Electrochemical performance of lithium iron phosphate by solid-state reaction

초록

During the past decades, the research on cathode materias for lithium-ion batteries has focused mainly on lithium transition metal oxides. At present, LiCoO2, LiNiO2, and LiMn2O4 are used commercially as 4V cathode materials in rechargeable lithium-ion batteries. However, the choice of the cathode-active materials must be done not only in relation to battery performance, but also in relation to cost and safety. From many different aspects iron (iron is very plentiful and environmentally benign) is a very attractive metal for use in the field of lithium battery to realize large size batteries for powering electric vehicles or realizing dispersed electrical power sources. Among various active-materials, LiFePO4 with olivine structure is purposed as suitable positive-electrode material for rechargeable lithium-ion batteries because of aspects of high energy density, safety, reliable new materials. In this work, Lithium iron phosphate with olivine structure have been synthesized by solid-state reaction. Lithium iron phosphate was characterized by X-ray diffraction, charge/discharge cycling, scanning electron microscope, cyclic voltammetry, impedance analyzer. Lithium iron phosphate powders synthesized by solid-state reaction show high discharge capacity and excellent cyclability.