Surface-dominated ultra-stable sodium and potassium storage enabled by N/P/O tri-doped porous carbon

Sodium-ion batteries and potassium-ion batteries are attracting considerable attention for basic research and practical applications. However, the anode side is the dominative bottleneck which restricts the stability and fast charge/discharge capability of SIBs and PIBs. Heteroatom doping is considered to be an effective method to further improve the electrochemical performance of carbon materials. Herein, the N/P/O tri-doped porous carbon is obtained through an extremely simple soft chemistry route along with in-situ pyrolysis. The obtained NPO-C-800 delivers the highly reversible capacity of 301.2 and 213.5 mA h g(-1) after 100 and 2000 cycles at 0.1 and 1.0 A/g in sodium-ion batteries. It is worth mentioning that the high specific capacity could still be retained with negligible capacity decay after 12,000 cycles at 10 A/g, which should be ascribed to the surface-dominated storage mechanism. Additionally, NPO-C-800 presents a highly reversible specific capacity of 269.4 mA h g(-1) at 0.1 A/g after 100 cycles and excellent cycling stability at 1.0 A/g in potassium-ion batteries. The fast and stable surface-dominated pseudocapacitive sodium and potassium storage enabled by heteroatom doping represents a promising strategy to boost the performance of carbon anodes towards high-power rechargeable batteries.