充电电压上限对磷酸亚铁锂电化学性能的影响  

Influence of charge voltage upper limit on electrochemical performance of LiFePO_4 cathode

作　　者：郑洪河[1] 张晓丽[1] 张玉玺[1] 

机构地区：[1]河南师范大学化学与环境科学学院,河南新乡453002

出　　处：《电源技术》2010年第1期32-34,共3页Chinese Journal of Power Sources

基　　金：国家自然科学基金(20573033)

摘　　要：使用循环伏安、恒电流充放电、交流阻抗方法研究了充电电压上限对橄榄石型正极材料磷酸亚铁锂的电化学嵌脱锂性质行为的影响。发现在3.5～4.5V的范围内,充电电压上限对磷酸亚铁锂的放电比容量影响不大,但高电位条件下易于引发电极过程的副反应,造成电极界面电阻增长,对电极的倍率性能不利。充电电压上限控制在3.7～3.9V之间电极表现出最佳的电化学性能。The influence of charge voltage upper limit on the electrochemical performance of LiFePO4 cathode was studied by cycling voltammetry,galvanostatic charge-discharge and AC impedance techniques. Little effect of upper voltage limit was observed on the specific capacity in the range of 3.5-4.5 V. However, side reactions were induced when the electrode was charged to higher upper voltage limit up to 4.1 V, which resulted in the increase of the electrode resistance that spoiled the rate capability of the olivine LiFePO4 electrode. The electrochemical performance is the best when the voltage upper limit is between 3.7 V and 3.9 V.

关 键 词：锂离子电池 充电电压 LIFEPO4 电化学性能 

分 类 号：TM912.2[电气工程—电力电子与电力传动]