The concentration of the oxide ion in the molten salt is quite low upon first assembly of the cell. This means that, before the lithium oxide reaches a saturation in the electrolyte, the open circuit voltage will be greater than the value in Table , due to the effect of mixing entropy of the Li2O in the molten salt. However, after reaching the solubility of Li2O in the LiCl-KCl mixture (about 1 mol % at 550°C ) the open circuit voltage remains fixed at 2.56V. Interestingly based on the amount of lithium oxide discharged between the initial state and the state which reaches 2.56V, we would not expect the solubility limit to be reached. One possible rationalization for this observation is that other oxide ions have been dissolved into the solution from the YSZ and LLZO tubes, making precipitation of Li2O favorable even at low amounts of charge passed.