Improved electrochemical membrane

Abstract

The present disclosure relates to an electrolyzer composite membrane, and in particular to a composite membrane having at least two reinforcement layers including a microporous polymer structure and having surprisingly high puncture resistance. The electrolyzer composite membrane has a recombination catalyst configured to be located closer to the anode than the cathode in a membrane electrode assembly (MEA). The disclosure also relates to a membrane electrode assembly and an electrolyzer including the membrane, as well as a method for producing the membrane.

Description

[Technical field]

[0001] Field The present disclosure relates to polymer electrolyte membranes, and in particular to composite membranes having at least two reinforcing layers comprising a microporous polymer structure and having high puncture resistance. [Background technology]

[0002] background Water electrolysis is a highly attractive clean energy source for reducing carbon emissions. During electrolysis, electricity is used to split water into hydrogen and oxygen, producing hydrogen gas. The oxygen produced can be released into the atmosphere or captured or stored, for example for supply as an industrial or medical gas. Polymer electrolyte membrane (PEM) water electrolysis is a very promising technology that produces high gas purity, dynamic power range and current density, and is more efficient than its alkaline water electrolysis counterpart. The hydrogen produced during electrolysis can be compressed and later used to power any hydrogen fuel cell electrical application.

[0003] In an electrolysis device, the half-reaction that occurs at the anode is H2O→O2+2H + +2e - The half-reaction that occurs at the cathode is 2H + +2e - →H2. H + Cations migrate through the PEM from the anode to the cathode, producing H2 on the cathode side (see Figure 11). However, it is very important to minimize the crossover of molecular hydrogen and oxygen through the PEM, as they can adversely affect the faradaic efficiency of the electrolyzer and contribute to degradation of the PEM, and importantly, high concentrations of hydrogen on the anode side become a safety concern if the hydrogen concentration in the hydrogen and oxygen mixture reaches the explosive limit of 4%. Excessive crossover of hydrogen through the PEM can be exacerbated by cracking or puncturing the PEM.

[0004] In electrolyzer applications, the PEM is part of a membrane electrode assembly (MEA). The MEA is the central component of the electrolyzer where the electrochemical reaction to produce H2 occurs. A typical MEA includes a PEM that is coated on either of its exterior surfaces with a catalyst to form a catalyst coated membrane (CCM), or a PEM with a catalyst layer (i.e., an anode and a cathode) on either side. In some embodiments, the MEA is a five-layer MEA that includes a PEM with a cathode and an anode, and two liquid / gas diffusion layers (also known as fluid transport layers or FTLs) attached to the two exterior surfaces of the coated catalyst or catalyst layers. Typically, the cathode is about 1.0-2.0 mg metal / cm 2 The anode is a layer of platinum black or platinum on carbon (Pt / C) present at a loading ranging from about 1.0 to 4.0 mg metal / cm 2 The catalyst loading ranges from about 100 nm to about 150 nm, and the catalyst loading ranges from about 100 nm to about 150 nm.

[0005] High ionic conductivity, high durability, minimal hydrogen crossover, and low cost are all desirable qualities in an electrolyzer PEM. However, as a practical engineering problem, optimizing these properties often creates conflicts and trade-offs must be accepted. Conductance can be increased by reducing the thickness of the membrane. Thinner PEMs also reduce cost because ionomers are expensive and less is used. However, as the membrane gets thinner, hydrogen permeation increases, which impairs conductivity, resulting in thinner membranes having equal or lesser conductance than thicker membranes. In addition, thinner membranes are weaker and often lack sufficient mechanical durability for harsh operating conditions such as high temperature or pressure. Reducing the physical thickness of the membrane can make it more susceptible to damage or puncture from other electrochemical device components (e.g., fluid transport layers including titanium felt / platinized titanium fiber felt or mesh) and can shorten the cell's lifespan. Most importantly, hydrogen crossover in electrolyzer applications is dangerous, as hydrogen produced at the cathode end of the PEM travels to the anode and encounters the oxygen stream produced at the anode, where a dangerous and potentially explosive reaction can occur between H2 and O2 if the level of H2 in O2 reaches 5-95%. Traditionally, electrolyzer applications use PEMs with thicknesses greater than 100μm, and closer to 200μm, to minimize electrical resistance and improve performance, while at the same time keeping hydrogen crossover to a maximum of 2% H2 in O2 (usually the safety limit is considered to be 50% of the lower explosive limit, which is 4% H2 in O2).

[0006] In addition to increasing the thickness of the PEM to an acceptable level to minimize hydrogen crossover, the current state of the art has also explored other approaches, such as the inclusion of a recombination catalyst layer (e.g., a platinized current collector). The recombination catalyst layer controls and catalyzes the excess permeate hydrogen crossover from the cathode with oxygen from the anode to produce water and finally electrochemically oxidizes the permeate hydrogen to protons. These protons can then permeate the PEM again and be reduced at the cathode. Another approach is to use an external catalytic gas recombiner to reduce gas impurities.

[0007] Perforation of the PEM can be particularly problematic in electrolyzer applications that use fluid transport layers disposed on either side of the MEA. The fluid transport layers of electrolyzers typically comprise porous layers (typical pore size 1-200 microns) or metal meshes. Porous layers can include felt, paper, woven materials, among others. The fluid transport layers of cathodic electrolyzers typically comprise carbon fibers, and the anode fluid transport layers typically comprise titanium felt, platinized titanium fiber felt, or metal mesh (e.g., titanium metal mesh). Carbon or metal fibers and meshes can cause the PEM to perforate when the fluid transport layers are compressed against the MEA (the PEM sandwiched between the electrodes) during electrolyzer fabrication. Access to membranes with higher proton conductivity is therefore limited by transmembrane resistance requirements.

[0008] Finally, electrolyzers using PEMs can fail due to pinholes that develop and propagate through the polymer electrolyte membrane (especially at high pressure differentials across the membrane due to the high pressures experienced on the cathode side of the membrane as a result of hydrogen generation), and thus can fail and reach potentially dangerous levels of molecular hydrogen in oxygen as a result of hydrogen crossover through these pinholes. Furthermore, passing electronic current through the PEM can cause these devices to fail and short out the system.

[0009] State-of-the-art approaches to improve the mechanical resistance and puncture resistance properties of PEMs include reinforcing the polymer electrolyte membrane with a layer of microporous polymer structure that is fully imbibed with the polymer electrolyte (e.g., ionomer) and therefore fully conductive to ions. However, even reinforced PEMs can be subject to perforations during assembly of the membrane electrode assembly (MEA), the PEM with the electrodes and the liquid / gas diffusion layers (also known as fluid transport layers or FTLs), during electrolyzer manufacturing, and during electrolyzer operation.

[0010] Therefore, a need exists for a thin composite membrane that exhibits greater resistance to puncture and subsequent shorting by electrolyzer components than state-of-the-art composite membranes while maintaining high performance and low ionic resistance, is stable at the high pressure and high temperature operating conditions of the electrolyzer, and minimizes hydrogen crossover (maintaining hydrogen crossover below the safety limit of 2% hydrogen in oxygen). Summary of the Invention

[0011] Abstract The inventors have made efforts to solve the above-mentioned problems. The inventors have surprisingly discovered that for a given total content of microporous polymer structures and thickness of the PEM at 50% RH, distributing the total content of the microporous polymer structures between two or more reinforcing layers increases the resistance of the PEM to puncture by electrolyzer components (e.g., fluid diffusion layers and / or electrodes) during electrolyzer manufacture, compared to a PEM with the same content of reinforcing material in a single reinforcing layer. This maximizes the mechanical resistance of the membrane for a given content of reinforcing structures while minimizing hydrogen crossover through the electrolyzer composite membrane, thus allowing the membrane thickness to be reduced compared to state-of-the-art electrolyzer composite membranes. Furthermore, the addition of a recombination catalyst to the electrolyzer composite membrane, which is placed closer to the anode than the cathode in the MEA, or near or adjacent to the anode, further catalyzes the reduction of hydrogen that may have permeated from the cathode towards the anode, before the hydrogen reaches the anode in a controlled manner. Thus, the electrolyzer composite membranes disclosed herein exhibit minimal hydrogen crossover, even in embodiments where the electrolyzer composite membrane is much thinner than state of the art electrolyzer composite membranes.

[0012] In a first aspect, a) at least two reinforcement layers, where each of the at least two reinforcement layers comprises a microporous polymer structure; and b) an ion exchange material (IEM) at least partially absorbed within the microporous polymeric structure of each of said at least two reinforcement layers, causing said microporous polymeric structure to be occlusive; and c) recombination catalyst; An electrolyzer composite membrane is provided, comprising:

[0013] The recombination catalyst may be configured to be disposed closer to the anode than to the cathode of the electrolyzer composite membrane electrode assembly (MEA). The recombination catalyst may be configured to be disposed adjacent to the anode of the electrolyzer composite membrane electrode assembly (MEA). Adjacent to the anode, in the context of this disclosure, can mean that the recombination catalyst is closer to the anode than to the cathode in the MEA. The portion of the electrolyte composite membrane disposed adjacent to the anode may be disposed in contact with the anode. The recombination catalyst may be disposed in contact with the anode. In the context of this disclosure, "in contact with" includes "in direct contact with" and "indirect contact with". Thus, in some embodiments, the recombination catalyst may be disposed in direct contact with the anode (without any intervening layer or element). In other embodiments, the recombination catalyst may be disposed in indirect contact with the anode. In these embodiments, there may be at least one intervening layer between the recombination catalyst and the anode. The electrolyzer composite membrane may include a recombination catalyst disposed closer to the anode than the cathode in the MEA, but configured not to be in direct contact with the anode. For example, the electrolyzer composite membrane may include one or more ionomer layers disposed between the recombination catalyst and the anode. The electrolyzer composite membrane may be configured to include one or more additives disposed between the recombination catalyst and the anode in the MEA. The electrolyzer composite membrane may have a recombination catalyst (e.g., a recombination catalyst layer) disposed on an outermost surface of the membrane, and configured to contact the anode during use without other intervening layers. The recombination catalyst may extend from the anode outermost surface of the membrane (i.e., a surface of the membrane configured to be disposed adjacent to or in contact with the anode) into the electrolyzer composite membrane. For example, the recombination catalyst may extend from the outermost surface of the membrane to about half the thickness of the membrane.

[0014] The thickness of the electrolyzer composite membrane can be measured from the surface configured to be placed in contact with the cathode in use to the surface configured to be placed in contact with the anode in use. The recombination catalyst can be present at about 1% to about 50% of the thickness of the electrolyzer composite membrane. The location of the recombination catalyst within the electrolyzer composite membrane can be defined with reference to the thickness of the membrane and the outermost surface of the membrane that contacts the cathode and anode, respectively. In some embodiments, the recombination catalyst can be present at the outermost surface of the electrolyzer composite membrane configured to be placed in contact with the anode, and can extend into the membrane and be present within a range of about 1 / 2 to about 1 / 25, or about 1 / 25 to about 1 / 10, or about 1 / 10 to about 5 / 100, or about 5 / 100 to about 1 / 100 of the thickness of the membrane. In some embodiments, the recombination catalyst can be present in a separate layer. For example, the recombination catalyst can be mixed with an ionomer and placed as a layer on the outermost surface of the electrolyzer composite membrane configured to contact the anode in use. The recombination catalyst may be present in a catalyst support. The recombination catalyst may be dispersed within a portion of the thickness of the membrane. The recombination catalyst may be absorbed within at least one reinforcement layer of the electrolyzer composite membrane.

[0015] The electrolyzer composite membrane may have a thickness of at least 30 μm at 50% RH. The microporous polymer structure may be present in a total amount of at least about 10% by volume, based on the total volume of the composite membrane.

[0016] The recombination catalyst can be a catalyst capable of catalyzing the reaction between molecular hydrogen and molecular oxygen to produce water. In other words, the recombination catalyst can be a molecular hydrogen decomposition catalyst. The recombination catalyst can include a single recombination catalyst species or a mixture of recombination catalyst species. The recombination catalyst can include one or more catalytic species selected from Pt, Ir, Ni, Co, Pd, Ti, Sn, Ta, Nb, Sb, Pb, Mn, and Ru, their oxides, and mixtures thereof. The recombination catalyst can include platinum group metals (group 10 metals), such as platinum, palladium, iridium, rhodium, ruthenium, or osmium, alloys of platinum group metals, mixed oxides of platinum group metals with other metals, such as cerium and titanium, and mixtures thereof, or the recombination catalyst includes one or more of Pt, Ir, Ni, Co, Pd, Ti, Sn, Ta, Nb, Sb, Pb, Mn, and Ru, their oxides, and mixtures thereof. The recombination catalyst may comprise a single recombination catalyst species or a mixture of recombination catalyst species. The recombination catalyst may be mixed with an ion exchange material and / or the recombination catalyst may be present on a recombination catalyst support material.

[0017] The recombination catalyst may be present in a recombination catalyst layer configured to be closer to the anode than the cathode in the MEA or electrolyzer. The recombination catalyst may be dispersed across at least a portion of the composite electrolyte membrane. In the context of this disclosure, in all cases, at least a portion of the recombination catalyst may be configured to be located closer to the anode than the cathode in the MEA or electrolyzer. The recombination catalyst or recombination catalyst layer may include one or more recombination catalyst species and may optionally further include at least one of a support such as an ion exchange material or carbon particles. The recombination catalyst metal species may be mixed with a support (e.g., carbon black) and coated onto the composite membrane. In other embodiments, the recombination catalyst metal species may be mixed with a support (e.g., carbon black or ionomer) and laminated onto the composite membrane.

[0018] The support material can include silica, zeolites, carbon, and oxides and carbides of Group IVB, VB, VIB, VIIB and VIII transition metals, and combinations thereof. Carbon is a particularly preferred support material. They should preferably have a high surface area, so that their size is small, less than 75 nm, or preferably less than 50 nm, or less than 25 nm. They can also be porous, if necessary. The use of high surface area supports is particularly advantageous, since they allow the recombination catalyst to be highly dispersed, resulting in a higher catalytic activity per unit weight compared to unsupported low surface area catalysts of the same composition.

[0019] The recombination catalyst may be present in an electrolyzer composite membrane electrode assembly (MEA) and / or a recombination catalyst layer configured to be positioned closer to the anode than the cathode in the electrolyzer. The electrolyte composite membrane may define a cathode outermost surface configured to be positioned closer to the cathode than the anode in the electrolyte composite membrane electrode assembly or electrolyzer, and an anode outermost surface configured to be positioned closer to the anode side than the cathode in the electrolyzer or electrolyzer composite membrane electrode assembly. Each of the at least two reinforcing layers may define a first surface and a second surface opposite the first surface, the first surface of the reinforcing layer configured to be positioned at or near the cathode being the cathode outermost surface, and the second surface of the reinforcing layer configured to be positioned at or near the anode being the anode outermost surface.

[0020] The recombination catalyst was added to the composite electrolyte membrane at a concentration of 0.1 mg / cm. 2 The recombination catalyst can be present in the composite electrolyte membrane at a loading of less than about 0.0001 mg / cm. 2 ~about 0.1mg / cm 2 , or about 0.0005 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.0008 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.001 mg / cm 2 ~about 0.1mg / cm 2, or about 0.0015 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.002 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.0025 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.003 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.0043 mg / cm 2 ~About 0.0.005mg / cm 2 , or about 0.0035 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.005 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.007 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.009 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.01 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.04 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.085 mg / cm 2 ~about 0.1mg / cm 2 , or about 0.013 mg / cm 2 ~about 0.015mg / cm 2 , or about 0.0001 mg / cm 2 ~about 0.001mg / cm 2 , or about 0.0001 mg / cm 2 ~about 0.005mg / cm 2 , or about 0.0001 mg / cm 2 ~about 0.008mg / cm 2 , or about 0.0001 mg / cm 2 ~about 0.01mg / cm 2 , or about 0.0001 mg / cm 2 ~about 0.05mg / cm 2 , or about 0.001 mg / cm 2 ~about 0.01mg / cm 2 , or about 0.004 mg / cm 2~about 0.01mg / cm 2 The compound can be present in a loading range of 100 to 200 mg / kg.

