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This paper compares the oxygen reduction on four MnO2‐based air cathodes assembled in home‐made electrochemical cells, with some particular observations on α‐MnO2 cathode. The results show that the catalytic activity decreases in the following order: electrolytic MnO2 (EMD) > natural MnO2 (NMD) > β‐MnO2 > α‐MnO2. The maximum power density of the zinc‐air battery with EMD as the catalyst reaches up to 141.8 mW cm−2 at the current density of 222.5 mA cm−2, which is about 60%, 20% and 10% higher than that of α‐MnO2 (90.0 mW cm−2 at 120.3 mA cm−2), β‐MnO2 (121.5 mW cm−2 at 150.4 mA cm−2) and NMD (128.2 mW cm−2 at 207.8 mA cm−2), respectively. It is believed that its unique crystal structure and biggest BET surface area make EMD have the smallest charge transfer resistance (Rct), thus EMD has the highest activity.

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