Fuel cell plate structure and fuel cell cell

Abstract

The application discloses a fuel cell pole plate structure and a fuel cell single cell, and the fuel cell pole plate structure comprises a pole plate body and a flow field, the flow field is arranged on the pole plate body, and the flow field comprises a first gas inlet distribution area and a first reaction flow field area; the first gas inlet distribution area comprises a plurality of first distribution flow channels arranged side by side; the first reaction flow field area comprises a plurality of first basic flow channels; two of the plurality of first distribution flow channels are a first flow channel and a second flow channel respectively; the length of the first flow channel is smaller than the length of the second flow channel; the first flow channel is communicated with N first basic flow channels; the second flow channel is communicated with M first basic flow channels; and N is greater than or equal to M. According to the fuel cell pole plate structure, the pressure and supply amount of the gas entering the first reaction flow field area from the first gas inlet distribution area are consistent, the reaction rate of the first reaction flow field area is balanced, and the energy conversion efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell electrode structure and a fuel cell single cell. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) offer advantages such as high power generation efficiency and environmental friendliness, and have broad application prospects. An efficient hydrothermal management system is crucial for improving fuel cell performance and extending its lifespan. The bipolar plate is a key component of a PEMFC. The flow field on the bipolar plate can, on the one hand, uniformly distribute gas into the gas diffusion layer, thereby ensuring a uniform distribution of current density and temperature generated by the electrochemical reaction; on the other hand, it can promptly discharge the generated water from the stack. Therefore, a rational design of the flow field is essential for improving the performance of fuel cell hydrothermal management.

[0003] Currently, common flow fields in proton exchange membrane fuel cells include parallel flow fields, serpentine flow fields, and interdigitated flow fields. Interdigitated flow fields are characterized by discontinuous channels. During flow, gas is forced to diffuse into surrounding channels due to channel blockage. This process allows more gas to enter the catalyst layer for reaction, improving gas utilization and power density. However, forced diffusion through the diffusion layer generates a significant pressure drop. If the airflow is too large, forced convection may damage the diffusion layer, thus reducing battery performance. Parallel flow fields are widely used in fuel cells, but their smaller pressure drop and numerous branch channels result in uneven gas flow throughout the field, leading to poor mass transfer and severely impacting the battery's output power. Furthermore, excessively wide parallel flow channels can cause uneven gas distribution and drainage difficulties. Serpentine flow fields offer better drainage, but their long channels and large pressure drop mean that electrochemical reactions mainly occur in the front section of the serpentine channel, while the rear section has insufficient reactant gas, affecting fuel cell performance.

[0004] Therefore, it is urgent to propose a flow field structure for fuel cells to overcome the problem of uneven gas distribution after gas enters the flow field of the fuel cell reaction zone, thereby improving the performance of fuel cells. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a fuel cell electrode structure in which the pressure and supply of gas entering the first reaction flow field region from the first gas inlet distribution region are relatively consistent, resulting in a more balanced reaction rate in the first reaction flow field region, which is beneficial to improving energy conversion efficiency.

[0006] According to an embodiment of the present invention, a fuel cell electrode structure includes: an electrode body, wherein an air inlet and an air outlet are respectively provided at both ends along a first direction; a flow field, wherein the flow field is disposed on the electrode body and located between the air inlet and the air outlet, and the flow field is connected to the air inlet and the air outlet respectively; the flow field includes a first air inlet distribution area and a first reaction flow field area arranged sequentially along the first direction, wherein the first air inlet distribution area is used to uniformly distribute gas from the air inlet into the first reaction flow field area; the first air inlet distribution area includes a plurality of first distribution channels arranged side by side along a second direction, and the first reaction flow field area includes a plurality of first basic channels arranged side by side along the second direction, wherein the first direction and the second direction are perpendicular to each other, wherein two of the plurality of first distribution channels are respectively a first channel and a second channel, the length of the first channel is less than the length of the second channel, the first channel is connected to N first basic channels, and the second channel is connected to M first basic channels, and satisfies: N≥M.

[0007] According to the fuel cell electrode structure of the present invention, different numbers of first basic flow channels can be matched according to the different lengths of the first flow channel and the second flow channel, so that the pressure and supply of the gas entering the first reaction flow field from the first gas inlet distribution area are more consistent, and the reaction rate of the first reaction flow field is more balanced, which is beneficial to improving energy conversion efficiency.

[0008] In addition, the fuel cell electrode structure according to the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the lengths of a plurality of first distribution channels gradually increase toward the center of the electrode body; the lengths of a plurality of first basic channels corresponding to each first distribution channel gradually decrease; wherein, two of the N first basic channels corresponding to the first channel are first side channels and second side channels, the second side channel is located on the side of the first side channel close to the second channel, and among the M first basic channels corresponding to the second channel, the first basic channel close to the second side channel is the third side channel, the first basic channel far from the second side channel is the fourth side channel, the length of the third side channel is less than the length of the second side channel, the length of the third side channel is greater than the length of the first side channel, and the length of the fourth side channel is greater than the length of the second side channel.

[0010] In some embodiments of the present invention, along the flow direction of the airflow, the first distribution channel includes a first segment and a second segment, the first segment extending along the first direction, and the second segment extending toward the center of the electrode body to communicate with the first basic channel extending along the first direction, wherein the lengths of the first segments of the plurality of first distribution channels are equal, and the lengths of the plurality of second segments gradually increase toward the center of the electrode body.

