Partition plate, fuel cell stack and vehicle

Abstract

The partition plate comprises a middle metal plate, cathode flexible graphite paper and anode flexible graphite paper, the middle metal plate is located between the cathode flexible graphite paper and the anode flexible graphite paper, and the overall size of the middle metal plate is the same as that of a bipolar plate of a fuel cell stack. The middle metal plate is provided with a hydrogen inlet, a hydrogen outlet, an air inlet, an air outlet, a coolant inlet and a coolant outlet. The partition plate disclosed by the invention has the advantages of simple structure, high reliability and convenience in installation, fluid distribution in the stack can be improved, and the occurrence of an end effect can be reduced or even prevented, so that the performance of the fuel cell stack is improved. The invention also discloses a fuel cell stack and a vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular, relates to a separator, a fuel cell stack and a vehicle. Background Art

[0002] Energy is a vital foundation for the survival and development of human society. With the depletion of traditional energy resources, environmental pollution, and growing awareness of limited energy resources, the demand for energy is gradually shifting from fossil fuels to clean energy. Proton exchange membrane fuel cells, as a clean and efficient energy device, can directly convert hydrogen into electricity. They offer advantages such as fast startup, high conversion efficiency, high power density, and low-temperature operation.

[0003] Proton exchange membrane fuel cells use an ion-conducting polymer membrane as an electrolyte, hydrogen as a fuel gas, and oxygen as an oxidant. A reaction occurs under the action of a catalyst, generating water while generating electricity, accompanied by the generation of waste heat. The fuel cell stack has the above-mentioned functions of providing the flow of reaction gases, discharging generated gases, and providing a place for the reaction to occur through heat and electrical conduction.

[0004] Bipolar plates are the core components of proton exchange membrane fuel cells (PEMFCs). They support the membrane electrodes, distribute reactant gases, collect current, and remove generated water within the stack. To meet the rated operating voltage of the load, individual cells must be stacked in series to form a higher-voltage stack. When the number of bipolar plates in a stack reaches a certain level, the performance of the cells at the ends of the stack is poor. This is related to poor cell temperature and poor flow uniformity of the reactant gases at these ends.

[0005] Existing technologies suffer from poor performance at the ends of fuel cell stacks due to the end plate effect. This can lead to operational anomalies in fuel cell stacks, such as uneven chemical reactions caused by inconsistent mass transfer and heat accumulation in the center of the stack due to heat dissipation. The end effect involves factors such as gas distribution and temperature diffusion throughout the stack. Adding certain structures to the stack can help reduce or even avoid this end effect, improving stack performance.

[0006] The Chinese patent application number 202021064298.X discloses a pseudo membrane electrode, a fuel cell stack and a vehicle. The pseudo membrane electrode includes a support frame, an anode diffusion layer and a cathode diffusion layer. The support frame includes a frame portion located in the transition zone and a support portion located in the activation zone. The anode diffusion layer and the cathode diffusion layer are arranged on both sides of the support portion. This patent supports the gas diffusion layer by the support portion of the support frame, which can improve the strength of the gas diffusion layer in the activation zone, avoid its accidental rupture, and ensure its thermal insulation and heat preservation effects. However, it mainly considers the functions of support, heat insulation and heat preservation, and does not explain the improvement of the end fluid flow.

[0007] Chinese patent application number 202320581609.7 discloses a fake membrane electrode, fake single cell, and battery stack. The fake membrane electrode includes an anode sealing frame and a cathode sealing frame; the anode sealing frame and the cathode sealing frame are arranged opposite each other and are both configured as a rectangular parallelepiped; the side walls of the anode sealing frame and / or the side walls of the cathode sealing frame are provided with an identification structure. The fake membrane electrode provided by this patent alleviates the technical problem in the prior art of being unable to distinguish between real and fake membrane electrodes with the naked eye. However, it is an assembly process optimization and no conclusion is drawn on the performance improvement of the battery stack.

[0008] It is desirable to provide an improved separator, particularly with respect to improving fluid distribution within a fuel cell stack. Summary of the Invention

[0009] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a separator for improving the distribution of fluid inside a fuel cell stack.

[0010] In order to solve the above technical problems, the technical solution adopted in the present invention is: a separator, including an intermediate metal plate, a cathode flexible graphite paper and an anode flexible graphite paper, the intermediate metal plate is located between the cathode flexible graphite paper and the anode flexible graphite paper, the outline size of the intermediate metal plate is the same as the outline size of the bipolar plate of the fuel cell stack, and a hydrogen inlet, a hydrogen outlet, an air inlet, an air outlet, a coolant inlet and a coolant outlet are provided on the intermediate metal plate.

