Abstract
The present disclosure provides approaches for increasing the adhesion of a catalyst ink on a substrate, use of binders within an electrode ink to enhance coating uniformity, incorporating pore-forming agents within an electrode ink, approaches for growing an electrode on a reinforcement layer, increasing the electrochemically active surface area, and incorporation of certain materials in an electrode ink. The present disclosure also relates to electrodes for electrochemical cells, including area-scalable electrodes designed for high-speed manufacturing. The materials, devices and methods described herein may apply to either one or both of an anode or a cathode electrode for an electrochemical cell.
Claims
1. A method of increasing the effective electrochemically active surface area of a substrate, comprising: (a) alloying a substrate with an alloy material, wherein the alloy material is incorporated into the surface of the substrate, subsequently de-alloying the substrate to remove the alloy material; or (b) deposition or electrodeposition of a material onto a substrate, such that the added material creates a higher surface roughness.
2. The method of claim 1, wherein the substrate is porous.
3. The method of claim 1, wherein after (b), further comprising applying heat treatment to induce alloying of the material and subsequently de-alloying the substrate to remove the alloy material.
4. The method of claim 1, further comprising depositing or electrodepositing an additional catalytic material onto the substrate.
5. The method of claim 1, further comprising introducing an ionic material in a working fluid that deposits on the electrochemically active surface area and increases the catalytic activity of the surface.
6. A method for increasing adhesion of a catalyst ink on a substrate, comprising: treating the substrate with an adhesion promoter, wherein the adhesion promoters is selected from the group consisting of (a) self-assembled monolayers of aliphatic phosphonic acid, silane, alkyl thiols, or similar materials, (b) conductive adhesives such as Electrodag: Bonderite S-FN EB 012 Acheson, or similar materials, and (c) mixtures thereof.
7. The method of claim 6, further comprising modifying the surface roughness of the substrate, wherein the surface roughness is modified by treating the surface with agents that alter the surface tension, such as surfactants, including 3M Fluorosurfactant FC-4430, or similar materials.
8. The method of claim 6, wherein the substrate is an electrode.
9. An electrode ink for coating an electrode, comprising: a binder or a pore forming agent.
10. The electrode ink of claim 9, wherein the binder is selected from the group consisting of PTFE, PVA, PAA, PVDF, SBR, SEBS, and similar materials.
11. The electrode ink of claim 10, wherein the binder is an ionic polymeric binder containing cationic protons or anionic hydroxide ions.
12. The electrode ink of claim 9, further comprising a surface tension altering agent, wherein the surface tension altering agent is selected from the group consisting of surfactants, fluoro surfactants, silicone surfactants, siloxane, and similar materials.
13. The electrode ink of claim 9, further comprising quaternized poly-vinyl alcohol.
14. The electrode ink of claim 9, wherein the pore forming agent is selected from the group consisting of an ammonium bicarbonate, ammonium carbonate, sodium carbonate, sodium bicarbonate, similar materials, and mixtures thereof.
15. The electrode ink of claim 9, wherein the pore forming agent is a leavening agents, wherein the leavening agent is selected from the group consisting of air, steam, yeast, baking soda, baking powder, similar materials, and mixtures thereof.
16. A method of producing an electrode, comprising: growing the electrode on a reinforcement layer via hydrothermal deposition, electrodeposition, room condition deposition, or a similar process.
17. The method of claim 16, wherein the electrode comprises platinum, molybdenum, nickel, cobalt, boron, cerium, iron, tin, sulfur, phosphorus, fluorine, oxygen, hydroxide, similar materials, or mixtures thereof.
18. The method of claim 16, wherein the electrode is supported on a conductive support, wherein the conductive support comprises such as carbon (Vulcan, Ketjen black, etc.), nickel, iron, titanium, stainless steel, or combinations of these materials.
19. The method of claim 16, wherein the electrode comprises a nickel iron oxide (NiFe.sub.2O.sub.4), wherein the reinforcement layer comprises a nickel foam or nickel felt.
20. The method of claim 16, wherein the electrode comprises Pt and carbon, wherein the reinforcement layer comprises a nickel foam, nickel felt, or a carbon fiber reinforcement layer.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0035] The accompanying drawings are incorporated into and constitute a part of this specification. The drawings illustrate certain embodiments only of the present disclosure and, together with the foregoing and following descriptions, explain the principles of the disclosure. Wherever possible the same identification numbers have been used to indicate common or like components across different figures.
[0036] FIG. 1 shows an isometric view of electrolysis cell components of FIG. 3 illustrating exemplary cross flow orientation of the process fluids along x- and y-axes and the repeating of cell components along a z-axis to create a stack of cells.
