Membrane electrode and preparation method thereof, and electrolytic cell for proton exchange membrane water electrolysis

Abstract

The present invention discloses a membrane electrode, a method for preparing the same, and an electrolytic cell for proton exchange membrane water electrolysis, belonging to the field of membrane electrode technology. The membrane electrode comprises a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer, which are sequentially connected. The first adhesive layer comprises styrene-butadiene rubber and an anode catalyst; the second adhesive layer comprises a perfluorosulfonic acid resin and an anode catalyst; and the third adhesive layer comprises a perfluorosulfonic acid resin and a cathode catalyst. The membrane electrode exhibits high catalytic activity and good stability. The preparation method is simple and suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of membrane electrodes, and in particular to a membrane electrode and a preparation method thereof, and an electrolytic cell for proton exchange membrane water electrolysis. Background Art

[0002] Among numerous renewable energy sources, hydrogen energy has attracted considerable attention due to its green, environmentally friendly, and efficient nature. As a key technology for producing hydrogen, proton exchange membrane water electrolysis (PEMWE) has gradually become a focus of attention.

[0003] Proton exchange membrane electrolysis (PEM) water electrolysis technology often uses a binder to bond the electrodes and maintain the structural integrity of the electrode active material. Currently, the mainstream PEM water electrolysis technology uses perfluorosulfonic acid resin (Nafion). In addition to bonding the electrode components, this binder can also enhance the proton conductivity of the membrane electrode and reduce its internal resistance. However, the sulfonate groups contained in Nafion react with the Ir-based material at the membrane electrode operating point, poisoning the electrode material and reducing the number of active sites, which seriously affects the material's performance and stability. Therefore, how to reduce the toxicity of Nafion to the electrode material has become a challenging issue.

[0004] On the other hand, other binders exhibit significantly poorer internal resistance than Nafion. When using binders such as styrene-butadiene rubber (SBR), the high-frequency impedance of the battery is approximately 25% higher than that of batteries made with pure Nafion. This is because polymers such as SBR form an ionomer film on the surface of the proton exchange membrane, hindering the proton exchange process and thus affecting the battery's internal resistance, which in turn reduces battery performance.

[0005] In summary, it is of great significance to research and develop a membrane electrode with a structure of multiple binders to overcome the above-mentioned problems such as poisoning and performance degradation. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a membrane electrode and a preparation method thereof, and an electrolytic cell for proton exchange membrane water electrolysis. The membrane electrode has high catalytic activity and excellent stability.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a membrane electrode, comprising a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer connected in sequence;

[0009] The first bonding layer includes styrene-butadiene rubber (SBR) and an anode catalyst;

[0010] The second bonding layer includes perfluorosulfonic acid resin (Nafion) and anode catalyst;

[0011] The third bonding layer includes perfluorosulfonic acid resin and cathode catalyst.

[0012] The membrane electrode of the present invention reduces the poisoning of the anode catalyst by the perfluorosulfonic acid resin, and also avoids the blockage of the proton transmission channel between the proton exchange membrane and the above-mentioned adhesive layer.

[0013] Preferably, the anode catalyst is selected from an iridium-based catalyst, an iridium-based supported catalyst or a ruthenium-based catalyst;

[0014] The iridium-based catalyst includes but is not limited to iridium oxide and the like.

[0015] The iridium-based supported catalyst includes but is not limited to niobium oxide-supported iridium or titanium oxide-supported iridium.

[0016] The ruthenium-based catalyst includes but is not limited to ruthenium oxide or iridium-ruthenium alloy.

[0017] In some specific embodiments of the present invention, iridium oxide is preferred.

[0018] Preferably, the cathode catalyst is selected from 20% Pt / C, 40% Pt / C or 60% Pt / C; more preferably, 60% Pt / C.

[0019] The 60% Pt / C means that the Pt / C catalyst contains 60% Pt.

[0020] Preferably, the total loading amount of the anode catalyst in the first adhesive layer and the second adhesive layer in the membrane electrode is 0.5-2 mg / cm 2 In some specific embodiments of the present invention, 1 mg / cm 2 .

[0021] More preferably, the loading amount of the anode catalyst in the perfluorosulfonic acid resin in the first bonding layer is 0.3-0.7 mg / cm 2 ; More preferably 0.3 mg / cm 2 , 0.5 mg / cm 2 or 0.7 mg / cm 2 .

[0022] More preferably, the loading amount of the anode catalyst in the styrene-butadiene rubber in the second adhesive layer is 0.3-0.7 mg / cm 2 ; More preferably 0.3 mg / cm 2 , 0.5 mg / cm 2 or 0.7 mg / cm 2 .

