Bipolar plate of direct methanol fuel cell

Abstract

The utility model relates to a bipolar plate of a direct methanol fuel cell, which comprises a bipolar plate body, a cathode inlet and a cathode outlet are arranged on a cathode surface of the bipolar plate body, a plurality of cathode runners are arranged on the cathode surface of the bipolar plate body, one end of each cathode runner is communicated with the cathode inlet, and the other end of each cathode runner is communicated with the cathode outlet. The other end of each cathode flow channel is communicated with the cathode outlet, each cathode flow channel is of a snakelike structure, the anode surface of the bipolar plate body is provided with an anode inlet and an anode outlet, the anode surface of the bipolar plate body is provided with a plurality of anode flow channels, one end of each anode flow channel is communicated with the anode inlet, and the other end of each anode flow channel is communicated with the cathode outlet. And the other end of each anode runner is communicated with the anode outlet, and each anode runner is arranged in a snake-shaped structure. According to the bipolar plate, the current density in the plane of the bipolar plate is more uniform, the fuel conversion efficiency and the power density are improved, and the service lives of a membrane electrode and a galvanic pile are prolonged.

Description

Technical Field

[0001] The utility model relates to the field of fuel cells, in particular to a bipolar plate of a direct methanol fuel cell. Background Art

[0002] A direct methanol fuel cell (DMFC) is a low-temperature fuel cell using liquid methanol as fuel. It generates electricity through the electrochemical reaction between methanol and oxygen in the air, and simultaneously produces water and a small amount of carbon dioxide. It has the advantages of small size, clean environmental protection, easy storage and filling of fuel, long service life, etc.

[0003] The bipolar plate is an important component of a direct methanol fuel cell, playing important roles in distributing reactants, collecting current, water and heat management, mechanical support, and removing reaction by-products. The flow field structure of the bipolar plate is the most important feature of the bipolar plate, which will directly affect the performance, operating efficiency, and durability of the fuel cell.

[0004] After retrieval, the patent: A bipolar plate with a novel flow field structure (CN201711284139.3), specifically, it is a three-dimensional structure with an inclined slope, which uses the slope to increase the diffusion of gas in the battery to the MEA, promote mass transfer, and at the same time, is conducive to the discharge of the generated water in the MEA to increase the performance of the battery at high current density.

[0005] The existing bipolar plate flow field designs have varying degrees of deficiencies in aspects such as uneven flow field distribution, fluid pressure drop, drainage, and battery life. In addition, domestic and foreign scholars have also proposed biomimetic microchannel flow fields such as imitating tree crowns, leaf veins, and lung airways, which can provide reaction materials more evenly and drain water better. However, the biomimetic flow field is difficult to manufacture due to its overly complex structure and higher cost.

[0006] In view of the above defects, the designer actively conducts research and innovation in order to create a bipolar plate of a direct methanol fuel cell with a novel structure, making it more valuable for industrial use. Summary of the Utility Model

[0007] To solve the above technical problems, the purpose of the utility model is to provide a bipolar plate of a direct methanol fuel cell.

[0008] To achieve the above purpose, the utility model adopts the following technical solutions:

[0009] A bipolar plate for a direct methanol fuel cell includes a bipolar plate body. On the cathode surface of the bipolar plate body, a cathode inlet and a cathode outlet are provided. A number of cathode flow channels are formed on the cathode surface of the bipolar plate body. Each cathode flow channel is set as an independent cathode flow channel. One end of each cathode flow channel is communicated with the cathode inlet, and the other end of each cathode flow channel is communicated with the cathode outlet. The cathode flow channels are in a serpentine structure. On the anode surface of the bipolar plate body, an anode inlet and an anode outlet are provided. A number of anode flow channels are formed on the anode surface of the bipolar plate body. Each anode flow channel is an independent flow channel. One end of each anode flow channel is communicated with the anode inlet, and the other end of each anode flow channel is communicated with the anode outlet. Each anode flow channel is set in a serpentine structure.

