Electrolytic device, electrolytic process and membrane electrode assembly

Abstract

The application provides an electrolysis device, an electrolysis process and a membrane electrode assembly. The electrolysis device comprises a cathode, an anode, an anion exchange membrane and a liquid supply structure, the thickness of the anode is greater than the thickness of the cathode, the anion exchange membrane is arranged between the cathode and the anode, and the liquid supply structure is used for supplying electrolyte to the side of the anode and not to the side of the cathode. In use, the electrolysis device can ensure the moisture infiltration degree of the dry side of the cathode, avoid catalyst damage and shedding, reduce the interface impedance, and improve the use stability and reliability of the electrolysis device.

Description

Technical Field

[0001] This application relates to the field of electrolysis technology, specifically to electrolysis apparatus, electrolysis process and membrane electrode assembly. Background Technology

[0002] Anion exchange membrane electrolysis (AEMWE) is a novel hydrogen production technology that combines the low cost of alkaline water electrolysis with the high current density of proton exchange membrane water electrolysis. In related technologies, to simplify the system and reduce costs, a single-sided electrolyte inlet method is often adopted. This leads to difficulties in replenishing the liquid on the drying side, and the interface between the anion exchange membrane and the catalyst layer on the drying side is prone to water loss, resulting in a sharp increase in ion conduction impedance, a decrease in catalyst activity, and severely impairing the long-term operational stability and durability of the electrolysis unit. Therefore, further improvements to the electrolysis unit are needed to enhance its performance. Summary of the Invention

[0003] In view of this, this application provides an electrolysis device, an electrolysis process, and a membrane electrode assembly. In this electrolysis device, the thickness of the anode is greater than the thickness of the cathode, allowing water on the anode side to diffuse to the cathode side through an anion exchange membrane. This ensures that the electrolysis device maintains sufficient moisture on the dry side of the cathode during the electrolysis process, preventing catalyst damage and shedding, and guaranteeing the stability and reliability of the electrolysis device.

[0004] In a first aspect, this application provides an electrolysis apparatus, including a cathode, an anode, an anion exchange membrane, and a liquid supply structure, wherein the thickness of the anode is greater than the thickness of the cathode, the anion exchange membrane is disposed between the cathode and the anode, and the liquid supply structure is used to supply electrolyte to the anode side and not to the cathode side.

[0005] Optionally, the thickness difference between the anode and the cathode is 0.05mm-2.45mm.

[0006] Furthermore, the thickness difference between the anode and the cathode is 0.06mm-2.4mm.

[0007] Optionally, the thickness of the anode is 0.1mm-2.5mm.

[0008] Optionally, the thickness of the cathode is 0.05mm-2mm.

[0009] Optionally, the ion exchange capacity of the anion exchange membrane is 1.5 mmol / g to 3 mmol / g.

[0010] Optionally, the thickness of the anion exchange membrane is 20 μm-250 μm.

[0011] Optionally, the material of the anion exchange membrane includes a polymer backbone and functional groups. The polymer backbone includes at least one of polysulfone, polyphenylene ether, polyarylpiperidine, polyarylquinine, polynorbornene, polystyrene, polybenzimidazole, styrene-butadiene block copolymer, and polyethylene. The functional groups include at least one of quaternary ammonium cations, piperidinium cations, imidazolium cations, pyrrolidineium cations, quaternary phosphonium cations, guanidineium cations, quinine ring cations, and triazineium cations.

[0012] Optionally, the cathode includes a cathode gas diffusion layer and a cathode catalyst dispersed in the cathode gas diffusion layer; or, the cathode includes a cathode gas diffusion layer and a cathode catalyst layer stacked on the cathode gas diffusion layer, wherein the cathode catalyst layer is made of cathode catalyst.

[0013] Optionally, the anode includes an anode gas diffusion layer and an anode catalyst dispersed in the anode gas diffusion layer; or, the anode includes an anode gas diffusion layer and an anode catalyst layer stacked on the anode gas diffusion layer, wherein the anode catalyst layer is made of an anode catalyst.

[0014] Optionally, the thickness of the cathode gas diffusion layer is 0.05mm-1.97mm.

[0015] Optionally, the cathode catalyst may be made of at least one metallic element selected from Ru, Au, Ag, Ir, Rh, Pd, Pt, Re, Ni, Mo, W, Mn, Co, Cu, Zn, and Al.

[0016] Optionally, the cathode catalyst layer may further include a first ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylene quinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyether ether ketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyether ether ketone, and sulfonated polysulfone.

[0017] Optionally, the loading of the cathode catalyst in the cathode is 0.1 mg / cm³. 2 -20mg / cm 2 .

[0018] Optionally, the thickness of the anolyte gas diffusion layer is 0.1 mm to 2.46 mm.

[0019] Optionally, the anode catalyst may be made of at least one metallic element selected from Ni, Fe, Co, Mn, Cu, Zn, Al, V, Cr, Mo, Ru, Au, Ag, Ir, Rh, Pd, Pt, and Re.

[0020] Optionally, the anode catalyst layer may further include a second ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylene quinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyether ether ketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyether ether ketone, and sulfonated polysulfone.

[0021] Optionally, the loading of the anode catalyst in the anode is 0.1 mg / cm³. 2 -20mg / cm 2 .

[0022] Secondly, this application provides an electrolysis process, including: An electrolysis apparatus as described in the first aspect is provided, wherein an electrolyte is supplied to the anode side through a liquid supply structure in the electrolysis apparatus while the electrolyte is not supplied to the cathode side, and a voltage is applied to the cathode and the anode to perform electrolysis.

[0023] Optionally, the electrolyte is an aqueous solution containing an electrolyte, wherein the electrolyte includes at least one selected from KOH, NaOH, LiOH, K2CO3, KHCO3, Na2CO3, and NaHCO3, and the concentration of the electrolyte in the electrolyte is 0-7 mol / L.

[0024] Optionally, the electrolysis temperature is 25℃-85℃.

[0025] Thirdly, this application provides an electrolysis device, including a cathode, an anode, and an anion exchange membrane, wherein the thickness of the anode is greater than the thickness of the cathode, the anion exchange membrane is disposed between the cathode and the anode, and during electrolysis, electrolyte is introduced into the anode side while the electrolyte is not introduced into the cathode side.

[0026] Fourthly, this application provides a membrane electrode assembly, including a cathode, an anode, and an anion exchange membrane, wherein the thickness of the anode is greater than the thickness of the cathode, and the anion exchange membrane is disposed between the cathode and the anode.

[0027] In the electrolysis device of this application, the membrane electrode assembly adopts an anode and cathode of unequal thickness, with the anode thickness being greater than the cathode thickness. This ensures the degree of water wetting on the anion exchange membrane and the dry side of the cathode during electrolysis, guaranteeing the structural stability and reliability of the electrolysis device. This is beneficial for obtaining an electrolysis device with high current density and excellent durability. At the same time, the single-sided liquid inlet method simplifies the electrolysis device, reduces its preparation cost and electrolysis cost, and facilitates the use of the electrolysis device in electrolysis processes. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] Figure 1 This is a schematic diagram of an electrolysis apparatus provided in one embodiment of this application.

[0030] Figure 2 A schematic diagram of an electrolysis apparatus provided for another embodiment of this application.

[0031] Figure 3 A schematic diagram of an electrolysis apparatus provided for yet another embodiment of this application.

