CN114196967A

CN114196967A - Method for preparing membrane electrode for water electrolysis of high mass transfer PEM (proton exchange membrane)

Info

Publication number: CN114196967A
Application number: CN202111473165.7A
Authority: CN
Inventors: 郝金凯; 张洪杰; 邵志刚
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2022-03-18
Anticipated expiration: 2041-12-03
Also published as: CN114196967B

Abstract

The invention discloses a preparation method of a PEM water electrolysis membrane electrode, which adopts multi-nozzle type spraying equipment to independently spray different components of multi-component composite slurry of a catalyst layer in an ultra-short time, accurately control the spraying speed and the atomization degree of the different components and solve the problem of poor dispersibility of different catalysts and binders in the catalyst slurry in the same solution; the multi-component composite slurry comprises catalysts with different components, high-conductivity short-side-chain perfluorosulfonic acid resin, high-chemical-stability nano additive and the like, and the membrane electrode prepared by the method can effectively improve the proton transmission rate of a water electrolysis membrane electrode and reduce the electrolysis voltage, thereby reducing the cost of PEM (proton exchange membrane) electrolyzed water and prolonging the service life; the membrane electrode provided by the invention can be applied to devices such as a PEM water electrolyzer, a PEM water electrolysis hydrogen production system and the like to be used as a proton exchange membrane electrode.

Description

Method for preparing membrane electrode for water electrolysis of high mass transfer PEM (proton exchange membrane)

Technical Field

The invention relates to the technical field of water electrolysis of proton exchange membranes, in particular to a preparation method of a high mass transfer PEM water electrolysis membrane electrode.

Background

Hydrogen is considered as the most ideal energy carrier because of its advantages of cleanness, no pollution, high efficiency, storage and transportation, etc. The hydrogen production by water electrolysis is the simplest method for obtaining pure hydrogen at present, and if the hydrogen production is combined with renewable resource power generation technologies, such as photovoltaic power generation, hydroelectric power generation and wind power generation, the water electrolysis can be used as a large-scale hydrogen production technology, and has the advantages of small environmental pollution, less greenhouse gas emission, good economy and good application prospect. The electrolysis cell is used as a core component of an electrolysis water system, and the investment and production cost of the electrolysis cell determine the economical efficiency and the technical advancement of the system. According to the different properties of electrolytes, the hydrogen production technology by water electrolysis mainly has three types: a water electrolyzer using alkali liquor and Proton Exchange Membrane (PEM) as electrolyte and a solid oxide water electrolyzer. The alkaline electrolytic cell using alkali liquor as electrolyte is the water electrolysis hydrogen production technology with the longest history and the mature technology, but the alkaline electrolytic cell has lower efficiency and lower working current density which is generally not higher than 0.6A/cm²(ii) a The solid oxide water electrolytic cell generally adopts yttria-stabilized zirconia as electrolyte, the working temperature is 600-1000 ℃, the high temperature reduces the voltage loss of the electrolytic reaction, simultaneously increases the corrosion speed of the electrolytic cell, increases the cold-hot expansion amount, brings difficulties to the selection, sealing and operation control of materials, and restricts the application of the solid oxide water electrolytic cell; the water electrolyzer with PEM as electrolyte can be 1-3A/cm²The hydrogen production device works under high current density, has small volume and high efficiency, and the purity of the generated hydrogen can reach 99.999 percent, so the hydrogen production device is considered to be the most promising hydrogen production technology by electrolyzing water.

The membrane electrode is a place where the water electrolysis reaction of the proton exchange membrane occurs, and the proton exchange membrane has high ionic conductivity and also has electrochemical stability which is a factor which needs to be considered. Since the stability of the PEM directly determines the long-term operating life of fuel cells and SPE water electrolysis cells, the PEM degradation was studiedThe degradation mainly comprises mechanical degradation, thermal degradation and chemical degradation, wherein the chemical degradation is the main degradation mode of the proton exchange membrane in long-term operation. For chemical degradation of the PEM, during fuel cell operation, many factors such as permeation of reactant gases, dissolution and redeposition of catalyst platinum, transition metal ion impurities and free radical generation can cause chemical degradation of the membrane; under the condition of water electrolysis, H is often accompanied₂O₂When the transition metal ion is reacted with H₂O₂In coexistence, H₂O₂Easy decomposition of HO&HOO, etc., attack the proton exchange membrane. It is currently generally accepted that chemical degradation is mainly free radicals (HO.)&HOO.) attacks the main chain or side chains of the polymer film. Therefore, it is an important subject to improve the chemical stability of the proton exchange membrane.

In addition, in the preparation process of the water electrolysis membrane electrode, the CCM is prepared by adopting a spraying mode, the requirement on the dispersion of the catalyst slurry on the anode and the cathode side is higher, and particularly, the catalyst slurry needs to be added with a binder, so that the dispersion difficulty of the catalyst slurry is increased, and the uniformity of a sprayed catalyst layer is poor; on the other hand, an important role of the binder in the catalyst layer is to conduct protons, and how to increase the proton conducting function is a problem that needs to be continuously solved at present.

Disclosure of Invention

The invention aims to provide a preparation method of a high mass transfer PEM water electrolysis membrane electrode, which solves the problems of chemical degradation of a proton exchange membrane by peroxide radicals and proton conduction of a catalyst layer in the running process of PEM water electrolysis.

