Catalyst film and monocell

Abstract

The present disclosure proposes a catalyst coating and a cell, the catalyst coating comprising: a proton exchange membrane (110); and a cathode-side catalyst layer (120) and an anode-side catalyst layer (130) coated on two opposite surfaces of the proton exchange membrane (110), the cathode-side catalyst layer (120) and the anode-side catalyst layer (130) forming two active regions (111) of the catalyst coating (100), and each of the cathode-side catalyst layer (120) and the anode-side catalyst layer (130) includes a support material attached to a surface of the proton exchange membrane (110) and a catalyst material attached to the support material, in which at least one active region (111) is composed of a central portion (111m) and a peripheral portion (111p) surrounding the central portion (111m), and wherein the support material has a higher hydrophobicity in the peripheral portion (111p) than in the central portion (111m).

Description

Technical Field

[0001] This disclosure relates to the field of fuel cell technology, and more specifically, to a catalyst coating for a fuel cell and a single cell including the catalyst coating. Background Technology

[0002] Fuel cells have become one of the main power generation technologies due to their high power generation efficiency, low environmental pollution, and high specific energy. As a typical fuel cell, the proton exchange membrane fuel cell (PEMFC) is a popular type of fuel cell used in vehicles. PEMFCs generally consist of a solid polymer electrolyte proton-conducting membrane, such as a perfluorosulfonic acid membrane. The anode and cathode typically comprise finely divided catalyst particles, usually platinum (Pt), supported on carbon particles and mixed with ionomers. The catalyst mixture is deposited on opposite sides of the membrane. The combination of the anode catalyst mixture, the cathode catalyst mixture, and the membrane defines the catalyst coating.

[0003] The fuel cell stack comprises multiple individual cells assembled together. Each individual cell includes a catalyst coating and an anode-side gas diffusion layer, an anode plate, a cathode-side gas diffusion layer, and a cathode plate located on both sides of the catalyst coating. The anode plate is provided with an anode gas flow field for supplying anode gas, which allows the supply of anode gas to the anode-side catalyst layer of the catalyst coating and the discharge of water from the anode-side catalyst layer. The cathode plate is provided with a cathode gas flow field for supplying cathode gas, which allows the supply of cathode gas to the cathode-side catalyst layer of the catalyst coating and the discharge of water from the cathode-side catalyst layer.

[0004] However, the existing fuel cell has relatively poor drainage capacity at the edges of the anode and cathode gas flow fields, which may cause water to flood the anode-side catalyst layer and the cathode-side catalyst layer from their respective edges inward, thereby affecting the efficiency of the electrochemical reaction and shortening the service life of the catalyst coating.

[0005] Therefore, there is an urgent need in the field for a technical solution that can promote drainage of the catalyst layer, especially the edge region of the catalyst layer, to prevent the catalyst layer from being flooded. Utility Model Content

[0006] To address the problems in the prior art, this disclosure proposes an improved catalyst coating comprising: a proton exchange membrane; and a cathode-side catalyst layer and an anode-side catalyst layer coated on two opposite surfaces of the proton exchange membrane, the cathode-side catalyst layer and the anode-side catalyst layer forming two active regions of the catalyst coating, and each of the cathode-side catalyst layer and the anode-side catalyst layer comprising a support material attached to the surface of the proton exchange membrane and a catalyst material attached to the support material, wherein at least one active region comprises a central portion and a peripheral portion surrounding the central portion, and wherein the support material is more hydrophobic in the peripheral portion than in the central portion.

[0007] According to one alternative embodiment of this disclosure, the porosity of the support material in the peripheral portion is greater than that in the central portion.

[0008] According to an optional embodiment of this disclosure, the active region formed by the anode-side catalyst layer consists of a central portion and a peripheral portion, wherein the porosity of the supporting material of the anode-side catalyst layer in the peripheral portion is greater than the porosity in the central portion.

[0009] According to an optional embodiment of this disclosure, the active region formed by the cathode-side catalyst layer consists of a central portion and a peripheral portion, wherein the porosity of the supporting material of the cathode-side catalyst layer in the peripheral portion is greater than the porosity in the central portion.