[0032] Figure 4 This is a cross-sectional schematic diagram of an electrolysis apparatus provided in one embodiment of this application.

[0033] Figure 5 This is a schematic diagram of the operation of an electrolysis apparatus provided in one embodiment of this application.

[0034] Label Explanation: Electrolysis device-100, anode-10, cathode-20, anion exchange membrane-30, membrane electrode assembly-40, liquid supply structure-50, anode chamber-60, cathode chamber-70, anode plate-80, cathode plate-90. Detailed Implementation

[0035] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0036] In related technologies, anion exchange membrane water electrolysis devices can employ dual-sided electrolyte supply during electrolysis, simultaneously supplying electrolyte to both the anode and cathode sides. This effectively maintains the wettability of the anode and the catalyst within it, ensuring interface stability and catalytic activity. However, this supply method requires two independent liquid circulation and gas-liquid separation systems in practical applications, leading to complex equipment structure and significantly increased costs. Therefore, to simplify the system and reduce costs, single-sided electrolyte supply can be used for electrolysis. However, in practical applications, single-sided supply makes replenishing the liquid on the drying side difficult, and the interface between the anion exchange membrane and the drying-side electrode is prone to water loss, resulting in a sharp increase in ion conduction impedance, decreased catalyst activity, and severely compromised long-term operational stability and durability of the electrolysis device.

[0037] In view of this, this application provides an electrolysis apparatus, an electrolysis process, and a membrane electrode assembly.

[0038] This application provides a membrane electrode assembly, including a cathode, an anode, and an anion exchange membrane, wherein the thickness of the anode is greater than the thickness of the cathode, and the anion exchange membrane is disposed between the cathode and the anode.

[0039] This application provides an electrolysis device, including a cathode, an anode, an anion exchange membrane, and a liquid supply structure. The thickness of the anode is greater than the thickness of the cathode. The anion exchange membrane is disposed between the cathode and the anode. The liquid supply structure is used to supply electrolyte to the anode side and not to the cathode side.

[0040] This application provides an electrolysis device, including a cathode, an anode, and an anion exchange membrane. The thickness of the anode is greater than the thickness of the cathode. The anion exchange membrane is disposed between the cathode and the anode. During electrolysis, the electrolyte is introduced into the anode side while the electrolyte is not introduced into the cathode side.

[0041] In this application, the cathode, anode, and anion exchange membrane form a membrane electrode assembly that can be used in an electrolysis device. Simultaneously, the anode is thicker than the cathode, and the thicker anode can be considered as a fluid distribution layer with in-plane permeability, effectively increasing the cross-sectional area of ​​the electrolyte in the direction perpendicular to the flow channel. This forces the liquid to diffuse deeper into the anode, closer to the anion exchange membrane, ensuring uniform reactant concentration and hydration across the entire active area. The cathode side is unfluid, and the thinner cathode reduces the transport path of the electrolyzed hydrogen, minimizing the long-distance water transport by hydrogen in the cathode pores. The membrane electrode assembly can adapt to completely different fluid states on both sides (one side liquid / gas two-phase flow, one side pure gas phase diffusion). Furthermore, the catalytic active sites on the cathode are close to the anion exchange membrane, allowing water molecules to reach the reaction sites without passing through deep electrodes. The interface between the cathode and the anion exchange membrane maintains high water activity, resulting in high water utilization. Therefore, the electrolysis device provided in this application uses an asymmetric electrode configuration where the anode thickness is greater than the cathode thickness. This allows the electrolysis device to form a thick buffer layer on the anode side when liquid is fed in from the anode side only, which can homogenize the gas-liquid two-phase flow and store moisture. On the cathode side, a thin mass transfer layer is formed that only allows hydrogen to diffuse rapidly across the layer. The synergistic effect of the anode and cathode can ensure the distribution of electrolyte and the discharge of generated gas during the electrolysis cycle, as well as the degree of moisture wetting on the dry side of the cathode, avoiding catalyst damage and shedding. It also helps to reduce interfacial impedance and improves the stability and reliability of the electrolysis device.

[0042] Please see Figure 1 This is a schematic diagram of an electrolysis device provided in one embodiment of this application. The electrolysis device 100 includes an anode 10, a cathode 20, and an anion exchange membrane 30. The thickness of the anode 10 is greater than the thickness of the cathode 20, and the anion exchange membrane 30 is disposed between the anode 10 and the cathode 20. The anode 10, cathode 20, and anion exchange membrane 30 constitute a membrane electrode assembly 40. The membrane electrode assembly is the core component of the electrolysis device, and its good interfacial wetting performance is crucial to the performance and stability of the electrolysis device. This application, by setting anodes and cathodes of unequal thickness in a single-sided liquid-inlet electrolysis device, maintains a high water vapor partial pressure at the membrane interface between the cathode and the anion exchange membrane. This prevents the anion exchange membrane from losing water, deforming, and rupturing, ensuring the structural stability of the membrane electrode assembly and its wettability during electrolysis. It also eliminates mass transfer polarization at the cathode electrode interface, resulting in an electrolysis device with high current density and excellent durability. This improves the performance of the electrolysis device. Furthermore, the single-sided liquid-inlet method simplifies the electrolysis device, reduces its manufacturing cost and electrolysis cost, and facilitates its use in electrolysis processes.

[0043] During electrolysis, the electrolyte instinctively seeks the path of least flow resistance from the inlet to the outlet, a phenomenon known as the short-circuit effect. In this application, the anode is fed with electrolyte. Due to its thickness, the anode provides a larger reaction area and more buffer channels, forming a homogenized gas-liquid two-phase system. The anode acts as a thick buffer layer to store water, preventing the electrolyte from directly flowing to the outlet through the short-circuit effect. This increases the penetration and wetting time of the electrolyte within the anode, allowing for uniform distribution of the electrolyte inside and facilitating the movement of water towards the cathode. In some embodiments of this application, the anode thickness is 0.1 mm to 2.5 mm, which is beneficial for water penetration and wetting, thereby aiding in the movement of water towards the cathode. For example, the thickness of the anode may be, but is not limited to, 0.1mm, 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.35mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, or 2.5mm, etc.

[0044] Water diffuses through the anion exchange membrane to the cathode to generate hydrogen gas. Because the cathode in this application is relatively thin, the diffusion path of water is short, allowing hydrogen gas to quickly leave the cathode surface and enter the flow field, reducing concentration polarization. In some embodiments of this application, the cathode thickness is 0.05mm-2mm, which helps to reduce the water diffusion path and ensure the wettability of the cathode. For example, the cathode thickness can be, but is not limited to, 0.05mm, 0.1mm, 0.2mm, 0.25mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.35mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, or 2mm.

[0045] The thickness difference between the anode and cathode makes the hydration state of water in the anode more uniform, which is more conducive to the movement of water to the cathode. Furthermore, the utilization rate of water in the electrolysis device is high, which is beneficial to the electrolysis process. In some embodiments of this application, the thickness difference between the anode and cathode is 0.05mm-2.45mm. This suitable thickness difference facilitates both uniform wetting of the electrolyte on the anode side and the movement of water to the cathode, as well as rapid and uniform wetting of water on the cathode side, ensuring the degree of wetting on the cathode side. Moreover, during electrolysis, the cathode side can react rapidly, and the products can leave quickly, which is beneficial to the stable operation of the electrolysis. For example, the thickness difference between the anode and cathode can be, but is not limited to, 0.05 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.45 mm. In some embodiments, the thickness difference between the anode and cathode can be 0.06 mm to 2.4 mm, which can further improve the performance of the electrolysis device.

