Abstract: Thermocompression methods of forming sodium-sulfur cell casings are described. One method includes positioning an assembly within a die, the assembly having an inward flange at one end of an open ended metallic container positioned against an aluminum washer adjacent each opposite major surface of an electrically insulating ceramic ring, applying pressure to each flange within its respective container, and heating the assembly in an inert atmosphere to bond the containers to the ceramic ring. Another method includes the above steps except that the pressure is applied to the opposite edge of each container.