阅读说明：本技术 气体扩散层、其制备方法，对应的膜电极组件以及燃料电池 (Gas diffusion layer, method for producing same, corresponding membrane electrode assembly and fuel cell ) 是由 沈星汉 于 2019-12-31 设计创作，主要内容包括：本发明公开了一种气体扩散层,制备方法、膜电极组件以及燃料电池,本发明技术方案设置所述气体扩散层微孔层制备工艺中所用的浆料中特别添加了含有儿茶酚或含有邻苯二酚结构化合物的添加剂,特别是盐酸多巴胺。这样,能够显著气体扩散层材料的均一性、疏水性、导电性和耐久性,同时用该气体扩散层制备的燃料电池电堆性能有显著提升。(The invention discloses a gas diffusion layer, a preparation method, a membrane electrode assembly and a fuel cell. Therefore, the uniformity, hydrophobicity, conductivity and durability of the gas diffusion layer material can be obviously improved, and the performance of the fuel cell stack prepared by the gas diffusion layer is obviously improved.)

1. The gas diffusion layer is used for a fuel cell and is characterized by comprising a gas diffusion layer substrate and microporous layer slurry coated on the gas diffusion layer substrate, wherein an additive containing catechol or a catechol structure compound is added into the microporous layer slurry.

2. A method of preparing a gas diffusion layer for preparing a gas diffusion layer according to claim 1, the method comprising:

preparing microporous layer slurry, wherein the microporous layer slurry comprises a conductive material, a pore-forming agent, a hydrophobic agent and a dispersion liquid, and is uniformly mixed and dispersed;

coating the microporous layer slurry on the surface of the gas diffusion layer substrate subjected to hydrophobic treatment in a direct coating or screen printing mode; and

and roasting the gas diffusion layer coated with the microporous layer slurry.

3. A membrane electrode assembly, comprising:

a cathode-side gas diffusion layer, a cathode-side catalyst layer, a proton exchange membrane, an anode-side catalyst layer, and an anode-side gas diffusion layer which are stacked in this order;

wherein the cathode-side gas diffusion layer comprises the gas diffusion layer of any one of claims 1 to 18; the anode-side gas diffusion layer comprising the gas diffusion layer according to any one of claims 1 to 18.

4. A fuel cell, characterized in that the fuel cell comprises:

a fuel cell stack comprising a membrane electrode assembly, a plate, a collector, an insulator plate, a seal structure, and an end plate according to claim 3.

Technical Field

The invention relates to the technical field of fuel cells, in particular to a gas diffusion layer, a preparation method, a membrane electrode assembly and a fuel cell.

Background

As an alternative energy technology, fuel cells have attracted considerable attention and continued research and development due to their characteristics of convenience in starting, high energy density, zero emission, and high energy conversion efficiency, and have been widely used as power sources for automobiles, communication base stations, portable electric tools, and the like. As a power supply system for commercial application, the power supply system has the outstanding advantages of long enough service life and high energy density, such as application to standby power supplies, passenger vehicles, material transport vehicles, submarines and the like.

Proton exchange membrane fuel cells are the most mature, closest to commercially available fuel cells. The gas diffusion layer mainly plays five roles in the membrane electrode of the proton exchange membrane fuel cell: the method comprises the following steps of firstly, supporting a proton exchange membrane and a catalytic layer; secondly, transmitting the cathode and anode reaction gas in the flow field flow channel to the surface of the catalyst through molecular diffusion and Knudsen; third, electrons generated from the catalytic layer are transferred to the plate. Fourthly, water produced by the catalyst layer is transmitted to the flow channel for timely removal through capillary effect, concentration diffusion and the like in the gas diffusion layer, and mass transfer polarization is avoided. Fifth, the method comprises the following steps: in some cases, the gas diffusion layer functions to adhere the catalyst layer, and the catalyst layer is directly coated on the surface of the gas diffusion layer. The commonly used gas diffusion layer uses carbon fiber as a raw material, raw paper is prepared by wet papermaking or non-woven dry method, and then raw paper of the gas diffusion layer is prepared by carbonization and graphitization engineering. Because the surface of the carbon fiber is hydrophilic or not very hydrophobic, water generated in the fuel cell or input water is accumulated in the gas diffusion layer and is difficult to discharge, so that reaction gas cannot be transmitted to the surface of the catalyst in time, severe mass transfer polarization is generated, and the performance of the cell is reduced.

