An observable flow field fuel cell

Abstract

This invention relates to the field of fuel cell technology, and in particular to an observable flow field fuel cell, comprising two end plates, two electrode assemblies, and a membrane electrode assembly (MEA). Each MEA has an electrode assembly and an end plate on its two sides. Each electrode assembly includes a non-transparent electrode plate, a current collector, and a transparent electrode plate. The current collector is positioned between the transparent and non-transparent electrode plates. The transparent electrode plate has a transparent flow channel, and the non-transparent electrode plate has a non-transparent flow channel that mates with the transparent flow channel. The end plates have end plate cavities for observing the movement and distribution of liquid water within the flow channels of the electrode assemblies during stack operation. The end plates use screws to press and fix the electrode assemblies and the MEA. The observable flow field fuel cell of this invention does not limit the flow field structure and can meet high overall structural reliability and manufacturing precision requirements, while also reducing the battery's internal resistance and flow resistance, resulting in high accuracy of experimental results.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell with observable flow field. Background Technology

[0002] Against the backdrop of international energy shortages and environmental degradation, the development and utilization of hydrogen energy is one of the important ways to achieve a low-carbon transition and implement environmental protection. Proton exchange membrane fuel cells (PEMFCs) are energy conversion devices that use hydrogen to generate electricity. They are characterized by zero pollution, high efficiency, and low noise, and have attracted keen attention from governments, enterprises, and research institutions worldwide.

[0003] The proper functioning of a fuel cell is greatly influenced by its internal water balance; poor water management can lead to performance degradation and reduced durability. As a key component of the fuel cell stack, the flow field plate's excellent flow field design ensures more uniform gas distribution within the reaction zone and prevents excessive accumulation of liquid water within the flow channels, thus avoiding "flooding" of the cell. Numerical simulations can visualize the flow and distribution of liquid water within the flow field plate, but they suffer from issues such as fuzzy boundary conditions and difficulty in guaranteeing the accuracy of simulation results. Therefore, designing a fuel cell with an observable flow field would allow researchers to directly observe and analyze the movement behavior of liquid water within the flow channels, thereby evaluating the merits of the flow channel structure design and proposing directions for improvement and optimization.

[0004] In existing technologies (CN106887611A and CN212257564U), the design of fuel cell structures with observable flow fields mainly involves forming a visualization device using transparent end plates and hollowed-out metal plates, allowing observation of the fluid flow state within the plates. The existing scheme uses transparent end plates and hollowed-out metal plates to form a visualization device, but this scheme has the following disadvantages: (1) The hollowed-out portion of the metal plate and the transparent end plate are fitted together to form a flow channel, and the protrusions of the metal plate are fixed at both ends by reinforcing ribs. This method limits the flow channel structure design, meaning that the overall structural reliability and processing accuracy can only be satisfied under a parallel DC field; (2) Electrons generated by the reaction can only converge along the protrusions of the metal plate to the reinforcing ribs on both sides, and then be conducted to the outer metal frame. This method results in a line contact between the metal protrusion and the membrane electrode, leading to a large contact resistance, which in turn causes a large internal resistance and a large amount of heat generation. Furthermore, the thermal conductivity of the metal electrode is not as good as that of the graphite electrode, making it difficult for heat to dissipate. (3) In order to fix the metal protrusion, reinforcing ribs are set on both sides, and the flow area of ​​the transition zone where they are located is significantly smaller than that of the flow channel and the branch / convergence zone. This method leads to an increase in the internal flow resistance of the electrode channel and obstruction of liquid water discharge, affecting the experimental results. Summary of the Invention

[0005] The purpose of this invention is to provide an observable flow field fuel cell, solving the problems of narrow applicability, low reliability, and inaccurate observation results in existing transparent fuel cells. The observable flow field fuel cell of this invention does not limit the flow field structure and can meet high overall structural reliability and manufacturing precision, while reducing the internal resistance and flow resistance of the cell, resulting in high accuracy of experimental results.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] This invention provides an observable flow field fuel cell, comprising two end plates, two electrode assemblies, and a membrane electrode assembly, wherein an electrode assembly and an end plate are respectively disposed on two sides of the membrane electrode assembly;