[0010] Preferably, for the bipolar plate of a direct methanol fuel cell, the bipolar plate body is made of graphite.

[0011] Preferably, for the bipolar plate of a direct methanol fuel cell, there are 2 to 6 cathode flow channels.

[0012] Preferably, for the bipolar plate of a direct methanol fuel cell, there are 4 cathode flow channels.

[0013] Preferably, for the bipolar plate of a direct methanol fuel cell, there are 2 anode flow channels.

[0014] Preferably, for the bipolar plate of a direct methanol fuel cell, the widths of the cathode flow channels and the anode flow channels are between 1.5 mm and 2.0 mm.

[0015] Preferably, for the bipolar plate of a direct methanol fuel cell, the widths of the cathode flow channels and the anode flow channels are 1.9 mm.

[0016] Preferably, for the bipolar plate of a direct methanol fuel cell, the thickness of the bipolar plate body is 2.4 mm.

[0017] Preferably, for the bipolar plate of a direct methanol fuel cell, sealing grooves are formed at the peripheries of the cathode surface and the anode surface of the bipolar plate body, and sealing rings are connected in the sealing grooves.

[0018] By means of the above solution, the present utility model has at least the following advantages:

[0019] In the present utility model, a multi-channel cathode serpentine flow field and a two-channel anode serpentine flow field are respectively formed on the cathode and the anode of the bipolar plate, which can provide a more uniform supply of air and methanol aqueous solution, avoid the problem of insufficient fuel supply at the outlet of the bipolar plate, make the current density in the plane of the bipolar plate more uniform, and is beneficial to improving the fuel conversion efficiency, power density and the service life of the membrane electrode and the fuel cell stack.

[0020] The bipolar plate flow field structure of the present utility model has increased the fuel efficiency of the stack by 10 - 15%, the power density by 20% - 30%, and the durability performance by 30% compared with the single-channel serpentine flow field structure design.

[0021] The above description is only an overview of the technical solution of the present utility model. In order to better understand the technical means of the present utility model and implement it according to the content of the specification, the following is a detailed description of the preferred embodiments of the present utility model in conjunction with the accompanying drawings. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of the cathode surface of the present utility model;

[0024] Figure 2 It is a schematic structural diagram of the anode surface of the present utility model;

[0025] Figure 3 It is a schematic side structural diagram of the present utility model. Detailed Embodiments

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Usually, the components of the embodiments of the present application described and illustrated herein can be arranged and designed in various different configurations.

[0027] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the present application that is claimed, but merely represents the selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0028] Embodiment

[0029] Such as Figure 1 、 Figure 2 and Figure 3As shown in the figure, a bipolar plate of a direct methanol fuel cell includes a bipolar plate body 1. On the cathode surface of the bipolar plate body 1, a cathode inlet 2 and a cathode outlet 3 are provided. A number of cathode flow channels 4 are provided on the cathode surface of the bipolar plate body 1. Each cathode flow channel 4 is set as an independent cathode flow channel. One end of each cathode flow channel 4 is communicated with the cathode inlet 2, and the other end of each cathode flow channel 4 is communicated with the cathode outlet 3. The cathode flow channel 4 is in a serpentine structure. On the anode surface of the bipolar plate body 1, an anode inlet 5 and an anode outlet 6 are provided. A number of anode flow channels 7 are provided on the anode surface of the bipolar plate body 1. Each anode flow channel 7 is an independent flow channel. One end of each anode flow channel 7 is communicated with the anode inlet 5, and the other end of each anode flow channel 7 is communicated with the anode outlet 6. Each anode flow channel 7 is arranged in a serpentine structure.

[0030] In the present utility model, the bipolar plate body 1 is made of graphite.

[0031] In the present utility model, the number of the cathode flow channels 4 is 2 to 6, and there are 4 cathode flow channels 4 in the present utility model.

