P2/O3 phase-integrated Na0.7MnO2 cathode materials for sodium-ion rechargeable batteries
| Autor: | M. Alam Khan, Gi-Hyeok Lee, Yong-Il Kim, Yong-Mook Kang, Dongwook Han |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Mechanical Engineering Sodium Metals and Alloys chemistry.chemical_element 02 engineering and technology Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Cathode 0104 chemical sciences law.invention Chemical engineering chemistry Mechanics of Materials law Oxidation state Phase (matter) Materials Chemistry Calcination Crystallization 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 771:987-993 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2018.09.033 |
| Popis: | We describe a phase-integrated P2-Na0.7MnO2/O3-NaMnO2 sodium manganese oxide (Na0.7MnO2) cathode material for sodium-ion rechargeable batteries. By changing the crystallization cooling rate after the calcination of P2/O3-Na0.7MnO2, the ratio between the two different (P2-Na0.7MnO2 and O3-NaMnO2) phases (and the Mn4+/Mn3+ ratio) in the Na0.7MnO2 material could be controlled. The P2/O3-Na0.7MnO2 sample prepared by fast cooling contains the optimum content of the two principal phases and showed excellent electrochemical performance because of the synergy between the fast kinetics of the P2-Na0.7MnO2 phase and high capacity of the O3-NaMnO2 phase. The stability of the layered crystal structure of Na0.7MnO2 was also improved by increasing the portion of the P2-Na0.7MnO2 phase, which has a higher average oxidation state of Mn compared to that in O3-NaMnO2; this suppressed the Jahn–Teller distortion during cycling. |
| Databáze: | OpenAIRE |
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