[0011] In some embodiments of the present invention, the flow field further includes a second air intake distribution area and a second reaction flow field area arranged sequentially along the first direction. The second air intake distribution area and the first air intake distribution area are arranged side by side along the second direction, and the second reaction flow field area and the first reaction flow field area are arranged side by side along the second direction. The second air intake distribution area is used to allow gas to flow uniformly into the second reaction flow field area from the air inlet. The distance between the air inlet and the first reaction flow field area is less than the distance between the air inlet and the second reaction flow field area. The second air intake distribution area includes a plurality of second distribution channels arranged side by side. The second reaction flow field area includes a plurality of second basic channels arranged side by side along the second direction. Along the gas flow direction, the second distribution channel includes a primary channel and a secondary channel. The primary channel connects the air inlet and the secondary channel. The secondary channel includes a first branch channel and a second branch channel. The outlet end of the first branch channel and the outlet end of the second branch channel are respectively connected to at least one second basic channel.

[0012] In some embodiments of the present invention, the primary flow channel includes a third segment and a fourth segment, the third segment extending along a first direction, and the fourth segment inclined toward a side away from the first intake distribution area, wherein multiple third segments are of equal length and, in the direction toward the first intake distribution area, the length of the fourth segment gradually increases; the second basic flow channel includes a fifth segment and a sixth segment, the fifth segment extending along the first direction, and the sixth segment inclined toward a side of the first intake distribution area; both the first branch flow channel and the second branch flow channel extend along the second direction, the second branch flow channel is located on the side of the first branch flow channel closer to the second reaction flow field area, and the length of the first branch flow channel is greater than the length of the second branch flow channel.

[0013] In some embodiments of the present invention, the flow field further includes a third air intake distribution area and a third reaction flow field area arranged sequentially along the first direction. Along the second direction, the third air intake distribution area is located between the first air intake distribution area and the second air intake distribution area, and is used to allow gas to flow uniformly from the air inlet into the third reaction flow field area. The third air intake distribution area includes a plurality of third distribution channels arranged side by side along the second direction. The third reaction flow field area includes a plurality of third basic channels arranged side by side along the second direction. Each of the third distribution channels is connected to P of the third basic channels, wherein each of the secondary channels is connected to Q1 of the second basic channels, and satisfies: M > P > Q1.

[0014] In some embodiments of the present invention, the cross-sectional area of ​​the first basic flow channel, the cross-sectional area of ​​the second basic flow channel, and the cross-sectional area of ​​the third basic flow channel are all equal.

[0015] In some embodiments of the present invention, the secondary flow channel further includes a single flow channel along the second direction. The single flow channel is located on the side of the second distribution flow channel away from the first distribution flow channel. The single flow channel is connected to Q2 of the second basic flow channels and satisfies: M > P > Q1 ≥ Q2.

[0016] In some embodiments of the present invention, the flow field is arranged symmetrically about the geometric center point of the electrode body.

[0017] In some embodiments of the present invention, the flow field includes an intake distribution area, a reaction flow field area, and an exhaust distribution area arranged sequentially along a first direction. The intake distribution area includes a first intake distribution area, a second intake distribution area, and a third intake distribution area arranged side-by-side along a second direction. The reaction flow field area includes a first reaction flow field area, a second reaction flow field area, and a third reaction flow field area arranged side-by-side along the second direction. The exhaust distribution area includes a first exhaust distribution area, a second exhaust distribution area, and a third exhaust distribution area arranged side-by-side along the second direction. Along the first direction, the first reaction flow field area is located at the first intake area. Between the distribution area and the first outlet distribution area, the second reaction flow field area is located between the second inlet distribution area and the second outlet distribution area, and the third reaction flow field area is located between the third inlet distribution area and the third outlet distribution area. The first inlet distribution area and the third outlet distribution area are arranged symmetrically about the geometric center point of the electrode body; the second inlet distribution area and the first outlet distribution area are arranged symmetrically about the geometric center point of the electrode body; the third inlet distribution area and the second outlet distribution area are arranged symmetrically about the geometric center point of the electrode body.

[0018] The present invention also proposes a fuel cell cell having the fuel cell electrode structure described in the above embodiments.

[0019] According to an embodiment of the present invention, a fuel cell unit includes a membrane electrode assembly, an anode plate, and a cathode plate. The cathode plate, the membrane electrode assembly, and the anode plate are stacked sequentially to form the fuel cell unit. The anode plate and / or the cathode plate are fuel cell electrode plate structures as described in the above embodiments.

[0020] According to embodiments of the present invention, by setting the fuel cell electrode structure of the above embodiments, the energy conversion efficiency of the fuel cell can be improved.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 These are schematic diagrams of the flow field structure in some embodiments of the present invention.

[0024] Figure 2 This is an exploded view of the flow field along the second direction in some embodiments of the present invention.

[0025] Figure 3 yes Figure 1 A magnified view of region A in the middle.

[0026] Figure 4 yes Figure 1 A magnified view of region B in the middle.

[0027] Figure 5 This is a schematic diagram of the structure of the second air intake distribution area according to some embodiments of the present invention.

[0028] Figure 6 yes Figure 2 A magnified view of region C in the middle.

