US 12,451,485 B2
Pressure-resistant positive active material and electrochemical energy storage apparatus
Rui Du, Ningde (CN); Yongchao Liu, Ningde (CN); Deyu Zhao, Ningde (CN); Sihui Wang, Ningde (CN); Chongheng Shen, Ningde (CN); and Na Liu, Ningde (CN)
Assigned to CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED, Hong Kong (CN)
Appl. No. 17/416,122
Filed by CONTEMPORARY AMPEREX TECHNOLOGY (HONG KONG) LIMITED, Hong Kong (CN)
PCT Filed Nov. 25, 2019, PCT No. PCT/CN2019/120511
§ 371(c)(1), (2) Date Jun. 18, 2021,
PCT Pub. No. WO2020/134774, PCT Pub. Date Jul. 2, 2020.
Prior Publication US 2022/0045324 A1, Feb. 10, 2022
Int. Cl. H01M 4/131 (2010.01); H01M 4/36 (2006.01); H01M 4/525 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [H01M 4/131 (2013.01); H01M 4/366 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A positive active material, wherein the positive active material comprises secondary particles composed of primary particles, the secondary particles have Dv10 of 2 μm to 8 μm, Dv50 of 5 μm to 18 μm, and Dv90 of 10 μm to 30 μm, the primary particles are rod-shaped, cone-shaped, or needle-shaped and have an average length of 200 nm to 1000 nm and an average radial cross-sectional width of 150 nm to 400 nm, an average quantity σ of primary particles per unit sphere surface area in a SEM profile of the secondary particles is 5/μm2 to 30/μm2, and a single-particle pressure-resistant strength of the secondary particles is 150 MPa to 300 MPa; and
a molecular formula of the positive active material is LixNiyCOzMkMepOrAm, wherein 0.95≤x≤1.05, 0≤y≤1, 0≤z≤1, 0≤k≤1, 0≤p≤0.1, 1≤r≤2, 0≤m≤2, and m+r≤2, M is selected from Mn and/or Al, Me is selected from any one or a combination of Zr, Zn, Cu, Cr, Mg, Fe, V, Ti, Sr, Sb, Y, W, and Nb, and A is selected from any one or a combination of N, F, S, and Cl, wherein an outer coating layer is provided on a surface of the positive active material, and an inner coating layer is provided on the surface of at least a portion of the primary particles at non-outermost positions of the secondary particles,
wherein the inner coating layer comprises a coating element selected from any one or a combination of Ba, Zn, W, Y, and P, and the inner coating layer is 0.01% to 0.5% by weight of the positive active material,
wherein the outer coating layer is a composite form of a continuous first coating layer and a discontinuous second coating layer, wherein the continuous first coating layer comprises an oxide of a coating element selected from any one or a combination of W, Y, Si, B, P and Sn, and wherein the discontinuous second coating layer comprises an oxide of a coating element selected from any one or a combination of Zn, and Co, and the outer coating layer is 0.01% to 0.5% by weight of the positive active material;
wherein a powder compacted density of the positive active material is not less than 3.3 g/cm3.