[0021] In water electrolysis devices, undesirable side reactions can occur between hydrogen and oxygen to produce hydrogen peroxide (H2O2), which can decompose into peroxide radicals that can attack the membrane and electrolyzer components. To mitigate this problem, the electrolyzer composite membrane can further include an additive to decompose hydrogen peroxide and / or to scavenge peroxide radicals. The additive can be a peroxide decomposition catalyst, a radical scavenger, a free radical decomposition catalyst, a self-regenerating antioxidant, a hydrogen donor primary antioxidant, a free radical scavenger secondary antioxidant, an oxygen absorber, and the like. The additive can include Ce, Mn, or oxides thereof. For example, the additive can be cerium dioxide (ceria). For the avoidance of doubt, the additive can be added in addition to the recombination catalyst.

[0022] The electrolyzer composite membrane can include two reinforcing layers. The composite membrane can include three reinforcing layers. The electrolyzer composite membrane can include four reinforcing layers. The electrolyzer composite membrane can include five reinforcing layers. The electrolyzer composite membrane can include between 2 and 10 reinforcing layers. The electrolyzer composite membrane can include any suitable number of reinforcing layers.

[0023] The electrolyzer composite membrane may define a first composite membrane surface and a second composite membrane surface opposite the first composite membrane surface. An ion exchange material may be present in at least one layer of the first composite membrane surface and / or the second composite membrane surface. The electrolyzer composite membrane may include a first layer of ion exchange material on the first composite membrane surface. The electrolyzer composite membrane may include a second layer of ion exchange material on the second composite membrane surface. The first layer of ion exchange material may include a recombination catalyst, and the first layer of ion exchange material may be configured to be positioned closer to the anode than the cathode of the electrolyzer membrane electrode assembly (MEA). The electrolyzer composite membrane may have at least one further layer of ion exchange material on the first layer of ion exchange material and / or the second layer of ion exchange material. The at least one further layer of ion exchange material present on the first composite membrane surface or on the second composite membrane surface, which may be configured to be positioned on or towards the anode side of the electrolyzer, includes a recombination catalyst.

[0024] The composite membrane may have a thickness of at least about 20 μm at 50% relative humidity (RH). The composite membrane may have a thickness of about 20 μm to about 250 μm at 50% relative humidity (RH). The composite membrane may have a thickness of about 20 μm to about 120 μm, or about 20 μm to about 90 μm, or about 20 μm to about 80 μm, or about 20 μm to about 75 μm, or about 20 μm to about 70 μm, or about 30 μm to about 60 μm, or about 20 μm to about 50 μm, or about 20 μm to about 40 μm, or about 20 μm to about 30 μm, Or it may have a thickness of about 25 μm to about 35 μm, or about 40 μm to about 50 μm, or about 60 μm to about 120 μm, or about 60 μm to about 80 μm, or about 80 μm to about 120 μm, or about 100 μm to about 120 μm, or about 30 μm to about 40 μm, or about 30 μm to about 60 μm, or about 40 μm to about 60 μm. The composite membrane can have a thickness at 50% RH of about 20 μm, or about 25 μm, or about 30 μm, or about 35 μm, or about 40 μm, or about 45 μm, or about 50 μm, or about 55 μm, or about 60 μm, or about 65 μm, or about 70 μm, or about 75 μm, or about 80 μm, or about 85 μm, or about 90 μm, or about 95 μm, or about 100 μm, or about 105 μm, or about 110 μm, or about 115 μm, or about 120 μm, or about 150 μm, or about 180 μm, or about 200 μm, or about 220 μm, or about 230 μm, or about 250 μm.

[0025] In the context of the present disclosure, the total content of microporous polymer structures in a composite membrane is the total mass of microporous polymer structures in the composite membrane per total area of ​​the composite membrane (g / m 2). A composite membrane can include more than one type of microporous polymer structure. For example, a composite membrane can include a single type of microporous polymer structure (e.g., ePTFE membrane) present in at least two reinforcement layers. A composite membrane can include at least two reinforcement layers, each of which can include a different type of microporous polymer structure (e.g., a fluorinated polymer and a hydrocarbon polymer). A composite membrane can include at least two reinforcement layers, a first layer of the at least two reinforcement layers can include a single type of microporous polymer structure (e.g., ePTFE membrane) and a second layer of the at least two reinforcement layers can include a single type of microporous polymer structure (e.g., a hydrocarbon polymer) that is different from the microporous polymer structure of the first layer of the at least two reinforcement layers.

[0026] The total volume of the microporous polymer structures in the electrolyzer composite membrane can be at least about 10% by volume, based on the total volume of the composite membrane. The total volume of the microporous polymer structures in the electrolyzer composite membrane can be at least about 10% by volume, or at least about 15% by volume, or at least about 20% by volume, or at least about 25% by volume, or at least about 30% by volume, or at least about 35% by volume, or at least about 40% by volume, or at least about 45% by volume, or at least about 50% by volume, or at least about 55% by volume, or at least about 60% by volume, or at least about 65% by volume, or at least about 70% by volume, based on the total volume of the composite membrane.

[0027] The total volume of the microporous polymer structure in the electrolysis device composite membrane is about 10% by volume to about 80% by volume, or about 15% by volume to about 80% by volume, or about 20% by volume to about 80% by volume, or about 25% by volume to about 80% by volume, or about 30% by volume to about 80% by volume, about 40% by volume to about 80% by volume, about 50% by volume to about 80% by volume, or about 60% by volume to about 80% by volume, or about 65% by volume to about 80% by volume, or about It can be 10% by volume to about 60% by volume, or about 10% by volume to about 50% by volume, or about 10% by volume to about 40% by volume, or about 10% by volume to about 30% by volume, or about 10% by volume to about 20% by volume, or about 15% by volume to about 30% by volume, or about 20% by volume to about 40% by volume, or about 40% by volume to about 60% by volume, or about 40% by volume to about 50% by volume, or about 20% by volume to about 40% by volume, or about 20% by volume to about 50% by volume. The total volume of the microporous polymer structure in the electrolyzer composite membrane can be about 10% by volume, or about 15% by volume, or about 20% by volume, or about 25% by volume, or about 30% by volume, or about 35% by volume, or about 40% by volume, or about 45% by volume, or about 50% by volume, or about 55% by volume, or about 60% by volume, or about 65% by volume, or about 70% by volume, or about 80% by volume, based on the total volume of the composite membrane.

[0028] The composition of the at least two reinforcing layers can be the same, or the composition of the at least two reinforcing layers can be different.

[0029] The microporous polymer structure may comprise a fluorinated polymer. The microporous polymer structure may comprise one or more fluorinated polymers selected from the group comprising polytetrafluoroethylene (PTFE), poly(ethylene-co-tetrafluoroethylene) (EPTFE), expanded polytetrafluoroethylene (ePTFE), polyvinylidene fluoride (PVDF), expanded polyvinylidene fluoride (PVDF), expanded poly(ethylene-co-tetrafluoroethylene) (eEPTFE) or mixtures thereof. Preferably, the fluorinated polymer may be perfluorinated expanded polytetrafluoroethylene (ePTFE).

[0030] The microporous polymer structure may comprise a hydrocarbon polymer, which may include polyethylene, polypropylene, polycarbonate, track-etched polycarbonate, polystyrene, polysulfone, PES, PEN, or mixtures thereof.

[0031] In the context of the present disclosure, the total mass per area of ​​the microporous polymer structure in the electrolyzer composite membrane is considered to be the sum of the content of the microporous polymer structure in each reinforcing layer of the electrolyzer composite membrane. In embodiments in which the microporous polymer structure comprises ePTFE, the total mass per area of ​​the microporous polymer structure in the electrolyzer composite membrane is at least about 8 g / m, based on the total area of ​​the composite membrane. 2 The total mass per area of ​​the microporous polymer structure can be at least about 10 g / m, based on the total area of ​​the composite membrane. 2 , or at least about 15 g / m 2 , or at least about 20 g / m 2 , or at least about 25 g / m 2 , or at least about 30 g / m 2 , or at least about 35 g / m 2 , or at least about 40 g / m 2 , or at least about 45 g / m 2 , or at least about 50 g / m 2 , or at least about 55 g / m 2 , or at least about 60 g / m 2 , or at least about 65 g / m 2 , or at least about 70 g / m 2 , or at least about 75 g / m 2 It can be.

[0032] In embodiments in which the microporous polymer structure comprises ePTFE, the total mass (mass per area) of the microporous polymer structure within the electrolyzer composite membrane is about 8 g / m, based on the total area of ​​the composite membrane. 2 ~about 80g / m 2 , or about 8 g / m 2 ~about 70g / m 2 , or about 8 g / m 2~about 60g / m 2 , or about 8 g / m 2 ~about 60g / m 2 , or about 8 g / m 2 ~about 50g / m 2 , or about or about 8 g / m 2 ~about 40g / m 2 , or about 8 g / m 2 ~Approx. 35g / m 2 , or about 8 g / m 2 ~About 30g / m 2 , or about 8 g / m 2 ~about 20g / m 2 , or about 8 g / m 2 ~about 15g / m 2 The total mass per area of ​​the microporous polymer structure can be about 15 g / m, based on the total area of ​​the composite membrane. 2 ~About 30g / m 2 The total mass per area of ​​the microporous polymer structure can be about 10 g / m, based on the total area of ​​the composite membrane. 2 ~about 15g / m 2 The total content (mass per area) of the microporous polymer structure in the electrolyzer composite membrane can be about 10 g / m, based on the total area of ​​the composite membrane. 2 ~Approx. 18g / m 2 The total mass per area of ​​the microporous polymer structure can be about 8 g / m, based on the total area of ​​the composite membrane. 2 ~about 15g / m 2 The total mass per area of ​​the microporous polymer structure can be about 20 g / m, based on the total area of ​​the composite membrane. 2 ~about 80g / m 2 , or about 30 g / m 2 ~about 70g / m 2 , or about 20 g / m 2 ~about 50g / m 2 , or about 30 g / m 2 ~about 60g / m 2 , or about 15 g / m 2 ~about 40g / m 2 , or about 15 g / m 2 ~About 30g / m 2 , or about 15 g / m 2 ~about 25g / m2 , or about 20 g / m 2 ~about 40g / m 2 g, or about 25 g / m 2 ~Approx. 35g / m 2 It can be.

[0033] In an embodiment in which the microporous polymer structure comprises ePTFE, each of the at least two reinforcing layers of the reinforcing structure has a mass of about 5 g / m2 based on the total area of ​​the composite membrane. 2 , or about 5.5 g / m 2 , or about 6 g / m 2 , or about 7 g / m 2 , or about 8 g / m 2 , or about 9 g / m 2 , or about 10 g / m 2 , or about 11 g / m 2 , or about 12 g / m 2 , or about 13 g / m 2 , or about 14 g / m 2 , or about 15 g / m 2 , or about 16 g / m 2 , or about 17 g / m 2 , or about 18 g / m 2 , or about 19 g / m 2 , or about 20 g / m 2 , or about 30 g / m 2 g, or about 40 g / m 2 , or about 50 g / m 2 , or about 60 g / m 2 , or about 70 g / m 2 , or about 80 g / m 2 The microporous polymer structure may have a mass of 0.1 to 0.5 microporous polymer.

[0034] Each of the at least two reinforcing layers of the reinforcing structure has a strength of at least 5 g m -2 Each of the at least two reinforcing layers of the reinforcing structure may have a microporous polymer structure mass of about 5 g m based on the total area of ​​the composite membrane. -2 ~Approx. 75g m -2 , or about 10 g / m 2 ~about 60g / m 2 , or about 15 g / m 2 ~About 30g / m2 , or about 15 g / m 2 ~about 25g / m 2 , or about 20 g / m 2 ~about 40g / m 2 , or about 25 g / m 2 ~Approx. 35g / m 2 , or about 5 g / m 2 ~about 25g / m 2 , or about 5 g / m 2 ~about 10g / m 2 , or about 10 g / m 2 ~about 25g / m 2 , or about 10 g / m 2 ~about 15g / m 2 , or about 15 g / m 2 ~About 30g / m 2 , or about 8 g / m 2 ~about 10g / m 2 , or about 30 g / m 2 ~about 50g / m 2 The microporous polymer structure may have a content of

[0035] In embodiments in which the microporous polymer structure comprises a hydrocarbon polymer, the total mass per area of ​​the microporous polymer structure is at least about 2.5 g / m, based on the total area of ​​the composite membrane. 2 , or at least about 3 g / m 2 , or at least about 4 g / m 2 , or at least about 7 g / m 2 , or at least about 8 g / m 2 , or at least about 9 g / m 2 , or at least about 10 g / m 2 , or at least about 12 g / m 2 , or at least about 15 g / m 2 , or at least about 17 g / m 2 , or at least about 20 g / m 2 , or at least about 23 g / m 2 , or at least about 25 g / m 2 , or at least about 27 g / m 2 , or at least about 30 g / m 2 , or at least about 35 g / m 2, or at least about 40 g / m 2 The total mass per area of ​​the microporous polymer structure can be about 2.5 g / m, based on the total area of ​​the composite membrane. 2 ~about 40g / m 2 , or about 2.5 g / m 2 ~Approx. 35g / m 2 , or about 2.5 g / m 2 ~About 30g / m 2 , or about 2.5 g / m 2 ~about 25g / m 2 , or about 2.5 g / m 2 ~about 20g / m 2 , or about 2.5 g / m 2 ~about 15g / m 2 , or about 2.5 g / m 2 ~about 10g / m 2 , or about 2.5 g / m 2 ~about 5g / m 2 , or about 5 g / m 2 ~about 40g / m 2 , or about 10 g / m 2 ~about 40g / m 2 , or about 15 g / m 2 ~about 40g / m 2 , or about 20 g / m 2 ~about 40g / m 2 , or about 25 g / m 2 ~about 40g / m 2 , or about 30 g / m 2 ~ ~About 40g / m 2 , or about 35 g / m 2 ~about 40g / m 2 , or about 10 g / m 2 ~About 30g / m 2 , or about 20 g / m 2 ~about 40g / m 2 , or about 30 g / m 2 ~about 40g / m 2 It can be.

[0036] The composite membrane may have an average puncture force of at least about 60 gF (0.59 N) when measured according to the Average Puncture Force Burst Test described below. For example, the composite membrane may have an average puncture force of at least about 60 gF (0.59 N), or at least about 65 gF (0.64 N), or at least about 70 gF (0.69 N), or at least about 75 gF (0.74 N), or at least about 80 gF (0.78 N), or at least about 90 gF (0.88 N), or at least about 100 gF (0.98 N), or at least about 110 gF (1.08 N), at least about 120 gF (1.18 N), or at least about 130 gF (1.27 N), or at least about 140 gF (1.37 N), or at least about 150 gF (1.47 N), as measured by the Average Puncture Force Puncture Test described below.

