Chemistry

The cell reaction of the Lithium - Thionyl chloride system is : 4Li + 2 SOCl₂ -> 4LiCl + S + SO₂(g)

Lithium metal acts as anode while the liquid thionylchloride (SOCl₂) acts as both electrolyte and cathode material, discharging at a porous carbon electrode acting as current collector. During the cell reaction, Lithium metal dissolves in the electrolyte as lithium ions while at the surface of the carbon electrode thionylchloride is being discharged. The SO₂ is dissolved in the electroyte, preventing internal pressure build up . The open cell voltage for such a cell is 3.65V and it is capable of delivering high currents, even at temperatures as low as -40°C, where still more than 50% of its capacity is available.

Construction

In Thales lithium batteries the thionylchloride electrolyte is retained in a glass ampule suspended in a special construction that allows the ampule to break out of the suspension and shatter by a minimum acceleration of 1500 g up to 5000 g where higher flick ramming forces are present. In most applications the electrolyte distribution is enhanced by spin forces, but even without these forces, activation rise time is very short.

The stainless steel housing allows for flexible one cell or multi cell stacks of up to 9 cells in the present design. Parallel cell connection can handle even larger current densities.

Recent design improvements have increased the drop resistance to withstand drops up to 5 metres and still achieve 100% activation at forces as low as 800 g.

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Versions Use Identical Stainless Steel Housing