COMPOSITION FOR FORMING HEAT-RESISTANT POROUS LAYER, SEPARATION MEMBRANE COMPRISING HEAT-RESISTANT POROUS LAYER AND ELECTROCHEMICAL BATTERY USING SEPARATION MEMBRANE, AND FABRICATION METHOD OF SEPARATION MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide a separation membrane capable of maintaining a shape thereof without being fractured even in an environment where the internal temperature of a battery rises to 200°C or above in several seconds, and an electrochemical battery using the separation membrane.SOLUTION: A heat-resistant porous layer composition for an electrochemical battery separation membrane includes: one selected from among a monomer, oligomer and polymer including an oxyethylene group, or a mixture thereof; one selected from a polyvinylidene fluoride-based homopolymer and a polyvinylidene fluoride-hexafluoropropylene-based copolymer, or a mixture thereof; an initiator; and a solvent. A unit originating from hexafluoropropylene in the polyvinylidene fluoride-hexafluoropropylene-based copolymer is present in an amount of 15 wt.% or less based on the weight of the polyvinylidene fluoride-hexafluoropropylene-based copolymer, and the polyvinylidene fluoride-hexafluoropropylene-based copolymer has a weight average molecular weight of 600,000 or more.SELECTED DRAWING: Figure 1