[0008] The electrode assembly includes a non-transparent electrode, a current collector, and a transparent electrode. The current collector is disposed between the transparent electrode and the non-transparent electrode. The side of the transparent electrode close to the current collector is a transparent electrode mounting surface. A boss, a first air inlet hole, and a first air outlet hole are provided on the transparent electrode mounting surface. The boss is located in the middle of the transparent electrode mounting surface and has a transparent flow channel. The first air inlet hole and the first air outlet hole are located at the two ends of the transparent electrode.

[0009] The side of the non-transparent electrode plate away from the current collector is the non-transparent electrode plate mounting surface. The non-transparent electrode plate mounting surface is provided with an electrode plate cavity that matches the boss, a non-transparent flow channel, a second air inlet that matches the first air inlet, and a second air outlet that matches the first air outlet. The non-transparent flow channel is arranged around the electrode plate cavity.

[0010] The end plate is provided with an end plate cavity for observing the movement and distribution of liquid water in the flow channel of the electrode assembly during the operation of the fuel cell stack; the end plate presses and fixes the electrode assembly and membrane electrode through screws.

[0011] In one embodiment of the present invention, the boss can be of any shape, and a transparent flow channel is provided on the boss.

[0012] In one embodiment of the present invention, the first air inlet and the second air inlet are used to provide a channel for the reaction gas to enter the electrode assembly, and the first air outlet and the second air outlet are used to provide a channel for the reaction gas to flow out of the electrode assembly.

[0013] In one embodiment of the present invention, according to the actual design requirements of the fuel cell stack, a third air inlet and a third air outlet can be additionally provided on the transparent electrode plate; when a third air inlet or a third air outlet is provided, a fourth air inlet matching the third air inlet and a fourth air outlet matching the third air outlet are provided on the non-transparent electrode plate.

[0014] Furthermore, depending on the actual design requirements of the fuel cell stack, a third air inlet or a third air outlet may or may not be provided.

[0015] In one embodiment of the present invention, a first sealing groove and a second sealing groove are further provided on the transparent electrode plate assembly surface. The first sealing groove is arranged around the boss, and the second sealing groove is arranged around the first sealing groove, the first air inlet hole and the first air outlet hole.

[0016] A third sealing groove is also provided on the non-transparent electrode assembly surface, which surrounds the non-transparent flow channel, the second air inlet hole, and the second air outlet hole.

[0017] In one embodiment of the present invention, the current collector is provided with a current collector cavity, and the current collector cavity is matched with the electrode cavity;

[0018] The shape and size of the current collector plate match the first sealing groove. The current collector plate is embedded in the first sealing groove and mates with the transparent electrode plate mounting surface. The side of the current collector plate away from the first sealing groove is flush with the transparent electrode plate mounting surface.

[0019] In one embodiment of the present invention, the first sealing groove is bonded to the current collector plate with adhesive; the second sealing groove is sealed to the non-transparent electrode plate by a first sealing strip; and the third sealing groove is sealed to the membrane electrode by a second sealing strip.

[0020] In one embodiment of the present invention, the side of the non-transparent flow channel near the collector plate is flat and fits against the mounting surface of the transparent electrode plate;

[0021] The top surface of the boss is flush with the mounting surface of the non-transparent electrode plate. After assembly, the transparent flow channel and the non-transparent flow channel are connected to form a complete flow channel.

[0022] In one embodiment of the present invention, the end plate is provided with a plurality of screw holes around its perimeter, and the screw passes through the screw holes to press and fix the electrode assembly and the membrane electrode.

[0023] In one embodiment of the present invention, a collector plate cavity is provided on the collector plate, and the size, number and position of the collector plate cavity are consistent with those of the electrode plate cavity.

[0024] In one embodiment of the present invention, a hydrophobic coating is provided on the boss.

