub 2}/C) composite has been synthesized by a layer-by-layer deposition method combined with electrostatic interaction. • As anode materials for Li-ion batteries, the TiO{sub 2}/C composites exhibit excellent rate capability and cycling stability. • The enhanced electrochemical performance may be attributed to the well-dispersed carbon conductive framework. - Abstract: Novel TiO{sub 2}/carbon (TiO{sub 2}/C) composites have been synthesized by a layer-by-layer deposition method, with electrostatic interaction. The addition of carbon conductive agents enhances the electrochemical performance of TiO{sub 2}. Carbon for these has been sourced 0D nitrogen-doped carbon, 1D carbon nanotubes and 2D graphene. The as-obtained TiO{sub 2}/C composites show carbon nanotubes and titanium dioxide coaxial nanocables anchored on the graphene. The nitrogen-doped carbon is uniformly dispersed on the nanocables. As anode materials for Li-ion batteries, the TiO{sub 2}/C composites exhibit excellent rate capability and cycling stability. A capacity of 150 mAh/g is retained at a current density of 4 A/g. The enhanced electrochemical performance may be attributed to the well-dispersed carbon conductive framework, which facilitates charge transfer during the lithium insertion/extraction process.

Robust Strategy for Crafting Li5Cr7Ti6O25@CeO2 Composites as High-Performance Anode Material for Lithium-Ion Battery.

Science.gov (United States)

Mei, Jie; Yi, Ting-Feng; Li, Xin-Yuan; Zhu, Yan-Rong; Xie, Ying; Zhang, Chao-Feng

2017-07-19

A facile strategy was developed to prepare Li 5 Cr 7 Ti 6 O 25 @CeO 2 composites as a high-performance anode material. X-ray diffraction (XRD) and Rietveld refinement results show that the CeO 2 coating does not alter the structure of Li 5 Cr 7 Ti 6 O 25 but increases the lattice parameter. Scanning electron microscopy (SEM) indicates that all samples have similar morphologies with a homogeneous particle distribution in the range of 100-500 nm. Energy-dispersive spectroscopy (EDS) mapping and high-resolution transmission electron microscopy (HRTEM) prove that CeO 2 layer successfully formed a coating layer on a surface of Li 5 Cr 7 Ti 6 O 25 particles and supplied a good conductive connection between the Li 5 Cr 7 Ti 6 O 25 particles. The electrochemical characterization reveals that Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode shows the highest reversibility of the insertion and deinsertion behavior of Li ion, the smallest electrochemical polarization, the best lithium-ion mobility among all electrodes, and a better electrochemical activity than the pristine one. Therefore, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) electrode indicates the highest delithiation and lithiation capacities at each rate. At 5 C charge-discharge rate, the pristine Li 5 Cr 7 Ti 6 O 25 only delivers an initial delithiation capacity of ∼94.7 mAh g -1 , and the delithiation capacity merely achieves 87.4 mAh g -1 even after 100 cycles. However, Li 5 Cr 7 Ti 6 O 25 @CeO 2 (3 wt %) delivers an initial delithiation capacity of 107.5 mAh·g -1 , and the delithiation capacity also reaches 100.5 mAh g -1 even after 100 cycles. The cerium dioxide modification is a direct and efficient approach to improve the delithiation and lithiation capacities and cycle property of Li 5 Cr 7 Ti 6 O 25 at large current densities.

The determination of kinetic parameters of LiF : Mg,Ti from thermal decaying curves of optical absorption bands

CERN Document Server

Yazici, A N

2003-01-01

In this paper, the thermal bleaching curves (TBCs) of specific optical absorption bands of LiF : Mg,Ti were measured as a function of temperature. The TBCs obtained were analysed to extract the kinetic parameters (the thermal activation energy (E) and the frequency factor (s)) of some TL glow peaks of LiF : Mg,Ti on the basis of the developed first-order kinetic model over a specified temperature region.

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.

Lithium-Excess Research of Cathode Material Li2MnTiO4 for Lithium-Ion Batteries

OpenAIRE

Zhang, Xinyi; Yang, Le; Hao, Feng; Chen, Haosen; Yang, Meng; Fang, Daining

2015-01-01

Lithium-excess and nano-sized Li2+xMn1−x/2TiO4 (x = 0, 0.2, 0.4) cathode materials were synthesized via a sol-gel method. The X-ray diffraction (XRD) experiments indicate that the obtained main phases of Li2.0MnTiO4 and the lithium-excess materials are monoclinic and cubic, respectively. The scanning electron microscope (SEM) images show that the as-prepared particles are well distributed and the primary particles have an average size of about 20–30 nm. The further electrochemical tests revea...

Energy dependence of thermoluminescent response of CaSO{sub 4}:Dy, LiF:Mg and micro LiF:Mg,Ti in clinical beams of electrons by using different simulator objects; Dependencia energetica da resposta TL de dosimetros de CaSO{sub 4}:Dy, LiF:Mg e microLiF:Mg,Ti em feixes clinicos de eletrons utilizando diferentes objetos simuladores

Energy Technology Data Exchange (ETDEWEB)

Bravim, Amanda; Campos, Leticia Lucente, E-mail: abravin@ipen.b, E-mail: rsakuraba@einstein.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sakuraba, Roberto K.; Cruz, Jose Carlos da, E-mail: rsakuraba@einstein.b, E-mail: josecarlosc@einstein.b [Hospital Israelita Albert Einstein (HIAE), Sao Paulo, SP (Brazil)

2011-10-26

Yet not so widely applied in radiotherapy, the calcium sulfate doped with dysprosium (CaSO{sub 4}:Dy) is used in radioprotection and studies has been demonstrated its great potential for the dosimetry in radiotherapy. This work evaluates the energy dependence of the thermoluminescent answer of the CaSO{sub 4}:D, LiF:Mg,Ti (TLD-100) and micro LiF:Mg,Ti in clinical beams of electrons by using water simulators, PMMA and solid water

Electrochemical properties of rapidly solidified Si-Ti-Ni(-Cu) base anode for Li-ion rechargeable batteries

Science.gov (United States)

Kwon, Hye Jin; Sohn, Keun Yong; Park, Won-Wook

2013-11-01

In this study, rapidly solidified Si-Ti-Ni-Cu alloys have been investigated as high capacity anodes for Li-ion secondary batteries. To obtain nano-sized Si particles dispersed in the inactive matrix, the alloy ribbons were fabricated using the melt spinning process. The thin ribbons were pulverized using ball-milling to make a fine powder of ˜ 4 µm average size. Coin-cell assembly was carried out under an argon gas in a glove box, in which pure lithium was used as a counter-electrode. The cells were cycled using the galvanostatic method in the potential range of 0.01 V and 1.5 V vs. Li/Li+. The microstructure and morphology were examined using an x-ray diffractometer, Field-Emission Scanning Electron Microscopy and High Resolution Transmission Electron Microscopy. Among the anode alloys, the Si70Ti15Ni15 electrodes had the highest discharge capacity (974.1 mAh/g) after the 50th cycle, and the Si60Ti16Ni16Cu8 electrode showed the best coulombic efficiency of ˜95.9% in cyclic behavior. It was revealed that the Si7Ni4Ti4 crystal phase coexisting with an amorphous phase, could more efficiently act as a buffer layer than the fully crystallized Si7Ni4Ti4 phase. Consequently, the electrochemical properties of the anode materials pronouncedly improved when the nano-sized primary Si particle was dispersed in the inactive Si7Ni4Ti4-based matrix mixed with an amorphous structure.

Eco-friendly synthesis of core-shell structured (TiO2/Li2CO3) nanomaterials for low cost dye-sensitized solar cells.

Science.gov (United States)

Karuppuchamy, S; Brundha, C

2016-12-01

Core-shell structured TiO 2 /Li 2 CO 3 electrode was successfully synthesized by eco-friendly solution growth technique. TiO 2 /Li 2 CO 3 electrodes were characterized using X-ray Diffractometer (XRD), Scanning electron microscopy (SEM) and photocurrent-voltage measurements. The synthesized core-shell electrode material was sensitized with tetrabutylammonium cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine)ruthenate(II) (N-719). The performance of dye-sensitized solar cells (DSCs) based on N719 dye modified TiO 2 /Li 2 CO 3 electrodes was investigated. The effect of various shell thickness on the photovoltaic performance of the core-shell structured electrode is also investigated. We found that Li 2 CO 3 shells of all thicknesses perform as inert barriers which improve open-circuit voltage (V oc ) of the DSCs. The energy conversion efficiency was greatly dependent on the thickness of Li 2 CO 3 on TiO 2 film, and the highest efficiency of 3.7% was achieved at the optimum Li 2 CO 3 shell layer. Copyright © 2015 Elsevier Inc. All rights reserved.

Synthesis and Piezoelectric Properties of Li, Ca and Mn-codoped BaTiO3 by a Solvothermal Approach

International Nuclear Information System (INIS)

Kimura, T; Dong, Q; Yin, S; Sato, T; Hashimoto, T; Sasaki, A; Aisawa, S

2013-01-01

3 at.% Li-doped (Ba 1-x Ca x )(Ti 1-y Mn y )O 3 particles with the Ca 2+ mole fraction, x, of 0–0.09 and Mn mole fraction, y, of 0 and 0.0005 were synthesized by a solvothermal approach at 200°C. The products consisted of nanoparticles of 50–100 nm in diameter, and did not change very much depending on the amount of Li, Ca and Mn-codoping. The change in relative dielectric constant, Δε r , in around room temperature decreased by doping Ca 2+ , and the lowest Δε r (4.51%) could be realized at x value of 0.03. The mechanical quality factor, Q m , of 3 at.% Li-doped (Ba 0.97 Ca 0.03 )(Ti 0.9995 Mn 0.0005 )O 3 increased to 521, and Δε r decreased to 1.72%, while the piezoelectric constant, d 33 (234pC/N), and electromechanical coupling factor, k p (40.0%), did not change very much compared with 3 at.% Li-doped BaTiO 3

High rate performance of the carbon encapsulated Li4Ti5O12 for lithium ion battery

Directory of Open Access Journals (Sweden)

Qi Cheng

Full Text Available Li4Ti5O12 (LTO is attractive alternative anode material with excellent cyclic performance and high rate after coating modifications of the conductive materials. Anatase TiO2 and glucose were applied of the synthesis of the carbon coated LTO (C@LTO. XRD results showed that all the major diffractions from the spinel structure of LTO can be found in the C@LTO such as (111, (311, (400 but there are no observations of the Carbon diffraction peaks. Electrochemical Impedance Spectroscopy (EIS data shows C@LTO resistance was nearly half of the LTO value. Rate performance showed that capacity of C@LTO was higher than that of the pure LTO from 0.1 C, 0.2 C, 1 C, 2 C, 5 C and 10 C, which indicates that this is a promising approach to prepare the high performance LTO anode. Keywords: Li-ion batteries, Rate performance, Carbon materials, Li4Ti5O12 anode

Enhanced Charge Extraction of Li-Doped TiO2 for Efficient Thermal-Evaporated Sb2S3 Thin Film Solar Cells

Science.gov (United States)

Lan, Chunfeng; Luo, Jingting; Lan, Huabin; Fan, Bo; Peng, Huanxin; Zhao, Jun; Sun, Huibin; Zheng, Zhuanghao; Liang, Guangxing; Fan, Ping

2018-01-01

We provided a new method to improve the efficiency of Sb2S3 thin film solar cells. The TiO2 electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb2S3 solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO2 films. Compared with the undoped TiO2, Li-doped mesoporous TiO2 dramatically improved the photo-voltaic performance of the thermal-evaporated Sb2S3 thin film solar cells, with the average power conversion efficiency (PCE) increasing from 1.79% to 4.03%, as well as the improved open-voltage (Voc), short-circuit current (Jsc) and fill factors. The best device based on Li-doped TiO2 achieved a power conversion efficiency up to 4.42% as well as a Voc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb2S3 solar cells. This study showed that Li-doping on TiO2 can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb2S3-based solar cells. PMID:29495612

Enhanced Charge Extraction of Li-Doped TiO2 for Efficient Thermal-Evaporated Sb2S3 Thin Film Solar Cells

Directory of Open Access Journals (Sweden)

Chunfeng Lan

2018-02-01

Full Text Available We provided a new method to improve the efficiency of Sb2S3 thin film solar cells. The TiO2 electron transport layers were doped by lithium to improve their charge extraction properties for the thermal-evaporated Sb2S3 solar cells. The Mott-Schottky curves suggested a change of energy band and faster charge transport in the Li-doped TiO2 films. Compared with the undoped TiO2, Li-doped mesoporous TiO2 dramatically improved the photo-voltaic performance of the thermal-evaporated Sb2S3 thin film solar cells, with the average power conversion efficiency (PCE increasing from 1.79% to 4.03%, as well as the improved open-voltage (Voc, short-circuit current (Jsc and fill factors. The best device based on Li-doped TiO2 achieved a power conversion efficiency up to 4.42% as well as a Voc of 0.645 V, which are the highest values among the reported thermal-evaporated Sb2S3 solar cells. This study showed that Li-doping on TiO2 can effectively enhance the charge extraction properties of electron transport layers, offering a new strategy to improve the efficiency of Sb2S3-based solar cells.

Electrochemically active nanocomposites of Li4Ti5O12 2D nanosheets and SnO2 0D nanocrystals with improved electrode performance

International Nuclear Information System (INIS)

Han, Song Yi; Kim, In Young; Lee, Sang-Hyup; Hwang, Seong-Ju

2012-01-01

Electrochemically active nanocomposites consisting of Li 4 Ti 5 O 12 2D nanosheets and SnO 2 0D nanocrystals are synthesized by the crystal growth of tin dioxide on the surface of 2D nanostructured lithium titanate. According to powder X-ray diffraction and electron microscopic analyses, the rutile-structured SnO 2 nanocrystals are stabilized on the surface of spinel-structured Li 4 Ti 5 O 12 2D nanosheets. The homogeneous hybridization of tin dioxide with lithium titanate is confirmed by elemental mapping analysis. Ti K-edge X-ray absorption near-edge structure and Sn 3d X-ray photoelectron spectroscopy indicate the stabilization of tetravalent titanium ions in the spinel lattice of Li 4 Ti 5 O 12 and the formation of SnO 2 phase with tetravalent Sn oxidation state. The electrochemical measurements clearly demonstrate the promising functionality of the present nanocomposites as anode for lithium secondary batteries. The Li 4 Ti 5 O 12 –SnO 2 nanocomposites show larger discharge capacity and better cyclability than do the uncomposited Li 4 Ti 5 O 12 and SnO 2 phases, indicating the synergistic effect of nanocomposite formation on the electrode performance of Li 4 Ti 5 O 12 and SnO 2 . The present experimental findings underscore the validity of 2D nanostructured lithium titanate as a useful platform for the stabilization of nanocrystalline electrode materials and also for the improvement of their functionality.

Properties of the 4.45 eV optical absorption band in LiF:Mg, Ti

International Nuclear Information System (INIS)

Nail, I.; Oster, L.; Horowitz, Y. S.; Biderman, S.; Belaish, Y.

2006-01-01

The optical absorption (OA) and thermoluminescence (TL) of dosimetric LiF:Mg,Ti (TLD-100) as well as nominally pure LiF single crystal have been studied as a function of irradiation dose, thermal and optical bleaching in order to investigate the role of the 4.45 eV OA band in low temperature TL. Computerised deconvolution was used to resolve the absorption spectrum into individual gaussian bands and the TL glow curve into glow peaks. Although the 4.45 eV OA band shows thermal decay characteristics similar to the 4.0 eV band its dose filling constant and optical bleaching properties suggest that it cannot be associated with the TL of composite peaks 4 or 5. Its presence in optical grade single crystal LiF further suggests that it is an intrinsic defect or possibly associated with chance impurities other than Mg, Ti. (authors)

Recovery and recycling of lithium value from spent lithium titanate (Li{sub 2}TiO{sub 3}) pebbles

Energy Technology Data Exchange (ETDEWEB)

Mandal, D., E-mail: dmandal10@gmail.com

2013-09-15

Graphical abstract: Effects of various process parameters on the recovery of Li-from spent Li{sub 2}TiO{sub 3} pebbles were investigated. From the experimental results it was observed that the leaching rate increases with speed of stirring till 450 rpm and then above 450 rpm; the increase in speed of stirring does not have any significant effect on the leaching rate as shown in the following figure. Effects of other parameters on the Li-recovery from spent Li{sub 2}TiO{sub 3} pebbles are discussed in this paper. Abstract: In the first generation fusion reactors the fusion of deuterium (D) and tritium (T) is considered to produce energy to meet the future energy demand. Deuterium is available in nature whereas, tritium is not. Lithium-6 (Li{sup 6}) isotope has the ability to produce tritium in the n, α nuclear reaction with neutrons. Thus lithium-based ceramics enriched by Li{sup 6} isotope are considered for the tritium generation for its use in future fusion reactors. Lithium titanate is one such Li-based ceramic material being considered for its some attractive properties viz., high thermal and chemical stability, high thermal conductivity, and low tritium solubility. It is reported in the literature, that the burn up of these pebbles in the fusion reactor will be limited to only 15–17 atomic percentage. At the end of life, the pebbles will contain more than 45% unused Li{sup 6} isotope. Due to the high cost of enriched Li{sup 6} and the waste disposal considerations, it is necessary to recover the unused Li from the spent lithium titanate pebbles. Till date, only the feasibilities of different processes are reported, but no process details are available. Experiments were carried out for the recovery of Li from simulated Li{sub 2}TiO{sub 3} pebbles and to reuse of lithium in lithium titanate pebble fabrication. The details of the experiments and results are discussed in this paper.

Carbon coated nano-LiTi2(PO4)3 electrodes for non-aqueous hybrid supercapacitors.

Science.gov (United States)

Aravindan, V; Chuiling, W; Reddy, M V; Rao, G V Subba; Chowdari, B V R; Madhavi, S

2012-04-28

The Pechini type polymerizable complex decomposition method is employed to prepare LiTi(2)(PO(4))(3) at 1000 °C in air. High energy ball milling followed by carbon coating by the glucose-method yielded C-coated nano-LiTi(2)(PO(4))(3) (LTP) with a crystallite size of 80(±5) nm. The phase is characterized by X-ray diffraction, Rietveld refinement, thermogravimetry, SEM, HR-TEM and Raman spectra. Lithium cycling properties of LTP show that 1.75 moles of Li (~121 mA h g(-1) at 15 mA g(-1) current) per formula unit can be reversibly cycled between 2 and 3.4 V vs. Li with 83% capacity retention after 70 cycles. Cyclic voltammograms (CV) reveal the two-phase reaction mechanism during Li insertion/extraction. A hybrid electrochemical supercapacitor (HEC) with LTP as negative electrode and activated carbon (AC) as positive electrode in non-aqueous electrolyte is studied by CV at various scan rates and by galvanostatic cycling at various current rates up to 1000 cycles in the range 0-3 V. Results show that the HEC delivers a maximum energy density of 14 W h kg(-1) and a power density of 180 W kg(-1). This journal is © the Owner Societies 2012

Characterization of Al-Ti phases in cycled TiF{sub 3}-enhanced Na{sub 2}LiAlH{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Y. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)]. E-mail: yumikon@ife.no; Fossdal, A. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway); Brinks, H.W. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, B.C. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)

2006-06-08

TiF{sub 3}-enhanced Na{sub 2}LiAlH{sub 6} was investigated after dehydrogenation-hydrogenation cycles by synchrotron X-ray diffraction. There was no sign of Ti after ball-milling with TiF{sub 3}, but two types of Al-Ti phases were observed in the cycled samples. In a sample after measuring five pressure-composition isotherms in the temperature range from 170 to 250 deg. C, a fcc phase with a = 3.987 A was observed. This phase is considered to be Al{sub 3}Ti with the L1{sub 2} structure. Samples after one or four cycles at selected temperatures between 170 and 250 deg. C showed diffraction from another fcc phase with a {approx} 4.03 A. This indicates formation of an Al{sub 1-y}Ti {sub y} solid-solution phase with y {approx} 0.15 similar to previously reported for cycled NaAlH{sub 4} with Ti additives.

Magnéli phases Ti{sub 4}O{sub 7} and Ti{sub 8}O{sub 15} and their carbon nanocomposites via the thermal decomposition-precursor route

Energy Technology Data Exchange (ETDEWEB)

Conze, S., E-mail: susan.conze@ikts.fraunhofer.de [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Winterbergstr. 28, 01277 Dresden (Germany); Veremchuk, I. [Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden (Germany); Reibold, M. [Technical University of Dresden, Zum Triebenberg 50, 01328 Dresden (Zaschendorf) (Germany); Matthey, B.; Michaelis, A. [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Winterbergstr. 28, 01277 Dresden (Germany); Grin, Yu. [Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden (Germany); Kinski, I. [Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Winterbergstr. 28, 01277 Dresden (Germany)

2015-09-15

A new synthetic approach for producing nano-powders of the Magnéli phases Ti{sub 4}O{sub 7}, Ti{sub 8}O{sub 15} and their carbon nanocomposites by thermal decomposition-precursor route is proposed. The formation mechanism of the single-phase carbon nanocomposites (Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C) from metal–organic precursors is studied using FT-IR, elemental analysis, TG, STA-MS and others. The synthesis parameters and conditions were optimized to prepare the target oxides with the desired microstructure and physical properties. The electrical and transport properties of Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C are investigated. These nano-materials are n-type semiconductors with relatively low thermal conductivity in contrast to the bulk species. The nanostructured carbon nanocomposites of Magnéli phases achieve a low thermal conductivity close to 1 W/m K at RT. The maximum ZT{sub 570} {sub °C} values are 0.04 for Ti{sub 4}O{sub 7}/C powder nanocomposite and 0.01 for Ti{sub 8}O{sub 15}/C bulk nanocomposite. - Graphical abstract: From the precursor to the produced titanium oxide pellet and its microstructure (SEM, TEM micrographs) as well as results of phase and thermoelectric analyses. - Highlights: • Magnéli phases Ti{sub 4}O{sub 7}/Ti{sub 8}O{sub 15} via thermal decomposition-precursor route is proposed. • The formation mechanism of the nanocomposites Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C are investigated. • Microstructure of Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C are examined. • The electrical and transport properties of Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C are investigated. • The maximum figure of mertit ZT{sub 570} {sub °C} of Ti{sub 4}O{sub 7}/C and Ti{sub 8}O{sub 15}/C are 0.01 and 0.04.

Cycling Performance of Li4Ti5O12 Electrodes in Ionic Liquid-Based Gel Polymer Electrolytes

International Nuclear Information System (INIS)

Kim, Jin Hee; Kim, Dong Won; Kang, Yong Ku

2012-01-01

We investigated the cycling behavior of Li 4 Ti 5 O 12 electrode in a cross-linked gel polymer electrolyte based on non-flammable ionic liquid consisting of 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide and vinylene carbonate. The Li 4 Ti 5 O 12 electrodes in ionic liquid-based gel polymer electrolytes exhibited reversible cycling behavior with good capacity retention. Cycling data and electrochemical impedance spectroscopy analyses revealed that the optimum content of the cross-linking agent necessary to ensure both acceptable initial discharge capacity and good capacity retention was about 8 wt %

Fabrication of Li4Ti5O12-TiO2 Nanosheets with Structural Defects as High-Rate and Long-Life Anodes for Lithium-Ion Batteries.

Science.gov (United States)

Xu, Hui; Chen, Jian; Li, Yanhuai; Guo, Xinli; Shen, Yuanfang; Wang, Dan; Zhang, Yao; Wang, Zengmei

2017-06-07

Development of high-power lithium-ion batteries with high safety and durability has become a key challenge for practical applications of large-scale energy storage devices. Accordingly, we report here on a promising strategy to synthesize a high-rate and long-life Li 4 Ti 5 O 12 -TiO 2 anode material. The novel material exhibits remarkable rate capability and long-term cycle stability. The specific capacities at 20 and 30 C (1 C = 175 mA g -1 ) reach 170.3 and 168.2 mA h g -1 , respectively. Moreover, a capacity of up to 161.3 mA h g -1 is retained after 1000 cycles at 20 C, and the capacity retention ratio reaches up to 94.2%. The extraordinary rate performance of the Li 4 Ti 5 O 12 -TiO 2 composite is attributed to the existence of oxygen vacancies and grain boundaries, significantly enhancing electrical conductivity and lithium insertion/extraction kinetics. Meanwhile, the pseudocapacitive effect is induced owing to the presence of abundant interfaces in the composite, which is beneficial to enhancing specific capacity and rate capability. Additionally, the ultrahigh capacity at low rates, greater than the theoretical value of spinel Li 4 Ti 5 O 12 , may be correlated to the lithium vacancies in 8a sites, increasing the extra docking sites of lithium ions.

Improved electrochemical performance of Li4Ti5O12 with a variable amount of graphene as a conductive agent for rechargeable lithium-ion batteries by solvothermal method

International Nuclear Information System (INIS)

Rai, Alok Kumar; Gim, Jihyeon; Kang, Sung-Won; Mathew, Vinod; Anh, Ly Tuan; Kang, Jungwon; Song, Jinju; Paul, Baboo Joseph; Kim, Jaekook

2012-01-01

We report on the solvothermal preparation of pure Li 4 Ti 5 O 12 and Li 4 Ti 5 O 12 /graphene (15 wt% and 30 wt%) nanocomposites anode for high-performance lithium-ion batteries. Structure and morphology studies of the nanocomposites by X-ray diffraction, field-emission scanning electron microscopy and field-emission transmission electron microscopy reveal Li 4 Ti 5 O 12 nanoparticles embedded onto the graphene nanosheets. On comparison to pure spinel Li 4 Ti 5 O 12 , the electrochemical performances of the Li 4 Ti 5 O 12 /graphene nanocomposites indicate higher capacities and enhanced cycle performances within the voltage domain of 1.0–2.5 V, under current rates as high as 10.4 C. The production of phase pure Li 4 Ti 5 O 12 nanoparticles ensures the short ion-diffusion paths while the presence of graphene facilitates improved structural network and hence enhanced electronic transport in the prepared nanocomposites. These factors eventually amount to impressive electrochemical properties. Highlights: ► A simple polyol-based approach to obtain the graphene nanosheets. ► Li 4 Ti 5 O 12 /graphene nanocomposites synthesis by polyol-based solvothermal process. ► Low temperature solvothermal strategy is one-step process to control nanoparticle sizes. ► The nanoparticles are well anchored onto the graphene nanosheets in the nanocomposites. ► Li 4 Ti 5 O 12 /graphene nanocomposites exhibit impressive electrochemical performances.

Li insertion into Li4Ti5O12 spinel prepared by low temperature solid state route: Charge capability vs surface area

Czech Academy of Sciences Publication Activity Database

Zukalová, Markéta; Fabián, M.; Klusáčková, Monika; Klementová, Mariana; Pitňa Lásková, Barbora; Danková, Z.; Senna, M.; Kavan, Ladislav

2018-01-01

Roč. 265 (2018), s. 480-487 ISSN 0013-4686 R&D Projects: GA ČR GA15-06511S; GA MŠk LM2015087; GA MŠk 8F15003 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Li4Ti5O12 * Charge capacity * Solid state * Li insertion * Surface area Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 4.798, year: 2016

Effect of oxygen vacancies on Li-storage of anatase TiO2 (001 ...

Indian Academy of Sciences (India)

2018-03-29

Mar 29, 2018 ... (a–d) Top and side views of the optimum structure of anatase TiO2 (001) surfaces adsorbing a single Li .... Rate capability is an important requirement for a promis- .... tific Research Foundation of Hunan Provincial Education.

STUDY OF THE INSERTION AND EXTRACTION MECHANISM OF Li3Mn0.5Ti0.25O3

Directory of Open Access Journals (Sweden)

JINHE JIANG

2017-12-01

Full Text Available The metal oxide [Li3Mn0.5Ti0.25O3] was synthesized by solid state reaction crystallization method in certain temperature. It was an inverse spinel type compound metal oxide. The extraction/insertion reaction of this material was studied by X-ray, saturation exchange capacity value and distribution coefficient (Kd measurement value. In terms of its composition and chemical metrology, this inverse spinel material is very comprehensive; it is worth noting that it can be inserted or extracted by other substitutional ions and changes in lithium and oxygen stoichiometry while maintaining their crystal structure. The metal oxide [Li3Mn0.5Ti0.25O3] is inorganic Li+ exchanger which has an ion-memory capacity. It has high exchange selectivity ability for Li+. This metal oxide can be used to separate or extract Li+ in aqueous solution. The experimental result has confirmed inverse spinel type compound metal oxide which was treated by acid could attain 9.7 mmol‧g-1 Li+ exchanged capacity.