[0046] In some embodiments of this application, the ion exchange capacity (IEC) of the anion exchange membrane is 1.5 mmol / g to 3 mmol / g. A high ion exchange capacity of the anion exchange membrane can improve ionic conductivity and ensure OH- - The ability of hydrated water to quickly pass through the membrane results in a higher water absorption rate for the anion exchange membrane. This promotes a lower interfacial contact resistance between the anion exchange membrane and the anode and cathode, facilitating water transport to the interface and ensuring thorough wetting. This allows for better adsorption and retention of moisture, maintaining a moist interface during electrolysis and preventing problems such as dryness and increased interfacial contact resistance. For example, the ion exchange capacity of the anion exchange membrane can be, but is not limited to, 1.5 mmol / g, 1.6 mmol / g, 1.7 mmol / g, 1.8 mmol / g, 1.9 mmol / g, 2 mmol / g, 2.1 mmol / g, 2.2 mmol / g, 2.3 mmol / g, 2.4 mmol / g, 2.5 mmol / g, 2.6 mmol / g, 2.7 mmol / g, 2.8 mmol / g, 2.9 mmol / g, or 3 mmol / g.

[0047] In some embodiments of this application, the thickness of the anion exchange membrane is 20μm-250μm, which is beneficial for reducing ohmic resistance, improving moisture transport, and ensuring its mechanical strength, thus facilitating its use in electrolysis processes. Exemplarily, the thickness of the anion exchange membrane can be, but is not limited to, 20μm, 30μm, 50μm, 75μm, 90μm, 100μm, 110μm, 120μm, 125μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 220μm, or 250μm.

[0048] In some embodiments of this application, the anion exchange membrane is made of a polymer backbone and functional groups. The polymer backbone includes at least one of polysulfone, polyphenylene ether, polyarylpiperidine, polyarylquinine, polynorbornene, polystyrene, polybenzimidazole, styrene-butadiene block copolymer, and polyethylene. The functional groups include at least one of quaternary ammonium cations, piperidinium cations, imidazolium cations, pyrrolidineium cations, quaternary phosphonium cations, guanidinium cations, quinine ring cations, and triazineium cations. These materials are beneficial for improving the ion exchange capacity of the anion exchange membrane, further enhancing its ability to transport water to the cathode.

[0049] In some embodiments of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst dispersed in the cathode gas diffusion layer. This can be achieved, but is not limited to, by placing the cathode gas diffusion layer in a solution containing the cathode catalyst, or by coating (spraying, rolling, etc.) a solution containing the cathode catalyst onto the cathode gas diffusion layer and then drying it to obtain the cathode. In some embodiments, the porosity of the cathode is 20%-80%. The relatively low porosity of the cathode can confine water within the catalytic reaction region inside the cathode, maintaining high water activity at the interface between the cathode and the anion exchange membrane, further improving the reliability of the interface. Exemplarily, the porosity of the cathode can be, but is not limited to, 20%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%. The porosity of this application is measured according to ISO 15901-1:2005 mercury intrusion porosimetry.

[0050] In another embodiment of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst layer stacked on the cathode gas diffusion layer, wherein the cathode catalyst layer is made of cathode catalyst. In this application, the cathode catalyst can be coated onto the cathode gas diffusion layer or the surface of the anion exchange membrane and dried to form the cathode catalyst layer. The coating can be, but is not limited to, application (spraying, roller coating, etc.) or deposition (chemical deposition, vapor deposition, hydrothermal deposition, electrochemical deposition, Joule thermal deposition, etc.). For example, the cathode catalyst layer can be coated onto the surface of the anion exchange membrane before the cathode gas diffusion layer is attached; or the cathode catalyst layer can be coated onto the surface of the cathode gas diffusion layer. In some embodiments, the porosity of the cathode gas diffusion layer is 20%-80%. The relatively low porosity of the cathode gas diffusion layer can confine water inside the cathode, maintaining high water activity at the cathode-anion exchange membrane interface and further improving interface reliability. Exemplarily, the porosity of the cathode gas diffusion layer can be, but is not limited to, 20%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%, etc.

[0051] The gas diffusion layer supports the catalyst layer and also facilitates gas diffusion and transport, ensuring electrolysis. The gas diffusion layer can be a porous structure to facilitate gas transport and diffusion. In some embodiments of this application, the gas diffusion layer includes a gas diffusion substrate. In other embodiments, the gas diffusion layer includes a gas diffusion substrate and a microporous layer disposed on the surface of the gas diffusion substrate. The porosity of the gas diffusion substrate is greater than the porosity of the microporous layer. The gas diffusion substrate and the microporous layer can be made of the same or different materials.

[0052] In some embodiments of this application, the material of the cathode gas diffusion layer can be selected from at least one of carbon materials, elemental nickel, nickel alloys, and stainless steel. For example, carbon materials can be in the form of carbon cloth, carbon paper, carbon felt, etc., while elemental nickel, nickel alloys, and stainless steel can be in the form of fiber felt, powder felt, foam, composite mesh felt, etc.

[0053] In some embodiments of this application, the thickness of the cathode gas diffusion layer is 0.05 mm to 1.97 mm. A suitable thickness of the cathode gas diffusion layer helps to shorten the diffusion path of moisture, allowing the generated hydrogen gas to quickly leave the cathode surface and reducing concentration polarization. Exemplarily, the thickness of the cathode gas diffusion layer can be, but is not limited to, 0.05 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 1.97 mm.

[0054] In some embodiments of this application, the pore size of the cathode gas diffusion layer is 0.1 μm-800 μm, which is beneficial for electrolyte wetting and gas diffusion. Exemplarily, the pore size of the cathode gas diffusion layer can be, but is not limited to, 0.1 μm, 1 μm, 5 μm, 10 μm, 25 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, or 800 μm. Exemplarily, the cathode gas diffusion layer can be a porous metal structure or a porous carbon structure. The pore size in this application is measured according to ISO 15901-1:2005 mercury porosimetry.

[0055] In some embodiments of this application, the cathode catalyst is made of at least one metallic element selected from Ru, Au, Ag, Ir, Rh, Pd, Pt, Re, Ni, Mo, W, Mn, Co, Cu, Zn, and Al. Exemplarily, the cathode catalyst can be selected from elemental forms, alloys, sulfides, phosphides, etc., containing at least one of the above metallic elements. For example, the cathode catalyst can be selected from platinum-supported carbon (Pt / C). In some embodiments, the mass content of platinum in the platinum-supported carbon can be 20%-60%. Exemplarily, the mass content of platinum in the platinum-supported carbon can be, but is not limited to, 20%, 30%, 40%, 50%, or 60%.

[0056] In some embodiments of this application, the thickness of the cathode catalyst layer can be 1 μm-40 μm, which is beneficial for the cathode catalyst to exert its catalytic effect. Exemplarily, the thickness of the cathode catalyst layer can be, but is not limited to, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 33 μm, 35 μm, 37 μm, or 40 μm, etc.

