US 11,916,243 B2
Cell case of secondary battery and battery module
Takehiro Takahashi, Tokyo (JP); and Akinobu Kobayashi, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 18/020,407
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Sep. 7, 2021, PCT No. PCT/JP2021/032898
§ 371(c)(1), (2) Date Feb. 8, 2023,
PCT Pub. No. WO2022/080042, PCT Pub. Date Apr. 21, 2022.
Claims priority of application No. 2020-174868 (JP), filed on Oct. 16, 2020.
Prior Publication US 2023/0231250 A1, Jul. 20, 2023
Int. Cl. H01M 10/613 (2014.01); H01M 50/103 (2021.01); H01M 50/15 (2021.01); H01M 50/202 (2021.01); H01M 50/204 (2021.01)
CPC H01M 50/204 (2021.01) [H01M 10/613 (2015.04); H01M 50/103 (2021.01); H01M 50/15 (2021.01); H01M 50/202 (2021.01)] 18 Claims
OG exemplary drawing
 
1. A cell case of a secondary battery comprising:
a rectangular tube-shaped can body,
a can bottom double seamed to a bottom end of the can body, and
a can lid double seamed to a top end of the can body, in which cell case of a secondary battery,
wherein the can bottom has a relief shape, where the relief shape includes a convex shape comprising a can bottom convex part with a center part of the can bottom facing downward and a concave shape comprising a recess with a region between an outer circumference part of the can bottom and the convex shape part further approaching the can lid than the double seam of the can bottom,
wherein a part of the can bottom convex part includes a portion 1 between:
a plane vertical to the can body a distance of 0.5 mm above a bottom end of a double seam of the can body and the can bottom, and
a plane vertical to the can body a distance of 1.0 mm below the bottom end of the double seam of the can body and the can bottom, in a cross-sectional view of the can body and the double seam of the can body and the can bottom, and
wherein an area ratio S1 of the portion 1 with respect to a cross-sectional area of the can body at the bottom end of the double seam of the can body and the can bottom is 50% or more and 90% or less.