Electrochemical device with alternative separator system

摘要

Provided is an electrochemical device comprising multi-stacked unit cells of full cells or bicells and a separation film disposed therebetween, whereby the separation film and separators are alternately stacked between electrode layers with an opposite polarity. Herein, as the separation film is formed of a material having a higher thermal shrinkage rate than that of the separator, the thermal stability of the device can be secured by stable induction of shutdown via thermal behavior of the separation film, without causing short-circuiting due to thermal shrinkage of the separator even when a temperature of a battery suddenly rises by internal or external factors.