公开(公告)号：US20240405209A1

公开(公告)日：2024-12-05

申请号：US18804688

申请日：2024-08-14

Applicant: BYD COMPANY LIMITED

Inventor： Jiamin LIU ,  Sanzhi CHEN ,  Mengyi DU ,  Rong HAO

IPC: H01M4/36 ,  H01M4/02 ,  H01M4/04 ,  H01M4/136 ,  H01M4/58 ,  H01M10/0525

Abstract: A positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer arranged on at least a surface of the positive electrode current collector. The positive electrode active material layer includes a positive electrode active material, which includes a first lithium iron phosphate material and a second lithium iron phosphate material. When the cumulative volume distribution percentage of the first lithium iron phosphate material is 50%, the particle size is D1v50 μm. When the cumulative volume distribution percentage of the second lithium iron phosphate material is 50%, the particle size is D2v50 μm. D1v50 is 0.3-0.95, and D2v50 is 1.0-3.5. When the volume density of the positive electrode active material reaches a maximum value, the particle size is Dmo μm, the compaction density of the positive electrode sheet is PD g/cm3 under a pressure of 1.5 Mpa, and 0.45≤PD×Dmo≤12.38.

公开(公告)号：US20240128452A1

公开(公告)日：2024-04-18

申请号：US18399192

申请日：2023-12-28

Applicant: BYD COMPANY LIMITED

Inventor： Mengyi DU ,  Sanzhi CHEN ,  Rong HAO

IPC: H01M4/58 ,  C01B25/45 ,  H01M4/131

CPC classification number: H01M4/5825 ,  C01B25/45 ,  H01M4/131 ,  C01P2004/03 ,  C01P2006/10

Abstract: A method for preparing a lithium iron phosphate positive electrode material includes: sequentially grinding, spray-drying and sintering a first mixture slurry containing iron phosphate, a lithium source, a carbon source and a solvent to obtain a spherical first lithium iron phosphate material; sequentially grinding, spray-drying, sintering and crushing a second mixture slurry containing iron phosphate, a lithium source, a carbon source and a solvent to obtain a second lithium iron phosphate material with an irregular morphology; and mixing the first and second lithium iron phosphate materials in equal mass ratio to obtain a lithium iron phosphate positive electrode material, the fitted value of the maximum compaction density of which is C, where C=0.0847t1+0.0196T1−0.0095t2+0.0261T2−33.6716. T1 and t1 represent the sintering temperature and sintering time of the first lithium iron phosphate material respectively, T2 and t2 represent the sintering temperature and sintering time of the second lithium iron phosphate material respectively.