The technical purpose of the invention is realized by the following technical scheme:

a preparation method of a PEM water electrolysis membrane electrode comprises the following steps:

(1) preparing slurry: the slurry comprises catalyst slurry I, catalyst slurry II, binder slurry and functional nano particle slurry; the solute of the binder slurry is short-side-chain perfluorosulfonic acid resin, and the side-chain molecular structure of the short-side-chain perfluorosulfonic acid resin is-OCF₂CF₂SO₃H、-OCF₂CF₂CF₂SO₃H、-OCF₂SO₃H; the functional nano particles are one or more of nano-scale phosphorylated cerium dioxide, sulfonated manganese dioxide, nano-cerium dioxide and nano-manganese dioxide;

(2) respectively injecting the catalyst slurry I, the binder slurry and the functional nanoparticle slurry into each spray head of multi-spray-head type spraying equipment, simultaneously performing linear spraying on the front surface of the proton exchange membrane by a plurality of spray heads injected with the slurry, and completely drying to finish spraying and feeding on the front surface of the perfluorosulfonic acid membrane;

(3) respectively injecting the catalyst slurry II, the binder slurry and the functional nanoparticle slurry into each spray head of multi-spray-head type spraying equipment, simultaneously performing linear spraying on the back of the perfluorosulfonic acid membrane by a plurality of spray heads injected with the slurry, and completely drying to obtain CCM;

and hot-pressing and molding the CCM, the carbon paper and the plastic frame to prepare the PEM water electrolysis membrane electrode, wherein the hot-pressing temperature is 70-150 ℃.

The invention is further configured to: in the step (1), the catalyst slurry I is prepared in the following manner: adding the catalyst I into an alcohol solvent, and performing ultrasonic stirring at room temperature to obtain catalyst slurry I; the catalyst slurry II is prepared in the following way: adding the catalyst II into an alcohol solvent, and performing ultrasonic stirring at room temperature to obtain catalyst slurry II; in the catalyst slurry I and the catalyst slurry II, the alcohol solvent is one or more of ethanol, normal propyl alcohol, isopropanol, methanol and normal butanol respectively and independently, and the ultrasonic stirring time at room temperature is 1-10 hours.

The invention is further configured to: in the step (1), the catalyst in the catalyst slurry I is a platinum-based catalyst, the platinum-based catalyst comprises one or a mixture of two of Pt/C, Pt black, Pt nano powder and the like, the catalyst in the catalyst slurry II is an iridium-based catalyst, and the iridium-based catalyst comprises one or a mixture of two of iridium/C, iridium black and iridium nano powder; the solid content in the catalyst slurry I and the solid content in the catalyst slurry II are both 0.1-5 wt.%, and the catalyst loading is both 10-100 wt.%.

The invention is further configured to: : in the step (1), the binder slurry is prepared in the following manner: adding a short side chain perfluorosulfonic acid resin solution into a solvent for dilution and dispersion, and performing ultrasonic stirring at room temperature to obtain a binder slurry; the concentration of the binder slurry is 0.5-15 wt%, the solution solvent is deionized water or alcohol-water mixture, the mass concentration of the used short-side-chain perfluorosulfonic acid resin solution is 20%, wherein the short-side-chain perfluorosulfonic acid resin exists in the form of nano-dispersed particles, and the particle size of the nano-dispersed particles is 20-200 nm.

The invention is further configured to: the functional nano particle slurry is prepared in the following manner; and adding the functional nanoparticles into a solvent for dispersion, and performing ultrasonic stirring at room temperature to obtain functional nanoparticle slurry, wherein the particle size of the functional nanoparticles is 1-10nm, the concentration of the functional nanoparticles is 0.1-3 wt.%, and the solvent is one or more of ionized water, ethanol, isopropanol and n-butanol.

The invention is further configured to: the load of each component of CCM is respectively as follows: platinum-based catalyst 0.3-1.2mg/cm²0.5-1.5mg/cm of iridium-based catalyst²Short side chain perfluorosulfonic acid resin 0.2-0.8mg/cm²0.05-0.3mg/cm of functional nano-particles²。

The invention is further configured to: in the steps (2) and (3), the proton exchange membrane is always in a heated state during spraying any slurry; the heating temperature of the proton exchange membrane is 50-100 ℃, the proton exchange membrane is heated by an adsorption heating table, and the vacuum degree of the adsorption heating table is-0.04 to-0.2 MPa; the spraying modes of the spray heads are linear spraying, the spraying gap is 0.5-5cm, the spraying speed is 100-400mm/s, and the ultrasonic frequency of the machine spray head is 48-80 Hz;

in the step (2), the spraying flow rates are respectively as follows: the catalyst slurry 1 is 0.5-20mL/min, the binder slurry 3 is 1-10mL/min, and the functional nanoparticle slurry 4 is 0.2-5 mL/min; the spraying times are repeated for 1-10 times.

In the step (3), the spraying flow rate of each slurry is respectively as follows: catalyst slurry II is 0.5-15mL/min, binder slurry is 1-10mL/min, and functional nanoparticle slurry is 0.2-5 mL/min; the spraying times are repeated for 1-10 times.