[0057] In some embodiments of this application, the cathode catalyst layer further includes a first ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylene quinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyether ether ketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyether ether ketone, and sulfonated polysulfone. In some embodiments, the mass content of the cathode catalyst in the cathode catalyst layer is 50%-98%, which is beneficial for the electrolysis reaction. For example, the mass content of the cathode catalyst in the cathode catalyst layer may be, but is not limited to, 50%, 55%, 58%, 60%, 65%, 67%, 70%, 72%, 75%, 80%, 83%, 85%, 88%, 90%, 93%, 95%, 96%, or 98%.

[0058] In some embodiments of this application, the loading of the cathode catalyst in the cathode catalyst layer is 0.1 mg / cm³. 2 -20mg / cm 2 A suitable loading of the cathode catalyst can achieve efficient hydrogen evolution. For example, the loading of the cathode catalyst in the cathode catalyst layer can be, but is not limited to, 0.1 mg / cm³. 2 0.5 mg / cm 2 0.8 mg / cm 2 1mg / cm 2 2mg / cm 2 5mg / cm 2 6mg / cm 2 8mg / cm 2 10mg / cm 2 13mg / cm 2 15mg / cm 2 19mg / cm 2 Or 20mg / cm 2 wait.

[0059] In some embodiments of this application, the loading of the cathode catalyst in the cathode is 0.1 mg / cm³. 2 -20mg / cm 2 A suitable loading of the cathode catalyst can achieve efficient hydrogen evolution. For example, the loading of the cathode catalyst in the cathode catalyst layer can be, but is not limited to, 0.1 mg / cm³. 2 0.5 mg / cm 2 0.8 mg / cm 2 1mg / cm 22mg / cm 2 5mg / cm 2 6mg / cm 2 8mg / cm 2 10mg / cm 2 13mg / cm 2 15mg / cm 2 19mg / cm 2 Or 20mg / cm 2 wait.

[0060] In some embodiments of this application, the surface roughness Ra of the cathode surface near the anion exchange membrane is 1 μm-30 μm. Suitable surface roughness of the cathode can prevent anion exchange membrane puncture caused by assembly pressure or during electrolysis, improving the structural integrity of the membrane electrode assembly and electrolysis device. Exemplarily, the surface roughness Ra of the cathode surface near the anion exchange membrane can be, but is not limited to, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 27 μm, or 30 μm. This application measures the surface roughness Ra according to ISO 4287:1997.

[0061] In some embodiments of this application, the anode includes an anode gas diffusion layer and an anode catalyst dispersed in the anode gas diffusion layer. This can be achieved, but is not limited to, by placing the anode gas diffusion layer in a solution containing the anode catalyst, or by coating (spraying, rolling, etc.) a solution containing the anode catalyst onto the anode gas diffusion layer and then drying it to obtain the anode. In some embodiments, the porosity of the anode is 40%-95%. A relatively high porosity of the anode allows for sufficient water permeation within the anode, further improving the electrolysis effect. Exemplarily, the porosity of the anode can be, but is not limited to, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%.

[0062] In another embodiment of this application, the anode includes an anode gas diffusion layer and an anode catalyst layer stacked on the anode gas diffusion layer, wherein the anode catalyst layer is made of an anode catalyst. In this application, the anode catalyst can be coated onto the surface of the anode gas diffusion layer or an anion exchange membrane and dried to form the anode catalyst layer. Coating can be, but is not limited to, application (spraying, roller coating, etc.) or deposition (chemical deposition, vapor deposition, hydrothermal deposition, electrochemical deposition, Joule thermal deposition, etc.). For example, the anode catalyst layer can be coated onto the surface of the anion exchange membrane before the anode gas diffusion layer is attached; or the anode catalyst layer can be coated onto the surface of the anode gas diffusion layer. In some embodiments, the porosity of the anode gas diffusion layer is 40%-95%. The relatively high porosity of the anode gas diffusion layer allows water to fully permeate inside the anode, further improving the electrolysis effect. Exemplarily, the porosity of the anode gas diffusion layer can be, but is not limited to, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%.

[0063] In some embodiments of this application, the material of the anode gas diffusion layer can be selected from at least one of elemental nickel, nickel alloys, and stainless steel. For example, elemental nickel, nickel alloys, and stainless steel can be in the form of fiber felt, powder felt, foam, composite mesh felt, etc.

[0064] In some embodiments of this application, the thickness of the anode gas diffusion layer is 0.1 mm to 2.46 mm. A suitable thickness of the anode gas diffusion layer can increase the thickness of the anode, which is beneficial for providing more buffer channels and improving the uniform distribution of the electrolyte inside the anode. Exemplarily, the thickness of the anode gas diffusion layer can be, but is not limited to, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, or 2.46 mm, etc.

[0065] In some embodiments of this application, the pore size of the anode gas diffusion layer is 0.1 μm-800 μm, which is beneficial for electrolyte wetting and gas diffusion. Exemplarily, the pore size of the anode gas diffusion layer can be, but is not limited to, 0.1 μm, 1 μm, 5 μm, 10 μm, 25 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, or 800 μm. Exemplarily, the anode gas diffusion layer can be a porous metal structure.

[0066] In some embodiments of this application, the thickness of the anode gas diffusion layer is greater than the thickness of the cathode gas diffusion layer, further increasing the thickness difference between the anode and the cathode, so that the anode and cathode work together to improve the performance of the membrane electrode assembly and the electrolysis device.

[0067] In some embodiments of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst dispersed in the cathode gas diffusion layer, and the anode includes an anode gas diffusion layer and an anode catalyst dispersed in the anode gas diffusion layer, wherein the porosity of the anode is greater than that of the cathode. In other embodiments of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst dispersed in the cathode gas diffusion layer, and the anode includes an anode gas diffusion layer and an anode catalyst layer stacked on the anode gas diffusion layer, wherein the porosity of the anode gas diffusion layer is greater than that of the cathode. In still other embodiments of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst layer stacked on the cathode gas diffusion layer, and the anode includes an anode gas diffusion layer and an anode catalyst dispersed in the anode gas diffusion layer, wherein the porosity of the anode is greater than that of the cathode gas diffusion layer. In still other embodiments of this application, the cathode includes a cathode gas diffusion layer and a cathode catalyst layer stacked on the cathode gas diffusion layer, and the anode includes an anode gas diffusion layer and an anode catalyst layer stacked on the anode gas diffusion layer, wherein the porosity of the anode gas diffusion layer is greater than that of the cathode gas diffusion layer. By setting the porosity of the anode or anode gas diffusion layer to be greater than that of the cathode or cathode gas diffusion layer, the electrolysis process can be fully completed and the cathode side wettability is good, thus improving the reliability of the electrolysis device.

[0068] The anode catalyst can be, but is not limited to, non-noble metal-based catalysts with high oxygen evolution activity. In some embodiments of this application, the anode catalyst is made of at least one metallic element selected from Ni, Fe, Co, Mn, Cu, Zn, Al, V, Cr, Mo, Ru, Au, Ag, Ir, Rh, Pd, Pt, and Re. Exemplarily, the cathode catalyst can be selected from elemental forms, alloys, oxides (such as spinel oxides, perovskite oxides, etc.), and hydroxides (such as layered double hydroxides) containing at least one of the above metallic elements.

