Plasma-engineered organic dyes as efficient polysulfide-mediating layers for high performance lithium-sulfur batteries

Abstract

Lithium-sulfur (Li-S) batteries have attracted extensive attention as a promising energy storage technology owing to their high theoretical capacity and energy density coupled with high cost efficiency. Despite these advantages, Li-S batteries still face problems in the shuttling behavior of soluble lithium polysulfides and the electrically insulating nature of sulfur, which has motivated considerable efforts toward developing conductive nanomaterials to improve electrochemical performances. In this study, microporous N, S dual-doped carbon materials based on a basic dye compound, methylene blue, were prepared via plasma engineering and carbonization process. Experimental and theoretical investigations revealed that an introduction of the carbon coated separators, denoted as PPMB interlayers, in Li-S batteries resulted in reduced cell polarization and effectively alleviated the lithium polysulfide shuttling behavior, leading to a high specific capacity of 1,329 mAh g−1 and retained specific capacity of 669 mAh g−1 after 100 cycles at 0.3C. This work highlights the potential application of this heteroatom-doped carbon material in Li-S batteries, as well as the viability of dye compound-derived carbon materials in energy storage devices.