A New Concept of an Air-Electrode Catalyst for Li2O2 Decomposition Using MnO2 Nanosheets on Rechargeable Li-O2 Batteries
| Autor: | Hidenobu Shiroishi, Shiro Seki, Daniel Streich, Taichi Fujinami, Yusuke Tachikawa, Erik J. Berg, Morihiro Saito, Petr Novák, Shinpei Kosaka |
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| Rok vydání: | 2017 |
| Předmět: |
Battery (electricity)
Charge cycle Materials science Scanning electron microscope General Chemical Engineering Nanotechnology 02 engineering and technology Overpotential 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Chemical reaction 0104 chemical sciences Nanomaterials Catalysis Chemical engineering Electrode Electrochemistry 0210 nano-technology |
| Zdroj: | Electrochimica Acta. 252:192-199 |
| ISSN: | 0013-4686 |
| Popis: | To improve the charge/discharge properties of a rechargeable Li-O 2 battery (LAB), we synthesized a new air-electrode catalyst composed of MnO 2 nanosheets (Mn-NSs) and Ketjen Black (KB), i.e., a KB-comp. Mn-NS catalyst. The composite catalyst was synthesized by electrostatically restacking the nanomaterials in a colloidal solution with Li + and its electro-catalytic activity as an air-electrode for a LAB test cell was evaluated. The KB-comp. Mn-NS catalyst exhibited excellent performance, especially for oxidation of Li 2 O 2 deposited on the surface of the air-electrode during the charging process, which led to enhanced reversibility of the Li 2 O 2 deposition/decomposition reaction during the discharging/charge cycles. Evidence of these reactions was investigated and confirmed by X-ray diffraction analysis and scanning electron microscopy-energy dispersive X-ray spectroscopy. The Li 2 O 2 was deposited and decomposed more homogeneously at the air-electrode with the KB-comp. Mn-NS catalyst than that with only KB. Consequently, the composite catalyst significantly reduced the overpotential and improved the cycleability up to the 27th cycle, even at 0.40 mA. |
| Databáze: | OpenAIRE |
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