Polar plate structure, stack assembly, and fuel cell

Abstract

The application provides a polar plate structure, a fuel cell and a fuel cell stack assembly. The polar plate structure comprises: a first single polar plate and a second single polar plate, one of the first single polar plate and the second single polar plate is an anode plate, and the other is a cathode plate; a sealing component located between the first single polar plate and the second single polar plate; the first single polar plate has a first buffer portion arranged adjacent to the sealing component, and the first buffer portion is formed by partially bending the first single polar plate; wherein the thermal expansion coefficient of the first single polar plate is greater than the thermal expansion coefficient of the second single polar plate, the first buffer portion is located on the inner side of the sealing component close to the center of the first single polar plate, and the first buffer portion extends along the length direction of the sealing component. The application can avoid the phenomenon of sealing failure between the first single polar plate and the second single polar plate due to the different thermal expansion coefficients.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a polar plate structure, a stack assembly and a fuel cell. BACKGROUND

[0002] At present, the membrane electrode in the stack assembly is respectively provided with a cathode plate and an anode plate, the anode plate and the membrane electrode form a hydrogen flow field, and the cathode plate and the membrane electrode form an oxygen flow field. In the reaction process, the hydrogen on the anode plate side of the membrane electrode reacts to generate protons, and the protons pass through the membrane electrode to generate water with the oxygen on the cathode plate side. Since a large amount of heat will be generated in the reaction process, a sealed cooling water flow field needs to be formed between the adjacent cathode plate and anode plate through a sealing element to absorb the heat generated in the reaction process. SUMMARY

[0003] However, during the working process of the stack assembly, the inventor found that the stack assembly leaks cooling water, and replacing the sealing element between the anode plate and the anode plate or increasing the pressure of the stack cannot solve this phenomenon.

[0004] The present application provides a polar plate structure, a stack assembly and a fuel cell, which aims to solve the technical problem of the current stack assembly leaking cooling water.

[0005] In a first aspect, the present application provides a polar plate structure, comprising:

[0006] a first single polar plate and a second single polar plate, one of the first single polar plate and the second single polar plate is an anode plate, and the other is a cathode plate;

[0007] a sealing component, the sealing component is located between the first single polar plate and the second single polar plate;

[0008] the first single polar plate has a first buffer portion arranged adjacent to the sealing component, and the first buffer portion is formed by partially bending the first single polar plate;

[0009] wherein the thermal expansion coefficient of the first single polar plate is greater than the thermal expansion coefficient of the second single polar plate, the first buffer portion is located on the inner side of the sealing component close to the center of the first single polar plate, and the first buffer portion extends along the length direction of the sealing component.

[0010] In some embodiments, the first single polar plate has a first sealing step;

[0011] the first sealing step is located on the outer side of the first buffer portion away from the center of the first single polar plate, one side of the sealing component is attached to the first sealing step, and the other side is attached to the side of the second single polar plate facing the first single polar plate.

[0012] In some embodiments, the first sealing step is parallel to the second single polar plate;

[0013] The maximum distance between the first sealing step and the second single plate is greater than the maximum distance between the first bending portion and the second single plate.

[0014] In some embodiments, the second single plate has a second buffer portion opposite to the first buffer portion, the second buffer portion is formed by partially bending the second single plate;

[0015] The first buffer portion has a first deformation absorption amount, and the second buffer portion has a second deformation absorption amount, the first deformation absorption amount is greater than the second deformation absorption amount.

[0016] In some embodiments, the first buffer portion includes a plurality of first sub-bending portions, adjacent first sub-bending portions have a first elastic deformation space;

[0017] The second buffer portion includes a plurality of second sub-bending portions, adjacent second sub-bending portions have a second elastic deformation space;

[0018] The number of first sub-bending portions is greater than the number of second sub-bending portions; and / or

[0019] The first elastic deformation space along the width parallel to the first single plate is greater than the second elastic deformation space along the width parallel to the second single plate.

[0020] In some embodiments, one side of the first single plate facing the second single plate has a first shunt area, a first reaction area and a first confluence area, one side of the second single plate facing the first single plate has a second shunt area, a second reaction area and a second confluence area;

[0021] The first reaction area is located between the first shunt area and the first confluence area, and the second reaction area is located between the second shunt area and the second confluence area.

[0022] In some embodiments, the first buffer portion is located on the side of the first shunt area away from the first reaction area, and on the side of the first confluence area away from the first reaction area;

[0023] The sealing component extends along the width direction of the first single plate and is located on the side of the first shunt area away from the first reaction area, and on the side of the first confluence area away from the first reaction area.

[0024] In some embodiments, the first buffer portion is located on both sides of the first reaction area, and the sealing component extends along the length direction of the first single plate and is located on both sides of the first reaction area.

