Biomimetic Wood‐Like 3D Porous MXene/NiFeMnO _x Nanocomposite for Enhanced Oxygen Evolution Reaction and Zinc‐Air Battery Stability

ABSTRACT The widespread adoption of rechargeable zinc‐air batteries (ZAB) is hindered by slow oxygen evolution reaction (OER) kinetics and poor durability of cathode catalysts. This study uses flake‐like MXene nanosheets as a base material and creates a 3D porous scaffold with vertical channels via an ice templating method. Transition metal oxides (NiFeMnO x ) were deposited onto this MXene framework and annealed, resulting in a nanocomposite with a high surface area and mechanical stability. The 3D structure promotes efficient ion infiltration at the electrode–electrolyte interface, enhancing oxygen mass transport and reaction kinetics. The NiFeMnO x catalyst shows bifunctional catalytic activity, reducing overpotentials and improving cycling stability for both oxygen reduction and evolution reactions. The cathode material exhibits an overpotential of only 325 mV at 10 mA cm −2 and a low charge transfer resistance of 25 Ω. A liquid ZAB with this MXene/NiFeMnO x cathode demonstrated a cycling lifespan of 120 h, outperforming commercial Pt/C‐RuO 2 air electrodes. This approach combines material optimization with a 3D porous structure, improving mass transport and charge transfer, thus advancing ZAB performance.