Fuel cell plate and fuel cell

Abstract

The present invention discloses a fuel cell plate and a fuel cell. The fuel cell plate includes a plate body, and the plate body is provided with a plurality of reaction channels and a plurality of cooling channels. The reaction channels have narrow inlets and outlets and wide channels, and the cooling channels have wide inlets and outlets and narrow channels. The reaction channels with the above structure have a greater length than straight reaction channels, and thus have a larger reaction area. The airflow can have a higher reaction rate when flowing through the reaction channels, thereby increasing the power of the fuel cell. The cooling channels with the above structure can compress the airflow passing through, increase the flow rate, and the cooling airflow with a higher flow rate can bring a better cooling effect, thereby improving the cooling effect of the fuel cell. Therefore, the fuel cell plate of the present invention has the advantages of high reaction power and good cooling effect, and also has the advantages of simple structure, convenient manufacturing and low cost.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to a fuel cell polar plate and a fuel cell. Background Art

[0002] At present, one of the key materials widely used in proton exchange membrane fuel cells is the proton exchange membrane based on perfluorosulfonic acid membrane. The membrane material needs to exert the characteristics of proton conduction in the presence of water, and its optimal operating temperature is 70-90°C, so thermal management is required for proton exchange membrane fuel cells. A large amount of heat is generated during battery operation. When the system temperature is too high, the power generation efficiency is reduced and the service life is shortened, so the temperature of the entire system needs to be controlled.

[0003] For air-cooled fuel cell stacks, heat is generally dissipated by designing the bipolar plate flow channel on the cathode side. Since the air entering the cathode side of the air-cooled stack with an open cathode is directly connected to the outside world without any pressurization, its actual power generation is directly proportional to the contact area between the cathode side GDL and the air, so the design of the cathode side bipolar plate needs to take into account the size of the contact area. In addition, the material of the bipolar plate needs to be considered, which directly affects the quality and performance of the entire stack.

[0004] Chinese invention patent CN213483783 U adopts a conventional rectangular channel, and adjusts the reaction air volume and cooling air volume by controlling the ratio of the channel height and width, so as to obtain the ideal power. However, this structure cannot take into account both the reaction air volume and the cooling air volume at the same time, and it is difficult to adjust to the best working state.

[0005] Chinese invention patent CN 208507830 controls the temperature of the fuel cell stack by adding an arc-shaped induced draft fan at the top inlet of the fuel cell stack to increase the air volume. Although this design can control the temperature and improve the performance of the fuel cell stack to a certain extent, it is contrary to the design requirements of the air-cooled stack. The addition of too many external designs will increase the size of the fuel cell stack and make it inconvenient to use.

[0006] Chinese invention patent CN112968191 A adds an open baffle at the end of the cathode reaction gas channel in patent CN213483783 U, thereby reducing the air flow rate of the reaction channel and increasing the air flow rate of the cooling channel to control the temperature of the entire stack. However, this method reduces the reaction rate and leads to a decrease in overall power. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the defects of low overall power and large volume in the prior art and to provide a fuel cell plate and a fuel cell.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] A fuel cell plate comprises a plate body, on which a plurality of reaction channels and a plurality of cooling channels are arranged. The reaction channels have narrow inlets and outlets and wide channels, while the cooling channels have wide inlets and outlets and narrow channels.

[0010] Compared with a straight reaction channel, the reaction channel of the above structure has a larger side wall length, thereby having a larger reaction area. When the airflow flows through the reaction channel, it can have a higher reaction rate, thereby increasing the power of the fuel cell.

[0011] When the airflow flows through the cooling flow channel of the above structure, the airflow is compressed and the flow rate increases. The cooling airflow with a higher flow rate can bring a better cooling effect, thereby improving the cooling effect of the fuel cell.

[0012] Therefore, the fuel cell plate of the present invention has the advantages of high reaction power and good cooling effect, and also has the advantages of simple structure, convenient manufacturing and low cost.

[0013] Preferably, the cross section of the electrode plate body perpendicular to the reaction channel and the cooling channel is wavy, the reaction channel and the cooling channel are respectively located in depressions on different surfaces of the electrode plate body, and the cross section is preferably square-wave shaped.

[0014] Placing the cooling channel and the reaction channel on the front and back sides of the plate body can facilitate the layout of the gas path and the flow path, making the overall layout of the fuel cell more concise and compact. At the same time, the use of this structure enables the fuel cell plate to be formed in one go by stamping, which is convenient for processing and production. The use of a square wave plate body can further increase the reaction area of ​​the reaction channel and the cooling channel, improve the reaction power of the reaction channel and the cooling efficiency of the cooling channel.

