US 11,721,804 B2
Carbon-coated lithium iron phosphate positive active material, method for preparing same, positive electrode plate containing same, and lithium-ion battery
Hongyu Liu, Ningde (CN); Changfeng Bie, Ningde (CN); Xue Leng, Ningde (CN); and Na Liu, Ningde (CN)
Assigned to CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED, Ningde (CN)
Filed by CONTEMPORARY AMPEREX TECHNOLOGY CO., LIMITED, Ningde (CN)
Filed on Sep. 6, 2022, as Appl. No. 17/938,930.
Application 17/938,930 is a continuation of application No. PCT/CN2021/114071, filed on Aug. 23, 2021.
Prior Publication US 2023/0062063 A1, Mar. 2, 2023
Int. Cl. H01M 4/36 (2006.01); H01M 4/587 (2010.01); H01M 4/133 (2010.01); H01M 4/136 (2010.01); H01M 10/0525 (2010.01); C01B 25/45 (2006.01); H01M 4/58 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/366 (2013.01) [C01B 25/45 (2013.01); H01M 4/133 (2013.01); H01M 4/136 (2013.01); H01M 4/587 (2013.01); H01M 4/5825 (2013.01); H01M 10/0525 (2013.01); C01P 2002/54 (2013.01); C01P 2004/04 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2004/80 (2013.01); C01P 2006/11 (2013.01); C01P 2006/12 (2013.01); C01P 2006/40 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01); H01M 2220/20 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A carbon-coated lithium iron phosphate positive active material, comprising:
a lithium iron phosphate substrate and a carbon coating layer on a surface of the substrate, the lithium iron phosphate substrate having a general structural formula LiFe1-aMaPO4, wherein M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0≤a≤0.01;
wherein a carbon coating factor of the carbon-coated lithium iron phosphate material is

OG Complex Work Unit Math
wherein BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate, and η satisfies 0.81≤η≤0.95.