Water electrolysis hydrogen production device and membrane electrode assembly and exchange membrane thereof

Abstract

The embodiment of the invention provides a water electrolysis hydrogen production device and a membrane electrode assembly and an exchange membrane thereof. The water electrolysis hydrogen production device comprises an anode end plate, an anode current collector, a membrane electrode assembly, a cathode current collector and a cathode end plate. The membrane electrode assembly comprises an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer and a cathode diffusion layer, wherein the exchange membrane comprises a first thin film and a second thin film. The first thin film is a perfluorinated proton exchange membrane, the second thin film is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 [mu] m. According to the technical scheme provided by the invention, the use of fluorine-containing substances can be effectively reduced on the premise of not influencing the electrochemical performance, so that the impact of the fluorine-containing substances on the ecological environment is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis of water, and in particular to a hydrogen production device by electrolysis of water, and its membrane electrode assembly and exchange membrane. Background Art

[0002] Proton exchange membrane (PEM) water electrolysis hydrogen production technology is the most suitable hydrogen production technology for renewable energy and the mainstream technical route for green electricity hydrogen production. During the PEM water electrolysis process, hydrogen produced at the cathode, due to concentration diffusion, passes through the proton exchange membrane and enters the anode, where it mixes with the oxygen produced at the anode. This not only increases the hydrogen concentration in the oxygen, but also easily reduces the safety of the electrolyzer operation.

[0003] Currently, proton exchange membranes are mainly made of perfluorosulfonic acid solid polymers. This material has high proton conductivity, low gas permeability and good chemical stability. However, perfluorosulfonic acid proton exchange membranes (PFAS) pose a great threat to the environment and human health. PFAS is extremely stable and not easily degraded naturally. It can remain in the environment for a long time and migrate over long distances through media such as air, water and soil, polluting the environment. For human health, after PFAS enters the human body, it may interfere with the human endocrine system, leading to hormone imbalances and increasing the risk of various health problems. Specifically, PFAS exposure is associated with abnormal thyroid function, decreased fertility, liver damage, kidney disease and an increased risk of certain types of cancer. Therefore, it is crucial to reduce the use of PFSA membranes.

[0004] Hydrocarbon membranes are a new material with broad application prospects. Composed primarily of carbon and hydrogen compounds, they are typically prepared using methods such as chemical vapor deposition. Hydrocarbon membranes exhibit excellent barrier properties, significantly reducing their water vapor transmission rate. Furthermore, they possess high mechanical strength and low gas transmission rate. They are also considered environmentally friendly, primarily due to their reduced environmental impact during production, use, and recycling. Compared to traditional fluorosulfonic acid membranes, hydrocarbon membranes do not contain toxic perfluorinated compounds, which are known environmental toxins that can leach into water sources and accumulate in organisms, making them difficult to recycle. Hydrocarbon membranes are produced using environmentally friendly hydrocarbon materials, avoiding the environmental issues associated with traditional materials. However, their poor chemical stability and susceptibility to oxidation at the anode preclude their large-scale use. The anode side of an electrolyzer is often damaged by the presence of strong oxidizing groups such as hydroxyl radicals (OH*), while the cathode, typically in a reducing environment, is immune to oxidation.

[0005] Therefore, in the production of hydrogen by electrolysis of water, reducing the use of perfluorosulfonic acid membranes while ensuring the safe operation of the electrolyzer is an issue that needs to be urgently addressed. Summary of the Invention

[0006] Various aspects of the present application provide a water electrolysis hydrogen production device, a membrane electrode assembly, and an exchange membrane thereof, to solve one or more of the above-mentioned problems.

[0007] An embodiment of the present application provides a water electrolysis hydrogen production device, comprising: an anode end plate, an anode current collector, a cathode current collector, a cathode end plate, and a membrane electrode assembly disposed between the anode current collector and the cathode current collector. The membrane electrode assembly comprises an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer, and a cathode diffusion layer arranged in sequence from the anode current collector toward the cathode current collector, wherein the exchange membrane comprises a first membrane and a second membrane in contact with each other. The first membrane is a perfluorinated proton exchange membrane, and the second membrane is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 μm.

[0008] In some embodiments of the present application, the thickness of the first film is not greater than the thickness of the second film.

[0009] In some embodiments of the present application, the thickness of the first film is 30-50 μm, and the thickness of the second film is 30-120 μm.

[0010] The present application also provides a membrane electrode assembly for a water electrolysis hydrogen production device, comprising an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer, and a cathode diffusion layer, wherein the exchange membrane comprises a first membrane and a second membrane in contact with each other. The first membrane is a perfluorinated proton exchange membrane, and the second membrane is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 μm.

[0011] The present application also provides an exchange membrane for a water electrolysis hydrogen production device, comprising a first membrane and a second membrane in contact with each other. The first membrane is a perfluorinated proton exchange membrane, and the second membrane is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the membrane thickness is 60-170 μm.