[0025] In some embodiments, the first reaction area has a plurality of first ridges arranged side by side, and adjacent first ridges have a first valley therebetween;

[0026] The second reaction area has a plurality of second ridges arranged side by side, and adjacent second ridges have a second valley therebetween;

[0027] The first ridge corresponds to the second ridge one by one, and the first valley corresponds to the second valley one by one.

[0028] In some embodiments, the length of the first ridge is equal to the length of the second ridge.

[0029] The length of the first buffer part is greater than or equal to the length of the first ridge, and the length of the sealing part is greater than or equal to the length of the first ridge.

[0030] In a second aspect, the application provides a stack assembly comprising the polar plate structure of the first aspect.

[0031] In a third aspect, the application provides a fuel cell comprising the stack assembly of the second aspect.

[0032] In the application, the first buffer part is formed on the first single polar plate with a larger thermal expansion coefficient. Since the first buffer part is located on the inner side of the sealing part close to the center of the first single polar plate, and the first buffer part extends along the length direction of the sealing part, when the working temperature of the fuel cell is high (for example, normal working), the elongation of the first single polar plate will be greater than that of the second single polar plate. At this time, the first buffer part can absorb the difference in elongation between the first single polar plate and the second single polar plate due to the difference in thermal expansion coefficient, thereby avoiding the phenomenon of cooling water leakage caused by the difference in elongation between the first single polar plate and the second single polar plate relative to the sealing part when the working temperature of the fuel cell is high. When the working temperature of the fuel cell is low (for example, cold start), the contraction of the first single polar plate will be greater than that of the second single polar plate. At this time, the first buffer part can also absorb the difference in elongation between the first single polar plate and the second single polar plate due to the difference in thermal expansion coefficient, thereby avoiding the phenomenon of cooling water leakage caused by the difference in elongation between the first single polar plate and the second single polar plate relative to the sealing part when the working temperature of the fuel cell is low. Finally, the phenomenon of sealing failure between the first single polar plate and the second single polar plate due to the difference in thermal expansion coefficient is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 is a structural schematic diagram of the polar plate structure provided in the embodiments of the application;

[0035] Figure 2 is a state schematic diagram of the polar plate structure provided in the embodiments of the application after thermal expansion;

[0036] Figure 3 is another structural schematic diagram of the polar plate structure provided in the embodiments of the present application;

[0037] Figure 4 is another structural schematic diagram of the polar plate structure provided in the embodiments of the present application;

[0038] Figure 5 is another structural schematic diagram of the polar plate structure provided in the embodiments of the present application;

[0039] Figure 6 is a structural schematic diagram of one side of the first single polar plate facing away from the second single polar plate provided in the embodiments of the present application;

[0040] Figure 7 is a structural schematic diagram of one side of the second single polar plate facing away from the first single polar plate provided in the embodiments of the present application;

[0041] Figure 8 is another structural schematic diagram of one side of the first single polar plate facing toward the second single polar plate provided in the embodiments of the present application;

[0042] Figure 9 is another structural schematic diagram of one side of the second single polar plate facing toward the first single polar plate provided in the embodiments of the present application;

[0043] Figure 10 is a structural schematic diagram of one side of the first single polar plate facing toward the second single polar plate provided in the embodiments of the present application;

[0044] Figure 11 is a structural schematic diagram of one side of the second single polar plate facing toward the first single polar plate provided in the embodiments of the present application;

[0045] Figure 12 is a structural schematic diagram of the stack assembly provided in the embodiments of the present application.

[0046] wherein, 10 is the first single polar plate, 101 is the first shunt area, 102 is the first reaction area, 103 is the first bus area, 11 is the first ridge, 12 is the first trough, 13 is the third ridge, 14 is the third trough, 15 is the first buffer part, 151 is the first sub-bending part, 152 is the first elastic deformation space, 16 is the first sealing step;

[0047] 20 is the second single polar plate, 201 is the second shunt area, 202 is the second reaction area, 203 is the second bus area, 21 is the second ridge, 22 is the second trough, 23 is the fourth ridge, 24 is the fourth trough, 25 is the second buffer part, 251 is the second sub-bending part, 252 is the second elastic deformation space, 26 is the second sealing step;

[0048] 30 is a sealing component, 40 is a membrane electrode. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0050] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0051] In the present application, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any implementation described as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, for purposes of explanation, specific details are set forth. It will be apparent to those skilled in the art that the present application can be practiced without using these specific details. In other instances, well-known structures and processes are not elaborated in order not to obscure the description of the present application with unnecessary details. Thus, the present application is not intended to be limited by the embodiments shown, but is to be accorded with the widest scope consistent with the principles and features disclosed herein.

[0052] In the prior art, since the stack assembly will generate a large amount of heat during the reaction process, a sealed cooling water flow field needs to be formed between adjacent cathode plates and anode plates by a seal to facilitate the absorption of heat generated during the reaction process. However, the inventors found that the stack assembly had a cooling water leakage phenomenon, and replacing the seal between the anode plates or increasing the stack pressure was also difficult to solve this phenomenon.

