Single-crystal ternary cathode material, preparation method therefor, cathode electrode sheet, and battery

A single-crystal ternary cathode material, having an apparent factor

• Z
• =
• (
• 1
• S
• ⁡
• (
• D
• 9
• ⁢
• 0
• )
• )
• x
• ×
• H
• 1
• .
• 2
• -
• 1
• ⁢
• 9
• .
• 4
• ×
• 0
• .
• 1
• ⁢
• 8
• x
• ,
• with Z=1.1 to 3.0;
• wherein, x=D90/D10, 2≤x≤5;
• D90 is a particle size of the single-crystal ternary cathode material when volume-based cumulative particle size distribution of the single-crystal ternary cathode material reaches 90%, D10 is a particle size of the single-crystal ternary cathode material when the volume-based cumulative particle size distribution of the single-crystal ternary cathode material reaches 10%;
• D10 of the single-crystal ternary cathode material does not exceed 2.4 μm;
• S(D90) is a number-average circularity equal to a sum of circularities of all target particles contained in the single-crystal ternary cathode material divided by n;
• the circularity Q=l2/l1, wherein an area and a perimeter corresponding to a two-dimensional projected image of an individual target particle are defined as S1 and l1 respectively, a perimeter of a circle with the area S1 is defined as l2, the target particle is defined as a single-crystal ternary cathode material particle with a particle size greater than or equal to D90 in the single-crystal ternary cathode material, and n is a total number of the target particles contained in the single-crystal ternary cathode material;
• and
• H is hardness,
• H
• =
• D
• 1
• ⁢
• 0
• ′
• D
• 1
• ⁢
• 0
• ×
• 1
• ⁢
• 0
• ⁢
• 0
• ⁢
• %
• ,
• wherein D10′ is a particle size when volume-based cumulative particle size distribution of a pressed material reaches 10%, the pressed material is a material obtained by pressing the single-crystal ternary cathode material under a pressure of 200 MPa;
• and the D10′ of the single-crystal ternary cathode material does not exceed 2.3 μm.