Cathode Materials Based on Lithium Iron Phosphate/PEDOT Composites for Lithium-Ion Batteries

Abstract

Composites based on LiFePO4/C and poly(3,4-ethylenedioxythiophene) (LiFePO4/C/PEDOT) have been prepared via in situ oxidative EDOT polymerization or mechanical mixing of LiFePO4/C with presynthesized PEDOT particles, including those prepared in the presence of different surfactants (Triton X-100 and cetyltrimethylammonium bromide). The resultant materials have been characterized by X-ray diffraction, scanning electron microscopy, CNHS analysis, and IR spectroscopy. At high current densities, the best electrochemical performance has been demonstrated by the composite prepared by mechanical mixing of LiFePO4/C with a PEDOT suspension in acetonitrile (70 mAh/g at a current density of 1600 mA/g). Further increase in the discharge capacity of the LiFePO4/C/PEDOT composites at high current densities has been ensured by precoating LiFePO4/C particles with the Triton X-100 surfactant (81 mAh/g at 1600 mA/g).