软包磷酸铁锂电池低温热安全性能研究  

Low temperature thermal safety performance of soft packaged lithium iron phosphate battery

作　　者：王绥军[1] 傅凯[1] 官亦标[1] 刘曙光[1] 徐彬[1] 范茂松[1] 

机构地区：[1]中国电力科学研究院,北京100192

出　　处：《储能科学与技术》2016年第2期204-209,共6页Energy Storage Science and Technology

基　　金：国家电网科技项目(电动汽车充换电设施运行效能提升的关键技术研究)

摘　　要：本文以剩余容量接近80%的软包磷酸铁锂电池为研究对象,研究其在-10℃低温充放电循环后的安全性能。对低温和常温循环后的电池进行热失控实验分析,同时解剖电池并测试电池材料的锂元素含量和热稳定性能。测试结果表明,电池低温循环过程中容量急剧衰减,低温循环后电池热失控温度明显降低,低温循环过程中电池负极析出了锂单质,电池材料的热稳定性也发生了变化。另外,还对低温循环后的电池进行了满电状态下的常温搁置实验,实验过程中电池全部产生胀气现象,通过进一步测试分析发现,气体以CO和H_2为主。与新电池对比发现,剩余容量接近80%的软包磷酸铁锂电池低温下充放电循环更容易产生锂枝晶,造成其电化学性能发生严重的不可逆衰退,热失控温度明显提前,因此剩余容量接近80%的磷酸铁锂电池应避免在低温下运行。In this study, the samples were soft packaged lithium iron phosphate cells, for the remaining capacity close to 80%. The safety performance of the low temperature-10 was studied. Compared ℃the thermal runaway test results of the cells after the low temperature and room temperature cycling. The content of lithium and the thermal stability of the battery materials were analyzed. It showed that the capacity of cells cycled at the low temperature decreased rapidly. Differential thermal analysis and elemental analysis of electrode cell materials further showed that lithium metal appeared on the anode after low temperature cycling and the thermal stability of battery materials also changed. After an aging with full charge, all the cells after low temperature cycling produced gases, mainly CO and H2. Compared with the fresh cells, the used cells with 80% remaining capacity shows obviously lower electrochemical and thermal safety performances. So the used soft package lithium iron phosphate cells should be avoided to run at low temperatures.

关 键 词：锂离子电池 低温性能 锂枝晶 热安全性能 

分 类 号：O646[理学—物理化学]