[0069] In some embodiments of this application, the thickness of the anode catalyst layer can be 1 μm-40 μm, which is beneficial for the anode catalyst to exert its catalytic effect. For example, the thickness of the anode catalyst layer can be, but is not limited to, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 13 μm, 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 33 μm, 35 μm, 37 μm or 40 μm, etc.

[0070] In some embodiments of this application, the anode catalyst layer further includes a second ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylene quinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyether ether ketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyether ether ketone, and sulfonated polysulfone. In some embodiments, the mass content of the anode catalyst in the anode catalyst layer is 50%-98%, which is beneficial for the electrolysis reaction. For example, the mass content of the anode catalyst in the anode catalyst layer may be, but is not limited to, 50%, 55%, 58%, 60%, 65%, 67%, 70%, 72%, 75%, 80%, 83%, 85%, 88%, 90%, 93%, 95%, 96%, or 98%.

[0071] In some embodiments of this application, the loading of the anolyte catalyst in the anolyte catalyst layer is 0.1 mg / cm³. 2 -20mg / cm 2 An appropriate loading of the anolyte catalyst can reduce overpotential and improve the adhesion stability of the catalyst. For example, the loading of the anolyte catalyst in the anolyte catalyst layer can be, but is not limited to, 0.1 mg / cm³. 2 0.5 mg / cm 2 0.8 mg / cm 2 1mg / cm 2 2mg / cm 2 5mg / cm 2 6mg / cm 2 8mg / cm 2 10mg / cm 2 13mg / cm 2 15mg / cm 2 19mg / cm 2 Or 20mg / cm 2 wait.

[0072] In some embodiments of this application, the loading of the anolyte catalyst in the anode is 0.1 mg / cm³. 2 -20mg / cm 2 An appropriate loading of the anode catalyst can reduce overpotential and improve the adhesion stability of the catalyst. For example, the loading of the anode catalyst in the anode can be, but is not limited to, 0.1 mg / cm³. 2 0.5 mg / cm 2 0.8 mg / cm 21mg / cm 2 2mg / cm 2 5mg / cm 2 6mg / cm 2 8mg / cm 2 10mg / cm 2 13mg / cm 2 15mg / cm 2 19mg / cm 2 Or 20mg / cm 2 wait.

[0073] In some embodiments of this application, the surface roughness Ra of the anode surface near the anion exchange membrane is 1 μm-30 μm. Suitable surface roughness of the anode can prevent anion exchange membrane puncture caused by assembly pressure or during electrolysis, thus improving the structural integrity of the membrane electrode assembly and the electrolysis device. Exemplarily, the surface roughness Ra of the anode surface near the anion exchange membrane can be, but is not limited to, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 22 μm, 25 μm, 27 μm, or 30 μm.

[0074] In this application, the catalysts in the anode and cathode can be in the form of particles, flakes, petals, rods, fibers, etc. The catalysts can be porous or non-porous structures, and the catalysts can be connected to the gas diffusion layer and anion exchange membrane by physical bonding and / or chemical bonds.

[0075] Please see Figure 2 The diagram below illustrates an electrolysis apparatus according to another embodiment of this application. The electrolysis apparatus 100 includes an anode 10, a cathode 20, an anion exchange membrane 30, and a liquid supply structure 50. The thickness of the anode 10 is greater than the thickness of the cathode 20. The anion exchange membrane 30 is disposed between the anode 10 and the cathode 20. The liquid supply structure 50 supplies electrolyte to the anode 10 side but not to the cathode 20 side. The liquid supply structure is used to supply electrolyte to the anode side, ensuring the electrolysis apparatus can be used in the electrolysis process.

[0076] In some embodiments of this application, the electrolysis apparatus includes a cathode, an anode, an anion exchange membrane, an anode chamber, and a cathode chamber. The thickness of the anode is greater than the thickness of the cathode. The side of the anode away from the anion exchange membrane is the anode chamber, and the side of the cathode away from the anion exchange membrane is the cathode chamber. The anion exchange membrane is disposed between the cathode and the anode. During electrolysis, electrolyte is introduced into the anode side while the electrolyte is not introduced into the cathode side. In some embodiments, the anode chamber has an anode inlet for conveying electrolyte. In some embodiments, the anode chamber has an anode outlet for discharging electrolyte and oxygen. In some embodiments, the cathode chamber has a cathode outlet for discharging hydrogen gas.

[0077] Please see Figure 3 This is a schematic diagram of an electrolysis apparatus according to another embodiment of this application. The electrolysis apparatus 100 includes an anode 10, a cathode 20, an anion exchange membrane 30, a liquid supply structure 50, an anode chamber 60, and a cathode chamber 70. The thickness of the anode 10 is greater than the thickness of the cathode 20. The side of the anode 10 away from the anion exchange membrane 30 is the anode chamber 60, and the side of the cathode 20 away from the anion exchange membrane 30 is the cathode chamber 70. The anion exchange membrane 30 is disposed between the anode 10 and the cathode 20. The liquid supply structure 50 is used to supply electrolyte to the anode 10 side but not to the cathode 20 side. That is, the liquid supply structure is used to supply electrolyte to the anode chamber but not to the cathode chamber.

[0078] In some embodiments of this application, the electrolysis apparatus further includes an anode plate, with the anode disposed between the anode plate and the anion exchange membrane, forming an anode chamber between the anode and the anode plate. In some embodiments, the surface of the anode plate near the anode has grooves, so that the space formed by these grooves can serve as an anode chamber. In another embodiment, an anode perforated layer is disposed between the anode plate and the anode, and the space formed by these perforated layers can serve as an anode chamber. The perforated layer can be, but is not limited to, a gasket or an electrode frame, etc.

[0079] In some embodiments of this application, the anode chamber has an anode flow channel for the introduction and discharge of electrolyte and gas. Exemplarily, the anode flow channel can be a lattice flow channel structure, a serpentine flow channel structure, a parallel flow channel structure, an interdigitated flow channel structure, a serpentine-parallel composite flow channel structure, a meandering flow channel structure, a planar grid flow channel structure, a braided topology flow channel structure, a deformable grid flow channel structure, etc. In some embodiments, the cross-section of the anode flow channel can be at least rectangular and trapezoidal. In some embodiments, the width or aperture of the anode flow channel is 0.2mm-3mm. Exemplarily, the width or aperture of the anode flow channel can be, but is not limited to, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. In some embodiments, the depth of the anode flow channel is 0.2mm-3mm. Exemplarily, the depth of the anode flow channel can be, but is not limited to, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. In some embodiments, the ridge width of the anode channel is 0.2 mm to 3 mm. The ridge width is the width between adjacent channels. Exemplarily, the ridge width of the anode channel may be, but is not limited to, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm. The above-mentioned anode channel dimensions facilitate the introduction and discharge of electrolyte and gas.

[0080] In some embodiments of this application, the electrolysis apparatus further includes a cathode plate disposed between the cathode plate and the anion exchange membrane, forming a cathode chamber between the cathode and the cathode plate. In some embodiments, the surface of the cathode plate near the cathode has grooves, so that the space formed by these grooves can serve as a cathode chamber. In another embodiment, a cathode perforated layer is disposed between the cathode plate and the cathode, and the space formed by these perforated layers can serve as a cathode chamber. The perforated layer may be, but is not limited to, a gasket or an electrode frame.