From the above description, how to ensure the gas transmission balance in the fuel cell to ensure the fuel cell has better performance is a problem to be solved urgently in the fuel cell field.

Disclosure of Invention

In order to solve the problems, the technical scheme of the invention provides a gas diffusion layer, a preparation method, a membrane electrode assembly and a fuel cell, which can ensure the gas transmission balance in the fuel cell.

In order to realize the above problem, the present invention provides the following technical solutions:

a gas diffusion layer used for a fuel cell, wherein catechol or an additive containing catechol structure compound, especially dopamine hydrochloride, is added into slurry used in a microporous layer treatment process.

In some embodiments, the gas diffusion layer is treated with dopamine hydrochloride in a slurry used in the microporous layer treatment process.

In some embodiments, the slurry used in the microporous layer process is composed of conductive material, pore-forming agent, hydrophobic agent, dispersion liquid, etc.

In some embodiments, the slurry used in the microporous layer process of the gas diffusion layer includes a conductive material, a pore former, a hydrophobic agent, and a dispersion.

In some embodiments, the conductive material of the gas diffusion layer in the slurry used in the microporous layer is carbon black; in some embodiments, the pore former comprises one or both of ammonium carbonate, ammonium oxalate, lithium carbonate; in some embodiments, the hydrophobic agent is an aqueous polytetrafluoroethylene dispersion, and the additive is added with catechol or an additive containing catechol-structure compound, and particularly can be dopamine hydrochloride.

In some embodiments, the dispersion is an alcohol.

In some embodiments, the gas diffusion layer has a thickness of 10 μm to 500 μm.

The invention also discloses a preparation method for preparing the gas diffusion layer, which comprises the following steps: preparing microporous layer slurry, wherein the microporous layer slurry comprises a conductive material, a pore-forming agent, a hydrophobic agent and a dispersion liquid, and is uniformly mixed and dispersed; coating the microporous layer slurry on the surface of the gas diffusion layer substrate subjected to hydrophobic treatment in a direct coating or screen printing mode; and roasting the gas diffusion layer coated with the microporous layer slurry.

In some embodiments, the gas diffusion layer is treated with dopamine hydrochloride in a slurry used in the microporous layer treatment process.

In some embodiments, the slurry used in the microporous layer process of the gas diffusion layer includes a conductive material, a pore former, a hydrophobic agent, and a dispersion.

In some embodiments, the conductive material of the gas diffusion layer in the slurry used in the microporous layer is carbon black;

in some embodiments, the pore former comprises one or both of ammonium carbonate, ammonium oxalate, lithium carbonate;

in some embodiments, the hydrophobic agent is an aqueous polytetrafluoroethylene dispersion, with the addition of catechol or an additive containing catechol-based compound (particularly dopamine hydrochloride).

In some embodiments, the dispersion is an alcohol.

In some embodiments, the gas diffusion layer has a thickness of 10 μm to 500 μm.

The present invention also encompasses a membrane electrode assembly, characterized in that it comprises:

a cathode-side gas diffusion layer, a cathode-side catalyst layer, a proton exchange membrane, an anode-side catalyst layer, and an anode-side gas diffusion layer which are stacked in this order;

wherein the gas diffusion layer at the cathode side is prepared by the gas diffusion layer microporous layer treatment process; the gas diffusion layer on the anode side is prepared by the gas diffusion layer microporous layer treatment process;

the present invention also discloses a fuel cell, characterized in that the fuel cell comprises:

the fuel cell stack is composed of the membrane electrode assembly, a polar plate, a collector plate, an insulating plate, a sealing structure, an end plate and the like.