[0023] In some specific embodiments of the present invention, preferably, the loading amount of the anode catalyst in the first adhesive layer in the perfluorosulfonic acid resin is 0.3 mg / cm 2 , and the loading amount of the anode catalyst in the second adhesive layer in the styrene-butadiene rubber is 0.7 mg / cm 2 ; The membrane electrode is represented by 0.3Nafion+0.7SBR membrane electrode;

[0024] Alternatively, the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.5 mg / cm 2 , and the loading amount of the anode catalyst in the second adhesive layer in the styrene-butadiene rubber is 0.5 mg / cm 2 ; The membrane electrode is represented by 0.5Nafion+0.5SBR membrane electrode;

[0025] Alternatively, the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.7 mg / cm 2 , and the loading amount of the anode catalyst in the second adhesive layer in the styrene-butadiene rubber is 0.3 mg / cm 2 ; The membrane electrode is represented by 0.7Nafion+0.3SBR membrane electrode;

[0026] In the above representation of membrane electrode, the coefficients before Nafion and SBR represent the loading amount of the anode catalyst respectively.

[0027] Preferably, the Pt loading in the cathode catalyst is 0.2-0.6 mg / cm 2 More preferably, 0.3 to 0.5 mg / cm 2 In some specific embodiments of the present invention, preferably 0.4 mg / cm 2 .

[0028] On the one hand, the membrane electrode can reduce the content of Nafion on the membrane electrode surface, effectively inhibiting its poisoning effect on the membrane electrode, thereby increasing the electrochemical active area of the membrane electrode and improving the catalytic activity and stability of the membrane electrode; on the other hand, it ensures that the proton transmission channel is not blocked, improves the proton conduction capacity of the membrane electrode, thereby reducing the impedance of the membrane electrode and improving the catalytic activity of the membrane electrode.

[0029] Preferably, the mass ratio of the perfluorosulfonic acid resin to the anode catalyst in the second adhesive layer is 1:(5-20); in some specific embodiments of the present invention, it is preferably 1:7.5.

[0030] Preferably, the mass ratio of styrene-butadiene rubber to anode catalyst in the first adhesive layer is 1:(5-20); in some specific embodiments of the present invention, it is preferably 1:19.

[0031] Preferably, the mass ratio of the perfluorosulfonic acid resin to the cathode catalyst in the third adhesive layer is 1:(3-15). In some specific embodiments of the present invention, it is preferably 1:4.

[0032] The present invention also provides a method for preparing the above-mentioned membrane electrode, comprising the following steps:

[0033] sequentially coating the first slurry and the second slurry on the surface of the proton exchange membrane, coating the third slurry on the other side of the proton exchange membrane, and drying to obtain the membrane electrode;

[0034] Wherein, the first slurry is obtained by mixing an anode catalyst, a solvent, and a perfluorosulfonic acid resin;

[0035] The second slurry is obtained by mixing an anode catalyst, a solvent, and styrene-butadiene rubber;

[0036] The third slurry is obtained by mixing a cathode catalyst, a solvent, and a perfluorosulfonic acid resin.

[0037] Preferably, the solvent is selected from one or more of water, isopropanol, ethanol, and butanol; more preferably, it is a mixed solvent of water and isopropanol, or a mixed solvent of water, isopropanol, and ethanol.

[0038] Preferably, in the present invention, the mass ratio of the first slurry to the second slurry is (3-7): (3-7); more preferably 1:1.

[0039] The present invention has no particular limitation on the mixing method for obtaining the first slurry, the second slurry, and the third slurry, and any method well known to those skilled in the art may be used.

[0040] In some specific embodiments of the present invention, ball milling and ultrasonic dispersion are used.

[0041] The ball milling speed is 200-400 rpm, more preferably 300 rpm.

[0042] The ball milling mixing time is 12 to 24 hours, more preferably 18 hours.

[0043] The ultrasonic dispersion time is 0.5 to 1.5 h, more preferably 1 h.

[0044] In the present invention, the drying temperature is preferably 60°C to 100°C, more preferably 70°C to 90°C, and in some specific embodiments of the present invention, preferably 80°C.

[0045] Preferably, the drying adsorption pressure is 0.2-0.4 MPa; more preferably 0.25-0.35 MPa; further preferably 0.3 MPa.