[0081] In some embodiments of this application, the cathode chamber has a cathode flow channel for gas discharge. Exemplarily, the cathode flow channel may be a lattice flow channel structure, a serpentine flow channel structure, a parallel flow channel structure, an interdigitated flow channel structure, a serpentine-parallel composite flow channel structure, a meandering flow channel structure, a planar grid flow channel structure, a woven topology flow channel structure, or a deformable grid flow channel structure. In some embodiments, the width or aperture of the cathode flow channel is 0.2mm-3mm. Exemplarily, the width or aperture of the cathode flow channel may be, but is not limited to, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. In some embodiments, the depth of the cathode flow channel is 0.2mm-3mm. Exemplarily, the depth of the cathode flow channel may be, but is not limited to, 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. In some embodiments, the ridge width of the cathode flow channel is 0.2mm-3mm. For example, the ridge width of the cathode flow channel can be, but is not limited to, 0.2 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm. The above-mentioned cathode flow channel dimensions are beneficial for gas discharge.

[0082] In some embodiments of this application, the liquid supply structure includes a gas-liquid separator, an inlet, and an outlet. The gas-liquid separator is used to contain electrolyte, the inlet is used to replenish electrolyte in the gas-liquid separator, and the outlet is used to deliver electrolyte to the anode side. In some embodiments, the anode chamber has an anode inlet, and the outlet of the liquid supply structure is connected to the anode inlet for supplying electrolyte to the anode side. Exemplarily, the electrolysis apparatus may also include a connection structure for connecting the outlet of the liquid supply structure and the anode inlet. In some embodiments, the anode outlet of the anode chamber is connected to the inlet of the liquid supply structure, thus forming an anode circulation loop. The inlet is also used to receive oxygen and electrolyte delivered by the anode.

[0083] Please see Figure 4 This is a cross-sectional schematic diagram of an electrolysis apparatus provided in one embodiment of this application. The electrolysis apparatus 100 includes an anode 10, a cathode 20, an anion exchange membrane 30, an anode chamber 60, a cathode chamber 70, an anode plate 80, and a cathode plate 90. The thickness of the anode 10 is greater than the thickness of the cathode 20. The anion exchange membrane 30 is disposed between the anode 10 and the cathode 20. The anode 10 is disposed between the anode plate 80 and the anion exchange membrane 30, forming the anode chamber 60 between the anode 10 and the anode plate 80. The cathode 20 is disposed between the cathode plate 90 and the anion exchange membrane 30, forming the cathode chamber 70 between the cathode 20 and the cathode plate 90. Exemplarily, the electrolysis apparatus may also have a liquid supply structure.

[0084] In some embodiments of this application, the anode plate, membrane electrode assembly, and cathode plate are stacked sequentially to form a repeating unit, and the electrolysis apparatus may include at least one of the aforementioned repeating units. For example, the anode plate, membrane electrode assembly, and cathode plate may be stacked in series to form a repeating unit.

[0085] The electrolysis apparatus provided in this application can be used to produce hydrogen, oxygen, etc. For example, the electrolysis apparatus can generate gas at a pressure of 0.1 MPa or higher. The electrolysis apparatus can be, but is not limited to, an anion exchange membrane (AEM) electrolyzer.

[0086] This application provides an electrolysis process, comprising: providing an electrolysis apparatus as described in any of the above embodiments, introducing an electrolyte to the anode side while not introducing an electrolyte to the cathode side, and applying a voltage to the cathode and anode to perform electrolysis. In this application, an electrolyte can be introduced to the anode side through a liquid supply structure in the electrolysis apparatus while not introducing an electrolyte to the cathode side. The voltage can be provided by renewable energy or mains power, and the electrolysis can operate in a steady state or with dynamic fluctuations. In the electrolysis apparatus provided by this application, the membrane electrode assembly has excellent internal interface performance, and the dry side can be guaranteed to be wetted by moisture during electrolysis, without problems such as drying or cracking, thus improving electrolysis efficiency and reducing electrolysis costs.

[0087] The electrolyte can be selected as needed. In some embodiments of this application, the electrolyte is an aqueous solution containing an electrolyte. Exemplarily, the electrolyte may include, but is not limited to, at least one selected from KOH, NaOH, LiOH, K₂CO₃, KHCO₃, Na₂CO₃, and NaHCO₃. In some embodiments, the concentration of the electrolyte in the electrolyte is less than or equal to 7 mol / L, which is beneficial for water electrolysis. Exemplarily, the concentration of the electrolyte in the electrolyte may be, but is not limited to, 0.1 mol / L, 0.2 mol / L, 0.5 mol / L, 0.7 mol / L, 1 mol / L, 1.3 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, 2.5 mol / L, 2.7 mol / L, 3 mol / L, 3.5 mol / L, 3.8 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L, 5.5 mol / L, 6 mol / L, 6.5 mol / L, or 7 mol / L, etc. For example, the concentration of electrolyte in the electrolyte solution can be 0.1 mol / L to 2 mol / L, which is beneficial for electrolysis.

[0088] During electrolysis, the anode reaction is 4OH⁻. - →O2 + 2H2O + 4e - The cathode reaction process is 4H₂O + 4e⁻ - →2H₂ + 4OH⁻ - Please see. Figure 5This is a schematic diagram of the operation of an electrolysis device provided in one embodiment of this application. Arrow a1 indicates the direction of electrolyte inlet, arrow a2 indicates the direction of water movement, and arrow a3 indicates the direction of OH-. - The direction of movement is indicated by arrow a4, which is the discharge direction of the anode outlet in the anode chamber 60, and arrow a5, which is the discharge direction of the cathode outlet in the cathode chamber 70.

[0089] In some embodiments of this application, the electrolysis temperature can be between 25°C and 85°C, which is beneficial for the electrolysis process. Exemplary examples include, but are not limited to, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, or 85°C. In some embodiments, the electrolysis temperature can be between 30°C and 80°C.

[0090] The effects of the technical solution in this application will be further illustrated below with specific examples.

[0091] Example 1 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then ultrasonically sprayed onto a 0.2 mm thick carbon paper (porosity 60%, average pore size 30 μm), and dried to form a cathode catalyst layer. The Pt / C loading in the cathode catalyst layer was 1.25 mg / cm³. 2 A cathode with a thickness of 0.21 mm was fabricated.

[0092] In-situ growth of NiFe-layered double hydroxide (NiFe-LDH) on a nickel foam surface forms an integrated electrode as the anode; the anode has a thickness of 0.3 mm, a porosity of 80%, and an average pore size of 200 μm.

[0093] An anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) and a cathode are stacked to form a membrane electrode assembly. The surface roughness of the anode side near the anion exchange membrane is 12 μm, and the surface roughness of the cathode side near the anion exchange membrane is 8 μm.

[0094] Example 2 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then coated onto a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) using ultrasonic spraying. After drying, a cathode catalyst layer was formed with a Pt / C loading of 1.25 mg / cm³. 2A 0.2 mm thick layer of carbon paper (with a porosity of 60% and an average pore size of 30 μm) was placed on the cathode catalyst layer, resulting in a cathode thickness of 0.21 mm.

[0095] In-situ growth of nickel foam on the surface of NiFe-LDH forms an integrated electrode as the anode; the anode has a thickness of 1 mm, a porosity of 80%, and an average pore size of 200 μm.

[0096] An anode is placed on the side of the anion exchange membrane away from the cathode to form a membrane electrode assembly.

