Nickel Foam as a New Air Electrode Material to Enhance the Performance in Rechargeable Zn-Air Batteries

Abstract

Developing efficient air electrodes for improving the stability and power density of batteries plays a significant role in rechargeable Zn-air batteries. We here report a new air electrode by applying nickel foam (Ni foam) as support and the catalysts are sprayed on it. Therefore, NiCo2O4@Ni foam, FeCo2O4@Ni foam and MnCo2O4@Ni foam as new air electrodes are successfully established, which show superior stability in the discharge and charge processes and higher energy density than traditional carbon paper (CP) as supports. The improved Zn-air battery performances using NiCo2O4@Ni foam, FeCo2O4@Ni foam and MnCo2O4@Ni foam as air electrodes were attributed to the more abundant pore structure, good electrical conductivity, and high mechanical strength. Especially, the FeCo2O4@Ni foam air electrode owned the highest discharge power density of 483 mW cm-2 in a designed primary Zn-air battery, and the MnCo2O4@Ni foam air electrode owned the best stability of 648 cycles under 5 mA cm-2 current density for the rechargeable Zn-air battery.