[0037] The composite membrane has a puncture strength of about 60 gF (0.59 N) to about 150 gF (1.47 N) when measured according to the Average Puncture Force Breakdown Test described below, or about 60 gF (0.59 N) to about 140 gF (1.37 N), or about 60 gF (0.59 N) to about 130 gF (1.27 N), or about 60 gF (0.59 N) to about 120 gF (1.18 N), or about 60 gF (0.59 N) to about 110 gF (1.08 N), or about 60 gF (0.59 N) to about 10 It may have an average breaking force of 0gF (0.98N), or from about 60gF (0.59N) to about 90gF (0.88N), or from about 60gF (0.59N) to about 80gF (0.78N), or from about 60gF (0.59N) to about 75gF (0.74N), or from about 60gF (0.59N) to about 70gF (0.69N), or from about 70gF (0.69N) to about 90gF (0.88N), or from about 80gF (0.78N) to about 90gF (0.88N), or from about 65gF (0.64N) to about 75gF (0.74N).

[0038] The composite membrane may have an average puncture force of about 60 gF (0.59 N), or about 65 gF (0.64 N), or about 70 gF (0.69 N), or about 75 gF (0.74 N), about 80 gF (0.78 N), or about 85 gF (0.83 N), or about 90 gF (0.88 N), or about 100 gF (0.98 N), or about 110 gF (1.08 N), or about 120 gF (1.18 N), or about 130 gF (1.27 N), about 140 gF (1.37 N), or about 150 gF (1.47 N), as measured by the Average Puncture Force Puncture Test described below.

[0039] The at least two reinforcing layers may be in direct contact. Alternatively, the at least two reinforcing layers may not be in contact with each other. The at least two reinforcing layers may be separated by a distance d. In embodiments in which the at least two reinforcing layers are in direct contact, the distance d may be about 0 μm. The distance d may be about 0.1 μm to about 20 μm. The distance d may be about 0.1 μm to about 15 μm. The distance d may be about 0.1 μm to about 10 μm. The distance d may be about 10 μm to about 20 μm. The distance d may be about 10 μm to about 15 μm. The distance d may be about 15 μm to about 20 μm. The distance d may be about 2 μm to about 8 μm. The distance d may be about 2 μm to about 8 μm. The distance d may be about 2 μm to about 8 μm. The distance d can be from about 2 μm to about 8 μm. The distance d can be from about 2 μm to about 8 μm. The distance d can be from about 0.5 μm to about 10 μm. The distance d can be from about 1 μm to about 10 μm. The distance d can be from about 2 μm to about 8 μm. The distance d can be from about 4 μm to about 6 μm. The distance d can be from about 1 μm to about 5 μm. The distance d can be from about 5 μm to about 10 μm. The distance d can be from about 6 μm to about 8 μm. The distance d can be about 0.1 μm, or about 0.5 μm, or about 1 μm, or about 2 μm, or about 3 μm, or about 4 μm, or about 5 μm, or about 6 μm, or about 7 μm, or about 8 μm, or about 9 μm, or about 10 μm, or about 11 μm, or about 12 μm, or about 13 μm, or about 14 μm, or about 15 μm, or about 16 μm, or about 17 μm, or about 18 μm, or about 19 μm, or about 20 μm.

[0040] The at least two reinforcement layers may be separated by at least one internal layer of ion exchange material (IEM). Each of the at least one internal layer of ion exchange material may include a single ion exchange material. Each of the at least one internal layer of ion exchange material may include a mixture of two or more ion exchange materials. Each of the at least one internal layer of ion exchange material may include at least one ionomer. The at least one internal ionomer may include a proton conducting polymer. The proton conducting polymer may include a hydrocarbon ionomer. The proton conducting polymer may include a perfluorinated ionomer. The proton conducting polymer may include a perfluorosulfonic acid (PFSA). Each of the at least one internal layer of ion exchange material may be about 1 μm to about 20 μm thick, for example, about 2 μm or about 10 to about 12 μm thick.

[0041] The at least two reinforcement layers may be separated by one layer of ion exchange material (IEM). The layer of ion exchange material may comprise a single ion exchange material. The layer of ion exchange material may comprise a mixture of more than one ion exchange material.

[0042] The at least two reinforcement layers can be separated by two or more layers of ion exchange material. At least two of the two or more layers of ion exchange material can comprise different ion exchange materials. At least two of the two or more layers of ion exchange material can comprise the same ion exchange material.

[0043] The at least two reinforcement layers can be separated by a layer of ion exchange material (IEM), where the ion exchange material comprises more than one layer of ion exchange material, and the layer of ion exchange material disposed between the at least two reinforcement layers is formed from a different ion exchange material.

[0044] Each of the at least two reinforcement layers can have a first surface and a second surface, or at least one or both of the first surface and the second surface of each reinforcement layer can be at least partially impregnated with ion exchange material.

[0045] In embodiments where the composite membrane comprises two reinforcement layers, the first reinforcement layer may comprise a first surface and a second surface and the second reinforcement layer may comprise a first surface and a second surface. The first surface of the first of the at least two reinforcement layers may be at least partially impregnated with ion exchange material. The second surface of the second of the at least two reinforcement layers may be at least partially impregnated with ion exchange material. Both the first and second surfaces of the at least two reinforcement layers may be at least partially impregnated with ion exchange material.

[0046] In embodiments in which both the first surface of the first reinforcement layer and the second surface of the second reinforcement layer are at least partially impregnated with ion exchange material, the ion exchange material of the first surface of the first reinforcement layer can be the same as or different from the ion exchange material of the second surface of the second reinforcement layer.

[0047] The microporous polymer structure may be partially imbibed with the ion exchange material. The microporous polymer structure may be completely imbibed with the ion exchange material. In embodiments where the composite membrane has two reinforcing layers, the microporous polymer structure of the two reinforcing layers may be completely imbibed with the ion exchange material. Furthermore, the composite membrane may include two additional layers of ion exchange material on the first and second surfaces of the composite membrane. Furthermore, the first and second reinforcing layers may be separated from each other by an inner layer of ion exchange material. The layers of ion exchange material forming the first and second surfaces of the composite membrane and / or disposed between the two reinforcing layers may include the same or different ion exchange materials. For example, the ion exchange material may be an ionomer.

[0048] The total average equivalent volume of the ion exchange material can be from about 240 cc / molar equivalent to about 1200 cc / molar equivalent. The average equivalent volume of the ion exchange material can be from about 240 cc / molar equivalent to about 720 cc / molar equivalent. The average equivalent volume of the ion exchange material can be from about 350 cc / molar equivalent to about 475 cc / molar equivalent. The total average equivalent volume of the ion exchange material can include the total volume of the ion exchange material distributed between all ion exchange material layers of the composite membrane. The ion exchange material can have a density of about 1.9 g / cc or greater at 0% relative humidity.

[0049] The ion exchange material is about 370 g / mol equivalent to about 2000 g / mol equivalent of SO3 - The ion exchange material can have a total equivalent weight (EW) of about 470 g / mol equivalent to about 1275 g / mol equivalent of SO3 - The ion exchange material can have a total equivalent weight (EW) of about 700 g / mol equivalent to about 1000 g / mol equivalent of SO3 - The ion exchange material can have a total equivalent weight (EW) of about 710 g / mol equivalent of SO3 - The ion exchange material can have an equivalent weight of about 810 g / mol equivalent of SO3 - The ion exchange material can have an equivalent weight of about 910 g / mol equivalent of SO3 - The equivalent weight of the mixture may be 0.01 to 0.05.

[0050] In embodiments where the composite membrane includes two reinforcement layers disposed in direct contact, the second surface of the first reinforcement layer and the first surface of the second reinforcement layer can be in direct contact.

[0051] In embodiments where the electrolyzer composite membrane includes two reinforcement layers disposed separately from one another, the second surface of the first reinforcement layer and the first surface of the second reinforcement layer may be separated by a layer of ion exchange material (i.e., an inner layer of ion exchange material). At least one inner layer of ion exchange material may not include a recombination catalyst. In some embodiments where the electrolyzer composite membrane includes two reinforcement layers disposed separately from one another, the second surface of the first reinforcement layer and the first surface of the second reinforcement layer may not be separated by a recombination catalyst layer. In embodiments where the composite membrane includes three reinforcement layers disposed separately from one another, the first reinforcement layer and the second reinforcement layer may be separated by a first inner layer of ion exchange material, and the second reinforcement layer and the third reinforcement layer may be separated by a second inner layer of ion exchange material.

[0052] The electrolyzer composite membrane may include a first surface and a second surface. The first surface of the composite membrane may include a first ion exchange material. The second surface of the composite membrane may include a second ion exchange material. The electrolyzer composite membrane may include at least one inner layer of ion exchange material between at least two reinforcement layers.

[0053] In embodiments where the composite membrane includes three or more reinforcement layers, all of the reinforcement layers can be in direct contact with each other. Alternatively, some of the reinforcement layers can be in direct contact with each other while some of the reinforcement layers can be separated from each other (e.g., by an inner layer of ion exchange material). Alternatively, all of the reinforcement layers can be separated from each other. In embodiments where the reinforcement layers are separated from each other, the reinforcement layers can be separated from each other by ion exchange material. For example, the composite membrane can include three or more reinforcement layers, each reinforcement layer being separated from the next reinforcement layer by one or more layers of ion exchange material. Additionally, the outer reinforcement layers can be at least partially impregnated with ion exchange material on their outer surface.

[0054] The electrolyzer composite membrane can further include a backer layer disposed on the first surface of the composite membrane, the second surface of the composite membrane, or both.

[0055] The electrolyzer composite membrane had a hydrogen crossover current of 0.5 A / cm at 55° C. using the hydrogen crossover detection method described herein. 2 The electrolyzer composite membrane may experience about 4% or less, preferably about 2% or less, and more preferably about 1% or less hydrogen crossover when measured at 2 bar pressure differential at 1000 rpm. The electrolyzer composite membrane may experience about 0% to about 2%, or about 0% to about 1%, or about 0.2% to about 1%, or about 0.3% to about 1%, or about 0.3% to about 0.9%, or about 0.5% to about 1%, or about 0.5% to about 1.5%, or about 1% to about 2%, or about 1.5% to about 2%, or about 0.6% to about 1.2% hydrogen crossover when measured by the hydrogen crossover detection method described herein.

[0056] In a second aspect, an electrolyzer composite membrane electrode assembly for an electrochemical device is provided, the membrane electrode assembly comprising: At least one electrode; and a composite membrane as described above in contact with said at least one electrode; Includes.

[0057] The electrolyzer composite membrane may be attached to at least one electrode. The electrolyzer composite membrane may be glued to at least one electrode. The electrolyzer composite membrane may be pressed against at least one electrode. The electrolyzer composite membrane may be fused to at least one electrode. At least one electrode may comprise doped carbon fibers.

[0058] The electrolyzer composite membrane electrode assembly may include a first electrode and a second electrode. The first electrode may form the anode. The second electrode forms the cathode. The anode may be in contact with the recombination catalyst of the electrolyzer composite membrane.

[0059] The electrolyzer composite membrane may include a first electrode layer and a second electrode layer. Each of the first electrode layer and the second electrode layer may be disposed on opposite surfaces of the electrolyzer composite membrane. The anode electrode layer may be disposed adjacent to or next to the surface of the electrolyzer composite membrane that includes the recombination catalyst.

[0060] The electrodes can include one catalyst or a mixture of catalysts. The electrodes can include metals or metal oxides. The electrodes can be dispersed in a support. The electrodes (e.g., cathode and / or anode) can be carbon / platinum electrodes with ionomer. The electrodes can include one or more of alloys including ionomer / Pt / Co / Pd, doped graphene / MoSx (cathode), RuO2 / IrO2 / Ir, Ru bimetal oxide, Ir / Pt bimetal oxide, Ti, Sn, Ta, Nb, Sb, Pb, Mn oxide mixed with Ir or Ru oxide, and the like. The electrodes can include a catalyst support selected from carbon (e.g., carbon black / CNT), or carbon nanoparticles doped with N, P, S, or B. The catalyst in one or more electrodes can be about 0.4-4.0 mg. metal / cm 2 The cathode can be present at a loading ranging from about 0.1 to 40 mg precious metal / cm. 2 , for example 0.0 to 2.0 mg metal / cm 2 , or about 1.0 to 2.0 mg metal / cm 2 , or about 0.2 to 1.0 mg metal / cm 2 The anode can be present in a loading range of about 0.4 to 4.0 mg. metal / cm 2 , or about 0.5 to 2.0 mg metal / cm 2 , or about 0.5 to 1.5 mg metal / cm 2 The catalyst may be present at a catalyst loading ranging from 0.1 to 100%.

[0061] One or more of the electrodes can include fibers. The electrodes can be fibrous electrodes. One or more of the electrodes can be doped fibers. One or more of the electrodes can include carbon fibers. The carbon fibers can have a diameter of about 5 μm to about 30 μm. One or more of the electrodes can include a porous layer (typical pore size 1-200 microns). The porous layer can include felt, paper, or woven materials, among others.

[0062] The electrolyzer composite membrane electrode assembly may comprise a fluid diffusion layer. The fluid diffusion layer may be selected from felt, paper or woven materials, carbon / carbon based diffusion layers, titanium porous sintered powder mesh / plate / fiber / felt, etc., stainless steel mesh or mixtures thereof. The fluid diffusion layer may comprise any suitable form such as fibers, mats, non-woven fabrics, etc. The fluid diffusion layers may sandwich the electrolyzer composite membrane and the electrodes. In other words, the fluid diffusion layers may be disposed behind one electrode / electrode layer or each electrode / electrode layer. In another aspect, there is provided an electrolyzer comprising the electrolyzer composite membrane or the electrolyzer composite membrane-electrode assembly as described above.

[0063] In another aspect, there is provided a method for making an electrolyzer composite membrane as described herein. a) providing a backer layer and coating the backer layer with a first ionomer by depositing a liquid layer of the first ionomer; b) depositing a first reinforcement layer comprising a microporous polymer structure onto the liquid layer of the first ionomer such that the first ionomer is imbibed or at least partially imbibed into the microporous polymer structure of the first reinforcement layer; c) optionally drying the laminate; d) coating the imbibed first reinforcing layer with a liquid layer of a second ionomer solution; e) depositing a second reinforcement layer comprising a microporous polymer structure onto the liquid layer of second ionomer such that the second ionomer is imbibed or at least partially imbibed into the microporous polymer structure of the second reinforcement layer; f) optionally drying the laminate; g) optionally coating the outermost surface of the laminate furthest from the backer with a third liquid layer of ionomer, such that the ionomer is at least partially imbibed into said microporous polymer structure; h) optionally drying the laminate; i) depositing a recombination catalyst layer and optionally drying the laminate; j) optionally depositing a fourth liquid layer of ionomer on said recombination catalyst layer; and k) drying the laminate; The process includes the steps of:

[0064] The method can include repeating steps d), e) and f) with additional reinforcing layers and liquid layers of ionomer and drying the laminate. For example, for an electrolyzer composite membrane including three reinforcing layers, a third liquid layer of ionomer solution can be deposited on the imbibed second reinforcing layer, a third reinforcing layer can be applied on top of the third liquid layer of ionomer solution, and the laminate can then be dried. In some embodiments, the process can include adding yet another ionomer and reinforcing layer and drying the laminate.

[0065] The electrolyzer composite membrane may be manufactured by sequentially coating and / or laminating the different components of the membrane. The manufacturing process may include a drying step after some or all of the coating or lamination steps. In some embodiments, the manufacturing process may include only a single drying step at the end of the process.

[0066] In step i), the recombination catalyst can be deposited as particles mixed with the ionomer to coat the outermost surface of the composite. A portion of the recombination catalyst particles can be absorbed within the outermost reinforcing layer. The recombination catalyst can be mixed with the ionomer and the support material as described above prior to coating.

