改善锂硫电池易燃特性的功能性隔膜研究进展

A review of functional separator for improving the flammability of lithium-sulfur batteries

锂硫电池具有较高的能量密度,可在单兵电源、无人机和乘用车领域应用.锂硫电池以金属锂作为负极,使用时存在安全隐患.由于锂金属表面的不均匀性,循环过程容易生成锂枝晶,使电池内部发生短路,起火燃烧.锂硫电池的能量密度约为普通电池的3～5倍,在充放电过程中发热严重,电池本身过热容易引发电池热失控,造成起火甚至爆炸.使用功能性隔膜可以抑制电池内部短路和热失控的发生,提升锂硫电池的安全性能,可一定程度上削弱循环过程中的飞梭效应.本文综述了锂硫电池功能性隔膜改性工作的最新进展和未来的发展趋势.

Lithium–sulfur(Li–S)batteries have attracted more and more attention lately because they have very high theoretical specific energy(2 500 W?h/kg),five times higher than that of the commercialbatteries.As a result,they are strong contenders for next-generation energy storage in the areas of portable electronics,electric vehicles,and storage systems for renewable energy such as wind power and solar energy.However,poor cycling life,low capacity retention and poor safety are main factors limiting their commercialization.The non-uniform surface of lithium metal tends to form the dendrites during the cycle,causing a short circuit inside and making the battery ignite and burn.Besides,the energy density of lithium-sulfur batteries is about 3～5 times higher.The internal overheating of the battery causes thermal runaway,which can cause fire and explosion.Nevertheless,the use of a functional separator can curb the occurrence of internal short-circuit and thermal runaway of the battery,and improve the safety performance of the lithium-sulfur battery.Meanwhile,the shuttle effect in the cycle can also be weakened to some extent.This article reviews the latest developments and future trends in the functional modification of separators for functional lithium-sulfur batteries.