Electrocatalysts for Zinc–Air Batteries Featuring Single Molybdenum Atoms in a Nitrogen‐Doped Carbon Framework

• Published in: Advanced materials (Weinheim) 2023-09, Vol.35 (35), p.e2302625-n/a
• Main Authors: Balamurugan, Jayaraman, Austeria, P. Muthu, Kim, Jun Beom, Jeong, Eun‐Suk, Huang, Hsin‐Hui, Kim, Do Hwan, Koratkar, Nikhil, Kim, Sang Ouk
• Format: Article
• Language: English
• Subjects: Catalysts; Chemical reactions; Chemical reduction; Core-shell structure; core–shell interface; Electrocatalysts; Electronegativity; Graphene; interfacial engineering; Materials science; Metal air batteries; Molybdenum; Nanoparticles; Nitrogen; oxygen evolution reaction; Oxygen evolution reactions; oxygen reduction reaction; Oxygen reduction reactions; Rechargeable batteries; single‐atom catalysts; Zinc-oxygen batteries; zinc–air batteries
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202302625

Bifunctional catalysts can facilitate two different electrochemical reactions with conflicting characteristics. Here, a highly reversible bifunctional electrocatalyst for rechargeable zinc–air batteries (ZABs) is reported featuring a “core–shell structure” in which N‐doped graphene sheets wrap around vanadium molybdenum oxynitride nanoparticles. Single Mo atoms are released from the particle core during synthesis and anchored to electronegative N‐dopant species in the graphitic shell. The resultant Mo single‐atom catalysts excel as active oxygen evolution reaction (OER) sites in pyrrolic‐N and as active oxygen reduction reaction (ORR) sites in pyridinic‐N environments. ZABs with such bifunctional and multicomponent single‐atom catalysts deliver high power density (≈376.4 mW cm−2) and long cycle life of over 630 h, outperforming noble‐metal‐based benchmarks. Flexible ZABs that can tolerate a wide range of temperatures (−20 to 80 °C) under severe mechanical deformation are also demonstrated Synthesis of multicomponent core–shell structures presents a versatile route to produce bifunctional molybdenum‐based single‐atom‐catalysts. Zinc–air batteries with such multicomponent single‐atom catalysts deliver high power density (≈376.4 mW cm−2) and a long cycle life of over 630 h, significantly outperforming noble‐metal‐based benchmarks.