In-site coupling of NiFe layered double hydroxides with N-doped carbon nanosheets on carbon cloth as integrated cathode for rechargeable Zn-air batteries

Exploring low-cost, high catalytic activity and high durability dual-function catalysts is critical for rechargeable Zn-air batteries to promote the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) processes. In this paper, integrated air electrodes have been successfully assembled by in-site coupling of NiFe layered double hydroxide (LDH) nanosheets with N-doped carbon nanosheet arrays on carbon cloth (NiFe LDH@N-CNSs@CC). The electrochemical performance shows that the hierarchical structure provides abundant sites for the catalytic OER and ORR processes. In addition, the rechargeable Zn-air battery using NiFe LDH@N-CNSs@CC as a cathode can maintain a stable voltage gap of 0.90 V over 300 hours of cycling at a current density of 5 mA cm(-2), demonstrating excellent cycling stability, which is better than that of commercial Pt/C + RuO2 catalyst.