Cathode plate, fuel cell, and vehicle

Abstract

This invention provides a cathode plate, a fuel cell, and a vehicle. The cathode plate is used in a proton exchange membrane fuel cell. The cathode plate includes a separator and a flow field plate. One side of the separator is attached to the anode plate of the fuel cell, and the flow field plate is attached to the other side of the separator. The side of the flow field plate facing the separator has a plurality of uniformly spaced, protruding scale walls that face the separator. The scale walls and the flow field plate form a main flow channel unit. The spacers between adjacent main flow channel units and the separator form an intermediate flow channel unit. Fluid on the side of the flow field plate facing the separator can flow in the main flow channel unit and the intermediate flow channel unit.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and more specifically, to a cathode plate, a fuel cell, and a vehicle including the fuel cell. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that converts the chemical energy of fuel into electrical energy through a chemical reaction. As one of the core components of a fuel cell, the bipolar plates (cathode and anode plates) have functions such as supporting and fixing the fuel, isolating and evenly distributing the reaction medium and coolant, collecting and discharging current, and connecting individual cells in series. The bipolar plate materials for PEMFCs are mainly metals, graphite, and composite materials, with metal bipolar plates representing the current development trend.

[0003] Traditional PEMFCs typically employ a long, narrow flow channel design for their bipolar plates. Inside a PEMFC, chemical reactions continue to occur as the gas flow advances, and the water produced in these reactions must continue to move forward with the gas flow to be expelled, thus increasing the water content. Due to the combined effects of factors such as the hydrophilic / hydrophobic properties of the materials, airflow scouring, water surface tension, water distribution in the gas flow, and cooling arrangements, moisture in the gas flow is prone to condensation and accumulation, clogging the gas flow channels.

[0004] Metal bipolar plates are manufactured using a stamping process. Due to limitations in metal materials and manufacturing processes, the grooves in the flow field of metal bipolar plates are generally not very deep. Consequently, the gas flow channels are shallower and the flow resistance is greater, which increases the difficulty of distributing the reaction medium in the flow field and the system energy consumption. Furthermore, water is more likely to condense and accumulate, which may lead to problems such as increased catalyst usage, increased overall cost, reduced volumetric power density, and decreased efficiency in fuel cells. Summary of the Invention

[0005] One aspect of the technical problem to be solved by the present invention is how to prevent uneven distribution of the reaction medium in the metal bipolar plate and the condensation and accumulation of water generated in the gas flow channel.

[0006] Furthermore, other aspects of the present invention are also intended to solve or alleviate other technical problems existing in the prior art.

[0007] The present invention provides a cathode plate, a fuel cell, and a vehicle. Specifically, according to one aspect of the present invention, the following is provided:

[0008] A cathode plate for a proton exchange membrane fuel cell, wherein the cathode plate includes a separator and a flow field plate, one side of the separator is attached to the anode plate of the fuel cell, and the flow field plate is attached to the other side of the separator. The side of the flow field plate facing the separator has a plurality of scale walls that protrude toward the separator and are evenly spaced from each other. The scale walls and the flow field plate form a main flow channel unit. The spacers between adjacent main flow channel units and the separator form an intermediate flow channel unit. Fluid on the side of the flow field plate facing the separator can flow in the main flow channel unit and the intermediate flow channel unit.

[0009] Optionally, according to one embodiment of the present invention, the main channel unit has an inflow end and an outflow end in the flow direction, and in the flow direction of the fluid on the flow field plate, the cross-sectional area of ​​the inflow end of the main channel unit is larger than the cross-sectional area of ​​the outflow end, and the intermediate channel unit also has an inflow end and an outflow end in the flow direction accordingly.

[0010] Optionally, according to one embodiment of the present invention, the flow field plate has multiple rows of parallel main channel units, with adjacent rows of main channel units arranged alternately, such that the inflow end of a single main channel unit is connected to the outflow ends of two main channel units in its upstream adjacent row and the outflow end of an intermediate flow channel unit between the two main channel units, and the outflow end of the single main channel unit is connected to the inflow ends of two main channel units in its downstream adjacent row and the inflow end of an intermediate flow channel unit between the two main channel units.

[0011] Optionally, according to one embodiment of the present invention, the outflow end of the single main channel unit includes a first outflow portion and two second outflow portions, the first outflow portion being connected to the inflow end of the intermediate channel unit between the two main channel units in the downstream adjacent row, and the two second outflow portions being connected to the inflow ends of the two main channel units in the downstream adjacent row, respectively.

