Thermodynamic and Kinetic Stability of the Solid Solution Phase in Nanocrystalline Li_(x)FePO_4
- Creators
- Tan, H. J.
- Dodd, J. L.
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Fultz, B.
Abstract
Samples of nanostructured Li_(x)FePO_4 with characteristic crystal sizes of 26 nm, and compositions of x = 0.35 and 0.65, were synthesized by ball-milling and chemical delithiation. X-ray powder diffraction showed that the solid solution phase started to form whenever two-phase materials were heated above 200 °C. The solid solution phase of nanocrystalline Li_(0.65)FePO_4 was quick to form above 200 °C but did not unmix at lower temperatures. Unmixing below 200 °C was found after long-time annealing of nanocrystalline Li_(0.35)FePO_4, however, consistent with the equilibrium phase diagram of bulk Li_(x)FePO_4. The stability of the solid solution of nanocrystalline Li_(x)FePO_4 is kinetic in origin, perhaps originating with effects of crystal surfaces.
Additional Information
© 2009 American Chemical Society. Received: July 27, 2009; Revised manuscript received: October 27, 2009. Publication Date (Web): November 6, 2009. We acknowledge help from C. M. Garland with TEM work. The authors thank K. Amine, I. Belharouak, and Argonne National Laboratory for providing LiFePO4 material. This work was supported by General Motors.Additional details
- Eprint ID
- 16907
- DOI
- 10.1021/jp907161z
- Resolver ID
- CaltechAUTHORS:20091208-135031033
- General Motors
- Created
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2009-12-08Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field