IMPROVED TUBESHEET AND TUBESHEET/HOLLOW FIBRE ASSEMBLY FOR HIGH-TEMPERATURE BATTERY CELLS, AND METHOD OF MANUFACTURING SAME

摘要

A small amount of SiO2 is added to a sodium borate solder glass for making tubesheets in hollow fiber, high temperature battery cells. The glass is more easily ground and has a lower softening temperature. When the powdered glass is fused, to form the tubesheet and sealingly engage the fibers (3), the fiber-weakening fluxing action of the glass is considerably reduced. The invention also resides in a method of making the tubesheet whereby the internal structure is modified so that it has a closed upper surface (2) while the underlying structure of the tubesheet is more open or porous (1).