Insulating seal for molten salt battery

Claim 2

IN A HIGH TEMPERATURE ELECTRO-CHEMICAL CELL, HAVING A CHAMBER CONTAINING ELECTROLYTE AN ELECTRODE FOR ONE OF THE CELL''S REACTANTS CONTACTING SAID ELECTROLYTE, A COUNTERELECTRODE FOR ANOTHER OF THE CEL''S REACTANTS CONTACTING SAID ELECTROLYTE AND SPACED APART FROM SAID ELECTRODE THROUGH SAID ELECTROLYTE AND AN ELECTROLYTE-TIGHT INSULATING SEAL ELECTRICALLY ISOLATING SAID ELECTROLYTE COUNTERELECTRODE AND DEFINING PART OF SAID CHAMBER THE IMPROVEMENT COMPRISING SAID SEAL CONSISTING ESSENTIALLY OF SOLID LITHIUM FLUORIDE AND A MEANS FOR MITITGATING THE EFFECTS OF LITHIUM FLUORIDE''S THERMAL EXPANSION PROPERTIES, AND SAID ELECTROLYTE COMPRISING A MIXTURE OF LITHIUM FLUORIDE AND A SALT WHICH WHEN FUSED IONICALLY CONDUCTS THE CELLS CURRENT, WHEREIN THE LITHIUM FLUORIDE PRESENT IN THE ELECTROLYTE IS SUFFICIENT TO SUBSTANTIALLY SATURATE THE FUSED SALT AND THE FUSED SALT HAS A DECOMPOSITION POTENTIAL LESS THAN SAID LITHIUM FLUORIDE.

Claim 3

In a high temperature electro-chemical cell, having a chamber containing electrolyte, an electrode for one of the cell''s reactants contacting said electrolyte, a counterelectrode for another of the cell''s reactants contacting said electrolyte and spaced apart from said electrode through said electrolyte, and an electrolyte-tight insulating seal electrically isolating said electrode from said counterelectrode and defining part of said chamber, the improvement comprising: said seal consisting essentially of a solid sintered mass of lithium fluoride particles having a density of at least about 2.5 g/cc and being replete with a plurality of intergranular slip planes for permitting movement of the particles with respect to each other when the mass is thermally stressed; and said electrolyte comprising a mixture of lithium fluoride and a salt which when fused ionically conducts the cell''s current, wherein the lithium fluoride present in the electrolyte is sufficient to substantially saturate the fused salt and the fused salt has a decomposition potential less than said lithium fluoride.

Claim 4

In a high temperature electro-chemical cell, having a chamber containing electrolyte, an electrode for one of the cell''s reactants contacting said electrolyte, a counterelectrode for another of the cell''s reactants contacting said electrolyte and spaced apart from said electrode through said electrolyte, and an electrolyte-tight insulating seal electrically isolating said electrode from said counterelectrode and defining part of said chamber, the improvement comprising: said seal consisting essentially of a solid sintered mass of lithium fluoride particles having a density of at least about 2.5 g/cc and being replete with a plurality of intergranular slip planes for permitting movement of the particles with respect to each other when the mass is thermally stressed; and said electrolyte comprising a mixture of lithium fluoride and a salt which when fused ionically conducts the cell''s current, wherein the lithium fluoride present in the electrolyte is sufficient to substantially saturate the fused salt and the fused salt has a decomposition potential less than said lithium fluoride.