The additive containing catechol or catechol structure compound, especially dopamine hydrochloride, is added into the microporous layer slurry. The aromatic ring functional group in the substance is a unit with a pi-pi conjugated structure, is similar to a carbon-carbon chemical bond structure on the surface of carbon fiber subjected to high-temperature graphitization treatment, can be well contacted and dispersed, and meanwhile, an adjacent dihydroxy structure on the aromatic ring has good conductivity, so that the conductivity of the microporous layer is improved, and the aromatic ring functional group can be well contacted with a polytetrafluoroethylene molecular chain and is well mutually soluble with an alcohol solvent in a polytetrafluoroethylene solution. Particularly, dopamine hydrochloride containing a catechol structure has an amino acid structure functional group, and can further increase the bonding between the solution of polytetrafluoroethylene and carbon fibers. The functional group with the amino acid structure can be naturally decomposed to produce gas to be discharged when being subjected to high-temperature treatment in the later process, and is a pore-forming agent which can increase the porosity of the gas diffusion layer material. In fact, the knowledge of the attachment ability of the catechol group is derived from the substances secreted on the antennae of marine organisms of shellfish, which may be attached to a variety of different surfaces, because the catechol group is present in the adhesion proteins secreted by the antennae. The compound containing the catechol group can imitate the miraculous adhesion capability of shellfish, so that the polytetrafluoroethylene can be tightly adhered to the surface of the carbon fiber of the gas diffusion layer.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic flow chart of a preparation method provided by an embodiment of the invention;

fig. 2 is a schematic structural diagram of a membrane electrode assembly according to an embodiment of the present invention;

fig. 3 is a comparison of the test performance results of the cells prepared according to the example of the present invention and the cells prepared according to the conventional scheme.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In general, the basic components of a proton exchange membrane fuel cell include: polar plate, gas diffusion layer, catalyst layer and proton exchange membrane.

The electrode plate can be divided into a unipolar plate and a bipolar plate, and has the functions of separating each single cell in the cell stack, conveying fuel and oxygen to the gas diffusion layer through a channel on the electrode plate, and meanwhile, having high conductivity so as to lead current to the outside.

The gas diffusion layer, the catalyst layer and the proton exchange membrane constitute a membrane electrode assembly. The gas diffusion layer is located between the catalyst layer and the plate, is one of the key materials in a proton exchange membrane fuel cell, is the outermost layer of the membrane electrode assembly, provides contact between the membrane electrode assembly and the plate, distributes reactants to the catalyst layer, and allows reaction product water to leave the electrode surface, allowing water to pass between the electrode and the flow channel.

In view of the above requirements, the material for the gas diffusion layer, which is currently being used in the fuel cell in a mature state, is a porous carbon material, such as carbon paper (e.g., carbon fiber paper) or carbon cloth (e.g., carbon fiber cloth), and is coated with a microporous layer on one surface thereof. In order to improve the transport of the reaction gas and liquid water in the gas diffusion layer, a hydrophobic treatment is generally performed on carbon paper or carbon cloth to construct hydrophobic gas-phase channels.

Generally, a carbon powder layer is formed on the surface of the gas diffusion layer to improve the pore structure of the gas diffusion layer, and the carbon powder layer has the functions of reducing the contact resistance between the catalyst layer and the gas diffusion layer, providing a better pore structure and hydrophobicity, redistributing gas and water, and preventing the electrode catalyst layer from being flooded. The hydrophobic agent and the capillary action of micropores in the microporous layer enable the microporous layer to have good hydrophobic and water-draining properties, so that stable gas channels and water channels are provided for fuel cell reaction, and the conductive carbon black in the microporous layer enables the microporous layer to have good electronic channels. The addition of the catalyst realizes the redistribution of reaction gas and reaction product water between a flow field and a catalyst layer, and plays an important role in enhancing the conductivity, improving the electrode performance, enhancing the operation stability of the battery and prolonging the operation life.

A microporous layer structure of a conventional fuel cell comprises a microporous layer with high water vapor permeability and a microporous layer with low water vapor permeability which are sequentially stacked; the stacking direction is perpendicular to the air flow path direction. The thickness of the microporous layer with high water vapor permeability is gradually increased and the thickness of the microporous layer with low water vapor permeability is gradually decreased along the air flow path direction, and the total thickness of the microporous layer structure is kept consistent.

