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

Abstract

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.