Proton exchange membrane electrolysis water membrane electrode edge sealing structure and manufacturing method

Abstract

The invention provides a proton exchange membrane electrolyzed water membrane electrode edge sealing structure which comprises a proton exchange membrane, a layer of anode inner frame, a layer of anode outer frame, a layer of cathode inner frame and a layer of cathode outer frame, and further provides a manufacturing method of the proton exchange membrane electrolyzed water membrane electrode edge sealing structure. Compared with the prior art, the invention has the following beneficial effects: the staggered edge sealing structure overcomes the defects of traditional symmetrical design from three core dimensions of pressure distribution, structural stability and long-term operation performance through structural innovation of size dislocation and multi-level distribution, and provides key support for long-term stable operation of the PEMWE membrane electrode; and the method is particularly suitable for high-reliability water electrolysis hydrogen production scenes.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of proton exchange membrane water electrolysis membrane electrode, and particularly relates to a proton exchange membrane water electrolysis membrane electrode edge sealing structure and a manufacturing method. BACKGROUND

[0002] At present, the edge sealing design of the PEMWE membrane electrode usually follows the edge sealing design of the fuel cell membrane electrode (the cathode and the anode are symmetrical inside and outside Figure 1 ). However, the membrane electrode edge sealing design can cause excessive local pressure of the edge sealing, which can cause the edge sealing to be opened after the electrolytic tank is operated for a long time, and then the air tightness is reduced, the local shear force of the edge sealing material is excessive, and then the fracture occurs and the like. These greatly affect the stability of the long-term operation of the PEMWE membrane electrode.

[0003] Therefore, aiming at the above problems, the application provides a misaligned membrane electrode edge sealing design, which relieves the problem of excessive local pressure of the edge sealing edge under the working condition, and provides a new idea for the long-term stability of the PEM hydrogen production membrane electrode. SUMMARY

[0004] In view of the defects in the prior art, the application aims to provide a proton exchange membrane water electrolysis membrane electrode edge sealing structure to solve the problems in the background art.

[0005] The application is implemented by the following technical scheme: a proton exchange membrane water electrolysis membrane electrode edge sealing structure, comprising a proton exchange membrane, an anode inner frame, an anode outer frame, a cathode inner frame and a cathode outer frame, wherein the anode inner frame and the cathode inner frame are respectively arranged on the outer side of the anode and the cathode of the proton exchange membrane, and the anode outer frame and the cathode outer frame are respectively arranged on the outer side of the anode inner frame and the cathode inner frame.

[0006] As a preferred embodiment, the length and width dimensions of the cathode inner frame are respectively 1-4 mm larger than the length and width dimensions of the cathode catalyst layer; the length and width dimensions of the cathode outer frame are respectively 4-8 mm larger than the length and width dimensions of the cathode inner frame. The length and width dimensions of the anode inner frame are respectively 1-4 mm larger than the length and width dimensions of the anode catalyst layer; the length and width dimensions of the anode outer frame are respectively 4-8 mm larger than the length and width dimensions of the anode inner frame.

[0007] As a preferred embodiment, the materials of the anode inner frame and the cathode inner frame are one of polyphenylene sulfide (PPS), polyvinyl fluoride (PVF), polyimide (PI) and polyethylene naphthalate (PEN). The materials of the anode outer frame and the cathode outer frame are polyethylene naphthalate (PEN).

[0008] As a preferred embodiment, the total thickness of the anode outer frame is 100-250 μm, and the total thickness of the cathode outer frame is 100-250 μm.

[0009] A manufacturing method of a proton exchange membrane water electrolysis membrane electrode edge sealing structure, comprising the following steps: step one, taking a 20 cm*20 cm 50 μm proton exchange membrane, respectively using 0.5 M sulfuric acid, 5% hydrogen peroxide, ultrapure water for soaking treatment of proton exchange membrane, remove surface impurities, after treatment, dry for standby; Step two, making a false membrane electrode without a catalyst layer, cutting a 148 mm*69 mm and 132 mm*53 mm 40 μm PPS as an anode inner frame and a cathode inner frame respectively; Cutting a 156 mm*78 mm and 140 mm*61 mm 250 μm PEN as an anode outer frame and a cathode outer frame respectively; Heat pressing at 160 ℃, 30 kg cm -2 Under the condition for 80 s, the proton exchange membrane and the above edge sealing material are edge sealed to obtain a membrane electrode without a catalyst layer, which is recorded as false membrane electrode 2; Step three, making a membrane electrode with a catalyst layer, specifically: the anode catalyst IrO2 and the cathode catalyst Pt / C are transferred to the proton exchange membrane using a transfer process, and the load of the anode and the cathode is controlled to be 1 mg cm -2 And 0.4 mg cm -2 The membrane electrode 2 is made using the same edge sealing design as step two.

