▎ 摘　　要

NOVELTY - A composite solid electrolyte comprises a polymer solid electrolyte, an electrolyte lithium salt and a lithium alloy inorganic filler. The sum of the weight of lithium salt and lithium alloy filler is not greater than 25 wt.% based on the total weight of the composite solid electrolyte. USE - The composite solid electrolyte is used in an all-solid-state battery (claimed). ADVANTAGE - The composite solid electrolyte has excellent electrochemical performance at room temperature, and provides a higher capacity and more ideal service life for all-solid-state batteries. The lithium alloy filler has lithium-ion conduction, electrochemical lithium supplement, stable to lithium metal, cheap raw material and simple preparation. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of a composite solid electrolyte, which involves (S1) mixing the polymer electrolyte and electrolyte lithium salt, dissolving the mixture in a solvent, and heating and stirring the mixture to obtain uniform viscous liquid, (S2) uniformly dispersing the prepared lithium alloy filler in a solvent to prepare slurry, mixing the slurry with the liquid and continuously heating and stirring, and (S3) pouring the mixed slurry on the surface of a mold or electrode, and vacuum drying; and (2) an all-solid battery, which comprises a composite positive electrode and a composite negative electrode. The composite electrode material contains the polymer electrolyte and lithium salt as in the composite solid electrolyte. The composite electrode material comprises 50-92 wt.%, preferably 75-90 wt.% positive or negative active material, 5-30 wt.%, preferably 10-20 wt.% polymer electrolyte as a binder, 2.5-5 wt.% electrolyte lithium salt, and 2.5-15 wt.% preferably 5-10 wt.% conductive additive. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a composite layered structure. NCM622 ternary material (1) SP conductive carbon black (2) PEO polymer electrolyte (3) Aluminum foil (4) Composite anode (5) Lithium-silicon alloy particles (6) Co-mixed polymer electrolyte (7) Composite solid electrolyte layer (8)