Entropy and defect coupling in high-entropy hexagonal materials mitigates coulombic interaction for superior aluminum...

High-entropy materials promise exceptional structural stability and tunable chemistry, yet their application in aluminum batteries (ABs) remains hampered by sluggish ion transport and poorly understood entropy and defect interactions. Here, we combine the high-entropy strategy with the layered double hydroxide (LDH) concept to design a two-dimensional (2D) high-entropy hexagonal material with engineered oxygen vacancies (V_O-HEH) to directly tackle these bottlenecks in Al storage. Entropy-driven elemental diversity induces strong orbital hybridization between metals of disparate electronegativity, creating a delocalized electronic environment that accelerates charge transfer. The oxygen vacancies (V_O) formed in parallel are demonstrated to suppress coulombic interaction and open rapid migration channels, thereby overcoming the intrinsic kinetic barriers of Al³⁺ insertion. The V_O-HEH cathode delivers improved capacity (177 mAh g^-1 at 0.5 A g^-1) and enhanced cycling stability (102 mAh g^-1 over 1400 cycles at 3.0 A g^-1) enabled by the synergistic effects of entropy stabilization, defect regulation, and multi-electron redox. This work presents a well-designed single-phase high-entropy cathode and elucidates how entropy and defect effects modulate the electronic structure and govern the electrochemical behavior of ABs.