Composite negative electrode material, composite negative electrode pole piece, all-solid-state battery and preparation method

The invention relates to a composite negative electrode material, a composite negative electrode pole piece, an all-solid-state battery and a preparation method. The composite negative electrode material is formed by compounding a negative electrode active material with a coating on the surface and a polymer electrolyte. The composite negative electrode plate comprises the composite negative electrode material. The preparation method of the composite negative pole piece comprises the following steps: ball-milling and sintering the coating and the negative active material in a solvent to obtain the negative active material with the coating, mixing the negative active material with the polymer to obtain the composite negative material, mixing the composite negative material with the conductive agent and the adhesive, and coating a current collector with the mixture to obtain the composite negative pole piece. The all-solid-state battery comprises the composite negative pole piece, a positive pole piece and a so