磷酸铁锂锂离子电池在45℃下的循环失效分析  

Cycle failure analysis of lithium iron phosphate Li-ion battery at 45℃

作　　者：王跃冰 杜智锋 杨大鹏 WANG Yuebing;DU Zhifeng;YANG Dapeng(China Lithium Battery Technology(Luoyang)Co.,Ltd.,Luoyang 471000,Henan,China)

机构地区：[1]中航锂电(洛阳)有限公司,河南洛阳471000

出　　处：《电池》2025年第1期32-36,共5页Battery Bimonthly

摘　　要：锂离子电池的循环寿命会随温度的升高而缩短。研究磷酸铁锂(LiFePO_(4))/石墨软包装电池在45℃下的老化机理,对比常温(25℃)和45℃下的容量变化,发现健康状态(SOH)衰减至85%时,45℃循环寿命仅为常温的1/3。拆解不同SOH的电池,发现在循环后负极材料会出现膨胀,固体电解质相界面(SEI)膜增厚并在表面发生锂盐的沉积。单片半电池的测试表明:常温容量衰减的主要原因是活性锂的不可逆损失;高温容量衰减的主要原因还有正极材料结构的衰退。The cycle life of Li-ion battery decreases with increasing temperature.Aging mechanism of lithium iron phosphate(LiFePO_(4))/graphite pouch battery at 45℃is investigated,the capacity changes at normal temperature(25℃)and 45℃are compared,it is found that 45℃cycle life is only 1/3 of the normal temperature when the state of health(SOH)decays to 85%.Batteries at different SOH are disassembled and it is found that the anode electrode material swells after cycle aging,the solid electrolyte interface(SEI)film thickens and lithium salt deposition occurs on the surface.The test of single half-cells shows that the main cause of capacity degradation at normal temperature is the irreversible loss of active lithium,while the main cause of capacity degradation at high temperatures also includes the degradation of the structure of the cathode material.

关 键 词：磷酸铁锂(LiFePO_(4)) 老化 固体电解质相界面(SEI)膜 活性锂 不可逆损失 锂离子电池 循环失效 

分 类 号：TM912.9[电气工程—电力电子与电力传动]