Effects of Ta Ion Doping on Structure and Electrochemical Performances of Li3V2(PO4)3/C Cathode Materials

2012 ◽  
Vol 519 ◽  
pp. 137-141 ◽  
Author(s):  
Lei Zhang ◽  
Tao Yang ◽  
Qian Yang ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
...  
Keyword(s):  
Particle Size ◽  
Cathode Materials ◽  
Discharge Rate ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Physical Structure ◽  
Undoped Sample ◽  
Electrochemical Performances ◽  
Ion Doping ◽  
Method Effects

Ta-doped Li3V2(PO4)3 cathode material coated by carbon was synthesized via a sol-gel method. Effects of Ta5+ doping on the physical structure and electrochemical performances of the Li3V2(PO4)3/C cathode materials were investigated. Compared with the undoped sample, the Ta-doped samples had no excess peaks but the larger particle size and the narrower distribution of the particle size, indicating that Ta5+ entered into the structure of (Li1-5xTax)3V2(PO4)3/C rather than forming any impurities. When x was up to 0.01, the best electrochemical properties of the Ta-doped cathode materials had been displayed at the charge and discharge rate of 0.1C with the voltage of 3.0～4.8V. The analysis of cyclic voltammetry revealed that the polarization of the Li3V2(PO4)3/C cathode materials could be effectively decreased by Ta5+ doping(x=0.01), mainly resulting from the better electronic conductivity.

Effect of ion doping on the electrochemical performances of LiFePO4–Li3V2(PO4)3 composite cathode materials

RSC Advances ◽  
2014 ◽  
Vol 4 (30) ◽  
pp. 15332-15339 ◽  
Author(s):  
Chao Jin ◽  
Xudong Zhang ◽  
Wen He ◽  
Yan Wang ◽  
Haiming Li ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Composite Cathode ◽  
Electrochemical Performances ◽  
Ion Doping

This review highlights the effect of ion doping on the electrochemical performances of LiFePO4–Li3V2(PO4)3 composite cathode materials.

FACILE SOL–GEL SYNTHESIS OF Li[Li0.2Mn0.56Ni0.16Co0.08]O2 AS IMPROVED CATHODE MATERIAL FOR LITHIUM-ION BATTERIES

2013 ◽  
Vol 01 (04) ◽  
pp. 1340015
Author(s):  
WENJUAN HAO ◽  
HAN CHEN ◽  
YANHONG WANG ◽  
HANHUI ZHAN ◽  
QIANGQIANG TAN ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Sol Gel ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Electrochemical Performances ◽  
Acetate Tetrahydrate ◽  
Li Ion Batteries ◽  
Gel Method ◽  
Sol Gel Method ◽  
Li Ion

Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 cathode materials for Li -ion batteries were synthesized by a facile sol–gel method followed by calcination at various temperatures (700°C, 800°C and 900°C). Lithium acetate dihydrate, manganese (II) acetate tetrahydrate, nickel (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate are employed as the metal precursors, and citric acid monohydrate as the chelating agent. For the obtained Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 materials, the metal components existed in the form of Mn 4+, Ni 2+ and Co 3+, and their molar ratio was in good agreement with 0.56 : 0.16 : 0.08. The calcination temperature played an important role in the particle size, crystallinity and further electrochemical properties of the cathode materials. The Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 material calcined at 800°C for 6 h showed the best electrochemical performances. Its discharge specific capacities cycled at 0.1 C, 0.5 C, 1 C and 2 C rates were 266.0 mAh g−1, 243.1 mAh g−1, 218.2 mAh g−1 and 192.9 mAh g−1, respectively. When recovered to 0.1 C rate, the discharge specific capacity was 260.2 mAh g−1 and the capacity loss is only 2.2%. This work demonstrates that the sol–gel method is a facile route to prepare high performance Li [ Li 0.2 Mn 0.56 Ni 0.16 Co 0.08] O 2 cathode materials for Li -ion batteries.

scholarly journals Complexing Agents on Carbon Content and Lithium Storage Capacity of LiFePO4/C Cathode Synthesized via Sol-Gel Approach

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
C. Guan ◽  
H. Huang
Keyword(s):  
Discharge Rate ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cost Effective ◽  
Reversible Capacity ◽  
Complexing Agents ◽  
Lithium Storage ◽  
Synthesis Conditions

Olivine-structured LiFePO4faces its intrinsic challenges in terms of poor electrical conductivity and lithium-ion diffusion capability for application to lithium-ion batteries. Cost-effective sol-gel approach is advantageous to in situ synthesize carbon-coated LiFePO4(LiFePO4/C) which can not only improve electronic conductivity but also constrain particle size to nanometer scale. In this study, the key parameter is focused on the choice and amount of chelating agents in this synthesis route. It was found that stability of complexing compounds has significant impacts on the carbon contents and electrochemical properties of the products. At the favorable choice of precursors, composition, and synthesis conditions, nanocrystalline LiFePO4/C materials with appropriate amount of carbon coating were successfully obtained. A reversible capacity of 162 mAh/g was achieved at 0.2Crate, in addition to good discharge rate capability.

