Alkaline electrolytic water hydrogen production composite diaphragm capable of resisting fluctuation mechanical stress below power supply minute level as well as preparation method and application of alkaline electrolytic water hydrogen production composite diaphragm
By designing a composite diaphragm structure of a flexible base layer, a zirconia nanofiber reinforced layer and a nickel-doped polyphenylene sulfide functional layer, the mechanical damage caused by power supply fluctuations is solved, the mechanical stability and service life of the diaphragm are improved, and it is suitable for alkaline electrolytic water hydrogen production under dynamic power supply fluctuations.
Patent Information
- Application Number
- CN202510395423.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-08-08
AI Technical Summary
The existing alkaline water electrolytic hydrogen production membranes are prone to microcracks or perforations due to the uneven distribution of the electrolyte and concentrated mechanical stresses under the rapid fluctuation of the power supply minute level, resulting in gas cross-penetration, reduced efficiency and safety hazards.
An alkaline electrolytic water hydrogen-making composite separator that resists fluctuations below the power supply minute level is designed, and a laminated structure of a flexible base layer, a zirconia nanofiber reinforced layer and a nickel-doped polyphenylene sulfide functional layer is prepared by electrospinning and hot pressing forming to form a three-dimensional network structure to disperse stress.
It significantly improves the mechanical stability and durability of the diaphragm under dynamic power fluctuations, improves tensile strength, reduces gas cross-permeability, and prolongs service life. It is suitable for hydrogen production of volatile renewable energy sources.
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Figure CN120443256A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure belongs to the technical field of hydrogen production by electrolysis of water, and specifically relates to an alkaline composite diaphragm for hydrogen production by electrolysis of water that is resistant to mechanical stress fluctuations of a power source at the sub-minute level, as well as a preparation method and application thereof. Background Art
[0002] Diaphragm materials play a crucial role in alkaline water electrolysis hydrogen production technology. They not only isolate hydrogen generated at the cathode and oxygen generated at the anode, ensuring hydrogen purity and safe production, but also ensure the smooth passage of ions in the electrolyte to maintain the electrolysis process. Traditional diaphragm materials, such as asbestos, were once widely used commercially but have been banned by the World Health Organization due to their severe swelling behavior and carcinogenicity. Existing polyphenylene sulfide (PPS) fabric membranes, while offering excellent physical and chemical properties, still suffer from weak hydrophilicity and high internal resistance, necessitating urgent improvements. Treatments such as grafting, oxidation, sulfonation, and plasma treatments are needed to create a hydrophilic surface. However, treated PPS diaphragms primarily focus on corrosion resistance under static conditions. Under rapid power fluctuations, even at the minute level, microcracks or perforations can easily develop due to uneven electrolyte distribution and concentrated mechanical stress, leading to gas cross-permeation, reduced efficiency, and potential safety hazards. Summary of the Invention
[0003] The present disclosure aims to at least solve the problem of mechanical damage to the diaphragm caused by power supply fluctuations in the prior art, and to provide an alkaline water electrolysis hydrogen production composite diaphragm that is resistant to mechanical stress from power supply fluctuations of less than one minute, as well as a preparation method and application.
[0004] In one aspect of the present disclosure, there is provided an alkaline water electrolysis hydrogen production composite diaphragm capable of withstanding mechanical stress fluctuations of a power supply at the sub-minute level, the alkaline water electrolysis hydrogen production composite diaphragm comprising:
[0005] a flexible substrate layer having a first surface and a second surface disposed opposite to each other;
[0006] A reinforcement layer is located on the first surface and the second surface of the flexible base layer, wherein the reinforcement layer is zirconium oxide nanofiber;
[0007] The functional layer is located on the surface of the reinforcement layer, and the functional layer is nickel-doped polyphenylene sulfide.
[0008] Optionally, the flexible base layer is a polytetrafluoroethylene porous membrane.
[0009] Optionally, the polytetrafluoroethylene porous membrane has a thickness of 100-200 μm and a porosity of 60-70%.
