Sodium-sulphur electric cell and method of forming same

Claim 1

A method of producing a sodium-sulphur type electric cell, said cell comprising: a cathode tank for containing a cathode reagent which is liquid at operation temperature and is a material selected from the group consisting of sulphur, phosphorus, selenium and alkaline salts of these substances; at least one solid electrolyte tube closed at its bottom end, for containing an anode reagent which is liquid at operation temperature, said tube consisting of an alkaline metal and being disposed in said cathode tank so as to be immersed in said cathode reagent, the walls of said tube being made of beta sodium alumina; a support of an insulating ceramics substance for holding said electrolyte tube in said cathode tank, a glass part connecting said support to said tube; an anode tank for containing a store of said anode reagent and being disposed above said cathode tank, so that said electrolyte tube opens at its top into said anode tank, said support separating the open ends of said anode tank and of said cathode tank; said method comprising: first, forming the connection between said electrolyte tube and said support of an insulating ceramics substance; and successively disposing said tanks on either side of said support with flanges provided at their open ends and with said tanks substantially concentric with said electrolyte tube; inserting an O ring repsectively between the flanges of the tanks and said ceramics support; heating the assembly to a temperature close to but lower than the melting point of the material constituting said O rings while maintaining compressive pressure on said flanges; cooling the assembly down to ambient temperature; and disposing at least one bushing previously in contact with at least the bottom part of the wall of each of said tanks with said bushings bearing on respective faces of said insulating ceramics support prior to heating said assembly.

Claim 2

A method of producing a sodium-sulphur type electric cell, said cell comprising: a cathode tank for containing a cathode reagent which is liquid at operation temperature and is a material selected from the group consisting of sulphur, phosphorus, selenium and alkaline salts of these substances; at least one solid electrolyte tube closed at its bottom end, for containing an anode reagent which is liquid at operation temperature, said tube consisting of an alkaline metal and being disposed in said cathode tank so as to be immersed in said cathode reagent, the walls of said tube being made of beta sodium alumina; a support of an insulating ceramics substance for holding said electrolyte tube in said cathode tank, a glass part connecting said support to said tube; an anode tank for containing a store of said anode reagent and being disposed above said cathode tank, so that said electrolyte tube opens at its top into said anode tank, said support separating the open ends of said anode tank and of said cathode tank; said method comprising: first, forming the connection between said electrolyte tube and said support of an insulating ceramics substance; and successively disposing said tanks on either side of said support with flanges provided at their open ends and with said tanks substantially concentric with said electrolyte tube; inserting an O ring repsectively between the flanges of the tanks and said ceramics support; heating the assembly to a temperature close to but lower than the melting point of the material constituting said O rings while maintaining compressive pressure on said flanges; cooling the assembly down to ambient temperature; and disposing at least one bushing previously in contact with at least the bottom part of the wall of each of said tanks with said bushings bearing on respective faces of said insulating ceramics support prior to heating said assembly.

Claim 5

A method according to claim, 1 wherein said temperature lies between 550° and 630° C, and said pressure lies between 50 and 600 Bar and is maintained for a period of 5 minutes to 1 hour.