硅酸盐学报2013，Vol.41Issue(2)：165-170,6.DOI:10.7521/j.issn.0454-5648.2013.02.08
锂离子电池正极材料Li3V2[(PO4)1-xFx]3/C的合成及性能表征
Synthesis and Characterization of Li3V2[(PO4)1-xFx]3/C as Cathode Materials for Lithium Ion Batteries
摘要
Abstract
Single phase Li3V2[(PO4)1-xFx]3/C (x =0,0.02,0.05,0.08,0.10 and 0.15) samples were synthesized by a carbothermal reduction method using LiH2PO4,LiF and V2O5 as raw materials and sucrose as a reductive agent.The structure and performance of the samples with respect to effect ofF--doping were determined by X-ray diffraction,cyclic voltammetry and electrochemical impedance spectroscopy,respectively.The results indicate that the F-substituted Li3V2(PO4)3/C has the same monoclinic structure as the Li3V2(PO4)3/C.According to the electrochemical analysis,the Li3V2[(PO4)0.95F0.05]3/C sample exhibits a better electrochemical performance with the initial specific discharge capacity of 124.4 mA·h/g and capacity retention rate of 98.5％ after 50 cycles at 0.5 C in the voltage range from 3.0 to 4.2V (vs.Li/Li+).At 15 C in the voltage range from 3.0 to 4.2V (vs.Li/Li+),Li3V2[(PO4)0.95F0.05]3/C delivers an initial capacity of 84.7 mA·h/g and capacity retention rate of 97.4％ after 50 cycles,and the Li3V2(PO4)3/C presents the initial capacity of 59.2 mA·h/g and capacity retention rate of 89.0％.The improved rate and cycle performance could be attributed to the enhanced electrode reaction reversibility/electronic conductivity and the decreased charge transfer resistances by appropriate doping F-concentration.The improved electrochemical performance of Li3V2[(PO4)0.95F0.05]3/C cathode material could be used for its commercial application.关键词
锂离子电池/正极材料/磷酸钒锂/电化学性能Key words
lithium ion battery/ cathode material/ lithium vanadium phosphate/ electrochemical characterization分类
信息技术与安全科学引用本文复制引用
龙云飞,苏静,李媚林,王凡,吕小艳,文衍宣..锂离子电池正极材料Li3V2[(PO4)1-xFx]3/C的合成及性能表征[J].硅酸盐学报,2013,41(2):165-170,6.基金项目
广西自然科学基金(2011GXNSFA018015)资助项目. （2011GXNSFA018015）
