Confining Sulfur in Porous Carbon by Vapor Deposition to Achieve High-Performance Cathode for All-Solid-State Lithium-Sulfur Batteries

All-solid-state lithium-sulfur batteries (ASLBs) have the potential to achieve high energy density because of sulfur's high theoretical capacity (1672 mAh g(-1)) while alleviating persistent polysulfide shuttling inherent to lithium-sulfur batteries based on liquid organic electrolyte. However, the homogenization of sulfur, carbon, and solid electrolyte is a challenge to achieving high-performance cathodes for ASLBs. Herein, we demonstrate a promising sulfur-carbon composite with high sulfur content (71.4-83.3%) prepared using a sulfur vapor deposition (SVD) approach to show enhanced discharge specific capacities, rate performance, and cycling stability, outperforming conventional sulfur liquid deposition (SLD) and sulfur solid deposition (SSD) approaches. A higher discharge specific sulfur capacity of 1792.6 mAh g(-1) has been achieved at 0.1 degrees C and 60 degrees C with improvement ascribed to smaller particle size and more homogeneous and deeply confined sulfur in sulfur-carbon composite, in contrast to 1619.2 and 1329.3 mAh g(-1) for samples prepared by conventional SLD and SSD approaches, respectively.

Automated summary

All-solid-state lithium-sulfur batteries have the potential to achieve high energy density, and the use of sulfur-carbon composite materials can improve discharge specific capacities, rate performance, and cycling stability, outperforming conventional sulfur liquid deposition and sulfur solid deposition methods. Higher sulfur content and more uniform sulfur distribution are key factors in achieving higher performance.