[0067] In some embodiments, steps g) and h) can be omitted and the recombination catalyst can be deposited directly onto the reinforcing layer furthest from the backer. In embodiments where steps g) and h) are present, the composite membrane includes a layer of ionomer (i.e., unreinforced ionomer) disposed between the recombination catalyst and the reinforcing layer furthest from the backer.

[0068] In embodiments where two reinforcing layers are in contact with each other, the above method is modified to omit the step of coating the reinforcing layers with a separate solution of ionomer before applying the further reinforcing layer, e.g., in the above method, step d) is omitted.

[0069] The membrane electrode assembly may be prepared by depositing an anode on the surface of the electrolyzer composite membrane having the recombination catalyst and depositing a cathode on the opposite surface of the electrolyzer composite membrane (i.e., the surface without the recombination catalyst) after removing the backer. In the context of the present disclosure, depositing the electrodes (anode and / or cathode) may include any technique known in the art, such as coating, spraying, laminating, etc.

[0070] In some embodiments, the membrane electrode assembly may be prepared by depositing a cathode on a fluid diffusion layer to form a fluid diffusion electrode composite, and depositing the fluid diffusion electrode composite on a surface of the electrolyzer composite membrane furthest from the recombination catalyst. The anode may be deposited on the surface of the electrolyzer composite membrane closest to the recombination catalyst, and the fluid diffusion layer is deposited on the anode layer.

[0071] The electrodes (i.e., anode and cathode) may be deposited by any suitable technique known in the art. For example, a solid electrode layer may be pressed against the electrolyzer composite membrane by any suitable technique. Alternatively, a (liquid) electrode ink may be applied onto the electrolyzer composite membrane or the fluid diffusion layer. The composite may be dried to dry the solvent of the electrode ink to form a solid electrode layer. In embodiments where the electrodes are deposited onto the fluid diffusion layer, the electrolyzer composite membrane may be laminated to the electrode-fluid diffusion composite to form the MEA. For the avoidance of doubt, the backer must be removed from the electrolyzer composite membrane before applying the cathode. The ionomers in the ionomer solution used for each ionomer layer (also known as butter coat or BC) may be the same or different. The reinforcing layers used in the electrolyte composite membrane may all be the same, or at least one of the reinforcing layers may be different.

[0072] The present inventors have been working to solve the problem of low puncture resistance of state-of-the-art PEMs, as described above. As a result, it has been surprisingly found that increasing the content of reinforced microporous polymer structures in the polymer electrolyte membrane (PEM) continuously increases the puncture resistance. Surprisingly, this increase in reinforcement can be achieved without increasing the thickness of the PEM or increasing the amount of ionomer used.

[0073] Furthermore, the inventors have discovered that for a given total content of reinforced microporous polymer structures, providing the microporous polymer structures in a multi-layer arrangement (at least two layers) significantly improves the puncture resistance of a polymer electrolyte membrane (PEM) compared to a PEM comprising a microporous polymer structure provided in a single layer of comparable content.

[0074] Furthermore, the inventors have discovered that adding a recombination catalyst adjacent to (e.g., in contact with) the anode minimizes hydrogen crossover to the anode, and therefore allows thin electrolyzer PEMs to be safely used in the electrolyzer.

[0075] Providing a PEM that is highly resistant to puncture reduces the likelihood of electrolyzer failure due to short circuits that may occur if the composite membrane is punctured during assembly of the electrolyzer. It also reduces the risk of electrolyzer failure due to explosions caused by puncture of the PEM or hydrogen crossover to the anode. Reducing the occurrence of short circuits may also increase the life of devices manufactured with the membrane. Furthermore, providing a membrane that is highly resistant to puncture by other electrolyzer components without increasing the membrane thickness allows the ionic conductivity of the membrane to remain high, reducing manufacturing costs, since a thinner membrane requires less ionomer content to have the same percentage of reinforcement. The increased mechanical resistance of the thin electrolyzer composite membrane also allows the membrane to be stable at the higher operating temperatures and pressures experienced by electrolyzer PEMs. [Brief description of the drawings]

[0076] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] FIG. 1 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to an embodiment of the present disclosure. The electrolyzer composite membrane has two reinforcing layers, each reinforcing layer including a microporous polymer structure separated by an inner layer of ion exchange material, two outer layers of ion exchange material, a first outer top layer and a second outer bottom layer. The first outer top layer of ion exchange material and the reinforcing layer disposed adjacent to the first outer top layer of ion exchange material include a recombination catalyst (shown as dots) dispersed therein. The first outer top layer is configured to be disposed adjacent to an anode in an electrolyzer.

[0077] [Diagram 2]Figure 2 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. The electrolyzer composite membrane is similar to the electrolyzer composite membrane of Figure 1 and includes two reinforcement layers each comprising a microporous polymer structure separated by an inner layer of ion exchange material, a first outer upper layer and a second outer lower layer of two outer layers of ion exchange material. The first outer upper layer includes a recombination catalyst (shown as dots) and forms a recombination catalyst layer. The recombination catalyst layer is configured to be placed next to the anode in an electrolyzer. In this figure, the electrolyzer composite membrane is shown with a backer layer disposed on the second outer lower layer of ion exchange material.

[0078] [Diagram 3] Figure 3 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. The electrolyzer composite membrane is similar to the composite membrane of Figure 2, with two reinforcement layers each comprising a microporous polymer structure separated by an inner layer of ion exchange material, a first outer top layer and a first outer bottom layer of two outer layers of ion exchange material. The composite membrane includes an additional layer of recombination catalyst on the first outer top layer of ion exchange material. The recombination catalyst layer is configured to be placed next to the anode in the electrolyzer.

[0079] [Figure 4] Figure 4 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. The electrolyzer composite membrane is similar to the composite membrane of Figure 2, with two reinforcing layers, each comprising a microporous polymer structure, but in this embodiment, the reinforcing layers are in contact with each other without an inner layer of ion exchange material. The electrolyzer composite membrane includes two outer layers of ion exchange material, a first outer upper layer and a second outer lower layer. The first outer upper layer includes a recombination catalyst (shown as dots). The recombination catalyst layer is configured to be placed next to the anode in the electrolyzer.

[0080] [Diagram 5]FIG. 5 shows a cross-sectional view of an electrolyzer composite membrane according to another embodiment of the present disclosure. The electrolyzer composite membrane is similar to the composite membrane of FIG. 3, with two reinforcing layers, each of which comprises a microporous polymer structure, but in this case, the reinforcing layers are in contact with each other and there is no inner layer of ion exchange material. The electrolyzer composite membrane includes two outer layers of ion exchange material, a first outer upper layer and a second outer lower layer. The composite membrane includes an additional layer of recombination catalyst on the first outer upper layer of ion exchange material. The recombination catalyst layer is configured to be placed next to the anode in an electrolyzer. In this figure, an electrolyzer composite membrane is shown with a backer layer placed on the second outer lower layer of ion exchange material.

[0081] [Figure 6] FIG. 6 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. In this embodiment, the electrolyzer composite membrane has three reinforcing layers comprising a microporous polymer structure impregnated with ion exchange material. All three reinforcing layers are in direct contact with each other, and the electrolyzer composite membrane has two outer layers of ion exchange material disposed on opposite outer surfaces of the reinforcing layers. The first outer top layer of ion exchange material and the reinforcing layer disposed adjacent to the first outer top layer of ion exchange material include a recombination catalyst dispersed therein. The first outer top layer is configured to be disposed adjacent to the anode in an electrolyzer.

[0082] [Figure 7] Figure 7 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure, which is similar to the membrane of Figure 6, except that the first outer top layer of ion exchange material does not have the recombination catalyst, and the recombination catalyst is present as an additional layer disposed on the first outer top layer of ion exchange material.

[0083] [Figure 8]FIG. 8 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. In this embodiment, the electrolyzer composite membrane has three reinforcing layers each comprising a microporous polymer structure impregnated with an ion exchange material. The reinforcing layers are separated from each other by an inner layer of ion exchange material. The electrolyzer composite membrane has two outer layers of ion exchange material on the outer surfaces opposite the reinforcing layers. The first outer top layer includes a recombination catalyst (shown as dots) that forms a recombination catalyst layer. The recombination catalyst layer is configured to be disposed adjacent to the anode in the electrolyzer.

[0084] [Figure 9] FIG. 9 shows a schematic diagram of a cross section of an electrolyzer composite membrane according to another embodiment of the present disclosure. The composite membrane is similar to the composite membrane of FIG. 5, with three reinforcing layers each comprising a microporous polymer structure impregnated with an ion exchange material, the reinforcing layers being separated from each other by respective inner layers of ion exchange material. The electrolyzer composite membrane further comprises two outer layers of ion exchange material, a first outer upper layer and a second outer lower layer. The composite membrane comprises an additional layer of recombination catalyst on the first outer upper layer of ion exchange material. The recombination catalyst layer is configured to be disposed adjacent (i.e., next to) the anode in the electrolyzer. In this figure, an electrolyzer composite membrane is shown including a backer layer disposed on the second outer lower layer of ion exchange material.

[0085] [Figure 10] FIG. 10 illustrates a membrane electrode assembly including the electrolyzer composite membrane of FIG. 8, an anode disposed adjacent to the recombination catalyst layer, and a cathode disposed adjacent to the second outer sublayer of ion exchange material.

[0086] [Figure 11] FIG. 11 shows a schematic diagram of the chemical reactions occurring within an electrolyser and a basic schematic diagram of a membrane electrode assembly.

[0087] [Figure 12]Figure 12 shows a schematic diagram of a membrane electrode assembly (MEA) including an electrolyzer composite membrane similar to that of Figure 2, having two reinforcement layers separated by an inner layer of ion exchange material, two outer layers of ion exchange material, and a recombination catalyst layer disposed adjacent to the anode on one of the outer layers of ion exchange material, and a cathode on the other outer layer of ion exchange material. The diagram illustrates the flow of hydrogen cations and hydrogen gas through the membrane.

[0088] [Figure 13] Figure 13 shows a graph depicting the average puncture force (N) of the membranes of the examples shown in Table 1 versus the electrolyzer composite membrane thickness (μm) at 50% RH. The data points at about 80 μm correspond to Example 21 and Comparative Example 1, respectively, the data points at about 40 μm correspond to Example 2 and Comparative Example 2, respectively, and x corresponds to the commercial Nafion membranes N115, N212 and N211.

[0089] [Figure 14] FIG. 14 shows a graph representing the hydrogen crossover experienced in the electrolyzer using the commercial membrane Nafion™ N115 and the membranes of Examples 1, 2 and 3 of the present invention, measured by the Hydrogen Crossover Test defined herein at 55° C., current density of 0.5 A / cm2 and an anode differential pressure of 2 bar.

[0090] [Figure 15] Figure 15 shows Table 1 showing the properties of an exemplary electrolyzer composite membrane according to an embodiment of the present invention, a commercial electrolyzer composite membrane, and two comparative electrolyzer composite membranes. Table 1 also shows the puncture resistance and hydrogen crossover data of the examples.

[0091] [Figure 16] FIG. 16 shows Table 2 showing the properties of the microporous polymer structures used in the electrolyzer composite membranes of the examples.

[0092] [Figure 17]FIG. 17 shows a schematic diagram of an embodiment of a method for manufacturing an embodiment of an electrolyzer composite membrane of the present disclosure having reinforcement layers separated by internal ionomer layers, and an ionomer layer between the recombination catalyst and the reinforcement layer furthest from the backer (in other words, the reinforcement layer configured to be closest to the anode in use). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0093] Detailed Description The present application discloses an electrolyzer composite membrane for electrolyzers with improved mean rupture force and reduced hydrogen crossover compared to state-of-the-art composite membranes, which improves the resistance of the composite membrane to puncture by other components of the electrolyzer during device assembly and increases the lifetime of the PEM. Without being bound by theory, providing a composite membrane with at least two reinforcement layers, each of said at least two reinforcement layers including a microporous polymer structure, significantly contributes to improving the puncture resistance of the composite membrane compared to a composite membrane of similar thickness and content of microporous polymer structure provided in a single reinforcement layer. The inclusion of a recombination catalyst within the membrane minimizes hydrogen crossover occurring across the membrane, even for thin membranes, over a wide range of operating pressures.

[0094] In some embodiments, a composite membrane for an electrolytic device is provided that includes: a) at least two reinforcement layers, where each of the at least two reinforcement layers comprises a microporous polymer structure; and b) an ion exchange material (IEM) at least partially absorbed within the microporous polymer structure of the at least two reinforcement layers, rendering the microporous polymer structure occlusive; and c) a recombination catalyst, wherein said recombination catalyst is configured to be disposed closer to the anode than to the cathode of the electrolyzer composite membrane electrode assembly (MEA) or electrolyzer.

[0095] The composite membrane may have a thickness of at least about 20 μm at 50% RH. The microporous polymer structure may be present in a total amount of at least about 10% by volume, based on the total volume of the composite membrane.

[0096] The thickness of the electrolyzer composite membrane may be measured from a surface configured to be placed in contact with the cathode in use to a surface configured to be placed in contact with the anode in use. The location of the recombination catalyst layer within the electrolyzer composite membrane may be defined with reference to the thickness of the membrane and the outermost surface of the membrane that is in contact with the cathode and anode, respectively. The portion of the electrolyte composite membrane that is placed adjacent to the anode may be placed in contact with the anode. The recombination catalyst may be placed in contact with the anode. The electrolyzer composite membrane may have a recombination catalyst (e.g., a recombination catalyst layer) disposed on the outermost surface of the membrane and configured to contact the anode in use without other intervening layers. Although at least a portion of the recombination catalyst should be closer to the other in the MEA than to the cathode, the recombination catalyst may extend within the electrolyzer composite membrane. For example, the recombination catalyst may extend from the outermost surface of the membrane to about half the thickness of the membrane. The recombination catalyst may be present on the outermost surface of the membrane configured to be placed in contact with the anode and may be present within about 1% to about 75% of the thickness of the membrane. In some embodiments, the recombination catalyst may be configured to be disposed adjacent to the anode. The recombination catalyst may be configured to be in direct contact with the anode. In other embodiments, the recombination catalyst may be configured to be disposed in indirect contact with the anode (e.g., close to the anode, but with one or more intervening elements therebetween). In some embodiments, the recombination catalyst may be present in a separate layer. For example, the recombination catalyst may be mixed with an ionomer (and optionally a catalyst support) and disposed as a layer on the outermost surface of the electrolytic composite membrane, which is configured to contact the anode in use. The recombination catalyst may be dispersed within a portion of the thickness of the membrane. The recombination catalyst may be absorbed within at least one reinforcement layer of the electrolyzer composite membrane.

[0097] The embodiments are described using volume-based values ​​to provide a meaningful method of comparison between the compositions of the composite membranes including ionomers and the microporous polymer structures of different densities. The entire microporous polymer structure may be present in an amount of at least about 10 volume percent based on the total volume of the composite membrane.

[0098] Various definitions used in this disclosure are provided below.

[0099] As used herein, the terms "ionomer" and "ion exchange material" refer to cation exchange material, anion exchange material, or ion exchange material that contains both cation and anion exchange capacity. Mixtures of ion exchange materials can also be used. The ion exchange material can be perfluorinated or hydrocarbon-based. Suitable ion exchange materials include, for example, perfluorosulfonic acid polymers, perfluorocarboxylic acid polymers, perfluorophosphonic acid polymers, styrene-based ion exchange polymers, fluorostyrene-based ion exchange polymers, polyaryletherketone ion exchange polymers, polysulfone ion exchange polymers, bis(fluoroalkylsulfonyl)imides, (fluoroalkylsulfonyl)(fluorosulfonyl)imides, polyvinyl alcohol, polyethylene oxide, divinylbenzene, metal salts with or without polymers, and mixtures thereof. In an exemplary embodiment, the ion exchange material comprises a perfluorosulfonic acid (PFSA) polymer made by copolymerizing tetrafluoroethylene and perfluorosulfonyl vinyl ester to convert them to proton form.

