机械载荷作用对车用动力电池的安全性具有重要影响，其中挤压变形是导致车 用动力电池发生短路失效的重要因素之一． 从方形磷酸铁锂电池的详细结构和内部短路 失效机理出发，分别对电池整体和局部受压两种典型的挤压载荷进行试验，并结合其力 － 变形响应、电压和温度的变化关系分析电池的失效特征． 建立方形磷酸铁锂电池内芯的新 型本构方程和电池的有限元模型，对平面挤压和局部压痕载荷下电池的变形响应进行数 值分析． 结果表明，所建立的模型合理地表征了磷酸铁锂电池在挤压条件下的基本力学特 性，并且能够预测局部受压形式下电池内部短路的发生时刻和失效位置． 研究为方形磷酸 铁锂电池在机械载荷条件下的变形响应特性和电池内部短路失效分析提供了参考，对提 高电动汽车动力电池的机械安全性具有实际的工程意义． 

 Mechanical load has an important influence on the safety of vehicle battery and compression deformation is a key factor of internal short circuit battery failure． Accordingly，detailed structure and internal short circuit mechanism of LiFeO4 cells，plane compression and local indentation tests were performed on the cells． Ｒesponse of load-deformation，voltage and temperature changing relationship of the cell under compression loading conditions were obtained and failure feature was analyzed． Then constitutive equation and finite element model of LiFeO4 cell were established． Deformation of the cell under plane compression and local indentation condition was analyzed by simulation． The results showed that the model can correctly reflect basic mechanical property of LiFeO4 battery under compression loading conditions，and that internal short circuit onset time and failure location of the cell under