A series of iron-doped nickel cobalt oxide/activated carbon (Fe0.1Ni0.9Co2O4/AC) composites with various ratios of activated carbon were synthesised via a microwave-assisted hydrothermal method. The introduction of activated carbon significantly promotes the catalytic activity of Fe0.1Ni0.9Co2O4 for the oxygen evolution reaction (OER); meanwhile the complete coverage of nanoparticulate Fe0.1Ni0.9Co2O4 onto activated carbon particles prevents the carbon oxidation, leading to improved cycling durability of a zinc-air cell. Scanning electron microscopy images shows a good protective coverage of the nanoparticulate Fe0.1Ni0.9Co2O4 onto the activated carbon particles. Rotating disk electrode voltammetry and electrochemical impedance spectroscopic results reveal that the OER overpotential and charge-transfer resistance of the Fe0.1Ni0.9Co2O4 electrocatalyst are substantially lowered by the introduction of activated carbon. With respect to the cycling stability, Fe0.1Ni0.9Co2O4/1.0 wt%AC and Fe0.1Ni0.9Co2O4/1.5 wt%AC composites maintain excellent activity for 80 h in a rechargeable zinc-air battery, due to the uniformly protective coverage of metal oxide on activated carbon. Furthermore, the Fe0.1Ni0.9Co2O4/3.7 wt%AC composite was examined in a prolonged rechargeable zinc-air battery test for 120 h and the charge-discharge voltage gap was negligibly enlarged (0.02 V increment after 120 h), which showed their potential as electrocatalysts for long-term energy storage systems.