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

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-cost-performance and electrochemical activities bifunctional non-precious 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 (Delta E=0.761 V) for oxygen reduction and oxygen evolution reaction. Furthermore, compared to commercial Pt/C-RuO2 in RZABs, BZIF-C@LDH displays a superior energy density (1033 Wh kg(-1)), which is close to the theoretical energy density (1086 Wh kg(-1)). This work provides a straightforward and inexpensive strategy for the synthesis of excellent and practicable bifunctional catalysts for RZABs.