A high temperature stable ceramic coated separator prepared with polyimide binder/Al2O3 particles for lithium ion batteries
Abstract An effective and practical way to develop the lithium ion power batteries with better safety performance is to increase the thermal shrinkage resistance of the separator at high temperature. In this work, a ceramic coating separator (CCS PI) is manufactured by coating Al 2 O 3 ultrafine powder and thermal stable polyimide binder onto the surface of the porous polyethylene (PE) membrane. CCS PI exhibits no thermal shrinkage up to 160 degC in dry state and maintains stable when packed inner the cells up to 165 degC. Meanwhile CCS PI hasn't been punctured during the hot metal rod piercing testing. The above results all prove that the CCS PI has high thermo stability. In addition, the CCS PI presents higher electrolyte uptake, better wettability with the electrolyte and enabled high ionic conductance when it is saturated with liquid electrolyte. The cells with this CCS PI show good cyclic performance. Therefore, as prepared CCS PI is a promising separator to improve thermal safety and capacity retention for lithium ion power batteries.