Interface Reconstruction in Bi/MoSSe Heterostructure Toward Fast‐Chargeable Sodium‐Ion Batteries

ABSTRACT The construction of metal/two‐dimensional semiconductor heterostructure comprising alloy‐type and conversion‐type electrode holds promise for achieving fast‐charging sodium‐ion batteries. However, interfacial instability and inefficient charge transfer remain critical challenges that hinder the practical implementation of this approach. Herein, we propose an interface reconstruction strategy to regulate interfacial coupling in Bi/MoSSe heterostructure with triple sodium storage mechanisms. The participation of sulfur and selenium induces interface reconstruction of metallic Bi, forming a stabilized Bi─S/Se interfacial phase between the Bi layer and the MoSSe monolayer. The interfacial phase enlarges the van der Waals (vdW) gap, introduces delocalized electronic states, and establishes a continuous charge transport pathway, thereby improving structural robustness and enhancing reaction kinetics. Consequently, the reconstructed Bi/MoSSe anode delivers a high reversible capacity of 556.8 mAh g −1 at 0.2 A g −1 , ultrahigh rate capability with a capacity of 238.7 mAh g −1 at 30 A g −1 , and excellent cycling stability. A full cell achieves an energy density of 232.3 Wh kg −1 and 80.5% capacity retention after 750 cycles. This work provides a novel design paradigm toward fast‐charging energy storage devices via an interface reconstruction strategy based on the rational design of metal/semiconductor heterojunctions.