LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA MATERIALS SCIENCES LAB
This program, to develop batteries based on the lithium-cupric fluoride and lithium-cobaltic fluoride couples, was concerned with the development of components as well as battery design. Propylene carbonate and butyrolactone were the most stable solvents studied and the majority of effort was with these solvents. Conductivities were measured with solutions of NH4PF6 in propylene carbonate and several fluorine complex salts in butyrolactone. Solutions of NaPF6 in propylene carbonate had reasonable stability and were moderately successful as electrolyte for cell tests. Solutions of LiClO4 in propylene carbonate gave by far the best discharges. Lithium anodes were prepared from lithium strip and despersions and gave similar results on cell test. The selection of either type for use in batteries will depend upon fabrication simplicity. Resistance, electrolyte absorption, and retention were measured for selected separator material. Absorption was generally low for materials compatible with these cell systems. Sustained cell discharges with a voltage plateau were not obtained with Li-CoF3 cells even at current densities of 0.5 mAsq. in. The best cell had 58 utilization of CuF2 with a cell voltage above 3.0 V and delivered 60 W-hrlb of cell weight. About one third of the cell weight was electrolyte and improved figures would be expected with larger cells where the electrolyte would be a smaller proportion of the cell weight.