However, the surface of the carbon fiber is hydrophilic, and is not easy to combine with hydrophobic Polytetrafluoroethylene (PTFE) emulsion, and although the conventional slurry preparation method can solve the problem that the gas diffusion layer material is hydrophobic, the polytetrafluoroethylene is not uniformly distributed on the surface of the carbon fiber and is easy to agglomerate. Particularly, in the long-term operation process of the fuel cell stack, especially the operation condition of the fuel cell stack for vehicles is very complicated and harsh, and the fuel cell stack is subjected to thousands of times of dry-wet cycles and cold-heat shock for tens of thousands of operating lives. When failure analysis of a membrane electrode which is a core component of a fuel cell stack is carried out, a microporous layer in a gas diffusion layer is separated from a substrate layer to generate a larger gap space, so that liquid water is accumulated at the position to cause local flooding, reaction gas is prevented from diffusing to the surface of a catalyst to cause mass transfer polarization to cause local reversal, and finally the actual effect of membrane electrode voltage reduction or perforation is caused. It is generally believed that when the fuel cell stack is at below freezing temperature, the liquid water remaining in the gas diffusion layer freezes, expands in volume, and melts again as the temperature increases, so that after such a number of repetitions, the gap space becomes larger and larger. Particularly where the microporous layer is in contact with the substrate layer, it is more likely to trap liquid water and thus to fail first due to the material difference between the two.

The additive containing catechol or catechol structure compound, especially dopamine hydrochloride, is added into the microporous layer slurry. The aromatic ring functional group in the substance is a unit with a pi-pi conjugated structure, is similar to a carbon-carbon chemical bond structure on the surface of carbon fiber subjected to high-temperature graphitization treatment, can be well contacted and dispersed, and meanwhile, an adjacent dihydroxy structure on the aromatic ring has good conductivity, so that the conductivity of the microporous layer is improved, and the aromatic ring functional group can be well contacted with a polytetrafluoroethylene molecular chain and is well mutually soluble with an alcohol solvent in a polytetrafluoroethylene solution. Particularly, dopamine hydrochloride containing a catechol structure has an amino acid structure functional group, and can further increase the bonding between the solution of polytetrafluoroethylene and carbon fibers. The functional group with the amino acid structure can be naturally decomposed to produce gas to be discharged when being subjected to high-temperature treatment in the later process, and is a pore-forming agent which can increase the porosity of the gas diffusion layer material. In fact, the knowledge of the attachment ability of the catechol group is derived from the substances secreted on the antennae of marine organisms of shellfish, which may be attached to a variety of different surfaces, because the catechol group is present in the adhesion proteins secreted by the antennae. The compound containing the catechol group can imitate the miraculous adhesion capability of shellfish, so that the polytetrafluoroethylene can be tightly adhered to the surface of the carbon fiber of the gas diffusion layer.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, fig. 1 is a schematic flow chart of a method for preparing a gas diffusion layer of a fuel cell according to an embodiment of the present invention, the method comprising:

step S11: and preparing microporous layer slurry, which consists of a conductive material, a pore-forming agent, a hydrophobic agent and a dispersion liquid, and uniformly mixing and dispersing.

The conductive material is carbon Black, preferably Vulcan XC-72(R) or ethylene Black. The pore-forming agent comprises one or two of ammonium carbonate, ammonium oxalate and lithium carbonate, and preferably ammonium oxalate. The water repellent agent is polytetrafluoroethylene aqueous dispersion, and is added with an additive containing catechol or a catechol-containing structural compound, in particular dopamine hydrochloride. The dispersion liquid is alcohol, the alcohol comprises one or two of ethanol, isopropanol and glycol, and isopropanol is preferred.

Step S12: and coating the slurry on the surface of the gas diffusion layer substrate subjected to hydrophobic treatment by a direct coating or screen printing mode, wherein the substrate can be carbon paper or carbon cloth.

Step S13: and placing the gas diffusion layer coated with the microporous layer into a drying oven for roasting treatment.

In some embodiments, the microporous layer slurry used in step S11 includes a conductive material, a pore former, a hydrophobic agent, and a dispersion liquid, and is uniformly mixed and dispersed.

Based on the above embodiment, another embodiment of the present invention further provides a membrane electrode assembly, which is shown in fig. 3, and fig. 3 is a description of each component of a fuel cell membrane electrode assembled by gas diffusion layers prepared according to the present invention, where 1 is a proton exchange membrane, 21 is an anode catalyst layer, 31 is an anode gas diffusion layer microporous layer, 41 is an anode gas diffusion layer substrate portion, 22 is an anode catalyst layer, 32 is an anode gas diffusion layer microporous layer, and 42 is an anode gas diffusion layer substrate portion.

