Synthesis and Electrochemical Performance of LiCoPO4 by Sol-Gel Method

High potential cathode material LiCoPO4 was synthesized by sal-gel method. The effects of different sintering conditions on the crystal structure, surface morphology and electrochemical performance of LiCoPO4 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and charge-discharge tests. The results show that the sample synthesized at 650 00 for 12 h has a good crystalline orthorhombic olivine-type structure and a uniform particle distribution (0.2-0.4 mu m), which delivers the best electrochemical performance. The discharge capacity of the sample at 1C rate can reach 122.7 mAh.g(-1). Moreover, from the charge and discharge profiles, two charge/discharge plateaus are presented and they become more obvious with the increase of charge/discharge rate. This phenomenon can be interpreted by considering the two-step extraction/insertion behavior of Li+ in LiCoPO4.