• • The HEO-Cr cathode (Fe0.6Co0.6Ni0.6Mn0.6Cr0.6O4) delivers a rate capability of 119.4 mAh g−1 at 10.0 A g−1, outperforming conventional metal-oxide cathodes in AAIBs, indicating superior electron transport kinetics.
• • Cycling stability is exceptional: over 95.1 mAh g−1 is retained after 500 cycles at 2.0 A g−1, demonstrating the high-entropy framework's effectiveness in mitigating structural degradation from Al3+ electrostatic repulsion.
• • The high-entropy strategy broadens the d-band and reduces electronic level degeneracy, as confirmed by DFT simulations, which is critical for facilitating rapid electron transport in multi-electron transfer reactions.
• • A phase transformation to a layered AlxMnO2 structure occurs during cycling, retaining the high-entropy skeleton, which contributes to long-term stability—a mechanism absent in conventional monometallic oxides that typically suffer sharp capacity decay.