Abstract: The present invention discloses a manufacturing method of a sodium-sulfur storage battery comprising battery components of metallic members jointed by means of a thermocompression method to an .alpha.-alumina ring which is jointed to a sodium ion conductive solid electrolytic tube using solder glass. According to the invention, thicknesses of the metallic members thermocompressively jointed to upper and lower surfaces of said .alpha.-alumina ring is in a range from about 0.2 mm to about 0.6 mm. Plate-shaped aluminum rings are disposed between said .alpha.-alumina ring and said metallic members respectively and are thermocompressively jointed in air under condition of a temperature in a range from about 600.degree. to about 625.degree. C. and a pressure in a range from about 1200 to about 1600 kg/cm.sup.2.

Abstract: The invention relates to multilayer heat insulators wherein gas-impermeable layers each made of a metal foil of one member selected from the group consisting of aluminum, nickel and stainless steel and gas-containing layers each made of at least one member selected from the group consisting of glass fiber, asbestos fiber, mineral fiber, ceramic fiber, carbon fiber, silica powder, alumina powder and zirconia powder in the form of wool, paper or mat are laminated alternately so that the same layers do not contact each other. The thickness of the gas-impermeable layer is 10 to 20 .mu.m, the thickness of the gas-containing layer is 0.3 to 1.8 mm and its porosity is 0.98 to 0.95 to make the thermal conductivity of this laminated multilayer heat insulator about 0.02 kcal/mh.degree. C. (200.degree. C.) so that the behavior of the contained gas may be as small as possible, the thermal conduction may be prevented and the heat insulating performance may be improved.