[0025] In one embodiment of the present invention, the transparent electrode plate is made of epoxy resin or polycarbonate transparent material with a thickness of 5-30 mm; the non-transparent electrode plate is made of graphite material with a thickness of 1-5 mm; the current collector is made of metal material with a thickness of 1-5 mm; and the end plate is formed of metal material with a thickness of 10-30 mm.

[0026] In one embodiment of the invention, the height of the boss is equal to the sum of the thickness of the current collector and the thickness of the non-transparent electrode plate.

[0027] In one embodiment of the present invention, after the electrode assembly is assembled, the transparent flow channel and the non-transparent flow channel are connected on the side of the non-transparent electrode opposite to the membrane electrode to form a complete flow channel; gas flows in the flow channel and contacts the membrane electrode to undergo a chemical reaction.

[0028] In one embodiment of the present invention, on the electrode assembly, a first transition channel for connecting the non-transparent flow channel and the second air inlet is provided on the side of the second air inlet near the non-transparent flow channel. The first transition channel is connected to the non-transparent flow channel through a flow divider.

[0029] In one embodiment of the present invention, on the electrode assembly, a second transition channel for connecting the non-transparent flow channel and the second air outlet is provided on the side of the second air outlet near the non-transparent flow channel, and the second transition channel is connected to the non-transparent flow channel through a confluence groove.

[0030] In one embodiment of the present invention, the depth of the transition channel is equal to the depth of the transparent channel, the non-transparent channel, the diversion channel, and the confluence channel.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] This invention provides an observable flow field fuel cell, addressing the problems of narrow applicability, low reliability, and inaccurate observation results in existing transparent fuel cell designs. The technical solution provided by this invention is not limited to a specific flow field structure, is simple, highly reliable, and has high processing precision, while simultaneously reducing the battery's internal and flow resistance and ensuring high accuracy of experimental results. By applying the transparent fuel cell designed according to this invention, researchers can directly observe and analyze the movement behavior of liquid water within the flow channel, thereby evaluating the merits of the flow channel structure design and proposing directions for improvement and optimization. Attached Figure Description

[0033] Figure 1 This is an exploded view of the observable flow field fuel cell in Example 1;

[0034] Figure 2 This is a schematic diagram of the endplate structure of the observable flow field fuel cell in Example 1;

[0035] Figure 3 This is a schematic diagram of the structure of the electrode assembly (view of the non-transparent electrode side after assembly) in the observable flow field fuel cell of Example 1;

[0036] Figure 4 This is a schematic diagram of the structure of the electrode assembly (view of the transparent electrode side after assembly) in the observable flow field fuel cell of Example 1;

[0037] Figure 5 This is a schematic diagram of the membrane electrode structure in the observable flow field fuel cell of Example 1;

[0038] Figure 6 This is an exploded structural diagram of the electrode assembly in Example 1;

[0039] Figure 7 This is a schematic diagram of the transparent electrode plate in the electrode plate assembly of Example 1;

[0040] Figure 8 This is a schematic diagram of the structure of the non-transparent electrode plate in the electrode plate assembly of Example 1;

[0041] Figure 9 This is a schematic diagram of the current collector plate in the electrode assembly of Example 1;

[0042] Figure 10 This is a partial cross-sectional view of the electrode assembly in Example 1;

[0043] Figure 11 This is a partial enlarged view of the electrode assembly in Example 1;

[0044] Numbering in the diagram: 100 - Electrode assembly; 200 - End plate; 300 - Membrane electrode;

[0045] 101 - Transparent electrode plate; 102 - Non-transparent electrode plate; 103 - Current collector plate;

[0046] 201 - End plate cavity; 202 - Screw hole;

[0047] 301 - First membrane electrode cavity; 302 - Second membrane electrode cavity; 303 - Third membrane electrode cavity; 304 - Fourth membrane electrode cavity;

[0048] 1011-First sealing groove; 1012-Second sealing groove; 1013-Transparent flow channel; 1014-First air inlet hole; 1015-First air outlet hole; 1016-Third air inlet hole; 1017-Third air outlet hole; 1018-Transparent electrode assembly surface;

