Patent ID: 10217988

Abstract:
Provided is a secondary battery with a high electric characteristic and reliability that prevents the short circuit between a positive electrode and a negative electrode by an insulating member and that prevents or reduces the volume increase and deformation of a battery electrode assembly. A secondary battery includes a battery electrode assembly in which positive electrode 1 and negative electrode 6 are alternately laminated while separator 20 is interposed therebetween. Positive electrode 1 and negative electrode 6 include current collectors 3, 8 and active materials 2, 7, each surface of current collectors 3, 8 is provided with an application portion and a non-application portion of active materials 2, 8, and the active materials 2, 7 include a thin portion whose thickness is small. A charging capacity ratio A/C between negative electrode 6 and positive electrode 1 that face each other at an outer edge portion containing the thin portion is greater than the charging capacity ratio A/C between negative electrode 6 and positive electrode 1 that face each other at a center side with respect to the outer edge portion.