Optimized Electrode/Electrolyte Interface Engineering for Dendrite‐Free Al Anode and Self‐Activated Graphite Cathode

Abstract Rechargeable aluminum batteries (RABs) have garnered attention owing to their impressive theoretical capacity, outstanding safety features, and abundant Al reserves, thereby positioning them as a potential alternative and supplement to fixed energy storage. Nonetheless, RABs still suffer from issues, such as poor anode stability stemming from the corrosivity of the chloral aluminate ionic liquid electrolyte (ILs) and subpar wettability of the cathode. To address these issues, the proposed electrolyte interfacial engineering involves the nonionic surfactant (F127) as an interfacial optimizer in ILs, simultaneously modulating the anode–electrolyte and cathode–electrolyte interfaces. Systematic experiments and theoretical analyses validate that F127 preferentially adsorbs on the electrode surface, forming a dense and uniform adsorption layer. The F127 layer can effectively mitigate the corrosion of ILs on the Al anode and regulate the current density to achieve uniform Al deposition. Furthermore, F127 enhances the wettability between the cathode and ILs, preventing the collapse of the graphite structure and enhancing the active material's utilization. The Al//FG full battery assembled with F127 modifying ILs (F127‐0.5) is able to retain a specific capacity of 104.9 mAh g −1 after 1600 cycles, which is higher than ILs (69.0 mAh g −1 ). This electrolyte interface modification strategy holds considerable practical significance for achieving long‐lifespan and high‐capacity RABs.