ABSTRACT LiFePO4 materials synthesized using FePO4(H2O)2 and Li2CO3 blend were optimized in view of their use as positive electrodes in Li-ion batteries for hybrid electric vehicles. A strict control of the structural properties was made by the combination of X-ray diffraction, FT-infrared spectroscopy and magnetometry. The impact of the ferromagnetic clus-ters (γ-Fe2O3 or Fe2P) on the electrochemical response was examined. The electrochemical performances of the opti-mized LiFePO4 powders investigated at 60℃ are excellent in terms of capacity retention (153 mAh·g-1 at 2C) as well as in terms of cycling life. No iron dissolution was observed after 200 charge-discharge cycles at 60℃ for cells containing Li foil, Li4Ti5O12, or graphite as negative electrodes.
Cite this paper
C. M. Julien, K. Zaghib, A. Mauger and H. Groult, "Enhanced Electrochemical Properties of LiFePO4 as Positive Electrode of Li-Ion Batteries for HEV Application," Advances in Chemical Engineering and Science, Vol. 2 No. 3, 2012, pp. 321-329. doi: 10.4236/aces.2012.23037.
 A. K. Padhi, K. S. Nanjundaswamy and J. B. Goodenough, “Phospho-Olivines as Positive-Electrode Materials for Rechargeable Lithium Batteries,” Journal of the Electrochemical Society, Vol. 144, No. 4, 1997, pp. 1188-1194. doi:10.1149/1.1837571
 N. Ravet, Y. Chouinard, J. F. Magnan, S. Besner, M. Gauthier and M. Armand, “Electroactivity of Natural and Synthetic Triphylite,” Journal of Power Sources, Vol. 97-98, 2001, pp. 503-507.
 N. Ravet, A. Abouimrane and M. Armand, “From Our Readers: On the Electronic Conductivity of Phospho-Olivines as Lithium Storage Electrodes,” Nature Materials, Vol. 2, 2003, pp. 702-703. doi:10.1038/nmat1009b
 N. Ravet, S. Besner, M. Simoneau, A. Vallee, M. Armand and J. F. Magnan, “Electrode materials with high surface conductivity,” US Patent No. 6962666, 2005.
 Y. Hu, M. M. Doeff, R. Kostecki and R. Finones, “Electrochemical Performance of Sol-Gel Synthesized LiFePO4 in Lithium Batteries,” Journal of the Electrochemical Society, Vol. 151, No. 8, 2004, pp. A1279-A1285.
 S. L. Bewlay, K. Konstantinov, G. X. Wang, S. X. Dou and H. K. Liu, “Conductivity Improvements to Spray-Produced LiFePO4 by Addition of a Carbon Source,” Materials Letters, Vol. 58, No. 11, 2004, pp. 1788-1791.
 K. Zaghib, V. Battaglia, P. Charest, V. Srinivasan, A. Guerfi and R. Kostecki, Extended Abstract of the International Battery Association & Hawaii Battery Conference, Wailoloa, 9-12 January 2006.
 A. A. Salah, P. Jozwiak, J. Garbarczyk, F. Gendron, A. Mauger and C. M. Julien, “FTIR Features of Lithium Iron Phosphates Used as Positive Electrodes in Rechargeable Lithium Batteries,” 207th ESC Meeting, Quebec City, 15-20 May 2005.
 M. M. Doeff, Y. Hu, F. McLarnon and R. Kostecki, “Effect of Surface Carbon Structure on the Electrochemical Performance of LiFePO4,” Electrochemical and Solid-State Letters, Vol. 6, No. 10, 2003, pp. A207-A209.
 A. Ait-Salah, A. Mauger, F. Gendron and C. M. Julien, “Magnetic Studies of the Carbothermal Effect on LiFePO4,” Physica Status Solidi (a), Vol. 203, No. 1, 2006, pp. R1-R3.
 A. Ait-Salah, A. Mauger, C. M. Julien and F. Gendron, “Nano-Sized Impurity Phases in Relation to the Mode of Preparation of LiFePO4,” Materials Science and Engineering: B, Vol. 129, No. 1-3, 2006, pp. 232-244.