[0097] Example 3 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then coated onto a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) using ultrasonic spraying. After drying, a cathode catalyst layer was formed with a Pt / C loading of 1.25 mg / cm³. 2 A 0.2 mm thick layer of carbon paper (with a porosity of 60% and an average pore size of 30 μm) was placed on the cathode catalyst layer, resulting in a cathode thickness of 0.21 mm.

[0098] NiFe-LDH and quaternized polyarylpiperidine anion exchange polymer were mixed at a mass ratio of 7:3 to form an anode catalyst slurry. The anode catalyst slurry was then ultrasonically sprayed onto a 0.3 mm thick nickel felt (70% porosity, average pore size 20 μm), and dried to form an anode catalyst layer with a catalyst loading of 5 mg / cm³. 2 Anodes with a thickness of 0.308 mm were fabricated.

[0099] An anode is placed on the side of the anion exchange membrane away from the cathode to form a membrane electrode assembly.

[0100] Example 4 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then ultrasonically sprayed onto a 0.2 mm thick carbon paper (porosity 60%, average pore size 30 μm), and dried to form a cathode catalyst layer. The Pt / C loading in the cathode catalyst layer was 1.25 mg / cm³. 2 A cathode with a thickness of 0.21 mm was fabricated.

[0101] NiFe-LDH and quaternized polyarylpiperidine anion exchange polymer were mixed at a mass ratio of 7:3 to form an anode catalyst slurry. The anode catalyst slurry was then ultrasonically sprayed onto a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm), and dried to form an anode catalyst layer with a catalyst loading of 5 mg / cm³. 2 A 0.308mm thick anode is formed by placing a 0.3mm thick nickel felt (70% porosity, average pore size 20μm) on the anode catalyst layer.

[0102] A cathode is placed on the side of the anion exchange membrane away from the cathode to form a membrane electrode assembly.

[0103] Example 5 Self-supporting platinum-based nickel foam was used as the cathode, with a Pt loading of 0.5 mg / cm³. 2 The cathode has a thickness of 0.2 mm, a porosity of 50%, and an average pore size of 200 μm.

[0104] NiFe-LDH and quaternized polyarylpiperidine anion exchange polymer were mixed at a mass ratio of 7:3 to form an anode catalyst slurry. The anode catalyst slurry was then ultrasonically sprayed onto a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm), and dried to form an anode catalyst layer with a catalyst loading of 5 mg / cm³. 2 A 0.308mm thick anode was formed by placing a 0.3mm thick nickel felt (with a porosity of 60% and an average pore size of 20μm) on the anode catalyst layer.

[0105] An anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) and a cathode are stacked to form a membrane electrode assembly.

[0106] Example 6 Self-supporting platinum-based nickel foam was used as the cathode, with a Pt loading of 0.5 mg / cm³. 2 The cathode has a thickness of 0.5 mm, a porosity of 50%, and an average pore size of 200 μm.

[0107] In-situ growth of NiFe on nickel foam surface to form an integrated electrode as anode; the anode has a thickness of 1 mm, a porosity of 80%, and an average pore size of 200 μm.

[0108] An anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) and a cathode are stacked to form a membrane electrode assembly.

[0109] Example 7 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then ultrasonically sprayed onto 0.2 mm thick carbon paper (porosity 60%, average pore size 30 μm), and dried to form a cathode catalyst layer. The Pt / C loading in the cathode catalyst layer was 1.25 mg / cm³. 2 A cathode with a diameter of 0.21 mm was fabricated.

[0110] In-situ growth of nickel foam on the surface of NiFe-LDH forms an integrated electrode as the anode. The anode has a thickness of 0.3 mm, a porosity of 80%, and an average pore size of 200 μm.

[0111] A membrane electrode assembly is formed by stacking an anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 1.4 mmol / g, thickness 75 μm) and a cathode.

[0112] Example 8 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then coated onto 0.2 mm thick carbon paper (porosity 60%, average pore size 30 μm) using ultrasonic spraying. After drying, a cathode catalyst layer was formed, with a Pt / C loading of 1.25 mg / cm³. 2 A cathode with a diameter of 0.21 mm was fabricated.

[0113] In-situ growth of nickel foam on the surface of NiFe-LDH forms an integrated electrode as the anode. The anode has a thickness of 0.3 mm, a porosity of 80%, and an average pore size of 200 μm.

[0114] A membrane electrode assembly is formed by stacking an anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 3.2 mmol / g, thickness 75 μm) and a cathode.

[0115] Example 9 It is largely the same as Example 1, except that the cathode is 0.1 mm and the anode is 2.5 mm.

[0116] Example 10 It is largely the same as Example 1, except that the cathode is 0.1 mm and the anode is 3 mm.

[0117] Comparative Example 1 It is largely the same as Example 1, except that the anode thickness is 0.21 mm, and the cathode and anode have the same thickness.

[0118] Comparative Example 2 A cathode catalyst slurry was prepared by mixing a Pt / C cathode catalyst (Pt content in Pt / C was 40% by mass) and a quaternized polyarylpiperidine anion exchange polymer at a mass ratio of 7:3. The cathode catalyst slurry was then coated onto a 0.4 mm thick carbon paper (porosity 60%, average pore size 30 μm) using ultrasonic spraying. After drying, a cathode catalyst layer was formed, in which the Pt / C loading was 1.25 mg / cm³. 2 A cathode with a thickness of 0.41 mm was fabricated.

[0119] In-situ growth of nickel foam on the surface of NiFe-LDH forms an integrated electrode as the anode; the anode has a thickness of 0.3 mm, a porosity of 80%, and an average pore size of 200 μm.

[0120] A membrane electrode assembly is formed by stacking an anode, a quaternized polyarylpiperidine anion exchange membrane (IEC 2.5 mmol / g, thickness 75 μm) and a cathode.

[0121] Performance testing An electrolysis device is formed by stacking and assembling the aforementioned membrane electrode assembly with an anode plate and a cathode plate in an electrolytic cell. The anode chamber flow channel between the membrane electrode assembly and the anode plate is a serpentine flow channel with a rectangular cross-section, a width of 0.8 mm, a depth of 0.8 mm, and a ridge width of 0.5 mm. The cathode chamber flow channel between the membrane electrode assembly and the cathode plate is a parallel flow channel with a rectangular cross-section, a width of 1.5 mm, a depth of 0.5 mm, and a ridge width of 0.5 mm. Electrolysis is performed on the above electrolysis device, which may have a liquid supply device that circulates liquid only to the anode side, without liquid entering the cathode side. The electrolyte is a 1M KOH solution, and the operating temperature is 60℃. The ohmic impedance and water electrolysis performance of the electrolysis device are tested.

[0122] Ohmic impedance: Using an electrochemical workstation, the working electrode (WE) line and the working sensing electrode (WS) line were connected to the cathode side plate, and the reference electrode (RE) line and the auxiliary electrode line were connected to the anode side plate. The constant voltage AC impedance of the test object was measured at open circuit potential, with a high frequency of 100,000 Hz, a low frequency of 1 Hz, and an amplitude of 10 mV. After fitting the test results, the ohmic impedance (HFR) value was calculated based on the electrode area (the smaller of the anode surface area and the cathode surface area; in this test, the anode and cathode surface areas were equal). The results are shown in Table 1.