[0037] FIG. 2 shows a cross-section of electrolysis cell components in the active area of a typical cell illustrating ion, electron and fluid flows for proton and anion exchange membrane electrolysis technologies.
[0038] FIG. 3 shows an isometric view of an anode flow field component illustrating trade-offs present in scaling the cell active area.
[0039] FIG. 4 shows mathematical model output for pressure loss through an exemplary flow field for water and hydrogen flow versus velocity and an illustrative pressure loss target threshold.
[0040] FIG. 5 shows test results for water flow resistance for a variety of flow field candidates, confirming the model results of FIG. 4 for water flow pressure loss and illustrating alternate illustrative pressure loss target thresholds.
[0041] FIG. 6 shows mathematical model output for water temperature rise versus water stoich value for two exemplary cell operating voltage values and an illustrative water temperature rise threshold.
[0042] FIG. 7 shows mathematical model output for oxygen volume fraction at the outlet versus water stoich value for an exemplary cell operating pressure and an illustrative oxygen volume fraction threshold.
[0043] FIG. 8 shows multiple test results for mechanical strength of a candidate flow field, illustrating the percentage of initial thickness the material must be calendered to in order to withstand a target compressive loading when assembled into a complete cell/stack.
[0044] FIG. 9 shows the basic steps that may be included in a high-speed manufacturing process for creating a scalable, reinforced electrode and an integrated electrode flow field component.
[0045] FIG. 10 shows a plan view of the process of FIG. 9 illustrating the inherent y-axis scalability (I) of the reinforced electrode and flow field component manufacturing processes from a fixed, x-axis roll web width (w) to achieve cells of variable active area.
[0046] FIG. 11 shows some illustrative examples of embossing or patterning of surfaces of an electrode and/or flow field substrate to promote bonding during lamination.
[0047] FIG. 12 shows a representative scanning electron microscope image of an anode electrode synthesized using pore forming agents presently disclosed.
[0048] FIG. 13 shows measured performance data over time for a preferred embodiment of the present invention illustrating superior lifetime compared to prior art.
DETAILED DESCRIPTION OF DRAWINGS
[0049] Detailed descriptions of the figures of drawing will now be given with reference to the accompanying drawings. Although the following descriptions relate primarily to electrolysis, it is understood that the described features, components, and methods are applicable and adaptable, by those skilled in the art, to other electrochemical technologies including hydrogen compressors, hydrogen purifiers, CO.sub.2 electrolyzers, chlorine electrolyzers, etc. One of ordinary skill would understand the subject matter described in the foregoing embodiments (relating to, e.g., approaches for increasing the adhesion of a catalyst ink on a substrate, use of binders within an electrode ink to enhance coating uniformity, incorporating pore-forming agents within an electrode ink, approaches for growing an electrode on a reinforcement layer, increasing the electrochemically active surface area, and incorporation of certain materials in an electrode ink) may be applied to the embodiments set forth in the figures of drawing.
[0050] FIG. 1 shows an isometric view (101) of an electrolyzer illustrating exemplary cross flow orientation (103) and (104) of the process fluids and the repeating of cell components (105) along a z-axis (102) to create a stack of cells. Here, the bipolar plate (106) can be seen separating one cell of thickness (107) from an adjacent cell (105). Water and oxygen (103) may flow along an x-axis in the combined anode electrode flow field (111) of thickness (108). Hydrogen (104) may flow along a y-axis in the combined cathode electrode flow field (109) of thickness (110). Assuming the cell is oriented as shown with a gravity vector downward and parallel to the z-axis, it may be advantageous to position the anode above the membrane as shown to allow buoyancy to assist in moving oxygen bubbles that form on the anode electrode into the water flowing through the anode flow field above the anode electrode.