 A. Ait-Salah, A. Mauger, K. Zaghib, J. B. Goodenough, N. Ravet, M. Gauthier, F. Gendron and C. M. Julien, “Reduction Fe3+ of Impurities in LiFePO4 from Pyrolysis of Organic Precursor Used for Carbon Deposition,” Journal of the Electrochemical Society, Vol. 153, No. 9, 2006, pp. A1692-A1701. doi:10.1149/1.2213527
 A. Yamada, S. C. Chung and K. Hinokuma, “Optimized LiFePO4 for Lithium Battery Cathodes,” Journal of the Electrochemical Society, Vol. 148, No. 3, 2001, pp. A224-A229. doi:10.1149/1.1348257
 K. Zaghib, J. Shim, A. Guerfi, P. Charest and K. A. Striebel, “Effect of Carbon Source as Additives in LiFePO4 as Positive Electrode for Lithium-Ion Batteries,” Electrochemical and Solid-State Letters, Vol. 8, No. 4, 2005, pp. A207-A210. doi:10.1149/1.1865652
 K. Zaghib and M. Armand, “Electrode Covered with a Film Obtained from an Aqueous Solution Containing a Water Soluble Inder, Manufacturing Process and Usesthereof,” Canadian Patent No. CA 2411695, 2002.
 K. Striebel, J. Shim, V. Srinivasan and J. Newman, “Comparison of LiFePO4 from Different Sources,” Journal of the Electrochemical Society, Vol. 152, No. 4, 2005, pp. A664-A670. doi:10.1149/1.1862477
 A. Ait-Salah, P. Jozwiak, J. Garbarczyk, K. Benkhouja, K. Zaghib, F. Gendron and C. M. Julien, “Local Structure and Redox Energies of Lithium Phosphates with Olivine- and Nasicon-Like Structures,” Journal of Power Sources, Vol. 140, No. 2, 2005, pp. 370-375.
 R. Bacewicz, P. Woroniecki and J. Garbarczyk, “Raman Scattering in AgI-Ag4O-P4O4 Glasses,” Physics and Chemistry of Glasses, Vol. 40, No. 3, 1999, pp. 175-176.
 A. Adamczyk, M. Handke and W. Mozgawa, “FTIR Studies of BPO42SiO2, BPO4SiO2 and 2BPO4SiO2 Joints in Amorphous and Crystalline Forms,” Journal of Molecular Structure, Vol. 511-512, 1999, pp. 141-144. doi:10.1016/S0022-2860(99)00152-0
 R. P. Santoro and R. E. Newnham, “Antiferromagnetism in LiFePO4,” Acta Crystallographica, Vol. 22, 1967, pp. 344-347. doi:10.1107/S0365110X67000672
 G. Arnold, J. Garche, R. Hemmer, S. Strobele, C. Vogler and M. Wohlfahrt-Mehrens, “Fine-Particle Lithium Iron Phosphate LiFePO4 Synthesized by a New Low-Cost Aqueous Precipitation Technique,” Journal of Power Sources, Vol. 119-121, 2003, pp. 247-251.
 C. M. Julien, K. Zaghib, A. Mauger, M. Massot, A. Ait-Salah, M. Selmane and F. Gendron, “Characterization of the Carbon Coating onto LiFePO4 Particles Used in Lithium Batteries,” Journal of Applied Physics, Vol. 100, No. 6, 2006, Article ID: 063511. doi:10.1063/1.2337556
 S. H. Yu, C. K. Park, H. Jang, C. B. Shin and W. II Cho, “Prediction of Lithium Diffusion Coefficient and Rate Performance by Using the Discharge Curves of LiFePO4 Materials,” Bulletin of the Korean Chemical Society, Vol. 32, No. 3, 2011, pp. 852-856.
 K. Zaghib, P. Charest, M. Dontigny, A. Guerfi, M. Petitclerc and M. Duchesne, “Olivines: 10 Years R & D at Hydro-Québec in Li-Ion Batteries,” Rechargeable Lithium and Lithium Ion Batteries Battery/Energy Technology, Washington DC, 7-12 October 2007, Abstract No. 637.