[0029] Figure label:

[0030] 10. Flow field;

[0031] 1. Air intake distribution area;

[0032] 11. First intake distribution area; 111. First distribution channel; 1111. First channel; 1112. Second channel; 101. First section; 102. Second section;

[0033] 12. Second intake distribution area; 121. Second distribution channel; 122. Single channel;

[0034] 1211, Primary flow channel; 103, Third section; 104, Fourth section;

[0035] 1212, Secondary flow channel; 1201, First branch flow channel; 1202, Second branch flow channel;

[0036] 13. Third intake distribution area; 131. Third distribution channel;

[0037] 2. Reaction flow field region;

[0038] 21. First reaction flow field region; 211. First basic flow channel;

[0039] 22. Second reaction flow field region; 221. Second basic flow channel; 105. Fifth section; 106. Sixth section;

[0040] 23. Third reaction flow field region; 231. Third basic flow channel;

[0041] 3. Gas distribution zone; 31. First gas distribution zone; 32. Second gas distribution zone; 33. Third gas distribution zone;

[0042] X, the first direction; Y, the second direction. Detailed Implementation

[0043] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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 according to the specific circumstances.

[0046] The following is for reference. Figures 1-6 A fuel cell electrode structure according to an embodiment of the present invention is described.

[0047] like Figures 1-3 As shown, the fuel cell electrode structure includes an electrode body and a flow field 10. The electrode body has an inlet and an outlet at both ends along the first direction X. The flow field 10 is disposed on the electrode body and located between the inlet and outlet, communicating with both the inlet and outlet. The flow field 10 includes a first inlet distribution region 11 and a first reaction flow field region 21 arranged sequentially along the first direction X. The first inlet distribution region 11 is used to uniformly distribute gas from the inlet into the first reaction flow field region 21. The first inlet distribution region 11 includes parallel arrangement along the second direction Y. The first reaction flow field region 21 includes multiple first distribution channels 111 arranged side by side along the second direction Y. The first direction X and the second direction Y are perpendicular to each other. Among the multiple first distribution channels 111, two are first channel 1111 and second channel 1112, respectively. The length of the first channel 1111 is less than the length of the second channel 1112. The first channel 1111 is connected to N first basic channels 211, and the second channel 1112 is connected to M first basic channels 211, and satisfies: N≥M.

[0048] In other words, the fuel cell electrode structure divides the flow field 10 into a first intake distribution area 11 and a first reaction flow field area 21. The intake air can be pre-distributed in the first intake distribution area 11 before being introduced into the first reaction flow field area 21. Specifically, the first flow channel 1111 and the second flow channel 1112 of different lengths in the first intake distribution area 11 can generate different pressure drops. Specifically, the shorter first flow channel 1111 has a smaller pressure drop, which allows the first flow channel 1111 to connect more of the first basic flow channels 211, while the longer second flow channel 1112 has a larger pressure drop, which allows the second flow channel 1112 to connect fewer of the first basic flow channels 211. As a result, the pressure of the gas entering the first basic flow channel 211 from the first flow channel 1111 is more consistent with the pressure of the gas entering the second basic flow channel 221 from the second flow channel 1112, so that the gas can enter the first reaction flow field area 21 more evenly from the first intake distribution area 11.

[0049] Furthermore, the gas in the first reaction flow field region 21 can come into better contact with the electrode catalyst attached to the electrode plate, and undergo an oxidation-reduction reaction to convert chemical energy into electrical energy. Since the gas pressure and supply in each first basic flow channel 211 are relatively consistent, the reaction rate in the first reaction flow field region 21 can be relatively balanced, which can better reduce the fluctuation of reaction efficiency caused by excessive or insufficient gas in local areas, and is conducive to improving energy conversion efficiency.

[0050] Furthermore, the remaining gas after the reaction and the byproducts generated by the reaction can flow along the first basic flow channel 211 towards the gas outlet of the electrode plate, and then be discharged from the gas outlet, forming a complete gas flow and reaction cycle. Here, M and N are both positive integers greater than 1, and P, Q1, and Q2 are also positive integers greater than 1, which will not be elaborated further below.

[0051] For example, the first direction X can be the length direction of the electrode body, and the second direction Y can be the direction of the cross-sectional area of ​​the electrode body.

[0052] According to the fuel cell electrode structure of the present invention, different numbers of first basic flow channels 211 can be matched according to the different lengths of the first flow channel 1111 and the second flow channel 1112, so that the pressure and supply of the gas entering the first reaction flow field region 21 from the first gas inlet distribution region 11 are more consistent, and the reaction rate of the first reaction flow field region 21 is more balanced, which is beneficial to improving the energy conversion efficiency.

[0053] In some embodiments of the present invention, the first distribution channel 111 within a first length range is always the first channel 1111, and the first distribution channel 111 within a second length range is always the second channel 1112.

[0054] In other words, multiple first distribution channels 111 can be arranged side by side along the second direction Y. The length of the multiple first distribution channels 111 can be gradually increased. As the length of the first distribution channels 111 increases, the pressure drop effect of the gas gradually increases. However, if each first distribution channel 111 is matched with a different number of first basic channels 211, it will easily increase the processing difficulty. Therefore, the first distribution channels 111 within the first length range can all be first channels 1111, so that the first distribution channels 111 within this first length range are connected with the same number of first basic channels 211. Similarly, the first distribution channels 111 within the second length range are connected with the same number of first basic channels 211.

[0055] Specifically, the first distribution channel 111 within the first length range can be connected to six first basic channels 211, and the first distribution channel 111 within the second length range can be connected to four first basic channels 211. Similarly, the first intake distribution area 11 can also have a first distribution channel 111 within the third length range, etc. This application does not limit this.