[0049] 1021 - Third sealing groove; 1022 - Non-transparent flow channel; 1023 - Electrode cavity; 1024 - Second air inlet hole; 1025 - Second air outlet hole; 1026 - Fourth air inlet hole; 1027 - Fourth air outlet hole; 1028 - Non-transparent electrode assembly surface;

[0050] 1031 - Manifold cavity;

[0051] 1041 - Transition channel; 1042 - Diversion channel. Detailed Implementation

[0052] This invention provides an observable flow field fuel cell, comprising two end plates, two electrode assemblies, and a membrane electrode assembly, wherein an electrode assembly and an end plate are respectively disposed on two sides of the membrane electrode assembly;

[0053] The electrode assembly includes a non-transparent electrode, a current collector, and a transparent electrode. The current collector is disposed between the transparent electrode and the non-transparent electrode. The side of the transparent electrode close to the current collector is a transparent electrode mounting surface. A boss, a first air inlet hole, and a first air outlet hole are provided on the transparent electrode mounting surface. The boss is located in the middle of the transparent electrode mounting surface and has a transparent flow channel. The first air inlet hole and the first air outlet hole are located at the two ends of the transparent electrode.

[0054] The side of the non-transparent electrode plate away from the current collector is the non-transparent electrode plate mounting surface. The non-transparent electrode plate mounting surface is provided with an electrode plate cavity that matches the boss, a non-transparent flow channel, a second air inlet that matches the first air inlet, and a second air outlet that matches the first air outlet. The non-transparent flow channel is arranged around the electrode plate cavity.

[0055] The end plate is provided with an end plate cavity for observing the movement and distribution of liquid water in the flow channel of the electrode assembly during the operation of the fuel cell stack; the end plate presses and fixes the electrode assembly and membrane electrode through screws.

[0056] In one embodiment of the present invention, the boss can be of any shape, and a transparent flow channel is provided on the boss.

[0057] In one embodiment of the present invention, the first air inlet and the second air inlet are used to provide a channel for the reaction gas to enter the electrode assembly, and the first air outlet and the second air outlet are used to provide a channel for the reaction gas to flow out of the electrode assembly.

[0058] In one embodiment of the present invention, according to the actual design requirements of the fuel cell stack, a third air inlet and a third air outlet can be additionally provided on the transparent electrode plate; when a third air inlet or a third air outlet is provided, a fourth air inlet matching the third air inlet and a fourth air outlet matching the third air outlet are provided on the non-transparent electrode plate.

[0059] Furthermore, depending on the actual design requirements of the fuel cell stack, a third air inlet or a third air outlet may or may not be provided.

[0060] In one embodiment of the present invention, a first sealing groove and a second sealing groove are further provided on the transparent electrode plate assembly surface. The first sealing groove is arranged around the boss, and the second sealing groove is arranged around the first sealing groove, the first air inlet hole and the first air outlet hole.

[0061] A third sealing groove is also provided on the non-transparent electrode assembly surface, which surrounds the non-transparent flow channel, the second air inlet hole, and the second air outlet hole.

[0062] In one embodiment of the present invention, the current collector is provided with a current collector cavity, and the current collector cavity is matched with the electrode cavity;

[0063] The shape and size of the current collector plate match the first sealing groove. The current collector plate is embedded in the first sealing groove and mates with the transparent electrode plate mounting surface. The side of the current collector plate away from the first sealing groove is flush with the transparent electrode plate mounting surface.

[0064] In one embodiment of the present invention, the first sealing groove is bonded to the current collector plate with adhesive; the second sealing groove is sealed to the non-transparent electrode plate by a first sealing strip; and the third sealing groove is sealed to the membrane electrode by a second sealing strip.

[0065] In one embodiment of the present invention, the side of the non-transparent flow channel near the collector plate is flat and fits against the mounting surface of the transparent electrode plate;

[0066] The top surface of the boss is flush with the mounting surface of the non-transparent electrode plate. After assembly, the transparent flow channel and the non-transparent flow channel are connected to form a complete flow channel.

