Role of oxygen holes in LixCoO2 revealed by soft X-ray spectroscopy

Takashi Mizokawa, Y. Wakisaka, T. Sudayama, C. Iwai, K. Miyoshi, J. Takeuchi, H. Wadati, D. G. Hawthorn, T. Z. Regier, G. A. Sawatzky

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Abstract

The fundamental electronic structure of the widely used battery material LixCoO2 still remains a mystery. Soft x-ray absorption spectroscopy of LixCoO2 reveals that holes with strong O 2p character play an essential role in the electronic conductivity of the Co3+/Co4+ mixed valence CoO2 layer. The oxygen holes are bound to the Co4+ sites and the Li-ion vacancy, suggesting that the Li-ion flow can be stabilized by oxygen hole back flow. Such an oxygen hole state of LixCoO2 is unique among the various oxide-based battery materials and is one of the key ingredients to improving their electronic and Li-ion conductivities.

Original languageEnglish
Article number056404
JournalPhysical Review Letters
Volume111
Issue number5
DOIs
Publication statusPublished - 2013 Aug 2
Externally publishedYes

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Mizokawa, T., Wakisaka, Y., Sudayama, T., Iwai, C., Miyoshi, K., Takeuchi, J., Wadati, H., Hawthorn, D. G., Regier, T. Z., & Sawatzky, G. A. (2013). Role of oxygen holes in LixCoO2 revealed by soft X-ray spectroscopy. Physical Review Letters, 111(5), [056404]. https://doi.org/10.1103/PhysRevLett.111.056404