[0056] In some embodiments of the present invention, such as Figures 1-3 As shown, the lengths of multiple first distribution channels 111 gradually increase in the direction towards the center of the electrode body; the lengths of multiple first basic channels 211 corresponding to each first distribution channel 111 gradually decrease; among the N first basic channels 211 corresponding to the first channel 1111, two are first side channels and second side channels, the second side channel is located on the side of the first side channel close to the second channel 1112, among the M first basic channels 211 corresponding to the second channel 1112, the first basic channel 211 close to the second side channel is the third side channel, the first basic channel 211 far from the second side channel is the fourth side channel, the length of the third side channel is less than the length of the second side channel, the length of the third side channel is greater than the length of the first side channel, and the length of the fourth side channel is greater than the length of the second side channel.

[0057] Regarding the "direction toward the center of the electrode body", it should be noted that the first air intake distribution area 11 is located on one side of the second direction Y of the electrode body. The "direction toward the center of the electrode body" can be understood as the direction from the edge of the electrode body toward the center along the second direction Y. That is, the closer to the center, the longer the corresponding first distribution channel 111 is.

[0058] In other words, the longer the first distribution channel 111, the greater the pressure drop. Similarly, the longer the first basic channel 211, the greater the pressure drop. Therefore, by designing the length of the multiple first basic channels 211 corresponding to each first distribution channel 111, this invention can better balance the pressure difference of the gas in different flow channels, thereby making the gas velocity in the first reaction flow field region 21 more uniform, and thus making the reaction rate in the first reaction flow field region 21 more balanced, which is beneficial to improving energy conversion efficiency.

[0059] In some embodiments of the present invention, such as Figures 1-3 As shown, along the flow direction of the airflow, the first distribution channel 111 includes a first segment 101 and a second segment 102. The first segment 101 extends along the first direction X, and the second segment 102 extends toward the center of the electrode body to communicate with the first basic channel 211 extending along the first direction X. The first segments 101 of the plurality of first distribution channels 111 have equal lengths and the lengths of the plurality of second segments 102 gradually increase toward the center of the electrode body.

[0060] refer to Figure 1 and Figure 2 As shown, the first segment 101 and the first basic flow channel 211 connected to the first segment 101 are arranged at intervals along the second direction Y. The second segment 102 connects the first segment 101 and the first basic flow channel 211. Multiple first segments 101 are arranged side by side along the second direction Y, and are at the same position at both ends of the first direction X. The second segments 102 are arranged at an angle, and multiple second segments 102 are parallel to each other. This arrangement can better connect the first basic flow channels 211 at different positions. Furthermore, the above arrangement is relatively neat and compact, which can make better use of the space of the electrode body, thereby helping to improve the gas delivery rate.

[0061] In some embodiments of the present invention, such as Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the flow field 10 also includes a second air intake distribution zone 12 and a second reaction flow field zone 22 arranged sequentially along the first direction X. The second air intake distribution zone 12 and the first air intake distribution zone 11 are arranged side by side along the second direction Y. The second reaction flow field zone 22 and the first reaction flow field zone 21 are arranged side by side along the second direction Y. The second air intake distribution zone 12 is used to make gas flow evenly from the air inlet into the second reaction flow field zone 22. The distance between the air inlet and the first reaction flow field zone 21 is smaller than the distance between the air inlet and the second reaction flow field zone 22. The second air intake distribution zone 12 includes a plurality of second air intake distribution zones arranged side by side. The second distribution channel 121; the second reaction flow field region 22 includes a plurality of second basic channels 221 arranged side by side along the second direction Y, wherein, along the gas flow direction, the second distribution channel 121 includes: a primary channel 1211 and a secondary channel 1212, the primary channel 1211 is connected between the air inlet and the secondary channel 1212, the secondary channel 1212 includes a first branch channel 1201 and a second branch channel 1202, the outlet end of the first branch channel 1201 and the outlet end of the second branch channel 1202 are respectively connected to at least one second basic channel 221.

[0062] In other words, since the distance from the air inlet to the first reaction flow field region 21 is shorter than the distance to the second reaction flow field region 22, the traditional single distribution structure is prone to insufficient gas supply or excessive pressure drop in the second reaction flow field region 22. In this structure, the second air inlet distribution region 12 and the first air inlet distribution region 11 are parallel to each other along the second direction Y. A separate distribution path is designed for the long-distance characteristics of the second reaction flow field region 22, which can alleviate the gas supply difference between near and far regions under a single path and is conducive to uniform gas distribution.

[0063] Furthermore, the primary flow channel 1211 first receives the inlet gas to achieve initial pressure stabilization, and then the gas is diverted through the first branch flow channel 1201 and the second branch flow channel 1202, allowing the gas to undergo secondary distribution before entering the second basic flow channel 221. The parallel structure of the dual-branch flow channels formed by the first branch flow channel 1201 and the second branch flow channel 1202 can better disperse the gas velocity and avoid uneven pressure attenuation caused by the long path of a single flow channel. Then, each second branch flow channel 1202 can be connected to at least one second basic flow channel 221, which allows the gas to enter the second basic flow channel 221 more evenly and helps to make the inlet gas parameters of each second basic flow channel 221 more consistent. For example, each second branch flow channel 1202 can be connected to two second basic flow channels 221, or it can be one or three, which is not limited in this application.

