lithium-thionyl chloride cell

Lithium-thionyl chloride batteries are a type of primary battery, meaning they are discharged once and then discarded. They offer the highest energy and power density commercially available.1

These batteries utilize lithium as the anode and thionyl chloride as both the electrolyte solvent and cathode material. A protective film of lithium chloride forms on the lithium anode, preventing a reaction with the liquid cathode. The cathode itself is made of porous carbon powder.1

Lithium-thionyl chloride batteries are notable for their impressive performance at room temperature and even at very low temperatures, down to -54 °C (-65 °F). However, due to the corrosive and toxic nature of thionyl chloride, these batteries must be handled with care and not opened or disposed of casually. They are often used in military equipment, aerospace systems, and personal pagers.1