P2-Na0.6[Cr0.6Ti0.4]O2 cation-disordered electrode for high-rate symmetric rechargeable sodium-ion batteries
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Date
2015-04-24
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature
Abstract
Most P2-type layered oxides exhibit Na+/vacancy-ordered superstructures because of strong Na+–Na+ interaction in the alkali metal layer and charge ordering in the transition metal layer. These superstructures evidenced by voltage plateaus in the electrochemical curves limit the Na+ ion transport kinetics and cycle performance in rechargeable batteries. Here we show that such Na+/vacancy ordering can be avoided by choosing the transition metal ions with similar ionic radii and different redox potentials, for example, Cr3+ and Ti4+. The designed P2-Na0.6[Cr0.6Ti0.4]O2 is completely Na+/vacancy-disordered at any sodium content and displays excellent rate capability and long cycle life. A symmetric sodium-ion battery using the same P2-Na0.6[Cr0.6Ti0.4]O2 electrode delivers 75% of the initial capacity at 12C rate. Our contribution demonstrates that the approach of preventing Na+/vacancy ordering by breaking charge ordering in the transition metal layer opens a simple way to design disordered electrode materials with high power density and long cycle life. Copyright © 2015, The Author(s)
Description
Keywords
Radioisotope batteries, Transition elements, Alkali metals, Electrodes, Cathodes, Electrochemical cells, Oxides
Citation
Wang, Y., Xiao, R., Hu, Y., Avdeev, M., & Chen, L.(2015). P2-Na0.6[Cr0.6Ti0.4]O2 cation-disordered electrode for high-rate symmetric rechargeable sodium-ion batteries. Nature Communications 6, 6954. doi:10.1038/ncomms7954