[0064] Furthermore, the parallel design of the first reaction flow field region 21 and the second reaction flow field region 22 can effectively improve the plate reaction efficiency and adaptability. The gas distribution in the first reaction flow field region 21 and the second reaction flow field region 22 can be independently adjusted according to requirements to adapt to different power output scenarios. At the same time, the branch design of the second distribution channel 121 makes the gas flow path more flexible. By adjusting the parameters of the branch channel, it can adapt to the different positional requirements of the second reaction flow field region 22, further optimizing the overall reaction balance.

[0065] In some embodiments of the present invention, the cross-sectional area of ​​the first branch channel 1201 and the cross-sectional area of ​​the second branch channel 1202 are both smaller than the cross-sectional area of ​​the primary channel 1211.

[0066] In other words, the wider cross-section of the primary flow channel 1211 can effectively reduce the gas velocity at the inlet, buffer the airflow impact, and achieve initial pressure stabilization, avoiding the impact of initial gas fluctuations on the uniformity of distribution. When the gas enters the relatively narrow first branch flow channel 1201 and second branch flow channel 1202, the gas velocity is moderately increased, which can effectively enhance the propulsion force of the gas in the second reaction flow field region 22, effectively offset the pressure attenuation during long-distance transmission, and solve the problem of insufficient gas supply in the far-end basic flow channel.

[0067] Furthermore, the first branch channel 1201 and the second branch channel 1202 with narrow cross-sectional area have higher sensitivity to gas flow rate adjustment and can better match the air intake requirements of each second basic channel 221.

[0068] In some embodiments of the present invention, the cross-sectional area of ​​the primary flow channel 1211 is equal to the cross-sectional area of ​​the first distribution flow channel 111.

[0069] In other words, when the inlet gas is diverted to the first distribution channel 111 (adapted to the near-distance first reaction flow field region 21) and the first-stage channel 1211 (adapted to the far-distance second reaction flow field region 22), the channel cross-sections with the same flow cross-sectional area make the initial pressure loss of the two airflows consistent, avoiding the problem of one gas path being preferentially guided and the other gas supply being delayed due to the difference in the flow cross-sectional area of ​​the channels.

[0070] In some embodiments of the present invention, such as Figure 1 , Figure 2 , Figure 4 and Figure 5 and Figure 6 As shown, the primary flow channel 1211 includes a third segment 103 and a fourth segment 104. The third segment 103 extends along the first direction X, and the fourth segment 104 is inclined toward the side away from the first intake distribution area 11. The multiple third segments 103 are of equal length and face the first intake distribution area 11. The length of the fourth segment 104 gradually increases. The second basic flow channel 221 includes a fifth segment 105 and a sixth segment 106. The fifth segment 105 extends along the first direction X, and the sixth segment 106 is inclined toward the side of the first intake distribution area 11. The first branch flow channel 1201 and the second branch flow channel 1202 both extend along the second direction Y. The second branch flow channel 1202 is located on the side of the first branch flow channel 1201 close to the second reaction flow field area 22. The length of the first branch flow channel 1201 is greater than the length of the second branch flow channel 1202.

[0071] In other words, the equal-length design of the third segment 103 helps to achieve a more balanced pressure in the initial intake section, allowing the gas to flow smoothly along the first direction X and avoiding pressure fluctuations during initial flow splitting. The fourth segment 104 is gradually lengthened along the second direction Y, which can better match the second basic flow channel 221 at different locations, offsetting the pressure attenuation of the far-end flow channel and helping to make the gas supply parameters of each branch flow channel more consistent. Secondly, the secondary flow channel 1212 (i.e., the first branch flow channel 1201 and the second branch flow channel 1202) extends along the second direction Y, connecting the inclined fourth segment 104 and the sixth segment 106 at both ends, forming a smoother gas flow path, reducing eddies and stagnation at the flow channel corners, reducing pressure loss while improving gas transmission efficiency. In addition, the segmented inclined design of the fifth segment 105 and the sixth segment 106 of the second basic flow channel 221, together with the inclined segment of the first-stage flow channel 1211, makes the gas distribution more uniform when flowing into the reaction zone, which helps to expand the catalyst contact area and improve reaction efficiency.

[0072] In some embodiments of the present invention, such as Figures 1-5As shown, the flow field 10 also includes a third intake distribution zone 13 and a third reaction flow field zone 23 arranged sequentially along the first direction X. Along the second direction Y, the third intake distribution zone 13 is located between the first intake distribution zone 11 and the second intake distribution zone 12, and is used to ensure that gas flows uniformly from the intake port into the third reaction flow field zone 23. The third intake distribution zone 13 includes a plurality of third distribution channels 131 arranged side-by-side along the second direction Y. The third reaction flow field zone 23 includes a plurality of third basic channels 231 arranged side-by-side along the second direction Y. Each third distribution channel 131 is connected to P third basic channels 231, wherein each secondary channel 1212 is connected to Q1 second basic channels 221, and satisfies: M > P > Q1. For example, the plurality of third basic channels 231 have the same length.

