Patent ID: 8138747
Filing Date: 2012-03-20
Classification: H01M,Y02E,Y02P

Abstract:
1. An internal short circuit evaluation method for a battery, the battery comprising an electrode group which is a stacked body including a positive electrode plate, a negative electrode plate wound with a separator interposed between said positive electrode plate and said negative electrode plate, said method comprising steps of: (I) preparing said electrode group to be in a charged state; (II) performing cutting or abrasion on a part of said electrode group while suppressing a short circuit, starting from an outer surface of said electrode group until a predetermined region in said electrode group becomes exposed; (III) pushing or piercing into said predetermined region a pressurizing member with a sharp tip, to cause a short circuit between a portion of said positive electrode plate and a portion of said negative electrode plate which are positioned more inward than said predetermined region; (IV) measuring battery information that changed before and after said short circuit; and (V) detecting a change of said measured battery information, and determining occurrence of an internal short circuit by comparing said measured battery information with a predetermined reference value.