碳源对Li3V2(PO4)3正极材料性能的影响

采用高温碳热还原法在惰性气氛下合成单斜晶型Li3V2(PO4)3正极材料,考察活性炭、蔗糖和酚醛树脂等不同碳源对目标材料性能的影响。采用XRD、FE-SEM和电化学测试等手段对目标材料进行结构表征和性能测试。结果显示,以酚醛树脂作为碳源的正极材料具有优良的电化学性能,首次放电比容量达138 mA.h/g,到第10次循环容量降至122.9 mA.h/g。酚醛树脂作碳源能在加热的过程中固化交联成三维的网状结构,极有效地限制了粒子的进一步长大,材料粒径最小。

Effects of Carbon Sources on Performance of Li3V2(PO4)3 Cathode Material

Monoclinic Li3V2(PO4)3 cathode materials are synthesized by carbo-thermal reduction in high temperature with protection of inert gas.The effects of different carbon sources,such as active carbon,sucrose and phenolic resin,on the performance of synthesized cathode materials are investigated.The crystal structure and the electrochemical performance are characterized by XRD,FE-SEM,and electrochemical performance testing.The results show that the cathode material synthesized with phenolic resin is of the most excellent electrochemical performances.The initial discharge specific capacity is 138 mA·h/g at room temperature and C/10 discharge rate.After 10 cycles,the discharge capacity remains 122.9 mA·h/g.The phenolic resin is gradually solidified when it is heated,and the cross-linked structure formed,so the growth of active particles is effectively restricted.As a result,the Li3V2(PO4)3 cathode materials synthesized with phenolic resin exhibits the least particle size.