[0012] In an embodiment of the present application, the exchange membrane of the electrolytic water hydrogen production device includes a first film and a second film in contact, wherein the first film is a perfluorinated proton exchange membrane, and the second film is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane. In the exchange membrane of the embodiment of the present application, due to the close combination between the two layers of film, there is only a very small gap under the action of swelling, so that when the total thickness of the double-layer film is equal to the thickness of the single-layer film of the existing electrolytic water device, the existing electrochemical properties are still retained. At the same time, since the second film adopts the configuration of a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, the electrolytic water hydrogen production device provided in the embodiment of the present application can effectively reduce the use of fluorinated substances and reduce the impact on the ecological environment without affecting the electrochemical performance, and therefore has both commercial application value and beneficial effects such as environmental sustainability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0014] Figure 1 It is a plan view of an existing water electrolysis hydrogen production device.

[0015] Figure 2 and Figure 3 They are respectively plan schematic diagrams of the water electrolysis hydrogen production device according to the embodiments of the present application.

[0016] Figure 4 This is the electrochemical performance diagram of the existing water electrolysis hydrogen production device.

[0017] Figure 5 This is an electrochemical performance diagram of the water electrolysis hydrogen production device according to an embodiment of the present application.

[0018] Figure 6 This is a diagram of the hydrogen content in oxygen in an existing water electrolysis hydrogen production device.

[0019] Figure 7 This is a diagram of the hydrogen content in oxygen of the water electrolysis hydrogen production device according to an embodiment of the present application. DETAILED DESCRIPTION

[0020] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0021] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0022] See also Figure 2 and Figure 3 The present invention provides an electrolytic water hydrogen production device 1, comprising an anode end plate 10, an anode current collector 20, a cathode current collector 30, a cathode end plate 40, and a membrane electrode assembly 50. The anode current collector 20, the cathode current collector 30, and the membrane electrode assembly 50 are sandwiched between the anode end plate 10 and the cathode end plate 40. The anode end plate 10 is provided with a water inlet and a water outlet, and the cathode end plate 40 is provided with a water outlet. The water inlet is used to allow the inflow of electrolyte raw liquid, the water outlet is used to allow the oxygen-rich electrolyte to flow out after the hydrogen production reaction is completed, and the water outlet is used to allow the hydrogen-rich electrolyte to flow out after the hydrogen production reaction is completed. The anode current collector 20 is located on one side of the anode end plate 10, the cathode current collector 30 is located on one side of the cathode end plate 40, the membrane electrode assembly 50 is located between the anode current collector 20 and the cathode current collector 30, and a bipolar plate 60 is provided between two adjacent membrane electrode assemblies 50 among the multiple membrane electrode assemblies 50.

[0023] Figure 3 The simplified structure of the water electrolysis hydrogen production device 1 provided in an embodiment of the present application, wherein the membrane electrode assembly 50 includes an anode diffusion layer 510, an anode catalyst layer 520, an exchange membrane 530, a cathode catalyst layer 540 and a cathode diffusion layer 550, which are arranged in sequence from the anode current collector 20 to the cathode current collector 30, so that the anode diffusion layer 510 corresponds to the anode current collector 20, the cathode diffusion layer 550 corresponds to the cathode current collector 30, and the exchange membrane 530 is interposed between the anode catalyst layer 520 and the cathode catalyst layer 540.

[0024] The exchange membrane 530 includes a first membrane 531 and a second membrane 532 in contact with each other, and the thickness of the exchange membrane 530 is 60-170 μm. That is, the sum of the thickness of the first membrane 531 and the thickness of the second membrane 532 is 60-170 μm, which is approximately equal to the thickness of a single perfluorosulfonic acid membrane used in existing water electrolysis hydrogen production devices. For example, in some embodiments of the present application, the first membrane 531 can be a thinner perfluorosulfonic acid proton exchange membrane, such as a fluorosulfonic acid proton exchange membrane (PFAS), and the second membrane 532 can be a thicker membrane combined with a thicker partially fluorinated polymer proton exchange membrane or a non-fluoropolymer proton exchange membrane, such as a hydrocarbon membrane.

[0025] In the water electrolysis hydrogen production device 1 provided in some embodiments of the present application, the first film 531 of the exchange membrane 530 adopts a perfluorinated proton exchange membrane with a thickness of 30-50 μm, such as a fluorosulfonic acid type (PFSA) proton exchange membrane with a thickness of 40 μm and a conductivity of 100 mS / cm. The second film 532 of the exchange membrane 530 adopts a hydrocarbon membrane with a thickness of 30-120 μm. In some test embodiments of the present application, a sulfonated polyetheretherketone (sPEEK) proton exchange membrane with a thickness of 50 μm (with a conductivity of 120 mS / cm) is used as an example, but is not limited to this. Among them, the first film 531 (i.e., the PFSA proton exchange membrane) and the anode catalyst (IrO X / TiO2) is bonded as the anode, the second film 532 (i.e., sPEEK proton exchange membrane) is bonded with the cathode catalyst (Pt / C) as the cathode, the anode diffusion layer 510 is composed of titanium felt (0.2 mm, porosity 65%), and the cathode diffusion layer is composed of carbon paper (0.2 mm, porosity 65%).

