The Effect of MgO-MgF2 Synthesis Method on the Electrolyte Binding Ability in Thermal Batteries

摘要

This paper describes a comparative study of synthesis (sol-gel and suspension methods) of MgF-(2-)MgO material used as an immobilizing agent of the electrolyte (KCl-LiCl-RbCl) for high temperature cells. Samples containing 20 mol.% MgF2 obtained by the sol-gel method, followed by calcination at 500 and 600℃, were characterized by large specific surface areas greater than those of samples obtained by the suspension method. It was demonstrated that pellets containing 40 wt.% immobilizing agent composed of 20 mol.% MgF2 - 80 mol.% MgO, obtained by the sol-gel method, and calcinated at 500 ℃, were good electrolyte immobilizers. This mixture remains dimensionally stable at 400 ℃ and under 60 kPa pressure (no leakage of the electrolyte was observed) and reveals good ionic conductivity during tests in a model cell - the voltage was not less than 1.0 V and current more than 0.75 A for approximately 400 s.