Co nanoparticles encapsulated in N-doped carbon nanofibers as bifunctional catalysts for rechargeable Zn-air battery

Rechargeable Zn-air battery (ZAB) still relies on the precious metal-based catalysts, whose high cost, supply scarcity and inferior durability largely hamper the large-scale application of ZAB. Herein, a non-noble-metal catalyst towards both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is successfully constructed by carbonizing metal-organic frameworks (MOB) functionalized electrospun nanofibers. The obtained bifunctional electrocatalyst shows good catalytic performance with comparable limiting diffusion current to PVC and comparable potential to RuO2, in particular, superior stability to both PVC and RuO2 towards ORR and OER. In view of the efficient bifunctional catalyst activity for ORR and OER, the obtained catalyst in ZAB displays high charge/discharge performance and long cycling stability, demonstrating great potential in grid-scale energy storage.