[0012] Optionally, according to one embodiment of the invention, the scale wall of the main channel unit is inclined toward the partition in the opposite direction to the flow direction.

[0013] According to another aspect of the present invention, a fuel cell is provided, comprising a membrane electrode assembly, an anode plate and a cathode plate as described above, wherein one side of the anode plate is attached to the anode side of the membrane electrode assembly and the other side is attached to the separator, and the flow field plate is arranged on the cathode side of the membrane electrode assembly.

[0014] Alternatively, according to another embodiment of the present invention, a plurality of strip-shaped channel walls perpendicular to the flow direction of the fluid on the cathode plate and opposite to the protrusion of the partition are constructed on the anode plate, and the strip-shaped channel walls and the partition form a cooling fluid channel.

[0015] Alternatively, according to another embodiment of the present invention, the fuel cell is a hydrogen-oxygen fuel cell.

[0016] According to another aspect of the present invention, a vehicle is provided, wherein the above-described fuel cell is included.

[0017] The advantages of this invention include:

[0018] 1. A scale-like biomimetic structure is set on the flow field plate, so that the gas at the flow field plate is continuously split and merged based on the staggered arrangement of the main flow channel unit and the intermediate flow channel unit. In this way, the gas is uniformly mixed under the action of the flow field, providing an orderly and controllable fuel supply for the chemical reaction at the cathode plate, and continuously carrying away the water and heat generated by the reaction, realizing the redistribution of reaction medium, water and heat; and due to the scouring effect of the airflow, water is difficult to condense and accumulate in the flow channel unit, thus ensuring the effective chemical reaction area of ​​the membrane electrode.

[0019] 2. The intermediate flow channel unit is open to the partition, which is conducive to the airflow blowing water vapor to the partition with a lower temperature, and cooling it into liquid water at the partition, and then expelling it from the cathode plate with the airflow, further promoting the discharge of the water generated by the reaction. Attached Figure Description

[0020] Referring to the accompanying drawings, the above and other features of the present invention will become apparent, wherein,

[0021] Figure 1 A partial structural schematic diagram of the flow field plate of the cathode plate according to an embodiment of the present invention is shown;

[0022] Figure 2 A schematic cross-sectional view of the main channel unit of a flow field plate according to an embodiment of the present invention is shown;

[0023] Figure 3 A partial structural schematic diagram of a fuel cell according to an embodiment of the present invention is shown. Detailed Implementation

[0024] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0025] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive. Furthermore, the terms "first," "second," "third," and similar expressions are used for descriptive and distinguishing purposes only and should not be construed as indicating or implying the relative importance of the corresponding components.

[0026] The cathode plate of the present invention is generally used in proton exchange membrane fuel cells, such as hydrogen-oxygen fuel cells employing proton exchange membranes. The cathode plate 100 includes a separator 1 and a flow field plate 2, and is attached to the anode plate 200 via one side of the separator 1. The flow field plate 2 is attached to the other side of the separator 1.

[0027] refer to Figure 1 This diagram illustrates a partial structural schematic of the flow field plate of a cathode plate according to an embodiment of the present invention. To facilitate the redistribution of the reaction medium, water, and heat on the flow field plate 2, the flow field plate 2 of the present invention employs a scale-like biomimetic structural design. On the side of the flow field plate 2 facing the partition 1, a plurality of scale walls 21 protruding towards the partition 1 and evenly spaced from each other are constructed. It should be understood that the term "scale" as used in this invention refers to a structure resembling fish scales, with at least one edge fixed to the flow field plate 2, arranged in a layered and staggered manner. Figure 1 In this embodiment, one side of a single scale wall 21 is arc-shaped, while the other three sides are in the shape of an inverted trapezoid and are all fixed to the flow field plate 2. The two corners formed by these three sides are below the other scale walls. The scale wall 21 arches within the flow field plate 2 (in...). Figure 1 The scale wall 21 (which arches upwards from the paper) extends obliquely from its edge on the partition 1 towards its arc-shaped edge, opposite to the flow direction of the fluid on the flow field plate 2. In other words, the scale wall 21 is obliquely inclined towards the partition 1, opposite to the flow direction of the fluid on the flow field plate 2. That is, the scale wall 21 is obliquely inclined towards the partition 1 and forms a main flow channel unit 22 with the flow field plate 2. Fluid on the side of the flow field plate 2 facing the partition 1 can flow in the main flow channel unit 22.

