Solvothermal‐induced synthesis of in‐situ carbon‐coated antimony nanoparticles as an anode material for sodium‐ion batteries

Abstract Sodium‐ion batteries (SIBs) are attracting increasing attention due to their low cost of raw materials and high potential as an alternative to lithium‐ion batteries in energy storage systems. Owing to its favorable reaction potential (0.6 V vs Na/Na + ) and high reversible capacity (660 mAh g −1 ), antimony (Sb) has been extensively studied as an anode material for SIBs. However, the poor cyclability of a pure Sb anode, induced by the mechanical stress mechanism, hinders its application. Herein, carbon microspheres catalyzing the in‐situ polymerization and coating of Sb are developed through a “solvothermal‐induced” synthesis method. During the solvothermal process in the presence of carbon microspheres, SbCl 3 can react with ethylene glycol to generate an organic‐inorganic hybrid precursor. This precursor can be further reduced into carbon‐coated Sb with controllable carbon content. Benefiting from an in‐situ coating process that buffers the volume change of Sb, the as‐prepared carbon‐coated Sb anode shows improved Na‐storage performance. It achieves a capacity of 330 mAh g −1 (based on the total mass of Sb and carbon) at 0.1 A g −1 and exhibits good cycling stability at 1 A g −1 . This work contributes to a facile approach for preparing a carbon‐coated metallic anode for SIBs.