Preparation of LiFePO4 Using Chitosan and its Cathodic Properties for Rechargeable Li-ion Batteries

The LiFePO4 powder was synthesized by using the solid state reaction method with Fe(C2O4)․2H2O, (NH4)2HPO4, Li2CO3, and chitosan as a carbon precursor material for a cathode of a lithium-ion battery. The chitosan added LiFePO4 powder was calcined at 350 oC for 5 hours and then 800 oC for 12 hours for the calcination. Then we calcined again at 800 oC for 12 hours. We characterized the synthesized compounds via the crystallinity, the valence states of iron ions, and their shapes using TGA, XRD, SEM, TEM, and XPS. We found that the synthesized powders were carbon-coated using TEM images and the iron ion is substituted from 3+ to 2+ through XPS measurements. We observed voltage characteristics and initial charge-discharge characteristics according to the C rate in LiFePO4 batteries. The obtained initial specific capacity of the chitosan added LiFePO4 powder is 110 mAh/g, which is much larger than that of LiFePO4 only powder. KCI Citation Count: 12