[0010] Similarly, in order to solve the problems in the prior art, this disclosure also proposes an improved single cell, which includes a cathode plate, an anode plate, a cathode-side gas diffusion layer, an anode-side gas diffusion layer, and a catalyst coating as described in this disclosure, stacked together along a stacking direction, wherein the cathode-side gas diffusion layer is located between the cathode plate and the cathode-side catalyst layer of the catalyst coating, and the anode-side gas diffusion layer is located between the anode plate and the anode-side catalyst layer of the catalyst coating.

[0011] According to an optional embodiment of this disclosure, the anode-side gas diffusion layer comprises an inner portion and an outer portion surrounding the inner portion, wherein the outer portion is more hydrophobic than the inner portion, and the outer portion and the inner portion are respectively aligned in the stacking direction with the peripheral and central portions of the active region formed by the anode-side catalyst layer.

[0012] According to an alternative embodiment of this disclosure, the outer portion of the anode-side gas diffusion layer completely covers the periphery of the active region formed by the anode-side catalyst layer.

[0013] According to an optional embodiment of this disclosure, the anode plate has an anode gas flow field on the surface facing the anode-side gas diffusion layer, and the outer portion of the anode-side gas diffusion layer is aligned with the anode gas flow field in the stacking direction.

[0014] According to an alternative embodiment of this disclosure, the anode plate has an anode gas flow field on its surface facing the anode-side gas diffusion layer, and the peripheral portion of the active region formed by the anode-side catalyst layer is aligned with the anode gas flow field in the stacking direction.

[0015] According to an optional embodiment of this disclosure, the cathode-side gas diffusion layer comprises an inner portion and an outer portion surrounding the inner portion, wherein the outer portion is more hydrophobic than the inner portion, and the outer portion and the inner portion are respectively aligned in the stacking direction with the peripheral and central portions of the active region formed by the cathode-side catalyst layer.

[0016] According to an alternative embodiment of this disclosure, the outer portion of the cathode-side gas diffusion layer completely covers the periphery of the active region formed by the cathode-side catalyst layer.

[0017] According to an optional embodiment of this disclosure, the cathode plate has a cathode gas flow field on the surface facing the cathode-side gas diffusion layer, and the outer portion of the cathode-side gas diffusion layer is aligned with the cathode gas flow field in the stacking direction.

[0018] According to an optional embodiment of this disclosure, the cathode plate has a cathode gas flow field on the surface facing the cathode-side gas diffusion layer, and the peripheral portion of the active region formed by the cathode-side catalyst layer is aligned with the cathode gas flow field in the stacking direction.

[0019] This disclosure may be embodied in the illustrative embodiments shown in the accompanying drawings. However, it should be noted that the drawings are merely illustrative, and any variations contemplated under the teachings of this disclosure should be considered to be included within the scope of this disclosure. Attached Figure Description

[0020] The accompanying drawings illustrate exemplary embodiments of this disclosure. These drawings should not be construed as necessarily limiting the scope of this disclosure, wherein:

[0021] Figure 1 This is a schematic exploded view of a single cell according to this disclosure;

[0022] Figure 2 yes Figure 1 A schematic front view of the anode plate of the single cell shown;

[0023] Figure 3 yes Figure 1 A schematic front view of the catalyst coating of a single cell shown;

[0024] Figure 4 yes Figure 1 A schematic front view of the gas diffusion layer on the anode side of the single cell shown; and

[0025] Figure 5 It is along Figure 1 A schematic exploded cross-sectional view of a single cell taken from line VV in the diagram. Detailed Implementation

[0026] Further features and advantages of this disclosure will become more apparent from the following description with reference to the accompanying drawings. Exemplary embodiments of this disclosure are shown in the drawings, and the drawings are not necessarily drawn to scale. However, this disclosure can be implemented in many different forms and should not be construed as necessarily limited to the exemplary embodiments shown herein. Rather, these exemplary embodiments are provided merely to illustrate this disclosure and to convey the spirit and essence of this disclosure to those skilled in the art.

