Investigation of the Charge Compensation Mechanism on the Electrochemically Li-Ion Deintercalated Li1-xCo1/3Ni1/3Mn1/3O2 Electrode System by Combination of Soft and Hard X-ray Absorption Spectroscopy
In situ hard X-ray absorption spectroscopy (XAS) at metal K-edges and soft XAS at O K-edge and metal L-edges have been carried out during the first charging process for the layered Li{sub 1-x}Co{sub 1/3}Ni{sub 1/3}Mn{sub 1/3}O{sub 2} cathode material. The metal K-edge XANES results show that the major charge compensation at the metal site during Li-ion deintercalation is achieved by the oxidation of Ni{sup 2+} ions, while the manganese ions and the cobalt ions remain mostly unchanged in the Mn{sup 4+} and Co{sup 3+} state. These conclusions are in good agreement with the results of the metal K-edge EXAFS data. Metal L-edge XAS results at different charge states in both the FY and PEY modes show that, unlike Mn and Co ions, Ni ions at the surface are oxidized to Ni{sup 3+} during charge, whereas Ni ions in the bulk are further oxidized to Ni{sup 4+} during charge. From the observation of O K-edge XAS results, we can conclude that a large portion of the charge compensation during Li-ion deintercalation is achieved in the oxygen site. By comparison to our earlier results on the Li{sub 1-x}Ni{sub 0.5}Mn{sub 0.5}O{sub 2} system, we attribute the active participation of oxygen in the redox process in Li{sub 1-x}Co{sub 1/3}Ni{sub 1/3}Mn{sub 1/3}O{sub 2} to be related to the presence of Co in this system.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 913819
- Report Number(s):
- BNL-78387-2007-JA; JACSAT; TRN: US0801384
- Journal Information:
- J. Am. Chem. Soc., Vol. 127, Issue 49; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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