Hitachi Automotive Systems, Ltd.

Vehicle Energy Japan Inc.

Shou Saimaru

Naoki Kojima

Kazuaki Urano

Takuro Tsunaki

Keisuke Sawada

Yukihiro Soga

A secondary battery includes a diaphragm which is disposed on a current path between a current collector plate connected to a wound electrode group in a battery container and an external terminal, deforms when an internal pressure of the battery container increases, and breaks the current path. The diaphragm has a convex portion which protrudes to the current collector plate. The current collector plate has a through-hole into which the convex portion is inserted. An inner wall portion of the through-hole and a side wall portion of the convex portion facing each other are welded.

Secondary battery

A square secondary battery includes a can housing a power generation element, a lid sealing an opening of the can, an external terminal arranged on the lid, a current collector connected to each of the electrodes of the power generation element, and a connection terminal connecting the current collector and the external terminal by passing through the lid. The external terminal has a flat plate shape arranged along the lid and is made of a clad material in which two flat plate portions made of mutually dissimilar metals are clad-joined on wide-width surfaces and the connection terminal is joined by welding with, of the two flat plate portions of the external terminal, the flat plate portion arranged on a side of the lid.

Rectangular secondary battery

A square battery includes a battery can surrounded by four side wall portions, and having an upper end portion on one side in a height direction of the side wall portions opened and a bottom portion in a lower end portion on the other side in the height direction, and a battery lid welded to the upper end portion to seal the battery can, wherein between the battery can and the battery lid, a lateral boundary surface in a lateral direction crossing the height direction of the side wall portions and a vertical boundary surface in a vertical direction crossing the lateral boundary surface and along the height direction of the side wall portions are formed, at least a part of the lateral and vertical boundary surfaces being welded by a laser radiated in the vertical direction along the height direction of the side wall portions.

Growing community of inventors

Hitachinaka, Japan

Shou Saimaru