Rechargeable batteries and rechargeable battery modules

Abstract

This invention provides a secondary battery and a secondary battery module with excellent welding strength between the opening of the outer casing and the lid member. [Solution] The secondary battery of the embodiment comprises an outer casing having a bottom wall and side walls and an opening, an electrode group housed in the outer casing, and a lid member fixed to the opening of the outer casing by a weld. The weld has a first connecting portion in a cross section along the direction in which the electrode group is housed, which connects the side wall and the bottom surface of the lid member on the inside of the outer casing. The first connecting portion is concave toward the outside of the outer casing.

Claims

1. An outer container having a bottom wall and side walls, and an opening, The electrode group housed in the aforementioned outer can, The outer can comprises a lid member fixed to the opening by a weld, The welded portion has a first connecting portion in a cross-section along the housing direction of the electrode group that connects the side wall and the bottom surface of the lid member on the inside of the outer can, The first connecting portion is concave toward the outside of the outer casing of the welded portion, in a secondary battery.

2. The aforementioned opening is rectangular in shape, having a long side and a short side. The secondary battery according to claim 1, wherein the first connecting portion of the welded portion is located on at least one of the side walls on the short side of the outer casing.

3. The welded portion has, in a cross-section along the direction of housing the electrode group, a first interface with the side wall of the outer container and a second interface with the lid member. The secondary battery according to claim 1, wherein the angle formed by a first virtual boundary line connecting the outer end and inner end of the outer casing of the first interface and a second virtual boundary line connecting the outer end and inner end of the lid member of the second interface is 90° or less.

4. The welded portion has a second connecting portion in a cross-section along the housing direction of the electrode group that connects the side wall and the upper surface of the lid member on the outside of the outer can, The secondary battery according to claim 1, wherein the second connecting portion is concave toward the inside of the outer casing of the welded portion.

5. In the cross-section of the electrode group of the welded portion along the storage direction, there is a second connecting portion that connects the side wall and the upper surface of the lid member on the outside of the outer can, The secondary battery according to claim 1, wherein the shortest distance between the first connecting portion and the second connecting portion is longer than the thickness of the side wall of the outer casing.

6. The secondary battery according to claim 1, External terminals provided on the aforementioned secondary battery, A secondary battery module comprising a connecting member electrically connected to the external terminals.

Images