Abstract
Li-rich and stoichiometric Li 1Mn 1.5Ni 0.5O 4 (LMNO) cathode films have been successfully prepared by magnetron sputtering. Sputtering from a Li stoichiometric target yields Li-rich films composed of spinel, layered and monoclinic phases. Films obtained from a Li deficient target are mostly made of a spinel phase and little layered material. The resulting cathode thin films have good capacity retention and very high rate capability. The reaction mechanism has been investigated by XRD and HRTEM and evidences the reversible formation of a spinel phase, as is generally found for the powder samples. The film geometry enables us to understand the effect of coatings (ZnO or LiPON). Coating high voltage cathodes reduces the coulombic losses, but at the price of rate performance. Nonetheless, these coated sputtered electrode thin films offer a higher rate capability than other LMNO thin films obtained by other physical vapor deposition techniques.
| Original language | English |
|---|---|
| Pages (from-to) | 108-118 |
| Number of pages | 11 |
| Journal | Journal of Power Sources |
| Volume | 211 |
| DOIs | |
| State | Published - Aug 1 2012 |
Funding
This research was supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. Microscopy research was also supported by ORNL SHaRE user facility, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Appendix A
Keywords
- Coatings
- High voltage spinel cathodes
- Layered-spinel composite structure
- Magnetron sputtering
- Thin films
