Versatile Synthesis of Carbon-Rich LiFePO_4 Enhancing Its Electrochemical Properties

摘要

LiFePO_4/C composites were prepared from thermal decomposition of Fe(II) organophosphonates Fe[(RPO_3)(H_2O)] (R = methyl or phenyl group) in the presence of Li_2CO_3 at high temperature and under inert atmosphere. The compounds were characterized by chemical analysis, thermogravimetric analysis and differential scanning colorimetry, X-ray powder diffraction, and scanning electron microscopy. Electrodes were fabricated for the electrochemical characterization. The cathode material obtained from Fe[C_6H_5PO_3(H_2O)] showed a specific energy evaluated at C/10 rate of about 550 Wh kg~(-1). The specific power calculated at 30C rate in excess at 14,000 W kg~(-1), while the specific energy was about 28 percent of the theoretical one. No capacity fading was observed upon cycling.