[0010] After adopting the above technical scheme, the beneficial effects of the present application are: the edge sealing structure designed in a staggered manner solves the defects of the traditional symmetrical design from the three core dimensions of pressure distribution, structural stability and long-term operation performance through the structural innovation of "size stagger + multi-level distribution", and provides key support for the long-term stable operation of the PEMWE membrane electrode, especially suitable for the hydrogen production by water electrolysis scene which requires high reliability. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0012] Figure 1 The structure diagram of the prior art edge sealing (edge sealing mode 1).

[0013] Figure 2 The schematic diagram of the edge sealing structure (edge sealing method 2) of the application.

[0014] Figure 3 The pressure sensitive results of the active area of the two edge sealing methods.

[0015] Figure 4 The SEM pictures of the proton membranes after hot pressing at 160 degrees under the two edge sealing methods.

[0016] Figure 5 The membrane electrode activity comparison of the two edge sealing methods.

[0017] Figure 6 The membrane electrode stability data comparison of the two edge sealing designs at 3.5 A cm -2

[0018] In the figure, the proton exchange membrane (1), the anode inner frame (2), the anode outer frame (3), the cathode inner frame (4), and the cathode outer frame (5). DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the application.

[0020] Please refer to Figure 2 The application provides a technical solution: an edge sealing structure of a proton exchange membrane electrolysis water membrane electrode, which comprises a proton exchange membrane 1, an anode inner frame 2, an anode outer frame 3, a cathode inner frame 4, and a cathode outer frame 5. The anode inner frame 2 and the cathode inner frame 4 are respectively arranged on the outer side of the anode and the cathode of the proton exchange membrane 1, and the anode outer frame 3 and the cathode outer frame 5 are respectively arranged on the outer side of the anode inner frame 2 and the cathode inner frame 4.

[0021] The length and width dimensions of the cathode inner frame 4 are respectively 1-4 mm larger than those of the cathode catalyst layer, and the length and width dimensions of the cathode outer frame 5 are respectively 4-8 mm larger than those of the cathode inner frame 4. The length and width dimensions of the anode inner frame 2 are respectively 1-4 mm larger than those of the anode catalyst layer, and the length and width dimensions of the anode outer frame 3 are respectively 4-8 mm larger than those of the anode inner frame 2.

[0022] The materials of the anode inner frame 2 and the cathode inner frame 4 are one of polyphenylene sulfide (PPS), polyvinyl fluoride (PVF), polyimide (PI), and polyethylene naphthalate (PEN).​ The material of the anode outer frame 3 and the cathode outer frame 5 is polyethylene naphthalate (PEN).

[0023] The total thickness of the anode outer frame 3 is 100-250 μm, and the total thickness of the cathode outer frame 5 is 100-250 μm.

[0024] The application provides a technical scheme: a manufacturing method of a proton exchange membrane water electrolysis membrane electrode edge sealing structure, comprising the following steps: Step one, take a 20 cm*20 cm 50 μm proton exchange membrane 1, respectively use 0.5 M sulfuric acid, 5% hydrogen peroxide, ultrapure water to soak the proton exchange membrane 1, remove the surface impurities, and dry for use after the treatment is completed; Step two, according to the edge sealing design 2 attached Figure 2 , an edge sealing structure without a catalytic layer is manufactured, a 148 mm*69 mm and a 132 mm*53 mm 40 μm PPS are cut as an anode inner frame 2 and a cathode inner frame 4 respectively; A 156 mm*78 mm and a 140 mm*61 mm 250 μm PEN are cut as an anode outer frame 3 and a cathode outer frame 5 respectively; The proton exchange membrane 1 and the edge sealing material are edge sealed under the condition of 160 DEG C, 30 kg cm -2 -1 for 80 s to obtain a membrane electrode without a catalytic layer, which is marked as a false membrane electrode 2; Step three, a membrane electrode with a catalytic layer is manufactured, specifically: the anode catalyst IrO2 and the cathode catalyst Pt / C are transferred to the proton exchange membrane 1 using a transfer process, and the load of the anode and the cathode is controlled to be 1 mg cm -2 and 0.4 mg cm -2 respectively, and the membrane electrode 2 is manufactured using the same edge sealing design in step two.