The invention is further configured to: the proton exchange membrane is a perfluorosulfonic acid membrane; the perfluorosulfonic acid membrane is one of Nafion115, 117, 211, 212 and a perfluorosulfonic acid composite membrane.

The invention is further configured to: in the step (2) and the step (3), the spraying equipment comprises two groups of spray head groups, the number of the spray heads in each group of spray head groups is not less than 3, the distance between every two spray heads in each group of spray head groups is 0.5-5cm, and the spray heads in each group of spray head groups are arranged in a transverse array or a longitudinal array.

The invention is further configured to: in step (2) and step (3), the shower nozzle all is including being cylindric nozzle body, circumference array is equipped with the thick liquids direction recess of a plurality of semicircle forms on the outer circumferential wall of nozzle body, the bottom of nozzle body is all run through to the thick liquids direction recess, all be equipped with the notes material pipe that supplies thick liquids to pour into in the thick liquids direction recess, this internal coaxial air outlet channel that can be used for a plurality of thick liquids direction recess departments simultaneously that is equipped with of nozzle, air outlet channel appears when being used for avoiding thick liquids to flow from each thick liquids direction recess department and bias current.

In conclusion, the invention has the following beneficial effects:

1. according to the invention, a spraying mode of combining a plurality of spray heads is adopted, slurries with different components are dispersed independently and are sprayed simultaneously after ultrasonic atomization, so that the reduction of active sites of catalyst particles and the reduction of catalyst performance caused by the reduction of active sites of the catalyst particles after the catalyst particles and a high-molecular binder are mixed for a long time are avoided; on the other hand, the problems of catalyst particle agglomeration, uneven prepared catalyst layer and the like caused by difficult dispersion after mixing of the binder and the catalyst are avoided;

in the preparation method, the slurry with different components is dispersed independently, so that the situation that the catalyst and the binder are mixed together and then the binder is wound on the surfaces of catalyst particles to shield active sites of the catalyst and influence the catalytic performance of the catalyst is avoided; on the other hand, the catalyst layer structure and the functional layer structure formed by batch spraying are beneficial to the transfer of protons and oxygen, so that the catalytic performance of the catalyst is enhanced, and the catalytic efficiency is improved.

2. The selected binder is short-side-chain perfluorosulfonic acid resin, and has higher ion exchange capacity, so that the proton conductivity of the binder is better, and compared with long-side-chain perfluorosulfonic acid resin, the short-side-chain perfluorosulfonic acid resin has better chemical stability because a tertiary carbon and an ether bond are reduced in the side chain and the side chain is free from the attack of free radicals, so that the proton conductivity of a catalyst layer is not reduced due to degradation loss along with operation; in addition, the short-side-chain perfluorosulfonic acid resin is used as a binder, and due to the short-side-chain structure of the resin, functional nanoparticles cannot be completely wrapped, the free radical scavenging effect of the nanoparticles cannot be influenced, and the proton conduction performance of the catalyst layer can be improved.

3. Functional nano particles are added into the spraying components of the membrane electrode slurry, and because free radicals generated at an oxygen evolution side can chemically degrade a proton exchange membrane in the process of the rerunning of a water electrolysis membrane electrode, the spraying of the functional nano particles can eliminate the free radicals on one hand and prolong the service life of the proton exchange membrane; on the other hand, the nanoparticles mainly function to eliminate free radicals at present, but the unfunctionalized nanoparticles can hinder proton conduction, and the functionalized nanoparticles are selected under the condition of not influencing proton conduction efficiency; the functional groups are mainly sulfonic acid groups and phosphoric acid groups, and the sulfonic acid groups and the phosphoric acid groups are also proton conducting groups in the proton exchange membrane, so that the proton conducting capability can be increased together with the proton exchange membrane and a binder, and the proton conducting capability and the electrochemical characteristics of the membrane electrode in the operation process are improved;

4. in the spraying process, multiple nozzles are adopted for continuous spraying for multiple times, so that the components of the catalyst layer prepared by spraying are more uniform, the performance of each component is fully exerted on one hand, the thickness of the prepared catalyst layer is more uniform, the catalyst layer cannot crack, fall off and the like, the catalytic performance and the proton conductivity are better, and the service life is longer;

5. the invention not only adopts multi-nozzle type spraying, but also each nozzle is further designed into a multi-material injection pipe type, namely, various slurries can be injected into each nozzle simultaneously, thereby realizing different spraying combinations of the multi-component slurries, adjusting according to the preparation requirements and function settings of the membrane electrode, meeting the preparation requirements of diversified membrane electrodes, simultaneously realizing the mixing of the slurries with different components from the spraying angle, and forming a more uniform and more compact electrode structure by an ultrasonic atomization mode.

6. The multiple spray heads can be arranged in a transverse array mode and a longitudinal array mode, so that the multiple spray heads can realize the multiple spray modes of the perfluorosulfonic acid membrane, are suitable for spray production of products with various models and requirements, have high production process efficiency and material utilization rate, and cannot cause waste and loss of materials.

Drawings

FIG. 1 is a schematic view of a single spray head of an electrostatic spraying apparatus used in the present invention;

FIG. 2 is a schematic view of a plurality of showerheads in a transverse array arrangement over a perfluorosulfonic acid membrane;

fig. 3 is a schematic diagram of a plurality of spray heads arranged in a longitudinal array over a perfluorosulfonic acid membrane.

