Solid Cathode Lithium Battery Chemistry

These cells cannot be used in high-drain applications and don't perform as well as the liquid cathode cells in low temperatures. However, they don't have the same voltage delay and the cells don't require pressurization.

They are used generally for memory backup, watches, portable electronic devices, etc.

LiMnO2

These account for about 80% of all primary lithium cells, one reason being their low cost. The cathode used is a heat-treated MnO2 and the electrolyte a mixture of propylene carbonate and 1,2-dimethoyethane. The half reactions are :

At lower temperatures and in high-rate discharge, the LiSO2 cell performs much better than the LiMnO2 cell. At low-rate discharge and higher temperatures, the two cells perform equally well, but LiMnO2 cell has the advantage because it doesn't require pressurization.

Li(CF)n Lithium Polycarbon Monofluoride

The cathode in this cell is carbon monofluoride, a compound formed through high-temperature intercalation. This is the process where foreign atoms (in this case fluorine gas) incorporate themselves into some crystal lattice (graphite powder), with the crystal lattice atoms retaining their positions relative to one another. A typical electrolyte is lithium tetrafluorobate (LiBF4) salt in a solution of propylene carbonate (PC) and dimethoxyethane (DME).

These cells also have a high voltage (about 3.0 V open voltage) and a high energy density(around 250 Wh/kg). All this and a 7-year shelf life makes them very suitable for low- to moderate-drain use, e.g., watches, calculators, and memory applications.