Electrochemical properties of LiFePO4-multiwalled carbon nanotubes composite cathode materials for lithium polymer battery

LiFePO4-multiwalled carbon nanotubes (MWCNTs) composites were prepared by a hydrothermal method followed by ball-milling and heat treating. Cyclic voltammetry, ac impedance and galvanostatic charge/ discharge testing results indicate that LiFePO4-MWCNTs composite exhibits higher discharge capacity and rate capability than pure LiFePO4 at high-rate at room temperature. It is demonstrated that the added MWCNTs not only increase the electronic conductivity and lithium-ion diffusion coefficient but also decrease crystallite size and charge transfer resistance of LiFePO4-MWCNTs composite. (C) 2008 Elsevier B.V. All rights reserved.