[0053] The inventors have found through deep research that, because the cathode plate is more prone to electrochemical reaction during the reaction process of the stack assembly, the cathode plate has higher requirements for corrosion resistance, and therefore different materials are usually required for the cathode plate and the anode plate. However, the cathode plate and the anode plate made of different materials have different coefficients of thermal expansion, so the elongation of the cathode plate and the anode plate is different at high temperature, or the shrinkage of the cathode plate and the anode plate is different at low temperature, which easily causes the displacement of the anode plate and the cathode plate relative to the sealant at the edge thereof to be different, and thus the phenomenon of sealing failure between the anode plate and the cathode plate occurs.

[0054] To this end, the application provides a kind of plate structure, stack assembly and fuel cell, which are described in detail below.

[0055] First, refer to Figure 1 , Figure 1 A kind of structure schematic diagram of plate structure in the embodiments of the application is shown, wherein the plate structure comprises:

[0056] The first single plate 10 and the second single plate 20, one of the first single plate 10 and the second single plate 20 is an anode plate, and the other is a cathode plate;

[0057] The sealing component 30 is located between the first single plate 10 and the second single plate 20;

[0058] The first single plate 10 has a first buffer part 15 arranged adjacent to the sealing component 30, and the first buffer part 15 is formed by partially bending the first single plate 10;

[0059] Wherein, the thermal expansion coefficient of the first single plate 10 is greater than the thermal expansion coefficient of the second single plate 20, the first buffer part 15 is located on the inner side of the sealing component 30 close to the center of the first single plate 10, and the first buffer part 15 extends along the length direction of the sealing component 30.

[0060] Specifically, the first single plate 10 and the second single plate 20 are made of conductive material (such as metal or graphite), and together constitute a bipolar plate structure. Cooling water can flow between the first single plate 10 and the second single plate 20, thereby dissipating heat from the first single plate 10 and the second single plate 20. In some embodiments of the application, the first single plate 10 can be an anode plate, and the second single plate 20 can be a cathode plate. In some other embodiments of the application, the first single plate 10 can be a cathode plate, and the second single plate 20 can be an anode plate.

[0061] Taking the first monopolar plate 10 as the anode plate and the second monopolar plate 20 as the cathode plate as an example, the first monopolar plate 10 forms a cooling water flow field on the side adjacent to the second monopolar plate 20 and a gas flow field on the side away from the second monopolar plate 20; while the second monopolar plate 20 forms a cooling water flow field on the side adjacent to the first monopolar plate 10 and a gas flow field on the side away from the first monopolar plate 10. For the cooling water flow field, cooling water can flow into the cooling water flow field of the first monopolar plate 10 and the second monopolar plate 20 to cool the first monopolar plate 10 and the second monopolar plate 20. For the gas flow field, after the side of the first monopolar plate 10 away from the second monopolar plate 20 is attached to the membrane electrode 40, or after the side of the second monopolar plate 20 away from the first monopolar plate 10 is attached to the membrane electrode 40, a flow field space is formed between the first monopolar plate 10 (or the second monopolar plate 20) and the membrane electrode 40. After the reaction gas (such as hydrogen or air) is introduced into the gas flow field, it is evenly distributed on one side of the membrane electrode 40, thereby making the electrochemical reaction of the membrane electrode 40 more complete and thorough.

[0062] The sealing component 30 forms a sealing structure between the first monopolar plate 10 and the second monopolar plate 20 to prevent cooling water leakage between them. In some embodiments of this application, the sealing component 30 may form a ring-shaped sealing structure around the edges of the first monopolar plate 10 and the second monopolar plate 20. In some embodiments of this application, the sealing component 30 may be located at a portion of the edges of the first monopolar plate 10 and the second monopolar plate 20; for example, the sealing component 30 may be located between the length edges or width edges of the first monopolar plate 10 and the second monopolar plate 20.

[0063] In some embodiments of this application, the sealing component 30 may be a sealing ring / seal strip adhered to the first monopolar plate 10 or the second monopolar plate 20. For example, the sealing ring / seal strip may be formed by injection molding the first monopolar plate 10 as a component of the injection mold, thereby achieving pre-fixation of the sealing component 30. In some embodiments of this application, the sealing component 30 may be a sealing ring / seal strip clamped between the first monopolar plate 10 and the second monopolar plate 20.

[0064] Understandably, the sealing component 30 can also be integrally formed with the first monopolar plate 10 or the second monopolar plate 20, for example, by stamping the edge of the second monopolar plate 20 to form the sealing component 30.

