Journal of The Electrochemical Society

Mechanistic studies of the reactions in Li-SOC12 cells have been undertaken to improve understanding of the safety problems of these cells. The electrochemical reduction of 1.5M LiA1C1JSOC12 has been investigated using gas chroma-tography, electron spin resonance spectroscopy, and infrared spectroscopy. C12 and $2C12 have been identified as inter-mediates in the reduction of SOC12, along with a radical species (g ~ = 2.004, g~, = 2.016, g = = 2.008) and the proposed triplet ground-state dimer of this radical. SO ~ and sulfur have been identified as products. Based upon these findings, a mechanism for the electrochemical reduction of 1.5M LiA1C1JSOC12 has been proposed, and its implications for safety of Li-SOC12 cells during discharge to +0.5V at 25°-30°C are discussed. There has been great interest in the lithium thionyl chloride battery system because of its high energy den-sity. The solvent, thionyl chloride (SOC12), is also the cath-ode active material, so this cell has the potential for high rate discharge. Despite much progress in the areas of de~ sign and optimization of cells and elimination of voltage delay, safety problems till hinder the application of the