Systems and methods for separator plates, bipolar plates, stacks of plates, and electrochemical systems, comprising at least one through-opening for the passage of a fluid and a rim that delimits the through-opening. The rim having a curved course and a rectilinear course that adjoins the curved course. A bead arrangement extends around the curved course and the rectilinear course. An edge portion spans the bead arrangement and the rim, so that the bead arrangement is situated at a distance from the rim. A cutout formed in the curved course, so that a minimum distance of the bead arrangement from the rim is smaller in the curved course than in the rectilinear course.

An electrochemical compressor, including a first end plate, a second end plate, a voltage supply connected to the first end plate and second end plate, a plurality of membranes, where each membrane of the plurality of membranes has a substantially same impedance, and where each membrane of the plurality of membranes has a different thickness in a stacking direction, and a plurality of conductive bipolar plates, where the bipolar plates of the plurality of bipolar plates are arranged in contact with, and alternating in the stacking direction with, the membranes of the plurality of membranes, and where the membranes of the plurality of membranes and the bipolar plates of the plurality of bipolar plates are electrically connected in series between the first end plate and second end plate.

Provided is a method of operating an electrolysis apparatus that can inhibit electrode degradation under a variable power supply. The method of operating an electrolysis apparatus includes: an energization step in which electrolysis of electrolyte is performed in an anode compartment including an anode and a cathode compartment including a cathode that are partitioned from each other by a membrane; a suspension step in which electrolysis of electrolyte in the anode compartment and the cathode compartment is suspended; and a discharge step of, in the suspension step, electrically connecting an electrolyzer of the electrolysis apparatus to an external load and adjusting a cell voltage to 0.1 V or less in 5 hours or less.

A bipolar plate for use in an electrochemical device is proposed, in which a flow duct runs between two outer boundary surfaces and extends from a peripheral fluid inlet to a peripheral fluid outlet. As a result, very good cooling of electrochemical cells via a bipolar plate which is in surface contact therewith can be achieved.

A bipolar plate for use in an electrochemical device is proposed, in which a flow duct runs between two outer boundary surfaces and extends from a peripheral fluid inlet to a peripheral fluid outlet. As a result, very good cooling of electrochemical cells via a bipolar plate which is in surface contact therewith can be achieved.

A membrane-electrode-gasket assembly for alkaline water electrolysis, the assembly including: a separating membrane having first and second membrane faces; a first electrode arranged in contact with the first membrane face; and an insulating gasket holding the membrane and the electrode as one body, the gasket including: first and second faces for contacting with anode- and cathode-side frames respectively; a slit part opening toward an inner side of the gasket and receiving the entire peripheries of the membrane and the electrode; first and second parts facing with each other across the slit part; and a continuous part arranged on an outer periphery side of the slit part, uniting the first and second parts into one body, and sealing an outer periphery end of the slit part, wherein the first and second parts sandwich therebetween to hold the entire peripheries of the membrane and the electrode received in the slit part into one body.

Methods and systems related to the field of electrolyzers are disclosed. An electrolyzer assembly is disclosed which includes a stack of cells, a plurality of polar plates in the stack of cells, a plurality of flow fields between the plurality of polar plates, a conduit fluidly connecting flow fields in the plurality of flow fields, an electrically conductive fluid in the conduit, a plurality of insulating layers arranged between a conductive surface of the plurality of flow fields and the conduit, and a plurality of openings in the plurality of insulating layers providing a plurality of fluid connections between the conduit and the plurality of flow fields.

Methods and systems related to the field of electrolyzers are disclosed. An electrolyzer assembly is disclosed which includes a stack of cells, a plurality of polar plates in the stack of cells, a plurality of flow fields between the plurality of polar plates, a conduit fluidly connecting flow fields in the plurality of flow fields, an electrically conductive fluid in the conduit, a plurality of insulating layers arranged between a conductive surface of the plurality of flow fields and the conduit, and a plurality of openings in the plurality of insulating layers providing a plurality of fluid connections between the conduit and the plurality of flow fields.

Electrolysis stack, including multiple layers that are stacked along a stacking direction, wherein each of the layers includes an anode space with an anode, a cathode space with a cathode and a membrane that separates the anode space and the cathode space from each other, wherein the anode space, the membrane and the cathode space are arranged adjacent to each other in the stated order along the stacking direction, and wherein each of the layers further includes a respective electrically insulating shell that surrounds the anode space and the cathode space so as to enclose the anode space and the cathode space radially with respect to the stacking direction, wherein the shell includes a groove on at least one of its end faces in the stacking direction, wherein the groove surrounds the anode space and the cathode space at least partially.

A method of producing hydrogen using a water electrolysis system comprising at least an electrolyzer and a purifier for removing oxygen in a hydrogen gas generated in the electrolyzer. The method includes controlling a concentration of oxygen in a hydrogen gas to be introduced to the purifier to be constantly less than 0.5 volume % when the electrolyzer is operated at least under a current density of 0.5 kA/m.sup.2 or greater; and further controlling Ob/Oa to be less than 10.0, where Oa represents the concentration of oxygen in the hydrogen gas to be introduced to the purifier when the electrolyzer is operated under a current density of 2.0 kA/m.sup.2, and Ob represents the concentration of oxygen in the hydrogen gas to be introduced to the purifier when the electrolyzer is operated under a current density of 0.2 kA/m.sup.2.