Proton Exchange Membrane Fuel Cell

Abstract

The present invention relates to a proton exchange membrane fuel cell. The proton exchange membrane fuel cell includes an anode catalyst layer, a cathode catalyst layer, a proton exchange membrane separating the anode catalyst layer from the cathode catalyst layer, an oxygen inlet configured to supply oxygen to the cathode catalyst layer, and a hydrogen inlet separate from the oxygen inlet and configured to supply hydrogen to the anode catalyst layer. The fuel cell is operable to convert hydrogen from the hydrogen inlet into hydrogen ions in the anode catalyst layer and produce H2O by-products in the cathode catalyst layer, wherein oxygen reacts with the hydrogen ions in the cathode catalyst layer. The fuel cell includes a water outlet for the H2O by-products, the water outlet being separate from the oxygen inlet.

Description

Technical Field

[0001] The present invention relates to fuel cells. More particularly, the present invention relates to proton exchange membrane fuel cells. Summary of the Invention

[0002] In one aspect, the present invention provides a proton exchange membrane fuel cell comprising an anode catalyst layer, a cathode catalyst layer, a proton exchange membrane separating the anode catalyst layer from the cathode catalyst layer, an oxygen inlet configured to supply oxygen to the cathode catalyst layer, and a hydrogen inlet separate from the oxygen inlet and configured to supply hydrogen to the anode catalyst layer. The fuel cell is operable to convert hydrogen from the hydrogen inlet into hydrogen ions in the anode catalyst layer and produce H 2 O by-products in the cathode catalyst layer, wherein oxygen reacts with hydrogen ions in the cathode catalyst layer. The fuel cell includes a water outlet for the H 2 O by-products, the water outlet being separate from the oxygen inlet.

[0003] In another aspect, the present invention provides a proton exchange membrane fuel cell comprising an anode catalyst layer, a cathode catalyst layer, a proton exchange membrane separating the anode catalyst layer from the cathode catalyst layer, an oxygen inlet configured to supply oxygen to the cathode catalyst layer, and a hydrogen inlet separate from the oxygen inlet and configured to supply hydrogen to the anode catalyst layer. The anode catalyst layer, the cathode catalyst layer, the oxygen inlet, and the hydrogen inlet are located on one side of the proton exchange membrane.

[0004] In yet another aspect, the present invention provides a proton exchange membrane fuel cell comprising an anode catalyst layer, a cathode catalyst layer, an oxygen inlet configured to supply oxygen to the cathode catalyst layer, a hydrogen inlet separate from the oxygen inlet and configured to supply hydrogen to the anode catalyst layer, a first hydrophobic layer located between the anode catalyst layer and the hydrogen inlet, a second hydrophobic layer located between the cathode catalyst layer and the oxygen inlet, and a hydrophilic drainage device positioned to receive H 2 O by-products generated in the cathode catalyst layer through the proton exchange membrane. Brief Description of the Drawings

[0005] Figure 1 is a schematic diagram of a prior art proton exchange membrane (PEM) fuel cell, where water is discharged through an air flow field.

[0006] Figure 2 is a schematic diagram of an interleaved back-contact PEM fuel cell.

[0007] Figure 3 is Figure 2 a schematic diagram of a back-to-back arrangement of multiple fuel cells of

[0008] Figure 4 isFigure 2 Schematic diagram of the first manufacturing process flow of a fuel cell.

[0009] Figure 5 is Figure 2 Schematic diagram of the second manufacturing process flow of a fuel cell.

[0010] Figure 6 Schematic diagram of an interleaved back contact PEM fuel cell according to another embodiment.

[0011] Figure 7 is Figure 6 Schematic diagram of the first manufacturing process flow of a fuel cell.

[0012] Figure 8 is Figure 6 Schematic diagram of the second manufacturing process flow of a fuel cell. Summary of the Invention

[0014] Before explaining any embodiment of the present invention in detail, it should be understood that the present invention is not limited in its application to the details of the construction and component arrangements set forth in the following description or shown in the following drawings. The present invention is capable of other embodiments and of being practiced or carried out in various ways.

[0015] Figure 1 Shows a prior art fuel cell 10 and, more particularly, a proton exchange membrane 34 (PEM) fuel cell 10. The fuel cell 10 includes electrodes 12, 14, a hydrogen supply channel 16, and an oxygen supply channel 18, and the oxygen supply channel 18 is separated from the hydrogen supply channel 16 by a fuel cell stack 22 including five layers.

