FabricationofThermallyStableSeparatorsUsingHydroxyl-ContainingCopolyimideforLithium-IonBattery

Abstract

Wesynthesizedhydroxylcopolyimide(HcoPI)viaazeotropicimidizationandfabricatedtwotypesofthethermallystableHcoPI-containingmembranebyelectrospinning(ES-HcoPI),andHcoPInanoparticle-coatedcomposite(S-NP-PE)asalithium-ionbattery(LIB)separator.HcoPInanoparticles(HcoPI-NP)werepreparedbyreprecipitationmethodandfabricatedintoHcoPI-NP-coatedpolyethylene(PE)separatorwithcarboxymethylcellulose(CMC)/styrenebutadienerubber(SBR)usedasabinderforthewater-basedslurry.ForpreparationofHcoPI-NP,severalparameterstoformHcoPInanoparticleswereoptimizedforHcoPI-NPsizeanddistribution.ComparedtocommercialPEseparator,ES-HcoPIandS-NP-PEexhibitedenhancedelectrolyteaffinity,thereforetheyshowedhigherelectrolyteuptakesandionicconductivitiesthanthoseofcommercialPEseparator.Inaddition,ES-HcoPIandS-NP-PEexhibitedexcellentthermalstabilityat150℃.Importantly,thecoincelltestusingES-HcoPIshowedanenhancedelectrochemicalperformanceduetoitsexcellentelectrolyteuptake.