The C─S/C═S Bonds Synergistically Modify Porous Hollow‐Carbon‐Nanocages Anode for Durable and Fast Sodium‐Ion Storage

Abstract Sulfur doping in carbonaceous anode is a popular method to improve the sodium storing performance. Regulating the C/S bond effect of carbon atom with doped sulfur atom could understand and develop superior carbonaceous anode for sodium‐ion batteries. Therefore, this study designed porous hollow carbon nanocages with synergistically‐doped C/S bonds (C‐S/C = S) by secondary‐sulfidation. The secondary‐sulfidation is conducive to the different bond formation of sulfur atom with carbon skeleton and adjust the structure via removed other groups. Thus, the C‐S/C = S anode with synergistically C‐S and C = S bonds delivered a reversible capacity of 307 mAh g‐1 at 1.0 A g⁻¹ with initial coulomb efficiency of 80.15%, a stable cycle life of 2000 cycles, and a fast charge capability of 186 mAh g⁻¹ at 20.0 A g⁻¹ in sodium‐ion batteries. Through characterization and simulation results, the doped C‐S/C = S bonds creates more active sites and ion diffusion channels in carbon skeleton for enhancing the fast and durable kinetics of sodium‐ion. This work provides deep insights into C/S bonds effect of carbon anode material for developing fast charge stability sodium‐ion batteries.