[0028] Since the scale walls 21 are spaced apart from each other, a flow channel through which fluid can flow is also formed between adjacent scale walls 21 and partitions 1, that is, between adjacent main flow channel units and partitions 1. This channel is defined here as an intermediate flow channel unit 23. Fluid flowing on the flow field plate 2 can also flow in the intermediate flow channel unit 23.

[0029] refer to Figure 2 This diagram shows a cross-sectional schematic of a main channel unit of a flow field plate according to an embodiment of the present invention. The main channel unit 22 has an inlet end 221 and an outlet end 222 in the direction of fluid flow on the flow field plate 2. Due to the inclined orientation of the scale wall 21, the cross-sectional area of ​​the inlet end 221 of the main channel unit 22 is larger than the cross-sectional area of ​​the outlet end 222 in the direction of fluid flow on the flow field plate 2. By making the flow cross-section of the inlet end 221 larger than that of the outlet end 222, the flow velocity of the fluid flowing out of the main channel unit 22 can be made greater than the flow velocity of the fluid flowing into the main channel unit 22, thereby increasing the gas flow velocity flowing out of the main channel unit 22. This allows for better control of water accumulated in the main channel unit 22, especially water accumulated at the side edges of the main channel unit 22 (e.g., in…). Figure 2 (As shown by reference numeral 10 in the attached figure) It is carried out from the main flow channel unit 22. The intermediate flow channel unit 23 also has an inlet end 231 and an outlet end 232 in the direction of fluid flow.

[0030] Refer again Figure 1 The flow field plate 2 has multiple rows of parallel main channel elements. Here, we take... Figure 1 Taking a single main channel unit 22 as an example, adjacent rows of main channel units are arranged in an alternating manner, such that the inflow end 221 of a single main channel unit 22 is connected to the outflow ends of two main channel units a and b in its upstream adjacent row, as well as the outflow end of the intermediate channel unit c between these two main channel units a and b. Furthermore, the outflow end of this single main channel unit 22 is connected to the inflow ends of two main channel units d and e in its downstream adjacent row, as well as the inflow end of the intermediate channel unit 23 between these two main channel units d and e. In other words, when fluid flows into and out of the main channel unit 22, the fluid will be divided into three streams (see...). Figure 1The gas flows into the downstream intermediate flow channel unit 23 and its two adjacent main flow channel units d and e, respectively. In other words, part of the gas flow from the intermediate flow channel unit c and its two adjacent main flow channel units a and b will also flow into a downstream main flow channel unit 22. Through this continuous diversion and merging, the gas flow at the flow field plate 2 continuously changes its velocity and direction, and is mixed evenly under the action of the flow field. This provides an orderly and controllable fuel supply for the chemical reaction at the cathode plate 100, and continuously removes the water and heat generated by the reaction, realizing the redistribution of the reaction medium, water, and heat. Furthermore, due to the scouring effect of the airflow, the water 10 in the flow field plate 2 is carried away, preventing it from accumulating in the flow field plate 2, especially at the side edges of the main flow channel unit 22.

[0031] Refer again Figure 2 The outflow end 222 of the main channel unit 22 includes a first outflow section 223 and two second outflow sections 224. The first outflow section 223 is connected to the inflow end of the intermediate channel unit 23 between two adjacent main channel units d and e downstream. The two second outflow sections 224 are respectively connected to the inflow ends of two adjacent main channel units d and e downstream. The way the outflow end 222 is divided into three outflow sections 223 and 224 better realizes the flow mode of diverting from the main channel unit 22 to the downstream intermediate channel unit 23 and the main channel units d and e on both sides. The sum of the cross-sectional areas of the first outflow section 223 and the two second outflow sections 224 along the flow direction of the fluid is less than the cross-sectional area of ​​the inflow end 222 along the flow direction of the fluid.

[0032] Another aspect of the present invention provides a fuel cell. (See reference...) Figure 3 This diagram illustrates a partial structural schematic of a fuel cell according to an embodiment of the present invention. The fuel cell 1000 is, for example, a hydrogen-oxygen fuel cell, and includes a membrane electrode assembly (MEA) 300, an anode plate 200, and the aforementioned cathode plate 100. The MEA 300 includes a cathode side 301 and an anode side 302. One side of the anode plate 200 is attached to the anode side 302 of the MEA 300, and the other side is attached to the separator 1 of the cathode plate 100. The flow field plate 2 of the cathode plate 100 is arranged on the cathode side 301 of the MEA 300.