[0011] The hydrogen inlet, the coolant outlet, and the air outlet are located at one end of the middle metal plate, and the hydrogen outlet, the coolant inlet, and the air inlet are located at the other end of the middle metal plate.

[0012] The coolant outlet is located between the hydrogen inlet and the air outlet, and the coolant inlet is located between the hydrogen outlet and the air inlet.

[0013] The cathode flexible graphite paper has the same size as the cathode side active area and reaction area of ​​the bipolar plate, and is configured to contact the cathode side active area and reaction area of ​​the bipolar plate.

[0014] The anode flexible graphite paper has the same structure and size as the anode side active area and reaction area of ​​the bipolar plate, and is configured to contact the anode side active area and reaction area of ​​the bipolar plate.

[0015] The material of the intermediate metal plate is metal.

[0016] The length of the intermediate metal plate is greater than the lengths of the cathode flexible graphite paper and the anode flexible graphite paper.

[0017] The present invention also provides a fuel cell stack, comprising a bipolar plate and the separator, wherein the separator is located between two bipolar plates and contacts the two bipolar plates.

[0018] The present invention also provides a vehicle comprising the fuel cell stack.

[0019] The separator of the present invention has the advantages of simple structure, high reliability and easy installation. It can improve the fluid distribution inside the fuel cell stack, which is beneficial to reduce or even prevent the occurrence of end effects, thereby improving the performance of the fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram of the bulkhead assembly;

[0021] Figure 2 It is a structural diagram of the middle metal plate;

[0022] Figure 3 It is a schematic diagram of the structure of cathode flexible graphite paper;

[0023] Figure 4 It is a schematic diagram of the structure of anode flexible graphite paper;

[0024] Figure 5 This is a schematic diagram of the partition assembly installation;

[0025] Figure 6 Schematic diagram of the active area and reaction area on the cathode side;

[0026] Figure 7 It is a schematic diagram of the active area and reaction area on the anode side;

[0027] The markings in the above figures are: 1. Intermediate metal plate; 11. Hydrogen inlet; 12. Hydrogen outlet; 13. Air inlet; 14. Air outlet; 15. Coolant inlet; 16. Coolant outlet; 2. Cathode flexible graphite paper; 3. Anode flexible graphite paper; 4. Stack core; 41. Hydrogen inlet manifold; 42. Hydrogen outlet manifold; 43. Air inlet manifold; 44. Air outlet manifold; 45. Coolant inlet manifold; 46. Coolant outlet manifold; 5. Bipolar plate; 51. Cathode side active area and reaction area; 52. Anode side active area and reaction area; 6. Partition assembly. DETAILED DESCRIPTION

[0028] The following is a further detailed description of the specific implementation methods of the present invention through the description of embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and to facilitate its implementation.

[0029] It should be noted that when an element is referred to as being "fixed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower" and similar expressions used in this article are for illustrative purposes only.

[0030] It should be noted that in the following embodiments, the "first", "second" and "third" do not represent an absolute distinction in structure and / or function, nor do they represent a sequence of execution, but are merely for the convenience of description.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which the present invention pertains. The terminology used herein in the specification of the present invention is for the purpose of describing specific embodiments and is not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0032] like Figures 1 to 7 As shown, the present invention provides a separator, including an intermediate metal plate 1, a cathode flexible graphite paper 2 and an anode flexible graphite paper 3, the intermediate metal plate 1 is located between the cathode flexible graphite paper 2 and the anode flexible graphite paper 3, the outline size of the intermediate metal plate 1 is the same as the outline size of the bipolar plate 5 of the fuel cell stack, and the intermediate metal plate 1 is provided with a hydrogen inlet 11, a hydrogen outlet 12, an air inlet 13, an air outlet 14, a coolant inlet 15 and a coolant outlet 16.

[0033] The hydrogen inlet 11 , the coolant outlet 16 and the air outlet 14 are located at one end of the intermediate metal plate 1 , and the hydrogen outlet 12 , the coolant inlet 15 and the air inlet 13 are located at the other end of the intermediate metal plate 1 .

[0034] The coolant outlet 16 is located between the hydrogen inlet 11 and the air outlet 14 , and the coolant inlet 15 is located between the hydrogen outlet 12 and the air inlet 13 .

[0035] The cathode flexible graphite paper 2 has the same structure and size as the cathode side active area and reaction area 51 of the bipolar plate 5 , and is configured to contact the cathode side active area and reaction area 51 of the bipolar plate 5 .

[0036] The anode flexible graphite paper 3 has the same structure and size as the anode side active area and reaction area 52 of the bipolar plate 5 , and is configured to contact the anode side active area and reaction area 52 of the bipolar plate 5 .

[0037] The material of the intermediate metal plate 1 is metal.

