Sulfur-rich composite cathodes using carbon replica frameworks for all-solid-state lithium–sulfur batteries

Abstract

In this study, high-sulfur-containing carbon replica (sulfur-rich S-CR) composites were prepared using a melt-diffusion method. Melt diffusion under vacuum enabled the introduction of four times the weight ratio of sulfur into the mesopores of a carbon replica (CR). The obtained sulfur-rich S-CR exhibited an initial discharge capacity of 700 mAh g_sulfur⁻¹, indicating the low utilization of sulfur in the composite. The classification of the particle sizes of the solid electrolyte and CR contributed to the improvement in electrochemical performance. An initial discharge capacity of over 1,200 mAh g⁻¹ was confirmed for the S-CR composite using the smaller solid electrolyte and CR prepared via a dry classification process. An analysis of the effect of the additives indicated that the rational design of electronic and ionic conduction pathways is required for higher cycle performance when using sulfur-rich S-CRs.