Single Atomic Cu‐C 3 Sites Catalyzed Interfacial Chemistry in Bi@C for Ultra‐Stable and Ultrafast Sodium‐Ion Batteries

Regulating interfacial chemistry at electrode‐electrolyte interface by designing catalytic electrode material is crucial and challenging for optimizing battery performance. Herein, a novel single atom Cu regulated Bi@C with Cu−C 3 site (Bi@SA Cu−C) have been designed via the simple pyrolysis of metal‐organic framework. Experimental investigations and theoretical calculations indicate the Cu−C 3 sites accelerate the dissociation of P−F and C−O bonds in NaPF 6 ‐ether‐based electrolyte and catalyze the formation of inorganic‐rich and powerful solid electrolyte interphase. In addition, the Cu−C 3 sites with delocalized electron around Cu trigger an uneven charge distribution and induce an in‐plane local electric field, which facilitates the adsorption of Na + and reduces the Na + migration energy barrier. Consequently, the obtained Bi@SA Cu−C achieves a state‐of‐the‐art reversible capacity, ultrahigh rate capability, and long‐term cycling durability. The as‐constructed full cell delivers a high capacity of 351 mAh g −1 corresponding to an energy density of 265 Wh kg −1 . This work provides a new strategy to realize high‐efficient sodium ion storage for alloy‐based anode through constructing single‐atom modulator integrated catalysis and promotion effect into one entity.