Based on the above embodiments, another embodiment of the present invention also provides a fuel cell including the membrane electrode assembly according to the above embodiments.

The performance of the fuel cell (sample one) with the microporous layer structure according to the present invention and the performance of the fuel cell (sample two) prepared by the conventional technology are illustrated by combining specific design parameters.

Sample one: the technical scheme of the embodiment of the invention prepares the microporous layer structure

1) Weighing 3.2g of Vulcan XC-72(R), 60ml of aqueous solution containing 2.5g of ammonium oxalate, 8g of 20% PTFE diluent and 0.08g of dopamine hydrochloride, pouring into a certain amount of isopropanol, and uniformly stirring to prepare slurry with the viscosity of 300 cp;

2) coating the slurry on hydrophobic treated carbon paper (Toray H060 carbon paper is selected);

3) and (3) putting the gas diffusion layer coated with the slurry into a muffle furnace, heating at a heating rate of 5 ℃/min, finally roasting at 340 ℃ for 60min, and taking the gas diffusion layer after the furnace temperature is reduced to room temperature to finish the preparation of the microporous layer.

The porosity of the gas diffusion layer prepared in this example was measured to be 53.1% and a thickness of 223 μm according to the following microporous layer porosity test method.

(2) Comparative example: preparation of microporous layer structure by traditional technical scheme

1) Weighing 3.2g of Vulcan XC-72(R), 60ml of aqueous solution containing 2.5g of ammonium oxalate and 8g of 20 percent PTFE diluent, pouring into a certain amount of isopropanol, and uniformly stirring to prepare slurry with the viscosity of 300 cp;

2) coating the slurry on hydrophobic treated carbon paper (Toray H060 carbon paper is selected);

3) and (3) putting the gas diffusion layer coated with the slurry into a muffle furnace, heating at a heating rate of 5 ℃/min, finally roasting at 340 ℃ for 60min, and taking the gas diffusion layer after the furnace temperature is reduced to room temperature to finish the preparation of the microporous layer.

The porosity of this sample was measured to be 48.2% and the thickness to be 219 μm according to the following microporous layer porosity test method.

In the examples of the present invention, the porosity of the microporous layer was measured by a dipping method. Firstly, weighing 1 the gas diffusion layer substrate layer with the area of a and the thickness of b1, which is subjected to hydrophobic treatment, in decane until the weight is constant (decane is used as wetting liquid and can be immersed into all pores of the diffusion layer substrate layer due to low surface energy, and the mass of the diffusion layer before and after immersion is determined by using a weighing method 2. then, weighing 3 the diffusion layer (comprising the substrate layer and the microporous layer) with the area of a and the thickness of b2, immersing in decane until the weight is constant, determining 4 the diffusion layer (comprising the substrate layer and the microporous layer) before and after immersion by using a weighing method, and calculating the porosity of the microporous layer by the following formula:

and (3) respectively assembling the two samples into a proton exchange membrane fuel cell with an active area of 200cm2, wherein the assembly mode of a gas diffusion layer prepared by the first sample and the flow directions of cathode and anode gases are the same as those shown in the attached figure 3, and detecting and comparing the electrochemical performance of the cell obtained by comparison. The detection environment of the data is: the cathode inlet pressure was the same as the anode inlet pressure, the anode inlet gas humidity was 50%, the cathode inlet gas humidity was 50%, and the other operating conditions were the same. The result shows that the voltage of the cell prepared by the sample I is still stable above the density of 1.0A/cm2, while the voltage of the cell prepared by the sample II is obviously reduced, and the phenomenon of mass transfer polarization occurs. Therefore, the fuel cell prepared by the technical scheme of the application has better self-humidifying effect and better cell performance.

The process conditions may be adjusted as necessary to form gas diffusion layers of different thicknesses, for example, to obtain a thickness of the gas diffusion layer of between 10 μm and 500 μm.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

The invention may be implemented by the following examples:

1. the gas diffusion layer is used for a fuel cell and is characterized by comprising a gas diffusion layer substrate and microporous layer slurry coated on the gas diffusion layer substrate, wherein an additive containing catechol or a compound containing a catechol structure is added into the microporous layer slurry.

