US 12,266,785 B2
Secondary battery
Kazuhiro Yoshii, Osaka (JP); and Takahiro Takahashi, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Appl. No. 17/441,491
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
PCT Filed Jan. 27, 2020, PCT No. PCT/JP2020/002662
§ 371(c)(1), (2) Date Sep. 28, 2021,
PCT Pub. No. WO2020/195091, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 2019-058805 (JP), filed on Mar. 26, 2019.
Prior Publication US 2022/0181606 A1, Jun. 9, 2022
Int. Cl. H01M 4/36 (2006.01); H01M 4/02 (2006.01); H01M 4/13 (2010.01); H01M 4/131 (2010.01); H01M 4/139 (2010.01); H01M 4/1391 (2010.01); H01M 4/48 (2010.01); H01M 4/62 (2006.01); H01M 10/0525 (2010.01)
CPC H01M 4/364 (2013.01) [H01M 4/13 (2013.01); H01M 4/139 (2013.01); H01M 4/483 (2013.01); H01M 4/62 (2013.01); H01M 10/0525 (2013.01); H01M 2004/028 (2013.01); H01M 4/131 (2013.01); H01M 4/1391 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A secondary battery, comprising:
a positive electrode having a positive electrode core and
a positive electrode mixture layer provided on a surface of the positive electrode core, wherein:
the positive electrode mixture layer includes a positive electrode active material composed of secondary particles formed by aggregating primary particles;
a packing density of the positive electrode active material in the positive electrode mixture layer is 3.2 g/cm3 or higher; and
a crushing rate of 30 particles of the positive electrode active material being present on a surface of the positive electrode mixture layer is 75% or lower,
wherein a surface layer including an inorganic compound and a binder is provided on a surface of the positive electrode mixture layer, wherein the surface layer is porous, and
a basis weight of the inorganic compound is 3 to 13 g/m2,
wherein a crushing rate of 30 particles of the positive electrode active material being present apart from the surface of the positive electrode mixture layer is lower than a crushing rate determined with 30 particles of the positive electrode active material being present on the surface of the positive electrode mixture layer.