Performance of lithium-sulfur dioxide rechargeable cells

The lithium-sulfur dioxide rechargeable system has been investigated with LiAlCl₄ electrolyte in hermetically sealed experimental cells. Over 50 cells were tested at 1-5 mA/cm² discharge and 0.5-2 mA/cm² charge rates using carbon cathode material to evaluate cycle life and capacity at ambient (21°C) and low (-30°C) temperatures. Most of the cells delivered excellent cycle life with significantly higher capacity than that reported in the literature. Optimization of the cathode process, cell configuration, and electrochemical voltage limits was critical in obtaining high cell capacity and cycle life. Results of scanning electron microscopy of charged and discharged Li anodes and X-ray diffraction analysis of carbon cathodes are also presented