[0015] Preferably, the width of the inlet and outlet ends of the reaction channel is 0.4-0.6 mm, and the width of the widest part of the channel is 1.9-2.1 mm.

[0016] Preferably, the width of the inlet and outlet ends of the cooling channel is 1.9-2.1 mm, and the width of the narrowest part of the channel is 0.4-0.6 mm.

[0017] Thereby, the reaction channel and the cooling channel can be interlocked with each other, and the structure is more compact.

[0018] Preferably, the width of the inlet and outlet ends of the reaction channel is 0.4-0.6 mm, and the width of the widest part of the channel is 2.3-2.7 mm.

[0019] Preferably, the width of the inlet and outlet ends of the cooling channel is 2.3-2.7 mm, and the width of the narrowest part of the channel is 0.4-0.6 mm.

[0020] Likewise, the reaction channel and the cooling channel can be interlocked with each other, resulting in a more compact structure.

[0021] Preferably, the length of the electrode body along the extension direction of the cooling channel and the reaction channel is 1-2 cm, the length along the direction perpendicular to the extension direction of the cooling channel and the reaction channel is 2-3 cm, and the thickness is 0.07-0.13 mm.

[0022] Preferably, the plate body is made of titanium alloy or stainless steel.

[0023] Preferably, the surface of the electrode body has a gold-plated layer.

[0024] The present invention also provides a fuel cell, characterized in that it comprises the fuel cell plate as described above.

[0025] The positive improvement effect of the present invention is that it enables the electrode plate of the fuel cell to take into account both cooling efficiency and reaction rate, while having the advantages of simple structure and compact size. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a three-dimensional diagram of the fuel cell plate;

[0027] Figure 2 is a top view of the fuel cell plate;

[0028] Figure 3 is a side view of the fuel cell plate;

[0029] Description of reference numerals:

[0030] Plate body 100

[0031] Reaction channel 200

[0032] Cooling channel 300 DETAILED DESCRIPTION

[0033] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0034] Example 1

[0035] like Figure 1 , Figure 2 and Figure 3As shown, a fuel cell plate includes a plate body 100, which is a metal plate or a metal sheet. A plurality of reaction channels 200 and a plurality of cooling channels 300 are provided on the plate body 100. The extension directions of the reaction channels 200 and the cooling channels 300 are parallel to each other. The reaction channels 200 are in a shape with a narrow inlet and outlet and a wide channel, and the cooling channels 300 are in a shape with a wide inlet and outlet and a narrow channel.

[0036] Specifically in this embodiment, the width of the reaction channel 200 gradually widens from the inlet toward the middle of the channel, and then gradually narrows from the middle of the channel to the outlet, so that the side walls of the reaction channel 200 present an outward convex arc shape.

[0037] The reaction channel 200 of the present invention adopts the above structure and has a longer side wall length compared to the traditional straight reaction channel. This also means that when the airflow flows through the reaction channel 200 of the present invention, it can contact a larger area of ​​the electrode plate, the reaction is more complete, and the reaction rate is higher, thereby improving the efficiency of the fuel cell.

[0038] Specifically in this embodiment, the width of the cooling channel 300 gradually narrows from the inlet toward the middle of the channel, and then gradually widens from the middle of the channel to the outlet, thereby making the side walls of the reaction channel 200 present an inwardly concave arc shape.

[0039] By adopting the above structure, the air is compressed when flowing through the cooling channel 300, thereby increasing the flow rate, taking away the heat generated by the fuel cell reaction more quickly, and reducing the temperature of the fuel cell. In addition, the concave arc side wall of the cooling channel 300 is longer and has a larger contact area than the straight side wall of the conventional channel. The larger contact area means that the cooling airflow can exchange heat more fully, further improving the cooling efficiency.

[0040] Therefore, the fuel cell plate of the present invention has the advantages of high reaction power and good cooling effect, and also has the advantages of simple structure, convenient manufacturing and low cost.

[0041] In this embodiment, the inlet and outlet widths of the reaction channel 200 are consistent, and the widest part of the reaction channel 200 corresponds to the midpoint of the reaction channel 200; the inlet and outlet widths of the cooling channel 300 are also consistent, and the narrowest part of the cooling channel 300 corresponds to the midpoint of the cooling channel 300. In other words, the reaction channel 200 and the cooling channel 300 are both centrally symmetrical. Therefore, the inlet and outlet of the reaction channel 200 and the cooling channel 300 can be interchanged with each other. Such a design can improve the fault tolerance rate during fuel cell assembly, improve assembly efficiency, and thus improve the yield rate and production speed.