In the figure: 1. an electrostatic spraying device; 2. a nozzle group; 3. a spray head; 3-1, a nozzle body; 3-2, slurry guide grooves; 3-3, a material injection pipe; 3-4, an air outlet channel; 4. adsorption type heating table.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The ultrasonic spraying equipment comprises an adsorption heating table, a driving sliding table which is arranged right above the adsorption heating table and is electrically controlled, and a spray head arranged on the driving sliding table, wherein the spray head is connected with a feeding system pipeline.

In the invention, the ultrasonic spraying equipment adopts two groups of nozzles with multiple nozzles and two driving sliding tables, the two groups of nozzles are respectively arranged on different driving sliding tables so as to improve the displacement freedom degree of each nozzle in each group of nozzles, the number of the nozzles in each group of nozzles is at least 3, and the multiple nozzles can transversely or longitudinally slide under the action of the sliding rails of the driving sliding tables so as to realize transverse array arrangement or longitudinal array during spraying work and the adjustment of the distance between every two nozzles, as shown in fig. 2 and 3 (the driving sliding tables are conventionally arranged in the mechanical field, and the sliding rails and the electrical installation and connection mode are not repeated in the invention).

As shown in fig. 1, in the present invention, each nozzle includes a cylindrical nozzle body, a plurality of semicircular slurry guiding grooves are arranged in a circumferential array on an outer circumferential wall of the nozzle body, the slurry guiding grooves all penetrate through a bottom end of the nozzle body, slurry injecting pipes for injecting slurry are arranged in the slurry guiding grooves, the slurry guiding grooves are used for realizing mutual isolation and guiding effects in a discharging stage after multiple types of slurry are injected, air outlet channels are coaxially arranged in the nozzle body, the air outlet channels arranged at an axis can simultaneously act on each slurry guiding groove, and under the action of air flow, a bias phenomenon towards the axis can not occur when the slurry flows out from the slurry guiding grooves. Unless otherwise specified, the raw materials used in the following examples and comparative examples are all commercially available conventional raw materials. In addition, the concentrations in the following examples and comparative examples are mass percent concentrations.

Example 1:

(1) preparing slurry: weighing 0.5g of Pt nano powder with 100 percent of Pt loading capacity, adding 500g of ethanol solvent, and ultrasonically stirring and dispersing for 1 hour at room temperature to obtain catalyst slurry 1 with the content of 0.1 percent;

weighing 0.5g of iridium nano powder with 100% iridium loading capacity, adding 500g of ethanol solvent, and ultrasonically stirring and dispersing at room temperature for 1h to obtain catalyst slurry 2 with the content of 0.1%;

weighing 5g of 0.5% of a compound of the formula-OCF₂CF₂SO₃Adding 50g of deionized water into the short side chain perfluorosulfonic acid resin liquid of H, and ultrasonically stirring at room temperature for 1H to obtain binder slurry 3 with the particle size of the dispersed particles being 20 nm;

weighing 2g of phosphorylation cerium dioxide with the particle size of 1nm, adding 198g of deionized water, and ultrasonically stirring at room temperature for 1h to obtain 0.1% functional nanoparticle slurry 4;

(2) laying a Nafion115 membrane on an adsorption heating table of spraying equipment at the set temperature of 50 ℃, setting the vacuum degree to be-0.04 MPa, and adsorbing and flattening the membrane;

(3) firstly, controlling two groups of spray heads to be transversely arrayed above an adsorption heating table, then respectively injecting the

slurries

1, 3 and 4 prepared in the step (1) into one group of spray heads of spraying equipment, so that the three slurries are respectively linearly sprayed out from three spray heads of the same group of spray heads, respectively injecting the three slurries into different spray heads, and then injecting the slurries into each slurry guide groove of the spray head in batches through a plurality of injection pipes; wherein the clearance between each shower nozzle is 0.5cm, and the spraying speed is 100mm/s, and the spraying flow is: spraying for 1 time, wherein the spray head corresponding to the slurry 1 is 0.5mL/min, the spray head corresponding to the slurry 3 is 1mL/min, the spray head corresponding to the slurry 4 is 0.2mL/min, and the ultrasonic frequency of each spray head is 48 Hz;

(4) respectively injecting the slurries 2, 3 and 4 prepared in the step (1) into another group of spray heads of the spraying equipment, so that the three slurries are respectively linearly sprayed out of the three spray heads of the same group of spray heads correspondingly, and are respectively injected into different spray heads, and then are injected into each slurry guide groove of the spray head in batches through a plurality of injection pipes; turning over the perfluorosulfonic acid membrane coated with the slurry 1, 3 and 4 on the front surface of the membrane (3), namely placing the front surface of the perfluorosulfonic acid membrane close to an adsorption heating table, starting to coat the slurry 2, 3 and 4 on the back surface of the membrane after vacuum adsorption, wherein the coating gap is 0.5cm (the coating gap refers to the moving distance of the nozzle after each coating), namely the moving distance between the spraying line and the spraying line of the nozzle is 0.5cm, the spraying speed is 100mm/s, and the spraying flow is as follows: spraying for 1 time with 0.5mL/min of a spray head B corresponding to the slurry 2, 1mL/min of a spray head C corresponding to the slurry 3 and 0.2mL/min of a spray head D corresponding to the slurry 4 at the ultrasonic frequency of 48Hz to obtain a membrane electrode CCM, wherein the load of the slurry 1 is 0.3mg/cm²The supporting amount of the slurry 2 is 0.5mg/cm²The 3 supporting amount of the sizing agent is 0.2mg/cm²The 4-load of the sizing agent is 0.05mg/cm²；

(5) And (4) hot-pressing the membrane electrode CCM prepared in the step (3), the carbon paper and the plastic frame at 70 ℃ to prepare the PEM water electrolysis membrane electrode.

