At present, the continuously growing environmental pollution and energy depletion greatly inspire the development of renewable energy technologies including Li-ion batteries , fuel cells and metal-air batteries , etc., which have emerged as systems of commercial and notable scientific interests. Among them, the rechargeable metal-air batteries have obtained the increasing concerns due to the features in environment, cost and particularly in the potential application to replace the traditional Li-ion batteries which theoretical capacity is largely limited by the electrode materials (to date, the theoretical capacity has nearly reached) . Typically, owing to the use of organic and aqueous electrolytes the metal-air batteries are divided into two groups, like Li-air batteries and Zn-air batteries, respectively. The former still needs breakthroughs in the issue of reaction products block subsequent reactions ; the latter is regarded as the safer and more reliable system, whose electrochemical reaction rate largely relies on the electrocatalytic processes of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at cathodes .