Unlocking the Power of Magnesium Batteries: Synergistic Effect of InSb‐C Composites to Achieve Superior Electrochemical Performance

Abstract Pure magnesium anode used in rechargeable magnesium batteries (RMB) exhibits high theoretical capacity but has been challenged by the passivation issue with conventional electrolytes. Alloy‐type anodes have the potential to surpass this issue and have attracted increasing attention. However, the kinetic performance and stabilities of conventional alloy anodes are still constrained. In this study, the InSb‐10%C anode is synthesized by a two‐step high‐energy ball milling process. The InSb‐10%C anode exhibits a remarkably high capacity of up to 448 mA h g⁻¹, significantly improved cycle performance (234 mA h g⁻¹ at 100 cycles) and rate performance (168 mA h g⁻¹ at 500 mA g⁻¹). The above‐mentioned superior performance of the InSb‐10%C anode for RMBs is attributed to the cellular graphitized amorphous carbon composite structure (CGA) which effectively refines the particle size and restricts the volume expansion. Additionally, the reduced surface electron density of InSb combined with the high conductivity resulting from graphitization enhances the Mg²⁺ diffusion performance. Notably, the InSb‐10%C anode demonstrates good compatibility with conventional halogen‐free salt ether‐based electrolytes in the full battery configuration.