JOINT STRUCTURE OF INSULATION RING AND POSITIVE ELECTRODE CYLINDRICAL FITTING FOR SODIUM-SULFUR BATTERY

摘要

PROBLEM TO BE SOLVED: To prevent the occurrence of damages of the jointed part between an insulation ring and a positive electrode cylindrical fitting by improving the strength reliability of that part against a load caused by a thermal contraction difference between a solid electrolyte tube and a positive electrode vessel at the time of a battery temperature drop. SOLUTION: An insulation ring 4 is jointed to the open end of solid electrolyte tube 5, and a positive electrode cylindrical fitting 3 having a cylindrical part 3a and a flange part 3b bulged inward from the lower end thereof is thermocompression jointed to the insulation ring 4 so that the upper surface of the flange part 3b is jointed to the lower edge face of the insulation ring 4. Regarding the jointed structure of the insulation ring 4 and the positive electrode cylindrical fitting of a sodium-sulfur battery so constructed, the value C of clearance 13 between the internal circumferential surface of the cylindrical part 3a of the positive electrode cylindrical fitting 3 and the external circumferential surface of the insulation ring 4 is 0.15 mm or less.