[0051] FIG. 2 shows a cross-section of exemplary core electrolysis cell components (201) in the active area of a cell, illustrating typical ion, electron, and fluid flows for proton (212) and anion (213) exchange membrane electrolysis technologies. Here (208) is an impermeable separator, or bipolar, plate; (205) is a cathode flow field; (207) is a cathode electrode; (204) is an ion-conducting membrane; (206) is an anode electrode and (203) is an anode flow field. Attaching a power supply to the cell with a negative pole (209) at the bottom and a positive pole (210) at the top, may cause electrons (211) to flow upward through the cell. If the cell is an acidic, proton-conducting type (212), positive hydronium ions may be motivated by the resulting electrical field to move downward through the membrane (204). If the cell is an alkaline, hydroxide-conducting type (213), negative hydroxide ions may be motivated by the resulting electrical field to move upward through the membrane (204). In both types, hydrogen may be formed on the cathode (207) and flow into the cathode flow field (205), whereas oxygen may be formed on the anode (206) and flow into the anode flow field (203). In dry-cathode systems, water may be provided only to the anode flow field (203) as a reactant for forming hydrogen and oxygen. Stoichiometry is a term relating to the balance of a chemical reaction. In electrochemical cells, the term stoichiometry or stoich refers to the ratio of reactants fed to a cell relative to the amount required to exactly balance the overall reaction. As described earlier in this specification, the water stoich provided to anode flow field (203) may be much higher than 1. Also, because the fluid in the anode flow field (203) may be mostly liquid, this compartment may represent significant flow resistance compared to the cathode flow field. The thickness of the cathode (214) and anode (215) flow fields may have an impact on flow velocity, temperature distribution and pressure losses in the cell. The overall cell pitch (216) of the cell may be determined by the thicknesses of each of components (203) through (208) making up the complete cell. A small cell pitch (216) may be desirable for producing an electrolyzer stack with high power density and a small size for a given hydrogen production rate [kg/hr]. Therefore, optimizing the anode flow field geometrylength in a water flow direction along an x-axis, width along a y-axis and thickness along a z-axismay be a critical design goal for an electrolyzer. For example, anode (203) and/or cathode (205) flow fields may be configured with thicknesses of 0.1 to 5.0 mm, 0.2 to 3.0 mm, 0.3 to 2 mm, 0.5 to 2 mm or 0.6 to 2 mm. Flow fields (203) and (205) may be selected with the same or different thicknesses based on factors for optimizing cell process conditions, performance and manufacturing.
[0052] FIG. 3 shows an isometric view (301) of an anode electrode flow field component (306) illustrating the trade-offs that may be present in scaling the cell area. An anode flow field may comprise a width w (305) along an x-axis, a length I (304) along a y-axis and a thickness t (303) along a z-axis. A width w (305) along an x-axis may be between 5 and 1000 cm, between 5 and 500 cm, between 5 and 100 cm, or between 10 and 50 cm. A length I (304) along a y-axis may be between 1 and 5000 cm, between 5 and 3000 cm, between 10 and 1000 cm or between 25 and 1000 cm. The active area (307) may be found by multiplying the width w (305) by the length I (304). A water flow area at a leading edge (308) may be found by multiplying the thickness t (303) by the length I (304). A water flow for a fixed stoich and efficiency (309) into this water flow area (308) may be determined by the area (307). To achieve higher hydrogen production [kg/hr] at a fixed efficiency and water stoich may require added area dA (311a) and/or (311b). If dA (311b) is made by adding dw (310b) to w (305), added water (313b) may be required to flow into the fixed leading edge flow area (308). The added water flow may thereby increase water flow velocity through the flow field and may result in increased pressure drop (314). If dA (311a) is made by adding dl (310a) to I (304), added water (313a) may be accompanied by a proportional increase in fixed leading edge flow area (312a). The added water may flow through the incremental and proportional flow area (312a) without increasing pressure drop (314). Therefore, scaling area along a y-axis may allow all process conditions-pressures, temperatures, and oxygen volume fraction-within the electrode to remain constant. While total water flow rate may necessarily be proportional to hydrogen/oxygen production rate, other system parameters may be unchanged by scaling the electrode along only a y-axis. This may greatly simplify the resulting electrolyzer systems made from electrodes designed in this way. For example, electrolyzer production plant specifications including pressure ratings, temperature ratings, and/or fluid composition ratings may be consistent for plants of different water flow and hydrogen/oxygen capacities. This, in turn may simplify engineering procurement and construction activities, expand available supplies of system components, and reduce overall hydrogen production costs.
[0053] FIG. 4 shows mathematical model results (431) for pressure loss per unit flow length (414) [mbar/cm] as a function of flow velocity (409) [cm/s] for a hydrogen gas (432) and a liquid water (433) flowing through a typical porous media that may be used for an anode and/or cathode flow field. Also shown is an illustrative target pressure loss threshold (434) that may selected based on the overall electrolyzer stack and system design. Threshold (434) may represent an upper limit for water pressure loss and thereby define a target threshold for water velocity in the anode flow field (435). As evident from results (431), pressure loss per unit length for hydrogen may be several times less than for water at a given velocity. It may, therefore, be advantageous to prioritize electrode scaling based on water velocity and flow length as cell area increases. For example, water pumps for delivering water to an electrolysis cell may have pressure capability of up to 10 bar. It may be advantageous to configure anode flow field (401) to enable water velocity (409) below 100 cm/s, below 50 cm/s, below 20 cm/s, below 10 cm/s or below 5 cm/s to stay within the capabilities of commonly available system water pumps.
