PURPOSE: To obtain a lithium negative electrode having high discharge utilization and uniform discharge performance by dispersing lithium and solid electrolyte in hydrocarbon solvent having high boiling point at high temperature to uniformly mix lithium and lithium ion conductive solid electrolyte.

CONSTITUTION: Hydrocarbon solvent having high boiling point for mixing lithium and lithium ion conductive solid electrolyte is required to have higher boiling point than the melting point of lithium (about 186°C). For his purpose, decalin (b.p. 194.6°C) or "Amsco 450" made at American Mineral Spirits Corp. in the U.S.A. is used. Lithium and lithium ion conductive solid electrolyte are put into high boiling point hydrocarbon solvent, and they are heated with gently stirring to melt lithium, then stirring rate is increased to disperse lithium in solid electrolyte, or lithium is melted and dispersed in hydrocarbon solvent, then solid electrolyte powder is dispersed therein.