Method for producing lithium solid state battery

Abstract

A method for producing a lithium solid state battery having a solid electrolyte membrane with high Li ion conductivity, in which firm interface bonding is formed on both sides of the membrane, comprising steps of: a membrane-forming step of forming CSE1 not containing a binder, composed of a sulfide solid electrolyte material, on a cathode active material layer by an AD method and ASE1 not containing a binder, composed of a sulfide solid electrolyte material, on an anode active material layer by an AD method, and a pressing step of forming SE1 with the CSE1 and the ASE1 integrated by opposing and pressing the CSE1 and the ASE1, wherein the SE1 such that an interface between the CSE1 and the ASE1 disappeared is formed by improving denseness of the CSE1 and the ASE1 in the pressing step.

What is claimed is: 
     
         1 . A lithium solid-state battery comprising:
 a cathode active material layer,   a cathode-side solid electrolyte membrane not containing a binder, composed of a sulfide solid electrolyte material, and formed on the cathode active material layer,   an anode active material layer, and   an anode-side solid electrolyte membrane not containing a binder, composed of a sulfide solid electrolyte material, and formed on the anode active material layer,   wherein the cathode-side solid electrolyte membrane and the anode-side solid electrolyte membrane are opposed,   the cathode-side solid electrolyte membrane and the anode-side solid electrolyte membrane have a disappeared interface when observed by a scanning electron microscope, and   the cathode-side solid electrolyte membrane and the anode-side solid electrolyte membrane have an interface with the length of 5% or less to the total length.   
     
     
         2 . The lithium solid-state battery according to  claim 1 , wherein a total membrane thickness of the cathode-side solid electrolyte membrane and the anode-side solid electrolyte membrane is within a range of 1 μm to 50 μm.