Synthesis,Characterization and Properties of LiFePO_4/C Cathode Material

摘要

Lithium iron phosphate coated with carbon （LiFePO4/C） was synthesized by improved solid-state reaction using comparatively lower temperature and fewer sintering time. The carbon came from citric acid, which acted as a new carbon source. It was characterized by thermogravimetry and differential thermal analysis （TG/DTA）, X ray diffractometer （XRD）, Element Analysis （EA） and Scanning electron microscope （SEM）. We also studied the electrochemical properties of the material. The first discharge capacity of the LiFePO4/C is 121 mAh5g-1 at 10 mA5g-1 at room temperature. When the current density increased to 100 mA5g-1, the first discharge capacity decreased to 110 mAh5g-1 and retained 95% of the initial capacity after 100 cycles. The LiFePO4/C obtained shows a good electrochemical capacity and cycle ability at a large current density.