[0054] FIG. 5 shows test results (561) for pressure loss per unit flow length (514) [mbar/cm] as a function of flow velocity (509) [cm/s] for liquid water flowing through a number of porous media candidates that may be used for an anode and/or cathode flow field. The mathematical model results from FIG. 4 (533) are repeated for reference along with an illustrative target pressure loss threshold (534) that may selected based on the overall electrolyzer stack and system design. Threshold (534) may represent an upper limit for water pressure loss and thereby define a target threshold for water velocity in the anode flow field (535) for these real potential flow field candidates (samples 1 through 8).
[0055] FIG. 6 shows mathematical model results (641) for water temperature rise (615) [ C.] as a function of delivered water stoich value. Heat released during electrolyzer operation may be a function of efficiency, which in turn, may be a function of operating cell voltage. Conserving energy for a cell may result in a formula for water temperature rise as specified in equation 6c-1 (below). Here V is the cell voltage, V.sub.0 is the thermo-neutral cell voltage [1.25V], LHV is the lower heating value of hydrogen [120 MJ/kg], c.sub.p is the specific heat capacity of water [4.182 KJ/kg C.] and St is the water stoich delivered to the cell. Plots (642) and (643) show results of this model at two possible operating voltages representing exemplary values for beginning [BoL] and end [EoL] of life for an electrolysis cell. Also shown is an illustrative water temperature rise target threshold (644), above which an anode electrode may not operate stably or durably or above which an electrolysis cell, stack or system may not operate efficiently. The temperature rise threshold may be used with an EoL voltage limit to define a lower threshold for water stoich (645). It may be advantageous to select a water stoich to maintain a water temperature rise at end of life below 100 C, below 50 C, below 25 C, below 15 C or below 10 C to maintain stable and durable operation of the electrode.
[00001]
[0056] FIG. 7 shows mathematical model results (751) for oxygen volume fraction at the anode flow field outlet (752) as a function of delivered water stoich value. The process of electrolysis splits water into hydrogen, on the cathode side, and oxygen, on the anode side. As oxygen forms on the anode, it may mix as a gas with the delivered liquid water, resulting in a two-phase flow in the anode flow field. The volume fraction of oxygen at the anode outlet may be indicative of operating stability, performance and/or durability of the electrode and a target threshold for this parameter may be set by a designer. Conserving mass for a cell may result in a formula for oxygen outlet volume fraction as specified in equation 7d-1. Here .sub.O2 is the density of the oxygen gas at the anode outlet, .sub.H2O is the density of the liquid water at the anode outlet and St is the water stoich delivered to the cell. Plot (752) shows the results of this model at 10 bara pressure for an anode electrode along with an illustrative oxygen volume fraction threshold (754), above which the electrode may not operate stably or durably or above which an electrolysis cell, stack or system may not operate efficiently. The oxygen volume fraction threshold may be used to specify a lower threshold for water stoich (755). It may be advantageous to select a water stoich to maintain an oxygen volume fraction below 80%, below 60%, below 50%, below 40% or below 30% in order to maintain stable and durable operation of the electrode.
[00002]
[0057] FIG. 8 shows measured strength data (861) for several samples of candidate electrode reinforcement materials illustrating the permanent change in thickness (809) as a function of the mechanical exposure stress (814). This curve then represents the material yield strength as a function of deformed thickness. During assembly of the electrolysis stack, compressive load will be applied to the active area in order to maintain adequate contact and low contact resistance between the layers in a cell and between individual cells in the stack. The applied compressive load at assembly may be greater than the expected internal fluid pressure of the stack to ensure that cells or cell components do not separate during operation. It is desirable to maintain elastic behavior of the cells and cell components to ensure this contact is maintained. As illustrated by limits (834) and (835), it may then be advantageous to permanently deform the electrode reinforcement materials to a value less than X % of their initial thickness to ensure the electrode reinforcement remains elastic. For the candidate materials tested X=40%, but the specific value for any candidate electrode reinforcement material may be greater or less than 40% based on the particular characteristics and material properties of the candidate including porosity, basis weightdefined as the mass per unit area in an x-y planematerial of construction, and porous geometry (e.g. foam, mesh, expanded metal, felt or other).
