Patent ID: 9577238
Date: 2017-02-21
CPC Classifications: H01M,Y02P

Claim:
1. A flat-shaped battery comprising: a power generation element including a positive electrode, a negative electrode, a separator, and an electrolyte; a cylindrical case formed of a conductor and housing the power generation element, the case having a circular bottom and a circular opening; a sealing plate formed of a conductor and closing the opening; an insulating member interposed between the case and the sealing plate; and a plate-shaped current collector disposed between the case and the positive electrode, the current collector being welded to the case and in contact with the positive electrode, wherein a welding point where the current collector is welded to the bottom is set so as to allow contact between the positive electrode and a center portion of the current collector to be maintained when the case is deformed such that a center portion of the bottom is displaced outward of the case, the center portion of the bottom corresponds to a region where a distance from an axial center of the bottom is 0% or more and less than 45% of a radius of the bottom, the welding point comprises two or more welding points set in an outside region where the distance from the axial center of the bottom is 45% or more and 100% or less of the radius of the bottom, and a welding mark at a welded portion between the current collector and the bottom extends from an inner surface to an outer surface of the bottom so as to be inclined with respect to a thickness direction of the bottom toward radially outside of the bottom.