IMPROVEMENT IN THE CAPACITY AND SAFETY OF LITHIUM/INORGANIC ELECTROLYTE SULFUR DIOXIDE RECHARGEABLE CELLS

THE OBJECTIVE IS TO INCREASE THE CAPACITY AND SAFETY OF THE LITHIUM/ LIALCL4.6SO2/CARBON RECHARGEABLE CELL BY ALTERING THE ELECTROLYTE AND THE POSITIVE ELECTRODE, AND BY IMPROVING THE METHODS CURRENTLY EMPLOYED FOR MAKING THE ELECTROLYTE. ALUMINUM IS REMOVED AS DISCHARGE PROCEEDS, SINCE ONE OF THE PRODUCTS IS AN INSOLUBLE COMPLEX BETWEEN THE ALUMINUM, REDUCED SO2, AND THE CARBON SURFACE. THE DILEMMA IS THAT ADDING MORE ALUMINUM AS LIALCL4, WHILE IT MIGHT IMPROVE THE CAPACITY, WOULD ALSO RAISE THE ELECTROLYE FREEZING POINT TO AN UNACCEPTABLE HIGH LEVEL. WE PROPOSE TO CHANGE THE COMPOSITION OF THE ELECTROLYTE SUCH THAT THE LOW FREEZING POINT IS MAINTAINED, YET ADDING SOLUTES WHICH ARE LIKELY TO INCREASE THE CAPACITY. IN ADDITION, INSOLUBLE MATERIALS WHICH COULD BE INSTRUMENTAL IN INCREASING THE CAPACITY BY ENCOURAGING THE FORMATION OF COMPLEXES SIMILAR TO THE ONE WHICH FORMS ON THE KETJENBLACK NOW USED IN THESE CELLS WILL BE ADDED TO THE CARBON POSITIVE ELECTRODE. WE EXPECT IMPROVEMENTS IN SAFETY THROUGH THE ADDITION TO THE ELECTROLYTE OF MATERIALS WHICH WOULD IMPROVE THE MORPHOLOGY OF THE PLATED LITHIUM.