[0073] In other words, the third intake distribution zone 13 is located between the first intake distribution zone 11 and the second intake distribution zone 12, forming a centrally buffered gas distribution hierarchy. Combined with the design of each third distribution channel 131 connecting to P third basic channels 231, this creates a gradient difference with the M value of the first distribution channel 111 and the Q1 value of the secondary channel 1212. This effectively matches the spatial positions and flow resistance differences of the three reaction flow field zones 2, preventing oversupply or undersupply in different areas due to varying locations. Furthermore, the gradient connectivity design, in conjunction with the three-section channel layout, makes the gas distribution in the three reaction flow field zones 2 more hierarchical. This not only ensures sufficient gas supply to the near-end first reaction flow field zone 21 but also takes into account pressure compensation in the middle third reaction flow field zone 23 and the far-end second reaction flow field zone 22, thus achieving better overall gas concentration balance.

[0074] In some embodiments of the present invention, the cross-sectional area of ​​the first basic flow channel 211, the cross-sectional area of ​​the second basic flow channel 221, and the cross-sectional area of ​​the third basic flow channel 231 are all equal.

[0075] In other words, a uniform flow channel cross-sectional area helps ensure consistent gas flow resistance across all reaction flow field zones 2. Combined with the differentiated flow channel design of the three inlet distribution zones 1, this allows for better control of inlet flow rate and pressure in each zone, avoiding the introduction of additional resistance variables due to differences in flow channel cross-sectional area, and facilitating balanced gas distribution across the entire region. Furthermore, a basic flow channel with an equal flow cross-sectional area helps maintain consistent catalyst contact area and reaction environment in each reaction zone, promoting synchronized electrochemical reaction rates in the three reaction flow field zones 2. This avoids thermal stress concentration caused by local reaction imbalances, effectively improving the stability of fuel cell output power and extending the overall lifespan of the plates and the battery.

[0076] In some embodiments of the present invention, such as Figures 1-2As shown, the secondary flow channel 1212 also includes a single flow channel 122 along the second direction Y. The single flow channel 122 is located on the side of the second distribution flow channel 121 away from the first distribution flow channel 111. The single flow channel 122 is connected to Q2 second basic flow channels 221 and satisfies: M>P>Q1≥Q2.

[0077] In other words, the single flow channel 122 is located in the outermost region farthest from the air inlet, and the number of corresponding connected second basic flow channels 221 Q2 is the smallest. By reducing the number of branch channels, the pressure attenuation of the far-end flow channel can be offset, and the insufficient air supply in the outer region due to the excessively long path can be avoided. Secondly, the design of Q1≥Q2 ensures that the air supply capacity of the second distribution flow channel 121 and the single flow channel 122 are connected in an orderly manner, preventing excessive gas accumulation in the outer region and ensuring the balanced flow rate inside the second reaction flow field region 22.

[0078] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the flow field 10 is arranged symmetrically about the geometric center point of the electrode body.

[0079] In other words, the flow field 10 is symmetrical about the geometric center of the electrode body, ensuring that any flow channel in the flow field 10 can be matched with a corresponding flow channel structure on the other side of the center point. The length, direction, and cross-sectional parameters of these two channels are completely identical. After the gas flows in from the inlet, the pressure attenuation and velocity changes within the symmetrical flow channels are centrally symmetrically distributed. Combined with the gradient design of the first inlet distribution zone 11, the second inlet distribution zone 12, and the third inlet distribution zone 13, this facilitates balanced gas distribution. Furthermore, the centrally symmetrical structure allows the electrochemical reaction to be centrally symmetrically distributed on the electrode body, preventing unilateral accumulation of heat and products. This effectively disperses the heat load, better avoids localized high-temperature hotspots, and reduces the risk of warping and deformation of the electrode due to uneven thermal stress.

[0080] In some embodiments of the present invention, such as Figures 1-5As shown, the flow field 10 includes an intake distribution zone 1, a reaction flow field zone 2, and an exhaust distribution zone 3 arranged sequentially along a first direction X. The intake distribution zone 1 includes a first intake distribution zone 11, a second intake distribution zone 12, and a third intake distribution zone 13 arranged side-by-side along a second direction Y. The reaction flow field zone 2 includes a first reaction flow field zone 21, a second reaction flow field zone 22, and a third reaction flow field zone 23 arranged side-by-side along a second direction Y. The exhaust distribution zone 3 includes a first exhaust distribution zone 31, a second exhaust distribution zone 32, and a third exhaust distribution zone 33 arranged side-by-side along a second direction Y. Along the first direction X, the first reaction flow field zone 21 is located at... Between the first intake distribution zone 11 and the first exhaust distribution zone 31, the second reaction flow field zone 22 is located between the second intake distribution zone 12 and the second exhaust distribution zone 32, and the third reaction flow field zone 23 is located between the third intake distribution zone 13 and the third exhaust distribution zone 33. The first intake distribution zone 11 and the third exhaust distribution zone 33 are arranged symmetrically about the geometric center point of the electrode body; the second intake distribution zone 12 and the first exhaust distribution zone 31 are arranged symmetrically about the geometric center point of the electrode body; and the third intake distribution zone 13 and the second exhaust distribution zone 32 are arranged symmetrically about the geometric center point of the electrode body.

[0081] In other words, the first inlet distribution zone 11 and the third outlet distribution zone 33, the second inlet distribution zone 12 and the first outlet distribution zone 31 are all arranged symmetrically about the geometric center point of the electrode body, and the third inlet distribution zone 13 and the second outlet distribution zone 32 are arranged symmetrically about the geometric center point of the electrode body. This makes the gas flow path from inlet to outlet centrally symmetrically distributed, and the pressure attenuation and flow rate change form a mirror compensation, which can better reduce the resistance deviation of the single-sided flow channel, which is conducive to the bidirectional balance of inlet and outlet, and can better improve the utilization rate of reactants.