[0016] The first and second layers of the fuel cell stack 22 are gas diffusion layers 24, 26 (GDL), and are respectively located adjacent to the hydrogen supply channel 16 and the oxygen supply channel 18. The gas diffusion layers 24, 26 are made of a carbon fiber-based porous material and provide a path for current collection. The third layer is an anode catalyst layer 28 (ACL). The anode catalyst layer 28 is located adjacent to the first gas diffusion layer 24 such that the first gas diffusion layer 24 is located between the anode catalyst layer 28 and the hydrogen supply channel 16. The catalyst causes the fuel to undergo an oxidation reaction, generating positively charged hydrogen ions (protons) and electrons in the anode catalyst layer 28. The oxidation reaction can be represented by H 2 → 2H + + 2e - represent.

[0017] The fourth layer is the cathode catalyst layer 30 (CCL). The cathode catalyst layer 30 is located adjacent to the second gas diffusion layer 26 such that the second gas diffusion layer 26 is located between the cathode catalyst layer 30 and the oxygen supply channel 18. Hydrogen ions react with oxygen from the oxygen supply channel 18 in the cathode catalyst layer 30 to produce water molecules. The reaction in the cathode catalyst layer 30 can be represented by O 2 + 4H + + 4e - → 2H 2 O.

[0018] The fifth layer is the proton exchange membrane 34 (PEM) located between the anode catalyst layer 28 and the cathode catalyst layer 30. The proton exchange membrane 34 allows hydrogen ions to conduct through it (from the anode catalyst layer 28 to the cathode catalyst layer 30), but prevents electrons from passing through it. Thus, Figure 1 the overall arrangement of the fuel cell 10 according to the layer sequence is the hydrogen supply channel 16 and electrode 12, the first gas diffusion layer 24, the anode catalyst layer 28, the proton exchange membrane 34, the cathode catalyst layer 30, the second gas diffusion layer 26, and then the oxygen supply channel 18 and electrode 14. Additional layers with different functions within the fuel cell 10 can be interspersed between the above five layers. The layers shown in the figure are not drawn to scale.

[0019] Figure 1 The operation of the fuel cell 10 as shown and described above produces water molecule by-products that need to leave the fuel cell stack 22. Typically, water is directed to the oxygen supply channel 18. When the fuel cell 10 operates at increased power density, the operation of the fuel cell 10 requires increased hydrogen and oxygen input through the respective supply channels 16, 18, resulting in a greater water output. The increased amount of water produced by this electrochemical process can lead to oxygen deficiency, where water molecules block the oxygen supply channel 18, limiting the amount of oxygen flowing into the cell 10. Similar mass transfer limitations also occur within the second gas diffusion layer 26 and within the cathode catalyst layer 30. Oxygen deficiency can also lead to a reduction in the durability of the fuel cell 10.

[0020] Figure 2 FIG. shows a schematic diagram of a fuel cell 110 and more particularly shows a proton exchange membrane fuel cell according to a first embodiment of the present disclosure that prevents or limits oxygen deficiency within the fuel cell 110. The fuel cell 110 includes hydrogen and oxygen supply channels 116, 118 and five inner layers that are similar to those of the Figure 1 fuel cell 10 shown, but the arrangement of these layers is modified. Both the hydrogen supply channel 116 and the oxygen supply channel 118 are located on the same side (i.e., the first side) of the fuel cell 110, rather than as Figure 1Shown on the opposite side. Further, both the gas diffusion layers 124 and 126, the anode catalyst layer 128, and the cathode catalyst layer 130 are located between the proton exchange membrane 134 and the supply channels 116 and 118.

[0021] The fuel cell 110 is configured in a staggered arrangement, in which a plurality of diaphragms 138 extend through the layers of the fuel cell 110, thereby dividing the first side of the fuel cell 110 into a plurality of sections 140 and 142. As shown, the diaphragms 138 extend between the electrodes 112 and 114 and the supply channels 116 and 118 and through the gas diffusion layers 124 and 126, the hydrophobic mesoporous layers 146 and 148 (described in more detail below), and the catalyst layers 128 and 130. The diaphragms 138 do not extend through the proton exchange membrane 134. The diaphragms 138 serve as separators to separate the fuel cell layers of adjacent sections 140 and 142 and prevent the flow of molecules (hydrogen, oxygen, water), protons (hydrogen ions), and electrons through the diaphragms 138. Each diaphragm 138 extends along the stacking direction of the fuel cell layers.