[0067] In one embodiment of the present invention, the end plate is provided with a plurality of screw holes around its perimeter, and the screw passes through the screw holes to press and fix the electrode assembly and the membrane electrode.

[0068] In one embodiment of the present invention, a collector plate cavity is provided on the collector plate, and the size, number and position of the collector plate cavity are consistent with those of the electrode plate cavity.

[0069] In one embodiment of the present invention, a hydrophobic coating is provided on the boss.

[0070] In one embodiment of the present invention, the transparent electrode plate is made of epoxy resin or polycarbonate transparent material with a thickness of 5-30 mm; the non-transparent electrode plate is made of graphite material with a thickness of 1-5 mm; the current collector is made of metal material with a thickness of 1-5 mm; and the end plate is formed of metal material with a thickness of 10-30 mm.

[0071] In one embodiment of the invention, the height of the boss is equal to the sum of the thickness of the current collector and the thickness of the non-transparent electrode plate.

[0072] In one embodiment of the present invention, after the electrode assembly is assembled, the transparent flow channel and the non-transparent flow channel are connected on the side of the non-transparent electrode opposite to the membrane electrode to form a complete flow channel; gas flows in the flow channel and contacts the membrane electrode to undergo a chemical reaction.

[0073] In one embodiment of the present invention, on the electrode assembly, a first transition channel for connecting the non-transparent flow channel and the second air inlet is provided on the side of the second air inlet near the non-transparent flow channel. The first transition channel is connected to the non-transparent flow channel through a flow divider.

[0074] In one embodiment of the present invention, on the electrode assembly, a second transition channel for connecting the non-transparent flow channel and the second air outlet is provided on the side of the second air outlet near the non-transparent flow channel, and the second transition channel is connected to the non-transparent flow channel through a confluence groove.

[0075] In one embodiment of the present invention, the depth of the transition channel is equal to the depth of the transparent channel, the non-transparent channel, the diversion channel, and the confluence channel.

[0076] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0077] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0078] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0079] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc., are only used for distinction in description and have no special meaning.

[0080] Example 1

[0081] This embodiment provides an observable flow field fuel cell, such as Figure 1-11 As shown, the device includes two end plates 200, two electrode assemblies 100, and a membrane electrode 300. An electrode assembly 100 and an end plate 200 are respectively disposed on two sides of the membrane electrode 300. The electrode assembly 100 includes a non-transparent electrode 102, a current collector 103, and a transparent electrode 101. The current collector 103 is disposed between the transparent electrode 101 and the non-transparent electrode 102. The side of the transparent electrode 101 closest to the current collector 103 is a transparent electrode mounting surface 1018. The transparent electrode mounting surface 1018 is provided with a boss (allowed to be of any shape), a first air inlet 1014, and a first air outlet 1015. The boss is located in the middle of the transparent electrode mounting surface 1018 and has a transparent flow channel 1013. The top of the boss is coated with a hydrophobic coating. The first air inlet 1014 and the first air outlet 1015... 015 is disposed at both ends of the transparent electrode plate 101; the side of the non-transparent electrode plate 102 away from the current collector 103 is a non-transparent electrode plate assembly surface 1028, on which the non-transparent electrode plate assembly surface 1028 is provided with an electrode plate cavity 1023 that matches the boss, a non-transparent flow channel 1022, a second air inlet 1024 that matches the first air inlet 1014, and a second air outlet 1025 that matches the first air outlet 1015; the non-transparent flow channel 1022 is arranged around the electrode plate cavity 1023; the end plate 200 is provided with an end plate cavity 201, which is used to observe the movement and distribution of liquid water in the flow channel of the electrode plate assembly 100 during the operation of the fuel cell stack; a number of screw holes 202 are provided around the end plate 200, and the screw passes through the screw holes 202 to press and fix the electrode plate assembly 100 and the membrane electrode 300.

