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(−1) at 0.5 A g(−1) and provides an excellent rate performance for long-term cycling (197 mA h g(−1) at 2.0 A g(−1) 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.