[0058] FIG. 9 shows the basic steps in a high-speed manufacturing process (901) for creating an reinforced electrode and flow field component (913). One or more rolls of porous substrate (903a) may be selected based on a desired roll web width w (915) as previously described. The substrate may comprise a foam, a felt, a woven screen, an expanded metal, a sintered frit or a fiber cloth or paper. The selected substrate may have a porosity of up to 98% where porosity is defined as the volume percent of the substrate available to through-flow of fluid. For example, the porosity may be between 98% and 40%, between 95% and 50%, between 90% and 60%, or between 95% and 80%. The composition of the substrate may comprise iron, nickel, chromium, steel, stainless steel, Inconel, aluminum, titanium, carbon, or combinations of these. The substrate may be plated or coated with other materials such as platinum, gold, tin, carbon, titanium nitride, PTFE or another corrosion-inhibiting layer including engineered layers of polymeric or oxide materials with conductive metal or carbon pathways. The roll(s) (903a) may be loaded onto an unwinding station designed to hold the web flat, under a known tension and able to move along a y-axis (902). The roll(s) (903a) may be calendered through a set of rollers (904) and (905) to laminate more than one layer together, reduce the porosity of the web, reduce or increase its thickness, increase its strength, increase its stiffness, and/or create desired surface characteristics on one or both sides of the web (906). For example, it may be advantageous for the substrate to be relatively smooth on one side and rough on the other to facilitate steps later in the process. It may also be advantageous to achieve a porosity gradient through the thickness of the substrate. For example, it may be beneficial to downstream processes to have one side of calendered substrate (906) be relatively low porosity for accepting a conversion to an electrode while having the opposite side of (906) be relatively high porosity to promote bonding with a second substrate. To achieve different propertied on each side of web (906), the rollers (904) and (905) may be the same or different diameter and/or be made of the same or different materials and/or be constructed with different surface finishes or coatings and/or be provided with specific surface patterns that may be embossed onto one or both sides of roll web (903a). The calendered, reinforcement substrate (906) may then be converted to an electrode (908) in process (907) as set forth in the embodiments described in the present disclosure. For example, an electrode material may be spray coated, screen printed, rotary screen printed, doctor-blade coated, slot-die coated, curtain coated, squeegee coated or laminated as a film, decal or solid layer using heat and/or pressure on the appropriate surface of the electrode substrate (906). The electrode conversion process (907) may also comprise a post-coating step. For example, the coating may be dried, heat treated, annealed and/or otherwise physically or chemically treated to promote bonding to the substrate and/or electrochemical performance of the cell. The conversion process (907) may also comprise a chemical or physical vapor deposition process for conversion to an active electrode (908). The conversion process (907) may also comprise a plasma or flame spray process for depositing electrode material onto the substrate (906) or for chemically reacting and/or converting (906) into an active electrode. Following process (907), electrode web (908) may be placed adjacent to one or more additional rolls of porous substrate (903b). These substrates may be identical to or different from electrode substrates (903a) and may be selected based on a similar range of possible materials and propertied as (903a), but toward meeting functional requirements for a fluid flow field, rather than an electrode reinforcement. For example, it may result in the highest purchase volume and lowest supply cost to make (903b) identical to (903a). It may be advantageous for cell performanceelectrical resistance, flow resistance, thermal conductivity, mechanical resiliency, or mechanical strengthto select (903b) from a different substrate than (903a). In process step (910) the electrode web (908) may be laminated to flow field web (909) through an appropriate lamination process. The lamination process (910) may comprise mechanical rolling or calendering through rollers similar to (904) and (905) in order to promote co-penetration of solid fibers, ligaments or wires from web (908) with web (909). To accomplish this mechanical bonding, the similar rollers (904) and (905) may be the same or different diameter and/or be made of the same or different materials and/or be constructed with different surface finishes or coatings and/or be provided with specific surface patterns. It may be advantageous to select (903a) and (903b) from the same supplied material, but to pre-calender and/or laminate multiple layers of (903b) before lamination step (910). The pre-calendering/laminating step may include embossing a pattern into the side of (909) to be co-penetrated with (908) to promote mechanical bonding. The laminating process (910) may also comprise other steps including heat treatment or application of bonding promoters such as adhesives, polymer suspensions, liquid ionomers, or ionomer suspensions to one or more of the webs (908) and (909). The order of steps (907) and (910) may be reversed so that conversion of web (906) to electrode (908) may take place after laminating to web (909). It may be advantageous for certain electrode materials and/or methods to be formed only after calendering and laminating to ensure adequate adhesion is maintained in the final web (911). In some cases, the electrode may be coated onto the membrane, in which case the conversion step (907) may be skipped in process (901). Following lamination step (910), the unitized electrode flow field web (911) may be processed (912) to create discreet piece parts (913) of the appropriate size for integration into an electrolysis cell (915). For example, the web (911) may be processed in step (912) by stamping with a knife or other cutting die to ensure precise sizing of the piece parts. In some cases, laminating web (908) to web (909) may take place after cutting step (912). The exact size of parts (913) may depend on whether an anode or a cathode electrode flow field is to be produced. The overall process (901) may be adapted as necessary to produce either anode or cathode electrode/flow fields and specific materials, coatings, steps, and settings of the line may be the same or different for each. In production, two independent lines may be employed to simultaneously produce one anode and one cathode electrode/flow field to enable high-speed manufacturing of complete electrolysis cells.
