METHOD FOR PREPARING SURFACE-MODIFIED LITHIUM/SODIUM MULTICOMPONENT CATHODE MATERIALS

A method for preparing a surface-modified lithium/sodium multi-element cathode material, including lithium-ion battery layered oxides (LiTMO, TM=Ni/Co/Mn) and sodium-ion layered oxides (NaTMO, TM=transition/alkali/alkaline earth metals such as Ti/V/Cr/Mn/Fe/Co/Ni/Cu/Zn/Sn/Ir/Ru/Li/Mg). Taking a high-nickel ternary material (with surface-attached lithium carbonate) as an example: the material is mixed with aluminum diethylphosphinate and sintered in a sintering atmosphere at 500-900° C. for 2-20 h (heating rate: 0.5-5° C./min) to form a coating layer of aluminum phosphate/lithium phosphate. This coating stabilizes the interface, alleviates cyclic crystal structure degradation, and extends cycle life. For sodium-ion layered oxides (NaTMO), a similar modification forms NaAlPOas the surface layer, thereby enhancing electrochemical performance.