Synergistic Multi-Element Strategy Enables SnSbMnBiTe High-Entropy Alloy Anode for Stable and Fast Sodium Storage

High-entropy alloys (HEAs), characterized by their multielement composition and elevated configurational entropy, offer significant potential as stable anode materials for sodium-ion batteries. Yet, their targeted design for sodium storage remains underexplored. Here, we develop a SnSbMnBiTe HEA anode via rational element selection and entropy engineering, integrating sodium-active elements (Sn, Sb, Bi, Te) with similar atomic properties and Mn as a stabilizing component. The resulting alloy achieves a high configurational entropy of 1.61 R, stabilizing its single-phase structure and uniform composition. Electrochemical tests demonstrate excellent performance, delivering 381.7 mAh g–1 after 80 cycles with 96.3% retention and sustaining 283.6 mAh g–1 at 5.0 A g–1. Dominant pseudocapacitive behavior and rapid charge transport underpin these results, while structural analyses confirm minimal swelling and a stable SEI layer. In full-cell configurations with Na3V2(PO4)3 cathode, the full cell delivers a stable capacity of 94.4 mAh g–1 after 300 cycles, maintaining nearly 100% Coulombic efficiency throughout. This study offers a viable strategy for designing high-performance high entropy alloy anodes and advancing durable sodium-ion battery technologies.