2. The gas diffusion layer according to example 1, wherein dopamine hydrochloride is added to a slurry used in a microporous layer treatment process.

3. The gas diffusion layer structure according to example 1, wherein the slurry used in the microporous layer forming process of the gas diffusion layer comprises a conductive material, a pore-forming agent, a hydrophobic agent, and a dispersion liquid.

4. The gas diffusion layer structure according to example 1, wherein the gas diffusion layer includes a conductive material in a slurry used in the process of making the microporous layer, and the conductive material is carbon black.

5. The gas diffusion layer structure according to example 1, wherein the gas diffusion layer includes a pore-forming agent in a slurry used in the microporous layer process, and the pore-forming agent includes one or two of ammonium carbonate, ammonium oxalate, and lithium carbonate.

6. The gas diffusion layer structure according to example 1, wherein the gas diffusion layer comprises a hydrophobic agent in a slurry used in the microporous layer forming process, and the hydrophobic agent is an aqueous polytetrafluoroethylene dispersion, and catechol or an additive containing a catechol structure compound is added.

7. The gas diffusion layer structure according to example 1, wherein the gas diffusion layer includes a dispersion liquid, which is an alcohol, in a slurry used in the process of making the microporous layer.

8. The gas diffusion layer structure according to example 1, wherein the thickness of the gas diffusion layer is 10 μm to 500 μm.

9. The gas diffusion layer structure according to example 1, characterized in that,

9. a method of producing a gas diffusion layer, for producing the gas diffusion layer according to any one of examples 1 to 8, comprising:

preparing microporous layer slurry, wherein the microporous layer slurry comprises a conductive material, a pore-forming agent, a hydrophobic agent and a dispersion liquid, and is uniformly mixed and dispersed;

coating the microporous layer slurry on the surface of the gas diffusion layer substrate subjected to hydrophobic treatment in a direct coating or screen printing mode; and

and roasting the gas diffusion layer coated with the microporous layer slurry.

10. The method for producing a gas diffusion layer according to example 9, characterized in that: wherein the substrate may be a carbon paper or a carbon cloth.

11. The method for producing a gas diffusion layer according to example 9, wherein dopamine hydrochloride was added to the slurry for the microporous layer used for the gas diffusion layer.

12. The method of producing a gas diffusion layer according to example 9, characterized in that the microporous layer slurry used for the gas diffusion layer includes a conductive material, a pore-forming agent, a water repellent agent, and a dispersion liquid.

13. The method of manufacturing a gas diffusion layer according to example 9, characterized in that the conductive material in the slurry for the gas diffusion layer used in the microporous layer is carbon black.

14. The method of manufacturing a gas diffusion layer according to example 9, wherein the pore-forming agent includes one or two of ammonium carbonate, ammonium oxalate, and lithium carbonate.

15. The method for producing a gas diffusion layer according to example 9, wherein the water repellent agent is an aqueous polytetrafluoroethylene dispersion, and catechol or an additive containing a catechol structural compound is added.

16. The method of manufacturing a gas diffusion layer according to example 9, characterized in that the dispersion liquid is an alcohol.

17. The method for producing a gas diffusion layer according to example 15, wherein the additive containing the catechol structural compound is dopamine hydrochloride.

18. The method of producing a gas diffusion layer according to example 9, characterized in that the thickness of the gas diffusion layer is 10 μm to 500 μm.

19. A membrane electrode assembly, comprising:

a cathode-side gas diffusion layer, a cathode-side catalyst layer, a proton exchange membrane, an anode-side catalyst layer, and an anode-side gas diffusion layer which are stacked in this order;

wherein the cathode-side gas diffusion layer comprises a gas diffusion layer microporous layer as described in any one of examples 1 to 18; the anode-side gas diffusion layer includes the gas diffusion layer according to any one of examples 1 to 18.

20. A fuel cell, characterized in that the fuel cell comprises:

a fuel cell stack comprising the membrane electrode assembly, the electrode plate, the current collector plate, the insulator plate, the seal structure, and the end plate of example 19.