Inbuilt photoelectric field of heterostructured cobalt/iron oxides promotes oxygen electrocatalysis for high-energy-efficiency zinc-air batteries

The practical application of zinc-air batteries (ZABs) is limited by the large overpotentials generated by the sluggish kinetics of oxygen electrocatalysis at air electrodes. To address this challenge, we report a photocathode composed of Fe2O3/Co3O4 mixed metal oxides for photo-assisted rechargeabl...

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Bibliographic Details
Published in:Applied catalysis. B, Environmental Environmental, 2024-11, Vol.357, p.124315, Article 124315
Main Authors: Zhu, Ting, Xia, Chenfeng, Wu, Bo, Pan, Jun, Yang, Hongran, Zhang, Weibin, Xia, Bao Yu
Format: Article
Language:English
Subjects:
Energy efficiency
Heterostructure
Oxygen electrocatalysis
Photocathodes
Zn-air battery
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Summary:The practical application of zinc-air batteries (ZABs) is limited by the large overpotentials generated by the sluggish kinetics of oxygen electrocatalysis at air electrodes. To address this challenge, we report a photocathode composed of Fe2O3/Co3O4 mixed metal oxides for photo-assisted rechargeable ZABs. Owing to the formation of Fe2O3/Co3O4 heterostructures with abundant oxygen vacancies (Vox), the air electrode exhibited a high surface photovoltage (SPV) of 220 mV based on the contact potential difference (CPD) recorded before and after light irradiation, corresponding to a very high specific SPV of 44 kV m−1. Consequently, the photo-rechargeable ZABs incorporating this Fe2O3/Co3O4 air photocathode exhibit a low charge potential of 1.6 V under light irradiation. Furthermore, these ZABs demonstrate a remarkable increase in energy efficiency, from 64 % to 78 %, coupled with a high specific capacity of 712.3 mAh g−1 and excellent stability over a span of 60 hours. This achievement underscores the potential for harnessing light energy in the next generation of ZABs, suggesting the promise of a brighter future for energy storage technologies. [Display omitted] •Homogeneous scattering of Fe2O3 within Co3O4 matrix facilitates the separation and migration of photoinduced charger carriers.•The SPV of the typical Fe2O3/Co3O4 photoelectrode can reach 44 kV m−1.•The charging potential of the Fe2O3/Co3O4-30 is reduced from 1.83 to 1.6 V, revealing a photoenhancement of 12.5 %.
ISSN:0926-3373
1873-3883
DOI:10.1016/j.apcatb.2024.124315