PROPYLENE RESIN MICROPOROUS FILM, BATTERY SEPARATOR, BATTERY, AND METHOD FOR PRODUCING PROPYLENE RESIN MICROPOROUS FILM

Provided is a propylene resin microporous film which has excellent lithium ion permeability, and can be used to fabricate a high-performance lithium ion battery and prevent short circuits between positive and negative electrodes by dendrites. The propylene resin microporous film has micropores formed by uniaxially stretching a propylene resin film, a degree of air permeability of 100 to 400 s/100 mL, and a rate of surface aperture of 30 to 55%.