Example 2:

(1) preparing slurry:

weighing 5g of Pt/C catalyst powder with 10% Pt loading capacity, adding 95g of isopropanol solvent, and ultrasonically stirring and dispersing at room temperature for 24 hours to obtain 5% catalyst slurry 1;

weighing 5g of iridium/C powder with the iridium loading of 10%, adding 95g of isopropanol solvent, and ultrasonically stirring and dispersing at room temperature for 24 hours to obtain catalyst slurry 2 with the content of 5%;

weighing 5g of 15% of the compound with a structure of-OCF₂SO₃Adding 50g of deionized water into the short side chain perfluorosulfonic acid resin liquid of H, and ultrasonically stirring at room temperature for 24H to obtain adhesive slurry 3 with the particle size of resin dispersed particles being 200 nm;

weighing 6g of sulfonated manganese dioxide with the particle size of 10nm, adding into 194g of ethanol, and ultrasonically stirring at room temperature for 24h to obtain functional nanoparticle slurry 4 with the concentration of 3%;

(2) laying a Nafion117 membrane on an adsorption heating table of spraying equipment at the set temperature of 100 ℃, setting the vacuum degree to be-0.2 MPa, and adsorbing and flattening the membrane;

(3) firstly, controlling two groups of spray heads to be longitudinally arrayed above an adsorption heating table, then respectively injecting the

slurries

1, 3 and 4 prepared in the step (1) into one group of spray heads of spraying equipment, so that the three slurries are respectively linearly sprayed out from three spray heads of the same group of spray heads, and respectively injecting the three slurries into different spray heads and then injecting the slurries into each slurry guide groove of the spray head in batches through a plurality of injection pipes; wherein the clearance between each shower nozzle is 5cm, and the spraying speed 400mm/s, the spraying flow is: spraying for 10 times, wherein the spray head corresponding to the slurry 1 is 20mL/min, the spray head corresponding to the slurry 3 is 10mL/min, the spray head corresponding to the slurry is 5mL/min, and the ultrasonic frequency of each spray head is 80 Hz;

(4) respectively injecting the slurries 2, 3 and 4 prepared in the step (1) into another group of spray heads of the spraying equipment, so that the three slurries are respectively linearly sprayed out of the three spray heads of the same group of spray heads correspondingly, and the three slurries are respectively injected into different spray heads and then are injected into each slurry guide groove of the spray head in batches through a plurality of injection pipes; placing the perfluorosulfonic acid membrane with the front surface coated with the slurry 1, 3 and 4 in the step (3) in a manner of clinging to an adsorption heating table, starting to coat the slurry 2, 3 and 4 on the back surface of the membrane after vacuum adsorption, wherein the spraying gap is 5cm, the spraying speed is 400mm/s, and the spraying flow is as follows: spray head of 15mL/min corresponding to slurry 2, spray head of 10mL/min corresponding to slurry 3,Spraying 10 times with 5mL/min of spray head corresponding to slurry 4 and 80Hz of ultrasonic frequency to obtain membrane electrode CCM, wherein the load of slurry 1 is 1.2mg/cm²The supporting amount of the slurry 2 is 1.5mg/cm²The 3 supporting amount of the sizing agent is 0.8mg/cm²The 4-load of the sizing agent is 0.3mg/cm²；

(5) And (4) hot-pressing the membrane electrode CCM prepared in the step (3), the carbon paper and the plastic frame at 150 ℃ to prepare the PEM water electrolysis membrane electrode.

Example 3:

(1) preparing slurry:

weighing 2g of Pt/C catalyst powder with 50% Pt loading capacity, adding 98g of n-propanol solvent, and ultrasonically stirring and dispersing for 12 hours at room temperature to obtain catalyst slurry 1 with the content of 2%;

weighing 2g of iridium/C powder with 50% iridium loading, adding 98g of n-propanol solvent, and ultrasonically stirring and dispersing at room temperature for 12 hours to obtain catalyst slurry 2 with the content of 2%;

weighing 5g of 10% of a compound with a structure of-OCF₂CF₂CF₂SO₃Adding 50g of deionized water into the short side chain perfluorosulfonic acid resin liquid of H, and ultrasonically stirring at room temperature for 12H to obtain binder slurry 3 with the particle size of resin dispersed particles being 100 nm;

weighing 2g of sulfonated cerium dioxide with the particle size of 5nm, adding the sulfonated cerium dioxide into 98g of n-propanol, and ultrasonically stirring at room temperature for 12 hours to obtain functional nanoparticle slurry 4 with the concentration of 2%;

