Intermittent microwave heating synthesized high performance spherical LiFePO4/C for Li-ion batteries

An intermittent microwave heating method was used to synthesize spherical LiFePO4/C in the presence of glucose as reductive agent and carbon source without the use of the inert gas in the oven processes. The FePO4 was used as iron precursor to reduce the cost and three lithium salts of Li2CO3, LiOH and CH3COOLi were chosen for comparison of the resulting materials. The materials can be alternatively heated by this method at a temperature controllable mode for crystallization and phase transformation and to provide relaxation time for protecting particles growth. The X-ray diffraction and scanning electron microscope measurements confirmed that the LiFePO4/C is olivine structured with the average particle size of 50-100 nm. The spherical LiFePO4/C as cathode material showed better electrochemical performance in terms of the specific capacity and the cycling stability, which might be attributed to the highly crystallized phase, small particle distribution and improved conductivity by carbon connection.