[0082] The following is for reference. Figures 1-5 The structure of the flow field 10 according to a specific embodiment of the present invention is described.

[0083] The flow field 10 includes an intake distribution area 1, a reaction flow field area 2, and an exhaust distribution area 3 arranged sequentially along the first direction X. Along the second direction Y, the intake distribution area 1 includes a plurality of first distribution channels 111, a plurality of third distribution channels 131, a plurality of second distribution channels 121, and a single channel 122 arranged side by side. The reaction flow field area 2 includes a plurality of first basic channels 211, a plurality of third basic channels 231, and a plurality of second basic channels 221 arranged side by side. The exhaust distribution area 3 includes a plurality of first exhaust distribution channels, a plurality of third exhaust distribution channels, and a plurality of second exhaust distribution channels arranged side by side.

[0084] The specific connectivity along the second direction Y is as follows:

[0085] The outermost first distribution channel 111 is connected to six first basic channels 211, and then these six first basic channels 211 are connected to three first outlet distribution channels in pairs.

[0086] Five adjacent first distribution channels 111, each of which is connected to four first basic channels 211, and then two first basic channels 211 are grouped together and connected to a first outlet distribution channel.

[0087] There are four third distribution channels 131. Each third distribution channel 131 is connected to three third basic channels 231, and then connected to a corresponding third outlet distribution channel.

[0088] There are five second distribution channels 121. Each second distribution channel 121 includes a primary channel 1211 and a secondary channel 1212. Each secondary channel 1212 includes a first branch channel 1201 and a second branch channel 1202. The first branch channel 1201 is connected to two second basic channels 221, and the second branch channel 1202 is connected to two second basic channels 221. There are two single channels 122, and each single channel 122 is connected to two second basic channels 221. The four second basic channels 221 are connected to one second outlet distribution channel.

[0089] The present invention also proposes a fuel cell cell having the fuel cell electrode structure described in the above embodiments.

[0090] According to an embodiment of the present invention, a fuel cell unit includes a membrane electrode assembly, an anode plate, and a cathode plate. The cathode plate, the membrane electrode assembly, and the anode plate are stacked sequentially to form a fuel cell unit. The anode plate and / or the cathode plate are the fuel cell electrode plate structures described in the above embodiments.

[0091] For example, a fuel cell unit includes a membrane electrode assembly, an anode plate, and a fuel cell electrode plate structure as described in the above embodiments. The fuel cell electrode plate structure, the membrane electrode assembly, and the anode plate are stacked sequentially to form a fuel cell unit.

[0092] For example, a fuel cell unit includes a membrane electrode assembly and two fuel cell electrode structures as described in the above embodiments. The fuel cell unit is formed by stacking the fuel cell electrode structures, the membrane electrode assembly, and the fuel cell electrode structures in sequence.

[0093] According to embodiments of the present invention, by setting the fuel cell electrode structure of the above embodiments, the energy conversion efficiency of the fuel cell can be improved.

[0094] The fuel cell plate structure, other components of the fuel cell, and operation according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0095] In the description of this specification, references to terms such as "some embodiments," "optionally," "furthermore," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0096] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A fuel cell electrode structure, characterized in that, include: The electrode body has an air inlet and an air outlet at both ends along the first direction (X); Flow field (10), the flow field (10) is disposed on the electrode plate body and located between the air inlet and the air outlet, the flow field (10) is connected to the air inlet and the air outlet respectively; The flow field (10) includes a first air inlet distribution area (11) and a first reaction flow field area (21) arranged sequentially along the first direction (X). The first air inlet distribution area (11) is used to make the gas flow into the first reaction flow field area (21) evenly distributed from the air inlet. The first intake distribution area (11) includes a plurality of first distribution channels (111) arranged side by side along the second direction (Y), and the first reaction flow field area (21) includes a plurality of first basic channels (211) arranged side by side along the second direction (Y). The first direction (X) and the second direction (Y) are perpendicular to each other. Two of the plurality of first distribution channels (111) are respectively a first channel (1111) and a second channel (1112). The length of the first channel (1111) is less than the length of the second channel (1112). The first channel (1111) is connected to N first basic channels (211), and the second channel (1112) is connected to M first basic channels (211), satisfying: N≥M. The flow field (10) further includes a second air inlet distribution area (12) and a second reaction flow field area (22) arranged sequentially along the first direction (X). The second air inlet distribution area (12) and the first air inlet distribution area (11) are arranged side by side along the second direction (Y). The second reaction flow field area (22) and the first reaction flow field area (21) are arranged side by side along the second direction (Y). The second air inlet distribution area (12) is used to make gas flow evenly from the air inlet into the second reaction flow field area (22). The distance between the air inlet and the first reaction flow field area (21) is smaller than the distance between the air inlet and the second reaction flow field area (22). The second intake distribution area (12) includes a plurality of second distribution channels (121) arranged side by side; The second reaction flow field region (22) includes a plurality of second basic flow channels (221) arranged side by side along the second direction (Y). The flow field (10) further includes a third air intake distribution zone (13) and a third reaction flow field zone (23) arranged sequentially along the first direction (X). Along the second direction (Y), the third air intake distribution zone (13) is located between the first air intake distribution zone (11) and the second air intake distribution zone (12), and is used to make the gas flow evenly from the air inlet into the third reaction flow field zone (23). The third air intake distribution area (13) includes a plurality of third distribution channels (131) arranged side by side along the second direction (Y); The third reaction flow field region (23) includes a plurality of third basic flow channels (231) arranged side by side along the second direction (Y); Each of the third distribution channels (131) is connected to P of the third basic channels (231), wherein, Each of the second distribution channels (121) includes a first branch channel (1201) and a second branch channel (1202) connected in parallel. Both the first branch channel (1201) and the second branch channel (1202) are connected to Q1 of the second basic channels (221) and satisfy the following conditions: M > P > Q1.

