Facile Fabrication of NiFe Double Hydroxide on Carbon Matrix Composites as an Efficient Oxygen Electrocatalyst for Rechargeable Zn‐air Batteries

Abstract

Air cathodes with highly effective oxygen reduction and oxygen evolution reaction performance are crucial for commercial applications in rechargeable Zn-air batteries (RZABs). Commercial catalysts are expensive and scarce, which restricts their practical applications. Therefore, the design of high-costperformance and electrochemical activities bifunctional nonprecious metal catalysts is urgent. The bifunctional catalyst (BZIF-C@LDH) combining NiFe-LDH and ZIF-8&ZIF-67 derivative (BZIF-C) was readily prepared with a co-precipitation approach.As expected, the obtained BZIF-C@LDH exhibits outstanding bifunctional performance (ΔE = 0.761 V) for oxygen reduction and oxygen evolution reaction. Furthermore, compared to commercial Pt/C-RuO 2 in RZABs, BZIF-C@LDH displays a superior energy density (1033 Wh kg À 1 ), which is close to the theoretical energy density (1086 Wh kg À 1 ). This work provides a straightforward and inexpensive strategy for the synthesis of excellent and practicable bifunctional catalysts for RZABs.