| 摘要 |
Provided is a lithium secondary battery that consumes an overdischarge current uniformly due to a fine short circuit caused by an electroconductive polymer at a certain overdischarge voltage, and thus has good overdischarge safety. The lithium secondary battery comprises a positive electrode, a negative electrode, a separator for separating the two electrodes from each other, and a non-aqueous electrolytic solution. The separator is formed of a porous film containing electroconductive polymer or having at least one surface coated with electroconductive polymer. The electroconductive polymer is a polythiophene compound represented by the following formula 1. In the formula, R is selected from C1-20 alkyl groups, halo(C1-20) alkyl groups, C2-20 alkenyl groups, C2-20 alkynyl groups, C3-12 cycloalkyl groups, aryl groups, aryl(C1-20) alkyl groups, and halogen atoms, and n is an integer of 2-100,000. |