[0065] In the embodiments of the present application, the first buffer part 15 is formed by bending the first single plate 10 with a larger thermal expansion coefficient. Since the first buffer part 15 is located on the inner side of the sealing part 30 close to the center of the first single plate 10 and extends along the length direction of the sealing part 30, when the working temperature of the fuel cell is high (for example, normal working), the elongation of the first single plate 10 will be greater than that of the second single plate 20. At this time, the first buffer part 15 can absorb the difference in elongation between the first single plate 10 and the second single plate 20 due to the difference in thermal expansion coefficient, thereby avoiding the phenomenon of cooling water leakage due to the difference in elongation between the first single plate 10 and the second single plate 20 relative to the sealing part 30 when the working temperature of the fuel cell is high. When the working temperature of the fuel cell is low (for example, cold start), the contraction of the first single plate 10 will be greater than that of the second single plate 20. At this time, the first buffer part 15 can also absorb the difference in elongation between the first single plate 10 and the second single plate 20 due to the difference in thermal expansion coefficient, thereby avoiding the phenomenon of cooling water leakage due to the difference in elongation between the first single plate 10 and the second single plate 20 relative to the sealing part 30 when the working temperature of the fuel cell is low. Finally, the phenomenon of sealing failure between the first single plate 10 and the second single plate 20 due to the difference in thermal expansion coefficient is avoided.

[0066] In some embodiments of the present application, for example, for the embodiments in which the sealing part 30 is located between the length edges or the width edges of the first single plate 10 and the second single plate 20, the first buffer part 15 can be located at the length edge or the width edge of the first single plate 10 and extend along the length direction or the width direction of the first single plate 10. In some embodiments of the present application, the first buffer part 15 can also be arranged in a circle around the edge of the first single plate 10.

[0067] In some embodiments of the present application, continuing to refer to Figure 1 , the first single plate 10 has a first sealing step 16; the first sealing step 16 is located on the outer side of the first buffer part 15 away from the center of the first single plate 10, one side of the sealing part 30 is attached to the first sealing step 16, and the other side is attached to the side of the second single plate 20 facing the first single plate 10. Specifically, the first sealing step 16 can provide a flat sealing surface for the sealing part 30, thereby ensuring the sealing between the sealing part 30 and the first single plate 10.

[0068] Further, in some embodiments of the present application, continuing to refer to Figure 1 and Figure 2 , Figure 2A state diagram showing the thermal expansion of the polar plate structure in the embodiment of the present application is shown, in which the first sealing step 16 is parallel to the second single polar plate 20, and the maximum distance H1 between the first sealing step 16 and the second single polar plate 20 is greater than the maximum distance H2 between the first bending part and the second single polar plate 20.

[0069] It should be noted that, since the maximum distance between the first sealing step 16 and the second single polar plate 20 is greater than the maximum distance between the first bending part and the second single polar plate 20, the first sealing step 16 is closer to the second single polar plate 20, and the first buffer part 15 is formed by bending the first single polar plate 10 partially towards the second single polar plate 20. When the first single polar plate 10 is thermally expanded, the first buffer part 15 absorbs and buffers the deformation of the first single polar plate 10, and at the same time, the deformation of the first buffer part 15 will cause the first sealing step 16 to tilt and press the sealing member 30 from the outside to the inside, so that the sealing member 30 has a higher pressure with the first sealing step 16, thereby achieving the purpose of strengthening the sealing performance of the sealing member 30 by the thermal expansion deformation of the polar plate structure. Figure 2

[0070] It can be understood that, as shown in Figure 3 , Figure 3 Another structural diagram of the polar plate structure in the embodiment of the present application is shown, in which the maximum distance between the first sealing step 16 and the second single polar plate 20 can also be less than the maximum distance between the first bending part and the second single polar plate 20. When the first single polar plate 10 is thermally expanded, the deformation of the first buffer part 15 will cause the first sealing step 16 to tilt and press the sealing member 30 from the inside to the outside.

[0071] Further, in some embodiments of the present application, referring back to Figure 4 , Figure 4 Another structural diagram of the polar plate structure in the embodiment of the present application is shown, in which the second single polar plate 20 has a second buffer part 25 opposite to the first buffer part 15, and the second buffer part 25 is formed by bending the second single polar plate 20 partially; the first buffer part 15 has a first deformation absorption amount, and the second buffer part 25 has a second deformation absorption amount, and the first deformation absorption amount is greater than the second deformation absorption amount.

[0072] ​It should be noted that the first deformation absorption amount refers to the deformation amount of the first monopolar plate 10 that can be absorbed by the first buffer portion 15 due to thermal expansion, and the second deformation absorption amount refers to the deformation amount of the second monopolar plate 20 that can be absorbed by the second buffer portion 25 due to thermal expansion; for example, the first monopolar plate 10 with the first buffer portion 15 and the first monopolar plate 10 without the first buffer portion 15 can be placed at the same ambient temperature, and the difference in deformation amount of the two first monopolar plates 10 can be measured to obtain the first deformation absorption amount; similarly, for the second deformation absorption amount, the second monopolar plate 20 with the second buffer portion 25 and the second monopolar plate 20 without the second buffer portion 25 can be placed at the same ambient temperature, and the difference in deformation amount of the two second monopolar plates 20 can be measured to obtain the second deformation absorption amount.

