MULTI-CELL COx ELECTROLYZER STACKS
Various CO x electrolyzer multi-cell architectures are provided, including various frame, flow field, gas diffusion layer, and repeat unit designs that may be particularly useful in the context of multi-cell CO x electrolyzer cells.
1 . A COx electrolyzer apparatus (“apparatus”) comprising:
a first end assembly;
a second end assembly coupled to the first end assembly via a plurality of tensioning members; and
a plurality of COx electrolyzer cells (“cells”) interposed between the first and second end assemblies and arranged in a stack along an axial direction, wherein each of the plurality of cells comprises:
a cathode frame that defines a first opening;
a cathode flow field at least partially disposed in the first opening;
an anode frame that defines a second opening;
an anode flow field at least partially disposed in the second opening;
a first support frame;
a second support frame; and
a membrane electrode assembly (MEA) sandwiched between the first support frame and the second support frame, wherein the MEA is positioned between the cathode flow field and the anode flow field.
2 . The apparatus of claim 1 , further comprising:
a cathode gas diffusion layer (GDL) that is positioned between the MEA and the cathode flow field.
3 . The apparatus of claim 2 , wherein the cathode GDL is positioned between the first and second support frames such that one of the first and second support frames directly contacts the MEA, the other of the first and second support frames directly contacts the cathode GDL, and the MEA and the cathode GDL are both sandwiched between the first support frame and the second support frame.
4 . The apparatus of claim 1 , further comprising:
a cathode gasket that is interposed between the cathode frame and the first support frame such that a first side of the cathode gasket abuts a face of the cathode frame and a second side of the cathode gasket abuts a face of the first support frame.
5 . The apparatus of claim 4 , wherein the cathode gasket encircles the cathode flow field.
6 . The apparatus of claim 1 , further comprising:
one or more separator plates, wherein one of the one or more separator plates is positioned between adjacent cells of the plurality of cells.
7 . The apparatus of claim 1 , wherein the MEA comprises an anion-conducting polymer.
8 . The apparatus of claim 1 , wherein the cathode flow field receives gaseous carbon oxide and distributes the gaseous carbon oxide across a surface of the MEA.
9 . The apparatus of claim 1 , further comprising:
an anode porous transport layer (PTL) positioned between the anode flow field and the MEA.
10 . The apparatus of claim 1 , wherein the MEA comprises:
a cathode layer comprising an anion-conducting polymer;
an anode layer; and
an ion-conducting polymer layer positioned between the anode layer and the cathode layer.
11 . The apparatus of claim 1 , wherein the first support frame, the second support frame, and the MEA form a unitized MEA assembly.
12 . The apparatus of claim 11 , further comprising a cathode annular insert at least partially supported in at least one opening in the cathode frame and encircling the cathode flow field, wherein the cathode annular insert abuts against a corresponding surface of the cathode frame and abuts against one or more corresponding surfaces of the unitized MEA assembly.
13 . The apparatus of claim 1 , wherein the first support frame includes a bulged portion partially defining a cavity that is configured to receive a portion of the MEA.
14 . The apparatus of claim 13 , further comprising:
a cathode gas diffusion layer (GDL) that is positioned between the MEA and the cathode flow field, wherein a portion of the cathode GDL is positioned in the cavity.
15 . The apparatus of claim 1 , wherein one or both of the first support frame and the second support frame include a protruded tab portion.
16 . The apparatus of claim 1 , wherein:
the first end assembly further comprises a first insulation plate and a first bus plate, and
an inlet anolyte flow path, an outlet anolyte flow path, an inlet gaseous COx flow path, and an outlet COx reduction byproduct flow path do not extend into the first bus plate and the first insulation plate.
17 . The apparatus of claim 1 , wherein:
the second end assembly further comprises a second bus plate, a bladder gasket, and a first recess formed in a central portion of the second insulation plate, and
the second bus plate is slidably disposed in the first recess and configured to abut against the bladder gasket and/or a surface of the first recess facing the second bus plate in the axial direction.
18 . The apparatus of claim 10 , wherein the anode layer comprises an oxidation catalyst.
19 . The apparatus of claim 10 , wherein the anode layer comprises a cation-conducting polymer.
20 . The apparatus of claim 10 , wherein the cathode layer further comprises a reduction catalyst.