摘要
隔膜对锂离子电池的安全性能有重要影响。聚丙烯(PP)、聚乙烯(PE)等商用隔膜的熔点偏低,在高温下会发生熔化,导致大面积内短路,引发电池热失控。将SiO 2/聚乙烯醇(PVA)浆料直接涂覆在电极表面,形成电极支撑型复合隔膜,取代传统的PP/PE隔膜,以提升电池的安全性能。复合隔膜厚度约为30μm,在400℃下不发生收缩形变,制备方法与现有电池生产线匹配较好,可实现锂离子电池的规模化量产。基于负极支撑型复合隔膜的20 Ah软包装电池,以0.5 C的电流在2.50~3.65 V循环500和1000次后,容量保持率分别为95%和88%。在200℃、300℃加热测试中,电池不发生热失控;针刺测试中,电池表面最高温度仅为36℃,且无鼓胀现象。
The separator had an important influence on the safety performance of the Li-ion battery.The melting point of commercial separators such as polypropylene(PP)and polyethylene(PE)was low,which would melt at high temperature,resulting in a large area of internal short circuit and causing thermal runaway of the battery.SiO 2/polyvinyl alcohol(PVA)slurry was directly coated on the surface of the electrode to form an electrode supported composite separator,which replaced traditional PE/PP separator and improved the safety performance of Li-ion battery.The composite separator with the thickness of about 30μm exhibited almost no shrinkage deformation at 400℃.The preparation method matched well with the existing battery production line,which could achieve the large-scale production of Li-ion battery.Based on the anode supported composite separator,the 20 Ah pouch battery displayed a capacity retention rate of 95%and 88%respectively after 500 and 1000 cycles at a current of 0.5 C in 2.50-3.65 V.There was no thermal runaway occurred in the battery after the heating test at 200℃and 300℃.In the nail penetration test,the maximum surface temperature of the battery was only 36℃without swelling.
作者
于冉
金翼
刘家亮
孙召琴
YU Ran;JIN Yi;LIU Jia-liang;SUN Zhao-qin(China Electric Power Research Institute,Beijing 100192,China)
出处
《电池》
CAS
北大核心
2022年第6期661-665,共5页
Battery Bimonthly
基金
国家电网公司资助项目(DG71-20-003)。
关键词
复合隔膜
锂离子电池
规模化量产
安全性能
热失控
composite separator
Li-ion battery
large-scale production
safety performance
thermal runaway
作者简介
通信作者:于冉(1991-),女,山东人,中国电力科学研究院有限公司工程师,博士,研究方向:锂离子电池技术;金翼(1980-),男,安徽人,中国电力科学研究院有限公司储能电池材料技术研究室主任,博士,研究方向:储能技术;刘家亮(1972-),男,湖北人,中国电力科学研究院有限公司储能与电工所总工程师,硕士,研究方向:电池储能技术;孙召琴(1986-),女,山东人,中国电力科学研究院有限公司工程师,硕士,研究方向:新型电化学储能技术。
