Abstract
In this article, we used self-developed process to synthesize LiFePO4 powder. Due to the low conductivity, LiFePO4 was coated with carbon to raise the conductivity. We used sucrose to be the carbon source and get the LiFePO4/C composite. Although the carbon coating can increase the conductivity, it also decreases the energy density. So we have to modify the carbon coating to optimize the performance of our LiFePO4/C powder. As there were some impure phases in the LiFePO4/C powder, we tried to decrease the amount of impure phases by changing the precursors ratio. After solving this problem, we adjusted the amount of sucrose to optimize the LiFePO4/C. We observed the carbon coating by transmission electron microscopy (TEM) and Raman spectroscopy. Finally, we used LiFePO4 synthesized with 15 % sucrose added to proceed the battery charge/discharge cycle test. The battery under test remained at 120mAh/g at 0.2C discharge after 45 cycles.