Antimony nanoparticles encapsulated in three‐dimensional porous carbon frameworks for high‐performance rechargeable batteries

Abstract Antimony (Sb) is regarded as a potential candidate for next‐generation anode materials for rechargeable batteries because it has a high theoretical specific capacity, excellent conductivity and appropriate reaction potential. However, Sb‐based anodes suffer from severe volume expansion of > 135% during the lithiation–delithiation process. Hence, we construct a novel Sb@C composite encapsulating the Sb nanoparticles into highly conductive three‐dimensional porous carbon frameworks via the one‐step magnesiothermic reduction (MR). The porous carbon provides buffer spaces to accommodate the volume expansion of Sb. Meanwhile, the three‐dimensional (3D) interconnected carbon frameworks shorten the ion/electron transport pathway and inhibit the overgrowth of unstable solid‐electrolyte interfaces (SEIs). Consequently, the 3D Sb@C composite displays remarkable electrochemical performance, including a high average Coulombic efficiency (CE) of > 99%, high initial capability of 989 mAh·g −1 , excellent cycling stability for over 1000 cycles at a high current density of 5 A·g −1 . Furthermore, employing a similar approach, this 3D Sb@C design paradigm holds promise for broader applications across fast‐charging and ultralong‐life battery systems beyond Li + . This work aims to advance practical applications for Sb‐based anodes in next‐generation batteries.