[0022] The first section 140 defined between adjacent diaphragms 138 includes the hydrogen supply channel 116, the first gas diffusion layer 124, and the anode catalyst layer 128. The second section 142 defined between adjacent diaphragms 138 includes the oxygen supply channel 118, the second gas diffusion layer 126, and the cathode catalyst layer 130. The first and second sections 140 and 142 are positioned adjacent to each other and are separated from each other laterally (perpendicular to the stacking direction of the layers) by the diaphragms 138. The diaphragms 138 terminate at the proton exchange membrane 134 such that the first and second sections 140 and 142 are connected to each other via the proton exchange membrane 134. The proton exchange membrane 134 provides a lateral path for the flow of molecules, protons, and electrons between the first and second sections 140 and 142. The pattern of alternating first and second sections 140 and 142 can be repeated in the width direction of the fuel cell 110. Since the diaphragms 138 terminate at the proton exchange membrane 134, the proton exchange membrane 134 is not divided into sections in the width direction corresponding to the repeated first and second sections 140 and 142, but is a single layer spanning multiple sections 140 and 142 and multiple diaphragms 138.

[0023] Figure 2 The fuel cell 110 further includes Figure 1Additional layers not included in the fuel cell 10 shown. A first hydrophobic mesoporous layer 146 (MPL) is located between the first gas diffusion layer 124 and the anode catalyst layer 128 within the first section 140. A second hydrophobic mesoporous layer 148 is located between the second gas diffusion layer 126 and the cathode catalyst layer 130 within the second section 142. The hydrophobic mesoporous layers 146, 148 prevent water from passing therethrough. Since water is mainly generated (as a by-product) at the cathode catalyst layer 130 within the fuel cell 110, the hydrophobic layers 146, 148 prevent water from reaching the oxygen supply channel 118 and the hydrogen supply channel 116.

[0024] The fuel cell 110 further includes adjacent electrodes 112, 114 and a separator 138 to complete a gas capping layer 150 of the stack 122. The gas capping layer 150 is an electrical insulator and a thermal conductor such that the flow of a coolant 152 (outside the fuel cell stack 122) can regulate the temperature of the fuel cell 110.

[0025] Water generated by the chemical process within the fuel cell 110 is discharged from the fuel cell 110, but there is a lack of Figure 1 discharge device options for the fuel cell 10 because the hydrophobic layers 146, 148 prevent water from reaching the supply channels 116, 118. In the fuel cell 110, a hydrophilic drainage device 154 (drainage capillary channels) is provided on the proton exchange membrane 134 on the side opposite the layered sections 140, 142 of the proton exchange membrane 134, thereby providing an outlet or discharge device for the water by-product. The hydrophilic drainage device 154 also provides mechanical support. Water oozes out of the proton exchange membrane 134 through the microporous structure of the drainage capillary channels 154. Water can be removed from the end of the discharge channel 154 by drying, heating, evaporation, pumping, adsorption or absorption of water.

[0026] The layers of the fuel cell 110 are not shown to scale, but are shown with exaggerated thicknesses for clarity. The proton exchange membrane 134 has a thickness of approximately 20 micrometers (e.g., 20 micrometers, 15 - 25 micrometers, 10 - 30 micrometers), and the gas diffusion layers 124, 126 have a thickness of approximately 200 - 500 micrometers. The anode and cathode catalyst layers 128, 130 are nanoparticle and / or polymer solutions that are applied on the gas diffusion layers 124, 126 or the proton exchange membrane 134 having a continuous pore network established upon drying.

[0027] In operation, hydrogen (H 2 ) is supplied from the hydrogen supply channel 116 through the first gas diffusion layer 124 and the first hydrophobic layer 146 to the first section 140 and is supplied to the anode catalyst layer 128. A chemical reaction occurs with the hydrogen, and hydrogen (H 2 ) is converted to hydrogen ions (H+ ) and electrons (e - ). Hydrogen ions pass through the proton exchange membrane 134, near the lateral side of the separator 138, and reach the cathode catalyst layer 130. Meanwhile, oxygen (O 2 ) is supplied from the oxygen supply channel 118 through the second gas diffusion layer 126 and the second hydrophobic layer 148 to the second section 142, and is supplied to the cathode catalyst layer 130. Oxygen (O 2 ) reacts with hydrogen ions (H + ) in the cathode catalyst layer 130 to generate water molecules (H 2 O). Water is guided away from the supply channels 116, 118 through the hydrophobic layers 146, 148 and instead passes through the proton exchange membrane 134 to the hydrophilic drainage device 154. For simplicity, although similar reactions occur at all positions along the lateral width of the fuel cell 110, arrows illustrating the flow of molecules and ions are shown only for a single pair of sections 140, 142.

