Air exposure effect on LiFePO4

The impact of ambient air exposure on LiFePO4/C nanocomposites has been investigated. A pristine sample was prepared without any exposure to ambient air through the whole process of synthesis and characterization and compared to the exposed samples. A small amount of lithium deintercalates from the olivine structure during exposure, a majority of which can be electrochemically reintercalated. This phenomenon changes the initial surface and bulk properties and should be taken into account when diminishing the particle size of LiFePO4. Keeping nanocomposites away from oxidative moisture atmosphere could be a solution to minimize these side reactions. (C) 2007 The Electrochemical Society.