Enhanced Stability and Narrowed D‐Band Gap of Ce‐Doped Co3O4 for Rechargeable Aqueous Zn‐Air Battery. (21st December 2022)

• Record Type: Journal Article
• Authors: Qian, Jinmei; Liu, Xin; Zhong, Chenglin; Xu, Guofu; Li, Haijing; Zhou, Wanhai; You, Bo; Wang, Fei; Gao, Daqiang; Chao, Dongliang
• Is Part Of: Advanced functional materials. Volume 33:Number 9(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-21
• Subjects: aqueous batteries -- Ce‐doped Co 3O 4 -- d‐band center -- octahedral‐site occupation -- Zn‐air batteries; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202212021
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: It remains challenging to achieve further breakthroughs in the development of durable bifunctional air cathode electrocatalysts for increasing the cycling life of rechargeable Zn‐air battery (RZAB). Herein, d‐band gap narrowing strategy is proposed to significantly boost the electrocatalytic activity and stability of spinel Co3 O4 for both oxygen reduction and evolution reactions. In situ Raman spectroscopy finds that the Ce atom substitution can significantly improve the durability and corrosion resistance of electrocatalysts in harsh alkaline electrolytes. Synchrotron X‐ray absorption fine structure reveals that the Co 3+ /Co 2+ ratio of Co3 O4 can be tuned with Ce introduction, which is beneficial to optimize the adsorption/desorption of the intermediates over Cooh 3+ active sites. Density functional theory calculations further confirm the reduced gap between Co d‐band and O p‐band centers, increased electrical conductivity, together with the deepened valence band maximum of Co sites in Ce‐doped Co3 O4 . Thereby, the optimized RZAB with Ce‐Co3 O4 delivers excellent long‐term durability (290 h) and large specific capacity (876.3 W h k g Z n − 1 $Wh\;kg_{Zn}^{{\bm{ - }}1}$ ), which possesses great prospects in all‐solid‐state flexible RZAB devices. Abstract : The p/d band center and electrocatalytic stability of Co3 O4 are tuned by doping rare‐earth metal of Ce. The kinetics of oxygen reduction and evolution reactions is optimized for rechargeable aqueous Zn‐air battery.