Cathode active material and preparation method thereof, positive electrode plate, battery, and electrical apparatus

A cathode active material, wherein an offset angle of a (104) diffraction peak of the cathode active material is αnm, wherein:

• n is the number of charging cycles of a battery comprising the cathode active material, n being an integer;
• m % is a percentage of a charging capacity to a total capacity of the battery at a n-th charging cycle of the battery;
• αnm is a 2θ value corresponding to the (104) diffraction peak in an XRD diffraction spectrum of the cathode active material when the percentage of the charging capacity to the total capacity of the battery is m % at the n-th charging cycle of the battery;
• and
• αnm satisfies:
• α10050−α1000≤0.250°, and α100100−α1000≤1.500°,
• wherein the cathode active material comprises a lithium-containing metal oxide having a chemical formula represented by formula (1):
• LiaNixCoyMnzMbO2 (1),
• where:
• 0.9≤a≤1.2, 0.3≤x<0.99, 0.01≤y≤0.5, 0.01≤z≤0.5, 0≤b>0.2;
• and
• M is selected from at least one of Al, Zr, Y, Ti, Nb, Cr, Er, Mg, Ba, V, Sr, Ta, Mo, W, or Ce,
• wherein the cathode active material further comprises a coating layer disposed on a surface of the lithium-containing metal oxide, the coating layer comprising oxide containing at least one element of Al, B, Si, W, Ti, or Ce.