Structure for preventing anion exchange membrane from being punctured and damaged

Abstract

The utility model relates to a structure for preventing an anion exchange membrane from being punctured and damaged. The structure comprises a polyimide film and the anion exchange membrane, two square holes are symmetrically formed in the polyimide film; and the polyimide film is folded and the anion exchange membrane is embedded between the two square holes. The device is simple in structure and easy to implement, can stably prevent the foam nickel-based catalyst from puncturing the AEM, does not affect the catalytic performance of the AEM, and prolongs the service life of the membrane.

Description

TECHNICAL FIELD

[0001] The utility model relates to electrolytic water hydrogen production field especially, relate to a kind of structure to avoid anion exchange membrane puncture and damage. BACKGROUND

[0002] Hydrogen (H2) is becoming a promising energy carrier with its clean, abundant and high energy density characteristics. H2 is an important energy source that can generate energy and be stored for future use, thereby alleviating the energy problems caused by the use of non-renewable resources.

[0003] Water electrolysis using intermittent electricity generated from sustainable energy sources such as solar and wind power can achieve large-scale green hydrogen production. Currently, there are four main types of water electrolysis technologies: alkaline water electrolysis (AWE), solid oxide electrolysis cell (SOEC), proton exchange membrane water electrolysis (PEMWE) and anion exchange membrane water electrolysis (AEMWE). Among them, AEMWE is an emerging energy conversion technology that can produce H2 from water at low temperatures (such as 20-80 ℃), while perfectly combining the low cost of traditional alkaline water electrolysis (AWE) and the high energy efficiency, high current density and high H2 purity of proton exchange membrane water electrolysis (PEMWE). AEMWE is considered the most promising technology for water electrolysis hydrogen production and has attracted widespread attention in recent years.

[0004] In practical applications, a good substrate is crucial for AEMWE and should meet the functions and roles of supporting catalysts, transferring gas and electrons. In this case, metal foam (such as nickel foam, iron foam and copper foam) is one of the most popular substrates for AEMWE. However, due to the nature of anion exchange membrane (AEM) itself and the sharp structure of the foam surface, nickel foam (NF) is very easy to puncture the membrane in practical applications, leading to gas exchange between the two poles and short circuit of the AEMWE system, which further affects the performance of AEMWE. Therefore, it is crucial and practically significant to develop high-energy efficiency AEMWE electrolytic cells by designing the structure of AEMWE, selecting inexpensive and low-cost NF as the porous diffusion layer while considering the integrity and stability of AEM. SUMMARY

[0005] The technical problem to be solved by the utility model is to provide a structure that avoids anion exchange membrane puncture and damage while considering integrity and stability.

[0006] To solve the above problems, the structure for avoiding anion exchange membrane puncture and damage according to the utility model has the following characteristics: the structure includes a polyimide film and an anion exchange membrane; two square holes are symmetrically formed on the polyimide film; the polyimide film is folded and the anion exchange membrane is embedded between the two square holes.

[0007] The specification of the anion exchange membrane is 2.2mm*2.2mm.

[0008] The specification of the square hole is 2mm*2mm.

[0009] Compared with the prior art, the utility model has the following advantages:

[0010] 1、The polyimide film of the utility model is folded and makes the anion exchange membrane embedded between two square holes, can avoid the foam nickel-based catalyst to AEM puncture effect stably, and does not affect its catalytic performance, enhances the service life of membrane.

[0011] 2、The utility model has simple structure, easy to operate. DETAILED DESCRIPTION OF THE INVENTION

[0012] The specific embodiment of the utility model will be further explained in detail in combination with the drawings.

[0013] Figure 1 It is the structural schematic diagram of the utility model.

[0014] Figure 2 It is the structural schematic diagram of the polyimide film in the utility model.

[0015] Figure 3 It is the AEM WE device schematic drawing of introducing Pi film in the utility model.

[0016] Figure 4 It is the XRD image of foam nickel (NF) and NiMo / NF catalyst in the utility model.

[0017] Figure 5 It is the SEM image of NF and NiMo / NF catalyst in the utility model.

[0018] Figure 6 It is the SEM section image of introducing Pi film and not introducing Pi film in the utility model.

[0019] Figure 7 It is the XPS image of NiMo / NF catalyst in the utility model, wherein: the left drawing is Mo 3d spectrogram, and the right drawing is Ni 2p spectrogram.

[0020] Figure 8 It is the LSV curve of the device (left) of introducing Pi film and the device (right) of not introducing Pi film in the utility model.

[0021] Figure 9 It is the EIS curve of the device of introducing Pi film and the device of not introducing Pi film in the utility model.

[0022] Figure 10The polarization curve of a device with the Pi film introduced and a device without the Pi film introduced.

[0023] Figure 11 The electrochemical stability test image of the AEMWE device with the Pi film introduced.

[0024] In the figure: 1 - polyimide film; 2 - anion exchange membrane; 3 - square hole. DETAILED DESCRIPTION

[0025] As Figures 1-2 shown, a structure for avoiding anion exchange membrane puncture and damage, the structure includes polyimide film (Pi film) 1 and anion exchange membrane (AEM) 2; two square holes 3 are symmetrically provided on the polyimide film 1; the polyimide film 1 is folded and the anion exchange membrane 2 is embedded between the two square holes 3.

[0026] Among them: the specification of the anion exchange membrane 2 is 2.2mm*2.2mm.

