US 12,412,921 B2
Positive electrode active material and preparation method thereof, positive electrode plate, lithium-ion secondary battery, and apparatus containing such lithium-ion secondary battery
Shushi Dou, Ningde (CN); Chunhua Hu, Ningde (CN); Yao Jiang, Ningde (CN); Qi Wu, Ningde (CN); Jinhua He, Ningde (CN); and Bin Deng, Ningde (CN)
Assigned to CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED, Hong Kong (CN)
Filed by CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED, Hong Kong (CN)
Filed on Feb. 28, 2022, as Appl. No. 17/682,258.
Application 17/682,258 is a continuation of application No. PCT/CN2020/112914, filed on Sep. 1, 2020.
Claims priority of application No. 201910825311.4 (CN), filed on Sep. 2, 2019.
Prior Publication US 2022/0181675 A1, Jun. 9, 2022
Int. Cl. H01M 4/36 (2006.01); C01G 53/44 (2025.01); H01M 4/52 (2010.01); H01M 4/525 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 10/0525 (2013.01) [C01G 53/44 (2013.01); H01M 4/366 (2013.01); H01M 4/525 (2013.01); C01P 2002/52 (2013.01); C01P 2006/10 (2013.01); C01P 2006/11 (2013.01); C01P 2006/12 (2013.01); C01P 2006/40 (2013.01); H01M 2004/028 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A positive electrode active material, comprising bulk particles and a coating layer applied on an exterior surface of each of the bulk particles, wherein the bulk particles comprises a lithium composite oxide that contains element nickel and a doping element M1, and the coating layer comprises an oxide of element M2;
when the positive electrode active material is in an 11% delithiated state, an average valence of element M1 is α1, and an average valence of element M2 is β1;
when the positive electrode active material is in a 78% delithiated state, an average valence of element M1 is α2, and an average valence of element M2 is β2;
α1 and α2 satisfy α2>α1, and β1 and β2 satisfy β1=β2; and
element M1 comprises one or more of Si, Ti, Cr, Mo, V, Se, Nb, Ru, Rh, Pd, Sb, Te, Ce, and W, and element M2 is selected from one or more of Mg, Al, Ca, Zr, Zn, Y, and B;
wherein a thickness T of the coating layer ranges from 0.001 μm to 0.5 μm, and
the thickness T of the coating layer and an average particle size D of the positive electrode active material satisfy: 0.003≤T/D≤0.025.