Modification of MgO as an immobilizing agent for molten electrolyte

This paper describes the synthesis and texture of the MgF2-MgO system used as an immobilizing agent of the electrolyte (KCl-LiCl-RbCl) for high-temperature cells. Preparations containing 20 and 40 mol% MgF2 were characterized by a mesoporous structure and large specific surface areas. It was demonstrated that pellets containing 40-50 mas.% of MgF2-MgO immobilizing agent were good electrolyte immobilizers. The ionic conductivity of pellets investigated in this work ranged from 0.02 to 0.04 S/cm, and it was about 20 times lower than the value set for the pure electrolyte. The difference is due to the tortuosity of the pellet. This mixture remains dimensionally stable at 400 A degrees C and under 60 kPa and reveals good ionic conductivity during tests in a model cell with a 1.32-Omega resistor. During the discharge of the cell, it was observed that the voltage was not less than 1.5 V and current more than 1 A for approximately 100 s. No leakage of the electrolyte was observed.