Regulation of Atomic Fe-Spin State by Crystal Field and Magnetic Field for Enhanced Oxygen Electrocatalysis in Rechargeable Zinc-Air Batteries

Yibo Wang; Pengyu Meng; Zhaohui Yang; Min Jiang; Jian Yang; Huanxin Li; Jiao Zhang; Baode Sun; Chaopeng Fu

doi:10.1002/anie.202304229

Regulation of Atomic Fe-Spin State by Crystal Field and Magnetic Field for Enhanced Oxygen Electrocatalysis in Rechargeable Zinc-Air Batteries

Angew Chem Int Ed Engl. 2023 Jul 10;62(28):e202304229. doi: 10.1002/anie.202304229. Epub 2023 May 31.

Authors

Yibo Wang¹, Pengyu Meng¹, Zhaohui Yang¹, Min Jiang¹, Jian Yang¹, Huanxin Li², Jiao Zhang¹, Baode Sun¹, Chaopeng Fu¹

Affiliations

¹ School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, China.
² Department of Chemistry, University of Oxford, Oxford, UK.

PMID: 37139572
DOI: 10.1002/anie.202304229

Abstract

Highly-active and low-cost bifunctional electrocatalysts for oxygen reduction and evolution are essential in rechargeable metal-air batteries, and single atom catalysts with Fe-N-C are promising candidates. However, the activity still needs to be boosted, and the origination of spin-related oxygen catalytic performance is still uncertain. Herein, an effective strategy to regulate local spin state of Fe-N-C through manipulating crystal field and magnetic field is proposed. The spin state of atomic Fe can be regulated from low spin to intermediate spin and to high spin. The cavitation of d_xz and d_yz orbitals of high spin Fe^III can optimize the O₂ adsorption and promote the rate-determining step (*O₂ to *OOH). Benefiting from these merits, the high spin Fe-N-C electrocatalyst displays the highest oxygen electrocatalytic activities. Furthermore, the high spin Fe-N-C-based rechargeable zinc-air battery displays a high power density of 170 mW cm^-2 and good stability.

Keywords: Oxygen Evolution; Oxygen Reduction; Single Atom Catalyst; Spin State; Zn-Air Battery.

Abstract

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