Electrochemical and morphologic studies of spherical LiFePO4/nanostructured LiFePO4 fibers composite by solid-state blending

The key issue with lithium iron phosphate (LiFePO4) is poor ionic conductivity. Nanostructured electrodes could improve the rate capability and insertion kinetics. Although cathode or anode materials with large surface area are expected to decrease the solid-state diffusion path length, the problem of tap density remains. In this work, spherical LiFePO4 powder and LiFePO4 nanofibers cathode materials are blended to improve their energy density and rate capability by high tap density and the network effect of nanofibers. The composite cathode is made by solid-state blending the spherical LiFePO4/C (90 wt%) powders with LiFePO4/C nanofibers (10 wt%). Additionally, we investigate another type composite by hot-press treatment for the binding between the two components. A systematic structural and electrochemical characterization of the LiFePO4 series is carried out by X-ray diffraction, field emission scanning electron microscopy, and electrochemical measurements. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.