[0027] This disclosure aims to provide an improved catalyst coating (CCM) for fuel cells. Due to its novel design, the catalyst coating promotes drainage of the catalyst layer, thereby preventing flooding and ensuring sufficient contact between the reactants and the catalyst material. It also prevents the catalyst coating's lifespan from being shortened due to flooding. Therefore, the catalyst coating according to this disclosure maintains the efficiency of the electrochemical reaction in the fuel cell, thereby increasing the fuel cell's output power, while also exhibiting high reliability and a long lifespan, thus improving the reliability and lifespan of the fuel cell. This disclosure also aims to provide an improved single cell for fuel cells, including the catalyst coating according to this disclosure and an improved gas diffusion layer. This gas diffusion layer, due to its novel design, promotes the drainage of water from the catalyst layer into the flow field of the bipolar plates, thereby more reliably preventing flooding of the catalyst layer, thus more effectively increasing the fuel cell's output power and improving its reliability and lifespan.

[0028] Various alternative, but non-limiting, embodiments of the single cell and catalyst coating according to this disclosure are described in detail below with reference to the accompanying drawings.

[0029] refer to Figure 1 A schematic exploded view of a single cell according to this disclosure is shown. Figure 1As shown, the single cell 10 has a multilayer structure in which multiple plate-shaped components are stacked and assembled along the stacking direction XX'. In other words, it is composed of multiple plate-shaped components stacked and assembled along the stacking direction XX'. Specifically, the single cell 10 includes a catalyst coating 100, a cathode-side gas diffusion layer 200 and an anode-side gas diffusion layer 300 located on both sides of the catalyst coating 100, and a cathode plate 400 and an anode plate 500 located on the outermost layers. The catalyst coating 100 includes a proton exchange membrane 110 and a cathode-side catalyst layer 120 and an anode-side catalyst layer 130 coated on two opposite surfaces of the proton exchange membrane 110. The cathode plate 400 is provided with a cathode gas flow field for the flow of cathode gas (e.g., compressed air from the atmosphere, an oxygen storage tank, or other cathode gas sources). The cathode-side gas diffusion layer 200... The cathode gas from the cathode gas flow field and electrons from the cathode plate 400 can be transported to the cathode-side catalyst layer 120, and water from the cathode-side catalyst layer 120 can be transported to the cathode gas flow field. The anode plate 500 is provided with an anode gas flow field for the flow of anode gas (e.g., hydrogen-containing gas from an anode gas source such as a hydrogen storage tank, or other hydrogen-containing gases such as methane or natural gas). The anode-side gas diffusion layer 300 can transport anode gas from the anode gas flow field to the anode-side catalyst layer 130 and electrons from the anode-side catalyst layer 130 to the anode plate 500. Furthermore, since water can permeate from the cathode-side catalyst layer 120 through the proton exchange membrane 110 to the anode-side catalyst layer 130, the anode-side gas diffusion layer 300 can also transport water from the anode-side catalyst layer 130 to the anode gas flow field.

[0030] It is worth mentioning that, although in Figure 1 In the illustrated embodiment, only one single cell 10 is shown, but this is merely exemplary. In embodiments not shown, multiple single cells 10 may be stacked and assembled together along the stacking direction XX' to form a fuel cell stack. In particular, adjacent cathode and anode plates may be combined to form bipolar plates, such that each bipolar plate transports anode gas supplied to one single cell 10 on one side and cathode gas supplied to another single cell 10 on the other side, and transports coolant for cooling the single cells 10 on both sides in the middle (i.e., between the cathode and anode plates).

