Nitrogen-Doped carbon coupled FeNi3 intermetallic compound as advanced bifunctional electrocatalyst for OER, ORR and zn-air batteries

Developing OER&ORR bifunctional electrocatalysts has great significance for promoting the green energy conversion and storage technologies. Herein, nitrogen doped carbon coupled FeNi3 intermetallic compound (FeNi3@NC) is designed and constructed by a super facile route. Rich defects, multiple active centers and strong synergistic effect allow FeNi3@NC with superior OER&ORR performance in alkaline environments. It exhibits an ultralow overpotential (Eover) of 277 mV at 10 mA/cm2 for OER, and a high half-wave potential (E1/2) of 0.86 V for ORR which outperform commercial Pt/C electrocatalysts. As a result, the ΔE (ΔE = Eover,OER – E1/2,ORR) value of 0.65 V largely surpasses Pt/C-IrO2 noble metal benchmarks (ΔE = 0.73 V). Furthermore, density function theory calculations are performed to probe its electrocatalytic mechanism. As expected, the peak power density and energy density of FeNi3@NC based rechargeable Zn-air battery reaches 139 mW/cm2 at 234 mA/cm2 and 915 Wh kg−1 at 10 mA/cm2, respectively, with excellent stability. Our exploration provides a guideline for synthesis of advanced bifunctional electrocatalyst.