US 12,334,512 B2
Secondary battery and method for manufacturing secondary battery
Yuma Kamiyama, Osaka (JP); Daisuke Nishide, Kobe (JP); and Yukihiro Mizonobe, Himeji (JP)
Assigned to PRIME PLANET ENERGY & SOLUTIONS, INC., Tokyo (JP)
Filed by Prime Planet Energy & Solutions, Inc., Tokyo (JP)
Filed on Feb. 17, 2022, as Appl. No. 17/673,799.
Claims priority of application No. 2021-025171 (JP), filed on Feb. 19, 2021.
Prior Publication US 2022/0271347 A1, Aug. 25, 2022
Int. Cl. H01M 10/0587 (2010.01); H01M 10/04 (2006.01); H01M 10/058 (2010.01); H01M 50/471 (2021.01); H01M 50/474 (2021.01)
CPC H01M 10/0587 (2013.01) [H01M 10/0431 (2013.01); H01M 10/058 (2013.01); H01M 50/471 (2021.01); H01M 50/474 (2021.01)] 10 Claims
OG exemplary drawing
 
1. A secondary battery, comprising:
a flat wound electrode body in which a positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween; and
a battery case that houses the flat wound electrode body, wherein
the flat wound electrode body includes
a pair of curved portions, each of the pair of curved portions having a curved outer surface, and
a flat portion having a flat outer surface connecting the pair of curved portions,
one end portion of the positive electrode plate in a longitudinal direction of the flat wound electrode body is disposed as a positive electrode starting end portion on an inner side of the flat wound electrode body, and the other end portion of the positive electrode plate is disposed as a positive electrode terminating end portion on an outer side of the flat wound electrode body,
one end portion of the negative electrode plate in the longitudinal direction is disposed as a negative electrode starting end portion on the inner side of the flat wound electrode body, and the other end portion of the negative electrode plate is disposed as a negative electrode terminating end portion on the outer side of the flat wound electrode body,
the positive electrode starting end portion is disposed inside the flat portion,
the negative electrode starting end portion extends to come closer to one of the pair of curved portions than the positive electrode starting end portion,
an insufficiently stacked region in which a total number of layers of the positive electrode plate and the negative electrode plate in a thickness direction of the flat wound electrode body is smaller than in other regions in the flat portion is formed in a vicinity of the positive electrode starting end portion in the flat portion,
a protruding portion protruding toward at least a part of the insufficiently stacked region is formed on an inner surface of the battery case, and
the protruding portion extends along a winding axis of the flat wound electrode body.