[0031] During the operation of the single cell 10, the cathode gas and anode gas will undergo reduction and oxidation reactions at the cathode-side catalyst layer 120 and anode-side catalyst layer 130 of the catalyst coating 100, respectively, thereby generating electrical energy. Specifically, the cathode gas will flow through the cathode gas flow field of the cathode plate 400 and be diffused to the cathode-side catalyst layer 120 by the cathode-side gas diffusion layer 200, while the anode gas will flow through the anode gas flow field of the anode plate 500 and be diffused to the anode-side catalyst layer 130 by the anode-side gas diffusion layer 300. At the anode-side catalyst layer 130, the anode gas will decompose into protons and electrons under the action of the catalyst material (i.e., undergo an oxidation reaction: 2H₂→4H₂). + +4e - ), of which, proton (H + Electrons can travel from the anode-side catalyst layer 130 through the proton exchange membrane 110 to the cathode-side catalyst layer 120, while electrons (e - Since it cannot pass through the proton exchange membrane 110, it can only reach the cathode-side catalyst layer 120 through an external circuit. There, the cathode gas will combine with protons and electrons at the cathode-side catalyst layer 120 under the action of the catalyst material, thereby producing water (i.e., a reduction reaction occurs: O₂ + 4H₂). + +4e - →2H2O). In the above manner, the single cell 10 can generate electrical energy through the redox reaction (also known as electrochemical reaction) of the anode gas and the cathode gas to power the load on the external circuit. At the same time, water and heat are generated as byproducts. The water can be transported to the cathode gas flow field and the anode gas flow field by the cathode-side gas diffusion layer 200 and the anode-side gas diffusion layer 300 respectively and discharged with the cathode gas and the anode gas, while the heat can be absorbed by the coolant and discharged with the coolant.

[0032] As described above, as the electrochemical reaction proceeds, water is not only generated at the cathode-side catalyst layer 120, but also permeates through the proton exchange membrane 110 to the anode-side catalyst layer 130. If this water cannot be effectively drained, it will flood both the cathode-side catalyst layer 120 and the anode-side catalyst layer 130, thereby hindering the contact between the anode gas and cathode gas and the corresponding catalyst materials, and thus affecting the efficiency of the electrochemical reaction. In particular, the inventors of this disclosure have found that, in order to fully utilize the more expensive anode gas, the flow rate of the anode gas in the anode gas flow field is often lower than that of the cathode gas in the cathode gas flow field. This results in a smaller water pressure gradient between the anode gas flow field and the anode-side catalyst layer than between the cathode gas flow field and the cathode-side catalyst layer. Consequently, the water absorption capacity of the anode gas flow field is lower than that of the cathode gas flow field. Therefore, the anode-side catalyst layer 130 is more likely to be flooded than the cathode-side catalyst layer 120, and the catalyst coating 100 is more prone to hydrogen starvation. To ensure effective water drainage, this disclosure proposes the following drainage design. The drainage design according to this disclosure is described below with reference to the anode-side catalyst layer 130, the anode-side gas diffusion layer 300, and the anode plate 500. However, those skilled in the art will understand that this drainage design is equally applicable to the cathode-side catalyst layer 120, the cathode-side gas diffusion layer 200, and the cathode plate 400. Therefore, any improvement to any of the two catalyst layers, the two gas diffusion layers, and the two plates in accordance with the teachings of this disclosure is within the scope of protection of this disclosure.

[0033] refer to Figure 2 , which shows Figure 1 A schematic front view of the anode plate of a single cell. (As shown) Figure 2 As shown in the dashed box, the anode plate 500 has an anode gas flow field 510, two distribution zones 520 located on both sides of the anode gas flow field 510 (specifically, on both sides separated along the length direction L of the anode plate 500), two common conduit zones 530 located outside the two distribution zones 520, and a sealing zone 540 surrounding the anode gas flow field 510, the two distribution zones 520, and the two common conduit zones 530. Figure 2As shown, the anode gas flow field 510 is provided with multiple flow channels 511, each of which extends along the length direction L and is spaced apart from adjacent flow channels 511 along the width direction W of the anode plate 500; in other words, these flow channels 511 are arranged along the width direction W. Two distribution zones 520 are each provided with multiple distribution channels 521, each flow channel 511 being in fluid communication with one distribution channel 521 at one end and with another distribution channel 521 at the other end. Two common conduit zones 530 are each provided with an anode gas inlet 531 for receiving anode gas and an anode gas outlet 532 for discharging anode gas, wherein both the anode gas inlet 531 and the anode gas outlet 532 extend through the anode plate 500, thereby being aligned with corresponding openings in other components (e.g., catalyst coating 100, cathode plate 400, cathode plates of other single cells, catalyst coatings, and anode plates, etc.) to form a manifold for conveying anode gas. Of course, the two common pipeline areas 530 are also provided with cathode gas inlet 533, cathode gas outlet 534, coolant inlet 535 and coolant outlet 536 respectively, but since these openings are only used to form the manifold required for conveying cathode gas and coolant and are isolated from anode gas inlet 531 and anode gas outlet 532, each distribution channel 521 and each flow channel 511, these openings will not be described further.

