Rechargeable zinc-air batteries (ZAB) with a high theoretical energy density of 1086 Wh kg−1, have received tremendous research attention. However, the practical application of ZABs is still limited by high polarization and poor energy efficiency (low power density) due to the sluggish 4 electrons (e−)/oxygen (O2) kinetics over the air electrode. Here, a noble-metal-free FeNxC electrocatalyst is developed via a one-pot approach, which provides a high density of the oxygen reduction reaction (ORR) active site and facilitates the ORR kinetics. Accordingly, the as-assembled Zn-air battery displayed a low charge–discharge voltage gap of 0.71 V at 10 mA cm−2, a remarkable peak power density as high as 181.2 mW cm−2, as well as the long-term durability for hundreds of hours, among the top level of those reported previously. Our work provides a major boost for the practical application of Zn-air battery in the future.