Unlocking Entropy‐Stabilized Multinary Metal‐Phosphide for High‐Performance Sodium Storage Anode Material

Abstract Alloy materials are promising anode materials for sodium‐ion batteries (SIBs) due to their high capacity. Nevertheless, significant volumetric variation during the charging and discharging process poses a critical challenge for their practical applications. Drawing inspiration from the concept of high‐entropy materials (HEMs), a multinary metallic phosphide is designed through a combination of high‐energy ball milling and the incorporation of carbon nanotubes (SnSbCuBiP 4 ‐CNT). This approach not only enhances the rapid sodium‐ion transport but also effectively mitigates the issue of volume expansion. As an anode material, SnSbCuBiP 4 ‐CNT exhibits a low sodiation potential at ≈0.4 V and an exceptional capacity of 904.1 mAh g −1 . Even at an ultrahigh current density of 10 A g −1 , 642.1 mAh g −1 can still be provided. Furthermore, when integrated into a full cell with Na 2 VTi(PO 4 ) 3 (NVTP) cathode, which can be achieved an energy density of 189.3 Wh kg −1 and a power density of 7322 W kg −1 . These results demonstrate that SnSbCuBiP 4 ‐CNT is a promising anode material for SIBs, characterized by its high configurational entropy and outstanding electrochemical performance. This work provides an exquisite perspective for the exploration of multinary metallic phosphide, paving the way for the development of next‐generation energy storage.