US 12,308,432 B1
Power-type high-rate lithium iron phosphate cathode material and its preparation method and lithium battery
Ping Lian, Xiangtan (CN); Xinqiao Tan, Xiangtan (CN); Tao Chen, Xiangtan (CN); Zeyu Cao, Xiangtan (CN); Shuai Liu, Xiangtan (CN); and Jia Tang, Xiangtan (CN)
Assigned to Hunan Yuneng new energy battery materials Co., LTD., Hunan (CN)
Filed by Hunan Yuneng new energy battery materials Co., LTD., Xiangtan (CN)
Filed on Jan. 9, 2025, as Appl. No. 19/015,442.
Claims priority of application No. 202410825736.6 (CN), filed on Jun. 25, 2024.
Int. Cl. H01M 4/58 (2010.01); C01B 25/45 (2006.01); H01M 4/36 (2006.01); H01M 4/62 (2006.01); H01M 10/052 (2010.01); H01M 10/42 (2006.01)
CPC H01M 4/5825 (2013.01) [C01B 25/45 (2013.01); H01M 4/366 (2013.01); H01M 4/625 (2013.01); H01M 4/628 (2013.01); H01M 10/052 (2013.01); H01M 10/4235 (2013.01); C01P 2002/50 (2013.01); C01P 2004/03 (2013.01); C01P 2004/62 (2013.01); C01P 2004/80 (2013.01); C01P 2006/40 (2013.01)] 9 Claims
 
1. A preparation method for power-type high-rate lithium iron phosphate cathode material, characterized by comprising the following steps:
(1) adding iron phosphate, lithium source, and organic carbon source into deionized water, stirring evenly, and grinding to nanoscale to obtain a first mixed slurry;
(2) performing drying treatment on the first mixed slurry obtained in step (1) to obtain a first stage precursor powder;
(3) placing the first stage precursor powder obtained in step (2) in a protective atmosphere for calcination treatment to obtain a first stage calcined material; the processing temperature for calcination in step (3) is 400° C.˜1000° C., and the processing time is 3 h˜15 h;
(4) adding the calcined material obtained in step (3) with an organic carbon source, functionalized graphene, and a nitrogen source into deionized water, stirring evenly, and grinding to nanoscale to obtain a second mixed slurry; the functionalized graphene is grafted with a plurality of oxygen-containing functional groups grafted on the surface, showing electronegativity;
(5) performing drying treatment on the second mixed slurry obtained in step (4) to obtain a second stage precursor powder;
(6) placing the second stage precursor powder obtained in step (5) in a protective atmosphere for secondary calcination and crushing to obtain power-type high-rate lithium iron phosphate cathode material.