Microscopy and Spectroscopy of Lithium Nickel Oxide Based Particles Used in High-Power Lithium-Ion Cells

Published

November 1, 2003

Author(s)

D Abraham, R D. Twesten, Mahalingam Balasubramanian, J Kropf, Daniel A. Fischer, James McBreen, I Petrov, K Amine

Abstract

Structural and electronic investigations were conducted on lithium nickel oxide based particles used in positive electrodes of 18650-type high power lithium-ion cells. K-edge X-ray absorption spectroscopy (XAS) revealed trivalent Ni and Co ions in the bulk LiNi0.8Co0.202 powder used to prepare the high-power electrode laminates. Using oxygen K-edge X-ray absorption spectroscopy (XAS), high-resolution electron microscopy (HREM), nano-probe diffraction and electron energy-loss spectroscopy (EELS), we have identified a <5 nm thick modified layer on the surface of the oxide particles, which results from the loss of Ni and Li ordering in the layered R-3m structure. This structural change is accompanied by oxygen loss and a lowering of the Ni- and Co-oxidation states in the surface layer. Growth of this surface layer may contribute to the impedence rise observed during accelerated aging of these lithium-ion cells.

Citation

Journal of the Electrochemical Society

Volume

No. 150

Issue

No. 11

Pub Type

Journals

Keywords

cells, EELS, lithium, NEXAFS, soft x-ray

Citation

Abraham, D. , Twesten, R. , Balasubramanian, M. , Kropf, J. , Fischer, D. , McBreen, J. , Petrov, I. and Amine, K. (2003), Microscopy and Spectroscopy of Lithium Nickel Oxide Based Particles Used in High-Power Lithium-Ion Cells, Journal of the Electrochemical Society (Accessed December 8, 2024)