Fast Charging LiFePOsub 4

An excellent fast charging ability for olivine is demonstrated with respect to its advantageous open-circuit voltage of 3.4 V vs. with an appropriately large overvoltage margin to the electrolyte oxidation, structural integrity under the nonequilibrium state induced by the large overpotential, and moderate electrochemical activity easily enhanced to the practical level by efficient nanocomposite formation. The current relaxation to the applied stepwise voltage of 4.2 V vs. for the was fast enough to consume most of the theoretical capacity within 10-20 min and the speed is competitive with that of the conventional electrode composite of while the capacity consumption of under the identical experimental conditions was almost null. © 2004 The Electrochemical Society. All rights reserved.