H2S + SO2 produces water-dispersed sulfur nanoparticles for lithium-sulfur batteries

Abstract

Sulfur shows totally opposite faces in environmental and energy issues. Sulfur containing gases, H2S and SO2, are dominant air pollutants, while sulfur plays as the clean energy carrier for Li-Sulfur (Li-S) batteries. Herein, through confining the gaseous comproportionation reaction in water, between H2S and SO2 that normally produces uncontrollable aggregates, we develop a completely clean approach to convert the air pollutants into water-dispersed sulfur nanoparticle (WDS). The WDS is contaminant-free, size-controllable, and more promisingly solution processable, and is thus ideal for achieving solution hybridization with other materials for various applications. As a typical example, an aqueously fabricated WDS/carbon nanotube composite delivers the theoretical capacity of sulfur at 0.5Ag−1, and a capacity of ~750 mAh g−1 even at a high current density of 5.0Ag−1. In addition to the normal use of sulfur as cathode, a new-concept WDS/carbon interlayer with a low sulfur content has been designed to inhibit the shuttling of polysulfides, greatly improving the cycling performance of the Li-S battery. The proposed approach gives a good example to turning pollutants into clean energy carriers by green chemistry.