NiCo2 O4 -Based Nanosheets with Uniform 4 nm Mesopores for Excellent Zn-Air Battery Performance
© 2020 Wiley-VCH GmbH.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 32(2020), 39 vom: 01. Okt., Seite e2001651 |
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| Weitere Verfasser: | , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2020
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| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article Zn-air batteries mesoporous nanosheets oxygen evolution reaction oxygen vacancies valence electron regulation |
| Zusammenfassung: | © 2020 Wiley-VCH GmbH. Herein, a strategy is reported for the fabrication of NiCo2 O4 -based mesoporous nanosheets (PNSs) with tunable cobalt valence states and oxygen vacancies. The optimized NiCo2.148 O4 PNSs with an average Co valence state of 2.3 and uniform 4 nm nanopores present excellent catalytic performance with an ultralow overpotential of 190 mV at a current density of 10 mA cm-2 and long-term stability (700 h) for the oxygen evolution reaction (OER) in alkaline media. Furthermore, Zn-air batteries built using the NiCo2.148 O4 PNSs present a high power and energy density of 83 mW cm-2 and 910 Wh kg-1 , respectively. Moreover, a portable battery box with NiCo2.148 O4 PNSs as the air cathode presents long-term stability for 120 h under low temperatures in the range of 0 to -35 °C. Density functional theory calculations reveal that the prominent electron exchange and transfer activity of the electrocatalyst is attributed to the surface lower-coordinated Co-sites in the porous region presenting a merging 3d-eg -t2g band, which overlaps with the Fermi level of the Zn-air battery system. This favors the adsorption of the *OH, and stabilized *O radicals are reached, toward competitively lower overpotential, demonstrating a generalized key for optimally boosting overall OER performance |
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| Beschreibung: | Date Revised 07.12.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.202001651 |