[0100] As used herein, the "equivalent weight" of an ionomer or ion exchange material refers to the weight (molecular weight) of polymer in the ionomer per sulfonic acid group. Thus, a lower equivalent weight indicates a higher acid content. The equivalent weight (EW) of an ionomer refers to the EW when the ionomer is in the proton form at 0% RH and impurities are negligible. The term "ion exchange capacity" refers to the reciprocal of the equivalent weight (1 / EW).

[0101] As used herein, the "equivalent volume" of an ionomer or ion exchange material refers to the volume of ionomer per sulfonic acid group. The equivalent volume (EV) of an ionomer refers to the EV when the ionomer is pure, in the proton form at 0% RH, and contains negligible impurities.

[0102] As used herein, the term "microporous polymer structure" refers to a polymer matrix that supports the ion exchange material and adds structural integrity and durability to the resulting composite membrane. In some exemplary embodiments, the microporous polymer structure comprises expanded polytetrafluoroethylene (ePTFE) having a node and fibril structure. In other exemplary embodiments, the microporous polymer structure comprises a track-etched polycarbonate membrane having a smooth flat surface, high apparent density, and well-defined pore size. The microporous polymer structure is distributed between at least two (i.e., two or more) reinforcing layers. In other words, the electrolyzer composite membrane of the present disclosure comprises a microporous polymer structure present in two or more reinforcing layers.

[0103] As used herein, the interior volume of a microporous polymer structure is referred to as "substantially occluded" when the interior volume has a structure characterized by a low volume of voids of less than 10% by volume and is highly impermeable to gases at Gurley numbers of greater than 10,000 seconds. Conversely, the interior volume of a microporous polymer structure is referred to as "non-occluded" when the interior volume has a structure characterized by a high volume of voids of more than 10% by volume and is permeable to gases at Gurley numbers of less than 10,000 seconds.

[0104] composite membrane Figures 1-9 show schematic diagrams of electrolyzer composite membranes according to embodiments of the present disclosure. Similar features to the membrane of Figure 1 are indicated with the same reference numbers, increased by 100 to match the numbering of the figures. Figures 1, 2, 3, 4 and 5 show schematic diagrams of composite membranes 100, 200, 300, 400, 500 comprising an exchange material (e.g., ionomer) 110, 210, 310, 410, 510 and two reinforcement layers 105a,b, 205a,b, 305a,b, 405a,b, 505a,b with a microporous polymer structure. Each of the microporous polymer structures of the reinforcement layers 105a,b, 205a,b, 305a,b, 405a,b, 505a,b and 605a,b is impregnated (absorbed) with the ion exchange material 110, 210a,b, 310, 410, 510, 610, thus forming the occlusive reinforcement layers 104a,b, 204a,b, 304a,b, 404a,b and 504a,b. In other words, the ion exchange material 110, 210, 310, 410, 510, 610 can substantially impregnate the microporous polymer structure of the reinforcement layer so as to render the interior volume substantially occlusive (i.e., such that the interior volume has a structure characterized by a low volume of voids and high impermeability to gases). For example, by filling more than 90% of the internal volume of the microporous polymer structure of reinforcement layers 105a,b, 205a,b, 305a,b, 405a,b and 05a,b with ion exchange material 110, 210, 310, 410, 510, 610, substantial blockage occurs and the membrane is characterized by a Gurley number of more than 10000 seconds. In the embodiment according to Figures 1, 2 and 3-2, ion exchange material 110, 210, 310 is disposed on the inner and outer surfaces of the reinforcement layers, respectively, forming (unreinforced) ion exchange material layers 115, 215. In those embodiments, the ion exchange material, in addition to being impregnated into the microporous polymer structure of the two reinforcement layers, is also present disposed on one or more surfaces of the imbibed reinforcement layers in one or more additional ion exchange layers (i.e., non-reinforced ionomer or ion exchange material (IEM) layers) 115a,c, 215a,c, 315a,b,c, 415, 515a,b. In all of these embodiments, the different IEM layers within a given membrane can include the same ion exchange material as the imbibed layers 104a and 104b, 204a, 204b, 304a, 304b.Alternatively, the ion exchange material of one or both IEM layers (e.g., 115a and / or 115b and / or 115c) may be different from the ion exchange material of the absorber layers 104a and 104b. The ion exchange materials of both IEM layers 115a and 115b may be the same or different. In FIG. 1, the electrolyzer composite membrane 100 has an outer IEM layer 115b configured to be disposed adjacent to a cathode in a membrane electrode assembly (MEA). In this embodiment, an inner IEM layer 115c is also disposed between the two reinforcement layers 155a and 155b. The membrane 100 also has a recombination catalyst 120 disposed on the outermost surface of the membrane furthest from the IEM layer 115b. The recombination catalyst 120 partially penetrates into the first reinforcement layer 155a, as represented by discrete points. The recombination catalyst may be mixed with the ion exchange material, may be present in particulate form, and / or may include a support.

[0105] The membrane 200 of Figure 2 has a similar structure to the membrane 100 of Figure 1, but in this case the recombination catalyst is present as a separate layer 220 of recombination catalyst (e.g., mixed with an ionomer and optionally a support such as carbon black) disposed on top of the imbibed reinforcement layer 204a. Thus, the recombination catalyst particles are not imbibed within the microporous polymer structure of the reinforcement layer.

[0106] The membrane 300 of Figure 3 has a similar structure to the membrane 200 of Figure 2, with the recombination catalyst present in a separate layer 220, which is the outermost surface of the membrane and is configured to be placed adjacent to or in contact with the anode in an MEA, in use. However, in this embodiment, an additional IEM layer 315a is positioned between the recombination catalyst layer 320 and the first absorption enhancement layer 304a.

[0107] The electrolyzer composite membrane 400 of Figure 4 has a similar structure to the electrolyzer composite membrane 200 of Figure 2, except that the two imbibed reinforcing layers 404a and 404b are in direct contact without an intervening IEM layer. Similarly, the electrolyzer composite membrane 500 of Figure 5 has a similar structure to the electrolyzer composite membrane 300 of Figure 3, except that the two imbibed reinforcing layers 504a and 504b are in direct contact without an intervening IEM layer.

[0108] Figures 6-9 show an electrolyzer composite membrane with three reinforcing layers. Figure 6 shows an electrolyzer composite membrane 600 having a structure similar to membrane 400 of Figure 4, but in this case there are three imbibed reinforcing layers 604a, b and c that contact each other without an intervening IEM layer. A first outer top layer of ion exchange material and a reinforcing layer disposed adjacent to the first outer top layer of ion exchange material contain a recombination catalyst dispersed therein. The outer top layer containing the recombination catalyst is configured to be disposed adjacent to or in contact with an anode in an MEA or electrolyzer, with a portion of the recombination catalyst being imbibed within reinforcing layer 605a.

[0109] FIG. 7 shows an electrolyzer composite membrane 700 having a structure similar to membrane 300 of FIG. 3, but in this case there are three imbibed reinforcement layers 704a, b and c that contact each other without an intervening IEM layer.

[0110] FIG. 8 shows an electrolyzer composite membrane 800 having a structure similar to membrane 200 of FIG. 2, but in this case there are three imbibed reinforcement layers 704a, b, and c separated from one another by intervening (internal) IEM layers 815c and 815d, respectively.

[0111] Figure 9 shows an electrolyzer composite membrane 900 having a similar structure to membrane 300 of Figure 3, but in this case there are three imbibed reinforcement layers 804a, b, and c separated from one another by intervening (internal) IEM layers 915c and 915d, respectively. Membrane 900 also has two external IEM layers 915a (configured to face the anode) and 915d (configured to be placed adjacent to or in contact with the cathode). As with membrane 300, there is a separate layer of recombination catalyst 920 disposed on IEM layer 915a. Recombination catalyst layer 920 is configured to be placed adjacent to or in contact with the anode in an MEA or electrolyzer.

[0112] Although only shown in Figures 2 and 9, in all embodiments the electrolyzer composite membrane may be provided on a backer layer 250, 950. The backer layer 250, 950 may include a release film, such as a cycloolefin copolymer (COC) layer. In some embodiments, the electrolyzer composite membrane may be released (or separated) from the backer layer 250, 950 before being incorporated into a membrane electrode assembly (MEA).

[0113] Although not specifically shown, other embodiments of the composite membrane as described herein may include three or more absorbent layers, each of which includes a reinforcing layer that includes a microporous polymer structure and an ion exchange material absorbed or partially absorbed within the microporous polymer material. In some embodiments, the composite membrane may have only one external IEM layer on one of the composite membrane's exterior surfaces. In some embodiments, the composite membrane may have an IEM layer on both exterior surfaces of the absorbed layers and one or more internal IEM layers between at least two absorbed layers. In some embodiments, the composite membrane may have an internal IEM layer between each of the absorbed layers. In some embodiments, the composite membrane may have an internal IEM layer between each absorbed layer and a single external IEM layer on one of the composite membrane's exterior surfaces. In some embodiments, the composite membrane may have an internal IEM layer between each absorbed layer and a single external IEM layer on both exterior surfaces of the composite membrane. In all cases, the recombination catalyst (mixed with an ionomer and possibly also with a support such as carbon black) must be located closer to the anode than the MEA or cathode of the electrolyzer. In some embodiments, the recombination catalyst is disposed in direct or indirect contact with the anode.

[0114] The imbibed layers of the composite membrane may be constructed with reinforcing layers comprising two (or more) different microporous polymer structures. For example, referring to FIG. 1, a first imbibed layer 104a may be formed by imbibing a first microporous polymer structure 105a with an ion exchange material 110, and a second imbibed layer 104b may be formed by imbibing a second reinforcing layer 105b comprising a second microporous polymer structure with the same ion exchange material 110. In these embodiments, the first reinforcing layer 105a and the second reinforcing layer 105b are different (e.g., different porosity, different node and fibril structure, different thickness, etc.). The principles of using different types of reinforcing layers in a composite membrane construction may be applied to either illustrated embodiment. For example, in the embodiment according to FIG. 2, the first absorbent layer 204a can be formed by imbibing a first ion exchange material 210a into a first reinforcement layer 205a comprising a first microporous polymer structure, and the second absorbent layer 204b can be formed by imbibing a second ion exchange material 210b into a second reinforcement layer 205b comprising a second microporous polymer structure 205b. In these embodiments, the first reinforcement layer 205a and the second reinforcement layer 205b are different. Thus, in the composite membranes described herein and shown in the figures, the first microporous polymer structure may be the same or different from the second microporous polymer structure. The first ion exchange material may be the same or different from the second ion exchange material.

[0115] In embodiments (as shown) in which the composite membrane includes an internal IEM layer between at least two reinforcement layers, the at least two reinforcement layers can be separated by a distance d. The distance d can be from about 1 μm to about 12 μm. The distance d can be from about 2 μm to about 8 μm. The distance d can be from about 4 μm to about 6 μm. The distance d can be from about 1 μm to about 5 μm. The distance d can be from about 5 μm to about 10 μm. The distance d can be from about 6 μm to about 8 μm. The distance d can be about 1 μm, or about 2 μm, or about 3 μm, or about 4 μm, or about 5 μm, or about 6 μm, or about 7 μm, or about 8 μm, or about 9 μm, or about 10 μm. The distance d can be the thickness of the internal IEM layer (i.e., the layer of unreinforced ion exchange material disposed between two adjacent reinforcement layers).

[0116] Figure 10 shows an electrolyzer membrane electrode assembly 1100 according to an embodiment of the present disclosure. The MEA 1100 has an electrolyzer composite membrane 800 as shown in Figure 8, an anode 1110 disposed in contact with the recombination catalyst layer 820 of the membrane 800, and a cathode 1120 disposed in contact with the outer surface of the membrane (external IEM 915b) furthest from the recombination catalyst 820.

[0117] Figure 11 shows a schematic of the electrochemical reactions that occur within the electrolyzer. At the anode, water is oxidized to form molecular oxygen and protons. The protons produced at the anode can permeate through the electrolyzer composite membrane to the cathode, where they are reduced to molecular hydrogen.

[0118] FIG. 12 is a schematic diagram of the crossover that occurs across an electrolyzer composite membrane electrode assembly (electrolyzer MEA) 1200, which includes an electrolyzer composite membrane 1250 similar to membrane 200 of FIG. 2, an anode 1210 disposed in contact with a recombination catalyst layer 1252 of the membrane 1250, and a cathode 1220 disposed in contact with the outer surface of the membrane 1250 furthest from the recombination catalyst layer 1252. Molecular hydrogen should not migrate through the electrolyte composite membrane, but there is a small percentage that manages to cross over from the anode to the cathode. The extent of crossover hydrogen should be minimized, and the inventors have surprisingly discovered that locating the recombination catalyst 1252 closer to the anode 1210 than to the cathode 1220 allows the membrane 1250 to keep the electrolyte composite membrane as thin as possible (e.g., about 20 μm to about 250 μm thick at 50% RH). Approximately 0.01 g (metal) / cm 2 Even low recombination catalyst loadings of less than 10000000000000 are sufficient to catalyze the oxidation of molecular hydrogen back to protons, thus minimizing the risk of explosion at the anode.

[0119] Microporous polymer structure The composite membrane can have at least two reinforcing layers, each of which includes a microporous polymer structure.

[0120] A composite membrane can have two or more reinforcement layers comprising a microporous polymer structure, for example, a composite membrane can have 2, 3, 4, 5, 6, 7, 8, 9 or 10 reinforcement layers, each of which comprises a microporous polymer structure.

[0121] The appropriate microporous polymer structure will depend largely on the application the composite membrane will be used in. The microporous polymer structure preferably has good mechanical properties, is chemically and thermally stable in the environment in which the composite membrane will be used, and is resistant to any additives used with the ion exchange material for impregnation.

[0122] As used herein, the term "reinforcement layer comprising a microporous polymer structure" is intended to refer to a layer having a thickness of at least about 10 μm, possibly about 10 μm to about 230 μm, or about 10 μm to about 100 μm, or about 10 μm to about 50 μm, and having an average pore size of about 0.05 μm to about 20 μm, for example, 0.1 μm to 1 μm. According to various optional embodiments, the pores can have an average pore size of 0.01 to 100 microns, for example, 0.05 to 20 microns, or 0.1 to 1 micron. Suitable microporous polymer structures of the reinforcement layer for electrolysis device applications can include porous polymer materials. The porous polymeric material may include fluoropolymers, chlorinated polymers, hydrocarbons, polyamides, polycarbonates, polyacrylates, polysulfones, copolyetheresters, polyethylene, polypropylene, polyvinylidene fluoride, polyaryletherketones, polybenzimidazoles, poly(ethylene-co-tetrafluoroethylene), poly(tetrafluoroethylene-co-hexafluoropropylene). In some embodiments, the microporous polymeric structure 105, 205, 305, 405, 505, 6605, 705 comprises a perfluorinated porous polymeric material. The perfluorinated porous polymeric material may include polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyvinylidene fluoride (PVDF), expanded polyvinylidene fluoride (ePVDF), expanded poly(ethylene-co-tetrafluoroethylene) (eEPTFE), or mixtures thereof.

