Lithium Cells

Lithium battery chemistry consists of a number of cell designs that use lithium as the anode. Lithium is gaining a lot of popularity as an anode for a number of reasons.

Comparison of anode materials :

Lithium, the lightest of the metals, also has the highest standard potential of all the metals, at over 3 V. Some of the lithium cell designs have a voltage of nearly 4 V. This means that lithium has the highest energy density. Many different lithium cells exist because of its stability and low reactivity with a number of cathodes and non-aqueous electrolytes. The most common electrolytes are organic liquids with the notable exceptions of SOCl2 (Thionyl chloride) and SO2Cl2 (sulfur chloride). Solutes are added to the electrolytes to increase conductivity.

Lithium cells have only recently become commercially viable because lithium reacts violently with water, as well as nitrogen in air. This requires sealed cells. High-rate lithium cells can build up pressure if they short circuit and cause the temperature and pressure to rise. The cell design needs to include weak points, or safety vents, which rupture at a certain pressure to prevent explosion.

Lithium cells can be grouped into three general categories: liquid cathode, solid cathode, and solid electrolyte.