Synthesis of LiFePO<sub>4</sub>/C Nanocomposite and its Electrochemical Properties

Abstract

LiFePO4/C nanocomposite was synthesized by the polyol process without any further heating as a post step and its properties were compared to LiFePO4with no carbon. The X-ray diffraction patterns of all samples were indexed on the basis of the orthorhombic olivine-type structure. The field emission-SEM and TEM images of the nanocomposite showed agglomerated larger particles with rod type mixed with carbon nanoparticles. The initial discharge capacity of LiFePO4/C nanocomposite showed 166 mAh/g at a current density of 0.1 mA/cm2in the voltage range of 2.5-4.2 V without capacity fading during the 20 cycles. Furthermore, the nanocomposite appeared more enhanced high rate performance, compared with the result of LiFePO4with no carbon, due to the existence of conductive agents such as carbon which suppresses particle growth and exhibits improved electronic conductivity and lithium ion diffusivity, simultaneously.