Muhamad Faisal - Academia.edu (original) (raw)
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Papers by Muhamad Faisal
Pure lithium iron phosphate (LiFePO 4 ) and carbon-coated LiFePO 4 (C-LiFePO 4 ) cathode material... more Pure lithium iron phosphate (LiFePO 4 ) and carbon-coated LiFePO 4 (C-LiFePO 4 ) 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 LiFePO 4 particles. Ex situ Raman spectrum of C-LiFePO 4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO 4 and C-LiFePO 4 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 LiFePO 4 where as in case of C-LiFePO 4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO 4 was 69% after 25 cycles where as that of C-LiFePO 4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.
Pure lithium iron phosphate (LiFePO 4 ) and carbon-coated LiFePO 4 (C-LiFePO 4 ) cathode material... more Pure lithium iron phosphate (LiFePO 4 ) and carbon-coated LiFePO 4 (C-LiFePO 4 ) 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 LiFePO 4 particles. Ex situ Raman spectrum of C-LiFePO 4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO 4 and C-LiFePO 4 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 LiFePO 4 where as in case of C-LiFePO 4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO 4 was 69% after 25 cycles where as that of C-LiFePO 4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.