Atomic Cu dispersed ZIF-8 derived N-doped carbon for high-performance oxygen electrocatalysis in Zn-air battery

Abstract Single-atom catalysts have attracted widespread attention in recent years due to their high atom utilization and excellent catalytic performance, particularly, in oxygen electrocatalysis. Herein, we report to use ZIF-8 as precursor, which was annealed and subsequently mixed with melamine and transition metal salt to finally synthesize Cu-atoms modified N-doped carbon (NC) catalysts, which exhibited excellent oxygen reduction reaction activity and kinetic performance in alkaline solution. The constructed rechargeable Zn-air battery using Cu-NC and benchmark Pt/C catalyst supported on carbon fiber paper as the cathode and anode, respectively, exhibited super good long-term stability with remaining voltaic efficiency of 56% at a charge/discharge current density of 5 mA cm⁻² after running 250 cycles (ca. 42 h). Moreover, the power density was as high as 104.5 mW cm⁻² at 0.65 V, and such three Zn-air batteries connected in series could light up 34 LED bulbs (2 V and 1.5 W for each) used for constructing a figure of ‘USTL’ for at least 12 h. This research provides a facile method on the synthesis of efficient and cost-effective ORR electrocatalysts in renewable energy storage and conversion systems.