Adhesive Sulfide Solid Electrolyte Interface for Lithium Metal Batteries

Abstract

All solid-state Li metal batteries have drawn extensive attention because of the limited side reaction and consequent safety character. The applications of Li metal anodes are indispensable for realizing high energy density but still face many obstacles. One of the critical issues is the contact failure of the solid/solid interface. The rigid interface between a sulfide electrolyte and Li anode cannot afford the volume variation during cycling. Herein, we design an adhesive solid-state electrolyte film, which is supported by hot melt adhesive porous membranes for anode protection. The Li symmetric cells and all solid-state batteries based on adhesive electrolyte layers all exhibit enhanced long cyclic stability and suppressed voltage polarization. The peel strength tests confirm that the electrolyte layers decorated with adhesive components can offer intimate Li metal/electrolyte physical contact and withstand the volume variation of the Li anode. The adhesion force from porous membranes is believed to play a vital role in maintaining solid-solid interfacial contact stability. This work gives a new insight for interface engineering in all solid-state Li metal batteries.