[0028] Since water cannot pass through the first and second hydrophobic layers 146, 148 and an alternative drainage device is provided, the inlet channels 116, 118 (and especially the oxygen inlet 116) and the gas diffusion layers 124, 126 are not blocked by water molecules, thereby eliminating or limiting oxygen deficiency within the fuel cell 110. In addition, since the electrodes 112, 114 are on the same side of the membrane 134, fuel cell degradation that may occur due to membrane piercing (gas crossover, short circuit) is less likely to occur because proton and mass transport occur laterally rather than along the fuel cell in a layered or stacked direction.

[0029] Figure 3 An arrangement similar to Figure 2 is shown, in which two fuel cells 110 with separate fuel cell stacks are arranged back-to-back, with a shared single hydrophilic drainage device 154. In some embodiments, each fuel cell 110 has its own drainage device 154 such that the two drainage devices 154 are aggregated or connected together to act as a single central drainage device 154 for the assembled pair of fuel cells 110.

[0030] Figure 4 and 5 show a manufacturing workflow for producing the Figure 2 shown fuel cell structure. Figure 4 The process shown begins with assembling the initial gas diffusion layer 158, the initial hydrophobic layer 160, the initial catalyst layer 162, and the proton exchange membrane 134 into a stacked configuration. It is noted that Figure 4 the arrangement shown is relative to Figure 2The stacked arrangement shown is inverted. As shown, the initial gas diffusion layer 158 and the initial hydrophobic layer 160 are each formed as a single layer. The stack 122 is laser scribed to separate the single gas diffusion layer 158 into discrete rows including first and second gas diffusion layers 124, 126. Along the same discrete rows as the gas diffusion layers 124, 126, the laser scribing further separates the hydrophobic layer 160 into first and second hydrophobic layers 146, 148 and separates the initial catalyst layer 162 into an anode catalyst layer 128 and a cathode catalyst layer 130. The laser scribing does not separate the proton exchange membrane 134. The gap 164 created by the laser scribing is filled by depositing epoxy resin therein. The epoxy resin material solidifies to form a separator 138 for spatially separating the interleaved layers. Then finger electrodes 112, 114 are screen printed between the separators 138, and a gas barrier layer 150 is added above the electrodes 112, 114 to complete the stack 122.

[0031] As Figure 3 shown, two stacks 122 can be placed back-to-back and separated by a hydrophilic drainage device 154. The formation of the second stack 122 can be substantially the same as that of the first stack 122, but the same drainage device 154 is reused.

[0032] Figure 5 shown is a manufacturing workflow different from the Figure 4 workflow shown. Figure 4 The workflow shown utilizes an initial catalyst layer 162 that is divided into anode and cathode catalyst layers 128, 130 such that the anode and cathode catalyst layers 128, 130 are made of the same material. Figure 5 The workflow shown provides an assembly that can use a first material for the anode catalyst layer 128 and a different second material for the cathode catalyst layer 130.

[0033] In Figure 5 it, the epoxy resin is deposited on the proton exchange membrane 134 through a gap-patterned solid mask 166 made of metal and / or plastic. The deposited epoxy resin forms the separator 138. The epoxy resin separator 138 can be UV cured before removing the mask 166 because the epoxy resin separator 138 may have a high aspect ratio (e.g., height:width greater than 2:1). Figure 5A rectangular membrane 138 is shown, but the membrane can have angled sides to form a trapezoidal shape (i.e., formed as a trapezoidal mask geometry) to provide additional stability in cases where the membrane 138 has a high aspect ratio. Alternatively, the proton exchange membrane 134 itself can be fabricated to have these membrane grooves. Once the mask 166 is removed, the cathode catalyst layer 130 and the anode catalyst layer 128 are separately screen printed into different sections 140, 142 between the membranes 138. Separately screen printing the anode and cathode catalyst layers 128, 130 enables independent adjustment of the catalyst loading in the layers 128, 130. For example, it may be beneficial to provide a higher Pt catalyst loading to the cathode catalyst layer 130 than to the anode catalyst layer 128. With the anode and cathode catalyst layers 128, 130 in place, the hydrophobic layers 146, 148 and the gas diffusion layers 124, 126 are deposited on the anode and cathode catalyst layers 128, 130 in the membrane gap 164. The final steps are similar to those of Figure 4 In the middle of the gap 164, the positive and negative finger electrodes 112, 114 are screen printed and then the gas barrier layer 150 is placed.

