Abstract: Antimony (Sb) is considered as an ideal anode for sodium-ion batteries due to its high theoretical sodium storage capacity of 660 mAh g?1. However, its commercial application is impeded by significant volume changes during charge-discharge cycling, which lead to the pulverization and shedding of the active materials. To address these issues, this study employs a simple electro-deposition method to fabricate an InSb alloy on a three-dimensional porous copper current collector with micrometer-sized pores. The introduced indium (In) element effectively suppresses the aggregation of Sb electrodes, the occurrence of irreversible reactions, and thus enhances the initial Coulombic efficiency. Meanwhile, the three-dimensional porous structure provides a large specific surface area and abundant active sites, which not only increase the sodium storage capacity and ion diffusion rate but also offer buffer enough space for volume expansion, thereby enhancing the structural stability of the material. Under the synergistic effect of the In element and the three-dimensional porous structure, the 3D Cu@InSb electrode exhibits a high initial Coulombic efficiency of 80.7 %, good cycling stability (a capacity retention rate of 97.6 % after 400 cycles at a current density of 10 A g?1), and excellent rate performance (a specific capacity of 225.4 mAh g?1 at a high current density of 20 A g?1).

Key words: Sodium-ion battery, Anode, InSb alloy, Three-dimensional porous copper, Electrodeposition