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 ve rsus Li/Li+ have demonstrated the excellent reversibility of the lithi um insertion reactions in the spinel phase LixMn2O4. Electrochemical v oltage spectroscopy studies indicate the formation of ordering of the inserted lithium ions over the available sites, the ordered phases cor responding to approximate compositions x=0.5 and x=1.0. Cell cycling e xperiments at various rates show that greater than 1 Li per Mn2O4 can be cycled. This performance corresponds to a material utilization of b etter than 150 mAh/g. Coupled to the low cell impedance and the relati vely facile reaction kinetics, the spinel material is considered a via ble material for incorporation into lithium-ion-type battery technolog y.