[0046] Preferably, the method for preparing the membrane electrode of the present invention comprises the following steps:

[0047] S1, mixing the electrolytic water anode catalyst and a mixed solvent of water and isopropyl alcohol to obtain a first suspension;

[0048] S2, mixing the electrolytic water cathode catalyst and a mixed solvent of water and isopropyl alcohol to obtain a second suspension;

[0049] S3, dividing the first suspension into two parts, adding Nafion dispersion and styrene-butadiene rubber dispersion respectively thereto, and performing ball milling and ultrasonic dispersion to obtain a first slurry and a second slurry respectively;

[0050] S4, mixing the second suspension and Nafion dispersion, ball milling, and ultrasonic dispersion to obtain a third slurry;

[0051] S5, coating the first slurry and the second slurry on a proton exchange membrane in sequence, and drying to obtain an anode membrane electrode having a structure of multiple binders;

[0052] S6. Coating the third slurry on the other side of the proton exchange membrane and drying it to obtain a membrane electrode structured with multiple binders.

[0053] There is no order between the above steps S1 and S2, there is no order between S3 and S4, and there is no order between S5 and S6.

[0054] The mass ratio of the anode catalyst, water and isopropanol in the first suspension is (1-16): (250-1000): (250-1000).

[0055] Preferably, the mass ratio of the anode catalyst to water and isopropanol in the second suspension is (1-16): (250-1000): (250-1000).

[0056] The preparation method of the present invention disperses the anode catalyst and the cathode catalyst respectively in a mixed solvent of water and isopropyl alcohol, then mixes the adhesive Nafion and styrene-butadiene rubber with the dispersed anode catalyst respectively to obtain a first slurry and a second slurry, and mixes the adhesive Nafion with the dispersed cathode catalyst to obtain a third slurry.

[0057] Then, the first slurry and the second slurry are sequentially layered and coated on the anode side of the membrane electrode, and the third slurry is coated on the cathode side of the membrane electrode, and finally a membrane electrode with multiple binders structured is obtained.

[0058] The preparation method is simple to operate, has little environmental pollution, and is suitable for large-scale industrial production.

[0059] The present invention also provides an electrolytic cell for proton exchange membrane water electrolysis, comprising the above-mentioned membrane electrode or the membrane electrode prepared by the above-mentioned preparation method.

[0060] The electrolytic cell has high catalytic activity and good stability when used for proton exchange membrane water electrolysis.

[0061] Compared to the prior art, the membrane electrode provided by the present invention comprises a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer, which are sequentially connected. The first adhesive layer comprises styrene-butadiene rubber and an anode catalyst; the second adhesive layer comprises a perfluorosulfonic acid resin and an anode catalyst; and the third adhesive layer comprises a perfluorosulfonic acid resin and a cathode catalyst. The membrane electrode exhibits high catalytic activity and good stability. The preparation method of the membrane electrode is simple and suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Flowchart for preparing structured membrane electrodes with various binders according to Example 1;

[0063] Figure 2 This is a comparison chart of the battery performance of the structured membrane electrode with various binders prepared in Example 1, the membrane electrode with conventional pure Nafion as a binder (Nafion electrode), and the membrane electrode with conventional pure SBR as a binder (SBR electrode);

[0064] Figure 3 This is a comparison of the steady-state polarization curves of the structured membrane electrode with various binders prepared in Example 1 and the membrane electrode with conventional pure Nafion as a binder before and after a 100-h accelerated aging test;

[0065] Figure 4 A comparison of steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 2 and the membrane electrode with conventional pure Nafion as a binder;

[0066] Figure 5 A comparison of steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 3 and the membrane electrode with conventional pure Nafion as a binder;

[0067] Figure 6 A comparison of steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 4 and the membrane electrode with conventional pure Nafion as a binder;

[0068] Figure 7 This is a comparison of the steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 5 and the membrane electrode with conventional pure Nafion as the binder. DETAILED DESCRIPTION

[0069] To further illustrate the present invention, the membrane electrode and its preparation method, and the electrolytic cell for proton exchange membrane water electrolysis provided by the present invention are described in detail below with reference to the embodiments.

[0070] Example 1

[0071] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 160 mg of commercial 60% Pt / C was added to a mixed solution of 20 mL of water and 20 mL of isopropanol to obtain a second suspension;

[0072] Step S2: The first suspension prepared in step S1 was divided into two equal parts, 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) was added to the first part, and 632 μL of SBR (styrene-butadiene rubber) aqueous solution (10 mg / mL, 6.32 mg of SBR) was added to the second part, and the mixture was ball-milled and ultrasonically dispersed to obtain a first and a second slurry, respectively. The second suspension prepared in step S1 was taken, and 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) was added thereto, and the mixture was ball-milled and ultrasonically dispersed to obtain a third slurry;

[0073] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying conditions are 80° C. and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with multiple binder structures is obtained, which is represented by 0.5Nafion+0.5SBR membrane electrode.