[0010] Optionally, the reinforcement layer has a three-dimensional mesh structure.
[0011] Optionally, the diameter of the zirconia nanofiber is 50-100 nm.
[0012] Optionally, in the functional layer, the doping amount of nickel is 1-3 wt % of the polyphenylene sulfide content.
[0013] Optionally, the functional layer has a thickness of 10-30 μm.
[0014] Another aspect of the present disclosure provides a method for preparing the alkaline water electrolysis hydrogen production composite membrane described above, the method comprising:
[0015] Electrospinning a zirconium oxide precursor solution onto a flexible base layer, and forming zirconium oxide nanofibers on both sides of the flexible base layer through calcination to obtain a reinforcement layer;
[0016] The nickel-doped polyphenylene sulfide slurry is sprayed on the surface of the nanofiber reinforcement layer, and the functional layer is obtained through hot pressing and plasma surface treatment.
[0017] Optionally, the calcination temperature is 450-550° C. and the calcination time is 2-3 hours; and / or,
[0018] The temperature of the hot pressing forming process is 250-300° C. and the time is 0.5-1 hour.
[0019] Another aspect of the present disclosure provides an application of a composite membrane for producing hydrogen by alkaline water electrolysis, wherein the composite membrane for producing hydrogen by alkaline water electrolysis described above is applied to produce hydrogen by alkaline water electrolysis.
[0020] The present disclosure provides an alkaline water electrolysis hydrogen production composite diaphragm that is resistant to mechanical stress fluctuations of power supply at the sub-minute level, as well as a preparation method and application. The alkaline water electrolysis hydrogen production composite diaphragm includes: a flexible base layer having a first surface and a second surface arranged opposite to each other; a reinforcement layer located on the first surface and the second surface of the flexible base layer, the reinforcement layer being zirconium oxide nanofiber; a functional layer located on the surface of the reinforcement layer, the functional layer being nickel-doped polyphenylene sulfide. The present disclosure significantly improves the mechanical stability and durability of the diaphragm under dynamic power supply fluctuations by designing the composite diaphragm as a stacked structure of flexible base + nanofiber stress dispersion + functional coating, solves the problem of damage to traditional diaphragms caused by mechanical stress concentration, and provides reliable technical support for hydrogen production from fluctuating renewable energy. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 This is a flowchart of a method for preparing a composite diaphragm for producing hydrogen by alkaline water electrolysis that is resistant to mechanical stress fluctuations of power supply at the sub-minute level according to a specific embodiment of the present disclosure. DETAILED DESCRIPTION
[0022] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.
[0023] In one aspect of the present disclosure, a composite membrane for producing hydrogen by electrolyzing alkaline water, which is resistant to mechanical stress fluctuations of a power supply at the sub-minute level, is proposed. The composite membrane for producing hydrogen by electrolyzing alkaline water includes: a flexible base layer having a first surface and a second surface arranged opposite to each other; a reinforcement layer located on the first and second surfaces of the flexible base layer, the reinforcement layer being zirconium oxide nanofiber; and a functional layer located on the surface of the reinforcement layer, the functional layer being nickel-doped polyphenylene sulfide.
[0024] In this embodiment, by designing the composite diaphragm as a collaborative structure of flexible base layer + nanofiber reinforcement layer + functional layer, it is possible to disperse local stress, improve tensile strength and chemical corrosion resistance, etc., significantly improve the mechanical stability and durability of the diaphragm under dynamic power fluctuations, solve the damage problem of traditional diaphragms caused by mechanical stress concentration, and provide reliable technical support for hydrogen production from fluctuating renewable energy.
[0025] In some preferred embodiments, the flexible base layer may be made of a polytetrafluoroethylene (PTFE) porous membrane. This material has a certain porosity, and the porous structure ensures the permeability of ions and gases, providing sufficient attachment space for the reinforcement layer. It also has extremely strong acid and alkali resistance and can maintain structural stability in complex chemical environments.
