Entropy‐Engineered Layered Double Hydroxide Derived High‐Entropy Alloy Cathodes for Zinc–Air Batteries Under High Depth‐of‐Discharge

Strong bifunctional electrocatalysts capable of sustaining both oxygen reduction (ORR) and oxygen evolution (OER) at high depths-of-discharge are crucial for practical rechargeable zinc-air batteries (ZABs). Here, we present a novel MnFeCoNiCu high-entropy alloy uniformly anchored on nitrogen-doped carbon nanotubes, derived from a high-entropy layered double hydroxide precursor. A dicyandiamide-assisted pyrolysis enabled simultaneous CNT growth, nitrogen doping, and alloy nanoparticle formation, yielding a single-phase face-centered cubic HEA at 900°C (HEA 900). Structural analyses confirmed homogeneous atomic-level metal dispersion, significant lattice distortion, and strong metal-carbon coupling, providing abundant active sites and enhanced conductivity. Owing to these synergistic effects, HEA 900 exhibited excellent bifunctional activity with an OER overpotential of 475 mV at 10 mA/cm², an ORR half-wave potential of 0.81 V, and a low ΔE of 0.89 V. The HEA-based ZAB showed a near-theoretical specific capacity of 801 mAh/g_Zn, and a peak power density of 186 mW/cm². The cell's remarkable reversibility and mechanical robustness were confirmed by extended cycling under high DOD (up to 10 h per cycle) and impressive energy efficiency over 3325 cycles. Flexible gel-polymer ZABs further demonstrated robust mechanical and electrochemical durability, highlighting this HELDH-derived HEA strategy as a promising paradigm for entropy-engineered catalysts in high-performance ZABs.