[0042] In this embodiment, the reaction channel 200 and the cooling channel 300 are alternately arranged on the electrode body 100. And the reaction channel 200 and the cooling channel 300 are arranged in an interlocking manner. The interlocking arrangement referred to here means that the protruding portion of the reaction channel 200 is exactly placed in the space reserved by the inward recessed portion of the cooling channel 300. In this way, the reaction channel 200 and the cooling channel 300 can be arranged more closely, thereby improving the space utilization rate. In addition, the reaction channel 200 and the cooling channel 300 are arranged in close proximity, so that the cooling channel 300 can take away the heat from the reaction channel 200 faster and more efficiently, thereby further improving the cooling effect.

[0043] It should be further explained here that the reaction channel 200 and the cooling channel 300 can be located on the same side of the fuel cell plate, or can be separately arranged on the front and back sides of the fuel cell plate. The present invention preferably arranges the reaction channel 200 and the cooling channel 300 on the front and back sides of the fuel cell plate. With such a structure, on the one hand, more reaction channels 200 and cooling channels 300 can be added to improve the area utilization of the fuel cell plate. On the other hand, it is convenient to arrange the reaction pipeline and cooling pipeline in the fuel cell, which is conducive to optimizing the overall layout of the fuel cell, reducing the difficulty of design and manufacturing, and at the same time helping to reduce the volume of the fuel cell.

[0044] The present invention realizes that the reaction channel 200 and the cooling channel 300 are alternately arranged on the front and back sides of the plate body 100 in the following manner: the cross-section of the plate body 100 perpendicular to the reaction channel 200 and the cooling channel 300 is wavy, and the reaction channel 200 and the cooling channel 300 are respectively located in depressions on different surfaces of the plate body. The depression referred to here refers to the position on the surface of one side of the plate body 100 corresponding to the trough. The use of such a structure allows the cooling channel 300 and the reaction channel 200 to be alternately arranged on the front and back sides of the plate body 100, which is convenient for the layout of the gas path and the flow path, and can make the overall layout of the fuel cell more concise and compact. At the same time, the use of this structure allows the fuel cell plate to be formed in one go by stamping, which is convenient for processing and production.

[0045] Preferably, the cross-section of the electrode body 100 perpendicular to the reaction channel 200 and the cooling channel 300 is square wave-shaped. Compared with the sinusoidal waveform, the cross-sectional length of the square wave is longer. Therefore, the use of a square wave-shaped electrode body can further increase the reaction area of ​​the reaction channel 200 and the cooling channel 300, improve the reaction power of the reaction channel and the cooling efficiency of the cooling channel 300.

[0046] In this embodiment, the width of the inlet and outlet of the reaction channel 200 is 0.4-0.6 mm, and the width of the widest part of the reaction channel is 1.9-2.1 mm. The width of the inlet and outlet of the cooling channel is 1.9-2.1 mm, and the width of the narrowest part of the cooling channel is 0.4-0.6 mm. In this way, the reaction channel 200 and the cooling channel 300 can be interlocked with each other, and the structure is more compact.

[0047] In this embodiment, the length of the plate body 100 along the extension direction of the cooling channel 300 and the reaction channel 200 (i.e., the length of the cooling channel 300 and the reaction channel 200) is 1-2 cm, the length along the direction perpendicular to the extension direction of the cooling channel 300 and the reaction channel 200 is 2-3 cm, and the thickness is 0.07-0.13 mm. The plate body 100 is made of stainless steel and has a gold-plated layer on the surface to reduce its contact resistance with the GDL and improve its own conductivity.

[0048] Table 1 shows the reaction temperature and reaction rate of the plate bodies with different sizes of reaction channels and cooling channels in this embodiment. The reaction rate benchmark is as follows: the reaction rate of the fuel cell plate with the same number of reaction channels 200 and cooling channels 300, the same area of ​​the plate body 100 and the straight groove wall is 100%.

[0049]

[0050] Combined with the data in Table 1, it can be seen that in this embodiment, the larger the inlet and outlet widths and the widest width of the reaction channel 200, the larger the inlet and outlet widths and the widest width of the cooling channel 300, the larger the contact area and the higher the reaction efficiency, but as the size of the reaction channel 200 and the cooling channel 300 increases, the plate size also needs to increase accordingly, which leads to an increase in the overall volume of the fuel cell plate. This is not conducive to volume control, so specifically in this embodiment, the inlet and outlet widths of the reaction channel 200 are 0.5mm, the widest width in the middle is 2mm, the inlet and outlet widths of the cooling channel are 2mm, and the narrowest width in the middle is 0.5mm.