[0034] like Figure 2 As shown, the anode gas inlet 531 and anode gas outlet 532 are fluidly connected to each distribution channel 521 in the adjacent distribution area 520. Therefore, each flow channel 511, together with the two distribution channels 521 on both sides, forms a flow path extending from the anode gas inlet 531 to the anode gas outlet 532. The anode gas from the anode gas inlet 531 can flow to the anode gas outlet 532 through each flow path. After the single cell 10 is assembled, each flow channel 511 is open towards the anode-side gas diffusion layer 300 in the stacking direction XX'. Therefore, the anode gas in each flow channel 511 can be diffused by the anode-side gas diffusion layer 300 to the anode-side catalyst layer 130 to participate in the electrochemical reaction as described above. It is worth mentioning that, as can be seen from the configuration of the anode gas flow field 510 and the distribution area 520, the angle between the flow channel 511 (hereinafter referred to as the outer flow channel) near the edge of the anode gas flow field 510 and the corresponding distribution channel 521 is inevitably sharper. This results in the anode gas flow velocity in the outer flow channel 511 being relatively low. Therefore, compared with the flow channel 511 (hereinafter referred to as the inner flow channel) near the center of the anode gas flow field 510, the water absorption capacity of the outer flow channel 511 is also relatively low.

[0035] refer to Figure 3, which shows Figure 1 A schematic front view of the catalyst coating on a single cell, as shown. Figure 3 As shown, the anode-side catalyst layer 130 is coated on the surface of the proton exchange membrane 110 facing the anode-side gas diffusion layer 300, thereby forming the active region 111 of the catalyst coating 100. After the single cell 10 is assembled, when viewed along the stacking direction XX', this active region 111 is aligned with the anode gas flow field 510 of the anode plate 500, so that the anode gas in the anode gas flow field 510 can reach the anode-side catalyst layer 130 after passing through the anode-side gas diffusion layer 300, and conversely, the water in the anode-side catalyst layer 130 can reach the anode gas flow field 510 after passing through the anode-side gas diffusion layer 300. It is worth mentioning that the description "two regions aligned" used herein means that when viewed along the stacking direction XX', the two regions at least partially overlap or coincide. Additionally, as... Figure 3 As shown, the proton exchange membrane 110 also has two common conduit regions 112 located on both sides of the active region 111 on its surface. The two common conduit regions 112 are respectively provided with an inlet and outlet for anolyte gas, an inlet and outlet for cathode gas, and an inlet and outlet for coolant. However, since no distribution area is provided between the active region 111 and the two common conduit regions 112, these openings in the two common conduit regions 112 are only used to form manifolds required for conveying anolyte gas, cathode gas and coolant, and are not in direct fluid communication with the active region 111 on the surface of the proton exchange membrane 110.

[0036] like Figure 3As shown, the anode-side catalyst layer 130 includes a support material (e.g., a carbon support made of carbon) attached to the surface of the proton exchange membrane 110 and a catalyst material (e.g., nanoparticles made of platinum or a platinum alloy) attached to the support material. The active region 111 consists of a peripheral portion 111p and a central portion 111m. The peripheral portion 111p is generally annular and surrounds or encircles the central portion 111m, such that the boundary line 111d between the peripheral portion 111p and the central portion 111m is located inside the edge 111e of the active region 111. In other words, the peripheral portion 111p is defined by the edge 111e and the boundary line 111d, while the central portion 111p is defined by the boundary line 111d. Part 111m is defined by boundary line 111d, and the anode-side catalyst layer 130 is configured such that the hydrophobicity of the support material in the peripheral part 111p is higher than that of the support material in the central part 111m. This can be achieved, for example, by making the porosity of the support material in the peripheral part 111p greater than that in the central part 111m, that is, by making the areal density (or apparent density) of the support material in the peripheral part 111p less than that in the central part 111m. The change in porosity can be achieved, for example, by adjusting the pore structure of the support materials in the peripheral part 111p and the central part 111m.

