Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-02T23:04:37.784Z Has data issue: false hasContentIssue false

Decomposition Kinetics of Lithium Amide and Its Implications for Hydrogen Storage

Published online by Cambridge University Press:  01 February 2011

Frederick E. Pinkerton*
Affiliation:
Materials and Processes Laboratory, MC 480–106–224, General Motors Research and Development Center, Warren, MI 48090–9055
Get access

Abstract

Kinetics of the lithium amide (LiNH2) decomposition reaction 2 LiNH2 → Li2NH + NH3 were determined using thermogravimetric analysis (TGA). LiNH2 is a primary component of the hydrided state of Li3N- and Li2NH-based storage materials. Its decomposition by ammonia release, and the resulting degradation of hydrogen storage capacity, has important implications for the durability of Li-N-H storage systems. Fine powders of LiNH2 were prepared by ball milling for 20 min. Kinetic parameters were extracted from a set of TGA weight loss curves taken at different heating rates between 1 and 20°C/min, and the activation energy Ea was determined to be 124 kJ/mole. Although decomposition occurs slowly below 300°C, isothermal TGA measurements on Li3N demonstrate that its cumulative effect is large in real Li-N-H systems, where LiNH2-containing hydrided material is held at elevated temperature under dynamic gas flow.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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. Pinkerton, F. E. and Wicke, B. G., The Industrial Physicist 10, 20 (February/March 2004).Google Scholar
2. Chen, P., Xiong, Z., Luo, J., Lin, J., and Tan, K. L., Nature 420, 302 (2002).Google Scholar
3. Meisner, G. P., Pinkerton, F. E., Meyer, M. S., and Balogh, M. P. in Proceedings of the International Symposium on Metal-Hydrogen Systems 2004, Cracow, Poland, 5 Sep 2004; J. Alloys Compounds, in press.Google Scholar
4. Ichikawa, T., Isobe, S., Hanada, N., and Fujii, H., J. Alloys Comp. 365, 271 (2004).Google Scholar
5. Juza, R. and Opp, K., Z. anorg. allg. Chem. 266, 325 (1951).Google Scholar
6. Pinkerton, F. E., Meyer, M. S., Tibbetts, G. G., and Chahine, R. in Proc. 11th Canadian Hydrogen Conference, edited by McLean, G. F. (Canadian Hydrogen Association, Canada, 2001) pp. 633642.Google Scholar
7. Irrelevant regions where no weight changes occur have been omitted for simplicity.Google Scholar
8. Dehydriding was performed under flowing He gas at 130 kPa. The TGA gas flow was switched back to H2 gas for rehydriding.Google Scholar
9. Ozawa, T., Bull. Chem. Soc. Jpn. 38, 1881 (1965).Google Scholar
10. Flynn, J. H. and Wall, L. A., Polym. Lett. 4, 323 (1966).Google Scholar
11. Doyle, C. D., J. Appl. Polym. Sci. 5, 285 (1961).Google Scholar
12. Zsako, J. and Zsako, J. Jr, Therm. Anal. 19, 333 (1980).Google Scholar