Oxygen Reduction Reaction Catalysts for Zinc‐Air Batteries Featuring Single Cobalt Atoms in a Nitrogen‐Doped 3D‐Interconnected Porous Graphene Framework

Abstract

Single‐atom catalysts (SACs) with high activity and efficient atom utilization for oxygen reduction reactions (ORRs) are imperative for rechargeable Zinc‐air batteries (ZABs). However, it is still a prominent challenge to construct a noble‐metal‐free SAC with low cost but high efficiency. Herein, a novel nitrogen‐doped graphene (NrGO) based SAC, immobilized with atomically dispersed single cobalt (Co) atoms (Co‐NrGO‐SAC), is reported for ORRs. In this 3D NrGO, the Co‐N4 sites endow high‐efficiency ORR activity, and the 3D‐interconnected porous architectures of NrGOs guarantee numberous active sites accessibility. Compared to commercial Pt/C catalyst (≈5.8 mA cm−2), as‐prepared Co‐NrGO‐SACs presents considerable limiting current density of ≈5.9 mA cm−2, prominent half‐wave potential of ≈0.84 V, onset potential of ≈1.05 V, and as well as superior methanol resistance. Particularly, ZABs with Co‐NrGO‐SACs deliver remarkable power density (≈240 mW cm−2), super durability of over 233 h at 5 mA cm−2, outperforming noble‐metal‐based benchmarks. This work provides an effective noble‐metal free carbon‐based SAC nano‐engineering for superdurable ZABs.