Changes in Electronic Structure of the Electrochemically Li-ion Deintercalated LiNiO{2} System Investigated by Soft X-ray Absorption Spectroscopy

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Journal of Power Sources

DOI:https://doi.org/10.1016/j.jpowsour.2006.02.013· OSTI ID:959919

Yoon, W; Chung, K; McBreen, J; Fischer, D; Yang, X

The electronic structures of Li1-xNiO2 system after electrochemically deintercalated to various 'x' values have been investigated using soft X-ray absorption spectroscopy (XAS) for oxygen K-edge and Ni LII,III-edge. By comparing the O K-edge XAS spectra of Li1-xNiO2 electrode collected simultaneously by the partial electron yield (PEY) mode and florescence mode (FY), it was found that the surface electronic structure of Li1-xNiO2 electrode is different from the bulk. Therefore, if the PEY mode, which is a surface-sensitive technique, is used alone, the reliability of the results is limited to the surface structures only. Ni LII,III-edge XAS results of Li1-xNiO2 electrode at different charge states, in both the FY and PEY modes, show that Ni2+ ions at the surface are mostly oxidized to Ni3+ ions during Li deintercalation, whereas the process in the bulk is the oxidation of Ni ions from Ni3+ to Ni4+.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959919
• Report Number(s): BNL--82905-2009-JA
• Journal Information: Journal of Power Sources, Journal Name: Journal of Power Sources Journal Issue: 1 Vol. 163; ISSN JPSODZ; ISSN 0378-7753
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
ABSORPTION SPECTROSCOPY
CHARGE STATES
ELECTRODES
ELECTRONIC STRUCTURE
ELECTRONS
OXIDATION
OXYGEN
RELIABILITY
SPECTRA
national synchrotron light source