US 12,034,162 B2
Method for manufacturing nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery
Atsutoshi Ako, Hyogo (JP); Yoshifumi Magari, Hyogo (JP); Kazuaki Tamura, Hyogo (JP); and Akira Nishida, Hyogo (JP)
Assigned to SANYO Electric Co., Ltd., Osaka (JP)
Appl. No. 17/426,831
Filed by SANYO Electric Co., Ltd., Daito (JP)
PCT Filed Nov. 27, 2019, PCT No. PCT/JP2019/046298
§ 371(c)(1), (2) Date Jul. 29, 2021,
PCT Pub. No. WO2020/162000, PCT Pub. Date Aug. 13, 2020.
Claims priority of application No. 2019-021805 (JP), filed on Feb. 8, 2019.
Prior Publication US 2022/0123296 A1, Apr. 21, 2022
Int. Cl. H01M 4/525 (2010.01); H01M 4/02 (2006.01); H01M 4/505 (2010.01); H01M 10/0525 (2010.01); H01M 10/0587 (2010.01)
CPC H01M 4/525 (2013.01) [H01M 4/505 (2013.01); H01M 10/0525 (2013.01); H01M 10/0587 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method for manufacturing a non-aqueous electrolyte secondary battery, the method including:
a winding body formation step of winding a positive electrode plate, a negative electrode plate, and a separator around an elliptical winding core to form a winding body; and
an electrode assembly formation step of removing the winding core from the winding body and then pressing the winding body to form a flat wound electrode assembly,
wherein
the positive electrode plate includes
a positive core body, and
a positive electrode mixture layer formed on each side of the positive core body,
the positive electrode mixture layer includes a lithium metal composite oxide represented by general formula Li1+xMaO2+b (where x, a, and b satisfy conditions that x+a=1, −0.2<x≤0.2, −0.1≤b≤0.1, and M includes Ni and Co and includes at least one element selected from the group consisting of Mn and Al),
a softness index of the positive electrode plate is 15 to 19, and
a ratio of the longest inner peripheral diameter of the winding body to the longest inner peripheral diameter of the wound electrode assembly is 71% to 94%.