摘要 |
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. These coarse grains, about 10-250 microns in size, are thinly distributed over the diaphragm surface during the manufacture of the diaphragm before sintering, and are caused to be embedded in the surface with a slight application of pressure, so that they stick out in the form of "nubs", resulting in reduced energy consumption during electrolysis.
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