Ferroelectric BaTiO3 and LiNbO3 Nanoparticles Dispersed in Ferroelectric Liquid Crystal Mixtures: Electrooptic and Dielectric (Postprint)

Science.gov (United States)

2016-10-14

strength for non- doped LF4 and LiNbO3/LF4 nanocolloids at temperature 30C. 146 R. K . SHUKLA ET AL. 6 Distribution A. Approved for public release (PA...AFRL-RX-WP-JA-2017-0210 FERROELECTRIC BaTiO3 AND LiNbO3 NANOPARTICLES DISPERSED IN FERROELECTRIC LIQUID CRYSTAL MIXTURES: ELECTROOPTIC...COMMAND UNITED STATES AIR FORCE Ferroelectric BaTiO3 and LiNbO3 nanoparticles dispersed in ferroelectric liquid crystal mixtures: Electrooptic and

Thermal desensitization of gamma irradiated LiF:Mg,Ti

Energy Technology Data Exchange (ETDEWEB)

Chernov, V.; Rogalev, B.; Afonin, G. (Institute of Geochemistry, Irkutsk (Russian Federation))

1993-01-01

The thermoluminescence sensitivity variation of gamma irradiated LiF:Mg,Ti after annealing at temperatures of 300-500[sup o]C has been studied. This variation is shown to be due to concurrent processes of sensitization and damage. Annealing of irradiated crystals leads to the restoration of the initial sensitivity. The damage decay time is approximately an order of magnitude greater than the decay time of the sensitization. The experimental data are interpreted quantitatively within the scope of included gamma track overlapping. (author).

Effect of freeze-drying and self-ignition process on the microstructural and electrochemical properties of Li{sub 4}Ti{sub 5}O{sub 12}

Energy Technology Data Exchange (ETDEWEB)

Jamin, Claire [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Traina, Karl [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Eskenazi, David [Chemical Engineering Laboratory, Department of Applied Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Krins, Natacha; Cloots, Rudi; Vertruyen, Bénédicte [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Boschini, Frédéric, E-mail: frederic.boschini@ulg.ac.be [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium)

2013-11-15

Graphical abstract: - Highlights: • Li{sub 4}Ti{sub 5}O{sub 12} is prepared by a method involving self-ignition of a freeze-dried gel. • Addition of NH{sub 4}NO{sub 3} modifies the self-ignition propagation mode. • Well-crystallized Li{sub 4}Ti{sub 5}O{sub 12} phase is obtained after only 2 h at 800 °C. • Li{sub 4}Ti{sub 5}O{sub 12} powder has 161 mAh g{sup −1} capacity and good retention at C/4 rate. - Abstract: Crystalline Li{sub 4}Ti{sub 5}O{sub 12} is synthesized by a method involving the freeze-drying and self-ignition of a gel prepared from titanium isopropoxide, lithium nitrate and hydroxypropylmethylcellulose (HPMC). This synthesis route yields crystalline Li{sub 4}Ti{sub 5}O{sub 12} particles after calcination at 800 °C for 2 h. In an alternative route, addition of ammonium nitrate shifts the self-ignition mode from wave-like propagation to simultaneous. Powders with different microstructures are thereby obtained. Electrochemical characterization shows that the best results for Li{sup +} intercalation/desintercalation are obtained for the powder prepared without ammonium nitrate addition. These results highlight the necessity for a control of the self-ignition mode to obtain adequate properties.

On the synthesis, characterization, rationalization of the structure and the compositional formula of Ti-substituted Li0,5Fe2,5O4

International Nuclear Information System (INIS)

Widatallah, H.M.; Berry, F.J.; Moore, E.A.; Johnson, C.; Jartych, E.; Pekala, M.; Grabski, J.

2002-12-01

Spinel-related titanium-substituted Li 0.5 Fe 2.5 O 4 has been synthesised by heating a mixture of titanium-doped corundum-related α-Fe 2 O 3 with Li 2 CO 3 at 850 deg C which is ca. 250-350 deg C lower than temperatures at which the material is normally prepared conventionally. Moessbauer and magnetic measurements imply that the Ti 4+ ions substitute for octahedral Fe 3+ ions. Interatomic potential calculations support this substitution with the charge balance being maintained by Li + vacancies. This structural model leads to a compositional formula of the type Li (0.5-x) + Ti x 4+ Fe (2.5-x) 3+ O 4 which is shown to be more appropriate than the one generally used in the literature, namely Li (0.5+0.5x) + Ti x 4+ Fe (2.5-1.5x) 3+ O 4 . Some implications of the suggested formula are discussed including the possibility of the existence of a thermodynamically stable titanium ferrite of the form Ti 0.5 Fe 2 O 4 . (author)

Direct synthesis of pure single-crystalline Magnéli phase Ti8O15 nanowires as conductive carbon-free materials for electrocatalysis

Science.gov (United States)

He, Chunyong; Chang, Shiyong; Huang, Xiangdong; Wang, Qingquan; Mei, Ao; Shen, Pei Kang

2015-02-01

The Magnéli phase Ti8O15 nanowires (NWs) have been grown directly on a Ti substrate by a facile one-step evaporation-deposition synthesis method under a hydrogen atmosphere. The Ti8O15 NWs exhibit an outstanding electrical conductivity at room temperature. The electrical conductivity of a single Ti8O15 nanowire is 20.6 S cm-1 at 300 K. Theoretical calculations manifest that the existence of a large number of oxygen vacancies changes the band structure, resulting in the reduction of the electronic resistance. The Magnéli phase Ti8O15 nanowires have been used as conductive carbon-free supports to load Pt nanoparticles for direct methanol oxidation reaction (MOR). The Pt/Ti8O15 NWs show an enhanced activity and extremely high durability compared with commercial Pt/C catalysts.The Magnéli phase Ti8O15 nanowires (NWs) have been grown directly on a Ti substrate by a facile one-step evaporation-deposition synthesis method under a hydrogen atmosphere. The Ti8O15 NWs exhibit an outstanding electrical conductivity at room temperature. The electrical conductivity of a single Ti8O15 nanowire is 20.6 S cm-1 at 300 K. Theoretical calculations manifest that the existence of a large number of oxygen vacancies changes the band structure, resulting in the reduction of the electronic resistance. The Magnéli phase Ti8O15 nanowires have been used as conductive carbon-free supports to load Pt nanoparticles for direct methanol oxidation reaction (MOR). The Pt/Ti8O15 NWs show an enhanced activity and extremely high durability compared with commercial Pt/C catalysts. Electronic supplementary information (ESI) available: Additional data for the characterization and experimental details see DOI: 10.1039/c4nr05806b

Comparative study of thermoluminescent properties of LiF: Mg, Cu, P, LiF: Mg, Ti and TLD-100 irradiated with X-rays

International Nuclear Information System (INIS)

Azorin, J.; Rivera, T.; Gonzalez, P.; Ortega, X.; Ginjaume, M.

2000-01-01

The thermoluminescent properties (Tl) of LiF: Mg, Cu, P, and LiF: Mg, Ti, were investigated both developed in Mexico and comparing them with the properties of TLD-100 when they are exposure to X-rays. The Tl curve of LiF: Mg, Cu, P exhibited two peaks at 200 and 300 Centigrade. Its response Tl in function of dose resulted linear in the interval of 0.5 Gy until 5 Gy and its sensitivity to X-ray was around 25 times greater that of the TLD-100. Also it was measured the Tl response of the three materials in function of photon energy. The results showed that LiF: Mg, Cu, P has potential to be used as X-ray dosemeter. (Author)

Aging behavior of an in-situ TiB2/Al-Cu-Li-x matrix composite

International Nuclear Information System (INIS)

Shen, Yanwei; Hong, Tianran; Geng, Jiwei; Han, Gaoyang; Chen, Dong; Li, Xianfeng; Wang, Haowei

2017-01-01

Transmission electron microscopy, differential scanning calorimetry and hardness tests have been performed on an in-situ TiB 2 /Al-3.3Cu-1.0Li-0.60Mg-0.40Ag-0.14Zr-0.13Si composite to study its aging behavior at 175 °C. A cubic phase suspected to be the σ (Al 5 Cu 6 Mg 2 ) phase or its variant is precipitated at all aging stages studied, and this phase is not typically observed in the Al-Cu-Li alloys. The primary hardening (aging for 3 h) phases consist of δ′ (Al 3 Li), β′ (Al 3 Zr) and the cubic phase. After aging for 18 h, all precipitates including T 1 (Al 2 CuLi), S (Al 2 CuMg), θ′ (Al 2 Cu), δ′, β′ and the cubic phase have appeared, and the formation of T 1 and S results in a rapid increase in hardness. With prolonging of aging time, the apparent coarsening of T 1 and S results in a decline in hardness. - Highlights: •The aging behavior of an in-situ TiB 2 /Al-Cu-Li-x composite was studied. •A cubic phase suspected to be σ (Al 5 Cu 6 Mg 2 ) or its variant was precipitated. •The hardness change was dominated by the evolution of T 1 (Al 2 CuLi) and S (Al 2 CuMg).

Effects of carbon source and carbon content on electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C prepared by one-step solid-state reaction

Energy Technology Data Exchange (ETDEWEB)

Hu Xuebu [College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, Sichuan 610066 (China); Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Lin Ziji [China National Quality Supervision and Inspection Center for Alcoholic Beverage Products and Processed Food, Luzhou, Sichuan 646100 (China); Yang Kerun [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China); Hua, Yongjian [China Aviation Lithium Battery Co. Ltd., Luoyang, Henan 471009 (China); Deng Zhenghua, E-mail: zhdeng@cioc.ac.cn [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, Sichuan 610041 (China)

2011-05-30

Highlights: > A simple route to prepare the Li{sub 4}Ti{sub 5}O{sub 12}/C by one-step solid-state reaction. > Carbon source and carbon content are two important factors on the electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C. > As-prepared Li{sub 4}Ti{sub 5}O{sub 12}/C under optimized conditions shows excellent electrochemical performances. - Abstract: Li{sub 4}Ti{sub 5}O{sub 12}/C composites were synthesized by one-step solid-state reaction method using four commonly used organic compounds or organic polymers as carbon source, i.e., polyacrylate acid (PAA), citric acid (CA), maleic acid (MA) and polyvinyl alcohol (PVA). The physical characteristics of Li{sub 4}Ti{sub 5}O{sub 12}/C composites were investigated by X-ray diffraction, electron microscopy, Raman spectroscopy, particle size distribution and thermogravimetry-derivative thermogravimetry techniques. Their electrochemical properties were characterized by cyclic voltammograms, electrochemical impedance spectra, constant current charge-discharge and rate charge-discharge. These analyses indicated that the carbon source and carbon content have a great effect on the physical and electrochemical performances of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. An ideal carbon source and appropriate carbon content effectively improved the electrical contact between the Li{sub 4}Ti{sub 5}O{sub 12} particles, which enhanced the discharge capacity and rate capability of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. PAA was the best carbon source for the synthesis of Li{sub 4}Ti{sub 5}O{sub 12}/C composites. When the carbon content was 3.49 wt.% (LiOH.H{sub 2}O/PAA molar ratio of 1), as-prepared Li{sub 4}Ti{sub 5}O{sub 12}/C showed the maximum discharge capacity. At 0.2 C, initial capacity of the optimized sample was 168.6 mAh g{sup -1} with capacity loss of 2.8% after 50 cycles. At 8 and 10 C, it showed discharge capacities of 143.5 and 132.7 mAh g{sup -1}, with capacity loss of 8.7 and 9.9% after 50 cycles

Fabrication of TiNb{sub 2}O{sub 7} thin film electrodes for Li-ion micro-batteries by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Daramalla, V. [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India); Penki, Tirupathi Rao; Munichandraiah, N. [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengalore 560012 (India); Krupanidhi, S.B., E-mail: sbk@mrc.iisc.ernet.in [Materials Research Centre, Indian Institute of Science, Bengalore 560012 (India)

2016-11-15

Graphical abstract: The TiNb{sub 2}O{sub 7} thin film electrodes as anode material in Li-ion rechargeable micro-batteries are successfully demonstrated. The pulsed laser deposited TiNb{sub 2}O{sub 7} thin film electrode delivers high discharge specific capacity of 143 μAh μm{sup −1} cm{sup −2} at 50 μA cm{sup −2} current density, with 92% coulombic efficiency. The thin films are very stable in crystal structure, with good fast reversible reaction at average Li-insertion voltage 1.65 V. - Highlights: • TiNb{sub 2}O{sub 7} thin films fabricated by pulsed laser deposition. • TiNb{sub 2}O{sub 7} as anode thin films demonstrated successfully. • High discharge specific capacity with 92% coulombic efficiency. • Excellent crystal stability and good reversible reaction. - Abstract: Pulsed laser deposited TiNb{sub 2}O{sub 7} thin films are demonstrated as anode materials in rechargeable Li-ion micro-batteries. The monoclinic and chemically pure TiNb{sub 2}O{sub 7} films in different morphologies were successfully deposited at 750 °C. The single phase formation was confirmed by grazing incident X-ray diffraction, micro-Raman spectroscopy, high resolution transmission electron microscopy, field emission scanning electron microscopy and X-ray photoelectron spectroscopy. The oxygen partial pressure during the deposition significantly influenced the properties of TiNb{sub 2}O{sub 7} films. The TiNb{sub 2}O{sub 7} thin films exhibited excellent stability with fast kinetics reversible reaction. The TiNb{sub 2}O{sub 7} films showed initial discharge specific capacity of 176, 143 μAh μm{sup −1} cm{sup −2} at 30, 50 μA cm{sup −2} current densities respectively with 92% coulombic efficiency in a non-aqueous electrolyte consisting of Li{sup +} ions. The high discharge specific capacity of TiNb{sub 2}O{sub 7} thin films may be attributed to nanometer grain size with high roughness which offers high surface area for Li-diffusion during charge and discharge

New process of preparation, X-ray characterisation, structure and vibrational studies of a solid solution LiTiOAs 1-xP xO 4 (0⩽ x⩽1)

Science.gov (United States)

Chakir, M.; El Jazouli, A.; Chaminade, J. P.; Bouree, F.; de Waal, D.

2006-01-01

LiTiOAs 1-xP xO 4 (0⩽ x⩽1) compounds have been prepared using solutions of Li, Ti, As and P elements as starting products. Selected compositions have been investigated by powder X-ray or neutrons diffraction analysis, Raman and infrared spectroscopy. The structure of LiTiOAs 1-xP xO 4 ( x=0, 0.5 and 1) samples determined by Rietveld analysis is orthorhombic with Pnma space group. It is formed by a 3D network of TiO 6 octahedra and XO 4 ( X=As 1-xP x) tetrahedra where octahedral cavities are occupied by lithium atoms. TiO 6 octahedra are linked together by corners and form infinite chains along a-axis. Ti atoms are displaced from the centre of octahedral units in alternating short (1.700-1.709 Å) and long (2.301-2.275 Å) Ti-O bonds. Raman and infrared studies confirm the existence of Ti-O-Ti chains. Thermal stability of LiTiOAsO 4 has been reported.

Candice Lin: paisaje, territorio y fronteras (Candice Lin: Landscape, Territory and Boundaries

Directory of Open Access Journals (Sweden)

Gabriel Baltodano Román

2017-11-01

Full Text Available Se analizan los contenidos ideológicos de la acuarela «Nacimiento de una nación» (2008, de Candice Lin. A partir de nociones como territorio, tropo caníbal, tipo botánico tropical y pensamiento fronterizo, se plantea una interpretación de esa paisajística pictórica, en que la artista-activista reflexiona sobre el régimen de representación visual. Mediante diversos procedimientos formales, Lin pone en entredicho preceptos centrales de la mentalidad colonialista, que contrapone a las concepciones indigenistas. Abstract An analysis is provided of the ideological contents of the watercolor “Birth of a Nation” (2008, by Candice Lin. This interpretation of this pictorial landscape is based on notions such as territory, cannibal tropes, tropical botanical types and border thinking. The artist activist reflects here on the regime of visual representation. Using different formal procedures, Lin questions central precepts of the colonialist mentality, in contrast with indigenous conceptions.

Li_4Ti_5O_1_2/Ketjen Black with open conductive frameworks for high-performance lithium-ion batteries

International Nuclear Information System (INIS)

Zhang, Yang; Dong, Hui; Zhang, Huang; Liu, Yijun; Ji, Mandi; Xu, Yunlong; Wang, Qingqing; Luo, Lei

2016-01-01

Graphical abstract: The Li_4Ti_5O_1_2/Ketjen Black composites are synthesized via a simple hydrothermal method. As an anode for lithium ion battery, the composite exhibits ultrahigh capacity and excellent low temperature performance. - Highlights: • Mesoporous LTO/KB composites were synthesized via hydrothermal method. • KB is used as carbon template and conductive additive. • The LTO/KB electrode without carbon black was fabricated. • This as-prepared electrode shows excellent rate capacity performance. • LTO/KB composite exhibits ultrahigh cycle performance at low temperature. - Abstract: The Li_4Ti_5O_1_2/Ketjen Black composites are synthesized via a simple hydrothermal method. The materials are characterized by XRD, SEM, HR-TEM, EDS, galvanostatic charge/discharge test, CV and EIS. The results indicate that Li_4Ti_5O_1_2 (LTO) particles grow both in the pores and on the surface of mesoporous Ketjen Black (KB) forming open conductive frameworks and the Ketjen Black works as host forthe growth of Li_4Ti_5O_1_2 primary nanoparticles. The LTO/KB electrode is fabricated without extra carbon black conductive agents and exhibits excellent electrochemical performances, especially at low temperature. The improved performances can be attributed to the presence of mesoporous Ketjen Black conductive templates with high electronic conductivity and formed 3D frameworks beneficial to the lithium ion diffusion.

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O3 lead-free ceramics

International Nuclear Information System (INIS)

Chen, Xiaoming; Ruan, Xuezheng; Zhao, Kunyun; He, Xueqing; Zeng, Jiangtao; Li, Yongsheng; Zheng, Liaoying; Park, Chul Hong; Li, Guorong

2015-01-01

Highlights: • Li-doped Ba 0.85 Ca 0.15 Ti 0.9 Zr 0.1 O 3 (BCZT) lead-free piezoceramics were prepared by the two-step synthesis and solid-state reaction method. • Their sintering temperature decreases from about 1540 °C down to about 1400 °C. • With the proper addition of Li, the densities and grain sizes of ceramics increase. • The ceramics not only have the characteristics of hard piezoceramics but also possesses the features of soft piezoceramics at low sintering temperature. - Abstract: Li-doped Ba 0.85 Ca 0.15 Ti 0.9 Zr 0.1 O 3 (BCZT) lead-free piezoelectric ceramics were prepared by the two-step synthesis and the solid-state reaction method. The density and grain size of ceramics sufficiently increases by Li-doped sintering aid, and their sintering temperature decreases from about 1540 °C down to about 1400 °C. X-ray diffraction reveals that the phase structure of Li-doped BCTZ ceramics is changed with the sintering temperature, which is consistent with their phase transition observed by the temperature-dependent dielectric curves. The well-poled Li-doped BCZT ceramics show a high piezoelectric constant d 33 (512 pC/N) and a planar electromechanical coupling factor k p (0.49), which have the characteristics of soft Pb(Zr,Ti)O 3 (PZT) piezoceramic, on the other hand, the mechanical quality factor Q m is about 190, which possesses the features of hard PZT piezoceramics. The enhanced properties of the Li-doped BCZT are explained by the combination of Li-doped effect and sintering effect on the microstructure and the phase transition around room temperature

Pseudocapacitive Behaviors of Li2FeTiO4/C Hybrid Porous Nanotubes for Novel Lithium-Ion Battery Anodes with Superior Performances.

Science.gov (United States)

Tang, Yakun; Liu, Lang; Zhao, Hongyang; Zhang, Yue; Kong, Ling Bing; Gao, Shasha; Li, Xiaohui; Wang, Lei; Jia, Dianzeng

2018-06-20

Hybrid nanotubes of cation disordered rock salt structured Li 2 FeTiO 4 nanoparticles embedded in porous CNTs were developed. Such unique hybrids with continuous 3D electron transportation paths and isolated small particles have been shown to be an ideal architecture that brought out enhanced electrochemical performances. Meanwhile, they exhibited improved extrinsic capacitive characteristics. In addition, we demonstrate a successful example to use cathode active material as anode for lithium-ion batteries (LIBs). More importantly, our hybrids had much superior electrochemical performances than most of the reported Li 4 Ti 5 O 12 -based nanocomposites. Therefore, it is concluded that Li 2 FeTiO 4 can be a prospective anode material for LIBs.

The modification of some properties of Al-2%Mg alloy by Ti &Li alloying elements

Directory of Open Access Journals (Sweden)

Talib Abdulameer Jasim

2017-11-01

Full Text Available Aluminium-Magnisium alloys are light, high strength with resistance to corrosion and good weldability. When the content of magnesium  exceeds 3% there is a tendency to stress corrosion . This work is an attempt is to prepare low density alloy with up to approximately 2.54 g / cm3 by adding different contents of Ti, and lithium to aluminum-2%Magnisium alloy. The lithium is added in two aspects, lithium chloride and pure metal. The casting performed using conventional casting method. Moreover, solution heat treatment (SHT at 520 ºC for 4 hrs, quenching in cold water, and aging at 50ºC for 4 days were done to get better mechanical properties of all samples. Microstructure was inspected by light optical microscope before and after SHT. Alloy3 which contains 1.5%Ti was tested by SEM and EDS spectrometer to exhibit the shape and micro chemical analysis of Al3Ti phase. Hardness, ultimate tensile strength, and modulus of elasticity were tested for all alloys. The results indicated that Al3Ti phase precipitates in alloys contain 0.5%T, 1%Ti, And 1.5%Ti.  The phases Al3Li as well as Al3Ti were precipitated in alloy4 which contains 2%Ti, and 2.24%Li. Mechanical properties test results also showed that the alloy4 has achieved good results, the modulus of elasticity chanced from 310.65GPa before SHT to 521.672GPa, after SHT and aging, the ultimate tensile strength was changed from 365MPa before SHT to 469MPa, after SHT and aging,  and hardness was increased from 128 to 220HV.

Fabrication of Li{sub 2}TiO{sub 3} pebbles by a freeze drying process

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang-Jin, E-mail: lee@mokpo.ac.kr [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of); Park, Yi-Hyun [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Yu, Min-Woo [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of)

2013-11-15

Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by using a freeze drying process. The Li{sub 2}TiO{sub 3} slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li{sub 2}TiO{sub 3} pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined.

Analysis list: lin-13 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available lin-13 Embryo,Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/...lin-13.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/lin-13.5.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/target/lin-13.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/lin-13.Embryo....tsv,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/lin-13.Larvae.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

In vitro expansion of Lin{sup +} and Lin{sup −} mononuclear cells from human peripheral blood

Energy Technology Data Exchange (ETDEWEB)

Norhaiza, H. Siti; Zarina, Z. A. Intan; Hisham, Z. A. Shahrul [School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Selangor (Malaysia); Rohaya, M. A. W. [Department of Orthodontics, Faculty of Dentistry, Universiti Kebangsaan Malaysia, 50300, Kuala Lumpur (Malaysia)

2013-11-27

Haematopoietic stem cells (HSCs) are used in the therapy of blood disorders due to the ability of these cells to reconstitute haematopoietic lineage cells when transplanted into myeloablative recipients. However, substantial number of cells is required in order for the reconstitution to take place. Since HSCs present in low frequency, larger number of donor is required to accommodate the demand of transplantable HSCs. Therefore, in vitro expansion of HSCs will have profound impact on clinical purposes. The aim of this study was to expand lineage negative (Lin{sup −}) stem cells from human peripheral blood. Total peripheral blood mononuclear cells (PBMNCs) were fractionated from human blood by density gradient centrifugation. Subsequently, PBMNCs were subjected to magnetic assisted cell sorter (MACS) which depletes lineage positive (Lin{sup +}) mononuclear cells expressing lineage positive markers such as CD2, CD3, CD11b, CD14, CD15, CD16, CD19, CD56, CD123, and CD235a to obtained Lin{sup −} cell population. The ability of Lin{sup +} and Lin{sup −} to survive in vitro was explored by culturing both cell populations in complete medium consisting of Alpha-Minimal Essential Medium (AMEM) +10% (v/v) Newborn Calf Serum (NBCS)+ 2% (v/v) pen/strep. In another experiment, Lin{sup +} and Lin{sup −} were cultured with complete medium supplemented with 10ng/mL of the following growth factors: stem cell factor (SCF), interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF), 2IU/mL of Erythropoietin (Epo) and 20ng/mL of IL-6. Three samples were monitored in static culture for 22 days. The expansion potential was assessed by the number of total viable cells, counted by trypan blue exclusion assay. It was found that Lin{sup +} mononuclear cells were not able to survive either in normal proliferation medium or proliferation medium supplemented with cytokines. Similarly, Lin{sup −} stem cells were not able to survive in proliferation medium however

Characterization of the personal thermoluminescent dosemeter of LiF: Mg, Ti + Ptfe

International Nuclear Information System (INIS)

Azorin N, J.; Gutierrez C, A.; Gonzalez M, P.

1991-01-01

The objective of this work is to characterize the thermoluminescent dosemeters taken place in the laboratory in form of pellets of LiF: Mg, Ti + Ptfe like personal dosemeters, subjecting them to the operation tests proposed by the international standards and comparing them with the TLD-100, the Tl dosemeter more used at the moment for personal dosimetry

Selection and Performance-Degradation Modeling of LiMO2/Li4Ti5O12 and LiFePO4/C Battery Cells as Suitable Energy Storage Systems for Grid Integration With Wind Power Plants

DEFF Research Database (Denmark)

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

2014-01-01

Advances in the development of energy storage technologies are making them attractive for grid integration together with wind power plants. Thus, the new system, the virtual power plant, is able to emulate the characteristics of today’s conventional power plants. However, at present, energy stora......-degradation models were developed for the two most suitable Li–ion chemistries for the primary frequency regulation service: LiMO2 /Li4Ti5O12 and LiFePO4/C....

Pressure-composition isotherms and thermodynamic properties of TiF3-enhanced Na2LiAlH6

International Nuclear Information System (INIS)

Fossdal, A.; Brinks, H.W.; Fonnelop, J.E.; Hauback, B.C.

2005-01-01

The mixed alanate Na 2 LiAlH 6 was prepared by ball-milling and subsequent heat-treatment under H 2 pressure. After the synthesis, 2 mol% TiF 3 was added by ball-milling. Pressure-composition isotherms were measured for the Ti-enhanced material in the temperature range of 170-250 deg C. A van't Hoff plot was constructed using the equilibrium desorption plateau pressures. From this plot, a dissociation enthalpy of 56.4 ± 0.4 kJ/mol H 2 and a corresponding entropy of 137.9 ± 0.7 J/K mol H 2 was found for Na 2 LiAlH 6

Specific heat measurements of TiB2 and 6LiF from 0.5 to 30 K

International Nuclear Information System (INIS)

Lang, Brian E.; Donaldson, Marcus H.; Woodfield, Brian F.; Burger, Arnold; Roy, Utupal N.; Lamberti, Vincent; Bell, Zane W.