[0123] In some embodiments, the microporous polymer structure comprises a hydrocarbon material, which may include polyethylene, expanded polyethylene, polypropylene, expanded polypropylene, polystyrene, polycarbonate, track-etched polycarbonate, or mixtures thereof. Examples of perfluorinated porous polymeric materials suitable for use in electrochemical applications include ePTFE, manufactured according to the teachings of U.S. Patent No. 8,757,395, which is incorporated herein by reference in its entirety, and is commercially available in various forms from W. L. Gore & Associates, Inc. (Elkton, Maryland).

[0124] In embodiments in which the microporous polymer structure comprises ePTFE, the total mass (mass per area) of the microporous polymer structure within the electrolyzer composite membrane is about 8 g / m, based on the total area of ​​the composite membrane. 2 ~about 80g / m 2 , about 8g / m 2 ~about 70g / m 2 , or about 8 g / m 2 ~about 60g / m 2 , or about 8 g / m 2 ~about 60g / m 2 , or about 8 g / m 2 ~about 50g / m 2 , or about 8 g / m 2 ~about 40g / m 2 , or about 8 g / m 2 ~Approx. 35g / m 2 , or about 8 g / m 2 ~About 30g / m 2 , or about 8 g / m 2 ~about 20g / m 2 , or about 8 g / m 2 ~about 15g / m 2 The total mass per area of ​​the microporous polymer structure can be about 8 g / m, based on the total area of ​​the composite membrane. 2 ~About 30g / m 2 The total mass per area of ​​the microporous polymer structure can be about 10 g / m, based on the total area of ​​the composite membrane. 2 ~about 15g / m 2The total content (mass per area) of the microporous polymer structure in the electrolyzer composite membrane can be about 20 g / m, based on the total area of ​​the composite membrane. 2 ~about 80g / m 2 , or about 30 g / m 2 ~about 70g / m 2 , or about 20 g / m 2 ~about 50g / m 2 , or about 30 g / m 2 ~about 60g / m 2 It can be.

[0125] Ion Exchange Materials Suitable ion exchange materials may depend on the application in which the composite membrane is used. The ion exchange material preferably has an average equivalent volume of about 240cc / molar equivalent to about 870cc / molar equivalent, optionally about 240cc / molar equivalent to about 650cc / molar equivalent, optionally about 350cc / molar equivalent to about 475cc / molar equivalent, and is chemically and thermally stable in the environment in which the composite membrane is used. Ionomers suitable for fuel cell applications may include ion exchange materials such as cation exchange materials, anion exchange materials, or ion exchange materials that include both cation exchange and anion exchange capabilities. In some embodiments, the ion exchange material includes a proton conducting polymer or a cation exchange material. The ion exchange material can be perfluorocarboxylic acid polymers, perfluorophosphonic acid polymers, styrenic ion exchange polymers, fluorostyrene-based ion exchange polymers, polyaryletherketone ion exchange polymers, polysulfone ion exchange polymers, bis(fluoroalkylsulfonyl)imides, (fluoroalkylsulfonyl)(fluorosulfonyl)imides, polyvinyl alcohol, polyethylene oxide, divinylbenzene, metal salts with or without polymers, and mixtures thereof. Examples of perfluorosulfonic acid polymers suitable for use in fuel cell applications include Nafion® (EI DuPont de Nemours, Inc., Wilmington, Delaware, USA), Flemion® (Asahi Glass Co., Ltd., Tokyo, Japan), Aciplex® (Asahi Chemical Co., Ltd., Tokyo, Japan), Aquivion® (SolvaySolexis SPA, Italy) and 3M™ (3M Innovative Properties Company, USA), which are commercially available perfluorosulfonic acid copolymers. Other examples of perfluorosulfonic acid polymers suitable for use in fuel cell applications include perfluorinated sulfonyl (co)polymers, such as those described in U.S. Pat. No. 5,463,005.

[0126] Composite membrane properties As mentioned above, the composite membrane comprises a microporous polymer structure and an ion exchange material absorbed in the microporous polymer structure, thereby forming two distinct materials that improve the puncture resistance of the composite membrane. Without being bound by theory, the puncture resistance of the composite membrane can be influenced by the distribution of the total content of the microporous polymer structure in the multiple (i.e., at least two) reinforcement layers, compared to the same content of the microporous polymer structure provided in a single reinforcement layer in the structure of the composite membrane. Furthermore, the puncture resistance of the composite membrane can be influenced by the total content of the microporous polymer structure in the composite membrane.

[0127] The composite membrane has a thickness of at least about 20 μm at 50% RH, for example, about 20 μm to about 250 μm, or about 120 μm to about 250 μm, preferably about 20 μm to about 120 μm, or about 20 μm to about 110 μm, or about 20 μm to about 100 μm, or about 20 μm to about 90 μm, or about 20 μm to about 80 μm, or about 20 μm to about 70 μm, or about 20 μm to about 60 μm, or about 20 μm to about 50 μm, or about 20 μm to about 40 μm, or about 20 μm to about 30 μm, or It can have a thickness of about 25 μm to about 30 μm, or about 30 μm to about 55 μm, or about 30 μm to about 45 μm, or about 30 μm to about 35 μm, or about 40 μm to about 60 μm, or about 45 μm to about 55 μm, or about 50 μm to about 60 μm, or about 50 μm to about 120 μm, or about 60 μm to about 120 μm, or about 70 μm to about 100 μm, or about 80 μm to about 100 μm, or about 90 μm to about 120 μm, or about 100 μm to about 120 μm. The composite membrane can have a thickness at 50% RH of about 20 μm, or about 25 μm, or about 30 μm, or about 35 μm, or about 40 μm, or about 45 μm, or about 50 μm, or about 55 μm, or about 60 μm, or about 65 μm, or about 70 μm, or about 75 μm, or about 80 μm, or about 85 μm, or about 90 μm, or about 95 μm, or about 100 μm, or about 105 μm, or about 110 μm, or about 120 μm, or about 150 μm, or about 200 μm, or about 220 μm, or about 250 μm.

[0128] The total content of the microporous polymer structures (i.e., the sum of the volumes of the microporous polymer structures occupied by each reinforcing layer in the reinforcing structure) accounts for at least about 10% by volume based on the total volume of the composite membrane. For example, the total volume of the microporous polymer structures in the composite membrane can be about 10% by volume to about 80% by volume, or about 20% by volume to about 80% by volume, or about 30% by volume to about 80% by volume, or about 40% by volume to about 80% by volume, or about 50% by volume to about 80% by volume, or about 65% by volume to about 80% by volume, or about 25% by volume to about 60% by volume, or about 20% by volume to about 50% by volume, or about 20% by volume to about 40% by volume, or about 20% by volume to about 30% by volume, or about 40% by volume to about 60% by volume, or about 40% by volume to about 50% by volume based on the total volume of the composite membrane. The microporous polymer structure may be present at about 10% by volume, or about 15% by volume, or about 20% by volume, or about 25% by volume, or about 30% by volume, or about 35% by volume, or about 40% by volume, or about 45% by volume, or about 50% by volume, or about 55% by volume, or about 60% by volume, or about 65% by volume, or about 70% by volume, or about 80% by volume, based on the total volume of the electrolyzer composite membrane.

[0129] Each of the at least two reinforcing layers of the reinforcing structure has a strength of at least 4 g m -2 Each of the at least two reinforcing layers of the reinforcing structure may have a microporous polymer structure content of about 4 g m based on the total area of ​​the composite membrane. -2 ~Approx. 75g m -2 , or about 4 g m -2 ~Approx. 60g m -2 , or about 4 g m -2 ~Approx. 50g m -2 , or about 4 g m -2 ~Approx. 40g m -2 , or about 4 g m -2 ~Approx. 30g m -2 , or about 4 g m -2 ~Approx. 20g m -2 , or about 4 g m -2 ~Approx. 10g m -2 , or about 10 g m -2 ~Approx. 70g m -2 , or about 15 g m -2 ~Approx. 60g m-2 , or about 20 g m -2 ~Approx. 40g m -2 , or about 50 g m -2 ~Approx. 75g m -2 , or about 10 g m -2 ~Approx. 50g m -2 , or about 20 g m -2 ~Approx. 60g m -2 , or about 60 g m -2 ~Approx. 75g m -2 , or about 10 g m -2 ~Approx. 40g m -2 The microporous polymer structure may have a content of

[0130] In some embodiments, the equivalent volume of the ion exchange material is from about 240 cc / molar equivalent to about 870 cc / molar equivalent. The ion exchange material is from about 400 g / molar equivalent to about 2000 g / molar equivalent of SO3 - The total equivalent weight (EW) of the mixture may be:

[0131] In various embodiments, the acid content of the composite membrane is greater than 1.2 meq / cc at 0% relative humidity, for example, between 1.2 meq / cc and 3.5 meq / cc.

[0132] In various embodiments, the thickness of the composite membrane is from about 20 μm to about 250 μm, preferably from about 20 μm to about 120 μm. Specifically, according to embodiments, the thickness of the composite membrane is from about 20 μm to about 120 μm, while the acid content of the composite membrane is maintained at 1.2 meq / cc to 3.5 meq / cc.

[0133] The volume % of the microporous polymer structure in the composite membrane refers to the space occupied by the microporous polymer structure relative to the total volume of the electrolyzer composite membrane. Therefore, the volume % of the microporous polymer structure in the composite is different from the volume % of only the absorbing layer containing the ionomer. The volume % of the microporous polymer structure in the composite is affected by humidity. The measurements described below regarding volume % are performed under dry conditions (e.g., 0% relative humidity (RH)).

[0134] As shown above, it is surprising and unexpected that for any given content of microporous polymer structure and thickness of the composite membrane, the puncture resistance of the composite membrane is dramatically improved by distributing the content of the microporous polymer structure in two or more reinforcing layers.

[0135] The electrolyzer composite membrane can have an average puncture breaking force of at least about 60 gF (0.59 N) when measured according to the Average Puncture Force Breakdown Test described below. For example, the composite membrane can have an average puncture force of at least about 60 gF (0.59 N), or at least about 65 gF (0.64 N), or at least about 70 gF (0.69 N), or at least about 75 gF (0.74 N), or at least about 80 gF (0.78 N), or at least about 90 gF (0.88 N) when measured according to the Average Puncture Force Breakdown Test described below.

[0136] The electrolyzer composite membrane can have an average breaking force of about 60 gF (0.59 N) to about 160 gF (1.57 N), or about 60 gF (0.59 N) to about 80 gF, or about 60 gF to about 80 gF, or about 60 gF to about 75 gF, or about 60 gF to about 70 gF, or about 70 gF to about 90 gF, or about 80 gF to about 90 gF, or about 65 gF to about 75 gF, when measured according to the Average Puncture Force Break Test described below.

[0137] The electrolyzer composite membrane can have an average puncture force of about 60 gF, or about 65 gF, or about 70 gF, or about 75 gF, or about 80 gF, or about 85 gF, or about 90 gF, as measured by the Average Puncture Force Puncture Test described below.

[0138] The electrolyzer composite membrane was placed at 55°C and 0.5A / cm 2 At 55° C. and 0.5 A / cm 2 , the electrolyzer composite membrane can experience about 2% or less, or preferably 1% or less, hydrogen crossover, as measured by the hydrogen crossover detection method described herein, at an operating differential pressure in the range of 2 to 30 bar. 2and at an operating differential pressure in the range of 2 to 30 bar, may experience about 0% to about 2%, or about 0% to about 1%, or about 0.2% to about 1%, or about 0.3% to about 1%, or about 0.3% to about 0.9%, or about 0.5% to about 1%, or about 0.5% to about 1.5%, or about 1% to about 2%, or about 1.5% to about 2%, or about 0.6% to about 1.2% hydrogen crossover when measured by the hydrogen crossover detection methods described herein.

[0139] Membranes were prepared by a sequential coating process. For a membrane having an inner layer of ionomer between reinforcing layers, method 1500 (FIG. 17) included the following steps: 1510) Providing a backer layer and coating the backer with a first ionomer by depositing a liquid layer of a first ionomer solution; 1520) depositing a first reinforcing layer comprising a microporous polymer structure onto the liquid layer of ionomer such that the first ionomer solution is absorbed or at least partially absorbed into the microporous polymer structure of the first reinforcing layer; 1530) Optionally, dry the laminate; 1540) coating the imbibed first reinforcing layer with a liquid layer of a second ionomer solution; 1550) depositing a second reinforcement layer comprising a microporous polymer structure onto the liquid layer of the second ionomer solution such that the second ionomer is imbibed or at least partially imbibed into the microporous polymer structure of the second reinforcement layer; 1560) Optionally, dry the laminate; 1570) coating the outermost surface of the laminate furthest from the backer with a final liquid layer of a third ionomer solution mixed with a recombination catalyst such that the microporous polymer structure is at least partially imbibed with the ionomer; and 1580) Drying the laminate; Includes.

[0140] Optionally, the method includes repeating steps 1560), 1570) and 1580) with additional reinforcing layers and liquid layers of ionomer and drying the laminate. For example, in an electrolyzer composite membrane including three reinforcing layers, a third liquid layer of a third ionomer solution can be deposited on the imbibed second reinforcing layer, a third reinforcing layer can be applied on top of the third layer of ionomer solution, and the laminate can then be dried. In some embodiments, the method includes adding additional ionomer and reinforcing layers and drying the laminate.

[0141] The recombination catalyst may be mixed with the ionomer prior to deposition on the laminate. In some embodiments, the recombination catalyst may include a precious metal (e.g., Pt) on a support (e.g., carbon particles) mixed with the ionomer. A portion of the recombination catalyst may be absorbed within the outermost reinforcement layer, but in any case, at least a portion of the recombination catalyst should be located closer to the anode side than to the cathode side.

[0142] The membrane electrode assembly may be prepared by depositing an anode on the surface of the electrolyzer composite membrane having the recombination catalyst and depositing a cathode on the opposite surface of the electrolyzer composite membrane (i.e., the surface without the recombination catalyst).

[0143] The electrodes (i.e., anode and cathode) may be deposited by any suitable technique known in the art. For example, a solid electrode layer may be pressed onto the electrolyzer composite membrane by any suitable technique. Alternatively, a (liquid) electrode ink may be applied onto the electrolyzer composite membrane. When the composite is dried, the solvent of the electrode ink may dry to form a solid electrode layer. For the avoidance of doubt, the backer must be removed from the electrolyzer composite membrane before applying the cathode or cathode gas diffusion layer. The ionomers in the ionomer solution used for each ionomer layer (also known as butter coat) may be the same or different. The reinforcing layers used in the electrolyte composite membrane may all be the same, or at least one of the reinforcing layers may be different. EXAMPLES

[0144] example Test Procedures and Measurement Protocols Used in the Examples Bubble Point Bubble point was measured according to the procedure of ASTM F316-86. Isopropyl alcohol was used as the wetting fluid to fill the pores of the specimen. The bubble point is the pressure of air required to produce a first continuous stream of bubbles detectable by the bubbles rising through a layer of isopropyl alcohol covering a microporous polymer matrix. This measurement provides an estimate of the maximum pore size.

[0145] Non-contact thickness A sample of the microporous polymer structure was placed on a flat, smooth metal anvil and tensioned to remove wrinkles. The height of the microporous polymer structure on the anvil was measured and recorded using a non-contact Keyence LS-7010M digital micrometer. The height of the anvil without the microporous polymer matrix was then recorded. The thickness of the microporous polymer structure was taken as the difference between the micrometer readings with and without the microporous structure on the anvil.

