Multi-cell COx electrolyzer stacks

A COx electrolyzer apparatus comprising:

• a first end assembly comprising a first end plate and a cathode interface assembly;
• a second end assembly coupled to the first end assembly by a plurality of tensioning members;
• a plurality of repeat units stacked along an axial direction and positioned between the first end assembly and the second end assembly, each repeat unit comprising:
• a cathode side comprising:
• a cathode frame that defines a first opening;
• and
• a cathode flow field at least partially disposed in the first opening;
• an anode side comprising:
• an anode frame that defines a second opening;
• and
• an anode flow field at least partially disposed in the second opening;
• a separator plate positioned between the cathode frame and the anode frame;
• a plurality of frame fasteners that couple the cathode frame and the anode frame to one another, wherein the frame fasteners are different from the tensioning members;
• a membrane electrode assembly (MEA) having a cathode layer, an anode layer, and a membrane positioned between the cathode layer and the anode layer, wherein the MEA is positioned between the cathode side of a first repeat unit among the plurality of repeat units and the anode side of a second repeat unit among the plurality of repeat units such that the cathode side of the first repeat unit is adjacent to the cathode layer of the MEA and the anode side of the second repeat unit is adjacent to the anode layer of the MEA;
• the cathode side of the first repeat unit, the anode side of the second repeat unit, and the MEA positioned therebetween defining a COx electrolyzer cell such that the plurality of repeat units stacked along the axial direction result in a plurality of the COx electrolyzer cells stacked along the axial direction and positioned between the first end assembly and the second end assembly;
• the cathode interface assembly comprising:
• an instance of the components of the cathode side of one of the plurality of repeat units;
• one of the MEAs;
• a cathode interface separator plate interposed between the first end plate and an immediately adjacent one of the plurality of repeat units such that a first end cell is formed between the cathode interface assembly and the immediately adjacent one of the plurality of repeat units;
• wherein each of the separator plates comprises:
• a plurality of fastener orifices through which the frame fasteners respectively extend;
• at least one first hole through which an inlet anolyte flow path extends;
• at least one second hole through which an outlet anolyte flow path extends;
• at least one third hole through which an inlet gaseous COx flow path extends;
• and
• at least one fourth hole through which an outlet COx reduction byproduct flow path extends;
• the first end assembly further comprises a first insulation plate, a manifold, and a first bus plate between the first end plate and the cathode interface assembly;
• the manifold comprising:
• at least one first inlet fluidically connected to the anode sides of the plurality of COx electrolyzer cells via the inlet anolyte flow path;
• at least one first outlet fluidically connected to the anode sides of the plurality of COx electrolyzer cells via the outlet anolyte flow path;
• at least one second inlet fluidically connected to the cathode sides of the plurality of COx electrolyzer cells via the inlet gaseous COx flow path;
• and
• at least one second outlet fluidically connected to the cathode sides of the plurality of COx electrolyzer cells via the outlet COx reduction byproduct flow path;
• the first bus plate is configured to receive a first electric potential;
• and
• the first insulation plate is configured to electrically insulate the first end plate from the first bus plate, the inlet anolyte flow path, the outlet anolyte flow path, the inlet gaseous COx flow path, and the outlet COx reduction byproduct flow path do not extend into the first bus plate and the first insulation plate.