2005-01-01

The specific heats of TiB 2 and 6 LiF have been measured from 0.5 to 30 K as part of a larger project in the construction of a neutron spectrometer. For this application, the measured specific heats were used to extrapolate the specific heats down to 0.1 K with lattice, electronic, and Schottky equations for the respective samples. The resultant specific heat values at 0.1 K for TiB 2 and 6 LiF are 4.08 x 10 -4 ± 0.27 x 10 -4 J/K/mol and 9.19 x 10 -9 ± 0.15 x 10 -9 J/K/mol, respectively

Phase-pure Nanocrystalline Li4Ti5O12 for Lithium ion Battery

Czech Academy of Sciences Publication Activity Database

Kalbáč, Martin; Zukalová, Markéta; Kavan, Ladislav

2003-01-01

Roč. 8, č. 1 (2003), s. 2-6 ISSN 1432-8488 R&D Projects: GA MŠk OC D14.10 Institutional research plan: CEZ:AV0Z4040901 Keywords : phase purity * Li4Ti5O12 * nanocrystalline materials Subject RIV: CG - Electrochemistry Impact factor: 1.195, year: 2003

Electrochemical performance of Li-rich oxide composite material coated with Li{sub 0.75}La{sub 0.42}TiO{sub 3} ionic conductor

Energy Technology Data Exchange (ETDEWEB)

Yang, Chun-Chen, E-mail: ccyang@mail.mcut.edu.tw [Battery Research Center of Green Energy, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Liao, Pin-Ci [Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Wu, Yi-Shiuan [Battery Research Center of Green Energy, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan, ROC (China); Lue, Shingjiang Jessie [Department of Chemical and Materials Engineering, and Green Technology Research Center, Chang Gung University, Kwei-shan, Tao-yuan 333, Taiwan , ROC (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Tao-yuan 333, Taiwan, ROC (China); Department of Safety, Health and Environmental Engineering, Ming Chi University of Technology, NewTaipei City 243, Taiwan, ROC (China)

2017-03-31

Graphical abstract: Schematic diagram for Li-rich oxide (Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}) coated with Li{sub 0.75}La{sub 0.42}TiO{sub 3} (LLTO) solid ionic conductor. - Highlights: • Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}/C composite material was prepared by one-pot solid-state method. • 1D a-MnO{sub 2} nanowires and microsphere hollow b-Ni(OH){sub 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{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2}) composite materials were prepared via two-step ball-mill and spray dry methods by using LiOH, α-MnO{sub 2}, β-Ni(OH){sub 2} raw materials. Two raw materials of α-MnO{sub 2} nanowires and microsphere β-Ni(OH){sub 2} were synthesized by a hydrothermal process. In addition, Li{sub 0.75}La{sub 0.42}TiO3 (LLTO) fast ionic conductor was coated on SP-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2} composite via a sol–gel method. The properties of the LLTO-coated SP-Li{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 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{sub 1.2}Ni{sub 0.2}Mn{sub 0.60}O{sub 2} composites were 256, 250, 231, 200, 158, and 114 mAh g{sup {sub −}{sub 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{sup −1} in the first cycle at 0.1C. After 30 cycles, the discharge capacity of 244 mAh g{sup −1} was obtained, which showed the capacity retention of 95.4%.

Nitrogen-tuned bonding mechanism of Li and Ti adatom embedded graphene

International Nuclear Information System (INIS)

Lee, Sangho; Chung, Yong-Chae

2013-01-01

The effects of nitrogen defects on the bonding mechanism and resultant binding energy between the metal and graphene layer were investigated using density functional theory (DFT) calculations. For the graphitic N-doped graphene, Li adatom exhibited ionic bonding character, while Ti adatom showed features of covalent bonding similar to that of pristine graphene. However, in the cases of pyridinic and pyrrolic structures, partially covalent bonding characteristic occurred around N atoms in the process of binding with metals, and this particular bond formation enhanced the bond strength of metal on the graphene layer as much as it exceeded the cohesive energy of the metal bulk. Thus, Li and Ti metals are expected to be dispersed with atomic accuracy on the pyridinic and pyrrolic N-doped graphene layers. These results demonstrate that the bonding mechanism of metal–graphene complex can change according to the type of N defect, and this also affects the binding results. - Graphical abstract: Display Omitted - Highlights: • Nitrogen defects changed the bonding mechanism between metal and graphene. • Bonding character and binding results were investigated using DFT calculations. • Covalent bonding character occurred around pyridinic and pyrrolic N-doped graphene. • Pyridinic and pyrrolic N atoms are effective for metal dispersion on the graphene

Li4Ti5O12 on graphene for high rate lithium ion batteries

CSIR Research Space (South Africa)

Wen, L

2016-11-01

Full Text Available Spinel Li(sub4)Ti(sub5)O(sub12) has been considered as a promising anode material to substitute graphite in lithium ion batteries (LIBs) for large scale electrical energy storage due to its high safety and long cycling stability. However...

Preparation of Li4Ti5O12 electrode thin films by a mist CVD process with aqueous precursor solution

Directory of Open Access Journals (Sweden)

Kiyoharu Tadanaga

2015-03-01

Full Text Available Spinel Li4Ti5O12 thin films were prepared by a mist CVD process, using an aqueous solution of lithium nitrate and a water-soluble titanium lactate complex as the source of Li and Ti, respectively. In this process, mist particles ultrasonically atomized from a source aqueous solution were transferred by nitrogen gas to a heating substrate to prepare thin films. Scanning electron microscopy observation showed that thin films obtained by this process were dense and smooth, and thin films with a thickness of about 500 nm were obtained. In the X-ray diffraction analysis, formation of Li4Ti5O12 spinel phase was confirmed in the obtained thin film sintered at 700 °C for 4 h. The cell with the thin films as an electrode exhibited a capacity of about 110 mAh g−1, and the cell showed good cycling performance during 10 cycles.

Thermoluminescence of LiF: Mg, Ti between 77 and 315 K

International Nuclear Information System (INIS)

Rosa, L.A.R. da.

1989-01-01

A special thermoluminescent system was developed. It is able to operate right from liquid nitrogen temperature and also permits the determination of the sample thermoluminescent emission spectrum. Using this system, the thermoluminescence displayed by 77 K irradiated LiF:Mg,Ti (TLD-100), from the irradiation temperature to 315 K, was studied. In this temperature range seven glow peaks, at 139, 153, 194, 240, 260, 283 and 300 K, were determined. (author)

The 15th Internatonal Conference Quality in Resarch (Qir) 2017 Preparation and Ionic Conductivity of Li3.9Ca0.1Ti5O12 Using Waste Chicken Eggshells as ca Source for Anode Material of Lithium-Ion Batteries

Science.gov (United States)

Subhan, Achmad; Setiawan, Dedy; Ahmiatri Saptari, Sitti

2018-03-01

Li3.9Ca0.1Ti5O12 has been synthesized as anode material for lithium-ion batteries parallel with Li4Ti5O12 anode material using solid state reaction method in an air atmosphere. LiOH.H2O, TiO2, and waste chicken eggshells in the form of CaCO3 were chosen as sources of Li, Ti, and Ca respectively and prepared using stoichiometric. The phase structure, morphology, and electrochemical impedance of as-prepared samples were characterized using XRD, SEM, and EIS. The XRD characterization revealed that in Li3.9Ca0.1Ti5O12 sample, all amount of dopant had entered the lattice structure of Li4Ti5O12. The EDX image also detect the existence of Ca in the structure of Li3.9Ca0.1Ti5O12. The EIS characterization revealed that the Li3.9Ca0.1Ti5O12 sample had lower electrochemical impedance compared to the Li4Ti5O12 sample. The diffusion coefficient were obtained by Faraday’s method, and exhibited that the Li3.9Ca0.1Ti5O12 sample (1.46986 × 10-12 cm2/s) had higher ionic conductivity than the Li4Ti5O12 sample (4.40995 × 10-16 cm2/s). According to the cycle performance test, the Li3.9Ca0.1Ti5O12 sample also had higher charge-discharge capacity and stability compared to the Li4Ti5O12 sample.

Shuttle inhibition by chemical adsorption of lithium polysulfides in B and N co-doped graphene for Li-S batteries.

Science.gov (United States)

Li, Fen; Su, Yan; Zhao, Jijun

2016-09-14

The advance of lithium sulfur batteries is now greatly restricted by the fast capacity fading induced by shuttle effect. Using first-principles calculations, various vacancies, N doping, and B,N co-doping in graphene sheets have been systematically explored for lithium polysufides entrapped in Li-S batteries. The LiS, LiC, LiN and SB bonds and Hirshfeld charges in the Li 2 S 6 adsorbed defective graphene systems have been analyzed to understand the intrinsic mechanism of retaining lithium polysulfides in these systems. Total and local densities of states analyses elucidate the strongest adsorption sites among the N and B-N co-doped graphene systems. The overall electrochemical performance of Li-S batteries varies with the types of defects in graphene. Among the defective graphene systems, only the reconstructed pyrrole-like vacancy is effective for retaining lithium polysulfides. N doping induces a strong LiN interaction in the defective graphene systems, in which the pyrrolic N rather than the pyridinic N plays a dominant role in trapping of lithium polysulfides. The shuttle effect can be further depressed via pyrrolic B,N co-doped defective graphene materials, especially the G-B-N-hex system with extremely strong adsorption of lithium polysulfides (4-5 eV), and simultaneous contribution from the strong LiN and SB interactions.

Aging behavior of an in-situ TiB{sub 2}/Al-Cu-Li-x matrix composite

Energy Technology Data Exchange (ETDEWEB)

Shen, Yanwei; Hong, Tianran; Geng, Jiwei; Han, Gaoyang; Chen, Dong; Li, Xianfeng, E-mail: brucelee75cn@sjtu.edu.cn; Wang, Haowei

2017-02-15

Transmission electron microscopy, differential scanning calorimetry and hardness tests have been performed on an in-situ TiB{sub 2}/Al-3.3Cu-1.0Li-0.60Mg-0.40Ag-0.14Zr-0.13Si composite to study its aging behavior at 175 °C. A cubic phase suspected to be the σ (Al{sub 5}Cu{sub 6}Mg{sub 2}) phase or its variant is precipitated at all aging stages studied, and this phase is not typically observed in the Al-Cu-Li alloys. The primary hardening (aging for 3 h) phases consist of δ′ (Al{sub 3}Li), β′ (Al{sub 3}Zr) and the cubic phase. After aging for 18 h, all precipitates including T{sub 1} (Al{sub 2}CuLi), S (Al{sub 2}CuMg), θ′ (Al{sub 2}Cu), δ′, β′ and the cubic phase have appeared, and the formation of T{sub 1} and S results in a rapid increase in hardness. With prolonging of aging time, the apparent coarsening of T{sub 1} and S results in a decline in hardness. - Highlights: •The aging behavior of an in-situ TiB{sub 2}/Al-Cu-Li-x composite was studied. •A cubic phase suspected to be σ (Al{sub 5}Cu{sub 6}Mg{sub 2}) or its variant was precipitated. •The hardness change was dominated by the evolution of T{sub 1} (Al{sub 2}CuLi) and S (Al{sub 2}CuMg).

Analysis list: lin-35 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available lin-35 Adult,Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/l...in-35.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/lin-35.5.tsv http://dbarchive.bioscienced...bc.jp/kyushu-u/ce10/target/lin-35.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/lin-35.Adult.t...sv,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/lin-35.Larvae.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/ce10/colo/Adult.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

Low sintering temperature and high piezoelectric properties of Li-doped (Ba,Ca)(Ti,Zr)O{sub 3} lead-free ceramics

Energy Technology Data Exchange (ETDEWEB)

Chen, Xiaoming [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Ruan, Xuezheng; Zhao, Kunyun [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); He, Xueqing [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Zeng, Jiangtao, E-mail: zjt@mail.sic.ac.cn [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Li, Yongsheng [School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zheng, Liaoying [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Park, Chul Hong [Department of Physics Education, Pusan National University, Pusan 609735 (Korea, Republic of); Li, Guorong [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China)

2015-05-25

Highlights: • Li-doped Ba{sub 0.85}Ca{sub 0.15}Ti{sub 0.9}Zr{sub 0.1}O{sub 3} (BCZT) lead-free piezoceramics were prepared by the two-step synthesis and solid-state reaction method. • Their sintering temperature decreases from about 1540 °C down to about 1400 °C. • With the proper addition of Li, the densities and grain sizes of ceramics increase. • The ceramics not only have the characteristics of hard piezoceramics but also possesses the features of soft piezoceramics at low sintering temperature. - Abstract: Li-doped Ba{sub 0.85}Ca{sub 0.15}Ti{sub 0.9}Zr{sub 0.1}O{sub 3} (BCZT) lead-free piezoelectric ceramics were prepared by the two-step synthesis and the solid-state reaction method. The density and grain size of ceramics sufficiently increases by Li-doped sintering aid, and their sintering temperature decreases from about 1540 °C down to about 1400 °C. X-ray diffraction reveals that the phase structure of Li-doped BCTZ ceramics is changed with the sintering temperature, which is consistent with their phase transition observed by the temperature-dependent dielectric curves. The well-poled Li-doped BCZT ceramics show a high piezoelectric constant d{sub 33} (512 pC/N) and a planar electromechanical coupling factor k{sub p} (0.49), which have the characteristics of soft Pb(Zr,Ti)O{sub 3} (PZT) piezoceramic, on the other hand, the mechanical quality factor Q{sub m} is about 190, which possesses the features of hard PZT piezoceramics. The enhanced properties of the Li-doped BCZT are explained by the combination of Li-doped effect and sintering effect on the microstructure and the phase transition around room temperature.

Enhanced Power Conversion Efficiency of Perovskite Solar Cells with an Up-Conversion Material of Er3+-Yb3+-Li+ Tri-doped TiO2.

Science.gov (United States)

Zhang, Zhenlong; Qin, Jianqiang; Shi, Wenjia; Liu, Yanyan; Zhang, Yan; Liu, Yuefeng; Gao, Huiping; Mao, Yanli

2018-05-11

In this paper, Er 3+ -Yb 3+ -Li + tri-doped TiO 2 (UC-TiO 2 ) was prepared by an addition of Li + to Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 presented an enhanced up-conversion emission compared with Er 3+ -Yb 3+ co-doped TiO 2 . The UC-TiO 2 was applied to the perovskite solar cells. The power conversion efficiency (PCE) of the solar cells without UC-TiO 2 was 14.0%, while the PCE of the solar cells with UC-TiO 2 was increased to 16.5%, which presented an increase of 19%. The results suggested that UC-TiO 2 is an effective up-conversion material. And this study provided a route to expand the spectral absorption of perovskite solar cells from visible light to near-infrared using up-conversion materials.

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

Directory of Open Access Journals (Sweden)

Chunhui Chen

2015-08-01

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

CHARACTERISTICS OF LITHIUM LANTHANUM TITANATE THIN FILMS MADE BY ELECTRON BEAM EVAPORATION FROM NANOSTRUCTURED La0.67-xLi 3xTiO3 TARGET

Directory of Open Access Journals (Sweden)

Nguyen Nang Dinh

2017-11-01

Full Text Available Bulk nanostructured perovskites of La0.67-xLi3xTiO3 (LLTO were prepared by using thermally ball-grinding from compounds of La2O3, Li2CO3 and TiO2. From XRD analysis, it was found that LTTO materials were crystallized with nano-size grains of an average size of 30 nm. The bulk ionic conductivity was found strongly dependent on the Li+ composition, the samples with x = 0.11 (corresponding to a La0.56Li0.33TiO3 compound have the best ionic conductivity, which is ca. 3.2 x 10-3 S/cm at room temperature. The LLTO amorphous films were made by electron beam deposition. At room temperature the smooth films have ionic conductivity of 3.5 x 10-5  S/cm and transmittance of 80%. The optical bandgap of the films was found to be of 2.3 eV. The results have shown that the perovskite La0.56Li0.33TiO3  thin films can be used for a transparent solid electrolyte in ionic battery and in all-solid-state electrochromic devices, in particular.

Spray drying of spherical Li{sub 4}Ti{sub 5}O{sub 12}/C powders using polyvinyl pyrrolidone as binder and carbon source

Energy Technology Data Exchange (ETDEWEB)

Liu, Wei [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China); Shanghai Nanotechnology Promotion Center, Shanghai 200237 (China); Wang, Qian; Cao, Chunhui [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China); Han, Xuewu [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Zhang, Jian, E-mail: zjskycn@163.com [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xie, Xiaohua, E-mail: xiaohuaxie@126.com [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Xia, Baojia [Research Center for New Energy Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); University of Chinese Academy of Sciences, Beijing 110049 (China)

2015-02-05

Highlights: • The spherical Li{sub 4}Ti{sub 5}O{sub 12}/C granules were prepared by spray drying. • Polyvinyl pyrrolidone (PVP) was used as binder and carbon source. • Tap density and spherical structure increase with the increase of PVP content. • Li{sub 4}Ti{sub 5}O{sub 12}/C granules exhibits better rate capability and excellent cyclability. - Abstract: Polyvinyl pyrrolidone (PVP) was used as binder and carbon source to synthesize stable and spherical Li{sub 4}Ti{sub 5}O{sub 12}/C granules by spray drying. The effects of PVP content and atmospheres on the properties of Li{sub 4}Ti{sub 5}O{sub 12} were investigated. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and electrochemical tests, respectively. The results indicate that the average particle size, tap density and degree of spherical structure increase accordingly to the increase of PVP content. However, the large secondary particle would deteriorate the rate capacity at high current density. The carbon coating could significantly improve the rate capacity, which is attributed to the smaller primary particle and higher electrical conductivity.

Strong red-emission of Eu{sup 3+}:Li{sub 4}Ti{sub 5}O{sub 12} powders for phosphor applications

Energy Technology Data Exchange (ETDEWEB)

Yang, Yan [Kazuo Inamori School of Engineering, New York State College of Ceramics, Alfred University, Alfred, NY 14802 (United States); Jiménez, José A. [Department of Chemistry, University of North Florida, Jacksonville, FL 32224 (United States); Wu, Yiquan, E-mail: wuy@alfred.edu [Kazuo Inamori School of Engineering, New York State College of Ceramics, Alfred University, Alfred, NY 14802 (United States)

2016-08-15

The synthesis and photoluminescence properties of trivalent europium doped lithium titanate (Eu{sup 3+}:Li{sub 4}Ti{sub 5}O{sub 12}) with different Eu{sup 3+} concentrations (0.1 mol%, 0.3 mol%, 1.0 mol%, 3.0 mol%) are reported and analyzed as a phosphor. Europium (III) nitrate (Eu(NO{sub 3}){sub 3}) was employed as Eu{sup 3+} source, while lithium acetate dihydrate (CH{sub 3}COOLi·2H{sub 2}O) and titanium n-butoxide (Ti(OC{sub 4}H{sub 9}){sub 4}) were adopted as raw materials to synthesize the host lithium titanate with a Li:Ti stoichiometry of 4.5:1. Phase identification was performed using X-ray diffraction (XRD), and morphology was examined using scanning electron microscopy (SEM). Eu{sup 3+}:Li{sub 4}Ti{sub 5}O{sub 12} powders showed strong red emission at 612 nm, corresponding to the {sup 5}D{sub 0}–{sup 7}F{sub 2} transition, with the strongest excitation peak observed in the blue light region at 464 nm. Decay time analyses revealed relatively short lifetimes accompanying typical exponential decay rates. The effect of Eu{sup 3+} concentration (0.1 mol%, 0.3 mol%, 1.0 mol%, 3.0 mol%) on photoluminescence intensity and decay time was explored, and is reported here. It was determined that the CIE color coordinates (0.66, 0.34) of the doped Li{sub 4}Ti{sub 5}O{sub 12} powders were independent of Eu{sup 3+} concentration, and that the coordinates are very similar to the ideal red chromaticity (0.67, 0.33) designated by the National Television Standard Committee (NTSC) system.

Some dosimetric properties of the LiF:Mg,Ti evaluated by the automatic 6600 thermoluminescent reader

Energy Technology Data Exchange (ETDEWEB)

Ben-Shachar, B; Weinstein, M; German, U [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

1996-12-01

Some dosimetric properties of the new LiF:Mg,Ti TLD cards were checked, when evaluated by the new automatic 6600 TLD reader. The cards were calibrated to a dose of 1.0 mGy by five identical irradiations, and the TL-dose response was measured for a range of 75 - 1100 mGy. A very high accuracy was found for the three kind of chips measured (TLD-100, TLD-700 and TLD-600) and a low minimum measurable dose (MMD) was found, too. There is a good fit between the analytical evaluation and the theoretical calculation of the MMD. The results obtained are much better than those of the LiF:Mg,Ti cards evaluated by the older automatic 2271 reader used in the last two decades (authors).

A high energy and power Li-ion capacitor based on a TiO2 nanobelt array anode and a graphene hydrogel cathode.

Science.gov (United States)

Wang, Huanwen; Guan, Cao; Wang, Xuefeng; Fan, Hong Jin

2015-03-25

A novel hybrid Li-ion capacitor (LIC) with high energy and power densities is constructed by combining an electrochemical double layer capacitor type cathode (graphene hydrogels) with a Li-ion battery type anode (TiO(2) nanobelt arrays). The high power source is provided by the graphene hydrogel cathode, which has a 3D porous network structure and high electrical conductivity, and the counter anode is made of free-standing TiO(2) nanobelt arrays (NBA) grown directly on Ti foil without any ancillary materials. Such a subtle designed hybrid Li-ion capacitor allows rapid electron and ion transport in the non-aqueous electrolyte. Within a voltage range of 0.0-3.8 V, a high energy of 82 Wh kg(-1) is achieved at a power density of 570 W kg(-1). Even at an 8.4 s charge/discharge rate, an energy density as high as 21 Wh kg(-1) can be retained. These results demonstrate that the TiO(2) NBA//graphene hydrogel LIC exhibits higher energy density than supercapacitors and better power density than Li-ion batteries, which makes it a promising electrochemical power source. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

One-step argon/nitrogen binary plasma jet irradiation of Li4Ti5O12 for stable high-rate lithium ion battery anodes

Science.gov (United States)

Lan, Chun-Kai; Chuang, Shang-I.; Bao, Qi; Liao, Yen-Ting; Duh, Jenq-Gong

2015-02-01

Atmospheric pressure Ar/N2 binary plasma jet irradiation has been introduced into the manufacturing process of lithium ions batteries as a facile, green and scalable post-fabrication treatment approach, which enhanced significantly the high-rate anode performance of lithium titanate (Li4Ti5O12). Main emission lines in Ar/N2 plasma measured by optical emission spectroscopy reveal that the dominant excited high-energy species in Ar/N2 plasma are N2*, N2+, N∗ and Ar∗. Sufficient oxygen vacancies have been evidenced by high resolution X-ray photoelectron spectroscopy analysis and Raman spectra. Nitrogen doping has been achieved simultaneously by the surface reaction between pristine Li4Ti5O12 particles and chemically reactive plasma species such as N∗ and N2+. The variety of Li4Ti5O12 particles on the surface of electrodes after different plasma processing time has been examined by grazing incident X-Ray diffraction. Electrochemical impedance spectra (EIS) confirm that the Ar/N2 atmospheric plasma treatment facilitates Li+ ions diffusion and reduces the internal charge-transfer resistance. The as-prepared Li4Ti5O12 anodes exhibit a superior capacity (132 mAh g-1) and excellent stability with almost no capacity decay over 100 cycles under a high C rate (10C).

Surface desorption and bulk diffusion models of tritium release from Li{sub 2}TiO{sub 3} and Li{sub 2}ZrO{sub 3} pebbles

Energy Technology Data Exchange (ETDEWEB)

Avila, R.E., E-mail: ravila@cchen.c [Departamento de Materiales Nucleares, Comision Chilena de Energia Nuclear, Cas. 188-D, Santiago (Chile); Pena, L.A.; Jimenez, J.C. [Departamento de Produccion y Servicios, Comision Chilena de Energia Nuclear, Cas. 188-D, Santiago (Chile)

2010-10-30

The release of tritium from Li{sub 2}TiO{sub 3} and Li{sub 2}ZrO{sub 3} pebbles, in batch experiments, is studied by means of temperature programmed desorption. Data reduction focuses on the analysis of the non-oxidized and oxidized tritium components in terms of release limited by diffusion from the bulk of ceramic grains, or by first or second order surface desorption. By analytical and numerical methods the in-furnace tritium release is deconvoluted from the ionization chamber transfer functions, for which a semi-empirical form is established. The release from Li{sub 2}TiO{sub 3} follows second order desorption kinetics, requiring a temperature for a residence time of 1 day (T{sub 1dRes}) of 620 K, and 603 K, of the non-oxidized, and the oxidized components, respectively. The release from Li{sub 2}ZrO{sub 3} appears as limited by either diffusion from the bulk of the ceramic grains, or by first order surface desorption, the first possibility being the more probable. The respective values of T{sub 1dRes} for the non-oxidized component are 661 K, according to the first order surface desorption model, and 735 K within the bulk diffusion limited model.

Ionic conductivity of the lithium titanium phosphate (Li/sub 1+x/M/sub x/Ti/sub 2-x/(PO/sub 4/)/sub 3/, M=Al, Sc, Y, and La) systems

International Nuclear Information System (INIS)

Aono, H.; Sugimoto, E.; Sadaaka, Y.; Imanaka, N.; Adachi, G.Y.

1989-01-01

High lithium ionic conductivity was obtained in Li/sub 1+X/M/sub X/Ti/sub 2-X/(PO/sub 4/)/sub 3/ (M=Al, Sc, Y, and La) systems. Lithium titanium phosphate, LiTi/sub 2/(PO/sub 4/)/sub 3/, is composed of both TiO/sub 6/ octahedra and PO/sub 4/ tetrahedra, which are linked by corners to form a three dimensional network, with a space group R3-barC. Some workers have already described that the conductivity increased considerably if Ti/sup 4+/ in LiTi/sub 2/(PO/sub 4/)/sub 3/ was substituted by slightly larger cations such as Ga/sup 3+/(1),Sc/sup 3+/(2), and In/sup 3+/(3,4). These results are similar to each other because of their close ionic radii. In this communication, substitution effects of Ti/sup 4+/ in LiTi/sub 2/(PO/sub 4/)/sub 3/ by various ions (Al/sup 3+/, Sc/sup 3+/, Y/sup 3+/, and La/sup 3+/) on their conductivities are reported

Facile synthesis of hierarchically porous Li{sub 4}Ti{sub 5}O{sub 12} microspheres for high rate lithium ion batteries

Energy Technology Data Exchange (ETDEWEB)

Shen, L.F.; Luo, H.J.; Yuan, C.Z.; Su, X.F.; Xu, K.; Zhang, X.G. [Nanjing Univ. of Aeronautics and Astronautics (China). College of Material Science and Engineering

2010-07-01

Lithium-ion (Li-ion) batteries are used in electric vehicles (EVs) and hybrid electric vehicles (HEVs) due to their excellent energy storage capacity. Graphite is widely used as an anode material in EV and HEV applications. This study investigated the use of a lithium-titanium alloy (Li{sub 4}Ti{sub 5}O{sub 12}) designed to avoid reductions of the electrolyte on the surface of the electrode. The study showed that the composite material shows excellent cycling performance, excellent reversibility, structural stability, and Li-ion mobility in the charge-discharge process. A simple template-free hydrothermal method for fabricating Li{sub 4}Ti{sub 5}O{sub 12} hierarchical microspheres assembled by uniform nanoparticles was presented. The 1-step process produced microspheres with a high yield and uniform diameter. Details of the synthesis process, and the electrochemical and structural properties of the resulting materials were presented. 5 refs.

Study of LiTiMg-ferrite radome for the application of satellite communication

International Nuclear Information System (INIS)

Saxena, Naveen Kumar; Kumar, Nitendar; Pourush, P.K.S.

2010-01-01

In this paper the characteristics of LiTiMg-ferrite radome are presented. A thin layer of LiTiMg-ferrite is used as superstrate or radome, which controls the radiation, reception, and scattering from a printed antenna or array by applying a dc magnetic bias field in the plane of the ferrite, orthogonal to the RF magnetic field. In this analysis absorbing and transmission power coefficients are calculated to obtain the power loss and transmitted power through the radome layer respectively. The absorbing power coefficient verifies the switching behavior of radome for certain range of applied external magnetic field (Ho), which depends on the resonance width parameter (ΔH) of ferrite material. By properly choosing the bias field, electromagnetic wave propagation in the ferrite layer can be made zero or negligible over a certain frequency range, resulting in switching behavior of the ferrite layer. In this communication we also show precise preparation of radome layer and present its electric and magnetic properties along with its Curie temperature, which shows the working efficiency of layer under extreme situation. This radome layer can be very useful for the sensitive and smart communication systems.

Localized transitions in the thermoluminescence of LiF : Mg,Ti: potential for nanoscale dosimetry

CERN Document Server

Horowitz, Y S; Biderman, S; Einav, Y

2003-01-01

We describe the effect of nanoscale spatially coupled trapping centre (TC)-luminescent centre (LC) pairs on the thermoluminescence (TL) properties of LiF : Mg,Ti. It is shown that glow peak 5a (a low-temperature satellite of the major glow peak 5) arises from localized electron-hole (e-h) recombination in a TC-LC pair believed to be based on Mg sup 2 sup + -Li sub v sub a sub c trimers (the TCs) coupled to Ti(OH) sub n molecules (the LCs). Due to the localized nature of the e-h pair, two important properties are affected: (i) heavy charged particle (HCP) TL efficiency: the intensity of peak 5a relative to peak 5 following HCP high-ionization density irradiation is greater than that following low ionization density irradiation in a manner somewhat similar to the ionization density dependence of the yield of double-strand breaks (DSBs) induced in DNA. Our experimental measurements in a variety of HCP and fast neutron radiation fields have demonstrated that the ratio of glow peaks 5a/5 is nearly independent of p...

