Advances in ambient temperature secondary lithium cells

Abstract

JPL is carrying out a NASA/OAST sponsored R &D program on the development of ambient temperature secondary lithium cells for future space applications. The goal of the program is to develop secondary lithium cells with a 100 W h kg −1 specific energy and capable of 1000 cycles at 50% DOD. The approach towards meeting these goals initially focussed on several basic issues related to the cell chemistry, selection of cathode materials and electrolytes, and component development. We have examined the performance potential of LiTiS 2, LiMoS 3, LiV 6O 13 and LiNbSe 3 electrochemical systems. Of these four, the LiTiS 2 system was found to be the most promising in terms of achievable specific energy and cycle life. Major advances to date in the development of LiTiS 2 cells are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly. This paper summarizes these advances made at JPL on the development of secondary lithium cells.