ADVANCED LITHIUM RECHARGEABLE INORGANIC ELECTROLYTE BATTERY

This project will evaluate the low temperature (to -55 degrees C) performance of the Li/CuCl*2* and Li/LixCo0*2* rechargeable cells with SO*2* electrolytes to determine if one of these battery systems should be developed as a power source for aircrew survival-rescue equipment. The excellent cycle life and specific energy (e.g. 200 deep cycles at 165 Whr/Kg), wide operating temperature range, low self-discharge rate and ruggedness make the Li/CuCl*2* system particularly attractive for such an application. The approach in Phase I will be to characterize the low temperature 1.1 mA/cm^2 continuous discharge and 10-50 mA/cm^2 pulse discharge performance of 80 mAhr size laboratory cells at 23, -20 and -55 degrees C and then to evaluate the performance again after a number of innovative improvements to the positive electrode, electrolyte and cell design. Innovations that will receive particular emphasis will include reducing the particle size of the positive electrode active materials and conductive additives, modifying the crystal structure or purity of the active material and changing the electrolyte salt and adding volatile cosolvents. The construction and testing of rechargeable cells with 7.6 cm diameter bipolar electrodes will be undertaken to evaluate the merits of the bipolar electrode design as a means to increase the volumetric energy density for low temperature applications.