Gibaek Lee

Rechargeable, cost‐efficient aqueous aluminium‐ion batteries (AAIBs) possess abundant trivalent charge carriers with high volumetric energy densities. However, the rapid and irreversible formation of Al 2 O 3 passivation films on aluminium‐ion (AI) anodes while using aqueous electrolytes limits their development. Herein, Zn metal was used as the anode, and Al 3+ was locally deposited on the Zn anode during charging. V 6 O 13 with a mixed vanadium state of V 4+ /V 5+ was chosen as the cathode because of its efficient ion diffusion (solid state) and high electron conductivity. The Zn−Al/3 M Al(OTF) 3 /V 6 O 13 cell exhibited high current density and excellent long‐term cycling stability, demonstrating a very high specific capacity of ∼100 mAh g −1 at a current density of 3 A g −1 and Coulombic efficiency of ∼100 % with reversible stability over 1400 cycles. Furthermore, the V 6 O 13 cathode exhibited a multi‐ionic capacity of Zn 2+ ‐ and H + ‐ions during the Al deposition/dissolution reaction in AAIBs, demonstrating high safety and stability for fast charging.