[0026] As a further preferred solution, the thickness of the polytetrafluoroethylene porous membrane is 100-200 μm and the porosity is 60-70%. The above thickness range can make the flexible base layer have good tensile strength and improve the overall deformation resistance of the diaphragm.
[0027] In other preferred embodiments, the reinforcement layer comprises a three-dimensional mesh structure, distributed on opposite sides of the flexible base layer. This structure more evenly distributes localized stress, alleviating mechanical stress concentration in the diaphragm under dynamic operating conditions (such as power fluctuations), improving the diaphragm's mechanical stability, and reducing structural damage. Furthermore, because the reinforcement layer is a zirconia nanofiber layer, the material itself possesses excellent high-temperature resistance and chemical stability, ensuring excellent stability under complex operating conditions.
[0028] As a further preferred solution, the diameter of the zirconium oxide nanofiber is 50-100nm. The nanofiber has high strength and strong resistance to current shock, which helps to improve stability. At the same time, the high specific surface area of the nanofiber can improve the hydrophilicity of the diaphragm, provide a smoother path for ion conduction, improve ion transmission efficiency, and optimize the functionality of the diaphragm.
[0029] In other preferred embodiments, the thickness of the functional layer is 10-30 μm. It should be understood that reinforcement layers are provided on both sides of the flexible base layer. Thus, functional layers should be provided on the reinforcement layers on both sides, that is, the functional layer is wrapped on the reinforcement surface.
[0030] As a further preferred embodiment, the nickel doping amount in the functional layer is 1-3wt% of the polyphenylene sulfide (PPS) content, that is, the ratio of nickel content to polyphenylene sulfide content is 1-3:100, for example, preferably 2:100. This doping amount can effectively activate the ion conduction path while avoiding lattice distortion caused by excessive nickel content, ensuring the stability of the conduction efficiency. Nickel atom doping can change the electron cloud distribution of polyphenylene sulfide (PPS), forming an ion transmission channel and significantly improving the ion conductivity by ≥0.2S / cm. In addition, the nickel element forms a synergistic structure with PPS, constructing a more stable chemical interface in a corrosive environment, resisting ion erosion, and having good chemical corrosion resistance. In other words, the use of nickel-doped polyphenylene sulfide as a functional layer has good stability under current fluctuations.
[0031] like Figure 1 As shown, another aspect of the present disclosure provides a method S100 for preparing the alkaline water electrolysis hydrogen production composite membrane described above, comprising the following specific steps S110 to S120:
[0032] S110, electrostatically spinning a zirconium oxide precursor solution onto a flexible base layer, and forming zirconium oxide nanofibers on both sides of the flexible base layer through calcination to obtain a reinforcement layer.
[0033] In some preferred embodiments, the calcination temperature is 450-550° C. and the calcination time is 2-3 hours. For example, the calcination temperature may be 500° C. and the calcination time may be 2.5 hours.
[0034] It should be noted that the zirconia precursor solution includes zirconia and other additives, such as a PVP binder, to ensure uniform dispersion of zirconia particles in the ZrO2 precursor solution, preventing agglomeration and providing a stable and uniform raw material system for electrospinning. This also helps increase the solution's viscosity and flexibility, making it easier for the ZrO2 precursor solution to form continuous, uniform fibers during the electrospinning process, allowing them to be electrospun onto the PTFE substrate, forming a complete three-dimensional network structure.
[0035] S120, spraying nickel-doped polyphenylene sulfide slurry onto the surface of the nanofiber reinforcement layer, and performing hot pressing and plasma surface treatment to obtain a functional layer.
[0036] In some preferred embodiments, the temperature of the hot pressing process is 250-300° C., and the time is 0.5-1 hour. For example, the temperature may be 280° C., and the time may be 0.5 hour.
