CERAMIC-SOFT COMPOSITES FOR SOLID-STATE SILICON ANODES

An anode composite (AC) for use in an anode for solid-state lithium batteries includes particles of a silicon active material, a carbon additive for electrical conductivity, and a solid electrolyte that combines solid elastic electrolyte (SEE) with a solid non-elastic electrolyte. The solid non-elastic electrolyte is a lithium thiophosphate or other ceramic lithium ion conductor and the SEE includes an ammonium or phosphonium ion closo-borate doped with a lithium salt. The SEE is diffused onto the combined particles uniformly by heating, where pressing achieves about 100% relative density at modest pressures. The anode displays high stability upon charge-discharge cycles of a solid-state lithium battery prepared with the AC layer, appearing to maintain stable intrinsic and extrinsic interfaces.