NEW CATHODE MATERIALS FOR LONG LIFE LITHIUM THERMAL BATTERY TECHNOLOGY

The Navy has several military applications that require portable power sources capable of delivering a successiion of repeatable high power pulses for a spectrum of devices. At the present time Li-alloy/FeS2 battery with molten salt electrolyte has the desired characteristics of fast transport and reaction kinetics of the activated materials allowing for the achievement of ultra high specific power from the battery. However, the thermal decomposition of the Fe2 cathode material within the operating temperature range results in loss of obtainable capacity and limited battery lifetimes. We propose to develop new cathode materials with increased thermal stabilities and high discharge rate capabilities compared to FeS2. The cathode materials will consist of single phase mixed transition metal disulfides with the compositions FeX Co(1-X)S2, CoX Ni(1-X)S2 and CuX Ni(1-X)S2. The improved thermal stability, electrode kinetics, and conductivity of the single phase mixed transition metal disulfides are expected to increase the energy and lifetime of the lithium thermal battery. The goal of the Phase II program will be the fabrication and testing of practical cell incorporating the mixed metal disulfide cathode materials with the optimum composition.