[0037] Under the above configuration, since the hydrophobicity of the support material in the outer portion 111p of the anode-side catalyst layer 130 is higher than that in the central portion 111m, the drainage capacity of the anode-side catalyst layer 130 in the outer portion 111p is higher than that in the central portion 111m. This makes it easier for water in the outer portion 111p to leave the anode-side catalyst layer 130 than for water in the central portion 111m. Therefore, even if the water absorption capacity of the outer flow channel 511 is relatively low, water in the outer portion 111p can still... The water in the central portion 111m can be efficiently discharged into the outer flow channels 511 through the anode-side gas diffusion layer 300. At the same time, since the inner flow channels 511 have a relatively high water absorption capacity, the water in the central portion 111m can also be efficiently discharged into the inner flow channels 511 through the anode-side gas diffusion layer 300. This achieves effective drainage of the entire active zone 111, thereby preventing the anode-side catalyst layer 130 from being flooded. As mentioned above, this not only ensures the efficiency of the electrochemical reaction, but also extends the service life of the catalyst coating 100. Furthermore, it is worth mentioning that even though increasing the porosity of the support material in the outer portion 111p improves its hydrophobicity, thereby reducing the areal density of the catalyst material in the outer portion 111p, the increased porosity of the support material in the outer portion 111p is more conducive to gas diffusion, thus promoting the electrochemical reaction. This compensates for the adverse effects of the reduced areal density of the catalyst material in the outer portion 111p on the electrochemical reaction. Therefore, the efficiency of the electrochemical reaction is not significantly adversely affected by the reduction in the areal density of the catalyst material in the outer portion 111p.

[0038] refer to Figure 4 , which shows Figure 1 A schematic front view of the gas diffusion layer on the anode side of a single cell. (See diagram.) Figure 4 As shown, the anode-side gas diffusion layer 300 consists of an outer portion 300p intended to be aligned with the peripheral portion 111p of the active region 111 of the catalyst coating 100, and an inner portion 300m intended to be aligned with the central portion 111m of the active region 111. The outer portion 300p is generally annular and surrounds or encircles the inner portion 300m, such that the boundary line 300d between the outer portion 300p and the inner portion 300m is located at the edge of the anode-side gas diffusion layer 300. The inner side of 300e, in other words, the outer portion 300p is defined by the edge 300e and the boundary line 300d, while the inner portion 300m is defined by the boundary line 300d. The anode-side gas diffusion layer 300 is configured such that the hydrophobicity of the outer portion 300p is higher than that of the inner portion 300m. This configuration can be achieved, for example, by changing the porosity, porosity gradient, surface coating, etc. of the diffusion layer material in the outer portion 300p and the inner portion 300m.

[0039] In the above configuration, since the hydrophobicity of the outer portion 300p of the anode-side gas diffusion layer 300 is higher than that of the inner portion 300m, on the one hand, the drainage capacity of the outer portion 300p is higher than that of the inner portion 300m, which is more conducive to the drainage of water into the outer flow channel 511. On the other hand, the water in the outer portion 300p diffuses into the inner portion 300m and then is discharged from the inner portion 300m into the inner flow channel 511, thereby forming an additional drainage path for the outer portion 111p of the active region 111 (i.e., outer portion 111p - outer portion 300p - inner portion 300m - inner flow channel 511). Therefore, the above configuration of the anode-side gas diffusion layer 300 combined with the above configuration of the catalyst coating 100 can more reliably achieve effective drainage of the entire active region 111, thereby more reliably preventing the anode-side catalyst layer 130 from being flooded.