ChemInform Abstract: Effect of Ion Doping on the Electrochemical Performances of LiFePO4-Li3V2(PO4)3Composite Cathode Materials

ChemInform ◽  
2014 ◽  
Vol 45 (35) ◽  
pp. no-no
Author(s):  
Chao Jin ◽  
Xudong Zhang ◽  
Wen He ◽  
Yan Wang ◽  
Haiming Li ◽  
...  
Keyword(s):  
Cathode Materials ◽  
Electrochemical Performances ◽  
Ion Doping

scholarly journals Preparation and Characterisation of LiFePO4/CNT Material for Li-Ion Batteries

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Rushanah Mohamed ◽  
Shan Ji ◽  
Vladimir Linkov
Keyword(s):  
Carbon Nanotubes ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
High Efficiency ◽  
Discharge Rate ◽  
Composite Cathode ◽  
Electrochemical Performances ◽  
Li Ion Batteries ◽  
Li Ion ◽  
Cycle Efficiency

Li-ion battery cathode materials were synthesised via a mechanical activation and thermal treatment process and systematically studied. LiFePO4/CNT composite cathode materials were successfully prepared from LiFePO4material. The synthesis technique involved growth of carbon nanotubes onto the LiFePO4using a novel spray pyrolysis-modified CVD technique. The technique yielded LiFePO4/CNT composite cathode material displaying good electrochemical activity. The composite cathode exhibited excellent electrochemical performances with 163 mAh/g discharge capacity with 94% cycle efficiency at a 0.1 C discharge rate in the first cycle, with a capacity fade of approximately 10% after 30 cycles. The results indicate that carbon nanotube addition can enable LiFePO4to display a higher discharge capacity at a fast rate with high efficiency. The research is of potential interest for the application of carbon nanotubes as a new conducting additive in cathode preparation and for the development of high-power Li-ion batteries for hybrid electric vehicles.

A Novel Synthesis of Nanometer Spherical β-Ni(OH)2 Cathode Materials with High Electrochemical Performances

2014 ◽  
Vol 936 ◽  
pp. 491-495
Author(s):  
Li Chen ◽  
Yan Ming Wang ◽  
Juan Liu ◽  
Xing Yao Wang
Keyword(s):  
Particle Size ◽  
Cathode Materials ◽  
Specific Capacity ◽  
Naphthenic Acid ◽  
Electrochemical Performances ◽  
Small Particle Size ◽  
Capacity Retention ◽  
Novel Synthesis ◽  
Loaded Organic Phase ◽  
Xrd And Tem

A novel hydrothermal stripping technique synthesis route, in which the nickel-loaded organic phase of naphthenic acid was directly stripped by water at 140-240 °C for 2.0 h to recover nickel as hydroxide precipitates, has been firstly developed. The nickel hydroxide powders synthesized by this route was the spherical β-Ni(OH)2 and had a small particle size in the range of 20-100 nm shown by XRD and TEM test. The results of electrochemical performances show that the nanometer β-Ni(OH)2 cathode materials have much higher discharge specific capacity, excellent capacity retention and cycle performances.

Effect of Heat Treatment on Charge-Discharge Property of Fluoride Cathode Materials for Li Ion Secondary Batteries

2013 ◽  
Vol 566 ◽  
pp. 131-134 ◽  
Author(s):  
Yasumasa Tomita ◽  
Jinta Kato ◽  
Yoshiumi Kohno ◽  
Yasuhisa Maeda ◽  
Kenkichiro Kobayashi
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Cathode Materials ◽  
Mechanical Milling ◽  
Fine Particle ◽  
Discharge Rate ◽  
Milling Process ◽  
Li Ion ◽  
Discharge Measurements ◽  
Charge Discharge

ron fluoride (III) anhydrate fine particle was prepared by drying in vacuum from FeF3·3H2O, a mechanical milling process and a calcination at 473 773 K. Particle size of FeF3·3H2O was ca. 3 5 μm and that of FeF3 anhydrate was 100 500 nm after drying and milling. FeF3 sample only after drying and milling was hygroscopic and became FeF3·3H2O under atmosphere. FeF3 became stable under atmosphere after oxidation at 673 K for more than 20 minutes. It was found that Fe2O3 was produced by calcination and covered the surface of FeF3 particles. In Charge-discharge measurements, the discharge capacity of these FeF3 samples was 150 - 200 mAh/g at a discharge rate of 0.1 C. The oxidation could improve the discharge properties of FeF3 cathode.

