%0 Journal Article
%T Structural and Electrochemical Characterization of Pure  and Nanocomposite C- Cathodes for Lithium Ion Rechargeable Batteries
%A Arun Kumar
%A R. Thomas
%A N. K. Karan
%A J. J. Saavedra-Arias
%A M. K. Singh
%A S. B. Majumder
%A M. S. Tomar
%A R. S. Katiyar
%J Journal of Nanotechnology
%D 2009
%I Hindawi Publishing Corporation
%R 10.1155/2009/176517
%X Pure lithium iron phosphate (LiFePO4) and carbon-coated LiFePO4 (C-LiFePO4) cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO4 and C-LiFePO4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO4 where as in case of C-LiFePO4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO4 was 69% after 25 cycles where as that of C-LiFePO4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.
%U http://www.hindawi.com/journals/jnt/2009/176517/