[0032] In the present utility model, the number of the anode flow channels is 2.

[0033] In the present utility model, the widths of the cathode flow channel 4 and the anode flow channel are 1.5 mm to 2.0 mm. Among them, the widths of the cathode flow channel 4 and the anode flow channel are 1.9 mm.

[0034] In the present utility model, the thickness of the bipolar plate body 1 is 2.4 mm.

[0035] Sealing grooves 8 are provided at the peripheries of the cathode surface and the anode surface of the bipolar plate body 1. Sealing rings are connected in the sealing grooves. Through the above design, the airtightness of the fuel cell stack can be improved, and the problems of poor airtightness or water leakage of the fuel cell stack can be avoided.

[0036] Air flows along a number of serpentine cathode flow channels at the cathode inlet. The design of a number of serpentine cathode flow channels is beneficial to providing a more uniform air supply;

[0037] Cathode flow field: The cathode flow channel provides the supply of air, and the reaction product is water.

[0038] Anode flow channel, the methanol aqueous solution flows along the anode flow channels (the first serpentine anode flow channel and the second serpentine anode flow channel) at the anode inlet to provide the supply of methanol. The design of the anode flow channel is beneficial to providing a more uniform methanol supply and avoiding the anode starvation phenomenon caused by insufficient methanol supply at the methanol outlet end.

[0039] Anode flow field: The anode flow channel provides the supply of methanol, and the reaction product is a small amount of carbon dioxide.

[0040] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship in which the product of this application is usually placed during use. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0042] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or vertical, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0044] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A bipolar plate for a direct methanol fuel cell, characterized in that: The invention comprises a bipolar plate body (1), wherein the cathode surface of the bipolar plate body (1) is provided with a cathode inlet (2) and a cathode outlet (3), and the cathode surface of the bipolar plate body (1) is provided with a plurality of cathode flow channels (4), each cathode flow channel (4) is arranged as an independent cathode flow channel, one end of each cathode flow channel (4) is connected to the cathode inlet (2), and the other end of each cathode flow channel (4) is connected to the cathode outlet (3), and the cathode flow channel (4) is in a serpentine structure; the anode surface of the bipolar plate body (1) is provided with an anode inlet (5) and an anode outlet (6), and the anode surface of the bipolar plate body (1) is provided with a plurality of anode flow channels (7), each anode flow channel (7) is an independent flow channel, one end of each anode flow channel (7) is connected to the anode inlet (5), and the other end of each anode flow channel (7) is connected to the anode outlet (6), and each anode flow channel (7) is arranged in a serpentine structure.

2. A bipolar plate for a direct methanol fuel cell according to claim 1, characterized in that: The bipolar plate body (1) is made of graphite.

3. The bipolar plate of a direct methanol fuel cell according to claim 1, characterized in that: The cathode flow channels (4) are provided with 2 to 6 channels.

4. A bipolar plate for a direct methanol fuel cell according to claim 3, characterized in that: There are four cathode flow channels (4).

5. The bipolar plate of a direct methanol fuel cell according to claim 1, characterized in that: The anode flow channels are provided with two.

6. The bipolar plate of a direct methanol fuel cell according to claim 1, characterized in that: The width of the cathode flow channel (4) and the anode flow channel is between 1.5 mm and 2.0 mm.

7. A bipolar plate for a direct methanol fuel cell according to claim 6, characterized in that: The width of the cathode flow channel (4) and the anode flow channel is 1.9 mm.

8. A bipolar plate for a direct methanol fuel cell according to claim 1 or 2, characterized in that: The thickness of the bipolar plate body (1) is 2.4 mm.

9. The bipolar plate of a direct methanol fuel cell according to claim 1, characterized in that: Sealing grooves are provided at the peripheries of the cathode surface and the anode surface of the bipolar plate body (1), and sealing rings are connected in the sealing grooves.

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