| 摘要 |
PURPOSE:To optimize the heat insulating characteristics and strength of a heat insulating layer and improve the battery characteristics by dispersing a heat insulating material mainly made of inorganic fibers in a liquid and filtering the dispersion liquid to form the heat insulating layer so that the density is adjusted according to filtering conditions. CONSTITUTION:Inorganic fibers are used as a heat insulating material and they are dispersed in a dispersion medium, e.g., in water, and a predetermined quantity of a dispersion liquid adjusted to the predetermined density is injected to be filtered between a battery outer case 1 provided on a filtering jig 2 and an electrode dummy section 3. A glass filter, a metal net, filtering cloth, etc. are used as the filtering filter section 4, and they are suitably selected according to filtering conditions, thus the formed density of a heat insulating layer is adjusted according to the ratio of the heat insulating material component in the dispersion liquid and filtering conditions during the filtering process. That is, the density of the heat insulating layer can be adjusted by making the pressure in a decompression chamber 6 variable. Accordingly, after a cylindrical heat insulating layer 10 with a bottom is formed from the inner wall of the battery outer case 1 toward one opening section side, it is removed from the filtering jig and is dried, then a bottom cover 11 is welded. |
