A sealed battery includes a battery can with a bottomed cylindrical shape having an opening, an electrode body accommodated in the battery can, and a sealing plate closing the opening of the battery can. The sealing plate has a first main surface facing an outside of the battery can and a second main surface opposite to the first main surface. The first main surface has a first groove therein with an arc shape. The second main surface has a second groove therein with an arc shape disposed to correspond to the first groove. The first groove has a central angle A1 smaller than a central angle A2 of the second groove. The first groove intersects a symmetry axis of the second groove on the second groove when viewed in a normal direction of the first main surface.
1 . A sealed battery comprising:
a battery can with a bottomed cylindrical shape having an opening;
an electrode body accommodated in the battery can; and
a sealing plate closing the opening of the battery can, wherein
the sealing plate has a first main surface facing an outside of the battery can and a second main surface opposite to the first main surface and facing an inside of the battery can,
the first main surface has a first groove therein, the first groove having an arc shape,
the second main surface has a second groove therein, the second groove having an arc shape,
the first groove has a central angle A1 smaller than a central angle A2 of the second groove,
the first groove is symmetrical about a first symmetry axis, and the second groove is symmetrical about a second symmetry axis,
the first groove intersects the second symmetry axis of the second groove when viewed in a normal direction of the first main surface,
at least a part of the first groove overlaps the second groove when viewed in the normal direction of the first main surface, and
the central angle A1 of the first groove is more than or equal to 60° and less than or equal to 220°.
2 . The sealed battery according to claim 1 , wherein the central angle A2 of the second groove is more than or equal to 180° and less than or equal to 300°.
3 . The sealed battery according to claim 1 , wherein an acute angle AC formed by the first symmetry axis of the first groove and the second symmetry axis of the second groove is less than or equal to 60° when viewed in the normal direction of the first main surface.
4 . The sealed battery according to claim 1 , wherein the first symmetry axis of the first groove agrees with the second symmetry axis of the second groove when viewed in the normal direction of the first main surface.
5 . The sealed battery according to claim 1 , wherein the central angle A1 is defined by a pair of circumferential ends of the arc shape of the first groove, and each of said pair of circumferential ends is immediately adjacent to the first main surface.
6 . The sealed battery according to claim 1 , wherein the sealing plate has a thin part thereof defined between respective bottom surfaces of the first groove and the second groove.
7 . The sealed battery according to claim 1 , wherein the sealing plate includes a monolithic plate defining the first main surface and the second main surface.
8 . The sealed battery according to claim 1 , wherein an acute angle formed by the first symmetry axis of the first groove and the second symmetry axis of the second groove is more than 0° when viewed in the normal direction of the first main surface.
9 . A sealed battery comprising:
a battery can with a bottomed cylindrical shape having an opening;
an electrode body accommodated in the battery can; and
a sealing plate closing the opening of the battery can, wherein
the sealing plate has a first main surface facing an outside of the battery can and a second main surface opposite to the first main surface and facing an inside of the battery can,
the first main surface has a first groove therein, the first groove having an arc shape,
the second main surface has a second groove therein, the second groove having an arc shape,
the first groove has a central angle A1 smaller than a central angle A2 of the second groove,
the first groove is symmetrical about a first symmetry axis, and the second groove is symmetrical about a second symmetry axis,
the first groove intersects the second symmetry axis of the second groove when viewed in a normal direction of the first main surface,
at least a part of the first groove overlaps the second groove when viewed in the normal direction of the first main surface, and
the central angle A2 of the second groove is more than or equal to 180° and less than or equal to 300°.
10 . The sealed battery according to claim 9 , wherein an acute angle AC formed by the first symmetry axis of the first groove and the second symmetry axis of the second groove is less than or equal to 60° when viewed in the normal direction of the first main surface.
11 . The sealed battery according to claim 9 , wherein the first symmetry axis of the first groove agrees with the second symmetry axis of the second groove when viewed in the normal direction of the first main surface.
12 . The sealed battery according to claim 9 , wherein the central angle A1 is defined by a pair of circumferential ends of the arc shape of the first groove, and each of said pair of circumferential ends is immediately adjacent to the first main surface.
13 . The sealed battery according to claim 9 , wherein the sealing plate has a thin part thereof defined between respective bottom surfaces of the first groove and the second groove.
14 . The sealed battery according to claim 9 , wherein the sealing plate includes a monolithic plate defining the first main surface and the second main surface.
15 . The sealed battery according to claim 9 , wherein an acute angle formed by the first symmetry axis of the first groove and the second symmetry axis of the second groove is more than 0° when viewed in the normal direction of the first main surface.