[0146] Mass per area Each microporous polymer structure was strained sufficiently to eliminate wrinkles and then cut using a die to a length of 10 cm. 2 A small piece of 10cm was cut off. 2 The weight of the pieces was measured on a conventional laboratory scale. The mass per area (M / A) was then calculated as the ratio of the measured mass to the known area. This procedure was repeated twice and the average M / A was calculated.

[0147] Apparent density of microporous polymer structures The apparent density of the microporous polymer structure was calculated using the non-contact thickness and mass per area data using the following formula:

number

[0148] Porosity of microporous polymer structures The porosity of the microporous polymer structure was calculated using the apparent density and skeletal density data using the following formula:

number

[0149] Solids concentration of the ion exchange material (IEM) solution In this specification, the terms "solution" and "dispersion" are used interchangeably when referring to ion exchange materials (IEMs). This test procedure is appropriate for solutions in which the IEMs are in the proton form and other solids are present in negligible amounts. A volume of 2 cubic centimeters of IEM solution was drawn into a syringe and the mass of the syringe containing the solution was measured by the balance of a solids analyzer (obtained from CEM Corporation, USA). The mass of two sheets of glass fiber paper (obtained from CEM Corporation, USA) was also measured and recorded. The IEM solution was then deposited from the syringe onto two layers of glass fiber paper. The glass fiber paper containing the ionomer solution was placed in the solids analyzer and heated to 160°C to remove the solvent liquid. The mass of the glass fiber paper and the residual solids was recorded once it stopped changing with increasing temperature and time. The residual IEM is assumed to be water-free (i.e., this is the mass of the ionomer corresponding to 0% RH). The mass of the empty syringe was then measured using the same balance as before and recorded. The ionomer solids content in the solution was calculated according to the following formula:

number

[0150] Equivalent weight (EW) of IEM The following test procedure is appropriate for IEMs containing a single ionomer resin or a mixture of ionomer resins that are in the proton form (i.e., containing negligible amounts of other cations) and in solution containing negligible amounts of other cationic species, including protonic acids and dissociated salts. If these conditions are not met, the ionic impurities must be purified from the solution prior to testing according to appropriate procedures known to those skilled in the art, or the impurities must be characterized and their effect on the results of the EW test corrected.

[0151] As used herein, the EW of an IEM refers to when the IEM is in proton form at 0% RH with negligible impurities. The IEM may comprise a single ionomer or a mixture of ionomers in proton form. An amount of IEM solution having a solids concentration determined as above and containing 0.2 grams of solids was poured into a plastic cup. The mass of the ionomer solution was measured via a conventional laboratory scale (obtained from Mettler-Toledo, USA). Next, 5 ml of deionized water and 5 ml of 200 proof denatured ethanol (SDA 3C, Sigma Aldrich, USA) are added to the ionomer solution in the cup. Then, 55 ml of 2N aqueous sodium chloride solution was added to the IEM solution. The sample was then allowed to equilibrate under constant stirring for 15 minutes. After the equilibration step, the sample was titrated with 1N sodium hydroxide solution. The amount of 1N sodium hydroxide solution required to neutralize the sample solution to a pH value of 7 was recorded. The EW of the IEM (EW IEM ) was calculated as follows:

number

[0152] When multiple IEMs were combined to form a composite membrane, the average EW of the IEMs in the composite membrane was calculated using the following formula:

number

[0153] Equivalent Volume (EV) of Ion Exchange Material As used herein, the equivalent volume of an IEM refers to the EV when the IEM is pure and in its proton form at 0% RH with negligible impurities. The EV was calculated according to the following formula:

number

[0154] The equivalent weight of each IEM was determined according to the procedure described above. The IEM used in these applications was a perfluorosulfonic acid ionomer resin, and the bulk density of the perfluorosulfonic acid ionomer resin was 1.9 g / cc at 0% RH.

[0155] Composite membrane thickness The composite film was equilibrated in the thickness measurement chamber for at least 1 hour before the thickness was measured. The composite film was left attached to the composite film coated substrate. For each sample, the composite film on the coated substrate was placed on a smooth, flat, and level marble slab. A thickness gauge (obtained from Heidenhain Corporation, USA) was contacted to the composite film and height readings of the gauge were recorded at six different spots arranged in a grid pattern on the film. The sample was then removed from the substrate and the gauge was contacted to the substrate and height readings were again recorded at the same six spots. The thickness of the composite film at a given relative humidity (RH) in the chamber was calculated as the difference between the gauge height readings with and without the composite film present. The local RH was measured using a RH probe (obtained from Fluke Corporation). The thickness at 0% RH was calculated using the following general formula:

number

number

[0156] Microporous polymer structure (MPS) volume content of composite membranes The volume percent of the microporous polymer structure in each composite membrane was calculated according to the following formula:

number

[0157] Acid content of composite membrane The acid content of the composite membrane was calculated according to the following formula:

number

[0158] Ball burst testing of composite membrane microporous layers. The mechanical strength of the composite membranes prepared according to the present invention was measured by applying a load pressure to the samples. The sample was fixed in a taut state in a frame with an opening of 45 mm in diameter. The sample in the frame was placed in a Shimadzu universal testing machine AG-I, Japan, equipped with an environmental control chamber where the temperature and relative humidity in the chamber were 23°C and 80%, respectively. A steel ball with a diameter of 6.35 mm supported by a support was pressed into the suspended membrane at a constant speed of 100 mm / min. The maximum load generated by the system at the time of sample rupture was recorded, and this value is referred to as the ball burst strength.

[0159] Average puncture force destruction test A texture analyzer (Stable Micro Systems TA XT plus) is used to drive a puncture probe (Becton Dickinson 18G 1-1 / 2 PrecisionGlide Needle) into the membrane until the probe penetrates the sample. The membrane is fixed to a carbon felt (e.g., Sigracell GFD 4.6EA) and the membrane is supported by the felt and exposed to the puncture probe. The puncture probe is driven at a speed of 0.1 mm / s while measuring the force at the corresponding probe displacement. The puncture force is the maximum force observed before the sample mechanically fails and the force drops sharply. Values ​​reported are the average of five replicate tests.

[0160] Hydrogen Crossover Test Hydrogen crossover in the examples was measured by gas chromatography with a TCD detector (detection limit 10 ppm). Examples of electrolyser composite membranes were measured by TNO (Netherlands Organisation for Applied Scientific Research) at 55°C, 0.5 A / cm 2 Hydrogen crossover was tested in a custom-built electrolyser cell under fixed operating conditions and electrode pressure differentials ranging from 2 to 30 bar. Hydrogen crossover was measured by increasing the pressure difference between the cathode and anode by 2 bar every 30 minutes at the cathode.

[0161] example The composite membranes of the present disclosure may be better understood with reference to the following non-limiting examples. The properties of the composite membranes, such as acid content, volume and puncture resistance, as well as the test procedures and measurement protocols, were determined as described above. Table 1 (FIG. 15) shows the electrolyzer composite membrane properties of Examples 1, 2 and 3 according to the embodiments of the present invention, as well as Comparative Examples 1, 2 and commercial membranes Nafion™ N115, N212 and N211 (Chemours).

[0162] All examples are ion exchange materials made according to aspects of the present disclosure. All ion exchange materials used in the following examples are perfluorosulfonic acid (PFSA) based ionomers with the equivalent weight (EW) specified in Table 1. All ionomers prior to fabrication of the composite membranes were in the form of solutions based on a mixture of water and ethanol as the solvent with a water content of less than 50% in the solvent phase.

[0163] The composite membrane of the present disclosure was produced using a commonly known ion exchange material. A preferred example is a solution obtained by dispersing or dissolving a solid PFSA ionomer represented by the following general formula (a:b=1:1 to 9:1, n=0, 1 or 2) in a solvent. [ka] In some embodiments, the solvent is selected from the group consisting of water, alcohols such as methanol, ethanol, propanol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol, pentanol and its isomers, hexanol and its isomers, hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, formamide solvents such as N,N-dimethylformamide and N,N-diethylformamide, acetamide solvents such as N,N-dimethylacetamide and N,N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, 1,1,2,2-tetrachloroethane, 1,1,1,2-tetrachloroethane, 1,1,1-trichloroethane, 1,2-dichloroethane, trichloroethylene, tetrachloroethylene, dichloromethane, and chloroform. In the present disclosure, the solvent is optionally selected from the group consisting of water, methanol, ethanol, and propanol. Water and the above solvents may be used alone or in combination of two or more.

[0164] Invention Example 1 Inventive Example 1 was prepared according to the following procedure: Weight per area: about 10 g / m 2Type 1 ePTFE membrane (ePTFE 1 in Tables 1 and 2) with a thickness of 14 μm, apparent density of 0.16 g / cc, and bubble point of 56.2 psi was used for all reinforcing layers. EW = 710 g / mol equivalent of SO3 -A PSFA solution as the IEM (obtained from EI du Pont de Nemours and Company) with an IEM solution composition of 36% water, 47% ethanol, and 17% solids was coated as a first laydown on top of the backer layer. The backer layer (obtained from Daicel Value Coating Co., Ltd., Japan) contained a protective layer of PET and cyclic olefin copolymer (COC) and was oriented with the COC side up. The coating was done using a drawdown bar with a theoretical wet coating thickness of about 215 μm. While the coating was still wet, a first reinforcing layer of ePTFE membrane restrained in a metal frame was laminated to the IEM laydown, allowing the IEM solution to be absorbed into the pores of the first ePTFE membrane. This first intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. Upon drying, the microporous polymer structure of the first ePTFE membrane was completely absorbed with the IEM. A second laydown of the same IEM solution was coated onto the top surface of the first intermediate composite (the surface opposite the backer layer) using a drawdown bar with a theoretical wet coating thickness of about 215 μm. A second reinforcing layer of ePTFE membrane pre-restrained on a metal frame was laminated to the second IEM laydown while the coating was still wet, and the IEM solution was absorbed into the pores of the second ePTFE membrane. This second intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. A third laydown of the same IEM solution was coated onto the top surface of the second intermediate composite using a drawdown bar with a theoretical wet coating thickness of about 215 μm. A third reinforcing layer of ePTFE membrane pre-restrained on a metal frame was laminated to the third IEM laydown while the coating was still wet, and the IEM solution was absorbed into the pores of the third ePTFE membrane. This third intermediate composite was then dried in a convection oven with air inside at a temperature of 125° C. Recombination catalyst of Pt on carbon 0.085 mg / cm 2A fourth laydown of the same solution of IEM mixed with 100% ethylene glycol was coated on top of the third intermediate composite using a drawdown bar with a theoretical wet coating thickness of about 150 μm. This final composite was then dried in a convection oven at 165°C with air inside. The multilayer composite membrane was fully occluded and comprised a layer of IEM on each outer side and between each of the three fully occluded reinforcement layers with a separation distance of about 10-12 μm. Additionally, one of the outer IEM layers was a recombination catalyst layer formed as the outermost layer. The resulting electrolyzer composite membrane had a thickness of 80-90 μm at 50% RH.

[0165] Invention Example 2 Inventive Example 2 was prepared according to the following procedure. ePTFE membrane type 1 as described in Inventive Example 1 was used for all reinforcing layers. EW=710 g / mol equivalent of SO3 -A PSFA solution as the IEM (obtained from EI du Pont de Nemours and Company) with an IEM solution composition of 36% water, 47% ethanol, and 17.0% solids was coated as a first laydown on top of the backer layer. The backer layer (obtained from Daicel Value Coating Co., Ltd., Japan) contained a protective layer of PET and cyclic olefin copolymer (COC) and was oriented with the COC side up. Coating was performed using a drawdown bar with a theoretical wet coating thickness of about 115 μm. While the coating was still wet, a first reinforcing layer of ePTFE membrane pre-restrained on a metal frame was laminated to the IEM laydown, and the IEM solution was absorbed into the pores of the first ePTFE membrane. This first intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. Upon drying, the microporous polymer structure of the first ePTFE membrane was completely absorbed into the IEM. A second laydown of the same IEM solution was coated onto the top surface of the first intermediate composite membrane (the surface opposite the backer layer) using a drawdown bar with a theoretical wet coating thickness of about 150 μm. A second reinforcing layer of ePTFE membrane pre-restrained on a metal frame was laminated to the second IEM laydown while the coating was still wet, and the IEM solution was absorbed into the pores of the second ePTFE membrane. This second intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. A third laydown of the same solution of IEM was coated onto the top surface of the second intermediate composite using a drawdown bar with a theoretical wet coating thickness of about 150 μm. A third reinforcing layer of ePTFE membrane pre-restrained on a metal frame was laminated to the third IEM laydown while the coating was still wet, and the IEM solution was absorbed into the pores of the third ePTFE membrane. This third intermediate composite was then dried in a convection oven with air inside at a temperature of 125° C. Recombination catalyst of Pt on carbon 0.04 mg / cm 2A fourth laydown of the same solution of IEM mixed with was coated onto the top surface of the third intermediate composite using a drawdown bar with a theoretical wet coating thickness of about 66 μm. This final composite was then dried in a convection oven at 165 °C with air inside. The multilayer composite membrane was fully occluded with a layer of IEM on each outside and between each of the three fully occluded reinforcement layers with a separation spacing of about 2-4 μm. In addition, one outer layer of IEM forms the recombination catalyst. The resulting composite membrane had a thickness of about 40-50 microns at 50% RH.

[0166] Invention Example 3 Inventive Example 3 was prepared according to the following procedure: Weight per area: about 29 g / m 2 A type 2 ePTFE membrane (ePTFE2 in Tables 1 and 2) having a thickness of 29 μm, an apparent density of 0.22 g / cc, and a bubble point of 43.5 psi was used as the reinforcing layer. EW=710 g / mol equivalent SO3 -A PSFA solution as the IEM (obtained from EI du Pont de Nemours and Company) with an IEM solution composition of 38.3% water, 43% ethanol, and 18.7% solids was coated as a first laydown on top of the backer layer. The backer layer (obtained from Daicel Value Coating Co., Ltd., Japan) contained a protective layer of PET and cyclic olefin copolymer (COC) and was oriented with the COC side up. The coating was done using a drawdown bar with a theoretical wet coating thickness of about 231 μm. While the coating was still wet, a first reinforcing layer of ePTFE membrane 2 restrained on a metal frame was laminated to the IEM laydown, causing the IEM solution to be absorbed into the pores of the first ePTFE membrane. This first intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. Upon drying, the microporous polymer structure of the first ePTFE membrane was completely absorbed with the IEM. A second laydown of the same IEM solution was coated onto the top surface of the first intermediate composite (opposite surface to the backer layer) using a drawdown bar with a theoretical wet coating thickness of about 231 μm. While the coating was still wet, a second reinforcing layer of ePTFE membrane 2, previously restrained on a metal frame, was laminated to the second IEM laydown, causing the IEM solution to be absorbed into the pores of the second ePTFE membrane. This second intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. A third laydown of IEM solution composition of 46% water, 41.6% ethanol, 12.4% solids, 0.085 mg / cm 2The same IEM solution mixed with the recombination catalyst, which is Pt on carbon, was coated on top of the second intermediate composite using a drawdown bar with a theoretical wet coating thickness of about 132 μm. This final composite was subsequently dried in a convection oven at 165 °C with air inside. The multilayer composite membrane was fully occluded and had a layer of IEM on each outer surface and between the two fully occluded reinforcement layers with a separation distance of about 10-12 μm. Additionally, one layer of the outer IEM layer was a recombination catalyst layer formed as the outermost layer. The thickness of the resulting electrolyzer composite membrane at 50% RH was 80-90 μm.

