Abstract: An electrolyzer for alkaline electrolysis of water has a diaphragm-electr sandwich arrangement wherein a predetermined narrow spacing to provide a minimum distance is maintained between the diaphragm surface and the superjacent electrode. The spacing is provided by a single layer of a filament of predetermined thickness disposed in an array. The filament is strung in a plurality of lengths disposed in a common plane so that the thickness of the spacing is the same as the thickness of the single layer which is equal to the filament thickness. The array is secured by a retaining wire which engages a groove provided in a cell frame of the electrolyzer. The filament is made of plastic material which can withstand electrolysis conditions. An apparatus and method for stringing the filament to provide the array are also described.

Abstract: A diaphragm for alkaline electrolysis, specifically for alkaline electrolysis of water, comprises a fine-pored, predominantly ceramic layer, which is preferably supported by a superficially oxidized structural framework or mesh. The diaphragm in use is sandwiched between two electrodes and is provided, on one or both sides, with fairly coarse-grained protuberances distributed over the surface and embedded into the fine-pored predominantly ceramic layer, which grains project out of the diaphragm surface. In view of the projection of the grains to form protuberances, and in spite of the fact that the adjacent electrodes are in contact with the diaphragm, a certain minimum distance is maintained between the diaphragm and each electrode, whereby, deposits on the electrodes, caused by unavoidable corrosion phenomena within the electrolysis apparatus, cannot propagate into the diaphragm.

Abstract: The invention concerns a NiO-based ceramic oxide diaphragm for the alkaline water electrolysis. The diaphragm, in accordance with the invention, contains 0.5 to 10% by weight (estimated as Ti based on the oxide mass) of titanium oxide in the porous NiO layer. Diaphragms of this type are obtained, in particular, by the oxidative sintering of a mass of nickel powder which has been applied under pressure to a nickel support, especially one consisting of nickel wire gauze. In the process the titanium is in the form of titanium metal, titanium oxide or a titanium compound which is added to the initial nickel powder. The titanium is present in the form of its oxide after the oxidation sintering treatment. In an alternative embodiment of the process, an already sintered porous mass of nickel or nickel oxide can be impregnated with a titanium compound and calcined to convert the titanium compound to its oxide.