(2) laying a Nafion212 membrane on an adsorption heating table of spraying equipment at the set temperature of 80 ℃, setting the vacuum degree to be-0.1 MPa, and adsorbing and flattening the membrane;

slurries

1, 3 and 4 prepared in the step (1) into one group of spray heads of spraying equipment, so that the three slurries are respectively linearly sprayed out from the three spray heads of the same group, injecting the three slurries into three slurry guide grooves of each spray head in batches through an injection pipe on each spray head, and then injecting the

slurries

1, 3 and 4 into each spray head of the group of spray heads according to the mode; so that the slurry is linearly sprayed out of the spray heads, wherein the gap between the spray heads is 2cm, the spraying speed is 200mm/s, and the spraying flow is as follows: spraying for 5 times, wherein the spray head corresponding to the slurry 1 is 10mL/min, the spray head corresponding to the slurry 3 is 5mL/min, the spray head corresponding to the slurry 4 is 2mL/min, and the ultrasonic frequency of each spray head is 60 Hz;

(4) respectively injecting the slurries 2, 3 and 4 prepared in the step (1) into a group of spray heads of a spraying device, so that the three slurries are respectively linearly sprayed from the three spray heads of the same group, injecting the three slurries into three slurry guide grooves of each spray head in batches through an injection pipe on each spray head, then injecting the slurries 2, 3 and 4 into each spray head of the group of spray heads according to the method, so that the slurries are respectively linearly sprayed from a plurality of spray heads, placing the front surface of the perfluorosulfonic acid membrane coated with the slurries 1, 3 and 4 on the front surface of the perfluorosulfonic acid membrane (3) close to an adsorption heating table, and starting to spray the slurries 2, 3 and 4 on the back surface of the membrane after vacuum adsorption, wherein the spraying gap is 2cm, the spraying speed is 200mm/s, and the spraying flow is as follows: spraying for 5 times with a nozzle corresponding to slurry 2 of 10mL/min, slurry 3 of 5mL/min and slurry 4 of 2mL/min and ultrasonic frequency of 60Hz to obtain membrane electrode CCM, wherein the loading of slurry 1 is 0.8mg/cm²The supporting amount of the slurry 2 is 1mg/cm²The 3 supporting amount of the sizing agent is 0.5mg/cm²The content of the slurry 4 is 0.1mg/cm²；

(5) And (4) hot-pressing the membrane electrode CCM prepared in the step (3), the carbon paper and the plastic frame at 100 ℃ to prepare the PEM water electrolysis membrane electrode.

Comparative example 1:

(1) preparing slurry:

weighing 2g of Pt/C catalyst powder with 50% Pt loading, adding 20g of 20% Pt/C catalyst powder with-OCF structure₂CF₂CF₂SO₃H, short-side-chain perfluorosulfonic acid resin solution, 76g of isopropanol solvent and 2g of sulfonated cerium dioxide with the particle size of 5nm are subjected to ultrasonic stirring and dispersion at room temperature for 20 hours to obtain catalyst slurry 1 with the content of 8%;

weighing 2g of iridium/C powder with 50% iridium loading, and adding 20g of 20% iridium/C powder with-OCF structure₂CF₂ CF₂SO₃H, short side chain perfluorosulfonic acid resin solution, 76g of isopropanol solvent and 2g of sulfonated cerium dioxide with the particle size of 5nm are ultrasonically stirred and dispersed for 20 hours at room temperature to obtain the catalyst with the content of 8 percentAgent slurry 2;

(3) spraying the catalyst slurry 1 prepared in the step (1) on the front surface of a Nafion212 membrane for 5 times by adopting a process of spraying at a spraying speed of 200mm/s, a spraying flow rate of 10mL/min and a nozzle ultrasonic frequency of 60 Hz;

(4) turning over the membrane with the front surface sprayed with the catalyst slurry 1 in the step (3) to enable the catalyst layer side to be attached to a platform and adsorbed, and then spraying the catalyst slurry 2 prepared in the step (1) on a Nafion212 membrane for 5 times by adopting a process of spraying at a speed of 200mm/s, a spraying flow of 10mL/min and a nozzle ultrasonic frequency of 60 Hz; obtaining a membrane electrode CCM with the front Pt loading of 0.8mg/cm²The content of iridium on the reverse side is 1mg/cm²；

Comparative example 2

(1) Preparing slurry:

weighing 5g of 10% of a compound with a structure of-OCF₂CF₂ CF₂SO₃Adding 50g of deionized water into the short side chain perfluorosulfonic acid resin liquid of H, and ultrasonically stirring at room temperature for 12H to obtain binder slurry 3 with the particle size of resin dispersed particles being 100 nm;

(2) laying a Nation212 membrane on an adsorption heating table of spraying equipment at the set temperature of 80 ℃, setting the vacuum degree to be-0.1 MPa, and adsorbing and flattening the membrane;

(3) firstly, controlling two groups of spray heads to be longitudinally arrayed above an adsorption heating table, then respectively injecting the slurries 1 and 3 prepared in the step (1) into one group of spray heads of spraying equipment, so that the two slurries are respectively linearly sprayed out from the two spray heads in the same group, injecting the two slurries into two slurry guide grooves of each spray head in batches through an injection pipe on each spray head, and then injecting the slurries 1 and 3 into each spray head in the group of spray heads according to the mode; so that the slurry is linearly sprayed out of the spray heads, wherein the gap between the spray heads is 2cm, the spraying speed is 200mm/s, and the spraying flow is as follows: spraying for 5 times, wherein the spray head corresponding to the slurry 1 is 10mL/min, the spray head corresponding to the slurry 3 is 5mL/min, and the ultrasonic frequency of each spray head is 60 Hz;