A new, high energy rechargeable lithium ion battery with a surface-treated Li1.2Mn0.54Ni0.13Co0.13O2 cathode and a nano-structured Li4Ti5O12 anode

International Nuclear Information System (INIS)

Liu, Xiaoyu; Huang, Tao; Yu, Aishui

2015-01-01

Through elaborate design, a new rechargeable lithium ion battery has been developed by comprising a surface-treated Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode and a nano-structured Li 4 Ti 5 O 12 anode. After precondition Na 2 S 2 O 8 treatment, the initial coulombic efficiency of Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode has been significantly increased and can be compatible with that of the nano-structured Li 4 Ti 5 O 12 anode. The optimization of structure and morphology for both active electrode materials result in their remarkable electrochemical performances in respective lithium half-cells. Ultimately, the rechargeable lithium ion full battery consisting of both electrodes delivers a specific capacity of 99.0 mAh g −1 and a practical energy density of 201 Wh kg −1 , based on the total weight of both active electrode materials. Furthermore, as a promising candidate in the lithium ion battery field, this full battery also achieves highly attractive electrochemical performance with high coulombic efficiency, excellent cycling stability and outstanding rate capability. Thus the proposed battery displays broad practical application prospects for next generation of high-energy lithium ion battery. - Highlights: • The Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode is surface-treated by Na 2 S 2 O 8 . • The nano-sized Li 4 Ti 5 O 12 anode is obtained by a solid-state method. • A new Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 /Li 4 Ti 5 O 12 lithium ion battery is developed. • The battery shows high coulombic efficiency, specific capacity and energy density. • The battery shows high capacity retention rate and good high-rate capability

Study of surface reaction of spinel Li4Ti5O12 during the first lithium insertion and extraction processes using atomic force microscopy and analytical transmission electron microscopy.

Science.gov (United States)

Kitta, Mitsunori; Akita, Tomoki; Maeda, Yasushi; Kohyama, Masanori

2012-08-21

Spinel lithium titanate (Li(4)Ti(5)O(12), LTO) is a promising anode material for a lithium ion battery because of its excellent properties such as high rate charge-discharge capability and life cycle stability, which were understood from the viewpoint of bulk properties such as small lattice volume changes by lithium insertion. However, the detailed surface reaction of lithium insertion and extraction has not yet been studied despite its importance to understand the mechanism of an electrochemical reaction. In this paper, we apply both atomic force microscopy (AFM) and transmission electron microscopy (TEM) to investigate the changes in the atomic and electronic structures of the Li(4)Ti(5)O(12) surface during the charge-discharged (lithium insertion and extraction) processes. The AFM observation revealed that irreversible structural changes of an atomically flat Li(4)Ti(5)O(12) surface occurs at the early stage of the first lithium insertion process, which induces the reduction of charge transfer resistance at the electrolyte/Li(4)Ti(5)O(12) interface. The TEM observation clarified that cubic rock-salt crystal layers with a half lattice size of the original spinel structure are epitaxially formed after the first charge-discharge cycle. Electron energy loss spectroscopy (EELS) observation revealed that the formed surface layer should be α-Li(2)TiO(3). Although the transformation of Li(4)Ti(5)O(12) to Li(7)Ti(5)O(12) is well-known as the lithium insertion reaction of the bulk phase, the generation of surface product layers should be inevitable in real charge-discharge processes and may play an effective role in the stable electrode performance as a solid-electrolyte interphase (SEI).

Investigation of radiation-enhanced oxygen diffusion in Li-Ti ferrites

International Nuclear Information System (INIS)

Surzhikov, A.P.; Pritulov, A.M.; Gyngazov, S.A.; Lysenko, E.N.

1999-01-01

The radiation-enhanced oxygen diffusion in polycrystalline Li-Ti ferrites was investigated. The electron accelerator ELV-6 (Institute of Nuclear Physics, Russian Academy of Sciences) was used to generate the radiothermal annealing. The radiation effects were established by comparison of diffusion profiles of the samples, which were radiothermally treated, and data obtained during the thermal annealing in the resistance furnace. It was discovered that there was an increase of numerical values of Ed (activation diffusion energy) and Do (preexponential factor) during the radiothermal annealing, if compared with the thermal one. The investigations were financed by the Russian Fundamental Research Fund

Effect of Acetylene Black Content in Li4Ti5O12 Xerogel Solid-State Anode Materials on Half-Cell Li-ion Batteries Performance

Science.gov (United States)

Abdurrahman, N. M.; Priyono, B.; Syahrial, A. Z.; Subhan, A.

2017-07-01

The effect of Acetylene Black (AB) additive contents in lithium titanate/Li4Ti5O12 (LTO) anode on Li-ion Batteries performance is studied in this work. The LTO active material for Li-ion batteries anode was successfully synthesized using sol-gel method to form TiO2 xerogel continued by mixing process with LiOH in ball-mill and then sintered to obtain spinel LTO. The LTO powder is characterized by X-Ray Diffraction (XRD), scanning electron microscopy-Energy Dispersive Spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET). The spinel LTO and TiO2 rutile were detected by XRD diffractogram. The LTO powder is in the form of agglomerates structure. This powder then was mixed with PVDF binder (10%wt) and AB additives with various amount from 10%wt (LTO2 Ac-1), 12%wt (LTO2 Ac-2), and 15%wt (LTO2 Ac-3) of total weight solid content to form electrode sheet. Half-cell coin battery was made with lithium metal foil as a counter electrode. Cyclic voltammetry (CV), Electrochemical-impedance spectroscopy (EIS), and charge discharge (CD) test used to examine the battery performance. The highest resistance value is obtained in LTO2 Ac-3 sample with 15%wt of AB. It might be caused by the formation of side reaction product on electrode surface at initial cycle due to high reactivity of LTO2 Ac-3 electrode. The highest initial capacity at CV test and CD test was obtained in LTO2 Ac-1 (10%wt AB) sample, due to the best proportion of active material content in the compound. While, in the charge-discharge test at high current rate, the best sample rate-capability performance belongs to LTO2 Ac-3 sample (15%wt AB), which still have 24.12 mAh/g of discharge capacity at 10 C with 71.34% capacity loss.

Structure and electrochemical performances of LiFe{sub 1−2x}Ti{sub x}PO{sub 4}/C cathode doped with high valence Ti{sup 4+} by carbothermal reduction method

Energy Technology Data Exchange (ETDEWEB)

Fan, Chang-ling, E-mail: clfanhd@yahoo.com.cn [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Han, Shao-chang [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Li, Ling-fang [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); College of Mechanical Engineering, Hunan University of Art and Science, Changde 415000 (China); Bai, Yong-mei [Equipment Manufacturing College, Hebei University of Engineering, Handan 056038 (China); Zhang, Ke-he; Chen, Jin; Zhang, Xiang [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China)

2013-11-05

Highlights: •LiFePO{sub 4}/C and LiFe{sub 1−2x}Ti{sub x}PO{sub 4}/C are prepared by carbothermal reduction method. •Phenol–formaldehyde resin is used as reducing agent and carbon source. •Mechanism of carbothermal reduction reaction is presented on the basis of TG–DSC. •The electrochemical performances of samples are systematically investigated. -- Abstract: LiFePO{sub 4}/C (LFPC) and LiFe{sub 1−2x}Ti{sub x}PO{sub 4}/C (LFTPC) were prepared by carbothermal reduction method using FePO{sub 4}·2H{sub 2}O as iron source and phenol–formaldehyde resin as reducing agent and carbon source. Different ratios of TiO{sub 2} (IV) with high valence and small radius were applied to dope LiFePO{sub 4} to enhance its electrochemical performances. Results show that LFPC and LFTPC are synthesized successfully by carbothermal reduction method. The optimal carbon content in LFPC is 5 wt.% and its discharge capacity at 0.1 C is 150.8 mA h g{sup −1}. The crystallite structure of LFTPC becomes stable. They possess the smaller particle size compared with LiFePO{sub 4}. LFTPC-2 possesses the best C-rate and cycle performances among all the samples. Its discharge capacities at 0.1 C, 1 C and 3 C are 132.7 mA h g{sup −1}, 98.7 mA h g{sup −1} and 83.1 mA h g{sup −1}. The discharge curve can maintain its stable and flat platform of 3.3 V at 3 C. The electronic conductivity of LFTPC, which is coated with carbon and doped with Ti, can reach ∼10{sup −4} S cm{sup −1}. The charge transfer resistance of LFTPC-2 is 33.68 Ω, which is much lower than that of other samples.

Adhesive PEG-based binder for aqueous fabrication of thick Li4Ti5O12 electrode

International Nuclear Information System (INIS)

Tran, Binh; Oladeji, Isaiah O.; Wang, Zedong; Calderon, Jean; Chai, Guangyu; Atherton, David; Zhai, Lei

2013-01-01

We report the first fully compressed Li 4 Ti 5 O 12 electrode designed by an aqueous process. An adhesive, elastomeric, and lithium ion conductive PEG-based copolymer is used as a binder for the aqueous fabrication thick, flexible, and densely packed Li 4 Ti 5 O 12 (LTO) electrodes. Self-adherent cathode films exceeding 200 μm in thickness and withholding high active mass loadings of 28 mg/cm 2 deliver 4.2 mAh/cm 2 at C/2 rate. Structurally defect-free electrodes are fabricated by casting aqueous cathode slurries onto nickel foam, dried, and hard-calendared at 10 tons/cm 2 . As a multifunctional material, the binder is synthesized by the copolymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA), methyl methacrylate (MMA), and isobutyl vinyl ether (IBVE) in optimal proportions. Furthermore, coordinating the binder with lithium salt is necessary for the electrode to function

Chemical composition-tailored Li{sub x}Ti{sub 0.1}Ni{sub 1−x}O ceramics with enhanced dielectric properties

Energy Technology Data Exchange (ETDEWEB)

Puli, Venkata Sreenivas, E-mail: pvsri123@gmail.com [Department of Mechanical Engineering, University of Texas, El Paso, TX 79968 (United States); Orozco, Cristian [Department of Mechanical Engineering, University of Texas, El Paso, TX 79968 (United States); Picchini, Randall [Department of Electrical Engineering, University of California, Santa Barbara, CA 93106-512 (United States); Ramana, C.V. [Department of Mechanical Engineering, University of Texas, El Paso, TX 79968 (United States)

2016-12-01

This paper reports on the synthesis of polycrystalline (Li,Ti)-doped NiO powders (i.e., Li{sub x}Ti{sub 0.1}Ni{sub 1−x}O, abbreviated as LTNO) by the solid-state synthesis method. Note that, the doping concentration of Ti is kept constant (x∼0.10) in the stoichiometry, the difference in the material behavior of LTNO samples can only be attributed to the effect of Li. X-ray diffraction patterns confirmed a cubic rock-salt structured NiO-based phase with the presence of minor NiTiO{sub 3} phase, were reported elsewhere [Venkata et al., Chem. Phys. Lett., 649 (2016) 115–118.]. Dense microstructures were obtained using ultra high resolution scanning electron microscope. A high dielectric constant (ε∼10{sup 4}) near room temperature at low-frequency was observed in LTNO ceramics. Weak temperature dependence of dielectric constant over the measured compositions (x = 0 to 0.10) was observed in the LTNO ceramics. A giant dielectric constant of 10{sup 4}–10{sup 5} at high temperatures (120–170 °C) for certain LTNO compositions (x = 0.15 to 0.3) was observed in the sintered ceramics. The origin of the high dielectric constant observed in these LTNO ceramics is attributed to the Maxwell–Wagner polarization mechanism and a thermally activated mechanism. - Highlights: • Li content strongly influences the structure and dielectric properties. • Li-incorporation enhances the dielectric properties of LTNO. • A giant dielectric constant of 10{sup 4}–10{sup 5} at high temperatures (120–170 °C). • Giant dielectric constant is attributed to the Maxwell–Wagner polarization. • NTCR behavior is also confirmed from impedance spectroscopy results.

Synthesis and Electrochemical Performance of Graphene Wrapped SnxTi1−xO2 Nanoparticles as an Anode Material for Li-Ion Batteries

Directory of Open Access Journals (Sweden)

Xing Xin

2015-01-01

Full Text Available Ever-growing development of Li-ion battery has urged the exploitation of new materials as electrodes. Here, SnxTi1-xO2 solid-solution nanomaterials were prepared by aqueous solution method. The morphology, structures, and electrochemical performance of SnxTi1-xO2 nanoparticles were systematically investigated. The results indicate that Ti atom can replace the Sn atom to enter the lattice of SnO2 to form substitutional solid-solution compounds. The capacity of the solid solution decreases while the stability is improved with the increasing of the Ti content. Solid solution with x of 0.7 exhibits the optimal electrochemical performance. The Sn0.7Ti0.3O2 was further modified by highly conductive graphene to enhance its relatively low electrical conductivity. The Sn0.7Ti0.3O2/graphene composite exhibits much improved rate performance, indicating that the SnxTi1-xO2 solid solution can be used as a potential anode material for Li-ion batteries.

Improving the fast discharge performance of high-voltage LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} spinel by Cu{sup 2+}, Al{sup 3+}, Ti{sup 4+} tri-doping

Energy Technology Data Exchange (ETDEWEB)

Deng, Jicheng [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an (China); Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi' an Jiaotong University, Xi' an (China); Xu, Youlong, E-mail: ylxuxjtu@mail.xjtu.edu.cn [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an (China); Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi' an Jiaotong University, Xi' an (China); Xiong, Lilong; Li, Liang [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an (China); Sun, Xiaofei [Shaanxi Engineering Research Center of Advanced Energy Materials & Devices, Xi' an Jiaotong University, Xi' an (China); Zhang, Yuan [Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi' an Jiaotong University, Xi' an (China)

2016-08-25

The sluggish Li{sup +} ion diffusion coefficient at ∼4.7 V (vs. Li{sup +}/Li) greatly impairs the fast discharge performance of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} cathode material. Herein, a tri-doping strategy is proposed where Cu{sup 2+}, Al{sup 3+}, Ti{sup 4+} ions are partially substituted for Ni{sup 2+} and Mn{sup 4+}. Cu{sup 2+}, Al{sup 3+}, Ti{sup 4+} tri-doping effectively suppresses the Li{sub x}Ni{sub 1−x}O impurity phase, increases the cation mixing in the octahedral B-site in the spinel, enlarges the electronic conductivity, and enhances the structural stability. Most importantly, the Li{sup +} diffusion coefficients show a peculiar boost at 4.7 V by two orders of magnitude after tri-doping. Compared to the pristine LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (denoted P-LNM), the tri-doped Li[Ni{sub 0.455}Cu{sub 0.03}Al{sub 0.03}Mn{sub 1.455}Ti{sub 0.03}]O{sub 4} (denoted TD-LNM) exhibits much better fast discharge performance, delivering a specific capacity of ∼101 mAh g{sup −1} at 100 C discharge rate. - Graphical abstract: For the LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} cathode material, the sluggish Li{sup +} ion diffusion coefficient around the ∼4.7 V (vs. Li{sup +}/Li) plateau greatly impair its fast discharge performance, which therefore limit its application in electric vehicles. Herein, a tri-doping strategy is proposed where Cu{sup 2+}, Al{sup 3+}, Ti{sup 4+} ions are partially substituted for Ni{sup 2+} and Mn{sup 4+}. After tri-doping, the Li{sup +} diffusion coefficient at 4.7 V (vs. Li{sup +}/Li) is boosted by two orders of magnitude. Compared to the pristine LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (denoted P-LNM), the tri-doped Li[Ni{sub 0.455}Cu{sub 0.03}Al{sub 0.03}Mn{sub 1.455}Ti{sub 0.03}]O{sub 4} (denoted TD-LNM) exhibits much better fast discharge performance, delivering a capacity of ∼101 mAh·g{sup −1} at 100 C discharge rate. - Highlights: • Cu, Al, Ti Tri-doping improves electronic conductivity of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4}. • Cu

The three-cluster structures in 7Li

International Nuclear Information System (INIS)

Beck, R.; Krivec, R.; Mihailovic, M.V.; Kernforschungszentrum Karlsruhe G.m.b.H.

1981-01-01

A cluster model for the description of light nuclei is investigated which includes the interplay of three-cluster structures with the two-cluster ones and allows molecule-like vibrations of clusters. It is applied to the nucleus 7 Li in order to study the influence of the trhee-cluster structures of the type ( 4 He- 2 H-n) on the low-lying states previously described by two-cluster structures ( 4 He- 3 H) and ( 6 Li-n). An effective central interaction is used in the calculation. The structure of the nucleus 7 Li is described by the two-cluster configuration ( 4 He- 3 H) and the three-cluster configurations ( 4 He- 2 H(Isub(d))-n), with Isub(d) = 0, 1, and the total spin I = 1/2, 3/2. In the wave function of three-cluster structure the pair of values L 1 = 0, L 2 = 1 only is included. The effective nuclear potential V2 of Volkov is used in the calculation. The energy of the ground state described by a single configuration of the two-cluster structure ( 4 He- 3 H) is lowered by 0.66 MeV when this configuration is coupled to two three-cluster configurations and the molecule-like vibration is allowed through solving the Hill-Wheeler equation. Both mechanism have approximately equal effects. The ground-state energy (-38.14 MeV) is 0.3 MeV lower than in the model which describes the 7 Li by a superposition of two-cluster structures ( 4 He- 3 H) and ( 6 Li-n). (orig./HSI)

The influence of irradiation defects on tritium release from Li{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Satoru; Grishmanov, V [Tokyo Univ. (Japan). Faculty of Engineering

1996-10-01

During reactor irradiation of Li{sub 2}O defects are introduced by neutrons, triton and helium ions produced by {sup 6}Li(n, {alpha}){sup 3}H reactions and {gamma}-rays. Simultaneous measurements of luminescence emission and tritium release were performed under various conditions (temperature, sweep gas chemical composition) for Li{sub 2}O single crystal and polycrystal in order to elucidate possible influence of defects on tritium release. (author)

Pre- and post-irradiation fading effect for LiF:Mg,Ti and LiF:Mg,Cu,P materials used in routine monitoring

International Nuclear Information System (INIS)

Carinou, E.; Askounis, P.; Dimitropoulou, F.; Kiranos, G.; Kyrgiakou, H.; Nirgianaki, E.; Papadomarkaki, E.; Kamenopoulou, V.

2011-01-01

LiF is a well-known thermoluminescent (TL) material used in individual monitoring, and its fading characteristics have been studied for years. In the present study, the fading characteristics (for a period of 150 d) of various commercial LiF materials with different dopants have been evaluated. The materials used in the study are those used in routine procedures by the Personal Dosimetry Dept. of Greek Atomic Energy Commission and in particular, LiF:Mg,Ti (MTS-N, TL Poland), LiF:Mg,Cu,P (MCP-N, TL Poland), LiF:Mg,Cu,P (MCP-Ns, thin active layer detector, TL Poland) and LiF:Mg,Cu,P (TLD100H, Harshaw). The study showed that there is a sensitivity loss in signal of up to 20 % for the MTS-N material for a 150-d period in the pre-irradiation fading phase. The MCP-N has a stable behaviour in the pre-irradiation fading phase, but this also depends on the readout system. As far as the post-irradiation fading effect is concerned, a decrease of up to 20 % for the MTS-N material is observed for the same time period. On the other hand, the LiF:Mg,Cu,P material presents a stable behaviour within ±5 %. These results show that the fading effect is different for each material and should be taken into account when estimating doses from dosemeters that are in use for >2 months. (authors)

Li4Ti5O12/graphene nanoribbons composite as anodes for lithium ion batteries

CSIR Research Space (South Africa)

Medina IV, PA

2015-10-01

Full Text Available of GNRs was observed to have significantly improved the rate per- formance of LTO/GNTs. The specific capacities determined of the obtained composite at rates of 0.2, 0.5, 1, 2, and 5 C are 206.5, 200.9, 188, 178.1 and 142.3 mAh·g−1, respectively...- ated with unmodified Li4Ti5O12 is its poor rate per- formance, resulting from its inherent low electronic conductivity and moderate Li+ diffusion coefficient (Kavan et al. 2003; Wagemaker et al. 2008; Ouyang et al. 2007). Numerous strategies amongst...

Eosin yellowish dye sensitized TiO2 solar cell with PEG/PEO/LiI/I2 as electrolyte

Science.gov (United States)

Kanmani, S. S.; Umapathy, S.; Ramachandran, K.

2012-06-01

Eosin Yellowish dye sensitized TiO2 nanoparticles (NP) and nanowires (NW) are employed as photo anodes in dye sensitized solar cells with PEO/PEG/LiI/I2 as electrolyte. Material characterization by XRD and SEM confirms the formation of anatase phased TiO2 NP and NW. Effective quenching of UV emission in TiO2 NW than NP is a consequence of reduction in recombination rate, which directly favours for better solar conversion efficiency. The photovoltaic performance of TiO2 NW with an overall conversion efficiency of 0.31 % is better than NP, which is the outcome of improved electron transport in NW.

Hierarchical carbon-coated acanthosphere-like Li4Ti5O12 microspheres for high-power lithium-ion batteries

Science.gov (United States)

Sha, Yujing; Xu, Xiaomin; Li, Li; Cai, Rui; Shao, Zongping

2016-05-01

In this work, carbon-coated hierarchical acanthosphere-like Li4Ti5O12 microspheres (denoted as AM-LTO) were prepared via a two-step hydrothermal process with low-cost glucose as the organic carbon source. The hierarchical porous microspheres had open structures with diameters of 4-6 μm, which consisted of a bunch of willow leaf-like nanosheets. Each nanosheet was comprised of Li4Ti5O12 nanoparticles that are 20 nm in size and coated by a thin carbon layer. When applied as the anode material for lithium-ion batteries (LIBs), the AM-LTO presented outstanding rate and cycling performance due to its unique morphologies. A high capacity of 145.6 mAh g-1 was achieved for AM-LTO at a rate of 40C (1C = 175 mAh g-1). In contrast, the sample synthesized without glucose as carbon source (denoted as S-LTO) experienced an obvious structural collapse during the hydrothermal reaction and presented a specific capacity of only 67 mAh g-1 at 1C, which further decreased to 14 mAh g-1 at 40C. Further morphological growth of the acanthosphere-like Li4Ti5O12 microspheres and their excellent performance as an anode in LIBs were also discussed in this work.

Electrochemistry and safety of Li 4Ti 5O 12 and graphite anodes paired with LiMn 2O 4 for hybrid electric vehicle Li-ion battery applications

Science.gov (United States)

Belharouak, Ilias; Koenig, Gary M.; Amine, K.

A promising anode material for hybrid electric vehicles (HEVs) is Li 4Ti 5O 12 (LTO). LTO intercalates lithium at a voltage of ∼1.5 V relative to lithium metal, and thus this material has a lower energy compared to a graphite anode for a given cathode material. However, LTO has promising safety and cycle life characteristics relative to graphite anodes. Herein, we describe electrochemical and safety characterizations of LTO and graphite anodes paired with LiMn 2O 4 cathodes in pouch cells. The LTO anode outperformed graphite with regards to capacity retention on extended cycling, pulsing impedance, and calendar life and was found to be more stable to thermal abuse from analysis of gases generated at elevated temperatures and calorimetric data. The safety, calendar life, and pulsing performance of LTO make it an attractive alternative to graphite for high power automotive applications, in particular when paired with LiMn 2O 4 cathode materials.

Fabrication of lead-free piezoelectric Li2CO3-added (Ba,Ca)(Ti,Sn)O3 ceramics under controlled low oxygen partial pressure and their properties

Science.gov (United States)

Noritake, Kouta; Sakamoto, Wataru; Yuitoo, Isamu; Takeuchi, Teruaki; Hayashi, Koichiro; Yogo, Toshinobu

2018-02-01

Reduction-resistant lead-free (Ba,Ca)(Ti,Sn)O3 piezoceramics with high piezoelectric constants were fabricated by optimizing the amount of Li2CO3 added. Oxygen partial pressure was controlled during the sintering of (Ba,Ca)(Ti,Sn)O3 ceramics in a reducing atmosphere using H2-CO2 gas. Enhanced grain growth and a high-polarization state after poling treatment were achieved by adding Li2CO3. Optimizing the amount of Li2CO3 added to (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics sintered under a low oxygen partial pressure resulted in improved piezoelectric properties while maintaining the high sintered density. The prepared Li2CO3-added ceramic samples had homogeneous microstructures with a uniform dispersion of each major constituent element. However, the residual Li content in the 3 mol % Li2CO3-added (Ba0.95Ca0.05)(Ti0.95Sn0.05)O3 ceramics after sintering was less than 0.3 mol %. Sintered bodies of this ceramic prepared in a CO2 (1.5%)-H2 (0.3%)/Ar reducing atmosphere (PO2 = 10-8 atm at 1350 °C), exhibited sufficient electrical resistivity and a piezoelectric constant (d 33) exceeding 500 pC/N. The piezoelectric properties of this nonreducible ceramic were comparable or superior to those of the same ceramic sintered in air.

Li-ion batteries from LiFePO{sub 4} cathode and anatase/graphene composite anode for stationary energy storage

Energy Technology Data Exchange (ETDEWEB)

Choi, Daiwon; Wang, Donghai; Viswanathan, Vish V.; Wang, Wei; Nie, Zimin; Zhang, Ji-Guang; Graff, Gordon L.; Liu, Jun; Yang, Zhenguo [Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99352 (United States); Bae, In-Tae [Small Scale Systems Integration and Packaging Center, State University of New York at Binghamton, P.O. Box 6000, Binghamton, NY 13902 (United States); Duong, Tien [US Departments of Energy, 1000 Independence Ave., Washington, DC 20858 (United States)

2010-03-15

Li-ion batteries made from LiFePO{sub 4} cathode and anatase TiO{sub 2}/graphene composite anode were investigated for potential application in stationary energy storage. Fine-structured LiFePO{sub 4} was synthesized by a novel molten surfactant approach whereas anatase TiO{sub 2}/graphene nanocomposite was prepared via self-assembly method. The full cell that operated at 1.6 V demonstrated negligible fade even after more than 700 cycles at measured 1 C rate. While with relative lower energy density than traditional Li-ion chemistries interested for vehicle applications, the Li-ion batteries based on LiFePO{sub 4}/TiO{sub 2} combination potentially offers long life and low cost, along with safety, all which are critical to the stationary applications. (author)

Dehydrogenation of Surface-Oxidized Mixtures of 2LiBH4 + Al/Additives (TiF3 or CeO2

Directory of Open Access Journals (Sweden)

Juan Luis Carrillo-Bucio

2017-11-01

Full Text Available Research for suitable hydrogen storage materials is an important ongoing subject. LiBH4–Al mixtures could be attractive; however, several issues must be solved. Here, the dehydrogenation reactions of surface-oxidized 2LiBH4 + Al mixtures plus an additive (TiF3 or CeO2 at two different pressures are presented. The mixtures were produced by mechanical milling and handled under welding-grade argon. The dehydrogenation reactions were studied by means of temperature programmed desorption (TPD at 400 °C and at 3 or 5 bar initial hydrogen pressure. The milled and dehydrogenated materials were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, and Fourier transformed infrared spectroscopy (FT-IR The additives and the surface oxidation, promoted by the impurities in the welding-grade argon, induced a reduction in the dehydrogenation temperature and an increase in the reaction kinetics, as compared to pure (reported LiBH4. The dehydrogenation reactions were observed to take place in two main steps, with onsets at 100 °C and 200–300 °C. The maximum released hydrogen was 9.3 wt % in the 2LiBH4 + Al/TiF3 material, and 7.9 wt % in the 2LiBH4 + Al/CeO2 material. Formation of CeB6 after dehydrogenation of 2LiBH4 + Al/CeO2 was confirmed.

