Patent ID: 8920953
Filing Date: 2014-12-30
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
1. A lithium ion secondary battery having a flat shape, the battery comprising: an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator, the electrode assembly being wound around an axis into a flat shape having a curved end defining a corner portion; and an elastic member arranged inside the electrode assembly and into at least the corner portion of the electrode assembly such that at least a portion of the elastic member is positioned between at least a portion of one of the positive electrode plate and the negative electrode plate and at least a portion of the separator in a direction perpendicular to the axis, the elastic member being made of a material having porosity, and wherein the elastic member is made of at least one material selected from the group consisting of polyethylene, polypropylene, and polyurethane.