The present invention relates to a preparation method of a
solid state
lithium battery
composite cathode film, belonging to the technical field of battery
cathode materials. In order to solve the problems that
sintering aids are required being added and the
internal resistance of the interface is high in the prior art, the present invention provides a preparation method of a
solid state
lithium battery
composite cathode film. The method comprises the steps of: performing uniform mixing and ball milling of active
cathode particles and LLZO
solid electrolyte particles in proportion, then dryingthe mixture to obtain
composite cathode powder body particles, wherein the
mass content of the LLZO solid
electrolyte particles in the composite
cathode powder body particles is 5.0-35wt%; mixing thecomposite cathode particles, a binder, adhesives, a dispersing agent, a
plasticizer and a
solvent to form a composite cathode
slurry; and performing
tape casting of the composite cathode
slurry to prepare a composite cathode blank film, performing
drying and rubber discharging of the composite cathode blank film, and performing low-temperature
sintering processing at a temperature of 650-850 DEG Cto obtain a composite cathode film. The preparation method of the
solid state lithium battery composite cathode film can effectively improve the interface densification, can reduce the
interface impedance and can reduce the interface
charge transfer resistance.