[0073] In the above embodiment, since the first deformation absorption amount is greater than the second deformation absorption amount, and the elongation amount of the first monopolar plate 10 after thermal expansion is greater than the elongation amount of the second monopolar plate 20 after thermal expansion, the first buffer portion 15 can absorb more of the elongation amount of the first monopolar plate 10 after thermal expansion, thereby reducing the difference in elongation amount between the first monopolar plate 10 and the second monopolar plate 20 due to the difference in thermal expansion coefficient, and ultimately achieving the purpose of avoiding sealing failure between the first monopolar plate 10 and the second monopolar plate 20 due to the difference in thermal expansion coefficient.

[0074] In some embodiments of the present application, as shown in Figure 4 The second monopolar plate 20 has a second sealing step 26; the second sealing step 26 is located on the outer side of the second buffer portion 25 away from the center of the second monopolar plate 20, and the sealing member 30 is in contact with the first sealing step 16 on one side and in contact with the second sealing step 26 on the other side, so as to ensure the sealing between the sealing member 30 and the first monopolar plate 10 and the second monopolar plate 20.

[0075] In some embodiments of the present application, the first buffer portion 15 has a first deformation compensation amount, and the second buffer portion 25 has a second deformation compensation amount, and the first deformation compensation amount is greater than the second deformation compensation amount.

[0076] It should be noted that the first deformation compensation amount refers to the deformation amount of the first monopolar plate 10 that can be compensated by the first buffer portion 15 due to cold shrinkage, and the second deformation compensation amount refers to the deformation amount of the second monopolar plate 20 that can be compensated by the second buffer portion 25 due to cold shrinkage; for example, the first monopolar plate 10 with the first buffer portion 15 and the first monopolar plate 10 without the first buffer portion 15 can be placed at the same ambient temperature, and the difference between the cold deformation amounts of the two first monopolar plates 10 can be measured to obtain the first deformation compensation amount; similarly, for the second deformation compensation amount, the second monopolar plate 20 with the second buffer portion 25 and the second monopolar plate 20 without the second buffer portion 25 can be placed at the same ambient temperature, and the difference between the cold deformation amounts of the two second monopolar plates 20 can be measured to obtain the second deformation compensation amount.

[0077] In the above embodiment, since the first deformation compensation amount is greater than the second deformation compensation amount, and the shrinkage amount of the first monopolar plate 10 after cold shrinkage is greater than the shrinkage amount of the second monopolar plate 20 after cold shrinkage, the first buffer portion 15 can compensate more for the shrinkage amount of the first monopolar plate 10 after cold shrinkage, thereby reducing the difference in cold shrinkage amount between the first monopolar plate 10 and the second monopolar plate 20 due to the difference in thermal expansion coefficient.

[0078] As an example, refer to Figure 5 , Figure 5 Another structure of the monopolar plate structure in the embodiment of the application is shown, wherein the first buffer portion 15 includes a plurality of first sub-bending portions 151, adjacent first sub-bending portions 151 have a first elastic deformation space 152; the second buffer portion 25 includes a plurality of second sub-bending portions 251, adjacent second sub-bending portions 251 have a second elastic deformation space 252, and the number of first sub-bending portions 151 is greater than the number of second sub-bending portions 251.

[0079] In the above embodiment, the plurality of first sub-bending portions 151 form a first buffer portion 15 similar to a spring, when a part of the first monopolar plate 10 (for example, a reaction area) is heated and expanded, the plurality of first sub-bending portions 151 are adjacent to each other and reduce the first elastic deformation space 152, thereby absorbing the elongation amount generated by the heat expansion of the first monopolar plate 10; similarly, the plurality of second sub-bending portions 251 form a second buffer portion 25 similar to a spring, when a part of the second monopolar plate 20 (for example, a reaction area) is heated and expanded, the plurality of second sub-bending portions 251 are adjacent to each other and reduce the second elastic deformation space 252, thereby absorbing the elongation amount generated by the heat expansion of the second monopolar plate 20. At the same time, since the number of first sub-bending portions 151 is greater than the number of second sub-bending portions 251, the first deformation absorption amount of the first buffer portion 15 is greater than the second deformation absorption amount of the second buffer portion 25.

[0080] It can be understood that when the first single pole plate 10 and the second single pole plate 20 are cold shrinkage, and due to the number of the first sub-bending part 151 is greater than the number of the second sub-bending part 251, the first deformation compensation amount of the first buffer part 15 can be greater than the second deformation compensation amount of the second buffer part 25, thereby reducing the difference in cold shrinkage amount of the first single pole plate 10 and the second single pole plate 20 due to the difference in thermal expansion coefficient.