2. The fuel cell electrode structure according to claim 1, characterized in that, Oriented toward the center of the electrode body The lengths of the multiple first distribution channels (111) gradually increase; The lengths of the plurality of first basic channels (211) corresponding to each first distribution channel (111) gradually decrease; wherein, two of the N first basic channels (211) corresponding to the first channel (1111) are first side channels and second side channels, the second side channel being located on the side of the first side channel closer to the second channel (1112), and among the M first basic channels (211) corresponding to the second channel (1112), the first basic channel (211) closer to the second side channel is the third side channel, and the first basic channel (211) farther from the second side channel is the fourth side channel. The length of the third side channel is less than the length of the second side channel, the length of the third side channel is greater than the length of the first side channel, and the length of the fourth side channel is greater than the length of the second side channel.

3. The fuel cell electrode structure according to claim 1, characterized in that, Along the flow direction of the airflow, the first distribution channel (111) includes a first segment (101) and a second segment (102). The first segment (101) extends along the first direction (X), and the second segment (102) extends toward the center of the electrode body to communicate with the first basic channel (211) extending along the first direction (X). The first segments (101) of the plurality of first distribution channels (111) are of equal length and extend toward the center of the electrode body, while the lengths of the plurality of second segments (102) gradually increase.

4. The fuel cell electrode structure according to claim 1, characterized in that, Along the gas flow direction, the second distribution channel (121) includes a primary channel (1211) and a secondary channel (1212), wherein the primary channel (1211) connects the air inlet and the secondary channel (1212), and the secondary channel (1212) includes a first branch channel (1201) and a second branch channel (1202).

5. The fuel cell electrode structure according to claim 4, characterized in that, The primary flow channel (1211) includes a third section (103) and a fourth section (104). The third section (103) extends along a first direction (X), and the fourth section (104) is inclined toward a side away from the first air intake distribution area (11). The third sections (103) are of equal length and in the direction toward the first air intake distribution area (11), the length of the fourth section (104) gradually increases. The second basic flow channel (221) includes a fifth section (105) and a sixth section (106), the fifth section (105) extending along the first direction (X), and the sixth section (106) inclined toward one side of the first air intake distribution area (11). Both the first branch channel (1201) and the second branch channel (1202) extend along the second direction (Y). The second branch channel (1202) is located on the side of the first branch channel (1201) that is close to the second reaction flow field region (22). The length of the first branch channel (1201) is greater than the length of the second branch channel (1202).

6. The fuel cell electrode structure according to claim 1, characterized in that, The cross-sectional areas of the first basic flow channel (211), the second basic flow channel (221), and the third basic flow channel (231) are all equal.

7. The fuel cell electrode structure according to claim 1, characterized in that, The second intake distribution area (12) further includes a single flow channel (122) along the second direction (Y). The single flow channel (122) is located on the side of the second distribution channel (121) away from the first distribution channel (111). The single flow channel (122) is connected to Q2 second basic channels (221) and satisfies the following conditions: M>P>Q1≥Q2.

8. The fuel cell electrode structure according to any one of claims 1-7, characterized in that, The flow field (10) is arranged symmetrically about the geometric center point of the electrode body.

9. The fuel cell electrode structure according to claim 8, characterized in that, The flow field (10) includes an intake distribution area (1), a reaction flow field area (2), and an exhaust distribution area (3) arranged sequentially along a first direction (X). The intake distribution area (1) includes a first intake distribution area (11), a second intake distribution area (12), and a third intake distribution area (13) arranged side by side along a second direction (Y). The reaction flow field area (2) includes a first reaction flow field area (21), a second reaction flow field area (22), and a third reaction flow field area (23) arranged side by side along the second direction (Y). The exhaust distribution area (3) includes a first exhaust distribution area (31), a second exhaust distribution area (32), and a third exhaust distribution area (33) arranged side by side along the second direction (Y). Along the first direction (X), the first reaction flow field region (21) is located between the first intake distribution region (11) and the first exhaust distribution region (31), the second reaction flow field region (22) is located between the second intake distribution region (12) and the second exhaust distribution region (32), and the third reaction flow field region (23) is located between the third intake distribution region (13) and the third exhaust distribution region (33), wherein, The first intake distribution area (11) and the third exhaust distribution area (33) are arranged symmetrically about the geometric center point of the electrode body; The second intake distribution area (12) and the first exhaust distribution area (31) are arranged symmetrically about the geometric center point of the electrode body; The third air intake distribution area (13) and the second air outlet distribution area (32) are arranged symmetrically about the geometric center point of the electrode body.

10. A fuel cell single cell, characterized in that: The fuel cell comprises a membrane electrode assembly, an anode plate, and a cathode plate, wherein the cathode plate, the membrane electrode assembly, and the anode plate are stacked sequentially to form a single fuel cell, wherein the anode plate and / or the cathode plate are fuel cell electrode plate structures as described in any one of claims 1-9.

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