Electrode active material and preparation method thereof, electrode, battery, and apparatus

A method of making an electrode active material comprising a core and a coating layer, the method comprising:

• providing a core comprising a ternary material selected from the group consisting of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, or a combination thereof;
• providing a solution comprising an organic sulfur-containing compound, the organic sulfur-containing compound;
• applying the solution on at least a surface of the core;
• and
• curing the solution to form the coating layer disposed on the surface of the core,
• wherein the coating layer comprises a reaction product of the organic sulfur-containing compound, and the reaction product comprises Li, S, and O,
• wherein the organic sulfur-containing compound is selected from the group consisting of mercaptan, thiophenol, thioether, thioaldehyde, thioketone, thiocarboxylic acid, sulfoxide, sulfone, sulfur oxoacid, a derivative of sulfur oxoacid, and any combination thereof.