Preparation of carbon–sulphur composite electrodes by solution impregnation and application to all-solid-state lithium–sulphur batteries

Abstract

All-solid-state lithium–sulphur batteries have attracted attention because of their high theoretical capacity and suppression of polysulphide dissolution in organic liquid electrolytes. In this study, sulphur–carbon composites were prepared by impregnating sulphur and a solid electrolyte into the pores of carbon particles using the liquid phase. First, sulphur was impregnated into porous carbon using sulphur-dissolved in toluene and the solvent was subsequently removed. Then, sulphur–carbon composites with and without heat treatment at 155 °C were prepared. Solid electrolyte (SE, Li₆PS₅Cl) was impregnated into the sulphur–carbon composites using an ethanol solution of Li₆PS₅Cl. All-solid-state lithium–sulphur batteries were fabricated using the solid electrolyte–sulphur–carbon composites and Li₂S–P₂S₅ solid electrolyte. The batteries showed almost the same capacity despite heating and not heating at 155 °C after sulphur solution impregnation.