| Autor: |
Amaha, Kaoru, Kobayashi, Wataru, Akama, Shota, Mitsuishi, Kazutaka, Moritomo, Yutaka |
| Předmět: |
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| Zdroj: |
Physica Status Solidi - Rapid Research Letters; Jan2017, Vol. 11 Issue 1, pn/a-N.PAG, 6p |
| Abstrakt: |
O3-NaFe1/2Co1/2O2 shows initial capacity of 160 mAh/g and an average operating voltage of 3.1 V (vs. Na) with good cyclability, and is a promising candidate of the cathode materials for sodium-ion secondary batteries (SIBs). Here, we found that the cyclability of the slowly-cooled sample is much worse than that of quenched one, even though the former sample keeps the O3-type structure. The energy dispersive X-ray spectroscopy (EDX) images suggest that the slow-cooled sample (Na x Fe1- yCo y O2) is inhomogeneous in the Fe concentration (1 - y), perhaps triggered by the Na deficiency (1 - x). We ascribed the poor cyclability in the slowly-cooled sample to the concentration inhomogeneity (Δ y). The Δ y is further responsible for the fluctuation of the lattice constants ( a and c), as revealed by the Williamson-Hall plot. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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