[0040] refer to Figure 5 , which shows along Figure 1 A schematic exploded cross-sectional view of a single cell, taken from line VV. (See diagram below.) Figure 5 As shown, after the single cell 10 is assembled, when viewed along the stacking direction XX', the outer portion 300p of the anode-side gas diffusion layer 300 is aligned with the peripheral portion 111p of the active region 111. Specifically, when viewed along the stacking direction XX', the edge 300e of the anode-side gas diffusion layer 300 can be located outside the edge 111e of the active region 111, while the boundary line 300d between the outer portion 300p and the inner portion 300m of the anode-side gas diffusion layer 300 can be located inside the boundary line 111d between the peripheral portion 111p and the central portion 111m of the active region 111, so that the outer portion 300p of the anode-side gas diffusion layer 300 can completely cover the peripheral portion 111p of the active region 111. In this configuration, the entire peripheral portion 111p can be in contact with the outer portion 300p, thereby enabling the outer portion 300p to more effectively absorb water from the peripheral portion 111p and discharge the water into the anode gas flow field 510, thus more reliably preventing water flooding of the anode-side catalyst layer 130.

[0041] In particular, such as Figure 5As shown, when viewed along the stacking direction XX', the boundary line 111d between the outer portion 111p and the central portion 111m of the active region 111 is located inside the anode gas flow field 510, so that the outer portion 111p is aligned with at least the outer flow channel 511 in the stacking direction XX'. In this configuration, the outer portion 111p of the active region 111 is aligned with at least the outer flow channel 511 in the stacking direction XX'. If the boundary line 111d continues to advance inward, the outer portion 111p can be aligned with more flow channels 511, thereby allowing water in the outer portion 111p to be discharged more smoothly through the anode-side gas diffusion layer 300 (especially its outer portion 300p) into the anode gas flow field 510, thus more reliably preventing flooding of the anode-side catalyst layer 130.

[0042] In particular, such as Figure 5 As shown, when viewed along the stacking direction XX', the boundary line 300d between the outer portion 300p and the inner portion 300m of the anode-side gas diffusion layer 300 is located inside the anode gas flow field 510, such that the outer portion 300p is aligned with at least the outer flow channel 511 in the stacking direction XX'. In this configuration, the outer portion 300p of the anode-side gas diffusion layer 300 is aligned with at least the outer flow channel 511 in the stacking direction XX'. If the boundary line 300d continues to advance inward, the outer portion 300p can be aligned with more flow channels 511, thereby allowing the outer portion 300p to more smoothly discharge water from the peripheral portion 111p into the anode gas flow field 510, thus more reliably preventing water flooding of the anode-side catalyst layer 130.

[0043] Although the above description outlines a specific configuration of the anode-side catalyst layer 130, the anode-side gas diffusion layer 300, and the anode plate 500 for promoting drainage of the anode-side catalyst layer 130, those skilled in the art will understand that the configuration of the anode-side catalyst layer 130 can be applied to the cathode-side catalyst layer 120, the configuration of the anode-side gas diffusion layer 300 can be applied to the cathode-side gas diffusion layer 200, and the configuration of the anode plate 500 can be applied to the cathode plate 400 to promote drainage of the cathode-side catalyst layer 120. Therefore, modifications to the two catalyst layers, the two gas diffusion layers, and the two plates in accordance with the teachings of this disclosure to promote drainage of the two catalyst layers and thereby prevent flooding of the two catalyst layers are also within the scope of protection of this disclosure.

[0044] The above description, with reference to the accompanying drawings, details alternative but non-limiting embodiments of the catalyst coating and single cell according to this disclosure. Modifications and additions to the technology and structure, as well as recombinations of features in the various embodiments, will be readily apparent to those skilled in the art without departing from the spirit and essence of this disclosure and should be considered within its scope. Therefore, all such modifications and additions conceivable under the teachings of this disclosure should be considered part of this disclosure. The scope of this disclosure includes equivalent technologies known at the filing date of this disclosure and equivalent technologies not yet foreseen.

Claims

1. A catalyst coating, characterized in that, include: Proton exchange membrane (110); as well as A cathode-side catalyst layer (120) and an anode-side catalyst layer (130) are coated on two opposite surfaces of the proton exchange membrane (110). The cathode-side catalyst layer (120) and the anode-side catalyst layer (130) form two active regions (111) of the catalyst coating (100). Each of the cathode-side catalyst layer (120) and the anode-side catalyst layer (130) includes a support material attached to the surface of the proton exchange membrane (110) and a catalyst material attached to the support material. At least one active region (111) comprises a central portion (111m) and a peripheral portion (111p) surrounding the central portion (111m), and The supporting material is more hydrophobic in the outer portion (111p) than in the central portion (111m).