[0025] Example 1, an edge sealing structure of the prior art is manufactured, like Figure 1 : comprising the following steps: Step one, take a 20 cm*20 cm 50 μm proton exchange membrane 1, respectively use 0.5 M sulfuric acid, 5% hydrogen peroxide, ultrapure water to soak the proton exchange membrane 1, remove the surface impurities, and dry for use after the treatment is completed; Step two, according to the edge sealing design 2 attached Figure 1The edge design 1 is used to make the membrane electrode without a catalytic layer, specifically: cutting two 148 mm*69 mm 40 μm polyphenylene sulfide (PPS) as the anode inner frame 2 and the cathode inner frame 4; cutting two 156 mm*77 mm 250 μm polyethylene naphthalate (PEN) as the anode outer frame 3 and the cathode outer frame 5; The proton exchange membrane 1 and the above edge material are edge sealed at 160 ℃, 30 kg cm -2 , to obtain a membrane electrode without a catalytic layer, denoted as membrane electrode 1. Step three, making a membrane electrode with a catalytic layer, specifically: using the transfer process to transfer the anode catalyst IrO2 and the cathode catalyst Pt / C to the proton exchange membrane, and controlling the load of the anode and the cathode to be 1 mg cm -2 and 0.4 mg cm -2 , respectively, and using the same edge sealing design as in step two to make the membrane electrode 1.

[0026] In the drawings mentioned in the following examples, a is the prior art edge sealing (edge sealing method 1), and b is the edge sealing structure of the present application (edge sealing method 2).

[0027] Based on the prior art edge sealing method in Example 1 and the edge sealing method of the present application, Example 2 is proposed, and the active area pressure sensitive results of the membrane electrode are tested by a cold press. Take the membrane electrode 1 and the membrane electrode 2, use 450 um carbon paper as the cathode GDL and 250 um titanium felt as the anode PTL, assemble the membrane electrode 1 and 2 with the above GDL and PTL, and pad the pressure sensitive paper on the anode side, and cold press at 25 ℃, 20 kg cm-2 for 120 s. Finally, the active area pressure distribution of the edge sealing method 1 and the edge sealing method 2 is obtained, as shown in the accompanying Figure 3 , it can be seen that the active area pressure distribution of the present application is more uniform, and the local excessive pressure on the edge sealing material is significantly reduced.

[0028] Based on the prior art edge sealing method in Example 1 and the edge sealing method of the present application, Example 3 is proposed, and the proton membrane SEM test characterization of the membrane electrode is carried out. Take the membrane electrode 1 and the membrane electrode 2, use 450 um carbon paper as the cathode GDL and 250 um titanium felt as the anode PTL, assemble the membrane electrode 1 and 2 with the above GDL and PTL. After assembly, hot press at 160 ℃, 10 kg cm-2 for 1 h. After hot pressing, the edge sealing material of the membrane electrode is removed, and the SEM test of the hot pressed proton exchange membrane is carried out, and the results are shown in the accompanying Figure 4As shown, due to excessive local pressure, the traditional design is prone to problems such as edge opening and material shear fracture during long-term operation. The staggered design reduces the risk of such failures by optimizing the structure and pressure distribution: The staggered inner and outer edge layer design disperses stress to multiple layers, reducing the load on a single edge layer.

[0029] Proton membrane SEM tests (Figure 4) show that the staggered design of the inventive structure after hot pressing has less damage (such as more uniform membrane thickness and no obvious local extrusion deformation), indicating better protection of the core components and indirectly reducing the problem of reduced air tightness due to structural damage.