[0082] The first inlet port 1014 and the second inlet port 1024 provide channels for the reactant gas to enter the electrode assembly 100, and the first outlet port 1015 and the second outlet port 1025 provide channels for the reactant gas to flow out of the electrode assembly 100. Depending on the actual design requirements of the fuel cell stack, a third inlet port 1016 and a third outlet port 1017 can be additionally provided on the transparent electrode plate 101. When a third inlet port 1016 or a third outlet port 1017 is provided... The non-transparent electrode plate 102 is provided with a fourth air inlet 1026 that matches the third air inlet 1016, and a fourth air outlet 1027 that matches the third air outlet 1017; furthermore, according to the actual design requirements of the fuel cell stack, the third air inlet 1016 or the third air outlet 1017 may or may not be provided (the attached figures are schematic diagrams showing the provision of the third air inlet 1016 and the third air outlet 1017); it should be noted that, as Figure 1 As shown, in the electrode assembly 100 above the membrane electrode 300, the first air outlet hole 1015, the second air outlet hole 1025, the third air inlet hole 1016, and the third air outlet hole 1017 provided on the transparent electrode 101 do not penetrate the transparent electrode 101; in the electrode assembly 100 below the membrane electrode 300, the first air outlet hole 1015, the second air outlet hole 1025, the third air inlet hole 1016, and the third air outlet hole 1017 provided on the transparent electrode 101 penetrate the transparent electrode 101.

[0083] The transparent electrode mounting surface 1018 is further provided with a first sealing groove 1011 and a second sealing groove 1012. The first sealing groove 1011 is arranged around the boss, and the second sealing groove 1012 is arranged around the first sealing groove 1011, the first air inlet hole 1014, and the first air outlet hole 1015. The non-transparent electrode mounting surface 1028 is further provided with a third sealing groove 1021. The third sealing groove 1021 is arranged around the non-transparent flow channel 1022, the second air inlet hole 1024, and the second air outlet hole 1025. The collector plate 103 is provided with a collector plate cavity 1031, which matches the electrode plate cavity 1023. The shape and size of the collector plate 103 are as follows: Matching the first sealing groove 1011, the current collector 103 is embedded in the first sealing groove 1011 and mates with the transparent electrode mounting surface 1018; the current collector 103 has a current collector cavity 1031, the size, number and position of which are consistent with the electrode cavity 1023; the side of the current collector 103 away from the first sealing groove 1011 is flush with the transparent electrode mounting surface 1018; the top surface of the boss is flush with the non-transparent electrode mounting surface 1028; the first sealing groove 1011 is bonded to the current collector 103 with adhesive; the second sealing groove 1012 is sealed to the non-transparent electrode 102 by the first sealing strip; the third sealing groove 1021 is sealed to the membrane by the second sealing strip. Electrode 300 is sealed; the non-transparent flow channel 1022 is flat on the side near the current collector 103 and fits against the transparent electrode assembly surface 1018; after the electrode assembly 100 is assembled, the transparent flow channel 1013 and the non-transparent flow channel 1022 are connected on the side of the non-transparent electrode 102 opposite to the membrane electrode 300 to form a complete flow channel; gas flows in the above flow channel and contacts the membrane electrode 300 to undergo a chemical reaction; on the electrode assembly 100, a first transition flow channel 1041 for connecting the non-transparent flow channel 1022 and the second air inlet 1022 is provided on the side of the second air inlet 1024 near the non-transparent flow channel 1022. 1. It is connected to the non-transparent flow channel 1022 through the flow divider 1042; on the electrode assembly 100, a second transition flow channel 1041 is provided on the side of the second air outlet 1025 near the non-transparent flow channel 1022 for connecting the non-transparent flow channel 1022 and the second air outlet 1025. The second transition flow channel 1041 is connected to the non-transparent flow channel 1022 through the flow combiner; the membrane electrode 300 is provided with a first membrane electrode cavity 301, a second membrane electrode cavity 302, a third membrane electrode cavity 303 and a fourth membrane electrode cavity 304 that match the second air inlet 1024, the second air outlet 1025, the fourth air inlet 1026 and the fourth air outlet 1027 respectively.

