US 12,451,522 B2
Secondary battery, electronic device, and power tool
Akira Shinkawa, Kyoto (JP)
Assigned to Murata Manufacturing Co., Ltd., Kyoto-fu (JP)
Filed by MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed on Aug. 5, 2022, as Appl. No. 17/881,976.
Application 17/881,976 is a continuation of application No. PCT/JP2021/009420, filed on Mar. 10, 2021.
Claims priority of application No. 2020-049176 (JP), filed on Mar. 19, 2020.
Prior Publication US 2022/0393253 A1, Dec. 8, 2022
Int. Cl. H01M 10/0587 (2010.01); H01M 4/66 (2006.01); H01M 50/531 (2021.01); H01M 4/02 (2006.01)
CPC H01M 10/0587 (2013.01) [H01M 4/662 (2013.01); H01M 50/531 (2021.01); H01M 2004/021 (2013.01); H01M 2220/30 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A secondary battery comprising:
an electrode winding body having a structure in which a strip-shaped positive electrode and a strip-shaped negative electrode are stacked with a separator interposed therebetween and wound around a central axis, a positive electrode current collector plate, and a negative electrode current collector plate are housed in a battery can,
the positive electrode having a positive electrode active material covered portion covered with a positive electrode active material layer and a positive electrode active material non-covered portion on a strip-shaped positive electrode foil,
the negative electrode having a negative electrode active material covered portion covered with a negative electrode active material layer and a negative electrode active material non-covered portion on a strip-shaped negative electrode foil,
the positive electrode active material non-covered portion being joined to the positive electrode current collector plate at one end portion of the electrode winding body,
the negative electrode active material non-covered portion being joined to the negative electrode current collector plate at the other end portion of the electrode winding body,
the electrode winding body having a flat surface formed by bending any one or both of the positive electrode active material non-covered portion and the negative electrode active material non-covered portion toward a central axis of the wound structure and overlapping the positive electrode active material non-covered portion and the negative electrode active material non-covered portion, and a groove formed in the flat surface,
a region other than the groove in the flat surface is joined to the positive electrode current collector plate, the negative electrode current collector plate, or both,
the positive electrode current collector plate having a positive electrode bead on a surface thereof, the negative electrode current collector plate having a negative electrode bead on a surface thereof,
a width of the positive electrode bead being 0.05 mm or more and 0.18 mm or less, a width of the negative electrode bead being 0.03 mm or more and 0.12 mm or less,
a thickness of the positive electrode current collector plate being 0.07 mm or more and 0.20 mm or less, a thickness of the negative electrode current collector plate being 0.05 mm or more and 0.15 mm or less,
a thickness of the positive electrode active material non-covered portion being 5 μm or more and 20 μm or less, a thickness of the negative electrode active material non-covered portion being 6 μm or more and 20 μm or less, and
the positive electrode active material non-covered portion includes two or more positive electrode active material non-covered portions overlapping on a positive electrode side, and the negative electrode active material non-covered portion includes two or more negative electrode active material non-covered portions overlapping on a negative electrode side.