Fast Charging LiFePO_4

摘要

An excellent fast charging ability for olivine LiFePO_4 is demonstrated with respect to its advantageous open-circuit voltage of 3. V vs. Li/Li~+ with an appropriately large overvoltage margin to the electrolyte oxidation, structural integrity under the nonequ librium state induced by the large overpotential, and moderate electrochemical activity easily enhanced to the practical level b efficient nanocomposite formation. The current relaxation to the applied stepwise voltage of 4.2 V vs. Li/Li+ for the Li_xFePO_4 wa fast enough to consume most of the theoretical capacity within 10-20 min and the speed is competitive with that of the conver tional electrode composite of Li_x-Mn_2O_4. while the capacity consumption of Li_xMnPO_4 under the identical experimental cond: tions was almost null.