[0059] FIG. 10 shows a plan view (x-y plane) of the process described in FIG. 9. Descriptive labels have been kept the same between the figures. The area-scalability of the present invention is illustrated by variable length die cut steps (912) resulting in variable area electrode piece parts (913) by changing only the length (1009) of the parts. Process (901) has the advantage of requiring capital equipment of a fixed roll handling width (915) to produce electrodes of varying active area while achieving consistent operating conditions for the various size electrodes, as described in FIGS. 3 through 7.
[0060] FIG. 11 shows several illustrative examples of patterning or embossing of an electrode and/or flow field substrate to promote enhanced bonding during lamination steps of process (901). Patterns may be linear, along a y-axis as shown in (1121) and (1122), along an x-axis (not shown) or along both x- and y-axes in a crosshatch style (1123) and (1124). The profile shapetriangle (1121), rectangle (1122) or other shapes (not shown)depth and spacing may be optimized based on the material and other properties of the substrates to be laminated.
[0061] FIG. 12 shows an electron scanning microscope image taken of an electrode synthesized per a preferred embodiment of the present invention using a bicarbonate pore forming agent illustrating the resulting macro- and micro-porosity of the electrode structure.
[0062] FIG. 13 shows performance data (1301) of cell voltage (1304) as a function of operating time (1305) measured on a cell operating at 0.5 A/cm.sup.2 and 60 C., with a NiFe.sub.2O.sub.4 anode electrode synthesized and fabricated on a nickel foam reinforcement layer per a preferred embodiment of the present invention. The data illustrate over 330 hours of durable operation without catalyst detachment or washout. For comparison, public data (1302) [ACS Appl. Mater. Interfaces 2021, 13, 44, 51917-51924, https://pubs.acs.org/doi/10.1021/acsami.1c06053] is overlayed, illustrating greater decay rate and inferior lifetime for 3 competitive systems (1303) at comparable operating conditions as compared to the present invention (1301).
Further Embodiments
[0063] A-1. An electrode for an electrochemical cell, comprising: [0064] an active electrode material, [0065] a reinforcement substrate, and [0066] a flow field, [0067] wherein the open flow field comprises a first layer comprising a material selected from the group consisting of a foam, a felt, a woven screen, an expanded metal, and a sintered metal frit of a desired roll web width along an x-axis, [0068] wherein the reinforcement substrate comprises a second layer comprising a material selected from the group consisting of a foam, a felt, a woven screen, an expanded metal, and a sintered metal frit of a desired roll web width along an x-axis, [0069] wherein a thickness of the flow field along a z-axis and a length of the flow field along a y-axis are independently adjustable to produce a variable cell active area that maintains a water flow resistance, a water temperature rise, or a cell outlet oxygen volume fraction below a target threshold for the electrode. [0070] A-2. The electrode of A-1, [0071] wherein the thickness and length are selected to achieve a water flow velocity less than 100 cm/s at a leading edge of the flow field or wherein the thickness and length are selected to achieve a water flow pressure drop less than 5 bar between a leading edge and a training edge of the flow field when operated at rated conditions and hydrogen production capacity. [0072] A-3. The electrode of A-1 to A-2, [0073] wherein the open flow field comprises a multilayer laminate. [0074] A-4. The electrode of A-1 to A-3, [0075] wherein a thickness of the combined reinforced electrode and flow field is less than 3 mm, preferably 2 mm, most preferably 1 mm. [0076] A-5. The electrode of claim A-1 to A-4, [0077] wherein a water temperature rise is less than 50 C. [0078] A-6. The electrode of claim A-1 to A-5, [0079] wherein the outlet oxygen volume fraction is less than 95%. [0080] A-7. The electrode of A-1 to A-6, [0081] wherein the active electrode material is bonded to the reinforcement substrate an adhesion promoter selected from the group consisting of an adhesive, a polymer dispersion, a liquid ionomer, an ionomer dispersion, and mixtures thereof. [0082] A-8. The electrode of A-1 to A-7, [0083] wherein the bonding promoter is PTFE incorporated into the electrode ink during synthesis. [0084] A-9. The electrode of A-1 to A-8, [0085] wherein the active electrode material contains a forming agent selected from the group consisting of ammonium bicarbonate, ammonium carbonate, sodium carbonate, sodium bicarbonate, air, steam, yeast, baking soda, baking powder, and mixtures thereof. [0086] A-10. The electrode of A-1 to A-9, [0087] wherein the active electrode material and the flow field comprise at least one of carbon, nickel, titanium, iron, chromium, stainless steel, or Inconel. [0088] A-11. The