[0074] The membrane electrode with various binder structures prepared in Example 1, the membrane electrode with conventional pure Nafion as a binder (i.e., Nafion electrode), and the membrane electrode with conventional pure SBR as a binder (i.e., SBR electrode) were assembled into water electrolysis cells. The steady-state polarization curves of the electrodes are shown in FIG. Figure 2 The results show that compared with Nafion electrode and SBR electrode, the 0.5Nafion+0.5SBR membrane electrode prepared in Example 1 has better activity at 3A / cm 2 At high current density, the performance is improved by 43 mV compared with Nafion electrode and 135 mV compared with SBR electrode.

[0075] Figure 3 These are the steady-state polarization curves of the membrane electrode with multiple binder structures (0.5Nafion+0.5SBR membrane electrode) in Example 1 of the present invention and the membrane electrode with conventional pure Nafion as a binder (Nafion electrode) before and after a 100-h accelerated aging experiment. The results show that after a 100-h accelerated aging experiment, the performance of the membrane electrode with conventional pure Nafion as a binder (Nafion electrode) decreased by 15mV, while the performance of the membrane electrode with multiple binder structures (0.5Nafion+0.5SBR membrane electrode) prepared in Example 1 decreased by 7mV, indicating that the membrane electrode with multiple binder structures prepared by the present invention has better stability.

[0076] Example 2

[0077] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 10 mL of isopropanol to obtain a second suspension;

[0078] Step S2: The first suspension prepared in step S1 was divided into 18 mL and 42 mL, 203 μL of 5% Nafion-ethanol dispersion (9.45 mg of Nafion) was added to the first portion, and 884 μL of SBR aqueous solution (10 mg / mL, 8.84 mg of SBR) was added to the second portion, and ball milling and ultrasonic dispersion were performed to obtain the first and second slurries. The second suspension prepared in step S1 was taken, 413 μL of 5% Nafion-ethanol dispersion (19.2 mg of Nafion) was added thereto, and ball milling and ultrasonic dispersion were performed to obtain the third slurry;

[0079] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and 0.3 mg / cm 2 catalyst (iridium oxide) and 0.7 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying conditions are 80° C. and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with multiple binder structures is obtained, which is represented by 0.3Nafion+0.7SBR membrane electrode.

[0080] Different from Example 1, in Example 2, the iridium oxide loading in the Nafion layer is reduced, and the iridium oxide loading in the SBR layer is increased.

[0081] Example 3

[0082] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 10 mL of isopropanol to obtain a second suspension;

[0083] Step S2: The first suspension prepared in step S1 was divided into 24 mL and 18 mL, 474 μL of 5% Nafion-ethanol dispersion (22.06 mg Nafion) was added to the first portion, and 379 μL of SBR aqueous solution (10 mg / mL, 3.79 mg of SBR) was added to the second portion, and ball milling and ultrasonic dispersion were performed to obtain the first and second slurries. The second suspension prepared in step S1 was taken, 413 μL of 5% Nafion-ethanol dispersion (19.2 mg Nafion) was added thereto, and ball milling and ultrasonic dispersion were performed to obtain the third slurry;

[0084] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and 0.7 mg / cm 2 catalyst (iridium oxide) and 0.3 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying conditions are 80° C. and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with multiple binder structures is obtained, which is represented by 0.7Nafion+0.3SBR membrane electrode.

[0085] Different from Example 1, in Example 3, the iridium oxide loading amount of the Nafion layer is increased, and the iridium oxide loading amount of the SBR layer is reduced.

[0086] Example 4

[0087] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 15 mL of water and 45 mL of isopropanol to obtain a first suspension, and 160 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 30 mL of isopropanol to obtain a second suspension;

[0088] Step S2: The first suspension prepared in step S1 was divided into two equal parts, 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) was added to the first part, and 632 μL of SBR aqueous solution (10 mg / mL, 6.32 mg of SBR) was added to the second part, and the mixture was ball-milled and ultrasonically dispersed to obtain the first and second slurries. The second suspension prepared in step S1 was taken, 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) was added thereto, and the mixture was ball-milled and ultrasonically dispersed to obtain the third slurry;

[0089] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying conditions are 80° C. and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with multiple binder structures is obtained, which is represented by 0.5Nafion+0.5SBR membrane electrode.

[0090] Different from Example 1, Example 4 changes the ratio of water to isopropyl alcohol in the slurry.

