A novel rechargeable lithium composite cathode system

A new type of rechargeable lithium cell is under development which consists of the lithium salt of a sulfur oxy-acid and a transition metal oxide. The selection, composition and thermal history of the starting oxides and the incorporation of the lithium salt are crucial factors which govern cell performance. A high energy has been demonstrated and shown to be commensurate with the higher ratio of lithium to metal oxide which can be intercalated and deintercalated in comparison with state-of-the-art cathode systems based on cobalt, nickel and manganese oxides. A model of the cell chemistry changes which take place on cycling is proposed and discussed.