[0038] The length of the intermediate metal plate 1 is greater than the lengths of the cathode flexible graphite paper 2 and the anode flexible graphite paper 3 .

[0039] The present invention further provides a fuel cell stack, comprising a bipolar plate 5 and the separator, wherein the separator is located between two bipolar plates 5 and is in contact with the two bipolar plates 5 .

[0040] The present invention also provides a vehicle comprising the fuel cell stack.

[0041] Example

[0042] First, as Figures 1 to 7 As shown, an embodiment of the present invention provides a separator, including an intermediate metal plate 1, a cathode flexible graphite paper 2 and an anode flexible graphite paper 3. The intermediate metal plate 1 is located between the cathode flexible graphite paper 2 and the anode flexible graphite paper 3. The outline size of the intermediate metal plate 1 is the same as the outline size of the bipolar plate 5 of the fuel cell stack. The intermediate metal plate 1 is provided with a hydrogen inlet 11, a hydrogen outlet 12, an air inlet 13, an air outlet 14, a coolant inlet 15 and a coolant outlet 16.

[0043] Specifically, an embodiment of the present invention uses a partition that improves the fluid distribution inside the fuel cell stack, and uses it to replace the membrane electrode at the position where the end effect is prone to occur in the fuel cell stack, thereby shielding the power generation function of the end battery and avoiding the impact of long-term unstable flow of reaction gas and uneven heat on the end battery.

[0044] To prevent the emergence of new end effects, the separators, in conjunction with the bipolar plates 5, maintain gas channels, directing unstable fluid flow at the ends of the stack and ensuring stable gas flow within the stack. Furthermore, the separators are made of a highly thermally conductive material, facilitating the rapid conduction of heat generated by the stack reactions and ensuring temperature uniformity across the stack's cells.

[0045] The separator of the embodiment of the present invention has the advantages of simple structure, high reliability, and easy installation, which is conducive to reducing or even preventing the occurrence of end effects, thereby improving the performance of the fuel cell stack.

[0046] In the embodiment of the present invention, Figure 1 and Figure 2As shown, the hydrogen inlet 11, coolant outlet 16 and air outlet 14 are located at one end of the intermediate metal plate 1, and the hydrogen outlet 12, coolant inlet 15 and air inlet 13 are located at the other end of the intermediate metal plate 1. The coolant outlet 16 is located between the hydrogen inlet 11 and the air outlet 14, and the coolant inlet 15 is located between the hydrogen outlet 12 and the air inlet 13. Figure 5 As shown, the hydrogen inlet 11 is used to communicate with the hydrogen inlet manifold 41 of the fuel cell stack, the hydrogen outlet 12 is used to communicate with the hydrogen outlet manifold 42 of the fuel cell stack, the air inlet 13 is used to communicate with the air inlet manifold 43 of the fuel cell stack, the air outlet 14 is used to communicate with the air outlet manifold 44 of the fuel cell stack, the coolant inlet 15 is used to communicate with the coolant inlet manifold 45 of the fuel cell stack, and the coolant outlet 16 is used to communicate with the coolant outlet manifold 46 of the fuel cell stack, so as to ensure the circulation of fuel gas, oxidant and coolant.

[0047] In the embodiment of the present invention, Figure 3 and Figure 6 As shown, the cathode flexible graphite paper 2 is identical in structure and size to the cathode active area and reaction zone 51 of the bipolar plate 5. One side of the cathode flexible graphite paper 2 is fixedly connected to the intermediate metal plate 1. In a fuel cell stack, the cathode flexible graphite paper 2 is configured to contact the cathode active area and reaction zone 51 of the bipolar plate 5. Using flexible graphite paper can increase the contact area with the cathode active area and reaction zone 51 of the bipolar plate 5, thereby reducing contact resistance. Due to its flexibility and good conformability, graphite paper can better adapt to minor surface irregularities of the bipolar plate 5, thereby ensuring a larger contact area. Contact resistance is one of the key factors affecting fuel cell performance. High contact resistance leads to energy loss and increased temperature, thereby reducing fuel cell efficiency. Flexible graphite paper, due to its excellent conductivity and close contact with the surface of the bipolar plate 5, can significantly reduce contact resistance. This helps reduce energy loss and improve the output power and stability of the fuel cell.

