In nature, lithium is the lightest metal with the smallest atomic mass. Lithium is chemically active, and it is easy to lose electrons to be oxidized to Li+. The standard electrode potential is -3.045V, and the electrochemical equivalent is 0.26g/Ah. These characteristics determine that it is a material with a very high specific energy. The ternary lithium battery refers to a lithium secondary battery using three kinds of transition metal oxides of nickel, cobalt and manganese as a positive electrode material. It fully integrates the good cycle performance of lithium cobaltate, the high specific capacity of lithium nickelate and the high safety and low cost of lithium manganate. It synthesizes nickel by molecular level mixing, doping, coating and surface modification. A multi-element synergistic composite lithium intercalation oxide such as cobalt manganese is a lithium ion rechargeable battery that has been widely studied and applied.