Template‐Free Construction of Self‐Supported Sb Prisms with Stable Sodium Storage

Abstract Antimony (Sb) is a promising anode material for sodium‐ion batteries owing to its large capacity of 660 mAh g⁻¹. However, its practical application is restricted by the rapid capacity decay resulted from a large volume expansion up to 390% upon Na alloying. Herein, construction of a self‐supported Sb array that has enough space allowing for effective accommodation of the volume change is reported. The array of Sb prisms is directly grown on a Cu substrate via a template‐free electrodeposition, followed by mild heating to consolidate the structural integrity between Sb and Cu. The resulting 3D architecture endows the Sb array with excellent sodium storage performance, exhibiting a reversible capacity of 578 mAh g⁻¹ and retaining 531 mAh g⁻¹ over 100 cycles at 0.5 C. The potential of Sb array in sodium‐ion full cells by pairing it with a Na_0.67(Ni_0.23Mg_0.1Mn_0.67)O₂ cathode is further demonstrated. This full cell affords a specific energy of 197 Wh kg⁻¹ at 0.2 C and a specific power of 1280 W kg⁻¹ at 5 C. Considering its low cost and scale‐up capability, the template‐free route may find extensive applications in designing electrode architectures.