[0084] The transparent electrode 101 is made of epoxy resin or polycarbonate transparent material with a thickness of 5-30mm; the non-transparent electrode 102 is made of graphite material with a thickness of 1-5mm; the manifold 103 is made of metal material with a thickness of 1-5mm; the end plate 200 is formed by processing metal material with a thickness of 10-30mm; the height of the boss is equal to the sum of the thickness of the manifold 103 and the thickness of the non-transparent electrode 102; the depth of the transition channel 1041 is equal to the depth of the transparent channel 1013, the non-transparent channel 1022, the diverter 1042, and the confluence channel.

[0085] The assembly process is as follows:

[0086] (S1) Assembly of electrode assembly 100: Assemble the current collector 103 and the transparent electrode 101 with the transparent flow channel 1013 on one side, so that the current collector 103 matches the first sealing groove 1011. Then, install the non-transparent electrode 102 without the non-transparent flow channel 1022 on the top of the current collector 103 to ensure the matching of electrode cavity 1023 with transparent flow channel 1013, matching of second air inlet hole 1024 with first air inlet hole 1014, matching of second air outlet hole 1025 with first air outlet hole 1015, matching of fourth air inlet hole 1026 with third air inlet hole 1016, and matching of fourth air outlet hole 1027 with third air outlet hole 1017.

[0087] (S2) Assembly of electrode assembly 100 and membrane electrode 300: Connect each of the two contact surfaces of membrane electrode 300 to an electrode assembly 100, and connect the two contact surfaces of membrane electrode 300 to the non-transparent electrode assembly surface 1028, so that the first membrane electrode cavity 301, the second membrane electrode cavity 302, the third membrane electrode cavity 303 and the fourth membrane electrode cavity 304 are respectively matched with the second air inlet 1024, the second air outlet 1025, the fourth air inlet 1026 and the fourth air outlet 1027;

[0088] (S3) Assembly of electrode assembly 100, membrane electrode 300 and end plate 200: After step (S2) is completed, an end plate 200 is set on each side of the two transparent electrode plates 101 away from the non-transparent electrode plate 102, and the electrode assembly 100 and membrane electrode 300 are pressed and fixed by using screws through the screw holes 202 provided on the end plates 200.

[0089] During operation, after the reactant gas is introduced into each of the two inlets of the fuel cell, the fuel cell begins to work. An electrochemical reaction occurs on the cathode catalyst layer to generate water, which then passes through the cathode diffusion layer in gaseous or liquid form and reaches the cathode flow channel. Figure 1 After the transparent flow channel 1013 and the non-transparent flow channel 1022 in the electrode assembly 100 below the membrane electrode 300 are discharged, some water permeates through the membrane electrode 300 and eventually reaches the anode flow channel. Figure 1 The transparent flow channel 1013 and the non-transparent flow channel 1022 in the electrode assembly 100 above the membrane electrode 300 are discharged. The morphology and movement behavior of the liquid water in the transparent flow channel 1013 can be observed through the end plate 200 and the transparent electrode 101. In addition, a high-speed camera can be equipped to cooperate with the observable flow field fuel cell of this embodiment to acquire images of the fuel cell, extract liquid water distribution data in the flow channel, and then analyze the key factors affecting the water distribution of the fuel cell to formulate a reasonable fuel cell water management strategy.

[0090] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the interpretation of the present invention, without departing from the scope of the invention, should be within the protection scope of the present invention.

