Dynamic electrocatalyst with current-driven oxyhydroxide shell for rechargeable zinc-air battery

• Published in: Nature communications Vol. 11; no. 1; p. 1952
• Main Authors: Deng, Ya-Ping, Jiang, Yi, Liang, Ruilin, Zhang, Shao-Jian, Luo, Dan, Hu, Yongfeng, Wang, Xin, Li, Jun-Tao, Yu, Aiping, Chen, Zhongwei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23-04-2020; Nature Publishing Group; Nature Portfolio
• Subjects: 140/146; 639/638/161/886; 639/638/161/891; Batteries; Bimetals; Configurations; Electrocatalysts; Enlargement; Humanities and Social Sciences; Maturation; Metal air batteries; multidisciplinary; Oxygen; Rechargeable batteries; Science; Science (multidisciplinary); Spectroscopy; Zinc; Zinc-oxygen batteries
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15853-1

Recent fruitful studies on rechargeable zinc-air battery have led to emergence of various bifunctional oxygen electrocatalysts, especially metal-based materials. However, their electrocatalytic configuration and evolution pathway during battery operation are rarely spotlighted. Herein, to depict the underlying behaviors, a concept named dynamic electrocatalyst is proposed. By selecting a bimetal nitride as representation, a current-driven “shell-bulk” configuration is visualized via time-resolved X-ray and electron spectroscopy analyses. A dynamic picture sketching the generation and maturation of nanoscale oxyhydroxide shell is presented, and periodic valence swings of performance-dominant element are observed. Upon maturation, zinc-air battery experiences a near two-fold enlargement in power density to 234 mW cm
−2
, a gradual narrowing of voltage gap to 0.85 V at 30 mA cm
−2
, followed by stable cycling for hundreds of hours. The revealed configuration can serve as the basis to construct future blueprints for metal-based electrocatalysts, and push zinc-air battery toward practical application.
Interest in rechargeable Zn-air batteries has been renewed in recent years, however, their oxygen electrocatalysts remain not fully understood. Here the authors reveal the presence of a current-driven oxyhydroxide shell in a so-called dynamic eletrocatalyst that enables optimized battery performance.