MYCN-driven regulatory mechanisms controlling LIN28B in neuroblastoma

Science.gov (United States)

Beckers, Anneleen; Van Peer, Gert; Carter, Daniel R.; Gartlgruber, Moritz; Herrmann, Carl; Agarwal, Saurabh; Helsmoortel, Hetty H.; Althoff, Kristina; Molenaar, Jan J.; Cheung, Belamy B.; Schulte, Johannes H.; Benoit, Yves; Shohet, Jason M.; Westermann, Frank; Marshall, Glenn M.; Vandesompele, Jo; De Preter, Katleen; Speleman, Frank

2016-01-01

LIN28B has been identified as an oncogene in various tumor entities, including neuroblastoma, a childhood cancer that originates from neural crest-derived cells, and is characterized by amplification of the MYCN oncogene. Recently, elevated LIN28B expression levels were shown to contribute to neuroblastoma tumorigenesis via let-7 dependent de-repression of MYCN. However, additional insight in the regulation of LIN28B in neuroblastoma is lacking. Therefore, we have performed a comprehensive analysis of the regulation of LIN28B in neuroblastoma, with a specific focus on the contribution of miRNAs. We show that MYCN regulates LIN28B expression in neuroblastoma tumors via two distinct parallel mechanisms. First, through an unbiased LIN28B-3′UTR reporter screen, we found that miR-26a-5p and miR-26b-5p regulate LIN28B expression. Next, we demonstrated that MYCN indirectly affects the expression of miR-26a-5p, and hence regulates LIN28B, therefor establishing a MYCN-miR-26a-5p-LIN28B regulatory axis. Second, we provide evidence that MYCN regulates LIN28B expression via interaction with the LIN28B promotor, establishing a direct MYCN-LIN28B regulatory axis. We believe that these findings mark LIN28B as an important effector of the MYCN oncogenic phenotype and underlines the importance of MYCN-regulated miRNAs in establishing the MYCN-driven oncogenic process. PMID:26123663

Ceramic thick film humidity sensor based on MgTiO3 + LiF

International Nuclear Information System (INIS)

Kassas, Ahmad; Bernard, Jérôme; Lelièvre, Céline; Besq, Anthony; Guhel, Yannick; Houivet, David; Boudart, Bertrand; Lakiss, Hassan; Hamieh, Tayssir

2013-01-01

Graphical abstract: - Highlights: • The fabricated sensor based on MgTiO 3 + LiF materials used the spin coating technology. • The response time is 70 s to detect variation between 5 and 95% relative humidity. • The addition of Scleroglucan controls the viscosity and decreases the roughness of thick film surface. • This humidity sensor is a promising, low-cost, high-quality, reliable ceramic films, that is highly sensitive to humidity. - Abstract: The feasibility of humidity sensor, consisting of a thick layer of MgTiO 3 /LiF materials on alumina substrate, was studied. The thermal analysis TGA-DTGA and dilatometric analysis worked out to confirm the sintering temperature. An experimental plan was applied to describe the effects of different parameters in the development of the thick film sensor. Structural and microstructural characterizations of the developed thick film were made. Rheological study with different amounts of a thickener (scleroglucan “sclg”), showing the behavior variation, as a function of sclg weight % was illustrated and rapprochement with the results of thickness variation as a function of angular velocity applied in the spin coater. The electrical and dielectric measurements confirmed the sensitivity of the elaborated thick film against moisture, along with low response time

Iodine Deficiency in a Study Population of Norwegian Pregnant Women-Results from the Little in Norway Study (LiN).

Science.gov (United States)

Dahl, Lisbeth; Wik Markhus, Maria; Sanchez, Perla Vanessa Roldan; Moe, Vibeke; Smith, Lars; Meltzer, Helle Margrete; Kjellevold, Marian

2018-04-20

Iodine sufficiency is particularly important in pregnancy, where median urinary iodine concentration (UIC) in the range of 150⁻250 µg/L indicates adequate iodine status. The aims of this study were to determine UIC and assess if dietary and maternal characteristics influence the iodine status in pregnant Norwegian women. The study comprises a cross-sectional population-based prospective cohort of pregnant women (Little in Norway (LiN)). Median UIC in 954 urine samples was 85 µg/L and 78.4% of the samples ( n = 748) were ≤150 µg/L. 23.2% ( n = 221) of the samples were ≤50 µg/L and 5.2% ( n = 50) were above the requirements of iodine intake (>250 µg/L). Frequent iodine-supplement users ( n = 144) had significantly higher UIC (120 µg/L) than non-frequent users (75 µg/L). Frequent milk and dairy product consumers (4⁻9 portions/day) had significantly higher UIC (99 µg/L) than women consuming 0⁻1 portion/day (57 µg/L) or 2⁻3 portions/day (83 µg/L). Women living in mid-Norway ( n = 255) had lowest UIC (72 µg/L). In conclusion, this study shows that the diet of the pregnant women did not necessarily secure a sufficient iodine intake. There is an urgent need for public health strategies to secure adequate iodine nutrition among pregnant women in Norway.

The results of dosimetric type tests on the sample of LiF:Mg,Ti thermoluminescence dosimeters produced in Iran

International Nuclear Information System (INIS)

Jafarizadeh, M.; Hosseini Pooya, S. M.; Firoozi, B.; Kamali Shoroodani, A. R.; Mohammadi, Kh.

2011-01-01

In this investigation, the standard type tests performed on the LiF:Mg,Ti chip samples which have been produced in Iran. The dosimetry tests are consisting of sensitivity, homogeneity, linearity, reproducibility, minimum measurable dose, self and residual doses. The obtained results show that some of the tests such as sensitivity, minimum measurable dose, self and residual doses fulfill the criteria given by IEC 61066 and ASTM E668 standards; however, the remaining tests show some discrepancies in comparison with the standards. Also the sensitivity was measured to be 0.92 of that of commercially available TLD-100 (Harshaw) sample. So, the produced LiF:Mg,Ti dosimeter can be used in a routine personal/environmental and medical dosimetry with considering its precision.

Luminescent emission of LiF: Mg, Ti exposed to UV radiation; Emision luminiscente del LiF: Mg, Ti expuesto a la radiacion UV

Energy Technology Data Exchange (ETDEWEB)

Estrada G, A. [Estudiante de Facultad de Ciencias, UNAM, Circuito Exterior, 04500 Mexico D.F. (Mexico); Castano M, V.M. [Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, Campus Juriquilla, Queretaro (Mexico); Cruz Z, E.; Garcia F, F. [Instituto de Ciencias Nucleares UNAM, A.P. 70-543 Mexico D.F. (Mexico)

2002-07-01

It was investigated the luminescent emission stimulated by heat (Tl) of LiF: Mg, Ti crystals which were exposed to UV radiation coming from a mercury lamp. Since this crystal depends on the thermal history, it has been used a thermal treatment consisting of a baking at 380 C during one hour for each reading and they were irradiated with UV. The brilliance curves between 5 and 840 minutes of exposure in the face of UV light were obtained. An important loss in the response, starting from 150 minutes of irradiation was observed. Also the relative intensity of the brilliance curve decay when the crystals being stored in darkness and room temperature conditions, which is according to the results in the literature about. (Author)

Pressure-composition isotherms and thermodynamic properties of TiF{sub 3}-enhanced Na{sub 2}LiAlH{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Fossdal, A. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)]. E-mail: anita.fossdal@ife.no; Brinks, H.W. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway); Fonnelop, J.E. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, B.C. [Department of Physics, Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)

2005-07-19

The mixed alanate Na{sub 2}LiAlH{sub 6} was prepared by ball-milling and subsequent heat-treatment under H{sub 2} pressure. After the synthesis, 2 mol% TiF{sub 3} was added by ball-milling. Pressure-composition isotherms were measured for the Ti-enhanced material in the temperature range of 170-250 deg C. A van't Hoff plot was constructed using the equilibrium desorption plateau pressures. From this plot, a dissociation enthalpy of 56.4 {+-} 0.4 kJ/mol H{sub 2} and a corresponding entropy of 137.9 {+-} 0.7 J/K mol H{sub 2} was found for Na{sub 2}LiAlH{sub 6}.

Recovery of Li from alloys of Al- Li and Li- Al using engineered scavenger compounds

Science.gov (United States)

Riley, W. D.; Jong, B. W.; Collins, W. K.; Gerdemann, S. J.

1994-01-01

A method of producing lithium of high purity from lithium aluminum alloys using an engineered scavenger compound, comprising: I) preparing an engineered scavenger compound by: a) mixing and heating compounds of TiO2 and Li2CO3 at a temperature sufficient to dry the compounds and convert Li.sub.2 CO.sub.3 to Li.sub.2 O; and b) mixing and heating the compounds at a temperature sufficient to produce a scavenger Li.sub.2 O.3TiO.sub.2 compound; II) loading the scavenger into one of two electrode baskets in a three electrode cell reactor and placing an Al-Li alloy in a second electrode basket of the three electrode cell reactor; III) heating the cell to a temperature sufficient to enable a mixture of KCl-LiCl contained in a crucible in the cell to reach its melting point and become a molten bath; IV) immersing the baskets in the bath until an electrical connection is made between the baskets to charge the scavenger compound with Li until there is an initial current and voltage followed by a fall off ending current and voltage; and V) making a connection between the basket electrode containing engineered scavenger compound and a steel rod electrode disposed between the basket electrodes and applying a current to cause Li to leave the scavenger compound and become electrodeposited on the steel rod electrode.

All-MXene-Based Integrated Electrode Constructed by Ti3C2 Nanoribbon Framework Host and Nanosheet Interlayer for High-Energy-Density Li-S Batteries.

Science.gov (United States)

Dong, Yanfeng; Zheng, Shuanghao; Qin, Jieqiong; Zhao, Xuejun; Shi, Haodong; Wang, Xiaohui; Chen, Jian; Wu, Zhong-Shuai

2018-03-27

High-energy-density lithium-sulfur (Li-S) batteries hold promise for next-generation portable electronic devices, but are facing great challenges in rational construction of high-performance flexible electrodes and innovative cell configurations for actual applications. Here we demonstrated an all-MXene-based flexible and integrated sulfur cathode, enabled by three-dimensional alkalized Ti 3 C 2 MXene nanoribbon (a-Ti 3 C 2 MNR) frameworks as a S/polysulfides host (a-Ti 3 C 2 -S) and two-dimensional delaminated Ti 3 C 2 MXene (d-Ti 3 C 2 ) nanosheets as interlayer on a polypropylene (PP) separator, for high-energy and long-cycle Li-S batteries. Notably, an a-Ti 3 C 2 MNR framework with open interconnected macropores and an exposed surface area guarantees high S loading and fast ionic diffusion for prompt lithiation/delithiation kinetics, and the 2D d-Ti 3 C 2 MXene interlayer remarkably prevents the shuttle effect of lithium polysulfides via both chemical absorption and physical blocking. As a result, the integrated a-Ti 3 C 2 -S/d-Ti 3 C 2 /PP electrode was directly used for Li-S batteries, without the requirement of a metal current collector, and exhibited a high reversible capacity of 1062 mAh g -1 at 0.2 C and enhanced capacity of 632 mAh g -1 after 50 cycles at 0.5 C, outperforming the a-Ti 3 C 2 -S/PP electrode (547 mAh g -1 ) and conventional a-Ti 3 C 2 -S on an Al current collector (a-Ti 3 C 2 -S/Al) (597 mAh g -1 ). Furthermore, the all-MXene-based integrated cathode displayed outstanding rate capacity of 288 mAh g -1 at 10 C and long-life cyclability. Therefore, this proposed strategy of constructing an all-MXene-based cathode can be readily extended to assemble a large number of MXene-derived materials, from a group of 60+ MAX phases, for applications such as various batteries and supercapacitors.

Lin28a regulates germ cell pool size and fertility

Science.gov (United States)

Shinoda, Gen; de Soysa, T. Yvanka; Seligson, Marc T.; Yabuuchi, Akiko; Fujiwara, Yuko; Huang, Pei Yi; Hagan, John P.; Gregory, Richard I.; Moss, Eric G.; Daley, George Q.

2013-01-01

Overexpression of LIN28A is associated with human germ cell tumors and promotes primordial germ cell (PGC) development from embryonic stem cells in vitro and in chimeric mice. Knockdown of Lin28a inhibits PGC development in vitro, but how constitutional Lin28a deficiency affects the mammalian reproductive system in vivo remains unknown. Here, we generated Lin28a knockout (KO) mice and found that Lin28a deficiency compromises the size of the germ cell pool in both males and females by affecting PGC proliferation during embryogenesis. Interestingly however, in Lin28a KO males the germ cell pool partially recovers during postnatal expansion, while fertility remains impaired in both males and females mated to wild type mice. Embryonic overexpression of let-7, a microRNA negatively regulated by Lin28a, reduces the germ cell pool, corroborating the role of the Lin28a/let-7 axis in regulating the germ lineage. PMID:23378032

Design and research on the measurement platform of the effective thermal conductivity for Li{sub 4}SiO{sub 4} and Li{sub 2}TiO{sub 3} pebble bed

Energy Technology Data Exchange (ETDEWEB)

Li, Yuanjie, E-mail: yuanjli@ustc.edu.cn; Yang, Wanli; Jin, Cheng; Zhao, Pinghui; Chen, Hongli

2015-10-15

China is carrying out the conceptual design of Chinese Fusion Engineering Testing Reactor (CFETR), and the Helium Cooled Pebble Bed (HCPB) blanket concept is one of the main choices for tritium production. Li{sub 4}SiO{sub 4} and Li{sub 2}TiO{sub 3} are the candidate breeder materials for the HCPB blanket concept. In the HCPB blanket, breeding pebbles with the diameter range of 0.6–1.2 mm are placed between two plates and the bed shall be cooled. Accordingly, effective thermal conductivity of pebble beds needs to be determined for the heat transfer calculation. Measurements of the heat transfer parameters of Li{sub 4}SiO{sub 4} and Li{sub 2}TiO{sub 3} pebble beds are being performed at the University of Science and Technology of China (USTC). Two measurement methods are being used. One is the steady state method with the use of thermocouples to measure the temperature distribution of the pebble bed. Another is transient thermal probe method using the temperature variation of the thermal probe and Monte Carlo inversion method to calculate the heat transfer parameters of the pebble bed. This paper will report on the progress of these measurement platforms.

Investigation of LiF, Mg and Ti (TLD-100) Reproducibility.

Science.gov (United States)

Sadeghi, M; Sina, S; Faghihi, R

2015-12-01

LiF, Mg and Ti cubical TLD chips (known as TLD-100) are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy) with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC) were obtained 4 times by irradiating them to doses of 81 mGy (two times), 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%.

Temperature compensation effects of TiO2 on Ca[(Li1/3Nb2/3)0.8Sn0.2]O3-δ microwave dielectric ceramic

Science.gov (United States)

Hu, Mingzhe; Wei, Huanghe; Xiao, Lihua; Zhang, Kesheng; Hao, Yongde

2017-10-01

The crystal structure and dielectric properties of TiO2-modified Ca[(Li1/3Nb2/3)0.8Sn0.2]O3-δ microwave ceramics are investigated in the present paper. The crystal structure is probed by XRD patterns and their Rietveld refinement, results show that a single perovskite phase is formed in TiO2-modified Ca[(Li1/3Nb2/3)0.8Sn0.2]O3-δ ceramics with the crystal structure belonging to the orthorhombic Pbnm 62 space group. Raman spectra results indicate that the B-site order-disorder structure transition is a key point to the dielectric loss of TiO2-modified Ca[(Li1/3Nb2/3)0.8Sn0.2]O3-δ ceramics at microwave frequencies. After properly modified by TiO2, the large negative temperature coefficient of Ca[(Li1/3Nb2/3)0.8Sn0.2]O3-δ ceramic can be compensated and the optimal microwave dielectric properties can reach 𝜀r = 25.66, Qf = 18,894 GHz and TCF = -6.3 ppm/∘C when sintered at 1170∘C for 2.5 h, which manifests itself for potential use in microwave dielectric devices for modern wireless communication.

Embedding nano-Li{sub 4}Ti{sub 5}O{sub 12} in hierarchical porous carbon matrixes derived from water soluble polymers for ultra-fast lithium ion batteries anodic materials

Energy Technology Data Exchange (ETDEWEB)

Lan, Chun-Kai; Bao, Qi; Huang, Yao-Hui; Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw

2016-07-15

Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites are successfully prepared by a facile and fast polymers assisted sol–gel method, aiming to promote both electronic and ionic conductivity. As indicated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis, three less expensive cost and available water soluble polymers (e.g. PAA, CMC, and SA) can homogeneously react with Li–Ti–O precursor to incorporate into interior of nano-scale lithium titanate and provide a continues conductive network after pyrolysis. In addition, the results of scanning electron microscopy and transmission electron microscopy also prove that the Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles are firmly embedded in porous carbon matrix with no obvious agglomeration. EIS measurement and cyclic voltammetry further reveal that the facilitated electrode kinetics and better ionic transport of Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites than that of Li{sub 4}Ti{sub 5}O{sub 12}. The c-CMC-LTO exhibits a superior capacity of 92 mAh g{sup −1} and retains its initial value with no obviously capacity decay over 200 cycles under an ultra-high C rate (50 C). - Graphical abstract: Schematic illustrations of the formation process of embedding LTO into Carbon matrixes derived from water soluable polymers (upper) and the electrochemical reaction paths in LTO/Carbon composites during charging/discharging processes (lower). - Highlights: • Hierarchical porous carbon matrixes were used to improve the Li{sub 4}Ti{sub 5}O{sub 12} anodes. • Carbon matrixes could suppress the agglomeration of Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles. • meso-nanoporous carbon structure was beneficial for filtration of electrolyte. • The c-CMC-LTO exhibited superior high rate capability and cycling durability.

Study of the response reduction of LiF:Mg, Ti dosimeter for high dose dosimetry

Energy Technology Data Exchange (ETDEWEB)

Torkzadeh, Falamarz [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Applications Research School; AEOI, Tehran (Iran, Islamic Republic of); Faripour, Heidar [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Laser and Optics Research School; AEOI, Tehran (Iran, Islamic Republic of); Mardashti, Forough; Manouchehri, Farhad [Nuclear Sciences and Technology Research Institute, Tehran (Iran, Islamic Republic of). Radiation Applications Research School

2017-07-15

A single crystal and 5 polycrystalline samples of LiF:Mg, Ti and their pellets were prepared and investigated so as to apply thermoluminescence high gamma dose dosimetry. Three zones of single crystal with dopant concentrations of 200 ppm of Mg and 20 ppm of Ti were also used to prepare the single crystal samples. For polycrystalline samples, dopant concentrations of 0.062 mol% Mg and Ti concentrations in the range of 0.016 and 0.046 mol% were used. All the samples were exposed to gamma doses of 1 kGy to 700 kGy and their response changes were determined by a gamma dose test of about 60 mGy. According to the results obtained, the use of response reduction by curve-fitting up to about 300 kGy can be performed reliably for high dose gamma dosimetry.

Ultrathin Li4Ti5O12 nanosheets as anode materials for lithium and sodium storage

Energy Technology Data Exchange (ETDEWEB)

Feng, Xuyong; Zou, Hailin; Xiang, Hongfa; Guo, Xin; Zhou, Tianpei; Wu, Yucheng; Xu, Wu; Yan, Pengfei; Wang, Chong M.; Zhang, Jiguang; Yu, Yan

2016-06-13

Two-dimensional Li4Ti5O12 (LTO) nanosheets are prepared via a surfactant assisted hydrothermal process. Polyether (P123) was added as the surfactant to modify the surface and control the microstructure of the hydrothermal products and thus affect the electrochemical performance of the as-synthesized LTO anode material. XRD results show that the addition of P123 can restrain the growth of Li2TiO3 during the hydrothermal process, thus affecting the morphology and enhancing the rate performance of the final products. With the addition of P123, the growth of LTO can be restrained and ultrathin LTO nanosheets can be obtained after high temperature sintering, which is beneficial for the charge transfer and Li+ ion diffusion. The rate performance of these two different LTO materials is very different because of their differences in phase composition and fine morphology. The P123-assisted nanostructured LTO sample (P-LTO) shows a much higher rate capability than the LTO sample without P123, with over 130 mAh g-1 capacity retained at the charge-discharge rate of 64C when used in a lithium battery. For intercalation of larger size Na+ ions, the P-LTO still exhibit a capacity of 115 mAh g-1 at a charge (de-sodiation process) rate of 10C and maintains 96% capacity after 400 cycles

Thermoluminescence of LiNaSo4: TI after exposure to radiation doses from electrons of different energies

International Nuclear Information System (INIS)

El-Kolaly, M.A.

2002-01-01

Lithium sodium sulphate doped by rare impurities (LiNaSO 4 : TI) has been locally prepared. Its Thermoluminescence properties (TL) have been performed from room temperature up to 300 degree C. The used heating rate was 5 degree C/sec. The samples were irradiated by electrons of different energies (5, 7, 9 and 13 MeV.). These samples were exposed to different duration to attain different radiation doses. It has been observed that the glow curves are consisted of four glow peaks at 75, 125, 225 and 250 degree C respectively. The first peak showed a linear dependence with electron radiation doses and can be used in radiation measurement. The irradiated impurities LiNaSO 4 : TI with energies higher than 5 MeV showed no appreciable change in the TL peak height. The obtained results will explore the probability of using such system (double sulphates doped by rare earth impurities) in the field of radiation measurements

N-doped hollow urchin-like anatase TiO2@C composite as a novel anode for Li-ion batteries

Science.gov (United States)

Xing, Yalan; Wang, Shengbin; Fang, Baizeng; Song, Ge; Wilkinson, David P.; Zhang, Shichao

2018-05-01

N-doped hollow urchin-like anatase TiO2 spheres (HUTSs) with carbon coating (HUTS@C) are prepared through a facile and scalable hydrothermal reaction followed by coating of polypyrrole and carbonization. The HUTS is composed of radially grown anatase nanorods and possesses an enhanced percentage of exposed {001} facets compared with P25 TiO2 nanoparticles. After the carbon coating, the HUTS@C retains the hollow nanostructure although covered with an N-doped carbon layer. As an anode for Li-ion batteries, the HUTS@C delivers a higher capacity of 165.1 mAh g-1 at 1C after 200 cycles and better rate capability (111.7 mAh g-1 at 10C) than the HUTS. Further electrochemical studies reveal that the HUTS@C has a better electrochemical reversibility, lower charge-transfer resistance, and higher Li-ion diffusion coefficient due to its unique nanosctructure including the hollow core, anatase phase of TiO2 microspheres with high exposed {001} facets and the N-doped carbon layer, which facilitates mass transport and enhances electrical conductivity.

Novel peapoded Li4Ti5O12 nanoparticles for high-rate and ultralong-life rechargeable lithium ion batteries at room and lower temperatures

Science.gov (United States)

Peng, Liang; Zhang, Huijuan; Fang, Ling; Zhang, Yan; Wang, Yu

2016-01-01

In this paper, a novel peapod-like Li4Ti5O12-C composite architecture with high conductivity is firstly designed and synthesized to be used as anode materials for lithium-ion batteries. In the synthesis, Na2Ti3O7 nanotubes act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source, thus the peapod-like Li4Ti5O12-C composite can be fabricated by a facile hydrothermal reaction and the subsequent solid-state process. Compared to the previous reports, the as-prepared samples obtained by our new strategy exhibit excellent electrochemical performances, such as outstanding rate capability (an extremely reversible capability of 148 mA h g-1, 125 mA h g-1 at 30 C and 90 C, respectively) as well as excellent cycling performance (about 5% capacity loss after 5000 cycles at 10 C with 152 mA h g-1 capacity retained). The low-temperature measurements also demonstrate that the electrochemical performances of the peapod-like Li4Ti5O12-C composite are remarkably improved at various rate currents (at the low-temperature of -25 °C, a high Coulombic efficiency of about 99% can be achieved after 500 cycles at 10 C).In this paper, a novel peapod-like Li4Ti5O12-C composite architecture with high conductivity is firstly designed and synthesized to be used as anode materials for lithium-ion batteries. In the synthesis, Na2Ti3O7 nanotubes act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source, thus the peapod-like Li4Ti5O12-C composite can be fabricated by a facile hydrothermal reaction and the subsequent solid-state process. Compared to the previous reports, the as-prepared samples obtained by our new strategy exhibit excellent electrochemical performances, such as outstanding rate capability (an extremely reversible capability of 148 mA h g-1, 125 mA h g-1 at 30 C and 90 C, respectively) as well as excellent cycling performance (about 5% capacity loss after 5000 cycles at 10 C with 152 mA h g-1 capacity

Ceramic thick film humidity sensor based on MgTiO{sub 3} + LiF

Energy Technology Data Exchange (ETDEWEB)

Kassas, Ahmad, E-mail: a.kassas.mcema@ul.edu.lb [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Bernard, Jérôme; Lelièvre, Céline; Besq, Anthony; Guhel, Yannick; Houivet, David; Boudart, Bertrand [Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Lakiss, Hassan [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Faculty of Engineering, Section III, Hariri Campus, Hadath, Beirut (Lebanon); Hamieh, Tayssir [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon)

2013-10-15

Graphical abstract: - Highlights: • The fabricated sensor based on MgTiO{sub 3} + LiF materials used the spin coating technology. • The response time is 70 s to detect variation between 5 and 95% relative humidity. • The addition of Scleroglucan controls the viscosity and decreases the roughness of thick film surface. • This humidity sensor is a promising, low-cost, high-quality, reliable ceramic films, that is highly sensitive to humidity. - Abstract: The feasibility of humidity sensor, consisting of a thick layer of MgTiO{sub 3}/LiF materials on alumina substrate, was studied. The thermal analysis TGA-DTGA and dilatometric analysis worked out to confirm the sintering temperature. An experimental plan was applied to describe the effects of different parameters in the development of the thick film sensor. Structural and microstructural characterizations of the developed thick film were made. Rheological study with different amounts of a thickener (scleroglucan “sclg”), showing the behavior variation, as a function of sclg weight % was illustrated and rapprochement with the results of thickness variation as a function of angular velocity applied in the spin coater. The electrical and dielectric measurements confirmed the sensitivity of the elaborated thick film against moisture, along with low response time.

Spinel Li2CoTi3O8 nanometer obtained for application as pigment

International Nuclear Information System (INIS)

Costa de Camara, M. S.; Alves Pimentel, L.; Longo, E.; Nobrega Azevedo, L. da; Araujo Melo, D. M. de

2016-01-01

Pigments are used in ceramics, cosmetics, inks, and other applications widely materials. To this must be single and easily reproducible. Moreover, the pigments obtained in the nanoscale are more stable, reproducible and highlight color in small amounts compared with those obtained in micrometer scale. The mixed oxides with spinel structures AB 2 O 4 have important applications, including: pigments, refractories, catalytic and electronic ceramics. In this context, the aim of this work was the preparation of powder Li 2 CoTi 3 O 8 spinel phase with nanometer particle size of the polymeric precursor method (Pechini) and characterization by means of thermal analysis (TG/DTA) X-ray diffraction (XRD), refined by the Rietveld method, BET, transmission electron microscopy (TEM), Raman and colorimetric coordinates. The pigment was obtained by heat treatment of 400 degree centigrade to 1000 degree centigrade after pyrolysis at 300 degree centigrade/1 h for removing the organic material. Li 2 CoTi 3 O 8 desired spinel phase was obtained from 500 degree centigrade, and presenting stability nanometer to about 1.300 degree centigrade. Spinel green phase introduced at temperatures in the range of 400 degree centigrade and 500 degree centigrade, and 600 degree centigrade at temperatures between blue and 1000 degree centigrade. (Author)

Dose Measurements in a Phantom Simulating Neonates by Using Different TL Materials: LiF:Mg,Cu,P and LiF:Mg,Ti

International Nuclear Information System (INIS)

Saez-Vergara, J.C.; Romero, A.M.; Fernandez, C.; Gomez, S.; Vazquez, J.; Olivares, M.P.

