A lithium-ion cell with an inorganic electrolyte

A novel rechargeable cell is described in which a carbon based negative electrode operates in an inorganic electrolyte containing sulfur dioxide. The discharge reaction involves the reduction of sulfur dioxide at a positive electrode composed of carbon. Both the negative and the positive electrodes thus consist of carbon, the former of graphite or a low surface area carbon, and the latter of a high surface area carbon. Lithium ions are introduced into the carbon electrodes from a sacrificial lithium electrode. This system combines the safety advantages of a non-metallic negative electrode with the excellent reversibility of the sulfur dioxide depolarizer. Because no metal oxide cathode is used, only abundant and inexpensive materials are required.