Patent attributes
A flat-shaped battery of the present invention includes an outer can that is open upward, a sealing can that is open downward, and a gasket that is placed between the outer can and the sealing can to seal the space between them. The outer can includes a base plate and a cylindrical surrounding wall. The surrounding wall of the outer can includes a straight portion that extends upward and perpendicular to the base plate. The sealing can includes a housing in the form of an inverted dish, a flange that projects outward from a lower end of the opening of the housing, and a single outer surrounding wall that extends downward from an outside edge of the flange so as to be perpendicular to the flange. The outer surrounding wall of the sealing can is arranged perpendicular to the base plate of the outer can. The gasket includes a base that receives a lower end of the outer surrounding wall of the sealing can, and an outer cylindrical wall that extends upward from the base and is disposed between the surrounding wall of the outer can and the outer surrounding wall of the sealing can. The surrounding wall of the outer can has a curved edge such that the surrounding wall at the opening of the outer can is bent toward an axis of the outer can and positioned laterally with respect to the outer surrounding wall of the sealing can. The curved edge presses an upper end of the outer cylindrical wall of the gasket against an upper end of the outer surrounding wall of the sealing can.