1999-01-01

A study reproducing usual exposure conditions in a special care baby unit has been performed to measure doses using TL materials in a versatile phantom specially designed for neonates having X ray examinations. The phantom offers the possibilities of reproducing different patient thicknesses and representing either a solid or hollow lung region. The results of the dose measurements using TL materials at the entrance, exit and both laterals of the phantom during different chest radiograph conditions are presented. Test conditions were reproduced in both hollow and solid chest cages simulating patient thicknesses of 5, 6 and 7 cm. The study was completed using two types of TL materials, LiF:Mg,Cu,P and LiF:Mg,Ti, in order to analyse and correct the differences on energy response between the two phosphors. (author)

The Lin28/let-7 axis regulates glucose metabolism

Science.gov (United States)

Zhu, Hao; Shyh-Chang, Ng; Segrè, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

2012-01-01

SUMMARY The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by blocking let-7 biogenesis. In studies of the Lin28/let-7 pathway, we discovered unexpected roles in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promoted an insulin-sensitized state that resisted high fat diet-induced diabetes, whereas muscle-specific loss of Lin28a and overexpression of let-7 resulted in insulin resistance and impaired glucose tolerance. These phenomena occurred in part through let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. The mTOR inhibitor rapamycin abrogated the enhanced glucose uptake and insulin-sensitivity conferred by Lin28a in vitro and in vivo. In addition, we found that let-7 targets were enriched for genes that contain SNPs associated with type 2 diabetes and fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism. PMID:21962509

Espinela Li2CoTi3O8 nanométrica obtenida para aplicación como pigmento

Directory of Open Access Journals (Sweden)

Maria Suely Costa da Câmara

2016-03-01

En este contexto, el objetivo de este trabajo fue la preparación de polvo de la fase espinela Li2CoTi3O8 con tamaño de partícula nanométrica por el método de los precursores poliméricos (Pechini y caracterización por medio de las técnicas de análisis térmico (TG/DTA, difracción de rayos X (DRX, refinamiento por el método de Rietveld, BET, microscopia electrónica de transmisión (TEM, Raman y coordenadas colorimétricas. El pigmento fue obtenido por tratamientos térmicos de 400 a 1.000 °C después de su pirólisis a 300 °C/1 h para la eliminación del material orgánico. La fase espinela Li2CoTi3O8 deseada fue obtenida a partir de 500 °C, nanométrica y presentando estabilidad hasta aproximadamente 1.300 °C. La fase espinela presentó el color verde a temperaturas en el rango de 400-500 °C y azul a temperaturas entre 600 y 1.000 °C. Por lo tanto, los resultados demuestran la viabilidad de utilización de esta fase espinela Li2CoTi3O8 como pigmento, ya que presentó coloración a baja temperatura y con partícula nanométrica.

Synthesis of TiC Nanoparticles Anchored on Hollow Carbon Nanospheres for Enhanced Polysulfide Adsorption in Li-S Batteries.

Science.gov (United States)

Cao, Bokai; Chen, Yong; Li, De; Yin, Lihong; Mo, Yan

2016-12-08

A novel spatial confinement strategy based on a carbon/TiO 2 /carbon sandwich structure is proposed to synthesize TiC nanoparticles anchored on hollow carbon nanospheres (TiC@C) through a carbothermal reduction reaction. During the synthesis process, two carbon layers not only serve as reductant to convert TiO 2 into TiC nanoparticles, but also create a spatial confinement to suppress the aggregation of TiO 2 , resulting in the formation of well-dispersed TiC nanoparticles. This unique TiC@C structure shows an outstanding long-term cycling stability at high rates owing to the strong physical and chemical adsorption of lithium polysulfides (i.e., a high capacity of 732.6 mA h g -1 at 1600 mA g -1 ) and it retains a capacity of 443.2 mA h g -1 after 1000 cycles, corresponding to a decay rate of only 0.0395 % per cycle. Therefore, this unique TiC@C composite could be considered as an important candidate for the cathode material in Li-S batteries. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoluminescence characteristics of Li-doped CaTiO{sub 3}:Pr{sup 3+} thin films grown on Si (100) substrate by PLD

Energy Technology Data Exchange (ETDEWEB)

Yang, Hyun Kyoung; Chung, Jong Won; Moon, Byung Kee; Choi, Byung Chun [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Jeong, Jung Hyun, E-mail: jhjeong@pknu.ac.k [Department of Physics, Pukyong National University, Busan 608-737 (Korea, Republic of); Jang, Ki-wan; Lee, Ho Sueb [Department of Physics, Changwon National University, Changwon 641-773 (Korea, Republic of); Yi, Soung Soo [Department of Electronic Materials Engineering, Silla University, Busan, 617-736 (Korea, Republic of); Kim, Kwang Ho [School of Materials Science and Engineering, Pusan National University, Busan, 609-735 (Korea, Republic of)

2010-09-01

The effects of Li-doped CaTiO{sub 3}:Pr{sup 3+} thin films have been investigated by varying the lithium ion concentrations from 0 to 5 wt.%. The films have been deposited on Si (100) substrate using a pulsed laser deposition technique. Structural properties of these films have been studied by the measurement of their XRD, SEM, and AFM. The variation of Li{sup +} concentration influences the crystallinity and surface morphology of the CaTiO{sub 3}:Pr{sup 3+} thin films. As Li{sup +} content increases from 0 to 1 wt.%, the crystallinity and intensity of emission increases. The dominant emission is from {sup 1}D{sub 2} {yields} {sup 3}H{sub 4} transition at 613 nm. The {sup 1}D{sub 2} emission quenching has also been observed in highly doped sample and is related to the cross-relaxation process between Pr{sup 3+} ions.

Investigation of LiF, Mg and Ti (TLD-100 Reproducibility

Directory of Open Access Journals (Sweden)

Sadeghi M.

2015-12-01

Full Text Available LiF, Mg and Ti cubical TLD chips (known as TLD-100 are widely used for dosimetry purposes. The repeatability of TL dosimetry is investigated by exposing them to doses of (81, 162 and 40.5 mGy with 662keV photons of Cs-137. A group of 40 cubical TLD chips was randomly selected from a batch and the values of Element Correction Coefficient (ECC were obtained 4 times by irradiating them to doses of 81 mGy (two times, 162mGy and 40.5mGy. Results of this study indicate that the average reproducibility of ECC calculation for 40 TLDs is 1.5%, while these values for all chips do not exceed 5%.

Three-body Coulomb breakup of 11Li in the complex scaling method

International Nuclear Information System (INIS)

Myo, Takayuki; Aoyama, Shigeyoshi; Kato, Kiyoshi; Ikeda, Kiyomi

2003-01-01

Coulomb breakup strengths of 11 Li into a three-body 9 Li+n+n system are studied in the complex scaling method. We decompose the transition strengths into the contributions from three-body resonances, two-body '' 10 Li+n'' and three-body '' 9 Li+n+n'' continuum states. In the calculated results, we cannot find the dipole resonances with a sharp decay width in 11 Li. There is a low energy enhancement in the breakup strength, which is produced by both the two- and three-body continuum states. The enhancement given by the three-body continuum states is found to have a strong connection to the halo structure of 11 Li. The calculated breakup strength distribution is compared with the experimental data from MSU, RIKEN and GSI

A Quasi-Solid-State Li-Ion Capacitor Based on Porous TiO2 Hollow Microspheres Wrapped with Graphene Nanosheets.

Science.gov (United States)

Wang, Faxing; Wang, Chun; Zhao, Yujuan; Liu, Zaichun; Chang, Zheng; Fu, Lijun; Zhu, Yusong; Wu, Yuping; Zhao, Dongyuan

2016-12-01

The quasi-solid-state Li-ion capacitor is demonstrated with graphene nanosheets prepared by an electrochemical exfoliation as the positive electrode and the porous TiO 2 hollow microspheres wrapped with the same graphene nanosheets as the negative electrode, using a Li-ion conducting gel polymer electrolyte. This device may be the key to bridging the gap between conventional lithium-ion batteries and supercapacitors, meanwhile meeting the safety demands of electronic devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Refinements to calandria tube - liquid injection nozzle (CT-LIN) contact assessments

International Nuclear Information System (INIS)

Sedran, P.J.

2012-01-01

In recent years, the issue of CT-LIN contact, which first gained attention in 1989, has been addressed through CT-LIN gap measurements, followed by analytical predictions of time-to-contact. CT-LIN time-to-contact predictions have been preformed independently by CPUS Limited for Point Lepreau and Gentilly-2 and by AECL Sheridan Park (now Candu Energy Inc.) for Bruce Power and Gentilly-2. Both companies used the CDEPTH code in combination with CT-LIN gap measurements. Subsequent to the assessments for Point Lepreau and Gentilly-2, a recommended approach for future assessments was presented at the 2008 CANDU maintenance conference. Since that time, a number of refinements to the overall strategy for predicting CT-LIN time-to-contact have been developed and are outlined in this paper. The refinements include: 1. The use of ultrasonic LIN elevation measurements to confirm LIN creep sag behaviour 2. The development of a non-linear empirical CT Creep Sag Model 3. The development of a rationale for discrepancies observed in repeated optical CT-LIN gap measurements and a discussion of alternative CT-LIN gap measurements With these refinements, more accurate CT-LIN time-to-contact predictions can be obtained. For stations that plan to refurbish by 210,000 EFPH, the improvement in time-to-contact predictions resulting from the fore mentioned refinements will not be of any real benefit.. However, for stations that are planning life extensions in order to operate beyond 210,000 EFPH, CT-LIN contact will be an issue. For these stations, improvements in CT-LIN contact time predictions would be beneficial. This paper presents a summary of the proposed refinements and demonstrates how they would impact CT-LIN time-to-contact predictions. (author)

Graphene oxide-confined synthesis of Li4Ti5O12 microspheres as high-performance anodes for lithium ion batteries

International Nuclear Information System (INIS)

Zhang, Jiawei; Cai, Yurong; Wu, Jun; Yao, Juming

2015-01-01

This paper reports a graphene oxide (GO) confined strategy to synthesize reduced GO-coated lithium titanate (Li 4 Ti 5 O 12, LTO) microspheres using as-prepared TiO 2 microspheres and GO as raw materials. The obtained samples are characterized by X-ray diffraction, field emission scanning electron microscopy and spectrophotometer. Results show that the spherical LTO is formed with approximate 1 μm diameter after hydrothermal reactions, which is due to a confined effect of GO on the surface of TiO 2 spheres. Electrochemical tests reveal that the presence of rGO can increase the capacity and cycling stability of LTO anodes, especially at higher C rate. The 3 wt% rGO-coated LTO anodes present a higher reversible Li-ion storage with a specific discharge capacity of 131.6 mAh g −1 at 5 C and 97% retention even after 500 cycles, which are more excellent than those of pristine LTO. The GO-confined method is anticipated to synthesize other electrode materials with high electrochemical performances

Spinel Li{sub 2}CoTi{sub 3}O{sub 8} nanometer obtained for application as pigment; Espinela Li{sub 2}CoTi{sub 3}O{sub 8} nanometrica obtenida para aplicacion como pigmento

Energy Technology Data Exchange (ETDEWEB)

Costa de Camara, M. S.; Alves Pimentel, L.; Longo, E.; Nobrega Azevedo, L. da; Araujo Melo, D. M. de

2016-05-01

Pigments are used in ceramics, cosmetics, inks, and other applications widely materials. To this must be single and easily reproducible. Moreover, the pigments obtained in the nanoscale are more stable, reproducible and highlight color in small amounts compared with those obtained in micrometer scale. The mixed oxides with spinel structures AB{sub 2}O{sub 4} have important applications, including: pigments, refractories, catalytic and electronic ceramics. In this context, the aim of this work was the preparation of powder Li{sub 2}CoTi{sub 3}O{sub 8} spinel phase with nanometer particle size of the polymeric precursor method (Pechini) and characterization by means of thermal analysis (TG/DTA) X-ray diffraction (XRD), refined by the Rietveld method, BET, transmission electron microscopy (TEM), Raman and colorimetric coordinates. The pigment was obtained by heat treatment of 400 degree centigrade to 1000 degree centigrade after pyrolysis at 300 degree centigrade/1 h for removing the organic material. Li{sub 2}CoTi{sub 3}O{sub 8} desired spinel phase was obtained from 500 degree centigrade, and presenting stability nanometer to about 1.300 degree centigrade. Spinel green phase introduced at temperatures in the range of 400 degree centigrade and 500 degree centigrade, and 600 degree centigrade at temperatures between blue and 1000 degree centigrade. (Author)

Characteristics of new LiF preparations and sensitised LiF

Energy Technology Data Exchange (ETDEWEB)

Driscoll, C M.H.; O' Hagan, J B; Mundy, S J; Todd, C D; McWhan, A F; Dodson, J

1986-01-01

The patent governing the preparation and production of lithium fluoride (LiF) awarded to the Harshaw Chemical Co. has expired. Other companies have become interested in developing additional preparations of this material. Two of these preparations include LiF:Mg,Ti manufactured by Vinten Instruments plc and high sensitivity LiF:Mg, Cu,P distributed by them. The properties of these materials, including sensitivity, dose threshold, photon energy response, reusability and storage characteristics, are presented in this paper and compared with those of Harshaw TLD-100 and with those of sensitised LiF.

High temperature reactivity of Li-titanates with H2 contained in Ar purge

International Nuclear Information System (INIS)

Alvani, C.; Casadio, S.; Contini, V.; Giorgi, R.; Mancini, M.R.; Pierdominici, F.; Salernitano, E.; Tsuchiya, Kunihiko; Kawamura, Hiroshi

2004-01-01

The reduction of stoichiometric and Li-depleted Li 2 TiO 3 (Li-Ti) pebbles was studied by isothermal step-annealing at 900degC in Ar + 0.1%H 2 sweep gas (R-gas, TPR cycle) followed by their re-oxidation (TPO ramps) performed in O 2 and in H 2 O vapor doped inert gases. The pebbles were found to react by a complex process whose characteristics (reaction rate and reduction degree) seem to depend mainly on the compound Li-depletion degree. When the depletion degree is high a new phase could be observed to nucleate at their grain surfaces. A fine powder of Li 4 Ti 5 O 12 spinel oxide was also studied by TPR/TPO and by Thermo-analysis. Under reduction at 1000degC in flowing Ar + 3%H 2 gas the spinel powder was found to react decomposing into orthorhombic Li 0.14 TiO 2 phase and Li 2 O. TG-DTA patterns were consistent with the relative TPR/TPO spectra, including those performed on the Li-Ti pebbles. The high temperature reduction rate and degree of these materials were then assumed to depend on their spinel phase content which decomposes with nucleation of orthorhombic type Li x TiO 2 phases (with 0.14 ≤ x < 0.45) at the Li-depleted grain boundary surfaces. (author)

Nanostructured Networks for Energy Storage: Vertically Aligned Carbon Nanotubes (VACNT as Current Collectors for High-Power Li4Ti5O12(LTO//LiMn2O4(LMO Lithium-Ion Batteries

Directory of Open Access Journals (Sweden)

Fabian Pawlitzek

2017-11-01

Full Text Available As a concept for electrode architecture in high power lithium ion batteries, self-supported nanoarrays enable ultra-high power densities as a result of their open pore geometry, which results in short and direct Li+-ion and electron pathways. Vertically aligned carbon nanotubes (VACNT on metallic current collectors with low interface resistance are used as current collectors for the chemical solution infiltration of electroactive oxides to produce vertically aligned carbon nanotubes decorated with in situ grown LiMn2O4 (LMO and Li4Ti5O12 (LTO nanoparticles. The production processes steps (catalyst coating, VACNT chemical vapor deposition (CVD, infiltration, and thermal transformation are all scalable, continuous, and suitable for niche market production to achieve high oxide loadings up to 70 wt %. Due to their unique transport structure, as-prepared nanoarrays achieve remarkably high power densities up to 2.58 kW kg−1, which is based on the total electrode mass at 80 C for LiMn2O4//Li4Ti5O12 full cells. The tailoring of LTO and LMO nanoparticle size (~20–100 nm and VACNT length (array height: 60–200 µm gives insights into the rate-limiting steps at high current for these kinds of nanoarray electrodes at very high C-rates of up to 200 C. The results reveal the critical structural parameters for achieving high power densities in VACNT nanoarray full cells.

The effect of TiB2 reinforcement on the mechanical properties of an Al-Cu-Li alloy-based metal-matrix composite

Science.gov (United States)

Langan, T. J.; Pickens, J. R.

1991-01-01

Weldalite 049, an Al-base Cu-Li-Mg-Ag-Zr alloy, achieves 700 MPa tensile strengths in the near-peak-aged temper in virtue of the nucleation of a T(1)-type platelike strengthening precipitate. Attention is presently given to the possibility that the alloy's modulus could be further increased through the addition of high-modulus TiB2 particles, using the 'XD' process, due to TiB2's good wettability with liquid Al. An 8-percent modulus increase is obtained with 4 vol pct TiB2.

Na insertion into nanocrystalline Li4Ti5O12 spinel: An electrochemical study

Czech Academy of Sciences Publication Activity Database

Zukalová, Markéta; Pitňa Lásková, Barbora; Klementová, Mariana; Kavan, Ladislav

2017-01-01

Roč. 245, AUG 2017 (2017), s. 505-511 ISSN 0013-4686 R&D Projects: GA ČR GA15-06511S; GA MŠk LM2015087 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Na insertion * Li4Ti5O12 * nanocrystalline Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D) Impact factor: 4.798, year: 2016

Lin28 sustains early renal progenitors and induces Wilms tumor

Science.gov (United States)

Urbach, Achia; Yermalovich, Alena; Zhang, Jin; Spina, Catherine S.; Zhu, Hao; Perez-Atayde, Antonio R.; Shukrun, Rachel; Charlton, Jocelyn; Sebire, Neil; Mifsud, William; Dekel, Benjamin; Pritchard-Jones, Kathy; Daley, George Q.

2014-01-01

Wilms Tumor, the most common pediatric kidney cancer, evolves from the failure of terminal differentiation of the embryonic kidney. Here we show that overexpression of the heterochronic regulator Lin28 during kidney development in mice markedly expands nephrogenic progenitors by blocking their final wave of differentiation, ultimately resulting in a pathology highly reminiscent of Wilms tumor. Using lineage-specific promoters to target Lin28 to specific cell types, we observed Wilms tumor only when Lin28 is aberrantly expressed in multiple derivatives of the intermediate mesoderm, implicating the cell of origin as a multipotential renal progenitor. We show that withdrawal of Lin28 expression reverts tumorigenesis and markedly expands the numbers of glomerulus-like structures and that tumor formation is suppressed by enforced expression of Let-7 microRNA. Finally, we demonstrate overexpression of the LIN28B paralog in a significant percentage of human Wilms tumor. Our data thus implicate the Lin28/Let-7 pathway in kidney development and tumorigenesis. PMID:24732380

Weak Activity of Haloalkane Dehalogenase LinB with 1,2,3-Trichloropropane Revealed by X-Ray Crystallography and Microcalorimetry▿

OpenAIRE

Monincová, Marta; Prokop, Zbyněk; Vévodová, Jitka; Nagata, Yuji; Damborský, Jiří

2007-01-01

1,2,3-Trichloropropane (TCP) is a highly toxic and recalcitrant compound. Haloalkane dehalogenases are bacterial enzymes that catalyze the cleavage of a carbon-halogen bond in a wide range of organic halogenated compounds. Haloalkane dehalogenase LinB from Sphingobium japonicum UT26 has, for a long time, been considered inactive with TCP, since the reaction cannot be easily detected by conventional analytical methods. Here we demonstrate detection of the weak activity (kcat = 0.005 s−1) of Li...

Photon and neutron energy response of Thermoluminescent (TL) dosimeters

International Nuclear Information System (INIS)

Thilagam, L.; Priya, M.R.; Mohapatra, D.K.

2018-01-01

Theoretical Monte Carlo (MC) simulations are carried out to investigate the relative thermoluminesence (TL) response of the most commonly used TLD materials to a wide range of photon energy. The effect of polytetrafluoroethylene (PTFE) on TL response of CaSO 4 :Dy is also studied. Additionally, the neutron response of LiF:Mg,Ti TL materials with different concentrations of 6 Li is estimated in terms of the number of 6 Li(n, t) 4 He capture reactions for a wider neutron energy

On the enhancement of Er{sup 3+} diffusion in LiNbO{sub 3} crystals by Er{sup 3+}/Ti{sup 4+} co-diffusion

Energy Technology Data Exchange (ETDEWEB)

Almeida, José Manuel Marques Martins de, E-mail: jmmma@utad.pt [INESC-TEC, Rua do Campo Alegre, 687, Porto 4169-007 (Portugal); Department of Physics, School of Science and Technology, University of Trás-os-Montes e Alto Douro, PO. Box 1013, 5001-801 Vila Real (Portugal); Sada, Cinzia [Dipartimento di Fisica e Astronomia G. Galilei, Università di Padova, Via Marzolo 8, 35131 Padova (Italy)

2016-02-15

Highlights: • Enhancement of the diffusion of erbium ions (Er{sup 3+}) in lithium niobate crystals. • Incoherence on published results lead to need for systematic revision of literature. • Further insight into the topic of co-diffusion of Er{sup 3+}/Ti{sup 4+} ions into LiNbO{sub 3}. - Abstract: After carrying out a revision of the literature on the enhancement of Er{sup 3+} diffusion in LiNbO{sub 3} crystals by Er{sup 3+}/Ti{sup 4+} co-diffusion and analyzing our own experimental results, we conclude that no reproducible results were reported, meaning that further research on this subject is necessary.

Effects of titanium incorporation on phase and electrochemical performance in LiFePO4 cathode material

International Nuclear Information System (INIS)

Wang Zhaohui; Pang Quanquan; Deng Kejian; Yuan Lixia; Huang Fei; Peng Yunlong; Huang Yunhui

2012-01-01

Highlights: ► Nominal LiFe 1−x Ti x PO 4 cathode materials were synthesized via solid-state reaction. ► A clear feature of Ti-doped LiFePO 4 has been clarified. ► The formation of impurity phases strongly depends on Ti doping level. ► Appropriate amount of Ti in LiFePO 4 can enhance the electrochemical performance. - Abstract: Ti-incorporated LiFe 1−x Ti x PO 4 (0 ≤ x ≤ 0.2) samples have been prepared via a two-step solid-state reaction route. The samples have systematically been investigated with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), cyclic voltammetry (CV) and charge/discharge measurements. The incorporation of Ti in LiFePO 4 significantly enhances the electrochemical performance; the carbon-coated LiFe 0.9 Ti 0.1 PO 4 sample shows the best performance. It is confirmed that LiFe 1−x Ti x PO 4 with x ≤ 0.05 are of single phase while those with 0.07 ≤ x ≤ 0.2 contain impurity phases: LiTi 2 (PO 4 ) 3 and TiP 2 O 7 . The impurities influence not only the electronic conductivity, but also the total specific capacity. Appropriate amount of titanium incorporation is favorable for the improvement in electrochemical performance.

The Formation of Lithiated Ti-Doped α-Fe2O3 Nanocrystalline Particles by Mechanical Milling of Ti-Doped Lithium Spinel Ferrite

International Nuclear Information System (INIS)

Widatallah, H. M.; Gismelseed, A. M.; Bouziane, K.; Berry, F. J.; Al Rawas, A. D.; Al-Omari, I. A.; Yousif, A. A.; Elzain, M. E.

2004-01-01

The milling of spinel-related Ti-doped Li 0.5 Fe 2.5 O 4 for different times is studied with XRD, Moessbauer spectroscopy and magnetic measurements. Milling converts the material to Li-Ti-doped α-Fe 2 O 3 nanocrystalline particles via an intermediate γ-LiFeO 2 -related phase. The role played by the dopant Ti-ion in the process is emphasized.

lin-12 Notch functions in the adult nervous system of C. elegans

Directory of Open Access Journals (Sweden)

Tucey Tim M

2005-07-01

Full Text Available Abstract Background Notch signaling pathways are conserved across species and traditionally have been implicated in cell fate determination during embryonic development. Notch signaling components are also expressed postdevelopmentally in the brains of adult mice and Drosophila. Recent studies suggest that Notch signaling may play a role in the physiological, rather than developmental, regulation of neurons. Here, we investigate a new non-developmental role for Caenorhabditis elegans lin-12 Notch signaling in neurons regulating the spontaneous reversal rate during locomotion. Results The spontaneous reversal rate of C. elegans during normal locomotion is constant. Both lin-12 gain and loss of function mutant animals had significantly increased reversal rates compared to wild type controls. These defects were caused by lin-12 activity, because the loss of function defect could be rescued by a wild type lin-12 transgene. Furthermore, overexpression of lin-12 recapitulated the gain-of-function defect. Increasing or decreasing lin-12 activity in the postdevelopmental adult animal was sufficient to rapidly and reversibly increase reversals, thereby excluding a developmental role for lin-12. Although lin-12 is expressed in the vulval and somatic gonad lineages, we find that these tissues play no role in regulating reversal rates. In contrast, altering lin-12 activity specifically in the nervous system was sufficient to increase reversals. These behavioral changes require components of the canonical lin-12 signaling cascade, including the ligand lag-2 and the transcriptional effector lag-1. Finally, the C. elegans AMPA/kainate glutamate receptor homolog glr-1 shows strong genetic interactions with lin-12, suggesting that glr-1 and/or other glutamate gated channels may be targets of lin-12 regulation. Conclusion Our results demonstrate a neuronal role for lin-12 Notch in C. elegans and suggest that lin-12 acutely regulates neuronal physiology to

Luminescent emission of LiF: Mg, Ti exposed to UV radiation

International Nuclear Information System (INIS)

Estrada G, A.; Castano M, V.M.; Cruz Z, E.; Garcia F, F.

2002-01-01

It was investigated the luminescent emission stimulated by heat (Tl) of LiF: Mg, Ti crystals which were exposed to UV radiation coming from a mercury lamp. Since this crystal depends on the thermal history, it has been used a thermal treatment consisting of a baking at 380 C during one hour for each reading and they were irradiated with UV. The brilliance curves between 5 and 840 minutes of exposure in the face of UV light were obtained. An important loss in the response, starting from 150 minutes of irradiation was observed. Also the relative intensity of the brilliance curve decay when the crystals being stored in darkness and room temperature conditions, which is according to the results in the literature about. (Author)

Li7(BH)5(+): a new thermodynamically favored star-shaped molecule.

Science.gov (United States)

Torres-Vega, Juan J; Vásquez-Espinal, Alejandro; Beltran, Maria J; Ruiz, Lina; Islas, Rafael; Tiznado, William

2015-07-15

The potential energy surfaces (PESs) of Lin(BH)5(n-6) systems (where n = 5, 6, and 7) were explored using the gradient embedded genetic algorithm (GEGA) program, in order to find their global minima conformations. This search predicts that the lowest-energy isomers of Li6(BH)5 and Li7(BH)5(+) contain a (BH)5(6-) pentagonal fragment, which is isoelectronic and structurally analogous to the prototypical aromatic hydrocarbon anion C5H5(-). Li7(BH)5(+), along with Li7C5(+), Li7Si5(+) and Li7Ge5(+), joins a select group of clusters that adopt a seven-peak star-shape geometry, which is favored by aromaticity in the central five-membered ring, and by the preference of Li atoms for bridging positions. The theoretical analysis of chemical bonding, based on magnetic criteria, supports the notion that electronic delocalization is an important stabilization factor in all these star-shaped clusters.

Influence of milling parameters on the sorption properties of the LiH–MgB{sub 2} system doped with TiCl{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Busch, Nina; Jepsen, Julian; Pistidda, Claudio [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Puszkiel, Julián A. [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Combatientes de Malvinas 3150, 1427 Buenos Aires (Argentina); Karimi, Fahim [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Milanese, Chiara [Pavia H_2 Lab, Department of Chemistry, Physical Chemistry Division, University of Pavia, Viale Taramelli 16, I-27100 Pavia (Italy); Tolkiehn, Martin [SRXPD Beamline HASYLAB, Deutsches-Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Chaudhary, Anna-Lisa, E-mail: anna-lisa.chaudhary@hzg.de [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Klassen, Thomas; Dornheim, Martin [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany)

2015-10-05

Highlights: • The LiH–MgB{sub 2} system was doped with TiCl{sub 3} and milling conditions varied. • A heuristic model was used to estimate energy transfer from milling conditions. • Milling parameters were correlated with the energy transfer calculation. • 20 kJ g{sup −1} of energy transfer correlates to the optimum conditions for the system. - Abstract: Hydrogen sorption properties of the LiH–MgB{sub 2} system doped with TiCl{sub 3} were investigated with respect to milling conditions (milling times, ball to powder (BTP) ratios, rotation velocities and degrees of filling) to form the reactive hydride composite (RHC) LiBH{sub 4}–MgH{sub 2}. A heuristic model was applied to approximate the energy transfer from the mill to the powders. These results were linked to experimentally obtained quantities such as crystallite size, specific surface area (SSA) and homogeneity of the samples, using X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method and scanning electron microscopy (SEM), respectively. The results show that at approximately 20 kJ g{sup −1} there are no further benefits to the system with an increase in energy transfer. This optimum energy transfer value indicates that a plateau was reached for MgB{sub 2} crystallite size therefore the there was also no improvement of reaction kinetics due to no change in crystallite size. Therefore, this study shows that an optimum energy transfer value was reached for the LiH–MgB{sub 2} system doped with TiCl{sub 3}.