[0081] It should be noted that in addition to changing the number of the first sub-bending part 151 and the number of the second sub-bending part 251, the first deformation absorption amount of the first buffer part 15 can be greater than the second deformation absorption amount of the second buffer part 25 by other means, for example, the first elastic deformation space 152 is arranged along the width of the first single pole plate 10 to be greater than the second elastic deformation space 252 along the width of the second single pole plate 20, when the first single pole plate 10 and the second single pole plate 20 are hot expansion, the compression amount of adjacent first sub-bending part 151 can be greater, thereby making the first deformation absorption amount of the first buffer part 15 greater than the second deformation absorption amount of the second buffer part 25; for example, the first buffer part 15 can be composed of a single first sub-bending part 151, and the second buffer part 25 can be composed of a single second sub-bending part 251, so that the inclination of the first sub-bending part 151 is less than the inclination of the second sub-bending part 251, that is, the first deformation absorption amount of the first buffer part 15 is greater than the second deformation absorption amount of the second buffer part 25.

[0082] In some embodiments of the present application, continue to refer to Figure 6 and Figure 7 , Figure 6 shows a structure schematic diagram of one side of the first single pole plate 10 towards the second single pole plate 20 in the embodiments of the present application, Figure 7 shows a structure schematic diagram of one side of the second single pole plate 20 towards the first single pole plate 10 in the embodiments of the present application, wherein one side of the first single pole plate 10 towards the second single pole plate 20 has a first shunt area 101, a first reaction area 102 and a first confluence area 103, and one side of the second single pole plate 20 towards the first single pole plate 10 has a second shunt area 201, a second reaction area 202 and a second confluence area 203; the first reaction area 102 is located between the first shunt area 101 and the first confluence area 103, and the second reaction area 202 is located between the second shunt area 201 and the second confluence area 203.

[0083] Specifically, the first reaction area 102 and the second reaction area 202 refer to the areas where the first monopolar plate 10 and the second monopolar plate 20 generate reactions. Generally, the first reaction area 102 and the second reaction area 202 can be the areas of the membrane electrode 40 active area opposite to the first monopolar plate 10 and the second monopolar plate 20, or the first reaction area 102 and the second reaction area 202 can refer to the areas having uniformly arranged flow channels; and the first shunt area 101 and the second shunt area 201 are used to disperse the cooling water so as to uniformly enter the first reaction area 102 of the first monopolar plate 10 or the second reaction area 202 of the second monopolar plate 20; and the first collecting area 103 and the second collecting area 203 can collect the cooling water so as to concentrate and discharge the cooling water.

[0084] In some embodiments of the present application, the first buffer part 15 is located on both sides of the first reaction area 102, and the sealing part 30 extends along the length direction of the first monopolar plate 10 and is located on both sides of the first reaction area 102.

[0085] It should be noted that, since the first monopolar plate 10 and the second monopolar plate 20 generate heat during the fuel cell reaction, the areas where the first monopolar plate 10 and the second monopolar plate 20 generate heat are mainly in the first reaction area 102 and the second reaction area 202, and the flow channels of the first monopolar plate 10 and the second monopolar plate 20 generally extend along the length direction thereof. Since the thermal expansion deformation of the first monopolar plate 10 and the second monopolar plate 20 mainly manifests as expansion deformation along the width direction thereof, such thermal expansion deformation will cause the cooling water leakage to mainly occur at the length edges of the first monopolar plate 10 and the second monopolar plate 20. In the above embodiments, by arranging the sealing part 30 to extend along the length direction of the first monopolar plate 10 and be located on both sides of the first reaction area 102, the sealing of the length edges of the first monopolar plate 10 and the second monopolar plate 20 can be enhanced, thereby avoiding the phenomenon of cooling water leakage at the length edges of the first monopolar plate 10 and the second monopolar plate 20. Meanwhile, since the first buffer part 15 is also located on both sides of the first reaction area 102 and extends along the length direction of the first monopolar plate 10, the first buffer part 15 can better absorb the deformation of the first monopolar plate 10 along the width direction thereof, thereby reducing the deformation difference between the first monopolar plate 10 and the second monopolar plate 20.

[0086] In some embodiments of the present application, continuing to refer to Figure 8 and Figure 9 , Figure 8 Fig. 4 shows another structural schematic view of the first monopolar plate 10 facing the second monopolar plate 20 in the embodiments of the present application, Figure 9Fig. 6 shows another schematic view of the one side of the second single polar plate 20 facing the first single polar plate 10 in the embodiment of the present application, wherein the first buffer part 15 is located at the side of the first flow separation area 101 away from the first reaction area 102 and at the side of the first flow convergence area 103 away from the first reaction area 102; and the sealing part 30 extends along the width direction of the first single polar plate 10 and is located at the side of the first flow separation area 101 away from the first reaction area 102 and at the side of the first flow convergence area 103 away from the first reaction area 102.