[0091] Example 5

[0092] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 15 mL of water and 15 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 5 mL of water and 5 mL of isopropanol to obtain a second suspension;

[0093] Step S2: The first suspension prepared in step S1 was divided into two equal parts, 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) was added to the first part, and 632 μL of SBR aqueous solution (10 mg / mL, 6.32 mg of SBR) was added to the second part, and the mixture was ball-milled and ultrasonically dispersed to obtain the first and second slurries. The second suspension prepared in step S1 was taken, 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) was added thereto, and the mixture was ball-milled and ultrasonically dispersed to obtain the third slurry;

[0094] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying conditions are 80° C. and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with multiple binder structures is obtained, which is represented by 0.5Nafion+0.5SBR membrane electrode.

[0095] Different from Example 1, the concentration of the slurry was changed in Example 5.

[0096] The membrane electrodes with various binder structures prepared in Examples 2 to 5 were assembled into water electrolysis cells, and their steady-state polarization curves were as follows: Figures 4 to 7 shown.

[0097] Figures 4 to 7 The steady-state polarization curves of the membrane electrodes with various structures of binders prepared in Examples 2 to 5 of the present invention are compared with those of the conventional membrane electrodes with pure Nafion as a binder. Figures 4 to 7 As shown in the figure, under the conditions of different anode catalyst loadings of Nafion layer and SBR layer and different water-alcohol ratios defined in the present invention, membrane electrodes with various binder structures having good catalytic activity and stability can be synthesized, which have a high catalytic activity at 3A / cm 2 The potential required for aging is 30-50 mV lower than that of the membrane electrode with conventional pure Nafion as a binder, and the performance degradation after accelerated aging is 45% of that of the membrane electrode with conventional pure Nafion as a binder, that is, the membrane electrode described in the present invention has higher electrochemical activity and better stability.

[0098] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A membrane electrode, characterized in that It includes a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer connected in sequence; Wherein, the first bonding layer comprises styrene-butadiene rubber and an anode catalyst; The second bonding layer includes perfluorosulfonic acid resin and anode catalyst; The third bonding layer includes perfluorosulfonic acid resin and cathode catalyst; The mass ratio of styrene-butadiene rubber to anode catalyst in the first bonding layer is 1:(5-20); The mass ratio of the perfluorosulfonic acid resin to the anode catalyst in the second adhesive layer is 1:(5-20); The loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.3-0.7 mg / cm 2 ; The loading amount of the anode catalyst in the styrene-butadiene rubber in the second bonding layer is 0.3-0.7 mg / cm 2 .

2. The membrane electrode according to claim 1, characterized in that The anode catalyst is selected from iridium oxide-based catalysts, iridium-based supported catalysts or ruthenium-based catalysts; The cathode catalyst is selected from 20% Pt / C, 40% Pt / C or 60% Pt / C.

3. The membrane electrode according to claim 1 or 2, characterized in that The total loading amount of the anode catalyst in the first adhesive layer and the second adhesive layer in the membrane electrode is 0.5-2 mg / cm 2 .

4. The membrane electrode according to claim 1 or 2, characterized in that The Pt loading in the cathode catalyst is 0.2-0.6 mg / cm 2 .

5. The membrane electrode according to claim 1 or 2, characterized in that: The mass ratio of the perfluorosulfonic acid resin to the cathode catalyst in the third adhesive layer is 1:(3-15).

6. The method for preparing a membrane electrode according to any one of claims 1 to 5, characterized in that: The following steps are involved: sequentially coating the first slurry and the second slurry on the surface of the proton exchange membrane, coating the third slurry on the other side of the proton exchange membrane, and drying to obtain the membrane electrode; Wherein, the first slurry is obtained by mixing an anode catalyst, a solvent, and a perfluorosulfonic acid resin; The second slurry is obtained by mixing an anode catalyst, a solvent, and styrene-butadiene rubber; The third slurry is obtained by mixing a cathode catalyst, a solvent, and a perfluorosulfonic acid resin.

7. The preparation method according to claim 6, characterized in that The solvent is selected from one or more of water, isopropanol, ethanol and butanol.

8. The preparation method according to claim 6, characterized in that The mass ratio of the first slurry to the second slurry is (3-7): (3-7).

9. The preparation method according to claim 6, characterized in that The drying temperature is 60°C to 100°C; The drying adsorption pressure is 0.2-0.4 MPa.

10. An electrolytic cell for proton exchange membrane water electrolysis, characterized in that: The invention comprises the membrane electrode according to any one of claims 1 to 5 or the membrane electrode prepared by the preparation method according to any one of claims 6 to 9.

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