Lithium Metal Ingrowth Toward a Porous Structure via Coble Creep along Lithium-Carbon Interface Without Ionic Conductors

Abstract

All-solid-state batteries (ASSBs), equipped with highly ion-conductive sulfide solid electrolytes and utilizing lithium plating/stripping as anode electrochemistry, suffer from 1) chemical vulnerability of the electrolytes with lithium and 2) physical growth of lithium to penetrate the electrolytes. By employing an ordered mesoporous graphitic carbon (OMGC) framework between a sulfide electrolyte layer and a copper current collector in ASSB, the concerns by are addressed 1) minimizing the chemically vulnerable interface (CVI) between electric conductor and solid electrolyte, and 2) allowing lithium ingrowth toward the porous structure via Coble creep, a diffusional deformation mechanism of lithium metal along the lithium-carbon interface. The void volume of the framework is fully filled with lithium metal, despite ionic pathways not being provided separately, even without additional lithiophiles, when an enough amount of lithium is allowed to be plated. The consecutive mechanism of OMGC lithiation - lithium plating - Coble creep worked for ASSB operation, suggesting a feasible possibility of zero volume change ASSBs with three-dimensionally porous carbon frameworks.