Electrochemical performance of Sol-Gel synthesized LiFePO{sub 4} in lithium batteries
LiFePO{sub 4}, Li{sub 0.98}Mg{sub 0.01}FePO{sub 4}, and Li{sub 0.96}Ti{sub 0.01}FePO{sub 4} were synthesized via a sol-gel method, using a variety of processing conditions. For comparison, LiFePO{sub 4} was also synthesized from iron acetate by a solid state method. The electrochemical performance of these materials in lithium cells was evaluated and correlated to mean primary particle size and residual carbon structure in the LiFePO{sub 4} samples, as determined by Raman microprobe spectroscopy. For materials with mean agglomerate sizes below 20 {micro}m, an association between structure and crystallinity of the residual carbon and improved utilization was observed. Addition of small amounts of organic compounds or polymers during processing results in carbon coatings with higher graphitization ratios and better electronic properties on the LiFePO{sub 4} samples and improves cell performance in some cases, even though total carbon contents remain very low (<2%). In contrast, no performance enhancement was seen for samples doped with Mg or Ti. These results suggest that it should be possible to design high power LiFePO{sub 4} electrodes without unduly compromising energy density by optimizing the carbon coating on the particles.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Assistant Secretary for Energy Efficiency and Renewable Energy. Office of the FreedomCAR and Vehicle Technologies Program; Department of Chinese Education (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 835152
- Report Number(s):
- LBNL-53002; R&D Project: 500301; TRN: US200435%%82
- Journal Information:
- Journal of the Electrochemical Society, Vol. 151, Issue 8; Other Information: Submitted to Journal of the Electrochemical Society, Volume 151, No.8; Journal Publication Date: 2004; PBD: 16 Jun 2003
- Country of Publication:
- United States
- Language:
- English
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