Conductivity improvements to spray-produced LiFePO4 by addition of a carbon source

We present order-of-magnitude conductivity data for carbon-included lithium iron phosphate (LFP) powders lightly pelletised as used as cathodes in Li-ion batteries. The powders were synthesised by a spray pyrolysis method, with a short ameliorating sinter to optimise phase purity. Carbon was introduced into the materials by adding stoichiometric amounts of sucrose into the starting ingredients. We obtained X-ray diffraction patterns and electrical conductivity estimates for carbon contents of between 0 and 31 wt.%. The resultant conductivities spanned almost seven orders of magnitude. (C) 2004 Elsevier B.V All rights reserved.