Effect of Vanadium Substitution on Structure of Li₂FeSiO₄/C Composites

Authors

YANG Hong, Department of Materials Science & Engineering, College of Materials;
ZHANG Ying, Department of Materials Science & Engineering, College of Materials;Fujian Key Laboratory of Advanced Materials, Xiamen University, Xiamen, Fujian 361005, P.R. China;
CHENG Xuan, Department of Materials Science & Engineering, College of Materials;Fujian Key Laboratory of Advanced Materials, Xiamen University, Xiamen, Fujian 361005, P.R. China;Follow

Corresponding Author

CHENG Xuan(xcheng@xmu.edu.cn)

Abstract

The carbon coated lithium iron silicate (Li₂FeSiO₄/C) composites were prepared using less expansive iron starting material of soluble ferric nitrate through sol-gel process and solid state reaction. The theoretically calculated amounts of 5, 10, 15, 20, 25, 30, and 50% of vanadium (V) were introduced using NH₄VO₃ to obtain V-substituted Li2FeSiO4/C composites. It was found that the pure Li₂FeSiO₄/C composite exhibited a good crystallinity with P21/n and nearly no impurities being detected, while the V-substituted Li₂FeSiO₄/C composites showed major impurities of Li₂SiO₃ and V₃O₄/Fe₃O₄. The discharge capacities of 160.9 mAh·g^-1 and 130.8 mAh·g^-1 at C/16 were obtained for the pure and 5% V-substituted Li₂FeSiO₄/C composites, respectively. The degree of graphitization in amorphous carbon was enhanced and the quantities of carbon coated were lowered with the increase of V-substituted amounts. The electrochemical performance of 5% V-substituted Li₂FeSiO₄/C composite was not improved due to the presences of impurities which were directly linked to the amounts of V substitution.

Graphical Abstract

Keywords

lithium iron silicates, vanadium substitution, cathode materials, lithium ion battery

DOI Link

https://doi.org/10.13208/j.electrochem.130356

Publication Date

2013-12-28

Online Available Date

2013-12-23

Revised Date

2013-07-08

Received Date

2013-05-16

Recommended Citation

YANG Hong, ZHANG Ying, CHENG Xuan. Effect of Vanadium Substitution on Structure of Li₂FeSiO₄/C Composites[J]. Journal of Electrochemistry, 2013 , 19(6): 565-570.
DOI: 10.13208/j.electrochem.130356
Available at: https://jelectrochem.xmu.edu.cn/journal/vol19/iss6/10