期刊
NATURE CHEMISTRY
卷 10, 期 3, 页码 288-295出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/NCHEM.2923
关键词
-
资金
- Engineering and Physical Sciences Research Council (EPSRC)
- EPSRC [EP/K040375/1]
- Swiss National Science Foundation through the Sinergia network Mott Physics Beyond the Heisenberg model
- NCCR MARVEL
- European Community's Seventh Framework Programme (FP7) [290605]
- Office of Science, Office of Basic Energy Sciences, US Department of Energy [DE-AC02-05CH11231]
- EPSRC [EP/M009394/1, EP/L019469/1, EP/M009521/1] Funding Source: UKRI
- Engineering and Physical Sciences Research Council [EP/L019469/1, EP/M009521/1, 1655688, EP/M009394/1] Funding Source: researchfish
The search for improved energy-storage materials has revealed Li-and Na-rich intercalation compounds as promising high-capacity cathodes. They exhibit capacities in excess of what would be expected from alkali-ion removal/reinsertion and charge compensation by transition-metal (TM) ions. The additional capacity is provided through charge compensation by oxygen redox chemistry and some oxygen loss. It has been reported previously that oxygen redox occurs in O 2p orbitals that interact with alkali ions in the TM and alkali-ion layers (that is, oxygen redox occurs in compounds containing Li+-O(2p)-Li+ interactions). Na-2/3[Mg0.28Mn0.72]O-2 exhibits an excess capacity and here we show that this is caused by oxygen redox, even though Mg2+ resides in the TM layers rather than alkali-metal (AM) ions, which demonstrates that excess AM ions are not required to activate oxygen redox. We also show that, unlike the alkali-rich compounds, Na-2/3[Mg0.28Mn0.72]O-2 does not lose oxygen. The extraction of alkali ions from the alkali and TM layers in the alkalirich compounds results in severely underbonded oxygen, which promotes oxygen loss, whereas Mg2+ remains in Na-2/3[Mg0.28Mn0.72]O-2, which stabilizes oxygen.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据