(4) injecting the slurries 2 and 3 prepared in the step (1) into a group of spray heads of a spraying device respectively to enable the two slurries to be linearly sprayed from the two spray heads of the same group respectively, injecting the two slurries into two slurry guide grooves of each spray head in batches through an injection pipe on each spray head, then injecting the slurries 2, 3 and 4 into each spray head of the group of spray heads according to the mode to enable the slurries to be linearly sprayed from a plurality of spray heads respectively, placing the front surface of the perfluorosulfonic acid membrane coated with the slurries 1, 3 and 4 on the front surface of the perfluorosulfonic acid membrane (3) close to an adsorption heating table, and starting to spray the slurries 2, 3 and 4 on the back surface of the membrane after vacuum adsorption, wherein the spraying gap is 2cm, the spraying speed is 200mm/s, and the spraying flow is as follows: spraying for 5 times with 10mL/min of spray head corresponding to slurry 2 and 5mL/min of spray head corresponding to slurry 3, and ultrasonic frequency of each spray head being 60Hz to obtain membrane electrode CCM, wherein the load of slurry 1 is 0.8mg/cm²The supporting amount of the slurry 2 is 1mg/cm²The 3 supporting amount of the sizing agent is 0.5mg/cm²；

Comparative example 3

(1) Preparing slurry:

weighing 5g of 10% perfluorosulfonic acid resin solution, adding 50g of deionized water, and ultrasonically stirring at room temperature for 12h to obtain binder slurry 3 with the particle size of resin dispersed particles being 100 nm;

slurries

(4) respectively injecting the slurries 2, 3 and 4 prepared in the step (1) into a group of spray heads of a spraying device, so that the three slurries are respectively linearly sprayed from the three spray heads of the same group, injecting the three slurries into three slurry guide grooves of each spray head in batches through an injection pipe on each spray head, then injecting the slurries 2, 3 and 4 into each spray head of the group of spray heads according to the method, so that the slurries are respectively linearly sprayed from a plurality of spray heads, placing the front surface of the perfluorosulfonic acid membrane coated with the slurries 1, 3 and 4 on the front surface of the perfluorosulfonic acid membrane (3) close to an adsorption heating table, and starting to spray the slurries 2, 3 and 4 on the back surface of the membrane after vacuum adsorption, wherein the spraying gap is 2cm, the spraying speed is 200mm/s, and the spraying flow is as follows: spraying for 5 times with spray head 10mL/min corresponding to slurry 2, spray head 5mL/min corresponding to slurry 3, and spray head 2mL/min corresponding to slurry 4, and ultrasonic frequency of each spray head 60Hz to obtain membrane electrode CCM, which is used for preparing membrane electrode assemblyThe content of the medium size 1 is 0.8mg/cm²The supporting amount of the slurry 2 is 1mg/cm²The 3 supporting amount of the sizing agent is 0.5mg/cm²The content of the slurry 4 is 0.1mg/cm²；

As can be seen from Table 1, the membrane electrode prepared by the multi-nozzle spraying method designed by the invention has better current density under the same voltage in the water electrolysis process, and the current density is 2000mA/cm under the electrolysis voltage of 2.0V²The above; in comparative example 1, the membrane electrode prepared by spraying the mixed slurry through a single nozzle had poor electrochemical performance, and the current density was 1895mA/cm at an electrolytic voltage of 2.0V²This is because the mixed slurry is difficult to disperse, and the components are mixed with each other, which has a certain coverage effect on the active sites of the catalyst, resulting in poor electrochemical performance. The difference between the comparative example 2 and the example 3 is that the functionalized nano particles are not used, and the experimental data shows that the current density of the membrane electrode is obviously lower than that of the example 3, because the functional nano particles can eliminate free radicals in the reaction process, but the functional nano particles are not added, and harmful groups such as free radicals generated in the reaction process can damage the service life of the membrane electrode and reduce the electrochemical performance; the comparative example 3 is different from the example 3 in that the perfluorosulfonic acid resin in the binder paste is not limited to short side chains, and it can be seen from experimental data that the resin having only long side chains has poor proton conductivity, and thus the current density of the membrane electrode is low.

TABLE 1 Membrane electrode Electrolysis Current Density Table

Examples	Current density mA/cm²@1.8V	Current density mA-cm²@2.0V
			1	1301	2013
2	1431	2132
			3	1378	2098
Comparative example 1	1100	1895
			Comparative example 2	1281	1987
Comparative example 3	1087	1675

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. A preparation method of a PEM water electrolysis CCM is characterized by comprising the following steps:

(1) preparing slurry: the slurry comprises catalyst slurry I, catalyst slurry II and binder slurryFunctional nano particle slurry; the solute of the binder slurry is short-side-chain perfluorosulfonic acid resin, and the side-chain molecular structure of the short-side-chain perfluorosulfonic acid resin is-OCF₂CF₂SO₃H、-OCF₂CF₂CF₂SO₃H、-OCF₂SO₃H; the functional nano-particles are one or more of nano-level phosphorylated cerium dioxide, sulfonated manganese dioxide, cerium dioxide and manganese dioxide;

(2) respectively feeding the catalyst slurry I, the binder slurry and the functional nanoparticle slurry, spraying on the front surface of the proton exchange membrane, and drying to finish spraying and feeding on the front surface of the proton exchange membrane;

(3) and (3) separating and feeding the catalyst slurry II, the binder slurry and the functional nanoparticle slurry, spraying on the back of the proton exchange membrane, and drying to obtain the CCM.