[0030] Based on the existing edge sealing method in Example 1, and the edge sealing method of the present application, Example 4 is proposed, which is based on the PEMWE polarization curve test and durability test of membrane electrode 1 and 2 of edge sealing design 1 and edge sealing design 2. Take membrane electrode 1 and membrane electrode 2, use 10 Nm torque to assemble the electrolytic cell, the test temperature is 80 ℃, the results are shown in Figure 5. Figure 4 After the polarization curve test, durability test was carried out at a current density of 3.5 A cm-2, and the results are shown in Figure 6. Figure 6

[0031] Long-term stability is a key performance indicator of PEMWE membrane electrodes, and the staggered design performs better in this regard: Durability test (Figure 6) shows that at a current density of 3.5 A cm⁻², the performance of the staggered design membrane electrode (edge sealing design 2) decays more slowly (such as higher voltage maintenance) after long-term operation, while the performance of the traditional design (edge sealing design 1) decreases more obviously.

[0032] This result is due to the staggered design reducing problems such as edge opening and material fracture, avoiding the chain reaction of electrolyte leakage and reaction efficiency reduction caused by reduced air tightness or structural damage.

[0033] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.​

Claims

1. A proton exchange membrane water electrolysis membrane electrode edge sealing structure, comprising a proton exchange membrane (1), an anode inner frame (2), an anode outer frame (3), a cathode inner frame (4), and a cathode outer frame (5), characterized in that: The anode inner frame (2) and cathode inner frame (4) are respectively placed on the outside of the anode and cathode of the proton exchange membrane (1); the anode outer frame (3) and cathode outer frame (5) are respectively placed on the outside of the anode inner frame (2) and cathode inner frame (4); The length and width of the cathode inner frame (4) are respectively 1-4 mm larger than the length and width of the cathode catalyst layer; the length and width of the cathode outer frame (5) are respectively 4-8 mm larger than the length and width of the cathode inner frame (4); The length and width of the anode inner frame (2) are respectively 1-4 mm larger than the length and width of the anode catalyst layer; the length and width of the anode outer frame (3) are respectively 4-8 mm larger than the length and width of the anode inner frame (2).

2. A proton exchange membrane water electrolysis membrane electrode edge sealing structure according to claim 1, characterized in that: The material of the anode inner frame (2) and the cathode inner frame (4) is one of polyphenylene sulfide (PPS), polyvinyl fluoride (PVF), polyimide (PI), and polyethylene naphthalate (PEN); The material of the anode outer frame (3) and the cathode outer frame (5) is polyethylene naphthalate (PEN).

3. A proton exchange membrane water electrolysis membrane electrode edge sealing structure according to claim 2, characterized in that: The thickness of the proton exchange membrane (1) is 30-120 μm, the thickness of the inner frame of the anode (2) is 40-50 μm, and the thickness of the inner frame of the cathode (4) is 40-50 μm.

4. A proton exchange membrane water electrolysis membrane electrode edge sealing structure according to claim 3, characterized in that: The total thickness of the anode outer frame (3) is 100-250 μm, and the total thickness of the cathode outer frame (5) is 100-250 μm.

5. A method for manufacturing a proton exchange membrane water electrolysis membrane electrode edge sealing structure according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Take a 20 cm*20 cm 50 μm proton exchange membrane (1), soak it in 0.5 M sulfuric acid, 5% hydrogen peroxide, and ultrapure water, respectively, to remove surface impurities. After the treatment is completed, dry it for use; Step 2: Make a fake membrane electrode without a catalytic layer, cutting a 148 mm*69 mm and a 132 mm*53 mm piece of 40 μm PPS as the inner frame of the anode (2) and the inner frame of the cathode (4), respectively; Cut a piece of 250 μm PEN with a size of 156 mm*78 mm and a size of 140 mm*61 mm as the outer frame of the anode (3) and the outer frame of the cathode (5), respectively; At 160 °C and 30 kg cm -2 Hot pressing was performed for 80 s under the same conditions, and the proton exchange membrane (1) and the inner and outer frames were sealed to obtain a membrane electrode without a catalytic layer, which was recorded as a pseudo membrane electrode B; Step 3: Prepare a membrane electrode with a catalytic layer. Specifically, transfer the anode catalyst IrO2 and the cathode catalyst Pt / C to the proton exchange membrane (1) using a transfer process, and control the loading of the anode and cathode to 1 mg cm -2 and 0.4 mg cm -2 , use the same edge sealing method as in step 2 above to make membrane electrode B.

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