Synthesis and Characterization of LiFePO4/C Composite Obtained by One-Step Solid-State Reaction Using Solid PVA as Carbon Source

2009 ◽  
Vol 1170 ◽  
Author(s):  
Limei Yang ◽  
Guangchuan Liang ◽  
Li Wang ◽  
Xiaoke Zhi ◽  
Xiuqin Ou
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Carbon Source ◽  
Discharge Capacity ◽  
Cathode Materials ◽  
Solid State Reaction ◽  
Electronic Conductivity ◽  
Cycle Performance ◽  
High Electronic Conductivity ◽  
One Step

AbstractLiFePO4/C composite cathode materials were synthesized by one-step solid-state reaction using FePO4 as main raw materials and solid PVA (Polyvinyl Alcohol) as a reductive agent and carbon source. The sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), particle size analysis and charge-discharge test. The results indicated that the carbon generated from the pyrogenation of PVA did not affect the olivine structure of the cathode materials but considerably improved its high-rate discharge ability and cycle performance. The initial discharge capacity of the sample was 149.7, 133.1, 120.6, 93.0 mAh/g at 0.2C, 1C, 2C, 5C respectively, and the discharge capacity could reach 90 mAh/g at 5C rates after 80 cycles. It is believed that the carbon coating could lead to small particle size and high electronic conductivity of active materials, thus leading to excellent electrochemical performance of LiFePO4/C cathode materials.

scholarly journals Influence of particle size and fluorination ratio of CF x precursor compounds on the electrochemical performance of C–FeF2 nanocomposites for reversible lithium storage

2013 ◽  
Vol 4 ◽  
pp. 705-713 ◽  
Author(s):  
Ben Breitung ◽  
M Anji Reddy ◽  
Venkata Sai Kiran Chakravadhanula ◽  
Michael Engel ◽  
Christian Kübel ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrochemical Performance ◽  
Cathode Materials ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Lithium Storage ◽  
One Pot ◽  
Electrically Conductive ◽  
X Ray ◽  
Electron Energy Loss

Systematical studies of the electrochemical performance of CF x -derived carbon–FeF2 nanocomposites for reversible lithium storage are presented. The conversion cathode materials were synthesized by a simple one-pot synthesis, which enables a reactive intercalation of nanoscale Fe particles in a CF x matrix, and the reaction of these components to an electrically conductive C–FeF2 compound. The pretreatment and the structure of the utilized CF x precursors play a crucial role in the synthesis and influence the electrochemical behavior of the conversion cathode material. The particle size of the CF x precursor particles was varied by ball milling as well as by choosing different C/F ratios. The investigations led to optimized C–FeF2 conversion cathode materials that showed specific capacities of 436 mAh/g at 40 °C after 25 cycles. The composites were characterized by Raman spectroscopy, X-Ray diffraction measurements, electron energy loss spectroscopy and TEM measurements. The electrochemical performances of the materials were tested by galvanostatic measurements.

Electrochemical Performances of Li4-xKXTi5O12 (x=0.02, 0.04, 0.06) as Anode Materials for Lithium Ion Battery

2013 ◽  
Vol 712-715 ◽  
pp. 313-316 ◽  
Author(s):  
Gu Fang
Keyword(s):  
Anode Materials ◽  
Solution Method ◽  
Discharge Rate ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Cycling Performance ◽  
Electrochemical Process ◽  
Electrochemical Performances ◽  
X Ray Diffraction

Li4-xKxTi5O12 (x=0.02, 0.04, 0.06) were prepared via a solution method. The electrochemical performances including charge-discharge, rate property and cyclic voltammety were also investigated. The structure of the samples were characterized by X-ray diffraction. The results revealed that Li3.96K0.04Ti5O12 was well. K+ doping did not change the electrochemical process, instead enhanced the electronic conductivity and ionic conductivity. The reversible capacity and cycling performance were effectively improved.

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