[0048] In the embodiment of the present invention, Figure 4 and Figure 7As shown, the anode flexible graphite paper 3 is identical in structure and size to the anode active area and reaction zone 52 of the bipolar plate 5. One side of the anode flexible graphite paper 3 is fixedly connected to the intermediate metal plate 1. In a fuel cell stack, the anode flexible graphite paper 3 is configured to contact the anode active area and reaction zone 52 of the bipolar plate 5. Using flexible graphite paper can increase the contact area with the anode active area and reaction zone 52 of the bipolar plate 5, thereby reducing contact resistance. Due to its flexibility and good conformability, graphite paper can better adapt to minor surface irregularities of the bipolar plate 5, thereby ensuring a larger contact area. Contact resistance is one of the key factors affecting fuel cell performance. High contact resistance leads to energy loss and increased temperature, thereby reducing fuel cell efficiency. Flexible graphite paper, due to its excellent conductivity and close contact with the surface of the bipolar plate 5, can significantly reduce contact resistance. This helps reduce energy loss and improve the output power and stability of the fuel cell.

[0049] In the embodiment of the present invention, the intermediate metal plate 1 is made of metal and has a length greater than that of the cathode flexible graphite paper 2 and the anode flexible graphite paper 3 .

[0050] In the second aspect, the present invention also provides a fuel cell stack, comprising a bipolar plate 5 and a separator of the above structure, wherein the separator is located between two bipolar plates 5 and in contact with the two bipolar plates 5, and the separator and the two bipolar plates 5 in contact are located at the ends of the fuel cell stack. The specific structure of the separator can be referred to Figures 1 to 7 Since the fuel cell stack of the present invention includes the separator in the above embodiment, it has all the advantages of the above separator.

[0051] like Figure 5 As shown, in the fuel cell stack, the middle plate is aligned with the bipolar plate 5, the width direction of the middle plate is parallel to the width direction of the bipolar plate 5 and the two have the same width, the length direction of the middle plate is parallel to the length direction of the bipolar plate 5 and the two have the same width, the cathode flexible graphite paper 2 on the middle plate is in contact with the cathode side active area and reaction area 51 of the bipolar plate 5 on one side, and the anode flexible graphite paper 3 on the middle plate is in contact with the anode side active area and reaction area 52 of the bipolar plate 5 on the other side.

[0052] At locations where end effects are likely to occur in the stack, separators are used instead of membrane electrodes, thereby shielding the power generation function of the end cells and preventing the effects of long-term unstable flow of reaction gases and uneven heat on the end cells. At the same time, after adding the separator, to prevent the emergence of new end effects, it cooperates with the bipolar plate 5 to complete the retention of gas channels, diverting the unstable fluid flow at the end of the stack and ensuring the stability of gas flow within the stack. At the same time, the separator is made of a highly thermally conductive material, which is conducive to the rapid conduction of heat generated by the stack reaction and ensures the temperature uniformity of each cell in the stack.

[0053] In a third aspect, the present invention further provides a vehicle comprising a fuel cell stack having the above structure. The fuel cell stack comprises a separator having the above structure. The specific structure of the separator can be referred to Figures 1 to 7 Since the vehicle of the present invention includes the partition in the above embodiment, it has all the advantages of the above partition.

[0054] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A partition, characterized in that: It includes an intermediate metal plate, a cathode flexible graphite paper and an anode flexible graphite paper. The intermediate metal plate is located between the cathode flexible graphite paper and the anode flexible graphite paper. The outline size of the intermediate metal plate is the same as the outline size of the bipolar plate of the fuel cell stack. The intermediate metal plate is provided with a hydrogen inlet, a hydrogen outlet, an air inlet, an air outlet, a coolant inlet and a coolant outlet.

2. The separator according to claim 1, characterized in that: The hydrogen inlet, the coolant outlet and the air outlet are located at one end of the middle metal plate, and the hydrogen outlet, the coolant inlet and the air inlet are located at the other end of the middle metal plate.

3. The separator according to claim 1, characterized in that: The coolant outlet is located between the hydrogen inlet and the air outlet, and the coolant inlet is located between the hydrogen outlet and the air inlet.

4. The separator according to any one of claims 1 to 3, characterized in that: The cathode flexible graphite paper has the same structural size as the cathode side active area and reaction area of ​​the bipolar plate, and the cathode flexible graphite paper is configured to contact the cathode side active area and reaction area of ​​the bipolar plate.

5. The separator according to any one of claims 1 to 3, characterized in that: The anode flexible graphite paper has the same structural size as the anode side active area and reaction area of ​​the bipolar plate, and is configured to contact the anode side active area and reaction area of ​​the bipolar plate.

6. The separator according to any one of claims 1 to 5, characterized in that: The material of the middle metal plate is metal.

7. The separator according to any one of claims 1 to 5, characterized in that: The length of the intermediate metal plate is greater than the lengths of the cathode flexible graphite paper and the anode flexible graphite paper.

8. A fuel cell stack, comprising a bipolar plate, characterized in that: It also includes the separator according to any one of claims 1 to 7, wherein the separator is located between the two bipolar plates and the separator is in contact with the two bipolar plates.

9. A vehicle, characterized in that: Comprising the fuel cell stack as described in claim 8.

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