Abstract:
A series of LiMxFe1-xPO4 (M = Mg,Zr,Ti) phosphates were synthesized via a sol-gel method. Transmission electron microscopy observations show that LiMxFe1-xPO4 particles consist of nanosize crystals, ranging from 40 to 150 nm. High-resolution TEM analysis reveals that a layer of amorphous carbon was coated on the surface of the LiMxFe1-xPO4 particles, which substantially increases the electronic conductivity of LiMxFe1-xPO4 electrodes. The doped LiMxFe1-xPO4 powders are phase pure. Near full capacity (170 mAh/g) was achieved at the C/8 rate at room temperature for LiMxFe1-xPO4 electrodes. The doped LiMxFe1-xPO4 electrodes demonstrated better electrochemical performance than that of undoped LiFePO4 at high rate.