2. The catalyst coating according to claim 1, characterized in that, The porosity of the support material in the outer portion (111p) is greater than that in the central portion (111m).

3. The catalyst coating according to claim 1 or 2, characterized in that, The active region (111) formed by the anode-side catalyst layer (130) consists of a central portion (111m) and a peripheral portion (111p), wherein the porosity of the support material of the anode-side catalyst layer (130) in the peripheral portion (111p) is greater than that in the central portion (111m).

4. The catalyst coating according to claim 1 or 2, characterized in that, The active region (111) formed by the cathode-side catalyst layer (120) consists of a central portion (111m) and a peripheral portion (111p), wherein the porosity of the supporting material of the cathode-side catalyst layer (120) in the peripheral portion (111p) is greater than that in the central portion (111m).

5. A single battery, characterized in that, The assembly includes a cathode plate (400), an anode plate (500), a cathode-side gas diffusion layer (200), an anode-side gas diffusion layer (300), and a catalyst coating according to any one of claims 1-4, wherein the cathode-side gas diffusion layer (200) is located between the cathode plate (400) and the cathode-side catalyst layer (120) of the catalyst coating (100), and the anode-side gas diffusion layer (300) is located between the anode plate (500) and the anode-side catalyst layer (130) of the catalyst coating (100).

6. The single battery according to claim 5, characterized in that, The anode-side gas diffusion layer (300) consists of an inner portion (300m) and an outer portion (300p) surrounding the inner portion (300m). The outer portion (300p) is more hydrophobic than the inner portion (300m). The outer portion (300p) and the inner portion (300m) are respectively aligned in the stacking direction (XX') with the peripheral portion (111p) and the central portion (111m) of the active region (111) formed by the anode-side catalyst layer (130).

7. The single battery according to claim 6, characterized in that, The outer portion (300p) of the anode-side gas diffusion layer (300) completely covers the outer portion (111p) of the active region (111) formed by the anode-side catalyst layer (130).

8. The single battery according to claim 6 or 7, characterized in that, The anode plate (500) has an anode gas flow field (510) on its surface facing the anode-side gas diffusion layer (300), and the outer portion (300p) of the anode-side gas diffusion layer (300) is aligned with the anode gas flow field (510) in the stacking direction (XX').

9. The single cell according to any one of claims 5-7, characterized in that, The anode plate (500) has an anode gas flow field (510) on its surface facing the anode-side gas diffusion layer (300), and the peripheral portion (111p) of the active region (111) formed by the anode-side catalyst layer (130) is aligned with the anode gas flow field (510) in the stacking direction (XX').

10. The single battery according to claim 5, characterized in that, The cathode-side gas diffusion layer (200) consists of an inner portion and an outer portion surrounding the inner portion. The outer portion is more hydrophobic than the inner portion, and the outer portion and the inner portion are respectively aligned in the stacking direction (XX') with the peripheral portion (111p) and the central portion (111m) of the active region (111) formed by the cathode-side catalyst layer (120).

11. The single battery according to claim 10, characterized in that, The outer portion of the cathode-side gas diffusion layer (200) completely covers the outer portion (111p) of the active region (111) formed by the cathode-side catalyst layer (120).

12. The single battery according to claim 10 or 11, characterized in that, The cathode plate (400) has a cathode gas flow field on its surface facing the cathode-side gas diffusion layer (200), and the outer portion of the cathode-side gas diffusion layer (200) is aligned with the cathode gas flow field in the stacking direction (XX').

13. The single battery according to any one of claims 5, 10, and 11, characterized in that, The cathode plate (400) has a cathode gas flow field on its surface facing the cathode-side gas diffusion layer (200), and the peripheral portion (111p) of the active region (111) formed by the cathode-side catalyst layer (120) is aligned with the cathode gas flow field in the stacking direction (XX').

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