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

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 degrees 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 degrees C after sulphur solution impregnation. Composite electrodes were prepared by impregnating both sulphur and solid electrolyte solutions into the interior of the porous carbon and drying them, and the composites were applied to all solid-state lithium-sulphur batteries.