Sulfur Encapsulation and Sulfur Doping Synergistically Enhance Sodium Ion Storage in Microporous Carbon Anodes

, respectively, and the ICE is as high as 72.3%. Moreover, the effect of nitrogen and sulfur on the improvement of electron/ion diffusion kinetics is resonantly demonstrated by density functional theory calculations. This synergistic preparation method may reveal a feasible thought for fabricating excellent-performance adsorption-type carbon materials for Na-ion batteries.