[0037] In this embodiment, hot pressing is used to fully fuse the nickel powder and PPS in the Ni-PPS slurry, forming a uniform and dense functional layer structure. This eliminates internal pores or defects, ensures the functional layer is firmly attached to the surface of the ZrO2 nanofiber layer, and fills the microscopic gaps through thermoplastic deformation, achieving stable formation of the functional layer. Furthermore, plasma post-treatment activates the surface, making it easier to chemically bond or physically entangle with adjacent layers. This significantly improves the interfacial bonding between the functional layer, reinforcement layer, and base layer, preventing delamination.
[0038] Another aspect of the present disclosure provides an application of a composite membrane for producing hydrogen by alkaline water electrolysis, wherein the composite membrane for producing hydrogen by alkaline water electrolysis described above is applied to produce hydrogen by alkaline water electrolysis.
[0039] In this embodiment, when the composite membrane is applied to alkaline water electrolysis for hydrogen production, under the condition of simulating minute-level current fluctuations (0-100% cycle), the tensile strength of the composite membrane is ≥30 MPa, which is higher than the tensile strength of the conventional membrane ≤15 MPa; secondly, under dynamic working conditions, the gas cross permeability of the composite isolation of this embodiment is reduced to 0.05 mL / (cm 2 ·min), which is lower than the gas cross permeability of traditional membranes ≥0.2mL / (cm 2 ·min); In addition, the composite isolation membrane of this embodiment has a service life extended to 8000 hours, significantly longer than the service life of conventional membranes of ≤3000 hours. In other words, the alkaline water electrolysis hydrogen production composite membrane provided by this embodiment has high tensile strength, low gas cross-permeability, and a long service life. It is able to withstand mechanical stress from power supply fluctuations of less than one minute, thereby solving the problem of mechanical damage to the membrane caused by power supply fluctuations and is suitable for use in dynamic power supply fluctuation conditions.
[0040] The preparation method and application of the composite diaphragm for hydrogen production by alkaline water electrolysis will be further described below with reference to specific examples:
[0041] Example 1
[0042] The method for preparing the composite diaphragm for producing hydrogen by alkaline water electrolysis in this example includes:
[0043] S1, preparing a PTFE porous substrate layer with a thickness of 150 μm and a porosity of 65%;
[0044] S2, using electrospinning technology to electrospin ZrO2 precursor solution (containing PVP binder) onto the substrate layer, calcined at 500 ° C, and after calcination, composited on both sides of PTFE to form a ZrO2 nanofiber layer with a fiber diameter of 80nm;
[0045] S3, spraying Ni-PPS slurry (nickel powder and PPS mass ratio of 1:50) on the surface of the ZrO2 layer, hot pressing at 280 ° C to form a Ni-PPS functional layer with a thickness of 20 μm, and plasma treatment after hot pressing;
[0046] Test conditions: 30% KOH solution, 80°C, current fluctuation period 1 minute (0-2A / cm 2 ), simulating minute-level current fluctuations (0-100% cycle).
[0047] The test results are as follows: Under simulated minute-level current fluctuations (0-100% cycle), the tensile strength of the diaphragm is ≥30MPa, the diaphragm has no cracks within 8000 hours, and the gas permeability is stable at 0.04mL / (cm 2 ·min).
[0048] Comparative Example 1
[0049] The conventional PPS diaphragm (without composite structure) was tested under the same test conditions as in Example 1. The results are as follows: micro cracks appeared after 3000 hours, and the permeability increased to 0.25 mL / (cm 2 ·min).
[0050] Comparative Example 2
[0051] The preparation method is the same as that of Example 1, except that the formation of the ZrO2 nanofiber layer in step S2 is removed. The diaphragm includes a base layer and Ni-PPS functional layers located on both sides of the base layer. It is tested under the same test conditions as Example 1, and the results are as follows: the tensile strength is reduced to 18 MPa, and local perforation occurs after 5000 hours.
