The objective of the program described is to develop the technology required to construct secondary batteries having the performance capabilities required for pollution-free electric automobiles. Lithium/sulfur cells using a molten lithium halide-containing electrolyte and operating at 360 to 390 C have achieved capacity densities of up to 0.52 A-hr/sq cm (above 1 V) at a current density of 0.52 A/sq cm. The cell development program is supported by laboratory studies in various areas. The solubility of cathode materials in various electrolytes and the identity of the soluble species are studied. Preliminary results indicate that electrolytes containing only fluoride and chloride anions have the lowest solubility for sulfur-bearing species. A survey of candidate solid electrolytes has led to the investigation of the lithium form of B-alumina. Investigations were made of the corrosion rates of various materials at 375 C, and battery design and performance calculations were carried out for a 1075-lb Li/s battery in a 4300 lb electric automobile. (Author)