S-doped porous carbon anode with superior capacity for high-performance sodium storage.

Heterogeneous carbon-based materials with high porosity are attracting increased attention for energy storage due to their enhanced capacity and rate performance. Herein, we report a sulfur-doped porous carbon material, which is achieved by spray-drying and subsequent sulfuration. The porous structure can provide vast diffusive tunnels for the fast access of electrolytes and sodium ions. Also, the S-C bond increases the electrical conductivity of the carbon frameworks and offers excessive reaction sites for sodium-ion storage. The elaborated carbon architecture enables a high capacity of 370 mA h g at 0.5 A g and provides an excellent rate performance for long-term cycling (197 mA h g at 2.0 A g for 650 cycles). Considering the scalable and facile spray-pyrolysis preparation route, this material is expected to serve as a low-cost and environmentally friendly anode for practical sodium-ion batteries.