Performance of thermal cells and batteries made with plasma-sprayed cathodes and anodes

Cathodes for thermally activated (“thermal”) batteries based on CoS2 and LiCl–LiBr–LiF electrolyte and FeS2 (pyrite) and LiCl–KCl eutectic were prepared by thermal spraying catholyte mixtures onto graphite–paper substrates. Composite separator-cathode deposits were also prepared in the same manner by sequential thermal spraying of LiCl–KCl-based separator material onto a pyrite-cathode substrate. These materials were then tested in single cells over a temperature range of 400–600 °C and in 5-cell and 15-cell batteries. A limited number of battery tests were conducted with the separator-cathode composites and plasma-sprayed Li(Si) anodes—the first report of an all-plasma-sprayed thermal battery. Thermal-spraying offers distinct advantages over conventional pressed-powder parts for fabrication of thin electrodes for short-life thermal batteries. The plasma-sprayed electrodes have lower impedances than the corresponding pressed-powder parts due to improved particle–particle contact.