Evaluating the influences of the sulfur content in precursors on the structure and sodium storage performances of carbon materials

As an efficient method to promote the electrochemical performances of carbon materials for sodium-ion batteries (SIBs), heteroatom (S, N, etc.) doping has attracted significant interest from researchers, and great efforts have been devoted to explore the functional mechanism of SIBs. Heteroatom doping enlarges the layer distance of carbon, provides more active sites, and enhances the conductivity for the promotion of sodium storage; however, the influences of heteroatom-containing precursors on the structures, morphologies and electrochemical sodium storage performances of carbon materials have rarely been explored. In this study, a series of S/N co-doped carbon materials (SNC) has been designed, and the influences of the S contents in precursors on the structures and morphologies of the carbon materials have been evaluated. Furthermore, the electrochemical sodium storage performances of the obtained materials have been investigated. With the introduction of S, the insertion/extraction behaviors of Na+ in the microcrystals of carbon materials were obviously enhanced. Meaningfully, the integrated influence of the precursor S content on the materials and sodium storage performances obtained in this study can contribute to the design and preparation of similar materials.