[0123] Electrolysis performance of the water electrolysis unit: Using an electrochemical workstation, the working electrode (WE) line and the working sensing electrode (WS) line are connected to the cathode side plate, and the reference electrode (RE) line and the auxiliary electrode line are connected to the anode side plate. A constant current testing method is employed, at 0 A / cm². 2 -1A / cm 2At a current of 0A / cm, set 10 current steps (0A / cm). 2 0.1A / cm 2 0.2A / cm 2 0.9A / cm 2 1A / cm 2 Each step was tested for 5 minutes, and a voltage value was recorded every second. The voltage after stabilization on each current step was recorded, as well as the response potential difference and stable voltage during the load increase process. The results are shown in Table 1.

[0124] Table 1 Performance Test Results

[0125] As can be seen, compared with Example 1, the cathode and anode thicknesses are equal in Comparative Example 1, but the cathode thickness is greater than the anode thickness, which is not conducive to the distribution of fluid in the cathode and anode. This makes the interface between the cathode and the anion exchange membrane prone to water loss and instability, resulting in poor wetting and poor electrolysis performance. In contrast, the embodiment of this application adopts an unequal thickness setting where the anode thickness is greater than the cathode thickness, ensuring the degree of water wetting on the dry side of the anion exchange membrane and reducing the interfacial impedance. The ohmic impedance of this electrolysis device is lower, the operating voltage at 0.5 A / cm² is lower, the operating voltage at 1 A / cm² is lower, and the response potential difference is lower. The long-term operational stability is fundamentally improved, and the voltage decay rate is reduced. Furthermore, compared with Examples 7 and 8, the unequal thickness design in Example 1, combined with an anion exchange membrane suitable for IEC, facilitates further water transport to the interface between the anion exchange membrane and the cathode, further improving the interfacial contact impedance between the anion exchange membrane and the anode and cathode, resulting in superior overall performance of the electrolysis device. Compared to Example 10, the thickness difference between the anode and cathode in Examples 1 and 9 is more suitable, the cathode side wettability is better, and the cathode catalyst is more stable, resulting in a better decay rate of the electrolysis device.

[0126] The above description is an exemplary embodiment of this application, but it should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. An electrolysis apparatus, characterized in that, It includes a cathode, an anode, an anion exchange membrane, and a liquid supply structure. The thickness of the anode is greater than the thickness of the cathode. The anion exchange membrane is disposed between the cathode and the anode. The liquid supply structure is used to supply electrolyte to the anode side but not to the cathode side.

2. The electrolysis apparatus as described in claim 1, characterized in that, The thickness difference between the anode and the cathode is 0.05 mm to 2.45 mm; and / or, The thickness of the anode is 0.1 mm to 2.5 mm; and / or, The thickness of the cathode is 0.05mm-2mm.

3. The electrolysis apparatus as described in claim 2, characterized in that, The thickness difference between the anode and the cathode is 0.06 mm to 2.4 mm.

4. The electrolysis apparatus as described in claim 1, characterized in that, The anion exchange membrane has an ion exchange capacity of 1.5 mmol / g to 3 mmol / g.

5. The electrolysis apparatus as described in claim 1, characterized in that, The thickness of the anion exchange membrane is 20 μm-250 μm; and / or, The anion exchange membrane is made of a polymer backbone and functional groups. The polymer backbone includes at least one of polysulfone, polyphenylene ether, polyarylpiperidine, polyarylquinine, polynorbornene, polystyrene, polybenzimidazole, styrene-butadiene block copolymer, and polyethylene. The functional groups include at least one of quaternary ammonium cations, piperidinium cations, imidazolium cations, pyrrolidineium cations, quaternary phosphonium cations, guanidinium cations, quinine ring cations, and triazineium cations.

6. The electrolysis apparatus as described in claim 1, characterized in that, The cathode includes a cathode gas diffusion layer and a cathode catalyst dispersed in the cathode gas diffusion layer; or, the cathode includes a cathode gas diffusion layer and a cathode catalyst layer stacked on the cathode gas diffusion layer, wherein the cathode catalyst layer is made of cathode catalyst. The anode includes an anode gas diffusion layer and an anode catalyst dispersed in the anode gas diffusion layer, or the anode includes an anode gas diffusion layer and an anode catalyst layer stacked on the anode gas diffusion layer, wherein the anode catalyst layer is made of an anode catalyst.

7. The electrolysis apparatus as described in claim 6, characterized in that, The thickness of the cathode gas diffusion layer is 0.05 mm to 1.97 mm; and / or, The cathode catalyst is made of at least one metallic element selected from Ru, Au, Ag, Ir, Rh, Pd, Pt, Re, Ni, Mo, W, Mn, Co, Cu, Zn, and Al; and / or, The cathode catalyst layer further includes a first ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylquinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyetheretherketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyetheretherketone, and sulfonated polysulfone; and / or The loading of the cathode catalyst in the cathode is 0.1 mg / cm³. 2 -20mg / cm 2 .

8. The electrolysis apparatus as described in claim 6, characterized in that, The thickness of the anolyte gas diffusion layer is 0.1 mm to 2.46 mm; and / or, The anode catalyst is made of at least one metallic element selected from Ni, Fe, Co, Mn, Cu, Zn, Al, V, Cr, Mo, Ru, Au, Ag, Ir, Rh, Pd, Pt, and Re; and / or, The anode catalyst layer further includes a second ionomer, which is selected from at least one of the following: quaternized polysulfone polymer, quaternized polyphenylene ether polymer, quaternized polyarylpiperidine polymer, quaternized polyarylquinine polymer, quaternized polynorbornene polymer, quaternized polystyrene polymer, quaternized polybenzimidazole polymer, quaternized styrene-butadiene block copolymer, quaternized polyethylene polymer, quaternized polyetheretherketone, quaternized polyaryl N-methylpyridine, quaternized polyaryl N-methylpyrrolidine, perfluorosulfonic acid, sulfonated polystyrene, sulfonated polyetheretherketone, and sulfonated polysulfone; and / or The loading of the anode catalyst in the anode is 0.1 mg / cm³. 2 -20mg / cm 2 .

9. An electrolysis process, characterized in that, include: An electrolysis apparatus according to any one of claims 1-8 is provided, wherein an electrolyte is supplied to the anode side through a liquid supply structure in the electrolysis apparatus while the electrolyte is not supplied to the cathode side, and a voltage is applied to the cathode and the anode to perform electrolysis.

10. The electrolysis process as described in claim 9, characterized in that, The electrolyte is an aqueous solution containing an electrolyte, wherein the electrolyte includes at least one selected from KOH, NaOH, LiOH, K₂CO₃, KHCO₃, Na₂CO₃, and NaHCO₃, and the concentration of the electrolyte in the electrolyte is 0-7 mol / L; and / or The electrolysis temperature is 25℃-85℃.

11. An electrolysis apparatus, characterized in that, The device includes a cathode, an anode, and an anion exchange membrane. The thickness of the anode is greater than the thickness of the cathode. The anion exchange membrane is disposed between the cathode and the anode. During electrolysis, the electrolyte is introduced into the anode side while the electrolyte is not introduced into the cathode side.

12. A membrane electrode assembly, characterized in that, It includes a cathode, an anode, and an anion exchange membrane, wherein the thickness of the anode is greater than the thickness of the cathode, and the anion exchange membrane is disposed between the cathode and the anode.

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