Phase transition in Li{sub 1/2}Bi{sub 1/2}TiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Barik, Subrat K; Choudhary, R N.P. [Dept. of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur (India); Mahapatra, P K [Dept. of Physics and Technophysics, Vidyasagar Univ., Midnapur (India)

2008-07-01

Full text: Recent advancements in the electronics in this miniaturization age are found in many ferroelectric based materials of different structural families. Among them, perovskites are being used for the possible forefront applications in the areas of research as well as in industrial applications. Though a lot of lead-based compounds like PZT, PMN etc. have been investigated for device applications, the manufacturing companies are now heading towards the environmental friendly lead-free compounds. Li{sub 1/2}Bi{sub 1/2}TiO{sub 3} comes under this group. Here we report the studies of phase transition of Li{sub 1/2}Bi{sub 1/2}TiO{sub 3} (LBT) ceramic which was prepared by a mixed-oxide technique. The formation of the compound was confirmed by XRD studies. The dielectric permittivity, the loss tangent and polarization of the sample were studied in a wide frequency and temperature range. Detailed analysis of impedance spectrum obtained at different temperatures and frequencies suggested that the electrical properties of the material are strongly temperature dependant. The Nequist plots clearly showed the presence of both bulk and grain boundary effect in the compound. The frequency dependent ac conductivity at different temperatures indicated the conduction process is thermally activated. The activation energy was calculated from the temperature variation of d.c. conductivity.

Surfactant-assisted sol gel preparation of high-surface area mesoporous TiO2 nanocrystalline Li-ion battery anodes

International Nuclear Information System (INIS)

Casino, S.; Di Lupo, F.; Francia, C.; Tuel, A.; Bodoardo, S.; Gerbaldi, C.

2014-01-01

Highlights: • Mesoporous TiO 2 nanocrystalline lithium battery anodes with tunable morphology. • Simple sol–gel technique using different cationic surfactants is adopted. • Textural/morphological characteristics define the electrochemical behaviour. • TiO 2 anatase using C16TAB exhibits stable performance after 200 cycles. • It shows promising prospects as high-voltage safe Li-ion battery anode. - Abstract: We here investigate the physico-chemical/morphological characteristics and cycling behaviour of several kinds of nanocrystalline TiO 2 Li-ion battery anodes selectively prepared through a simple sol–gel strategy based on a low-cost titanium oxysulfate precursor, by mediation of different cationic surfactants having different features (e.g., chain lengths, counter ion, etc.): i.e., cetyl-trimethylammonium bromide (CTAB), cetyl-trimethylammonium chloride (CTAC), benzalkonium chloride (BC) or octadecyl-trimethyl ammonium bromide (C 18 TAB). X-ray diffraction profiles reveal single phase anatase having good correspondence with the reference pattern when using short chain CTAB, while in the other cases the presence of chloride and/or an increased chain length affect the purity of the samples. FESEM analysis reveal nanosized particles forming cauliflower-like aggregates. TiO 2 materials demonstrate mesoporous characteristics and large specific surface area ranging from 250 to 30 m 2 g −1 . Remarkably stable electrode performance are achieved by appropriately selecting the cationic surfactant and the surfactant/precursor ratio. Detailed analysis is provided on the effect of the reaction conditions upon the formation of mesoporous crystalline titania enlightening new directions for the development of high performing lithium storage electrodes by a simple and low cost sol–gel strategy

Evaluation of the thermoluminescent detector answers of CaSO{sub 4}:Dy, LiF:Mg,Ti and micro LiF:Mg,Ti in photon clinical beams dosimetry using water simulator; Avaliacao da resposta de detectores termoluminescentes de CaSO4:Dy, LiF:Mg,Ti e microLiF:Mg,Ti na dosimetria de feixes clinicos de fotons utilizando simulador de agua

Energy Technology Data Exchange (ETDEWEB)

Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Leticia L., E-mail: lmatsushima@usp.b, E-mail: veneziani@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (GMR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes; Sakuraba, Roberto K.; Cruz, Jose C. da, E-mail: rsakuraba@einstein.b, E-mail: jccruz@einstein.b [Sociedade Beneficente Israelita Brasileira, Sao Paulo, SP (Brazil). Hospital Albert Einstein (HAE)

2011-10-26

This paper perform the comparative study of thermoluminescent answer of calcium sulfate dosemeter doped with dysprosium (DaSO{sub 4}:Dy) produced by the IPEN, Sao Paulo, with answer of lithium fluoride dosemeters doped with magnesium and titanium (LiF:Mg, Ti) in the dosimetry of clinical beams of photons (6 and 15 MV) by using water simulator object. Dose-answer curves were obtained for gamma radiation of cobalt-60 in the air and in conditions of electronic equilibrium (plate of PMMA), and clinical photons of CLINAC model 2100C accelerators of the two evaluated hospitals: Hospital das Clinicas of the Faculty of Medicine of Sao Paulo university and Hospital Albert Einstein. It was also evaluated the sensitivity and reproduction of the three dosemeters

Adiponitrile-Lithium Bis(trimethylsulfonyl)imide Solutions as Alkyl Carbonate-free Electrolytes for Li4 Ti5 O12 (LTO)/LiNi1/3 Co1/3 Mn1/3 O2 (NMC) Li-Ion Batteries.

Science.gov (United States)

Farhat, Douaa; Ghamouss, Fouad; Maibach, Julia; Edström, Kristina; Lemordant, Daniel

2017-05-19

Recently, dinitriles (NC(CH 2 ) n CN) and especially adiponitrile (ADN, n=4) have attracted attention as safe electrolyte solvents owing to their chemical stability, high boiling points, high flash points, and low vapor pressure. The good solvation properties of ADN toward lithium salts and its high electrochemical stability (≈6 V vs. Li/Li + ) make it suitable for safer Li-ions cells without performance loss. In this study, ADN is used as a single electrolyte solvent with lithium bis(trimethylsulfonyl)imide (LiTFSI). This electrolyte allows the use of aluminium collectors as almost no corrosion occurs at voltages up to 4.2 V. The physicochemical properties of the ADN-LiTFSI electrolyte, such as salt dissolution, conductivity, and viscosity, were determined. The cycling performances of batteries using Li 4 Ti 5 O 12 (LTO) as the anode and LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NMC) as the cathode were determined. The results indicate that LTO/NMC batteries exhibit excellent rate capabilities with a columbic efficiency close to 100 %. As an example, cells were able to reach a capacity of 165 mAh g -1 at 0.1 C and a capacity retention of more than 98 % after 200 cycles at 0.5 C. In addition, electrodes analyses by SEM, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy after cycling confirming minimal surface changes of the electrodes in the studied battery system. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly-crystalline ultrathin gadolinium doped and carbon-coated Li4Ti5O12 nanosheets for enhanced lithium storage

Science.gov (United States)

Xu, G. B.; Yang, L. W.; Wei, X. L.; Ding, J. W.; Zhong, J. X.; Chu, P. K.

2015-11-01

Highly-crystalline gadolinium doped and carbon-coated ultrathin Li4Ti5O12 (LTO) nanosheets (denoted as LTO-Gd-C) as an anode material for Li-ion batteries (LIBs) are synthesized on large scale by controlling the amount of carbon precursor in the topotactic transformation of layered ultrathin Li1.81H0.19Ti2O5·xH2O (H-LTO) nanosheets at 700 °C. The characterizations of structure and morphology reveal that the gadolinium doped and carbon-coated ultrathin LTO nanosheets have high crystallinity with a thickness of about 10 nm. Gadolinium doping allows the spinel LTO products to be stabilized, thereby preserving the precursor's sheet morphology and single crystal structure. Carbon encapsulation serves dual functions by restraining crystal growth of the LTO primary nanoparticles in the LTO-Gd-C nanosheets and decreasing the external electron transport resistance. Owing to the synergistic effects rendered by ultrathin nanosheets with high crystallinity, gadolinium doping and carbon coating, the developed ultrathin LTO nanosheets possess excellent specific capacity, cycling performance, and rate capability compared with reference materials, when evaluated as an anode material for lithium ion batteries (LIBs). The simple and effective strategy encompassing nanoscale morphological engineering, surface modification, and doping improves the performance of LTO-based anode materials for high energy density and high power LIBs applied in large scale energy storage.

Selective blockade of microRNA processing by Lin-28

Science.gov (United States)

Viswanathan, Srinivas R.; Daley, George Q.; Gregory, Richard I.

2012-01-01

MicroRNAs (miRNAs) play critical roles in development, and dysregulation of miRNA expression has been observed in human malignancies. Recent evidence suggests that the processing of several primary miRNA transcripts (pri-miRNAs) is blocked post-transcriptionally in embryonic stem (ES) cells, embryonal carcinoma (EC) cells, and primary tumors. Here we show that Lin-28, a developmentally regulated RNA-binding protein, selectively blocks the processing of pri-let-7 miRNAs in embryonic cells. Using in vitro and in vivo studies, we demonstrate that Lin-28 is necessary and sufficient for blocking Microprocessor-mediated cleavage of pri-let-7 miRNAs. Our results identify Lin-28 as a negative regulator of miRNA biogenesis and suggest that Lin-28 may play a central role in blocking miRNA-mediated differentiation in stem cells and certain cancers. PMID:18292307

Modal and polarization qubits in Ti:LiNbO3 photonic circuits for a universal quantum logic gate.

Science.gov (United States)

Saleh, Mohammed F; Di Giuseppe, Giovanni; Saleh, Bahaa E A; Teich, Malvin Carl

2010-09-13

Lithium niobate photonic circuits have the salutary property of permitting the generation, transmission, and processing of photons to be accommodated on a single chip. Compact photonic circuits such as these, with multiple components integrated on a single chip, are crucial for efficiently implementing quantum information processing schemes.We present a set of basic transformations that are useful for manipulating modal qubits in Ti:LiNbO(3) photonic quantum circuits. These include the mode analyzer, a device that separates the even and odd components of a state into two separate spatial paths; the mode rotator, which rotates the state by an angle in mode space; and modal Pauli spin operators that effect related operations. We also describe the design of a deterministic, two-qubit, single-photon, CNOT gate, a key element in certain sets of universal quantum logic gates. It is implemented as a Ti:LiNbO(3) photonic quantum circuit in which the polarization and mode number of a single photon serve as the control and target qubits, respectively. It is shown that the effects of dispersion in the CNOT circuit can be mitigated by augmenting it with an additional path. The performance of all of these components are confirmed by numerical simulations. The implementation of these transformations relies on selective and controllable power coupling among single- and two-mode waveguides, as well as the polarization sensitivity of the Pockels coefficients in LiNbO(3).

The Formation of Lithiated Ti-Doped {alpha}-Fe{sub 2}O{sub 3} Nanocrystalline Particles by Mechanical Milling of Ti-Doped Lithium Spinel Ferrite

Energy Technology Data Exchange (ETDEWEB)

Widatallah, H. M., E-mail: hisham@ictp.trieste.it [Khartoum University, Department of Physics (Sudan); Gismelseed, A. M.; Bouziane, K. [Sultan Qaboos University, Department of Physics (Oman); Berry, F. J. [Open University, Department of Chemistry (United Kingdom); Al Rawas, A. D.; Al-Omari, I. A.; Yousif, A. A.; Elzain, M. E. [Sultan Qaboos University, Department of Physics (Oman)

2004-12-15

The milling of spinel-related Ti-doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} for different times is studied with XRD, Moessbauer spectroscopy and magnetic measurements. Milling converts the material to Li-Ti-doped {alpha}-Fe{sub 2}O{sub 3} nanocrystalline particles via an intermediate {gamma}-LiFeO{sub 2}-related phase. The role played by the dopant Ti-ion in the process is emphasized.

Depth profiling the solid electrolyte interphase on lithium titanate (Li4Ti5O12) using synchrotron-based photoelectron spectroscopy

DEFF Research Database (Denmark)

Nordh, Tim; Younesi, Reza; Brandell, Daniel

2015-01-01

The presence of a surface layer on lithium titanate (Li4Ti5O12, LTO) anodes, which has been a topic of debate in scientific literature, is here investigated with tunable high surface sensitive synchrotron-based photoelectron spectroscopy (PES) to obtain a reliable depth profile of the interphase...

Microwave-assisted reactive sintering and lithium ion conductivity of Li1.3Al0.3Ti1.7(PO4)3 solid electrolyte

Science.gov (United States)

Hallopeau, Leopold; Bregiroux, Damien; Rousse, Gwenaëlle; Portehault, David; Stevens, Philippe; Toussaint, Gwenaëlle; Laberty-Robert, Christel

2018-02-01

Li1.3Al0.3Ti1.7(PO4)3 (LATP) materials are made of a three-dimensional framework of TiO6 octahedra and PO4 tetrahedra, which provides several positions for Li+ ions. The resulting high ionic conductivity is promising to yield electrolytes for all-solid-state Li-ion batteries. In order to elaborate dense ceramics, conventional sintering methods often use high temperature (≥1000 °C) with long dwelling times (several hours) to achieve high relative density (∼90%). In this work, an innovative synthesis and processing approach is proposed. A fast and easy processing technique called microwave-assisted reactive sintering is used to both synthesize and sinter LATP ceramics with suitable properties in one single step. Pure and crystalline LATP ceramics can be achieved in only 10 min at 890 °C starting from amorphous, compacted LATP's precursors powders. Despite a relative density of 88%, the ionic conductivity measured at ambient temperature (3.15 × 10-4 S cm-1) is among the best reported so far. The study of the activation energy for Li+ conduction confirms the high quality of the ceramic (purity and crystallinity) achieved by using this new approach, thus emphasizing its interest for making ion-conducting ceramics in a simple and fast way.

Hydrogen desorption reactions of Li-N-H hydrogen storage system: Estimation of activation free energy

International Nuclear Information System (INIS)

Matsumoto, Mitsuru; Haga, Tetsuya; Kawai, Yasuaki; Kojima, Yoshitsugu

2007-01-01

The dehydrogenation reactions of the mixtures of lithium amide (LiNH 2 ) and lithium hydride (LiH) were studied under an Ar atmosphere by means of temperature programmed desorption (TPD) technique. The dehydrogenation reaction of the LiNH 2 /LiH mixture was accelerated by addition of 1 mol% Ti(III) species (k = 3.1 x 10 -4 s -1 at 493 K), and prolonged ball-milling time (16 h) further enhanced reaction rate (k = 1.1 x 10 -3 s -1 at 493 K). For the hydrogen desorption reaction of Ti(III) doped samples, the activation energies estimated by Kissinger plot (95 kJ mol -1 ) and Arrhenius plot (110 kJ mol -1 ) were in reasonable agreement. The LiNH 2 /LiH mixture without Ti(III) species, exhibited slower hydrogen desorption process and the kinetic traces deviated from single exponential behavior. The results indicated the Ti(III) additives change the hydrogen desorption reaction mechanism of the LiNH 2 /LiH mixture

Ti@δ-MnO_2 core-shell nanowire arrays as self-supported electrodes of supercapacitors and Li ion batteries

International Nuclear Information System (INIS)

Zhao, Guangyu; Zhang, Dong; Zhang, Li; Sun, Kening

2016-01-01

Highlights: • Ti@δ-MnO_2 core-shell nanowire arrays prepared by a electrochemical method. • Remarkable rate capability as both Li ion battery and supercapacitor electrodes. • Good electronic conductivity and facilitated mass transport. - Abstract: δ-MnO_2 is a promissing electrode material of supercapacitors and Li ion batteries (LIBs) owing to its low cost, layer structure and composite valence of Mn. However, the unfavorable electronic conductivity of δ-MnO_2 restricts its rate capability in both of the two devices. Herein, a vertically standing Ti nanowire array modified with δ-MnO_2 nanoflakes is prepared by a electrodeposition method, and the electrochemical properties of Ti@δ-MnO_2 nanowire arrays in supercapacitors and LIBs are investigated. The results show that, the arrays have a capacity of 195 F g"−"1 at 1.0 A g"−"1 and can cycle more than 10000 rounds at 10 A g"−"1 as electrodes of supercapacitors. On the other hand, the arrays behave good rate capability as LIB cathodes, which can release a capacity of 70 mAh g"−"1 at 10C rate charge/discharge. We suggest that, the good electronic conductivity owing to the core-shell structure and the facilitated mass transport supplied by the array architecture are responsible for the enhanced rate performances in the two devices.

Investigation of various synthetic conditions for large-scale synthesis and electrochemical properties of Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C as anode material

Energy Technology Data Exchange (ETDEWEB)

Dong, Guo-Hui, E-mail: dgh1516@gmail.com [Shanghai Shanshan Tech Co., Ltd., 3158 Jinhai Road, Shanghai 201209 (China); Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Liu, Hua-Jing; Zhou, Liang [Shanghai Shanshan Tech Co., Ltd., 3158 Jinhai Road, Shanghai 201209 (China); Shanghai Second Polytechnic University, 2360 Jinhai Road, Shanghai 201209 (China); Chong, Lina; Yang, Jun [Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Qiao, Yong-Min; Zhang, Dian-Hao [Shanghai Shanshan Tech Co., Ltd., 3158 Jinhai Road, Shanghai 201209 (China)

2014-12-05

Graphical abstract: A gel and spray-drying method is demonstrated for large-scale preparation of Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C secondary microspheres via optimizing various synthetic conditions. The electrochemical performances of the Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C microspheres are investigated. - Highlights: • Various synthetic conditions are investigated. • Materials can be produced at ∼1 kg scale by using our demonstrated synthesis method. • Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C sample possesses high electronic conductivity and rate property, and excellent cycling performance. • Secondary micro-spherical Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C sample has high tap density et al. - Abstract: Poor electronic conductivity is one of the biggest obstacles for practical application of lithium titanate as lithium-ion battery anode material. Utilizing the advantages of coating and doping techniques to optimize the conductive and rate performances of lithium titanate was reported in this work. Herein, the effects of various synthetic conditions including calcination temperatures and holding times, lithium overdoses, carbon contents, doping contents and doping elements on phase, primary particles’ size and electrochemical performance were comprehensively investigated. The optimal Li{sub 3.98}Al{sub 0.06}Ti{sub 4.96}O{sub 12}/C secondary microspheres were synthesized, which possessed high electronic conductivity, tap density, reversible capacity and first columbic efficiency, and excellent rate performances. Furthermore, the synthesized samples were characterized by various techniques.

Effects of TiO2 addition on microwave dielectric properties of Li2MgSiO4 ceramics

Science.gov (United States)

Rose, Aleena; Masin, B.; Sreemoolanadhan, H.; Ashok, K.; Vijayakumar, T.

2018-03-01

Silicates have been widely studied for substrate applications in microwave integrated circuits owing to their low dielectric constant and low tangent loss values. Li2MgSiO4 (LMS) ceramics are synthesized through solid-state reaction route using TiO2 as an additive to the pure ceramics. Variations in dielectric properties of LMS upon TiO2 addition in different weight percentages (0.5, 1.5, 2) are studied by keeping the sintering parameters constant. Crystalline structure, phase composition, and microstructure of LMS and LMS-TiO2 ceramics were studied using x-ray diffraction spectrometer and High Resolution Scanning electron microscope. Density was measured through Archimedes method and the microwave dielectric properties were examined by Cavity perturbation technique. LMS achieved relative permittivity (ε r) of 5.73 and dielectric loss (tan δ) of 5.897 × 10‑4 at 8 GHz. In LMS-TiO2 ceramics, 0.5 wt% TiO2 added LMS showed comparatively better dielectric properties than other weight percentages where ε r = 5.67, tan δ = 7.737 × 10‑4 at 8 GHz.

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

DEFF Research Database (Denmark)

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

2012-01-01

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

Influence of different substrates on the ionic conduction in LiCoO{sub 2}/LiNbO{sub 3} thin-film bi-layers

Energy Technology Data Exchange (ETDEWEB)

Horopanitis, E.E.; Perentzis, G.; Papadimitriou, L. [Aristotle University of Thessaloniki, Department of Physics, Section of Solid State Physics, Thessaloniki (Greece)

2008-07-01

LiNbO{sub 3} thin films, deposited by e-gun evaporation, show lithium deficiency, which is cured by ''Li doping''. The ''Li doping'' of the films was achieved by preparing a structure of Li-Nb-O/Li/Li-Nb-O, which after annealing forms a homogenized LiNbO{sub 3} layer because of diffusion of Li in the two Li-Nb-O layers. The LiCoO{sub 2}/LiNbO{sub 3} bi-layers were prepared either on Stainless Steel/TiN or on Al{sub 2}O{sub 3}/Co/Pt substrates/ohmic-contacts by depositing first either the cathode LiCoO{sub 2} or the electrolyte LiNbO{sub 3}. The Nyquist plots of the AC impedance measurements of all structures showed that the interfaces prepared on Stainless-Steel/TiN consisted of two semicircles. The structures deposited on Al{sub 2}O{sub 3}/Co/Pt showed a third semicircle, which is probably due to the roughness of the substrate. It is important that the ionic properties of the bi-layers with the cathode material deposited first, a usual structure in a microbattery, are improved compared to the other structures. The quality of the LiNbO{sub 3} layer depends very much on the substrate. It can be evaluated from Arrhenius plots that the activation energy of this layer is considerably lower when the whole structure is deposited on Stainless Steel/TiN. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Rutile TiO2 nanorod arrays directly grown on Ti foil substrates towards lithium-ion micro-batteries

International Nuclear Information System (INIS)

Dong Shanmu; Wang Haibo; Gu Lin; Zhou Xinhong; Liu Zhihong; Han Pengxian; Wang Ya; Chen Xiao; Cui Guanglei; Chen Liquan

2011-01-01

Nanosized rutile TiO 2 is one of the most promising candidates for anode material in lithium-ion micro-batteries owing to their smaller dimension in ab-plane resulting in an enhanced performance for area capacity. However, few reports have yet emerged up to date of rutile TiO 2 nanorod arrays growing along c-axis for Li-ion battery electrode application. In this study, single-crystalline rutile TiO 2 nanorod arrays growing directly on Ti foil substrates have been fabricated using a template-free method. These nanorods can significantly improve the electrochemical performance of rutile TiO 2 in Li-ion batteries. The capacity increase is about 10 times in comparison with rutile TiO 2 compact layer.

Assessment of CaSO4:Dy and LiF:Mg,Ti thermoluminescent dosimeters performance in the dosimetry of clinical electron beams

International Nuclear Information System (INIS)

Nunes, Maira Goes

2008-01-01

The assessment of the performance of CaS0 4 :Dy thermoluminescent detectors produced by IPEN in the dosimetry of clinical electron beams aims to propose an alternative to the LiF:Mg,Ti commercial dosimeters (TLD-100) largely applied in radiation therapy. The two types of thermoluminescent dosimeters were characterised with the use of PMMA, RMI-457 type solid water and water phantoms in radiation fields of 4, 6, 9, 12 and 16 MeV electrons of nominal energies in which the dose-response curves were obtained and the surface and depth doses were determined. The thermoluminescent response dependency with the electron nominal energies and the applied phantom were studied. The CaS0 4 :Dy presented the same behaviour than the LiF:Mg,Ti in such a way that its application as an alternative to the TLD-100 pellets in the radiation therapy dosimetry of electron beams is viable and presents the significantly higher sensitivity to the electron radiation as its main advantage. (author)

A new, high energy rechargeable lithium ion battery with a surface-treated Li{sub 1.2}Mn{sub 0.54}Ni{sub 0.13}Co{sub 0.13}O{sub 2} cathode and a nano-structured Li{sub 4}Ti{sub 5}O{sub 12} anode

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaoyu; Huang, Tao; Yu, Aishui, E-mail: asyu@fudan.edu.cn

2015-11-05

Through elaborate design, a new rechargeable lithium ion battery has been developed by comprising a surface-treated Li{sub 1.2}Mn{sub 0.54}Ni{sub 0.13}Co{sub 0.13}O{sub 2} cathode and a nano-structured Li{sub 4}Ti{sub 5}O{sub 12} anode. After precondition Na{sub 2}S{sub 2}O{sub 8} treatment, the initial coulombic efficiency of Li{sub 1.2}Mn{sub 0.54}Ni{sub 0.13}Co{sub 0.13}O{sub 2} cathode has been significantly increased and can be compatible with that of the nano-structured Li{sub 4}Ti{sub 5}O{sub 12} anode. The optimization of structure and morphology for both active electrode materials result in their remarkable electrochemical performances in respective lithium half-cells. Ultimately, the rechargeable lithium ion full battery consisting of both electrodes delivers a specific capacity of 99.0 mAh g{sup −1} and a practical energy density of 201 Wh kg{sup −1}, based on the total weight of both active electrode materials. Furthermore, as a promising candidate in the lithium ion battery field, this full battery also achieves highly attractive electrochemical performance with high coulombic efficiency, excellent cycling stability and outstanding rate capability. Thus the proposed battery displays broad practical application prospects for next generation of high-energy lithium ion battery. - Highlights: • The Li{sub 1.2}Mn{sub 0.54}Ni{sub 0.13}Co{sub 0.13}O{sub 2} cathode is surface-treated by Na{sub 2}S{sub 2}O{sub 8}. • The nano-sized Li{sub 4}Ti{sub 5}O{sub 12} anode is obtained by a solid-state method. • A new Li{sub 1.2}Mn{sub 0.54}Ni{sub 0.13}Co{sub 0.13}O{sub 2}/Li{sub 4}Ti{sub 5}O{sub 12} lithium ion battery is developed. • The battery shows high coulombic efficiency, specific capacity and energy density. • The battery shows high capacity retention rate and good high-rate capability.

Surfactant-assisted sol gel preparation of high-surface area mesoporous TiO{sub 2} nanocrystalline Li-ion battery anodes

Energy Technology Data Exchange (ETDEWEB)

Casino, S. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Di Lupo, F., E-mail: francesca.dilupo@polito.it [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Francia, C. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Tuel, A. [IRCELYON, Institut de Recherches sur la Catalyse et l’environnement de Lyon, UMR 5256, CNRS-Université de Lyon 1, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex (France); Bodoardo, S. [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy); Gerbaldi, C., E-mail: claudio.gerbaldi@polito.it [GAME Lab, Department of Applied Science and Technology – DISAT, Institute of Chemistry, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino (Italy)

2014-05-01

Highlights: • Mesoporous TiO{sub 2} nanocrystalline lithium battery anodes with tunable morphology. • Simple sol–gel technique using different cationic surfactants is adopted. • Textural/morphological characteristics define the electrochemical behaviour. • TiO{sub 2} anatase using C16TAB exhibits stable performance after 200 cycles. • It shows promising prospects as high-voltage safe Li-ion battery anode. - Abstract: We here investigate the physico-chemical/morphological characteristics and cycling behaviour of several kinds of nanocrystalline TiO{sub 2} Li-ion battery anodes selectively prepared through a simple sol–gel strategy based on a low-cost titanium oxysulfate precursor, by mediation of different cationic surfactants having different features (e.g., chain lengths, counter ion, etc.): i.e., cetyl-trimethylammonium bromide (CTAB), cetyl-trimethylammonium chloride (CTAC), benzalkonium chloride (BC) or octadecyl-trimethyl ammonium bromide (C{sub 18}TAB). X-ray diffraction profiles reveal single phase anatase having good correspondence with the reference pattern when using short chain CTAB, while in the other cases the presence of chloride and/or an increased chain length affect the purity of the samples. FESEM analysis reveal nanosized particles forming cauliflower-like aggregates. TiO{sub 2} materials demonstrate mesoporous characteristics and large specific surface area ranging from 250 to 30 m{sup 2} g{sup −1}. Remarkably stable electrode performance are achieved by appropriately selecting the cationic surfactant and the surfactant/precursor ratio. Detailed analysis is provided on the effect of the reaction conditions upon the formation of mesoporous crystalline titania enlightening new directions for the development of high performing lithium storage electrodes by a simple and low cost sol–gel strategy.

Evaluation of the thermoluminescent detector answers of CaSO4:Dy, LiF:Mg,Ti and micro LiF:Mg,Ti in photon clinical beams dosimetry using water simulator

International Nuclear Information System (INIS)

Matsushima, Luciana C.; Veneziani, Glauco R.; Campos, Leticia L.

