Primary Li/SOCL Cells XI. SOCI Reduction Mechanism in a Supporting Electrolyte

The electrochemical reduction of SOC12 has been investigated in organic solvents with supporting electrolytes, using cyclic voltammetry, coulometry, and UV-VIS spectroscopy. An overal l 2.0F reduction was observed. Compari-son of vol tammograms of SO2, S, and 82C12 with those of reduced SOC12 solu-tions demonstrated that intermediate species are formed in the reduction of SOC12. These intermediates decompose slowly to form S and SO2. Reaction mechanisms consistent with these findings are discussed. The Li/SOC12 inorganic electrolyte cell is the highest energy density system known to date (1-4). It consists of a l i thium anode, a carbon cathode, and thionyl chloride, which functions both as solvent and cath-ode active material. Whi le this system has been subject to intense development, there exist questions with regard to cell chemistry and cell safety. The cell stoi-chiometry [1] suggested or iginal ly by Dey and Schla ik jer (4) is the most general ly accepted one. The reaction involves the formation of sulfur and sul-fur dioxide in equimolar amounts, and the quant i ta-t ive precipitat ion of LiC1 (13) based on 2 F /mole of SOC1