[0026] The control group was Figure 1 The conventional water electrolysis hydrogen production device shown in the figure adopts a 90 μm thick PFSA proton exchange membrane (conductivity 100 mS / cm), wherein one side of the PFSA proton exchange membrane is connected to the anode catalyst (IrO X / TiO2) is bonded to the anode, and the other side is bonded to the cathode catalyst (Pt / C) to serve as the cathode. The other conditions are consistent with those of the second embodiment of the present application.

[0027] The above two were electrolyzed in pure water (conductivity 0.1μS / cm) at 60℃, and the electrochemical performance and hydrogen in oxygen data were obtained as follows: Figure 4-7 shown.

[0028] Figure 4 This is the electrochemical performance diagram of the existing water electrolysis hydrogen production device. Figure 5 This is the electrochemical performance diagram of the water electrolysis hydrogen production device according to the embodiment of the present application. Figure 4 and Figure 5 As shown, the electrochemical performance of the water electrolysis hydrogen production device provided in the embodiment of the present application is basically consistent with the electrochemical performance of the existing water electrolysis hydrogen production device.

[0029] Therefore, the exchange membrane of the embodiment of the present application adopts a thinner perfluorinated proton exchange membrane as the first membrane, and a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane as the second membrane, and the total thickness is consistent with the thickness of the existing single-layer proton exchange membrane. This configuration can reduce the use of fluorine products and reduce the impact on the ecological environment without affecting the performance of the membrane. At the same time, in the embodiment of the present application, the surface of the second membrane is compounded with a cathode catalyst as a cathode, and the surface of the first membrane is compounded with an anode catalyst as an anode. This avoids the second membrane (such as a hydrocarbon membrane) being in an oxidizing environment, ensuring its chemical stability, and there is no need to worry about the problem of insufficient mechanical strength of the thinner first membrane.

[0030] In addition, if Figure 6 and Figure 7 As shown, Figure 6 This is a diagram of the hydrogen content in oxygen in an existing water electrolysis hydrogen production device. Figure 7 This is a graph showing the hydrogen content in oxygen for the electrolytic hydrogen production device according to an embodiment of the present application. Furthermore, under the same current density, the electrolytic hydrogen production device according to an embodiment of the present application, due to the use of a double-layer thin film exchange membrane, can effectively reduce the hydrogen content mixed with oxygen on the anode side, thereby eliminating the hidden danger of hydrogen-oxygen mixing.

[0031] Based on the above, the water electrolysis hydrogen production device provided in the embodiment of the present application not only reduces the use of fluorine products and reduces the harm to the environment and human health without affecting the membrane performance, but also can effectively reduce the hydrogen content mixed in the oxygen on the anode side, while at the same time having the effect of eliminating the hidden dangers of hydrogen and oxygen mixing.

[0032] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A water electrolysis hydrogen production device, characterized in that: include: An anode end plate, an anode current collector, a cathode current collector, a cathode end plate, and a membrane electrode assembly arranged between the anode current collector and the cathode current collector, wherein the membrane electrode assembly includes an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer, and a cathode diffusion layer arranged in sequence from the anode current collector toward the cathode current collector, wherein the exchange membrane includes a first film and a second film in contact with each other, the first film is a perfluorinated proton exchange membrane, and the second film is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 μm.

2. The water electrolysis hydrogen production device according to claim 1, characterized in that The thickness of the first film is not greater than the thickness of the second film.

3. The water electrolysis hydrogen production device according to claim 2, characterized in that: The thickness of the first film is 30-50 μm, and the thickness of the second film is 30-120 μm.

4. A membrane electrode assembly for a water electrolysis hydrogen production device, characterized in that: include: An anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer and a cathode diffusion layer are arranged in sequence, wherein the exchange membrane includes a first membrane and a second membrane in contact with each other, the first membrane is a perfluorinated proton exchange membrane, and the second membrane is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 μm.

5. The membrane electrode assembly according to claim 4, wherein: The thickness of the first film is not greater than the thickness of the second film.

6. The membrane electrode assembly according to claim 5, wherein: The thickness of the first film is 30-50 μm, and the thickness of the second film is 30-120 μm.

7. An exchange membrane for a water electrolysis hydrogen production device, characterized in that: The invention comprises a first membrane and a second membrane in contact with each other, wherein the first membrane is a perfluorinated proton exchange membrane, the second membrane is a partially fluorinated polymer proton exchange membrane or a non-fluorinated polymer proton exchange membrane, and the thickness of the exchange membrane is 60-170 μm.

8. The exchange membrane according to claim 7, characterized in that The thickness of the first film is not greater than the thickness of the second film.

9. The exchange membrane according to claim 8, characterized in that The thickness of the first film is 30-50 μm, and the thickness of the second film is 30-120 μm.

Images