[0087] It should be noted that the first single polar plate 10 and the second single polar plate 20 will deform along the length direction in addition to the width direction, and in the above embodiment, the first buffer part 15 can also be arranged at both ends of the first single polar plate 10 along the length direction, and the sealing part 30 can also be arranged at both ends of the first single polar plate 10 along the length direction, so as to avoid the leakage of cooling water and the difference in deformation at the width edges of the first single polar plate 10 and the second single polar plate 20.

[0088] It can be understood that in addition to the sealing part 30, a whole-circle sealing ring structure can also be arranged between the first single polar plate 10 and the second single polar plate 20, so as to mainly strengthen the sealing effect of the length edges of the first single polar plate 10 and the second single polar plate 20 by the sealing part 30.

[0089] In some embodiments of the present application, continuing to refer to Figure 1 , Figure 6 and Figure 7 , wherein the first reaction area 102 has a plurality of first ridges 11 arranged side by side, and a first valley 12 is arranged between adjacent first ridges 11; the second reaction area 202 has a plurality of second ridges 21 arranged side by side, and a second valley 22 is arranged between adjacent second ridges 21; the first ridges 11 and the second ridges 21 are one-to-one corresponding, and the first valleys 12 and the second valleys 22 are one-to-one corresponding.

[0090] It should be noted that the first ridges 11 and the first valleys 12 of the first single polar plate 10 form a cooling water flow field, and the second valleys 22 and the second ridges 21 of the cathode plate form a cooling water flow field, the first valley 12 is a cooling water flow channel of the first single polar plate 10, and the second valley 22 is a cooling water flow channel of the second single polar plate 20. Due to the existence of the ridges and valleys of the first single polar plate 10 and the second single polar plate 20, the difference in thermal expansion deformation of the first single polar plate 10 and the second single polar plate 20 will be more obvious at the corresponding positions of the first ridges 11 / second ridges 21 when the fuel cell is deformed at high temperature, and the sealing failure phenomenon caused by the difference in thermal expansion deformation of the ridges and valleys of the first single polar plate 10 and the second single polar plate 20 can be avoided by arranging the first buffer part 15 on the first single polar plate 10.

[0091] Preferably, the length of the first ridge 11 is equal to the length of the second ridge 21, the length of the first buffer portion 15 is greater than or equal to the length of the first ridge 11, and the length of the sealing member 30 is greater than or equal to the length of the first ridge 11, so that the first buffer portion 15 can fully absorb the deformation at the first reaction zone 102, and the sealing member 30 can better seal both sides of the first reaction zone 102 to prevent local cooling water leakage in the first reaction zone 102.

[0092] In some embodiments of this application, see further reference. Figure 10 , Figure 10 A schematic diagram of the structure of the first monopolar plate 10 facing away from the second monopolar plate 20 in an embodiment of this application is shown. The first monopolar plate 10 facing away from the second monopolar plate 20 also has a third ridge 13, and there is a third valley 14 between adjacent third ridges 13. The third ridge 13 corresponds to the first valley 12, and the third valley 14 corresponds to the first ridge 11.

[0093] Specifically, since the third ridge 13 corresponds to the first valley 12 and the third valley 14 corresponds to the first ridge 11, when the first valley 12 is formed by stamping the side of the first monopole plate 10 adjacent to the second monopole plate 20, the third ridge 13 is formed on the side of the first monopole plate 10 away from the second monopole plate 20. At the same time, after the first valley 12 is formed by stamping, the two sides of the first valley 12 are the first ridge 11, and the first ridge 11 on one side of the first monopole plate 10 corresponds to the third valley 14 on the other side. Therefore, the formation of the first valley 12, the first ridge 11, the third valley 14 and the third ridge 13 on the first monopole plate 10 only requires the formation of the first valley 12 by stamping. This not only simplifies the processing steps of the first monopole plate 10, but also reduces the thickness of the first monopole plate 10, which is beneficial to increasing the number of single cells and the cell density per unit volume of the fuel cell stack.

[0094] It is understandable that the first concave valley 12 and the first convex ridge 11 can be formed on one side of the first monopolar plate 10 by processing (e.g., milling), while the third concave valley 14 and the third convex ridge 13 can be formed on the other side by further processing.

[0095] In some embodiments of this application, see further reference. Figure 11 , Figure 11 A schematic diagram of the structure of the second monopolar plate 20 facing away from the first monopolar plate 10 in an embodiment of this application is shown. The second monopolar plate 20 facing away from the first monopolar plate 10 also has a fourth ridge 23, and there is a fourth valley 24 between adjacent fourth ridges 23. The fourth ridge 23 corresponds to the second valley 22, and the fourth valley 24 corresponds to the second ridge 21.