[0034] Figure 6 FIG. shows a fuel cell 210 according to another embodiment. The fuel cell 210 is similar to the fuel cell 110 shown in Figure 2 wherein similar elements have similar reference numerals but incremented by 100. Compared to the fuel cell 110 that utilizes a parallel configuration of the electrodes 112, 114, the fuel cell 210 utilizes a series configuration of the electrodes 212, 214, where the positive and negative electrodes 212, 214 of each segment are shared and only the hydrogen and oxygen supply channels 216, 218 are separate.

[0035] In the arrangement shown in Figure 6 the proton exchange membrane is divided into a plurality of individual membranes 234, each proton exchange membrane 234 being associated with an adjacent pair of sections 240, 242. Dividing the proton exchange membrane 234 can prevent (or limit) ionic conduction short circuits. Additionally, the membranes 236, 238 are offset from each other (in the lamination direction) in a repeating pattern. The first membrane 236 extends between the hydrogen and oxygen supply channels 216, 218 and terminates at the proton exchange membrane 234, similar to the membrane 138 shown in Figure 2 The second membrane 238 is spaced from the gas barrier layer 250 to allow connection between the adjacent electrodes 212, 214. The second membrane 238 extends through the proton exchange membrane 234 and terminates at the hydrophilic drainage device 254. The first and second membranes 236, 238 alternate laterally. Thus, the proton exchange membranes 234 and the sections 240, 242 are separate but are connected to each other in a serpentine manner, which allows continuous lateral conduction of hydrogen ions (protons) and electrons. Figure 6The series arrangement shown in [Figure] enables a larger battery 210 to be achieved while limiting electrical losses, as the arrangement does not collect current through long, thin finger electrodes.

[0036] Figure 7 and 8 shows a manufacturing workflow for producing Figure 6 the fuel cell structure shown. Although it varies based on the differences between fuel cells 110, 210, Figure 7 the process shown is similar to Figure 4 the process shown. First, an initial gas diffusion layer 258, an initial hydrophobic layer 260, an initial catalyst layer 262, and a proton exchange membrane 234 are arranged in a stacked configuration. The stack 222 is cut by laser scribing to create discrete rows and gaps 264 between the separators 236, 238. Different from Figure 4 [Figure], in Figure 7 the laser scribing cuts to varying depths in a repeating pattern such that a first gap 264a extends only through the initial gas diffusion layer 258, the initial hydrophobic layer 260, and the initial catalyst layer 262, while a second gap 264b extends through the proton exchange membrane 234 in addition to these three layers 258, 260, 262. The fuel cell 210 includes a repeating pattern of first and second gaps 264a, 264b such that the proton exchange membrane 234 bridges each first gap 264a. Epoxy is deposited in the gaps 264 to define the separators 236, 238. As shown, the separator 236 within the second gap 264b extends above the gas diffusion layer 258, which helps to separate the hydrogen and oxygen supply channels 216, 218. The production of the separators 236, 238 can utilize masks (not shown) similar to those described for Figure 5 [Figure]. The separators 236, 238 are placed in position, and then these electrodes are screen printed between the separators 236, 238, and a gas barrier layer 250 is added above the electrodes 212, 214 to complete the stack 222. The gas barrier layer 250 is airtight to the separators 236, 238 to prevent lateral mixing of the fuel.

