Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-25T15:23:26.967Z Has data issue: false hasContentIssue false

Iron Phosphates as Cathodes of Lithium-Ion Batteries

Published online by Cambridge University Press:  26 February 2011

Shijun Wang
Affiliation:
[email protected], State University of New York at Binghamton, Materials Science, 4400 Vestal Pkwy E, P.O. Box 6000, Binghamton, NY, 13902, United States
M. Stanley Whittingham
Affiliation:
[email protected], State University of New York at Binghamton, Materials Science, Binghamton, NY, 13902, United States
Get access

Abstract

This study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.

Type
Research Article
Copyright
Copyright © Materials Research Society 2007

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. Yang, S., Zavalij, P. Y. and Whittingham, M. S., Electrochem. Commun., 3, 505 (2001).Google Scholar
2. Arnold, G., Garche, J., Hemmer, R., Strobele, S., Vogler, C., and Wohlfahrt-Mehrens, M., Journal of Power Sources, 119–121, 247 (2003).Google Scholar
3. Wang, G. X., Bewlay, S. L., Konstantinov, K., Liu, H. K., Dou, S. X., and Ahn, J. H., Electrochimica Acta, 50, 443 (2004).Google Scholar
4. Yang, S., Song, Y., Zavalij, P. Y., and Whittingham, M. S., Electrochem. Commun., 4, 239 (2002).Google Scholar
5. Song, Y., Zavalij, P. Y., Chernova, N. A., and Whittingham, M. S., Chem. Mater., 17, 1339 (2005).Google Scholar
6. Gheith, M. A., Am. Mineral., 38, 612 (1953).Google Scholar
7. Schmid-Beurmann, P., J. Solid State Chem., 153, 237 (2000).Google Scholar
8. Toby, B. H., J. Appl. Cryst., 34, 210 (2001).Google Scholar
9. Chen, J., Wang, S. and Whittingham, M. S., J. Power Sources, IMLB meeting (submitted).Google Scholar