STUDIES TO IMPROVE THE LI SO2CL2 CELL

The performance of the Li/SO2Cl2 primary cell was studied as a functio n of the type of the carbon cathode, cathode catalysts and electrolyte additives. Solutions of LiAlCl4 in SO2 are more conductive than those in SO2Cl2 and, consequently, the electrolyte resistance in the Li/SO2 Cl2 cell decreases during discharge as one mole of SO2 is formed per m ole of SO2Cl2. The replacement of the low during discharge as one mole of SO2 is formed per mole of SO2Cl2. The replacement of the low surfa ce area Chevron acetylene black carbon with the high surface area Ketj enblack carbon cathode increases cell capacity and reduces cathode pol arization. The high surface area carbon, however, causes a deteriorati on in the storability of the cell, manifested as higher self-discharge rate. The use of carefully purified SO2Cl2, and of Ca2+ as an additiv e to the electrolyte, has been found to reduce the voltage delay of th e cells stored at 70-degrees-C. The low temperature discharge capacity of the Li/SO2Cl2 cell can be increased with the addition of SO2. Furt hermore, the added SO2 appeared to improve the storability of the cell s. Cathodes doped with a catalysts consisting of a mixture of polyacry lonitrile and Co, Ni or Fe-salts, after heat treatment at 800-degrees- C, demonstrated 350-500 mV gain in the load voltage at 25mA cm-2. Cata lysed cells stored at 70-degrees-C retained their higher cell voltage but, like the uncatalysed cells, showed a loss in capacity.