KINETICS AND THERMODYNAMICS OF THE LITHIUM INSERTION REACTION IN SPINEL PHASE LIXMN2O4

Electrochemical measurements in the voltage range from 3.0 to 4.0 V versus Li/Li+ have demonstrated the excellent reversibility of the lithium insertion reactions in the spinel phase LixMn2O4. Electrochemical voltage spectroscopy studies indicate the formation of ordering of the inserted lithium ions over the available sites, the ordered phases corresponding to approximate compositions x=0.5 and x=1.0. Cell cycling experiments at various rates show that greater than 1 Li per Mn2O4 can be cycled. This performance corresponds to a material utilization of better than 150 mAh/g. Coupled to the low cell impedance and the relatively facile reaction kinetics, the spinel material is considered a viable material for incorporation into lithium-ion-type battery technology.