Preparation and characterization of LiFePO4 from NH4FePO4•H2O under different microwave heating conditions

Olivine-type LiFePO4 is a very promising polyanion-type cathode material for lithium-ion batteries. In this work, LiFePO4 with high specificity capacity is obtained from a novel precursor NH4FePO4 center dot H2O via microwave processing. The grains grow up in the duration of sintering until they reach the decomposition temperature. The apparent conductivity of the samples rises rapidly with the irradiation time and influences the electrochemical performance of the material greatly at high current density. As a result, the LiFePO4 cathode material obtained with a sintering time of 15 min has good electrochemical performance. Between 2.5 and 4.2 V versus Li, a reversible capacity is as high as 156 mAh g(-1) at 0.05 C.