Cathode material and preparation method thereof, composite cathode material, and battery
The present disclosure provides a cathode material including multiple composite secondary particles, each of the composite secondary particles including multiple primary cathode material particles, where the composite secondary particles meet: 0.9≤0.1D/A+B*C≤20 (Relation 1). In which A represents a particle size D50 of the primary cathode material particles, unit: μm; B represents a particle size D50 of the composite secondary particles, unit: μm; C represents a specific surface area of the composite secondary particles, unit: m 2 /g; and D represents a number of the primary cathode material particles in each of composite secondary particles.
1 . A cathode material, comprising: a plurality of composite secondary particles, each of the composite secondary particles comprising a plurality of primary cathode material particles, wherein the composite secondary particles meet Relation 1:
0.9≤0.1 D/A+B*C≤ 20 (Relation 1)
where A represents a particle size D50 of the primary cathode material particles, unit: μm; B represents a particle size D50 of the composite secondary particles, unit: μm; C represents a specific surface area of the composite secondary particles, unit: m 2 /g; and D represents a number of the primary cathode material particles in each of the composite secondary particles,
wherein A is in the range of: 0.5≤A≤3.5, B is in the range of: 3≤B≤12, C is in the range of: 0.5≤C≤1.0, and D is in the range of: 1≤D≤50.
2 . The cathode material according to claim 1 , wherein: the primary cathode material particle is LiNi x Co y M z , in which x is in the range of: 0.335≤x≤0.98, y is in the range of: 0.01≤y≤0.33, z is in the range of: 0.01≤z≤0.33, and x+y+z=1; and M is at least one of Mn, Al, Zr, Ti, Y, Sr, or W.
3 . The cathode material according to claim 2 , wherein: the primary cathode material particle is LiNi x Co y M z , in which x is in the range of: 0.33≤x≤0.98, y is in the range of: 0.01≤y≤0.33, z is in the range of: 0.01≤z≤0.33, and x+y+z=1; and M is at least one of Mn, Al, Zr, Ti, Y, Sr, or W.
4 . A composite cathode material, comprising: a cathode material according to claim 1 and a coating on a surface of the cathode material.
5 . The composite cathode material according to claim 4 , wherein a weight proportion of the coating in the composite cathode material is 300-900 ppm.
6 . A battery, comprising: a cathode plate, comprising a current collector and a cathode active material layer is disposed on the current collector, wherein the cathode active material layer comprises a composite cathode material according to claim 4 .