[0027] The specification of the square hole 3 is 2mm*2mm. EMBODIMENT

[0028] NF (1.6 nm) is used as the anode catalyst of the AEMWE device, the electrochemically deposited NiMo / NF is used as the cathode catalyst, the commercial Sustainion X37-50 (50 μm) is used as the anion exchange membrane of the MEA system, and the polytetrafluoroethylene (PTFE) gasket-NF-Pi film-X37-50-Pi film-NiMo / NF-PTFE is sequentially loaded into the AEMWE device, and the system schematic diagram is as shown in Figure 3 .

[0029] Figure 3 is the AEMWE system schematic diagram after introducing the Pi film, the gasket is first placed on the anode current collector plate. Then, the NF (2 cm*2 cm) is placed in the gasket cutout, then the Pi film is placed on the top of the existing layer, then the X37-50 anion exchange membrane and the Pi film are placed, and finally the NiMo / NF cathode catalyst with the same area size is placed in the center of the gasket cutout without touching the gasket. The whole process needs to ensure that the gasket height is consistent with the catalyst height, so as to avoid water leakage of the device.

[0030] The prepared NF and NiMo / NF catalyst are characterized by X-ray diffraction (XRD), and the graph is as shown in Figure 4As shown in the XRD patterns, both NF and NiMo / NF exhibit three sharp peaks centered at 44.5°, 51.8°, 76.2°, and 92.7°. These peaks correspond to the standard pattern of metallic Ni (PDF#04-0850). The XRD results indicate that the substrate material is nickel foam, and the absence of characteristic peaks for metallic Mo is likely due to the low Mo content in the electrodeposited substrate.

[0031] The prepared NF and NiMo / NF catalysts were characterized by scanning electron microscopy (SEM), and the images are shown below. Figure 5 As shown in the figure, SEM results indicate the presence of distinct Mo metal particles on the NiMo / NF nickel foam after electrodeposition, demonstrating the successful electroplating synthesis of the NiMo / NF catalyst on the nickel foam substrate.

[0032] The AEM film after the reaction was characterized by cross-sectional scanning electron microscopy (SEM), and the image is shown below. Figure 6 As shown in the figure. SEM results indicate that the AEM film deformation decreased after the introduction of the Pi film, suggesting that the Pi film can alleviate the pressure exerted on the film by the nickel foam substrate.

[0033] The prepared NiMo / NF catalyst was characterized by X-ray photoelectron spectroscopy (XPS), and the resulting pattern is shown below. Figure 7 As shown. XPS results indicate that the three fitted peaks of NiMo / NF at 235.5 / 232.4 and 231.0 eV in the Mo 3d spectrum belong to hexavalent Mo and electroplated elemental Mo, respectively; the five peaks at 879.6 / 861.5, 873.8 / 856.2 and 851.9 eV in the Ni 2p spectrum correspond to satellite peaks, and Ni... 2+ The presence of elemental Ni indicates that the NiMo / NF catalyst was successfully synthesized by electroplating on a nickel foam substrate.

[0034] The prepared NF and NiMo / NF catalysts were then... Figure 3 The process was incorporated into the AEMWE device, and the electrolytic cell performance was tested at 80 °C and 1 M KOH, with a time of 5 mV s. −1 Linear scanning voltammetry (LSV) tests were performed at a scanning rate of [value missing], and the LSV curve is shown below. Figure 8 As shown in the figure. LSV results indicate that the AEMWE device without the Pi film has a very high current density and is in a short-circuit state, while the device functions normally after the Pi film is added.

[0035] The assembled device was subjected to electrochemical impedance spectroscopy (EIS) testing at a test voltage of 1.6 V, with a frequency range of 100,000–0.1 Hz. The results are as follows: Figure 9EIS results show that the EIS data of AEMWE devices without Pi film fluctuate greatly, and the devices are in short-circuit state, while the devices with Pi film are normal.

[0036] The assembled devices were measured by chronoamperometry (CP) to measure polarization curves, 17 current gradients were set from 0.01 A cm -2 to 1 A cm -2 with each current lasting for 30 s, and the voltage data of stable test were taken, and the results are shown in Figure 10 Polarization curves show that the cell voltage of AEMWE devices without Pi film is significantly lower than that of devices with Pi film (only 0.189 V at 1 A cm -2 current density), and the overall surface resistance is small, and the devices are in short-circuit state, while the devices with Pi film are normal (2.717 V at 1 A cm -2 current density).

[0037] The assembled devices were tested for stability by constant current charging mode of charge-discharge instrument at 80°C, at a current density of 1 A cm -2 , and the results are shown in Figure 11 The results show that the introduction of Pi film does not affect the stability of AEMWE system, and the system has excellent stability.

Claims

1. A structure that avoids puncture and damage to anion exchange membranes, characterized in that: The structure includes a polyimide film (1) and an anion exchange membrane (2); two square holes (3) are symmetrically opened on the polyimide film (1); the polyimide film (1) is folded in half and the anion exchange membrane (2) is embedded between the two square holes (3).

2. The structure for avoiding puncture and damage to anion exchange membranes as described in claim 1, characterized in that: The anion exchange membrane (2) has a size of 2.2 mm × 2.2 mm.

3. The structure for avoiding puncture and damage to anion exchange membranes as described in claim 1, characterized in that: The square hole (3) has a size of 2mm × 2mm.

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