New approach for synthesis of carbon-mixed LiFePO4 cathode materials

For the first time, carbon-mixed LiFePO4 (LFP) cathode materials have been prepared by spray solution technology. Nominal addition of 15 or 20 wt.% C was used in order to simulate the industrial practice for preparation of electrode materials. The prepared powders consist of a single LiFePO4 phase: small crystallites with a highly developed surface area, beneficial for the surface electrochemical processes limited by the low Li diffusion. The combination of spray technology and carbon addition increased the specific surface area above 20 m(2)/g at a relatively high sintering temperature (700 degreesC). The initial discharge capacity was up to 140 mAh/g compared to 125 mAh/g for conventionally prepared (using a solid state reaction) LiFePO4 electrode materials. (C) 2004 Elsevier Ltd. All rights reserved.