The invention discloses a high-capacity
metal lithium powder composite cathode and a preparation method thereof and a multi-layer
composite electrode. The high-capacity
metal lithium powder composite cathode comprises the following components in part by weight: 1 to 80 parts of
metal lithium powder, 10 to 90 parts of
cathode powder, 1 to 10 parts of conductive agent, 1 to 4.5 parts of
adhesive and 0 to 0.5 part of surfactant. By compounding the metal lithium powder with materials such as
graphite, soft carbon, hard carbon,
tin and oxides thereof,
silicon and oxides thereof and the like,
mass ratio capacity and volume ratio capacity of a
cathode material are improved, using amount of active substances is reduced, and the battery specific capacity is improved; the specific capacity of the
cathode can be adjusted by adjusting the rate of metal lithium to the
graphite;
short circuit in a battery caused by piercing of a diaphragm through metal dendritic
crystal growth can be effectively prevented through the separation of an insulating protective layer, so that the safety performance of the battery is improved; and the metal lithium powder is counteracted with irreversible
capacity loss of the cathode, and primary Kulun efficiencies of the
graphite, the hard carbon, the soft carbon, the
tin, the
silicon and other cathode materials are improved.