Differential scanning calorimetry studies of possible explosion-causing mixtures in Li/SO2 cells

Investigation of Lithium Sulfur Dioxide (Li/SO2) Battery Safety Hazard

“…There has been a number of reported thermal studies (12, 19,22--26) however, few chemical studies have been carried out (12,16,18,27,28).…”

“…Lithium dithionite is believed to be the sole cathode product formed upon discharge to 1.5V, however, attempts to quantitatively IeterminzŽ it have given less trian theoretical amounts (12).…”

“…However, in the presence of SO 2 the surface of the Li anode is passivated, presumably by the formation of a layer of Li 2 S 2 0 4 , providing a kinetic stability to the system (10,12).…”

“…The presence of an impurity such as water can affect the behavior of the cell by altering the protective Li 2 S 2 0 4 layer on the lithium, by causing the decomposition of products such as Li 2 S 2 0 4 , or by catalyzing undesired exothermic reactions in the cell (12,46).…”

“…Lithium is thermodynamically unstable in the presence of acetonitrile and reacts exothermically, forming methane gas and other products (12)(13)(14)(15). However, in the presence of SO 2 the surface of the Li anode is passivated, presumably by the formation of a layer of Li 2 S 2 0 4 , providing a kinetic stability to the system (10,12).…”