A polyethylene microsphere-coated separator with rapid thermal shutdown function for lithium-ion batteries

• 来源期刊: 能源化学
• 年，卷（期）: 2020,（5）
• 页码范围: 33-40
• 页数: 8页
• 语种: 英文

摘要

Thermal runaway is the main factor contributing to the unsafe behaviors of lithium-ion batteries (LIBs) in practical applications.The application of separators for the thermal shutdown has been proven as an effective approach to protecting LIBs from thermal runaway.In this work,we developed a thermal shutdown separator by coating a thin layer of low-density polyethylene microspheres (PM) onto a commercial porous polypropylene (PP) membrane and investigated the thermal response behaviors of the as-prepared PM/PP separator in LIBs.The structural and thermal analysis results revealed that the coated PM layer had a porous structure,which facilitated the occurrence of normal charge-discharge reactions at ambient temperature,although it could melt completely and fuse together within very short time periods:3s at 110 ℃ and 1 s at 120℃,to block off the pores of the PP substrate,thereby cutting off the ion transportation between the electrodes and interrupting the battery reaction.Consequently,the PM/PP separator exhibits very similar electrochemical performance to that of a conventional separator at ambient temperature.However,it performs a rapid thermal shutdown at an elevated temperature of ～110℃,thus controlling the temperature rise and maintaining the cell in a safe status.Due to its synthetic simplicity and low cost,this separator shows promise for possible application in building safe LIBs.