Abstract:LiFePO₄/C composites were synthesized by a molten salt (MS) method using the mixture of LiCl, LiOH and NaCl. The prepared LiFePO₄/C composites are characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM) and charge−discharge test. XRD patterns indicate that LiFePO₄ prepared in the temperature range of 550−700 ℃ crystallizes well in an olivine-type structure. Through FESEM images, the sphere-like and homogeneous particles of 0.2 μm can be observed. The charge−discharge test shows that the materials prepared at 600 ℃ for 12 h have good electrochemical performance. At the rates of 0.2C (34 mA/g) and 0.5C, the discharge capacities are 144.6 and 122.3 mA∙h/g, respectively, together with good cycle performances.

Key words: lithium iron phosphate; molten salt method; cathode material; Li-ion batteries