[0037] Figure 8 shows [Figure] in relation to Figure 7The manufacturing workflow shown is roughly the opposite of the manufacturing process. In this manufacturing workflow, the foundation or starting point of the assembly is the gas barrier layer 250, on which the electrodes 212, 214 are screen-printed. The initial gas diffusion layer 258 and the initial hydrophobic layer 260 are covered on the electrodes 212, 214. The anode catalyst layer 228 and the cathode catalyst layer 230 are screen-printed onto the stack 222, particularly above the hydrophobic layer 260. The stack 222 is cut by laser scribing, terminating at the gas barrier layer 250, thereby providing a gap 264a for the separator 236 that does not extend through the proton exchange membrane 234. These gaps 264a are filled with the epoxy resin separator 236. Then the proton exchange membrane 234 is applied to the stack 222. Additional gaps 264b are formed via laser scribing through the proton exchange membrane 234, the catalyst layers 228, 230, the hydrophobic layer 260, and the gas diffusion layer 258. These gaps 264b are aligned with the electrodes 212, 214 and terminate at the electrodes. Then, the gaps 264b are filled with the epoxy resin separator 238 by one of the methods described for Figure 4 , 5 or 7.

[0038] As shown and described above, both parallel and series configurations can be used for the fuel cells 110, 210. In addition, additional fuel cell designs can adopt a combination of these two configurations by correspondingly patterning the separators 138, 236, 238 and the layer deposits. Moreover, these configurations can be carried out as a continuous process (similar to roll-to-roll processing) rather than a batch manufacturing process.

[0039] The various features and advantages of the present invention are set forth in the appended claims.

Claims

1. A proton exchange membrane fuel cell, which comprises: an anode catalyst layer; a cathode catalyst layer; a proton exchange membrane; an oxygen inlet configured to supply oxygen to the cathode catalyst layer; a hydrogen inlet separate from the oxygen inlet and configured to supply hydrogen to the anode catalyst layer; a hydrophobic layer located between the oxygen inlet and the cathode catalyst layer, wherein the anode catalyst layer, the cathode catalyst layer, the oxygen inlet, and the hydrogen inlet are located on one side of the proton exchange membrane, wherein the proton exchange membrane fuel cell further comprises a hydrophilic drainage device located on the other side of the proton exchange membrane opposite to the one side.

2. The proton exchange membrane fuel cell according to claim 1, which further comprises a diaphragm located laterally between the anode catalyst layer and the cathode catalyst layer, wherein the diaphragm prevents the transmission of hydrogen and oxygen therethrough.

3. The proton exchange membrane fuel cell according to claim 1, which further comprises a first electrode adjacent to the hydrogen inlet, a second electrode adjacent to the oxygen inlet, a first gas diffusion layer between the hydrogen inlet and the anode catalyst layer, and a second gas diffusion layer between the oxygen inlet and the cathode catalyst layer.

4. The proton exchange membrane fuel cell according to claim 1, wherein the anode catalyst layer is laterally offset relative to the cathode catalyst layer.

5. The proton exchange membrane fuel cell according to claim 1, wherein the proton exchange membrane extends across one end of the diaphragm to connect the anode catalyst layer to the cathode catalyst layer.

6. The proton exchange membrane fuel cell according to claim 5, wherein the diaphragm is an epoxy resin protrusion extending from a gas barrier layer and terminating at the proton exchange membrane.

7. The proton exchange membrane fuel cell according to claim 1, which further comprises a first gas diffusion layer between the hydrogen inlet and the anode catalyst layer and a second gas diffusion layer between the oxygen inlet and the cathode catalyst layer.

8. The proton exchange membrane fuel cell according to claim 1, which further comprises a first electrode adjacent to the hydrogen inlet and a second electrode adjacent to the oxygen inlet.

9. The proton exchange membrane fuel cell according to claim 1, which further comprises a hydrophobic layer between the anode catalyst layer and the hydrogen inlet.

10. The proton exchange membrane fuel cell according to claim 1, wherein the proton exchange membrane serves as a fluid path between the anode catalyst layer and the cathode catalyst layer.

11. The proton exchange membrane fuel cell according to claim 1, wherein the hydrophilic drainage device is formed of a microporous structure configured to drain water away from the proton exchange membrane.

12. The proton exchange membrane fuel cell according to claim 1, wherein the anode catalyst layer is laterally separated from the cathode catalyst layer by an epoxy resin diaphragm.

13. Dual fuel cell assembly, comprising a proton exchange membrane fuel cell according to any one of claims 1 to 12, wherein the proton exchange membrane is a first proton exchange membrane, and the dual fuel cell assembly further comprises a second proton exchange membrane, the second proton exchange membrane being positioned such that the hydrophilic drainage device is located between the first proton exchange membrane and the second proton exchange membrane.

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