Separator for electrochemical element

摘要

The present invention discloses a separator for an electrochemical element which comprises wet nonwoven fabric containing fibrillated cellulose, non-fibrillated fiber, and fibrillated heat-resistant fiber having all of a softening point, a melting point and a thermal decomposition temperature of 250° C. or higher and 700° C. or lower, and dimensional change rates of MD and CD subjected the wet nonwoven fabric to heat treatment at 250° C. for 50 hours of each −3% to +1%.