[0052] In summary, by Example 1 and Comparative Example 1 comparative analysis, it is known that the composite diaphragm of PTFE base layer+ZrO nanofiber reinforced layer+Ni-PPS functional layer, by each layer synergistic effect, effectively enhances the gas barrier stability of diaphragm, can disperse stress, avoid mechanical stress concentration, be not easy to produce microcracks, can resist the rapid fluctuation environment below power supply minute level. By Example 1 and Comparative Example 2 comparative analysis, it is known that when lacking ZrO nanofiber layer, diaphragm tensile strength significantly decreases, which illustrates that ZrO nanofiber layer disperses stress by three-dimensional network structure, enhances diaphragm overall mechanical strength, and the stress dispersion system formed by its nanoscale fiber is the important basis for maintaining diaphragm high strength. In addition, in the diaphragm without ZrO layer, local perforation after 5000 hours, this illustrates that stress concentration problem occurs, cannot cope with the stress accumulation in long-term use, causes local structure destruction, further illustrates that ZrO nanofiber layer has the effect of dispersed stress, can avoid the damage problem that diaphragm causes because of mechanical stress concentration.
[0053] The present disclosure provides an alkaline water electrolysis hydrogen production composite diaphragm that can withstand mechanical stress fluctuations of power supply at the sub-minute level, as well as a preparation method and application thereof. Compared with the prior art, it has the following beneficial effects:
[0054] In response to the current lack of relevant existing technologies for diaphragms suitable for resisting dynamic mechanical stress: the composite diaphragm structure disclosed in the present invention includes a three-layer composite structure of a PTFE base layer, a ZrO2 nanofiber reinforcement layer and a Ni-PPS functional layer. Through the synergistic effect of each layer, it can effectively disperse stress, improve the mechanical stability and durability of the diaphragm under dynamic power supply fluctuations, and solve the damage problem of traditional diaphragms caused by mechanical stress concentration.
[0055] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.
Claims
1. A composite diaphragm for producing hydrogen from alkaline water electrolysis that is resistant to mechanical stress fluctuations of power supply at the sub-minute level, characterized in that: The alkaline water electrolysis hydrogen production composite diaphragm comprises: a flexible substrate layer having a first surface and a second surface disposed opposite to each other; A reinforcement layer is located on the first surface and the second surface of the flexible base layer, wherein the reinforcement layer is zirconium oxide nanofiber; The functional layer is located on the surface of the reinforcement layer, and the functional layer is nickel-doped polyphenylene sulfide.
2. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 1, characterized in that The flexible base layer is made of a polytetrafluoroethylene porous membrane.
3. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 2, characterized in that The thickness of the polytetrafluoroethylene porous membrane is 100-200 μm, and the porosity is 60-70%.
4. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 1, characterized in that The reinforcement layer has a three-dimensional network structure.
5. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 1, characterized in that: The diameter of the zirconium oxide nanofiber is 50-100 nm.
6. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 1, characterized in that: In the functional layer, the doping amount of nickel is 1-3 wt % of the content of polyphenylene sulfide.
7. The alkaline water electrolysis hydrogen production composite diaphragm according to claim 1, characterized in that: The thickness of the functional layer is 10-30 μm.
8. A method for preparing the composite membrane for producing hydrogen by alkaline water electrolysis according to any one of claims 1 to 7, characterized in that: The method comprises: Electrospinning a zirconium oxide precursor solution onto a flexible base layer, and forming zirconium oxide nanofibers on both sides of the flexible base layer through calcination to obtain a reinforcement layer; The nickel-doped polyphenylene sulfide slurry is sprayed on the surface of the nanofiber reinforcement layer, and the functional layer is obtained through hot pressing and plasma surface treatment.
9. The method according to claim 8, characterized in that The calcination treatment temperature is 450-550°C and the time is 2-3 hours; and / or, The temperature of the hot pressing forming process is 250-300° C. and the time is 0.5-1 hour.
10. An application of a composite diaphragm for hydrogen production by alkaline water electrolysis, characterized in that: The alkaline water electrolysis hydrogen production composite diaphragm according to any one of claims 1 to 7 is used in alkaline water electrolysis hydrogen production.