DEVELOPMENT STATUS OF LITHIUM-SILICON-IRON SULFIDE LOAD-LEVELING BATTERIES.

These batteries use a molten LiCl-KCl electrolyte, and are operated at a temperature of 400 degree C or higher. The lithium-silicon alloy, Li//5Si, is used as the active material in the negative electrodes. Positive electrodes contain the iron sulfides, FeS, FeS//2, or their mixture. Electrode development tasks are concerned with minimizing the weight and cost of supporting structures, and optimizing electrode performance. Porous ceramic separators, based upon rigid structural materials are being developed. Cell development is being conducted through scale-up stages involving increasing electrode area and numbers of parallel-connected electrodes to reach a full-size modular cell.