[0167] Comparative Example 1 Comparative Example 1 was prepared according to the following procedure: Weight per area: about 29 g / m 2 A type 2 ePTFE membrane with a thickness of 29 μm, apparent density of 0.22 g / cc and bubble point of 43.5 psi was used as the reinforcing layer. EW=710 g / mol equivalent of SO3 -A PSFA solution as IEM (obtained from EI du Pont de Nemours and Company) with an IEM solution composition of 38.3% water, 43% ethanol, and 18.7% solids was coated as a first laydown on top of the backer layer. The backer layer (obtained from Daicel Value Coating Co., Ltd., Japan) contained a protective layer of PET and cyclic olefin copolymer (COC) and was oriented with the COC side up. The coating was done using a drawdown bar. While the coating was still wet, a first reinforcing layer of ePTFE membrane 2 restrained on a metal frame was laminated to the IEM laydown, causing the IEM solution to be absorbed into the pores of the first ePTFE membrane. This first intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. Upon drying, the microporous polymer structure of the first ePTFE membrane was completely absorbed with the IEM. A second laydown of the same solution of IEM was coated onto the top surface of the first intermediate composite (opposite the backer layer) using a drawdown bar. This final composite was then dried in a convection oven at 165°C with air inside. The multi-layer composite membrane was completely occluded and had a 25 and 35 μm thick layer of IEM on each outer surface. The resulting electrolyzer composite membrane had a thickness of 80.2 μm at 50% RH.

[0168] Comparative Example 2 Comparative Example 2 was prepared according to the following procedure: Weight per area: about 29 g / m 2 A type 2 ePTFE membrane with a thickness of 29 μm, apparent density of 0.22 g / cc and bubble point of 43.5 psi was used as the reinforcing layer. EW=710 g / mol equivalent of SO3 -A PSFA solution as IEM (obtained from EI du Pont de Nemours and Company) with an IEM solution composition of 38.3% water, 43% ethanol, and 18.7% solids was coated as a first laydown on top of the backer layer. The backer layer (obtained from Daicel Value Coating Co., Ltd., Japan) contained a protective layer of PET and cyclic olefin copolymer (COC) and was oriented with the COC side up. The coating was done using a drawdown bar. While the coating was still wet, a first reinforcing layer of ePTFE membrane 2 restrained on a metal frame was laminated to the IEM laydown, causing the IEM solution to be absorbed into the pores of the first ePTFE membrane. This first intermediate composite was then dried at a temperature of 125° C. in a convection oven with air inside. Upon drying, the microporous polymer structure of the first ePTFE membrane was completely absorbed with the IEM. A second laydown of the same solution of IEM was coated onto the top surface of the first intermediate composite (opposite the backer layer) using a drawdown bar. This final composite was then dried in a convection oven at 165°C with air inside. The multi-layer composite membrane was completely occluded and had a 5.45 μm thick layer of IEM on each outer surface. The resulting electrolyzer composite membrane had a thickness of 40.4 μm at 50% RH.

[0169] The properties of the composite membranes of the examples are shown in Table 1 (Figure 15). The properties of the microporous polymer structure used in the composite membranes are shown in Table 2 (Figure 16). The average puncture force of the samples is shown in Figure 13, which shows a graph comparing the average break force of comparable composite membranes (compare Example 1 with Comparative Example 1 and Example 2 with Comparative Example 2, respectively) to the puncture force of the composite membranes, plotted against the thickness (μm) at 50% RH of each electrolyzer composite membrane. The graph also shows the puncture force of commercially available Nafion™ membranes N115, N212 and N211.

[0170] Discussion of results As seen in Figure 13, the commercially available Nafion N115 membrane has a comparable puncture force despite being significantly thicker than Example 1 (122 μm vs. 80-90 μm) and Example 2 (122 μm vs. 40 μm). The improvement in puncture force due to reinforcement is evident when comparing Nafion N212 with Example 2 and Comparative Example 2 (50 μm vs. 40 μm).

[0171] Surprisingly, these data show that for a given membrane thickness (and similar total content of microporous polymer structures in the electrolyzer composite membrane), distributing the microporous polymer structures in at least two reinforcing layers significantly improves the average burst pressure compared to distributing the same PEM thickness and total content of microporous polymer structures in a single reinforcing layer. Thus, the composite membrane according to the present disclosure is highly desirable as it has excellent resistance to puncture by electrolyzer elements during electrolyzer manufacturing without compromising the membrane performance.

[0172] As shown in Table 1 and FIG. 14, in the present invention examples, the addition of a recombination catalyst to the membrane at the outermost surface of the membrane adjacent to or in contact with the anode significantly reduces hydrogen crossover to the anode compared to the commercial Nafion™ N115. Furthermore, it is worth noting that the hydrogen crossover of the commercial membrane exceeded the safety limit of 2% H2 in O2 at about 8 bar, and the experiment had to be stopped at 22 bar because the hydrogen crossover exceeded the explosive limit of 4% H2 in O2. In contrast, all three of the present invention examples had hydrogen crossover well below the safety limit of 2% H2 in O2, even at high pressures of 24-30 bar. Notably, Example 1 was the most stable, with just the minimal increase in hydrogen crossover with increasing pressure. It is worth noting that Example 2, which is about half the thickness of Example 1, also had very low hydrogen crossover and was able to withstand high pressures up to 30 bar. Example 3 has a similar thickness and total content of reinforcing material as Example 1, but with two reinforcing layers instead of three, and with a higher loading of recombination catalyst, the hydrogen crossover is also much lower and it can withstand pressures up to 24 bar. Thus, increasing the number of reinforcing layers beyond two gives the membrane additional mechanical resistance. The addition of recombination catalyst helps ensure that the hydrogen crossover remains below the explosive limit of 4% H2 in O2.

[0173] Although the present invention has been described in detail, modifications within the spirit and scope of the present invention will be readily apparent to those skilled in the art. It will be understood that the aspects of the present invention, parts of the various embodiments, and various features described above and / or in the appended claims can be combined or interchanged in whole or in part. In the foregoing description of the various embodiments, those embodiments that refer to other embodiments can be appropriately combined with other embodiments, as will be understood by those skilled in the art. Furthermore, those skilled in the art will appreciate that the above description is merely illustrative and does not limit the present invention.

Claims

1. a) A reinforcement structure comprising at least two reinforcement layers, each of said at least two reinforcement layers comprising a microporous polymer structure; b) An ion exchange material (IEM) that is at least partially absorbed within the microporous polymer structure of each of said at least two reinforcement layers and that renders the microporous polymer structure occlusive; c) A recombination catalyst configured to be disposed closer to the anode than to the cathode of an electrolyzer composite membrane electrode assembly (MEA); An electrolyzer composite membrane comprising the foregoing, said electrolyzer composite membrane having a thickness of at least 20 μm at 50% RH.

2. The recombination catalyst is present in a recombination catalyst layer configured to be disposed adjacent to the anode of the electrolyzer composite membrane electrode assembly (MEA), or The reinforcement structure defines a cathode outermost surface configured to be disposed closer to the cathode than to the anode in the electrolyzer composite membrane electrode assembly and an anode outermost surface configured to be disposed closer to the anode than to the cathode in the electrolyzer composite membrane electrode assembly, Each of said at least two reinforcement layers defines a first surface and a second surface opposite said first surface, and the first surface of the reinforcement layer configured to be disposed at or near the cathode is the cathode outermost surface and the second surface of the reinforcement layer configured to be disposed at or near the anode is the anode outermost surface, the electrolyzer composite membrane according to Claim 1.

3. The recombination catalyst comprises a single recombination catalyst species or a mixture of recombination catalyst species, or The recombination catalyst is mixed with an ion exchange material and / or the recombination catalyst is present on a recombination catalyst support material, or The electrolyzer composite membrane has a thickness of 250 μm or less at 50% RH, or The total volume of the microporous polymer structure in the electrolyzer composite membrane is at least 10% by volume based on the total volume of the electrolyzer composite membrane, the electrolyzer composite membrane according to claim 1 or claim 2.

4. The electrolyzer composite membrane defines a first composite membrane surface and a second composite membrane surface opposite the first composite membrane surface, The ion exchange material is present in at least one layer on the first composite membrane surface and / or the second composite membrane surface, the electrolyzer composite membrane according to claim 1 or claim 2.

5. The electrolyzer composite membrane includes a first layer of ion exchange material on the first composite membrane surface, and / or, The electrolyzer composite membrane includes a second layer of ion exchange material on the second composite membrane surface, at least one of which is the electrolyzer composite membrane according to claim 4.

6. The first layer of the ion exchange material includes a recombination catalyst, and the first layer of the ion exchange material is configured to be disposed adjacent to the anode of the electrolyzer membrane electrode assembly (MEA), the electrolyzer composite membrane according to claim 5.

7. The electrolyzer composite membrane includes a recombination catalyst layer configured to contact the anode, the electrolyzer composite membrane according to claim 1 or claim 2.

8. The recombination catalyst layer includes one or more recombination catalyst species and at least one of an ion exchange material or a carrier, the electrolyzer composite membrane according to claim 7.

9. The composition of at least two reinforcing layers of the reinforcing structure is the same, or, The composition of at least two reinforcing layers of the reinforcing structure is different, or, The electrolyzer composite membrane includes three reinforcing layers, the electrolyzer composite membrane according to claim 1 or claim 2.

10. The microporous polymer structure includes at least one fluorinated polymer, or, The micro-porous polymer structure contains a hydrocarbon polymer, or, The micro-porous polymer structure contains a hydrocarbon polymer including polyethylene, polypropylene, polycarbonate, polystyrene, polysulfone, PES, PEN, or a mixture thereof, the electrolytic device composite membrane according to claim 1 or claim 2.

11. The at least two reinforcing layers are in direct contact, or, The ion exchange material includes layers of ion exchange material exceeding one layer, The first layer of the ion exchange material is formed from an ion exchange material different from the ion exchange material of the second layer of the ion exchange material, or, The micro-porous polymer structure is such that the ion exchange material is completely absorbed, or, The micro-porous polymer structure of each reinforcing layer has a first surface and a second surface, and The ion exchange material forms a layer on at least one of the first surface or the second surface of each reinforcing layer, or, The micro-porous polymer structure of each reinforcing layer has a first surface and a second surface, and The ion exchange material forms a layer on both the first surface and the second surface of each reinforcing layer, or, The average equivalent volume of the ion exchange material is 240 cc / mol equivalent to 870 cc / mol equivalent, or, The average equivalent volume of the ion exchange material is 350 cc / mol equivalent to 475 cc / mol equivalent, or, Further includes a hydrogen peroxide decomposition catalyst, or, The electrolytic device composite membrane further includes the hydrogen peroxide decomposition catalyst including Ce, Mn, or their oxides, the electrolytic device composite membrane according to claim 1 or claim 2.

12. Further includes at least one support layer removably attached to one or more outer surfaces of the electrolytic device composite membrane, or, The recombination catalyst is 0.10 mg / cm in the electrolytic device composite membrane ２Present in an amount less than, or the recombination catalyst is present in the electrolytic device composite membrane in an amount in the range of 0.0001 mg / cm ２ to 0.09 mg / cm ２ of the electrolytic device composite membrane according to claim 1 or claim 2.

13. The recombination catalyst is in direct contact with the anode, whereby the recombination catalyst is on the outermost surface of the electrolytic device composite membrane, the electrolytic device composite membrane according to claim 1 or claim 2.

14. The recombination catalyst extends from the outermost surface into the electrolytic device composite membrane, whereby the recombination catalyst is absorbed in at least one of the reinforcing layers of the electrolytic device composite membrane, the electrolytic device composite membrane according to claim 13.

15. The recombination catalyst extends from the outermost surface into the electrolytic device composite membrane in the range of 1% to 50% of the thickness of the electrolytic device composite membrane, the electrolytic device composite membrane according to claim 14.

16. at least one electrode, and the electrolytic device composite membrane in contact with the at least one electrode, an electrolytic device composite membrane electrode assembly comprising.

17. the electrolytic device composite membrane is attached to the at least one electrode, or the electrode includes a porous layer, or the electrode includes carbon fibers, or the electrode includes carbon fibers having a diameter of 5 to 30 μm, the electrolytic device composite membrane electrode assembly according to claim 16.

18. further includes a fluid diffusion layer selected from felt, paper or textile materials, carbon / carbon-based diffusion layers, titanium porous sintered powder meshes / plates / fibers / felts, stainless steel meshes or mixtures thereof, or the electrode is Pt / Co / Pd / doped graphene / MoSx (cathode), RuO ２ / IrO ２Selected from Ir&Ru bimetallic oxides, Ir / Pt bimetallic oxides, and Ti, Sn, Ta, Nb, Sb, Pb, Mn oxides mixed with Ir or Ru oxides, or The electrode is selected from Pt / Co / Pd / doped graphene / MoSx (cathode), RuO₂ / IrO₂ / Ir&Ru bimetallic oxides, Ir / Pt bimetallic oxides, and Ti, Sn, Ta, Nb, Sb, Pb, Mn oxides mixed with Ir or Ru oxides, and includes a catalyst support selected from carbon or carbon nanoparticles doped with N, P, S, or B, or The electrode includes doped carbon fibers, or Includes a first electrode and a second electrode, or Includes a first electrode and a second electrode, the first electrode forms an anode, and the second electrode forms a cathode, or Includes a first electrode and a second electrode, the first electrode forms an anode, the second electrode forms a cathode, and the anode is in contact with the recombination catalyst. The electrolytic device composite membrane electrode assembly according to claim 16 or claim 17.

19. A first electrode layer and a second electrode layer, The electrolytic device composite membrane according to claim 1, wherein each of the first electrode layer and the second electrode layer is disposed on the opposite surface of the electrolytic device composite membrane. An electrolytic device composite membrane, A gas diffusion layer disposed between the electrolytic device composite membrane and each of the first electrode layer and the second electrode layer, The electrolytic device composite membrane electrode assembly according to claim 16 or claim 17, comprising

20. The first electrode layer and the second electrode layer are a first electrode catalyst layer and a second electrode catalyst layer, or The first electrode layer and the second electrode layer are a first electrode catalyst layer and a second electrode catalyst layer, and the first electrode catalyst layer and the second electrode catalyst layer are adhered to the electrolytic device composite membrane. The electrolytic device composite membrane electrode assembly according to claim 19.

21. An electrolysis device comprising the electrolysis device composite membrane according to claim 1 or claim 2, or the electrolysis device composite membrane electrode assembly according to claim 16 or claim 17.

22. A method for manufacturing the electrolysis device composite membrane according to claim 1 or claim 2, comprising: a) providing a backing layer and coating the backing layer with a first ionomer by depositing a liquid layer of the first ionomer; b) depositing a first reinforcing layer comprising a microporous polymer structure on the liquid layer of the first ionomer, such that the first ionomer is absorbed or at least partially absorbed into the microporous polymer structure of the first reinforcing layer; c) optionally drying the laminate; d) coating the absorbed first reinforcing layer with a liquid layer of a second ionomer solution; e) depositing a second reinforcing layer comprising a microporous polymer structure on the liquid layer of the second ionomer solution, such that the second ionomer solution is absorbed or at least partially absorbed into the microporous polymer structure of the second reinforcing layer; f) optionally drying the laminate; g) optionally coating the outermost surface of the laminate furthest from the backing layer with a third liquid layer of an ionomer, such that the ionomer is at least partially absorbed into the microporous polymer structure; h) optionally drying the laminate; i) depositing a recombination catalyst layer and optionally drying the laminate; j) optionally depositing a fourth liquid layer of an ionomer on the recombination catalyst layer, and k) drying the laminate. A method comprising the steps of.

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