2. Lithium sulfur dioxide batteries

2.1 General

Lithium-sulfur dioxide batteries (Li/SO ₂ ) are liquid-cathode batteries: sulfur dioxide is liquid at low pressures (a few bars at room temperature), and is mixed with acetonitrile to dissolve sufficient lithium bromide as electrolyte. This electrochemical generator, with an open-circuit voltage of close to 3 V, was already mentioned in the mid-1960s [13] ; it enabled high currents to be generated, leading to high power-to-weight ratios: the very good conductivity of sulfur dioxide media – acetonitrile – alkali salts (of the order of 5 · 10 ^-2 S/cm at 20 ˚C with LiBr), even at 0 ˚C, means that these batteries can operate...