Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-23T01:28:27.952Z Has data issue: false hasContentIssue false

Ambient temperature synthesis of polycrystalline thin films of lithium cobalt oxide with controlled crystallites orientations

Published online by Cambridge University Press:  10 February 2011

R.B. Goldner
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
P. Zerigian
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
T.Y. Liu
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
N. Clay
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
F. Vereda
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
T.E. Haas
Affiliation:
Tufts University Electro-Optics Technology Center, 4 Colby St., Medford, MA 02155
Get access

Abstract

Polycrystalline thin films of lithium cobalt oxide (nominally LiCo02) have been deposited by a process which we have named, ion beam directed assembly (IBDA). It is similar to ion assisted deposition (IAD) or ion beam assisted deposition (IBAD), but the major difference is that in IBDA the ion beam directs, via the vector momenta of the ions, rather than merely assists, the growth. Hence, we also term the process directed assembly to distinguish it from self assembly. Also, in directed assembly the ions may or may not become an integral part of the film's composition.

In this paper we wish to show that the IBDA process may be capable of controlling microstructure, e.g., in the case of polycrystalline films, control the orientations of the crystallites. For LiCoO2 we have observed this in two ways - by X-ray analysis, and electrochemically, by lithium diffusivity measurements. In particular, we have observed increased lithium diffusivities (≥ 10−8 cm 2/s) in IBDA deposited films as compared to that found for rf sputter deposited films (z 10−10 cm2/s). In addition, the coulometric titration characteristics of an IBDA deposited Lil−yCoO2 are very similar to those of sputtered deposited films (for lithium extraction/insertion, y ≤0.5, and for quasi-equilibrium voltages up to 4.2 volts).

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Bates, J.B. et al. , Solid State Ionics 70/71,619 (1994); and B. Wang, et al., J.Electrochem.Soc. 10, 3203 (1996).Google Scholar
2. Julien, C. and Nazri, C.A., Solid State Batteries: Materials Design and Optimization, Kluwer Academic Publishers, Boston (1994).Google Scholar
3. Goldner, R.B. et al. , Proc. Electrochem.Soc., PV 95–22, 173 (1996).Google Scholar
4. See., e.g., Cuomo, J.J. et al. , Handbook of Ion Beam Processing Technology Noyes Publications, Park Ridge, NJ (1989); and R.J. Culbertson, Materials Synthesis and Processing Using Ion Beams Materials Research Society Symposium Proceedings, vol. 316 (1993). (Note that crystal orientation effects in films deposited by use of an assisting ion beam were reported in these two references.)Google Scholar
5. The alumina substrates were donated by Lucent Technologies, thanks to D.Krause.Google Scholar
6. Goldner, R.B. et al. , J.Electrochem.Soc. 143, L129 (1996).Google Scholar
7. Warren, B.E., “X-Ray Diffraction,” p. 252, Dover Publications, Inc., NY (1990)].Google Scholar
8. Thomas, M.G.S.R. et al. , Solid State Ionics 17, 13 (1985).Google Scholar
9. Gummow, R.J. et al. , Mat. Res. Bull. 28, 235 (1993).Google Scholar