Characterization of LiM[sub x]Fe[sub 1−x]PO[sub 4] (M=Mg, Zr, Ti) Cathode Materials Prepared by the Sol-Gel Method

A series of phosphates were synthesized via a sol-gel method. Transmission electron microscopy observations show that 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 particles, which substantially increases the electronic conductivity of electrodes. The doped powders are phase pure. Near full capacity (170 mAh/g) was achieved at the C/8 rate at room temperature for electrodes. The doped electrodes demonstrated better electrochemical performance than that of undoped at high rate.