Published online by Cambridge University Press: 16 February 2011
Transition metal oxides have been evaluated extensively in the past as cathode materials for lithium cells. The major emphasis of recent research has been to develop lithium-ion or rockingchair cells that are assembled in the discharged state with a lithiated transition metal oxide cathode and a carbon anode. Although these cells are significantly safer to use than lithium cells with metallic lithium anodes, the possibility of depositing lithium at the surface of the carbon particles at the top of charge or at high rates of charge cannot be discounted. This paper discusses some recent developments in fabricating rocking-chair cells with transition metal oxide host structures as both anode and cathode, the anode providing a relatively low voltage vs. lithium and the cathode a relatively highvoltage vs. lithium. These cells avoid the reduction and oxidation of lithium during charge and discharge and, therefore, reduce the safety hazards of lithium cells. Improved safety is gained, however, at the expense of cell voltage and specific energy.