NiFeMo Nanoparticles Encapsulated within Nitrogen‐Doped Reduced Graphene Oxide as Bifunctional Electrocatalysts for Zinc‐Air Batteries

Abstract

Abstract Rechargeable metal‐air batteries (MABs) have emerged as promising candidates for portable energy storage technologies because of their favorable energy/power density, safety, and cost‐effectiveness. However, the lack of advanced bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) restricts the commercial realization of rechargeable MABs. Herein, we developed a facile fabrication route to prepare N‐doped graphene oxide encapsulating nanoparticles of a ternary NiFe metal oxide (NiFeMo@N‐rGO) serving as an efficient bifunctional catalyst. The obtained NiFeMo@N‐rGO bifunctional catalyst demonstrates a comparable catalytic reactivity when compared to precious metal catalysts in alkaline electrolytes regarding ORR/OER performance (ORR: half‐wave potential of 0.82 V; OER: overpotential of 330 mV; ▵E: 0.73 V at 10 mA cm−2). The assembled zinc‐air batteries (ZABs) catalyzed by NiFeMo@N‐rGO exhibit a high power density of 120 mW cm−2 and a capacity of 721 mAh gZn−1, coupled with long‐term durability of over 200 h. This contribution paves a practical avenue to prepare efficient bifunctional catalysts for superior ZABs.

Keywords

• NiFeMo nanoparticles
• reduced graphene oxide
• oxygen reduction
• oxygen evolution
• Zn-air batteries