High Performance of Sulfur/Carbon Cathode Synthesized via a Facile Green Microwave Approach

Sulfur has a specific capacity of 1675 mAhg-1 as a lithium battery cathode, but its rapid capacity decay due to the migration of dissolved polysulfides presents a major challenge for commercialization. Most approaches in the past few decades have focused on impregnating sulfur into a carbon host via various harsh, time-consuming, and costly carbonization techniques. In this context, sublimed sulfur is introduced into a commercial carbon via microwave treatment in minutes for the first time. The formation of chemical bonding between sulfur and carbon induced by microwave irradiation is proven by thermogravimetric, Raman, X-ray photoelectron spectroscopy, and electrochemical analyses. When being cycled at 0.2 C, the resulting composites with 55.5 wt % sulfur loading exhibit 912 and 531 mAhg-1 in the 1st and the 600th cycles, respectively, corresponding to a fairly low fading rate of about 0.07%cycle-1. This convenient, cheap, and green route shortens the synthesis process, lowers the cost, and stands for an advancement for potential large-scale industrialization.