02473nas a2200277 4500008004100000022001400041245010900055210006900164260000800233490000700241520149100248653001801739653003001757653003301787653002501820653002101845653004501866653003401911100003001945700002001975700001701995700001602012700001802028700002402046856012502070 2025 eng d a1613-681000aDefect-rich CoFe-alloy with engineered carbon support for high-performance rechargeable Zn-air batteries0 aDefectrich CoFealloy with engineered carbon support for highperf cSEP0 v213 a

Defect-rich CoFe-alloy with engineered carbon support is synthesized as a bifunctional cathode, coupled with a modified electrode fabrication technique, for rechargeable zinc-air batteries (RZABs). The CoFe(2:1)/N-rGCNT-catalyst is synthesized by annealing graphene oxide (GO), cobalt and iron acetate, and melamine, leading to the in situ formation of CoFe alloy-encapsulated CNTs. This resulted in a unique layer-separated Fe-rich skin@CoFe alloy decorated nitrogen-doped graphene (NGr) with CoFe-encapsulated CNTs. The interplay of line defects, enhanced conductivity, and electronic modulation underpins electrocatalyst's performance. Electrochemical analysis revealed an onset potential of 955 mV vs RHE, a half-wave potential of 835 mV vs RHE for oxygen reduction reaction (ORR) and an overpotential of 340 mV for oxygen evolution reaction (OER), yielding a Delta E of 0.73 V, comparable to the reported catalysts. The 3D X-ray microtomography simulations suggest improved air permeability of CoFe(2:1)/N-rGCNT facilitates easier gas diffusion, contributing in better device performance. The RZAB with CoFe(2:1)/N-rGCNT-cathode exhibited a peak power density of 171.3 mW cm(-)2, surpassing 140.8 mW cm(-)2 obtained from a cell based on Pt/C-cathode. The Co/N-rGCNT-based battery achieved a stable discharge profile at 10 mA cm(-)2 with a specific capacity of 650 mAh g(-)(1)Zn, and in rechargeable mode, achieved 140 h of high-rate charge-discharge cycling capability.

10a3D tomography10aN-doping10aalloy encapsulated structure10adevice demonstration10agrain boundaries10aoxygen reduction and evolution reactions10arechargeable zinc-air battery1 aKharabe, Geeta, Pandurang1 aBarik, Sidharth1 aTorris, Arun1 aMaria, Anit1 aKumar, Yogesh1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/defect-rich-cofe-alloy-engineered-carbon-support-high-performance-rechargeable-zn-air