electrode of A-1 to A-10, [0089] wherein the electrode reinforcement substrate and the flow field comprise one or more nickel foam layers. [0090] A-12. The electrode of A-1 to A-11, [0091] wherein a porosity, basis weight, number of layers, and final laminated thickness of the flow field are selected to prevent yielding during assembly, compression, and operation of the cell. [0092] A-13. The electrode of claim A-1 to A-12, [0093] wherein the yield strength achieved is greater than 5 kgf/cm.sup.2, preferably 10 kgf/cm.sup.2, more preferably 15 kgf/cm.sup.2, and most preferably 25 kgf/cm.sup.2. [0094] A-14. The electrode of claim A-1 to A-13, [0095] wherein one or more of the electrode reinforcement substrate and flow field substrate comprises a rough, patterned, or embossed surface to promote lamination. [0096] B-1. A method of manufacturing an integrated electrode flow field for a scalable electrolysis cell comprising: [0097] forming an open flow field through lamination or calendering to a desired thickness along a z-axis one or more layers selected from the group consisting of a foam, a felt, a woven screen, an expanded metal, and a sintered metal frit of a desired roll web width along an x-axis; [0098] cutting the open flow field web into discrete pieces corresponding to a desired length along a y-axis; [0099] forming an electrode reinforcement substrate through lamination and/or calendering to a desired thickness along a z-axis one or more layers selected from the group consisting of a foam, a felt, a woven screen, an expanded metal, and a sintered metal frit of a desired roll web width along an x-axis; [0100] converting the formed electrode reinforcement substrate to an active, reinforced electrode; [0101] cutting the active reinforced electrode web into discrete pieces of a desired length along a y-axis; and [0102] placing the open flow field and active, reinforced electrode components adjacent to each other such that the resulting assembly achieves a desired cell active area while maintaining one or more of a water flow resistance or a water temperature rise or a cell outlet oxygen volume fraction below a target threshold for the electrode. [0103] B-2. The method of B-1, [0104] wherein the thickness and length are selected to achieve a water flow velocity less than 100 cm/s at the leading edge of the flow field. [0105] B-3. The method of B-1 to B-2, [0106] wherein the thickness and length are selected to achieve a water flow pressure drop less than 5 bar between the leading and training edges of the electrode flow field when operated at rated conditions and hydrogen production capacity. [0107] B-4. The method of B-1 to B-3, [0108] wherein a thickness of the combined reinforced electrode and flow field is less than 3 mm, preferably 2 mm, most preferably 1 mm. [0109] B-5. The method of B-1 to B-4, [0110] wherein the water temperature rise is less than 50 C. [0111] B-6. The method of B-1 to B-5, [0112] wherein the outlet oxygen volume fraction is less than 95%. [0113] B-7. The method of B-1 to B-6, [0114] wherein the flow field web and reinforced electrode web are laminated prior to cutting into discrete piece parts. [0115] B-8. The method of B-1 to B-7, [0116] wherein electrode and flow field substrates comprise at least one of carbon, nickel, titanium, iron, chromium, stainless steel or Inconel. [0117] B-9. The method of B-1 to B-8, [0118] wherein one or more of the reinforced electrode web and flow field web is processed to produce a rough, patterned, or embossed surface to promote lamination. [0119] B-10. The method of B-1 to B-9, [0120] wherein the laminating step includes a bonding promoter selected from the group consisting of an adhesive, a polymer dispersion, a liquid ionomer, and an ionomer dispersion. [0121] B-11. The method of B-1 to B-10, [0122] wherein the electrode reinforcement substrate comprises one or more nickel foam layers having a basis weight between 100 g/m.sup.2 and 1000 g/m.sup.2. [0123] B-12. The method of B-1 to B-11, [0124] wherein the electrode conversion of the electrode reinforcement substrate occurs before lamination to the flow field web. [0125] B-13. The method of B-1 to B-12, [0126] wherein the electrode conversion of the electrode reinforcement substrate occurs after lamination to the flow field web. [0127] B-14. The method of B-1 to B-13, [0128] wherein the reinforced electrode and flow field are laminated upon assembly within the electrolysis cell. [0129] B-15. The method of B-1 to B-14, [0130] wherein a porosity, basis weight, number of layers and final laminated thickness of the flow field are selected to prevent yielding during assembly, compression, and operation of the cell. [0131] B-16. The method of B-1 to B-15, [0132] wherein the yield strength is greater than 5 kgf/cm.sup.2, preferably 10 kgf/cm.sup.2, more preferably 15 kgf/cm.sup.2, most preferably 25 kgf/cm.sup.2. [0133] C-1. A method of increasing the effective electrochemically active surface area of a substrate, comprising [0134] alloying a substrate with an alloy material, wherein the alloy material is incorporated into the surface of the substrate, [0135] subsequently de-alloying the substrate to remove the alloy material; or [0136] C-2. The method of C-1, [0137] wherein the substrate is porous. [0138] C-3. A method of increasing the effective electrochemically active surface area of a substrate, comprising [0139] deposition or electrodeposition of a material onto a substrate, such that the added material creates a higher surface roughness. [0140] C-4. The method of C-3, [0141] further comprising applying heat treatment to induce alloying of the material and subsequently de-alloying the substrate to remove the alloy material. [0142] C-5. The method of C-1 to C-4, [0143] further comprising depositing or electrodepositing an additional catalytic material onto the substrate. [0144] C-6. The method of C-1 to C-5, [0145] further comprising introducing an ionic material in a working fluid that deposits on the electrochemically active surface area and increases the catalytic activity of the surface. [0146] D-1. A method for increasing adhesion of a catalyst ink on a substrate, comprising: [0147] treating the substrate with an adhesion promoter, wherein the adhesion promoters is selected from the group consisting of (a) self-assembled monolayers of aliphatic phosphonic acid, silane, alkyl thiols, or similar materials, (b) conductive adhesives such as Electrodag: Bonderite S-FN EB 012 Acheson, or similar materials, and (c) mixtures thereof. [0148] D-2. The method of D-1, [0149] further comprising modifying the surface roughness of the substrate, wherein the surface roughness is modified by treating the surface with agents that alter the surface tension, such as surfactants, including 3M Fluorosurfactant FC-4430, or similar materials. [0150] D-3. The method of D-1 to D-2, [0151] wherein the substrate is an electrode. [0152] E-1. An electrode ink for coating an electrode, comprising: [0153] a binder or a pore forming agent. [0154] E-2. The electrode ink of E-1, [0155] wherein the binder is selected from the group consisting of PTFE, PVA, PAA, PVDF, SBR, SEBS, and similar materials. [0156] E-3. The electrode ink of E-1 to E-2, [0157] wherein the binder is an ionic polymeric binder containing cationic protons or anionic hydroxide ions. [0158] E-4. The electrode ink of E-1 to E-3, [0159] further comprising a surface tension altering agent, wherein the surface tension altering agent is selected from the group consisting of surfactants, fluoro surfactants, silicone surfactants, siloxane, and similar materials. [0160] E-5. The electrode ink of E-1 to E-4, [0161] further comprising quaternized poly-vinyl alcohol. [0162] E-6. The electrode ink of E-1 to E-5, [0163] wherein the pore forming agent is selected from the group consisting of an ammonium bicarbonate, ammonium carbonate, sodium carbonate, sodium bicarbonate, similar materials, and mixtures thereof. [0164] E-7. The electrode ink of E-1 to E-6, [0165] wherein the pore forming agent is a leavening agents, wherein the leavening agent is selected from the group consisting of air, steam, yeast, baking soda, baking powder, similar materials, and mixtures thereof. [0166] F-1. A method of producing an electrode, comprising: [0167] growing the electrode on a reinforcement layer via hydrothermal deposition, electrodeposition, room condition deposition, or a similar process. [0168] F-2. The method of F-1, [0169] wherein the electrode comprises platinum, molybdenum, nickel, cobalt, boron, cerium, iron, tin, sulfur, phosphorus, fluorine, oxygen, hydroxide, similar materials, or mixtures thereof. [0170] F-3. The method of F-1 to F-2, [0171] wherein the electrode is supported on a conductive support, wherein the conductive support comprises such as carbon (Vulcan, Ketjen black, etc.), nickel, iron, titanium, stainless steel, or combinations of these materials. [0172] F-4. The method of F-1 to F-3, [0173] wherein the electrode comprises a nickel iron oxide (NiFe.sub.2O.sub.4), [0174] wherein the reinforcement layer comprises a nickel foam or nickel felt. [0175] F-5. The method of any of F-1 to F-4, [0176] wherein the electrode comprises Pt and carbon, [0177] wherein the reinforcement layer comprises a nickel foam, nickel felt, or a carbon fiber reinforcement layer.
[0178] The foregoing description has been presented for purposes of illustration and description only. It is not intended to be exhaustive or to limit the application to the precise form disclosed, and modifications and variations are possible and/or would be apparent in light of the above teachings or may be acquired from practice of the application. The embodiments were chosen and described in order to explain the principles of the application and its practical application to enable one skilled in the art to utilize the application in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of any issued patent be defined by the claims appended hereto.
