Carbon-Nanotube-Bridging Strategy for Integrating Single Fe Atoms and NiCo Nanoparticles in a Bifunctional Oxygen Electrocatalyst toward High-Efficiency and Long-Life Rechargeable Zinc-Air Batteries

The development of highly efficient and robust bifunctional electrocatalysts for oxygen reduction (ORR) and evolution reactions (OER) is the key issue for realizing high-performance and long-life rechargeable zinc-air batteries (ZABs). However, it is still a great challenge to integrate independent ORR and OER sites in a catalyst with high activity. Here, a carbon nanotube-bridging strategy is proposed to synthesize such a bifunctional oxygen electrocatalyst enriched with highly active single-atom Fe sites for the ORR and high-performance nanosized NiCo hydroxides for the OER. Consequently, the developed catalyst shows a small overpotential difference of 0.686 V. When used as an oxygen electrode catalyst, the corresponding ZAB exhibits a large power density of 219.5 mW cm(-2), a small charge-discharge voltage gap of 0.72 V at 10 mA cm(-2), and outstanding discharge-charge durability without attenuation after more than 700 cycles. This work proposes a new idea to realize multifunctional catalysts and drives the practical application of ZABs.

Automated summary

This study proposes a carbon nanotube-bridging strategy to synthesize a highly efficient oxygen electrocatalyst for the development of high-performance and long-life rechargeable zinc-air batteries. The results show that the developed catalyst exhibits good electrochemical performance and cycle stability.