Rationally Designed Solution-Processible Conductive Carbon Additive Coating for Sulfide-based All-Solid-State Batteries

Abstract

Sulfide-based all-solid-state batteries (ASSBs) haveemerged aspromising candidates for next-generation energy storage systems owingto their superior safety and energy density. A conductive agent isnecessarily added in the cathode composite of ASSBs to facilitateelectron transport therein, but it causes the decomposition of thesolid electrolyte and ultimately the shortening of lifetime. To resolvethis dilemmatic situation, herein, we report a rationally designedsolution-processible coating of zinc oxide (ZnO) onto vapor-growncarbon fiber as a conductive agent to reduce the contact between thecarbon additive and the solid electrolyte and still maintain electronpathways to the active material. ASSBs with the carbon additive withan optimal coating of ZnO have markedly improved cycling performanceand rate capability compared to those with the bare conductive agent,which can be attributed to hindering the decomposition of the solidelectrolytes. The results highlight the usefulness of controllingthe interparticle contacts in the composite cathodes in addressingthe challenging interfacial degradation of sulfide-based ASSBs andimproving their key electrochemical properties.