Pressurised Electrolysis Stack

An electrolysis stack (2) for an electrolyser (20) is disclosed. The electrolysis stack (2) comprises a plurality of electrolysis cells each comprises two electrodes and a (porous) gas separating membrane and a cell frame (6, 6', 6'') having a circular outer periphery. The cell frames (6, 6', 6'') are arranged adjacent to each other: The electrolysis stack (2) comprises means (18) for supplying electrolyte feed to the interior of the electrolysis cells and means (16) for removing oxygen gas and hydrogen gas from the electrolysis cells. The electrolysis stack (2) comprises electric power point members (46, 46') constituting a cathode, an anode or a cathode and an anode. The electrolysis stack (2) comprises at least one support member (12, 12', 42, 42', 42'') arranged at the outside periphery of the cell frames (6, 6', 6'').