Study on the Preparation of Lifepo4 by Hydrothermal Method

Abstract

A simple hydrothermal process combined with carbon coating is attempted to prepare nano particle LiFePO4 cathode materials for Li-ion batteries. A carbon coating process with glucose is used to make LiFePO4/C composites. The structure, morphology and electrochemical properties of the materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and constant current charge/discharge. The X-ray diffraction pattern indicates that the pure phase LiFePO4 material could be prepared at different reaction temperatures, and the pure phase LiFePO4 material could not be prepared with the reaction time of 6 h. SEM test shows that the dispersion of LiFePO4 particles become better with the increase of reaction temperatures and the morphology is more regular with the increase of reaction temperature. But when the reaction temperature increases to 200 °C, LiFePO4 particles reaggregate severely. As the reaction time increases, the particles of the sample gradually grow. The electrochemical performance indicates that the sample synthesized at 180 °C for 10 h has the highest specific capacity of 139.5 mAh•g-1 at 0.1 C. This study shows that proposed process can be a potential promising way to prepare high performance LiFePO4 cathode materials.