[0051] Example 2

[0052] The main difference between this embodiment and the embodiment 1 is that the material of the electrode body 100 is replaced by gold-plated titanium alloy instead of gold-plated stainless steel. The reaction temperature and reaction rate are specifically shown in Table 2:

[0053] Table 2

[0054] Combined with Table 2, it can be seen that the reaction efficiency of the fuel cell plate made of gold-plated titanium alloy is lower than that of the fuel cell plate made of gold-plated stainless steel, and the reaction temperature is higher. This is because the thermal conductivity of titanium alloy is lower than that of stainless steel, but titanium alloy has the advantage of being lighter than stainless steel. The use of titanium alloy plates can greatly reduce the weight of the fuel cell.

[0055] Specifically in this embodiment, for the convenience of production, the inlet and outlet widths of the reaction channel 200 are 0.5 mm, and the widest width in the middle is 2 mm. The inlet and outlet widths of the cooling channel are 2 mm, and the narrowest width in the middle is 0.5 mm.

[0056] Example 3

[0057] Compared with Example 1, the main difference of this embodiment is the size of the reaction channel 200 and the cooling channel 300. The specific size data, reaction temperature and reaction rate data are shown in Table 3:

[0058] Table 3

[0059] It can be seen that compared with Example 1, as the ratio of the inlet and outlet width of the cooling channel 300 to the width of the narrowest part of the cooling channel 300 increases, and the ratio of the inlet and outlet width of the reaction channel 200 to the width of the widest part of the reaction channel decreases, the reaction rate and cooling effect increase accordingly. Since a higher reaction rate means greater heat generation, although the cooling effect is also improved, the overall reaction temperature remains unchanged. Based on the consideration of ease of production, in this embodiment, the inlet and outlet width of the reaction channel 200 is 0.5mm, and the width of the widest part in the middle is 2.5mm. The inlet and outlet width of the cooling channel is 2.5mm, and the width of the narrowest part in the middle is 0.5mm.

[0060] The present invention also provides a fuel cell, comprising the fuel cell plate as described above. The fuel cell has the advantages of high reaction efficiency and good cooling effect.

[0061] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A fuel cell plate, comprising a plate body, wherein the plate body is provided with a plurality of reaction channels and a plurality of cooling channels, wherein: The inlet and outlet of the reaction flow channel are narrow, and the flow channel is wide, and the inlet and outlet of the cooling flow channel are wide, and the flow channel is narrow; The width of the reaction channel gradually widens from the inlet toward the middle of the channel, and then gradually narrows from the middle of the channel to the outlet, so that the side walls of the reaction channel are convex arc-shaped; The width of the cooling channel gradually narrows from the inlet toward the middle of the channel, and then gradually widens from the middle of the channel to the outlet, so that the side walls of the cooling channel are in a concave arc shape; The reaction channel and the cooling channel are respectively located in depressions on different surfaces of the electrode plate body.

2. The fuel cell plate according to claim 1, characterized in that: The cross section of the electrode plate body perpendicular to the reaction flow channel and the cooling flow channel is wavy.

3. The fuel cell plate according to claim 2, characterized in that: The cross section is square wave shaped.

4. The fuel cell plate according to claim 1, characterized in that: The width of the inlet and outlet ends of the reaction channel is 0.4-0.6 mm, and the width of the widest part of the channel is 1.9-2.1 mm.

5. The fuel cell plate according to claim 1, characterized in that: The width of the inlet and outlet ends of the reaction channel is 0.4-0.6 mm, and the width of the widest part of the channel is 2.3-2.7 mm.

6. The fuel cell plate according to claim 1, characterized in that: The width of the cooling channel inlet and outlet is 1.9-2.1 mm, and the width of the narrowest part of the channel is 0.4-0.6 mm.

7. The fuel cell plate according to claim 1, characterized in that: The width of the cooling channel inlet and outlet is 2.3-2.7 mm, and the width of the narrowest part of the channel is 0.4-0.6 mm.

8. The fuel cell plate according to any one of claims 1 to 7, characterized in that: The length of the electrode body along the extending direction of the cooling flow channel and the reaction flow channel is 1-2 cm, the length along the extending direction perpendicular to the cooling flow channel and the reaction flow channel is 2-3 cm, and the thickness is 0.07-0.13 mm.

9. A fuel cell plate according to any one of claims 1 to 7, characterized in that: The material of the electrode plate body is titanium alloy or stainless steel.

10. The fuel cell plate according to any one of claims 1 to 7, characterized in that: The surface of the electrode body is provided with a gold-plated layer.

11. A fuel cell, characterized in that: The fuel cell plate comprises the fuel cell plate as claimed in any one of claims 1 to 10.

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