Claims

1. A fuel cell with observable flow field, characterized in that, It includes two end plates (200), two electrode assemblies (100) and a membrane electrode (300), wherein an electrode assembly (100) and an end plate (200) are respectively provided on two sides of the membrane electrode (300). The electrode assembly (100) includes a non-transparent electrode plate (102), a collector plate (103), and a transparent electrode plate (101). The collector plate (103) is disposed between the transparent electrode plate (101) and the non-transparent electrode plate (102). The side of the transparent electrode plate (101) closest to the collector plate (103) is a transparent electrode plate mounting surface (1018). The transparent electrode plate mounting surface (1018) is provided with a boss, a first air inlet hole (1014), and a first air outlet hole (1015). The boss is located in the middle of the transparent electrode plate mounting surface (1018) and has a transparent flow channel (1013). The first air inlet hole (1014) and the first air outlet hole (1015) are located on the boss. The transparent electrode plate (101) has two ends; the non-transparent electrode plate (102) has a non-transparent electrode plate mounting surface (1028) on the side away from the current collector plate (103). The non-transparent electrode plate mounting surface (1028) is provided with an electrode plate cavity (1023) that matches the boss, a non-transparent flow channel (1022), a second air inlet (1024) that matches the first air inlet (1014), and a second air outlet (1025) that matches the first air outlet (1015). The non-transparent flow channel (1022) is arranged around the electrode plate cavity (1023). The side of the non-transparent electrode plate (102) with the non-transparent flow channel (1022) is connected to the membrane electrode (300). The end plate (200) is provided with an end plate cavity (201) for observing the movement and distribution of liquid water in the flow channel of the electrode assembly (100) during the operation of the fuel cell stack; the end plate (200) presses and fixes the electrode assembly (100) and the membrane electrode (300) by screws; The collector plate (103) has a collector plate cavity (1031), and the size, number and position of the collector plate cavity (1031) are consistent with those of the electrode plate cavity (1023).

2. The observable flow field fuel cell according to claim 1, characterized in that, The transparent electrode assembly surface (1018) is also provided with a first sealing groove (1011) and a second sealing groove (1012). The first sealing groove (1011) is arranged around the boss, and the second sealing groove (1012) is arranged around the first sealing groove (1011), the first air inlet hole (1014) and the first air outlet hole (1015). A third sealing groove (1021) is also provided on the non-transparent electrode assembly surface (1028), which is arranged around the non-transparent flow channel (1022), the second air inlet hole (1024) and the second air outlet hole (1025).

3. The observable flow field fuel cell according to claim 2, characterized in that, The shape and size of the current collector (103) match the first sealing groove (1011). The current collector (103) is embedded in the first sealing groove (1011) and cooperates with the transparent electrode assembly surface (1018). The side of the current collector (103) away from the first sealing groove (1011) is flush with the transparent electrode assembly surface (1018).

4. The observable flow field fuel cell according to claim 3, characterized in that, The first sealing groove (1011) is bonded to the current collector (103) with glue; the second sealing groove (1012) is sealed to the non-transparent electrode plate (102) by the first sealing strip; the third sealing groove (1021) is sealed to the membrane electrode (300) by the second sealing strip.

5. The observable flow field fuel cell according to claim 4, characterized in that, The non-transparent flow channel (1022) is flat on the side near the collector plate (103) and fits against the transparent electrode mounting surface (1018); The top surface of the boss is flush with the non-transparent electrode assembly surface (1028). After assembly, the transparent flow channel (1013) and the non-transparent flow channel (1022) are connected to form a complete flow channel.

6. The observable flow field fuel cell according to claim 5, characterized in that, The end plate (200) is provided with several screw holes (202) around its perimeter. The screw passes through the screw holes (202) to press and fix the electrode assembly (100) and the membrane electrode (300).

7. The observable flow field fuel cell according to claim 1, characterized in that, A hydrophobic coating is provided on the boss.

8. The observable flow field fuel cell according to claim 1, characterized in that, The transparent electrode plate (101) is made of epoxy resin or polycarbonate transparent material with a thickness of 5-30 mm; the non-transparent electrode plate (102) is made of graphite material with a thickness of 1-5 mm; the current collector plate (103) is made of metal material with a thickness of 1-5 mm; and the end plate (200) is formed of metal material with a thickness of 10-30 mm.

9. The observable flow field fuel cell according to claim 1, characterized in that, The height of the boss is equal to the sum of the thickness of the current collector (103) and the thickness of the non-transparent electrode (102).

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