2011-01-01

This paper perform the comparative study of thermoluminescent answer of calcium sulfate dosemeter doped with dysprosium (DaSO 4 :Dy) produced by the IPEN, Sao Paulo, with answer of lithium fluoride dosemeters doped with magnesium and titanium (LiF:Mg, Ti) in the dosimetry of clinical beams of photons (6 and 15 MV) by using water simulator object. Dose-answer curves were obtained for gamma radiation of cobalt-60 in the air and in conditions of electronic equilibrium (plate of PMMA), and clinical photons of CLINAC model 2100C accelerators of the two evaluated hospitals: Hospital das Clinicas of the Faculty of Medicine of Sao Paulo university and Hospital Albert Einstein. It was also evaluated the sensitivity and reproduction of the three dosemeters

Multiple transcription factors directly regulate Hox gene lin-39 expression in ventral hypodermal cells of the C. elegans embryo and larva, including the hypodermal fate regulators LIN-26 and ELT-6.

Science.gov (United States)

Liu, Wan-Ju; Reece-Hoyes, John S; Walhout, Albertha J M; Eisenmann, David M

2014-05-13

Hox genes encode master regulators of regional fate specification during early metazoan development. Much is known about the initiation and regulation of Hox gene expression in Drosophila and vertebrates, but less is known in the non-arthropod invertebrate model system, C. elegans. The C. elegans Hox gene lin-39 is required for correct fate specification in the midbody region, including the Vulval Precursor Cells (VPCs). To better understand lin-39 regulation and function, we aimed to identify transcription factors necessary for lin-39 expression in the VPCs, and in particular sought factors that initiate lin-39 expression in the embryo. We used the yeast one-hybrid (Y1H) method to screen for factors that bound to 13 fragments from the lin-39 region: twelve fragments contained sequences conserved between C. elegans and two other nematode species, while one fragment was known to drive reporter gene expression in the early embryo in cells that generate the VPCs. Sixteen transcription factors that bind to eight lin-39 genomic fragments were identified in yeast, and we characterized several factors by verifying their physical interactions in vitro, and showing that reduction of their function leads to alterations in lin-39 levels and lin-39::GFP reporter expression in vivo. Three factors, the orphan nuclear hormone receptor NHR-43, the hypodermal fate regulator LIN-26, and the GATA factor ELT-6 positively regulate lin-39 expression in the embryonic precursors to the VPCs. In particular, ELT-6 interacts with an enhancer that drives GFP expression in the early embryo, and the ELT-6 site we identified is necessary for proper embryonic expression. These three factors, along with the factors ZTF-17, BED-3 and TBX-9, also positively regulate lin-39 expression in the larval VPCs. These results significantly expand the number of factors known to directly bind and regulate lin-39 expression, identify the first factors required for lin-39 expression in the embryo, and hint at a

Humidity Sensitivity of MgCr2O4-TiO2-LiO2 Ceramics Sensor Prepared by Sol-Gel Routes

Directory of Open Access Journals (Sweden)

H. Y. He

2010-05-01

Full Text Available 79.5MgCr2O4–19.5TiO2–Li2O porous ceramics were investigated as a humidity sensor. The sensors obtain by a cold isostatic pressing and sintering of the fine MgCr2O4 and TiO2 and LiCO3 powders. The MgCr2O4 and TiO2 powders were respectively synthesized by sol-gel methods. The effects of sintering temperature on the humidity sensitivity of sensors were studied by measuring electrical resistance in different conditions of relative humidity (R.H. at 27 °C. The results indicated that the calcining temperature obviously affected the resistance variation of the sensor in range of 11.3-84.7 % RH. The resistance variation was small at the calcining temperature of 600 oC for 2 h. With increasing calcining temperature, the resistance variation increased to 5.4×104% and 7.0×104 % at 800 oC and 1000 oC for 2 h, but decreased to 3.1×104 % at 1200 oC for 2 h respectively. The response times are 25 s and 35 s respectively for humidity adsorption and humidity desorption between 11.3 %RH and 84.7 %RH.

Dynamic globularization of a-phase in Ti6Al4V alloy during hot compression

CSIR Research Space (South Africa)

Mutombo, K

2013-12-01

Full Text Available composition dependence of the martensite start temperature (Ms) has been done for Ti-Fe, Ti-Cr, Ti-Mo, Ti-V, Ti-Nb, Ti-Zr and Ti-Al alloys [1], [2]. The beneficial effect on the formation of hexagonal-structured martensite (α′) of Al, Mn, Cr, Sn and Fe... alloying elements, has been discussed by Lin et al [4]. However, the formation of the orthorhombic-structured martensite (α′′) which is favoured by elements such as Nb, Mo, Zr, W and V (strong β stabilizers) or H (a strong β stabilizer), has been reported...

Phosphidation of Li4Ti5O12 nanoparticles and their electrochemical and biocompatible superiority for lithium rechargeable batteries.

Science.gov (United States)

Jo, Mi Ru; Nam, Ki Min; Lee, Youngmin; Song, Kyeongse; Park, Joon T; Kang, Yong-Mook

2011-11-07

Phosphidated-Li(4)Ti(5)O(12) shows high capacity with a significantly enhanced kinetics opening new possibilities for ultra-fast charge/discharge of lithium rechargeable batteries. The in vitro cytotoxicity test proves its fabulous cell viability, indicating that the toxicity problem of nanoparticles can be also solved by phosphidation. This journal is © The Royal Society of Chemistry 2011

The Lin28/let-7 Axis Regulates Glucose Metabolism

NARCIS (Netherlands)

Zhu, Hao; Shyh-Chang, Ng; Segre, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G.; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

2011-01-01

The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating-metabolism. When overexpressed in mice, both

H2O2 assisted room temperature oxidation of Ti2C MXene for Li-ion battery anodes

KAUST Repository

Ahmed, Bilal

2016-03-08

Herein we demonstrate that a prominent member of the MXene family, Ti2C, undergoes surface oxidation at room temperature when treated with hydrogen peroxide (H2O2). The H2O2 treatment results in opening up of MXene sheets and formation of TiO2 nanocrystals on their surface, which is evidenced by the high surface area of H2O2 treated MXene and X-ray diffraction (XRD) analysis. We show that the reaction time and the amount of hydrogen peroxide used are the limiting factors, which determine the morphology and composition of the final product. Furthermore, it is shown that the performance of H2O2 treated MXene as an anode material in Li ion batteries (LIBs) was significantly improved as compared to as-prepared MXenes. For instance, after 50 charge/discharge cycles, specific discharge capacities of 389 mA h g−1, 337 mA h g−1 and 297 mA h g−1 were obtained for H2O2 treated MXene at current densities of 100 mA g−1, 500 mA g−1 and 1000 mA g−1, respectively. In addition, when tested at a very high current density, such as 5000 mA g−1, the H2O2 treated MXene showed a specific capacity of 150 mA h g−1 and excellent rate capability. These results clearly demonstrate that H2O2 treatment of Ti2C MXene improves MXene properties in energy storage applications, such as Li ion batteries or capacitors.

H2O2 assisted room temperature oxidation of Ti2C MXene for Li-ion battery anodes

KAUST Repository

Ahmed, Bilal; Anjum, Dalaver H.; Hedhili, Mohamed N.; Gogotsi, Yury; Alshareef, Husam N.

2016-01-01

Herein we demonstrate that a prominent member of the MXene family, Ti2C, undergoes surface oxidation at room temperature when treated with hydrogen peroxide (H2O2). The H2O2 treatment results in opening up of MXene sheets and formation of TiO2 nanocrystals on their surface, which is evidenced by the high surface area of H2O2 treated MXene and X-ray diffraction (XRD) analysis. We show that the reaction time and the amount of hydrogen peroxide used are the limiting factors, which determine the morphology and composition of the final product. Furthermore, it is shown that the performance of H2O2 treated MXene as an anode material in Li ion batteries (LIBs) was significantly improved as compared to as-prepared MXenes. For instance, after 50 charge/discharge cycles, specific discharge capacities of 389 mA h g−1, 337 mA h g−1 and 297 mA h g−1 were obtained for H2O2 treated MXene at current densities of 100 mA g−1, 500 mA g−1 and 1000 mA g−1, respectively. In addition, when tested at a very high current density, such as 5000 mA g−1, the H2O2 treated MXene showed a specific capacity of 150 mA h g−1 and excellent rate capability. These results clearly demonstrate that H2O2 treatment of Ti2C MXene improves MXene properties in energy storage applications, such as Li ion batteries or capacitors.

Ab initio study of isomerism in molecular Li2AB+ ions with 12 and 14 valence electrons

International Nuclear Information System (INIS)

Charkin, O.P.; Klimenko, N.M.; Mak-Ki, M.L.; Shlojer, P.R.

1997-01-01

Ab initio calculations of potential energy surfaces (PES) of molecular ions Li 2 AB + with 12 and 14 valence electrons have been made in the framework of approximations MP2/6-31G*//HF/6-31G*+ZPE(HF/6-31G*) and MP4SDTQ/6-31*//MP2/6-31G*+ZPE(MP2/6-31G*). The following most favourable structures have been found: a double-terminal linear for LiNO + (a triplet); a plane bicyclic one for Li 2 OF + , Li 2 SCl + , Li 2 NO + (a singlet) and Li 2 PS + (a singlet), where both cations are coordinated to A-B bond; rectangular (T-shaped) for Li 2 OCl + and SFLi + , as well as for LiNS + and POLi 2 + ions in singlet and triplet states; in the form of a half-opened butterfly for Li 2 PS + (a triplet) and Li 2 SCl +

The LiBH₄-LiI Solid Solution as an Electrolyte in an All-Solid-State Battery

DEFF Research Database (Denmark)

Sveinbjörnsson, Dadi Þorsteinn; Christiansen, Ane Sælland; Viskinde, Rasmus

2014-01-01

The charge and discharge performance of an all-solid-state lithium battery with the LiBH4-LiI solid solution as an electrolyte is reported. Lithium titanate (Li4Ti5O12) was used as the positive electrode and lithium metal as the negative electrode. The performance of the all-solid-state cell...

Lithium Titanate Ceramic System as Electronic and Li-ion Mixed Conductors for Cathode Matrix in Lithium-Sulfur Battery

OpenAIRE

Ogihara, Hideki

2012-01-01

Lithium-Titanat-Spinell Li4/3Ti5/3O4, Ramsdellit Li2Ti3O7, und Spinell - Steinsalz abgeleitet Li4/3+xTi5/3O4 (0 kleiner/gleich x kleiner/gleich 1) wurden untersucht, um ein gemischtes (d.h. Li-Ionen und Elektronen) leitendes keramisches Material als eine Kathode-Matrix für alle Festköper-Lithium-Schwefel-Batterie zu entwickeln.

Preparation of Ti3C2 and Ti2C MXenes by fluoride salts etching and methane adsorptive properties

Science.gov (United States)

Liu, Fanfan; Zhou, Aiguo; Chen, Jinfeng; Jia, Jin; Zhou, Weijia; Wang, Libo; Hu, Qianku

2017-09-01

Here we reported the preparation of Ti3C2 MXene and Ti2C MXene by etching Ti3AlC2 and Ti2AlC with various fluoride salts in hydrochloric acid (HCl), including lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), and ammonium fluoride (NH4F). As-prepared Ti2C was further delaminated by urea, dimethylsulfoxide or ammonium hydroxide. Based on theoretical calculation and XPS results, the type of positive ions (Li+, Na+, K+, or NH4+) in etchant solution affect the surface structure of prepared MXene, which, in turn, affects the methane adsorption properties of MXene. The highest methane adsorption capacity is 8.5 cm3/g for Ti3C2 and 11.6 cm3/g for Ti2C. MXenes made from LiF and NH4F can absorb methane under high pressure and can keep methane under normal pressure, these MXenes may have important application on capturing methane or other hazardous gas molecules. MXenes made from NaF and KF can absorb methane under high pressure and release methane under low pressure. They can have important application in the adsorb storage of nature gas.

700 F hybrid capacitors cells composed of activated carbon and Li4Ti5O12 microspheres with ultra-long cycle life

Science.gov (United States)

Ruan, Dianbo; Kim, Myeong-Seong; Yang, Bin; Qin, Jun; Kim, Kwang-Bum; Lee, Sang-Hyun; Liu, Qiuxiang; Tan, Lei; Qiao, Zhijun

2017-10-01

To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li4Ti5O12 anodes. Microspherical Li4Ti5O12 (M-LTO) synthesized by spray-drying features 200-400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g-1), good rate capabilities (148 mAhh g-1 at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg-1, a maximum power density of 2466 W kg-1, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.

Bubble formation in irradiated Li2O

International Nuclear Information System (INIS)

Verrall, R.A.; Rose, D.H.; Miller, J.M.; Hastings, I.J.; MacDonald, D.S.

1991-01-01

Lithium oxide, irradiated to a burnup of 1 at% (total lithium) at temperatures between 400 and 850deg C with on-line tritium recovery and measurement, has been examined out-reactor. Residual tritium content ranged from 2.4 to 16 mCi/g, but, conservatively, averaged less than 10 mCi/g or 1 wppm. Scanning electron microscopy showed bubble formation in the ceramic which is thought to be due to helium formed from the in-reactor 6 Li(n, α) 3 H reaction. (orig.)

Structural characterization and electrochemical behaviour of Li{sub (4−x)/3}Ti{sub (5−2x)/3}Mn{sub x}O{sub 4} solid solution with spinel-structure

Energy Technology Data Exchange (ETDEWEB)

Martín, P., E-mail: pmartinp@quim.ucm.es; López, M.L.; Pico, C.; Veiga, M.L.

2013-07-15

A series of new oxides Li{sub (4−x)/3}Ti{sub (5−2x)/3}Mn{sub x}O{sub 4} (0.1 ≤ x ≤ 0.9) have been synthesized by solid state reactions and characterized by thermal analysis and X-ray and neutron diffraction. In all phases, Li{sup +} cations mainly occupy tetrahedral sites and transition metals cations are located on the octahedral ones. These phases show a structural disorder–order transition associated to the proportion of manganese in the samples and to its oxidation state. All these factors have a marked influence on the electrochemical properties and the phase x = 0.1 shows the best characteristics to be used as anode in a solid state battery. - Highlights: • Lithium spinels anodes in batteries. • Influence of Ti/Mn ratio in the electrochemical behaviour. • Li{sub 1.3}Ti{sub 1.6}Mn{sub 0.1}O{sub 4}: a promising zero-strain material. • Influence of disorder–order transitions on the physical properties.

Fetal deficiency of Lin28 programs life-long aberrations in growth and glucose metabolism

Science.gov (United States)

Shinoda, Gen; Shyh-Chang, Ng; de Soysa, T. Yvanka; Zhu, Hao; Seligson, Marc T.; Shah, Samar P.; Abo-Sido, Nora; Yabuuchi, Akiko; Hagan, John P.; Gregory, Richard I.; Asara, John M.; Cantley, Lewis C.; Moss, Eric G.; Daley, George Q.

2013-01-01

LIN28A/B are RNA binding proteins implicated by genetic association studies in human growth and glucose metabolism. Mice with ectopic over-expression of Lin28a have shown related phenotypes. Here we describe the first comprehensive analysis of the physiologic consequences of Lin28a and Lin28b deficiency in knockout (KO) mice. Lin28a/b-deficiency led to dwarfism starting at different ages, and compound gene deletions showed a cumulative dosage effect on organismal growth. Conditional gene deletion at specific developmental stages revealed that fetal but neither neonatal nor adult deficiency resulted in growth defects and aberrations in glucose metabolism. Tissue-specific KO mice implicated skeletal muscle-deficiency in the abnormal programming of adult growth and metabolism. The effects of Lin28b KO can be rescued by Tsc1 haplo-insufficiency in skeletal muscles. Our data implicate fetal expression of Lin28a/b in the regulation of life-long effects on metabolism and growth, and demonstrate that fetal Lin28b acts at least in part via mTORC1 signaling. PMID:23666760

Assessment of CaSO{sub 4}:Dy and LiF:Mg,Ti thermoluminescent dosimeters performance in the dosimetry of clinical electron beams; Avaliacao do desempenho dos detectores termoluminesncetes de CaSO{sub 4}:Dy e LiF:Mg,Ti na dosimetria de feixes clinicos de eletrons

Energy Technology Data Exchange (ETDEWEB)

Nunes, Maira Goes

2008-07-01

The assessment of the performance of CaS0{sub 4}:Dy thermoluminescent detectors produced by IPEN in the dosimetry of clinical electron beams aims to propose an alternative to the LiF:Mg,Ti commercial dosimeters (TLD-100) largely applied in radiation therapy. The two types of thermoluminescent dosimeters were characterised with the use of PMMA, RMI-457 type solid water and water phantoms in radiation fields of 4, 6, 9, 12 and 16 MeV electrons of nominal energies in which the dose-response curves were obtained and the surface and depth doses were determined. The thermoluminescent response dependency with the electron nominal energies and the applied phantom were studied. The CaS0{sub 4}:Dy presented the same behaviour than the LiF:Mg,Ti in such a way that its application as an alternative to the TLD-100 pellets in the radiation therapy dosimetry of electron beams is viable and presents the significantly higher sensitivity to the electron radiation as its main advantage. (author)

In vitro expansion of Lin+ and Lin− mononuclear cells from human peripheral blood

International Nuclear Information System (INIS)

Norhaiza, H. Siti; Zarina, Z. A. Intan; Hisham, Z. A. Shahrul; Rohaya, M. A. W.

2013-01-01

Haematopoietic stem cells (HSCs) are used in the therapy of blood disorders due to the ability of these cells to reconstitute haematopoietic lineage cells when transplanted into myeloablative recipients. However, substantial number of cells is required in order for the reconstitution to take place. Since HSCs present in low frequency, larger number of donor is required to accommodate the demand of transplantable HSCs. Therefore, in vitro expansion of HSCs will have profound impact on clinical purposes. The aim of this study was to expand lineage negative (Lin − ) stem cells from human peripheral blood. Total peripheral blood mononuclear cells (PBMNCs) were fractionated from human blood by density gradient centrifugation. Subsequently, PBMNCs were subjected to magnetic assisted cell sorter (MACS) which depletes lineage positive (Lin + ) mononuclear cells expressing lineage positive markers such as CD2, CD3, CD11b, CD14, CD15, CD16, CD19, CD56, CD123, and CD235a to obtained Lin − cell population. The ability of Lin + and Lin − to survive in vitro was explored by culturing both cell populations in complete medium consisting of Alpha-Minimal Essential Medium (AMEM) +10% (v/v) Newborn Calf Serum (NBCS)+ 2% (v/v) pen/strep. In another experiment, Lin + and Lin − were cultured with complete medium supplemented with 10ng/mL of the following growth factors: stem cell factor (SCF), interleukin (IL)-3, granulocyte-macrophage colony stimulating factor (GM-CSF), 2IU/mL of Erythropoietin (Epo) and 20ng/mL of IL-6. Three samples were monitored in static culture for 22 days. The expansion potential was assessed by the number of total viable cells, counted by trypan blue exclusion assay. It was found that Lin + mononuclear cells were not able to survive either in normal proliferation medium or proliferation medium supplemented with cytokines. Similarly, Lin − stem cells were not able to survive in proliferation medium however, addition of cytokines into the proliferation

Thermodynamics of irreversible structural transformation in Raddlesden-Popper perovskite-like layered Li-containing phases

International Nuclear Information System (INIS)

Reznitskij, L.A.

2001-01-01

The parameters of crystal units of the perovskite-like layer La 2 La 0.833 Nb 1.5 Ti 0.5 O 7 , Li 2 La 1.78 Nb 0.66 Ti 2.34 O 10 , Li 2 Sr 1.5 Nb 3 O 10 and Li 2 La 2.25 Nb 1.25 Ti 2.75 O 13 compounds ranked among the Raddlesden-Popper phases of the general formula Li 2 La x Nb 2n-3x Ti 3x-n O 3n+1 (n = 2, 3, 4; x = 0.833, 1.78, 2.25 correspondingly) and Li 2 Sr 1.5 Nb 3-x Fe x O 10-x (n = 3, x = 0) are shown before and after investigation by means of high resolution electron microscopy. Calculated volumes of formula units, changes in volumes after transformation, evaluations of specific heat C p of the compounds are demonstrated. Changing of transformation entropies, enthalpies and Gibbs energies of monotropic structural transformation were calculated [ru

TiO2 aerogel–metal organic framework nanocomposite: a new class ...

Indian Academy of Sciences (India)

2018-02-05

Feb 5, 2018 ... titanium dioxide in association with a monolayer of dye molecules is .... Zn–MOF has not affected the anatase phase formation of. TiO2 crystals ..... [15] Xin X, Scheiner M, Ye M and Lin Z 2011 Langmuir 27 14594. [16] Kim B ...

Study of T L LiF: Mg,Ti (Model JR1152C) material for its use in the environmental monitoring; Estudio del material TL LiF: Mg, Ti (JR1152C) para su empleo en el monitoreo ambiental

Energy Technology Data Exchange (ETDEWEB)

Molina P, D.; Diaz B, E.; Prendes A, M. [Centro de Proteccion e Higiene de las Radiaciones, CPHR, Apdo. postal 6195, Habana 6, CP 10600, Ciudad Habana (Cuba)

1999-07-01

In order to evaluate the possibility to use the T L material of LiF: Mg,Ti (Model JR1152C) as environmental dosemeter it was realized its characterization of it according to the established criterion in the standard IEC-1066. The properties studied were: homogeneity of the lot, reproducibility, response linearity, detection threshold, auto irradiation, residual signal, response pride (fading) and angular dependence. The results prove the compliment of the IEC requirements and therefore the applicability of this dosemeter in the environmental monitoring. (Author)

Structure and Dielectric Properties of (Sr0.2Ca0.488Nd0.208) TiO3-Li3NbO4 Ceramic Composites

Science.gov (United States)

Xia, C. C.; Chen, G. H.

2017-12-01

The new ceramic composites of (1-x) Li3NbO4-x (Sr0.2Ca0.488Nd0.208)TiO3 were prepared by the conventional solid state reaction method. The sintering behavior, phase composition, microstructure and microwave dielectric properties of the ceramics were investigated specially. The SEM and XRD results show that (1-x) Li3NbO4-x (Sr0.2Ca0.488Nd0.208) TiO3 (0.35≤x≤0.5) composites were composed of two phase, i.e. perovskite and Li3NbO4. With the increase of x, the ɛr increases from 27.1 to 38.7, Q×f decreases from 55000 GHz to 16770 GHz, and the τ f increases from -49 ppm/°C to 226.7 ppm/°C. The optimized dielectric properties with ɛr∼31.4, Q×f~16770GHz and τf~-8.1ppm/°C could be obtained as x=0.4 sintered at 1100°C for 4h. The as-prepared ceramic is expected to be used in resonators, filters, and other microwave devices.

Study of the Unbound Nuclei $^{10}$Li and $^{7}$He at REX ISOLDE

CERN Multimedia

2002-01-01

% IS367\\\\ \\\\ We propose to study the two unbound nuclei $^{10}$Li and $^{7}$He produced in simple one-neutron pick-up reactions induced by intense beams of $^{9}$Li and $^{6}$He from REX ISOLDE in $^{9}$Be and CD$_{2}$ targets.\\\\ \\\\The unbound nucleus $^{10}$Li is a binary subsystem of the two-neutron halo nucleus $^{11}$Li and its structure is of key importance for theoretical investigations of the halo structure. We propose two different reactions, which together would give an unambiguous determination of lowest $\\textit{s-}$ and $\\textit{p-}$wave resonances in the ($^{9}$Li+n) system.\\\\ \\\\Similarly $^{7}$He plays an important role in the dissociation of $^{8}$He, a drip-line nucleus with an $\\alpha$+4n five-body structure. The aim of our investigation is to search for an excited 1/2$^{-}$ state above the $^{7}$He 3/2$^{-}$ ground state in order to investigate its cluster structure. \\\\ \\\\

Lin Receives 2010 Natural Hazards Focus Group Award for Graduate Research

Science.gov (United States)

2010-11-01

Ning Lin has been awarded the Natural Hazards Focus Group Award for Graduate Research, given annually to a recent Ph.D. recipient for outstanding contributions to natural hazards research. Lin's thesis is entitled “Multi-hazard risk analysis related to hurricanes.” She is scheduled to present an invited talk in the Extreme Natural Events: Modeling, Prediction, and Mitigation session (NH20) during the 2010 AGU Fall Meeting, held 13-17 December in San Francisco, Calif. Lin will be formally presented with the award at the Natural Hazards focus group reception on 14 December 2010.

Magnetostriction in composites of LiFe5O8-BaTiO3

International Nuclear Information System (INIS)

Sarah, P.; Suryanarayana, S.V.

2003-01-01

Polycrystalline lithium ferrite, LiFe 5 O 8 was prepared by adopting two preparation techniques, the solid-state double sintering method and the sol-gel method. This ferrite powder was thoroughly mixed with barium titanate, BaTiO 3 for preparation of di-phasic composites of lithium ferrite and barium titanate. X-ray diffraction study of these composites revealed the presence of both the phases. Magnetostriction of these composites was measured in varying magnetic fields. The value of magnetostriction for the composites prepared by the sol-gel method was found to be higher than the values obtained in case of composites prepared by the solid-state method. Magnetostriction was found to decrease with increasing content of barium titanate. The saturation field was found to increase with the introduction of barium titanate

High rate performance of the carbon encapsulated Li4Ti5O12 for lithium ion battery

Science.gov (United States)

Cheng, Qi; Tang, Shun; Liang, Jiyuan; Zhao, Jinxing; Lan, Qian; Liu, Chang; Cao, Yuan-Cheng

Li4Ti5O12 (LTO) is attractive alternative anode material with excellent cyclic performance and high rate after coating modifications of the conductive materials. Anatase TiO2 and glucose were applied of the synthesis of the carbon coated LTO (C@LTO). XRD results showed that all the major diffractions from the spinel structure of LTO can be found in the C@LTO such as (1 1 1), (3 1 1), (4 0 0) but there are no observations of the Carbon diffraction peaks. Electrochemical Impedance Spectroscopy (EIS) data shows C@LTO resistance was nearly half of the LTO value. Rate performance showed that capacity of C@LTO was higher than that of the pure LTO from 0.1 C, 0.2 C, 1 C, 2 C, 5 C and 10 C, which indicates that this is a promising approach to prepare the high performance LTO anode.

Graphene supported Li{sub 2}SiO{sub 3}/Li{sub 4}Ti{sub 5}O{sub 12} nanocomposites with improved electrochemical performance as anode material for lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Wang, Qiufen, E-mail: grp2009wqf@163.com; Yang, Shuai; Miao, Juan, E-mail: miaojuan@hpu.edu.cn; Lu, Mengwei; Wen, Tao; Sun, Jiufang

2017-05-01

Highlights: • We synthesized Graphene supported Li{sub 2}SiO{sub 3}@Li{sub 4}Ti{sub 5}O{sub 12}. • The discharge capacity is 399.2 mAh g{sup −1} at the current density of 150 mA g{sup −1} after 200 cycles. • The charge rate capacities retain 89.1% at the current density from 150 mA g{sup −1} to 750 mA g{sup −1}. • The recovery rates of the charge capacities are 91.0% when returned the current density of 150 mA g{sup −1}. - Abstract: Graphene supported Li{sub 2}SiO{sub 3}@Li{sub 4}Ti{sub 5}O{sub 12} (GE@LSO/LTO) nanocomposites have been synthesized via a hydrothermal route and following calcination. LSO/LTO nanospheres are adhered to the graphene nanosheets with the size of 50–100 nm, in which both LSO and LTO particles are attached together. When tested as the anode for lithium ion batteries, the initial discharge and charge capacities of GE@LSO/LTO are 720.6 mAh g{sup −1} and 463.4 mAh g{sup −1} at the current density of 150 mA g{sup −1}. After 200 cycles, the discharge and charge capacities can be remained of 399.2 mAh g{sup −1} and 398.9 mAh g{sup −1}, respectively. Moreover, the charge rate capacities of GE@LSO/LTO composites retain 89.1% at the range of current density from 150 mA g{sup −1} to 750 mA g{sup −1}. And its recovery rates are 91.0% when the current density back to 150 mA g{sup −1}. In addition, the reversible capacity and cycle stability of GE@LSO/LTO are better than that of LTO and LSO/LTO. The reasons can be attributed to the synergistic effect between GE and LSO/LTO as well as the features of GE supports.