陶瓷隔膜厚度对磷酸铁锂电池安全性的影响  

Effect of Ceramic Separator Thickness on the Safety of Phosphate Iron Lithium Battery

作　　者：刘伯峥 董世佳 于宝军 马洪运 曾涛[1] LIU Bozheng;DONG Shijia;YU Baojun;MA Hongyun;ZENG Tao(Tianjin Lishen Battery Joint-Stock Co.,Ltd.,Research and Development Center,Tianjin 300384,China)

机构地区：[1]天津力神电池股份有限公司研发中心,天津300384

出　　处：《武汉大学学报（理学版）》2023年第4期469-475,共7页Journal of Wuhan University:Natural Science Edition

基　　金：国家重点研发计划(2019YFC1907800);天津市科技计划(20YFYSGX00050)。

摘　　要：为识别隔膜轻薄化潜在的安全风险,采用方形铝壳磷酸铁锂动力电池系统地对比了(9+3)μm陶瓷隔膜(9CCS)与(7+3)μm陶瓷隔膜(7CCS)电池过放电、过充电、外部短路、加热、挤压和针刺安全性能。结果表明,隔膜变薄增加了电池的安全风险,相比9CCS隔膜,7CCS隔膜力学强度及抗热收缩性降低,安全测试表现为最高温升、电池阻抗及厚度明显增加,造成过充电热失控荷电态(SOC)提前7.2%,加热引发热失控的温度降低10℃,362 kN挤压发生热失控,针刺引起安全阀提前6 s开启,浓烟释放持续时间更长。本研究为开发更高能量密度动力电池的隔膜选择及体系、结构等优化改善提供了数据支撑。In order to identify the potential safety risks of lighter and thinner separator,the safety performance of(9+3)μm ceramic coated separator(9CCS)and(7+3)μm ceramic coated separator(7CCS)batteries were systematically compared in terms of over-discharge,overcharge,external short circuit,heat,crush,and nail penetration by using prismatic aluminum-shell phosphate iron lithium power battery.The results show that thinner separator increases the battery safety risks.Compared with 9CCS,the mechanical strength and heat shrinkage resistance of 7CCS are reduced.The battery safety test phenomena show that the maximum test temperature,battery resistance and thickness of the 7CCS batteries rise significantly,resulting in the 7.2% advance of thermal runaway(TR)state of charge(SOC)triggered by overcharge,the reduction of TR temperature about 10℃ triggered by heating,the occurrence of TR during 362 kN crush,the open of safety vent 6 s ahead of time caused by nail penetration,and the extension of smoke release time.This study provides data support for the development of higher energy density power battery in separator choice,system and structure optimization.

关 键 词：隔膜 磷酸铁锂 动力电池 安全性能 

分 类 号：TM912.9[电气工程—电力电子与电力传动]