An efficient and durable non-precious metal catalyst based on Co/Fe/CoFe-CNAs@NHCNFs for bifunctional oxygen electrocatalysis in flexible Zn-Air batteries

Co/Fe/CoFe-CNAs@NHCNFs has been synthesised through a template-free approach that exploits the synergistic effect of Co, Fe, and N-doped hollow carbon nanofibres. This resulting Co/Fe/CoFe-CNAs@NHCNFs catalysts display enhanced electrical conductivity and an expanded active surface area. The Co/Fe/CoFe-CNAs@NHCNFs catalyst exhibits remarkable electrocatalytic performance and achieves an oxygen evolution reaction (OER) an overpotential of only 1.55 V (10 mA cm⁻²), which shows excellent electrochemical properties. It is evident that the collaborative reaction among Co, Fe, and N refines the electronic configuration, thereby increasing the efficiency of electron transfer and strengthening the catalytic activity.The incorporation of N-doping enriches the catalyst with an augmented array of catalytic centers., which are highly effective for facilitating the oxygen reduction reaction (ORR) and OER, consequently lowering an activation energy required for these reactions. Its electrochemical performance is more remarkable than conventional Pt/C. The liquid zn-air battery based on Co/Fe/CoFe-CNAs@NHCNFs exhibites an open-circuit voltage reaching 1.396 V, the peak power density achieved was 253 mW cm⁻². Under a constant current discharge condition of 10 mA cm⁻², the battery exhibited over 60 hours of good cycling stability with no significant performance degradation. The solid-state rechargeable Zn-air batteries (RZABs) based on Co/Fe/CoFe-CNAs@NHCNFs catalyst demonstrate exceptional energy storage capacity and stability, exhibiting promising potential for practical applications