Expediting Sodium Energy of Hard Carbon by Cation/Anion Co‐Interfering Chemistry

Abstract Hard carbon promises commercial prospect as the anode materials of Na‐ion batteries, however, it remains a huge challenge to refine the carbon microstructure for advanced sodium energy. Herein, a powerful design strategy of cation/anion co‐interfering chemistry is demonstrated to expedite the sodium storage capability of resin‐based hard carbon. A desirable carbon microstructure rich in closed pores and pseudographitic crystallites is synergetically developed by cation‐triggered activation and anion‐induced curvature of graphene nanosheets, which creates abundant active sites and fast Na + diffusion channels. Impressively, the as‐optimized hard carbon presents an enhanced reversible capacity of 349.3 mAh g −1 , outstanding rate capability of 221.6 mAh g −1 at 2 A g −1 , as well as superior lifetime over 5000 cycles. The pore‐induced kinetic characteristics and charge storage mechanism are systematically unveiled by theoretical calculations and in situ techniques. This work confers a fresh design methodology for rationally regulating the carbon microstructure for high‐capacity and superb‐rate sodium storage.