METHOD FOR MANUFACTURING ELECTRICAL STORAGE DEVICE
The manufacture method disclosed herein is a method for manufacturing an electrical storage device, including a step of preparing an outer case in which a peripheral part of an opening is a flat surface, and a lid assembly obtained by integral molding of a lid, a terminal member and an insulating member, a step of attaching the lid assembly to the opening of the outer case, and a step of irradiating the boundary of the peripheral part and an outer edge part with laser light. The lid assembly is placed so that an inclined part will become thinner from the outer surface toward the boundary with the outer case, and the outer surface of the lid is placed at a higher place than the peripheral part of the opening, and the inner surface of the lid is placed at a lower place than the peripheral part of the opening.
1 . A method for manufacturing an electrical storage device, comprising,
a case, comprising an outer case having an opening on one side surface and a bottom, and a lid having terminal attachment holes and sealing the opening,
an electrode body accommodated in the case,
a terminal member, having an one end electrically connected to the electrode body in an inside of the case, and the other end exposed to an outside of the lid, and
a resin insulating member, which insulates a surface of the lid, which is an outer surface on an outside of the case, the opening of which is sealed, from the terminal member,
the method comprising,
a step of preparing the outer case in which a peripheral part of the opening is a flat surface, and a lid assembly, wherein the lid assembly is obtained by integral molding of the lid, the terminal member and the insulating member;
a step of attaching the lid assembly to the opening of the outer case; and
a step of laser welding of the outer case and the lid assembly by irradiating a boundary between the peripheral part of the opening and an outer edge part of the lid with laser light from an outer surface side of the lid;
wherein the lid prepared in the preparation step has an inclined part, which becomes thinner from a middle side toward the outer edge part of the lid, in a region in which the outer edge part of the lid and the insulating member are closest to each other,
the lid assembly is placed so that the inclined part will become thinner from the outer surface toward a boundary with the outer case in the attachment step, and
an outer surface of the lid is placed at a higher place than the peripheral part of the opening, and an inner surface of the lid is placed at a lower place than the peripheral part of the opening.
2 . The manufacture method according to claim 1 ,
wherein the outer case prepared in the preparation step has a rectangular opening, a rectangular bottom surface facing the opening, a pair of first side walls extended from the bottom surface and facing each other, and a pair of second side walls extended from the bottom surface and facing each other,
the lid assembly prepared in the preparation step has a rectangular lid, and the inclined part is provided to span a whole circumference of the outer edge part of the lid.
3 . The manufacture method according to claim 1 , wherein when a maximum thickness of the lid is 100%, the lid assembly prepared in the preparation step has the inclined part in a region of 50% or less from the outer surface in a thickness direction.
4 . The manufacture method according to claim 1 , wherein when the maximum thickness of the lid is 100%, the peripheral part of the opening is placed in a region of 25% or more and less than 50% from the inner surface in a thickness direction in the attachment step.