2. The method of claim 1 for making a PEM water electrolysis CCM, wherein: in the step (1), the catalyst slurry I is prepared in the following manner: adding the catalyst I into an alcohol solvent, and performing ultrasonic stirring at room temperature to obtain catalyst slurry I; the catalyst slurry II is prepared in the following way: adding the catalyst II into an alcohol solvent, and performing ultrasonic stirring at room temperature to obtain catalyst slurry II; in the catalyst slurry I and the catalyst slurry II, the alcohol solvent is one or more of ethanol, normal propyl alcohol, isopropanol, methanol and normal butanol respectively and independently, and the ultrasonic stirring time at room temperature is 1-10 hours.

3. The method of claim 1 for making a PEM water electrolysis CCM, wherein: in the step (1), the catalyst in the catalyst slurry I is a platinum-based catalyst, the platinum-based catalyst comprises one or a mixture of Pt/C, Pt black and Pt nanopowder, the catalyst in the catalyst slurry II is an iridium-based catalyst, and the iridium-based catalyst comprises one or a mixture of iridium/C, iridium black and iridium nanopowder; the solid content in the catalyst slurry I and the solid content in the catalyst slurry II are both 0.1-5 wt.%, and the catalyst loading is both 10-100 wt.%.

4. The method of claim 1 for making a PEM water electrolysis CCM, wherein: in the step (1), the binder slurry is prepared in the following manner: adding a short side chain perfluorosulfonic acid resin solution into a solvent for dilution and dispersion, and performing ultrasonic stirring at room temperature to obtain a binder slurry; the concentration of the binder slurry is 0.5-15 wt%, the solvent is deionized water or alcohol-water mixture, the mass concentration of the used short-side-chain perfluorosulfonic acid resin solution is 20%, wherein the short-side-chain perfluorosulfonic acid resin exists in the form of nano-dispersed particles, and the particle size of the nano-dispersed particles is 20-200 nm.

5. The method of claim 1 for making a PEM water electrolysis CCM, wherein: in the step (1), the functional nano particle slurry is prepared in the following manner; and adding the functional nanoparticles into a solvent for dispersion, and performing ultrasonic stirring at room temperature to obtain functional nanoparticle slurry, wherein the particle size of the functional nanoparticles is 1-10nm, the concentration of the functional nanoparticle slurry is 0.1-3 wt.%, and the solvent is one or more of ionized water, ethanol, isopropanol and n-butanol.

6. The method for preparing a PEM water electrolysis membrane electrode CCM as claimed in claim 1, wherein the method comprises the following steps: the load of each component of CCM is respectively as follows: platinum-based catalyst 0.3-1.2mg/cm²0.5-1.5mg/cm of iridium-based catalyst²Short side chain perfluorosulfonic acid resin 0.2-0.8mg/cm²0.05-0.3mg/cm of functional nano-particles²。

7. The method of claim 1 for making a PEM water electrolysis CCM, wherein:

in the steps (2) and (3), the proton exchange membrane is always in a heated state during spraying any slurry; the heating temperature of the proton exchange membrane is 50-100 ℃, the proton exchange membrane is heated by an adsorption heating table, and the vacuum degree of the adsorption heating table is-0.04 to-0.2 MPa; the spraying mode of the spray head is linear spraying, the spraying gap is 0.5-5cm, the spraying speed is 100-400mm/s, and the ultrasonic frequency of the spray head is 48-80 Hz;

in the step (2), the spraying flow rate of each slurry is respectively as follows: the catalyst slurry I is 0.5-20mL/min, the binder slurry is 1-10mL/min, and the functional nanoparticle slurry is 0.2-5 mL/min; the spraying times are repeated for 1-10 times.

8. The method of claim 1 for making a PEM water electrolysis CCM, wherein: the proton exchange membrane is a perfluorosulfonic acid membrane; the perfluorosulfonic acid membrane is one of Nafion115, 117, 211, 212 and a perfluorosulfonic acid composite membrane.

9. The method of claim 1 for making a PEM water electrolysis CCM, wherein: in the step (2) and the step (3), the spraying equipment for spraying the slurry comprises two groups of spray heads, the number of the spray heads in each group of spray heads is not less than 3, the distance between every two spray heads in each group of spray heads is 0.5-5cm, and the spray heads in each group of spray heads are arranged in a transverse array or a longitudinal array;

the shower nozzle is all including being cylindric nozzle body, the circumference array is equipped with the thick liquids direction recess of a plurality of semicircle forms on the outer periphery wall of nozzle body, the bottom of nozzle body is all run through to thick liquids direction recess, thick liquids direction recess all is equipped with the notes material pipe that supplies thick liquids to pour into, this internal coaxial air outlet channel who avoids thick liquids to appear the bias flow when flowing from each thick liquids direction recess of being equipped with of nozzle.

10. A PEM water electrolysis membrane electrode comprising a CCM prepared by the method of any of claims 1-9.