Iron‐Doped CoNi‐MOF‐Derived Carbon Coated CoNi Alloy Nanoparticles as Bifunctional Oxygen Electrocatalysts for Rechargeable Zinc–Air Batteries

Abstract Cost‐effective highly efficient and robust bifunctional oxygen electrocatalysts are essential for commercialization of rechargeable zinc air batteries (ZABs). Doping is a simple and effective defect engineering approach for enhancement of electrocatalytic activities. Herein, Fe‐doped, carbon‐coated CoNi alloy nanoparticle catalysts, Fe‐CoNi@C, derived from CoNi bimetallic metal‐organic frameworks, are developed as outstanding bifunctional oxygen electrocatalysts for rechargeable ZABs. Fe‐CoNi@C achieves an ultrasmall voltage gaps at 10 mA cm −2 (Δ E 10 ) of 0.668 V, significantly smaller than 0.767 V of (Pt/C + IrO 2 ). The Fe‐CoNi@C based ZAB delivers a high peak power density of 307.7 mW cm −2 at a high current density of 521 mA cm −2 , largely surpassing the (Pt/C + IrO 2 ) based one (199.7 mW cm −2 at 310 mA cm −2 ), and exhibits excellent cycling stability with a stable operation of up to 1800 cycles (600 h), much longer than 940 cycles (313 h) achieved by the (Pt/C + IrO 2 ) based one.