Hierarchical Porous Sb Films on 3D Cu Substrate Have Promise for Stable Sodium Storage

We report a hierarchical porous Sb film deposited on a three-dimensional (3D) Cu substrate as an efficient anode for sodium storage. Fabrication of a porous Sb film involves co-electrodeposition of Zn–Sb alloys on a 3D Cu substrate and sequential dealloying of Zn, giving rise to a mesoporous Sb structure. The hierarchically porous Sb film manifests a superior electrochemical feature when serving as a self-supported electrode for sodium storage. It affords a high reversible capacity of 624 mAh g–1, a retention of 575 mAh g–1 over 200 cycles at 330 mA g–1, and a rate capability of 514 mAh g–1 at 3300 mA g–1, outperfoming most recently reported Sb based materials. Moreover, the full cell consisting of a hierarchical Sb anode and Na3V2(PO4)3 cathode affords a specific energy of 149 mWh g–1, suggesting that this hierarchical design may open new perspectives for high-performance battery materials.