[0033] In another embodiment of the invention, a plurality of strip-shaped channel walls 201, perpendicular to the flow direction of the fluid on the cathode plate 100 and opposite to the protrusion of the partition 1, are constructed on the anode plate 200. These strip-shaped channel walls 201 are arranged parallel to each other and evenly spaced apart. The strip-shaped channel walls 201 and the partition 1 form a cooling fluid channel 400. Cooling fluid, especially water, is introduced into these cooling fluid channels 400 for cooling the fluid at the cathode plate 100.

[0034] Because the baffle 1 is constructed as a flat plate, and the cooling fluid is located above the baffle 1, the water vapor generated at the flow field plate 2 of the cathode plate 100 can be cooled into liquid water on the baffle 1. Through the biomimetic scale structure design of the flow field plate 2, especially the design of the intermediate flow channel unit surrounded by the baffle 1, the airflow can more easily blow the water vapor onto the cooled baffle 1, thereby causing the water vapor to liquefy on the baffle 1. This also facilitates the airflow to further discharge the formed liquid water from the cathode plate 100.

[0035] Another aspect of the present invention provides a vehicle comprising the aforementioned fuel cell 1000.

[0036] It should be understood that the fuel cell of the present invention can be installed in various vehicles, including cars, trucks, buses, etc. Therefore, the subject matter of the present invention also aims to protect various vehicles equipped with the fuel cell of the present invention.

[0037] It should be understood that all the above preferred embodiments are exemplary and not restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of the present invention should be within the legal protection scope of the present invention.

Claims

1. A cathode plate for use in a proton exchange membrane fuel cell, characterized in that, The cathode plate includes a partition and a flow field plate. One side of the partition is attached to the anode plate of the fuel cell, and the flow field plate is attached to the other side of the partition. The side of the flow field plate facing the partition has a plurality of scale walls that protrude toward the partition and are evenly spaced from each other. The scale walls and the flow field plate form a main flow channel unit. The spacer between adjacent main flow channel units and the partition form an intermediate flow channel unit. Fluid on the side of the flow field plate facing the partition can flow in the main flow channel unit and the intermediate flow channel unit. One side of a single scale wall is arc-shaped, while the other three sides are inverted trapezoidal and fixed to the flow field plate, so that the single scale wall forms a cantilever cavity with three sides fixed and one side free, and the two corners formed by these three sides are below the other scale walls. The main channel unit has an inflow end and an outflow end in the flow direction. In the flow direction of the fluid on the flow field plate, the cross-sectional area of ​​the inflow end of the main channel unit is larger than the cross-sectional area of ​​the outflow end. The intermediate channel unit also has an inflow end and an outflow end in the flow direction accordingly. The flow field plate has multiple rows of parallel main channel units, with adjacent rows of main channel units arranged in an alternating manner, such that the inflow end of a single main channel unit is connected to the outflow ends of two main channel units in its upstream adjacent row and the outflow end of the intermediate flow channel unit between these two main channel units, and the outflow end of a single main channel unit is connected to the inflow ends of two main channel units in its downstream adjacent row and the inflow end of the intermediate flow channel unit between these two main channel units. The outflow end of the single main channel unit includes a first outflow section and two second outflow sections. The first outflow section is connected to the inflow end of the intermediate channel unit between the two main channel units in the downstream adjacent row, and the two second outflow sections are respectively connected to the inflow ends of the two main channel units in the downstream adjacent row.

2. The cathode plate according to claim 1, characterized in that, The scale walls of the main flow channel unit are inclined toward the partition in the opposite direction to the flow direction.

3. A fuel cell, characterized in that, It includes a membrane electrode, an anode plate, and a cathode plate according to any one of claims 1 to 2, wherein one side of the anode plate is attached to the anode side of the membrane electrode and the other side is attached to the partition plate, and the flow field plate is arranged on the cathode side of the membrane electrode.

4. The fuel cell according to claim 3, characterized in that, The anode plate has multiple strip-shaped channel walls that are perpendicular to the flow direction of the fluid on the cathode plate and opposite to the protrusion of the partition plate. The strip-shaped channel walls and the partition plate form a cooling fluid channel.

5. The fuel cell according to claim 3, characterized in that, The fuel cell is a hydrogen-oxygen fuel cell.

6. A vehicle, characterized in that, The fuel cell includes any one of claims 3 to 5.

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