Production method for all-solid-state battery

A method for producing an all-solid-state battery having a solid electrolyte layer between a positive electrode layer and a negative electrode layer, the method comprising:

• coating or impregnating at least one of the positive electrode layer and the negative electrode layer with a solid electrolyte solution obtained by dissolving a boron hydride compound serving as a solid electrolyte in a solvent, wherein the obtained solution includes no undissolved boron hydride compound;
• and
• removing the solvent from the coated or impregnated solid electrolyte solution and causing the solid electrolyte to precipitate on at least one of the positive electrode layer and the negative electrode layer,
• wherein the solvent comprises at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, propanenitrile, acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide, and
• wherein the boron hydride compound consists of at least one selected from the group consisting of LiBH4, a LiBH4-LiI-based material, 3LiBH4—LiI, a LiBH4—P2S5-based material, 9LiBH4—P2S5, a LiBH4—P2I4-based material, 9LiBH4—P2I4, 85LiBH4-15P2I4, Li2B12H12, Li2B10H10, LiCB11H12, and LiCB9H10.