Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 1, 2006 | public
Journal Article

Crystal structure studies of thermally aged LiCoO_2 and LiMn_2O_4 cathodes

Abstract

LiCoO_2 and LiMn_2O_4 cathodes were studied by X-ray diffractometry (XRD) and electron diffraction after ageing in the charged state at elevated temperature. Some cathodes were stopped at different times during ageing and XRD measurements were taken to monitor changes in the crystal structure over ageing time. The results indicate that Li-ions intercalate into the cathodes lattice during ageing thus decreasing the available discharge capacity. Analysis of electron diffraction patterns of LiCoO_2 and LiMn_2O_4 retrieved from the cathodes after ageing shows that irreversible crystallographic transformations have taken place in both electrodes. Dark field imaging illustrates that LiCoO_2 forms a layer of spinel phase on its surface. In LiMn_2O_4 a tetragonal distorted spinel is observed when the cathode has been in the 3 V regime for considerable length of time.

Additional Information

© 2006 Elsevier Ltd. Received 20 October 2005; received in revised form 5 February 2006; accepted 24 February 2006 Available online 22 May 2006. This work has been supported through grants HR0011-04-1-0029 from DARPA, DMR-0315579 from NSF and by DOE through Basic Energy Sciences Grant DE-FG03-00ER15035. The authors thank ENAX Co. Japan for providing the cathodes.

Additional details

Created:
August 22, 2023
Modified:
October 23, 2023