Ultrafast Strategy to Fabricate Sulfur Cathodes for High-Performance Lithium–Sulfur Batteries

Abstract

Based on the different dielectric properties of materials and the selective heating property of microwaves, the ultrafast (30 s) preparation of S-NiS₂@SP@Bitu as a cathode material for lithium-sulfur batteries was achieved using bitumen, sulfur, Super P, and nickel naphthenate as raw materials for the first time, under microwave treatment. NiS₂@SP@Bitu forms Li-N, Li-O, Li-S, and Ni-S bonds with polysulfide, which contributes to promoting the adsorption of polysulfide, reducing the precipitation and decomposition energy barrier of Li₂S, and accelerating the catalytic conversion of polysulfide, as result of inhibiting the "shuttle effect" and improving the electrochemical performance. S-NiS₂@SP@Bitu as the sulfur cathode material demonstrates outstanding rate performance (518.6 mAh g^-1 at 4C), and stable cycling performance. The lithium-sulfur battery with a sulfur loading of 4.8 mg cm^-2 shows an areal capacity of 4.6 mAh cm^-2. Based on the advantages of microwave selective and rapid heating, this method creatively realized that the sulfur carrier material was prepared and sulfur was fixed in it at the same time. Therefore, this method would have implications for the preparation of sulfur cathode materials.