[0096] Specifically, since the fourth ridge 23 corresponds to the second valley 22, and the fourth valley 24 corresponds to the second ridge 21, when the second valley 22 is punched on the side of the second monopolar plate 20 facing the first monopolar plate 10, that is, the fourth ridge 23 is formed on the side of the second monopolar plate 20 away from the first monopolar plate 10, and after the second valley 22 is punched, the second ridge 21 is formed on both sides of the second valley 22, and the second ridge 21 on one side of the second monopolar plate 20 corresponds to the fourth valley 24 on the other side, therefore, the second monopolar plate 20 only needs to be punched to form the second valley 22 to form the second valley 22, the second ridge 21, the fourth valley 24 and the fourth ridge 23 of the second monopolar plate 20, which not only simplifies the processing procedure of the second monopolar plate 20, but also reduces the thickness of the second monopolar plate 20, which is conducive to improving the number of single cells and the cell density in a unit volume of the fuel cell stack.

[0097] It can be understood that the second valley 22 and the second ridge 21 can also be formed on one side of the second monopolar plate 20 by machining (such as milling), and the fourth valley 24 and the fourth ridge 23 can also be formed on the other side by machining.

[0098] It is worth noting that the above description of the monopolar plate structure is intended to clearly illustrate the implementation of the application, and those skilled in the art can also make equivalent modifications and designs under the guidance of the application, for example, the first monopolar plate 10 and the second monopolar plate 20 are regular hexagons, and the sealing member 30 is arranged on the four edges on both sides of the first monopolar plate 10.

[0099] Further, in order to better implement the monopolar plate structure in the embodiments of the application, on the basis of the monopolar plate structure, the application further provides a stack assembly, which is described below with reference to Figure 12 , Figure 12 Fig. 1 shows a structural schematic diagram of a stack assembly in an embodiment of the application, wherein the stack assembly comprises a membrane electrode 40 and a plurality of monopolar plate structures as in any of the above embodiments, and the membrane electrode 40 is located between adjacent monopolar plate structures. Since the stack assembly in the embodiment of the application is provided with the monopolar plate structure in the above embodiments, it has all the beneficial effects of the monopolar plate structure, which will not be described here again.

[0100] Further, in order to better implement the stack assembly in the embodiments of the application, on the basis of the stack assembly, the application further provides a fuel cell, which comprises the stack assembly as in any of the above embodiments. Since the fuel cell in the embodiment of the application is provided with the monopolar plate structure in the above embodiments, it has all the beneficial effects of the monopolar plate structure, which will not be described here again.

[0101] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be seen in the detailed description of the other embodiments above, which will not be described here again.

[0102] The foregoing detailed description has set forth various embodiments of the application via the use of specific terminology. As is understood by those skilled in the art, the application is not intended to be limited to the particulars described, but is to be understood as encompassing all modifications, alterations, and permutations of the technology disclosed herein that fall within the scope and spirit of the application. Although specific terms have been employed herein, these are used in a generic and descriptive sense only and not for purposes of limitation.

[0103] Also, the use of "one embodiment," "an embodiment," "some embodiments," "one implementation," "an implementation," "some implementations," "one alternative," "an alternative," "some alternatives" and "another alternative" are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or characteristic described in connection with these terms can be included in the described present application. It is further noted that the features, structures, or characteristics can be combined in any suitable manner in one or more implementations.

[0104] It is to be understood that the phraseology or terminology employed herein, and not otherwise expressly stated, is intended to be interpreted in accordance with the principles of the patent law. It is further noted that the use of "a" or "an", that can be interpreted as the "one and only one", does not exclude other instances of the same feature occurring in the application. Similarly, as used herein, the conjunctive use of terms such as "at least one of or "one or more of, when used in the context of examples of a feature, quantity, characteristic, parameter or the like, are intended to convey the inclusion of at least one, but also the possibility of including more than one of the listed features or quantities.

[0105] Some embodiments use numerical ranges to describe quantities of components, attributes, etc. It should be understood that such numerical ranges described in the embodiments are, in some examples, modified by the word "about". Unless otherwise indicated, the word "about" means ±20% of the value of the range. Accordingly, any numerical parameters such as those included in the application and claims are approximations. At the very least, these numerical parameters and values should be construed in light of the

[0106] For each patent, patent application, patent application publication, and other material such as articles, books, specifications, publications, and documents referenced in this application, the entire contents of that patent application are incorporated herein by reference, except for historical application documents that are inconsistent with or conflict with the content of this application, and documents that limit the broadest scope of the claims of this application (currently or subsequently appended to this application). It should be noted that if there are any inconsistencies or conflicts between the descriptions, definitions, and / or terminology used in the supplementary materials of this application and the content of this application, the descriptions, definitions, and / or terminology used in this application shall prevail.

[0107] The above provides a detailed description of the electrode structure, stack assembly, and fuel cell provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An electrode structure, characterized in that, include: A first monopole plate and a second monopole plate, wherein one of the first monopole plate and the second monopole plate is an anode plate and the other is a cathode plate; A sealing component, wherein the sealing component is located between the first monopolar plate and the second monopolar plate; The first monopolar plate has a first buffer portion disposed adjacent to the sealing component, the first buffer portion being formed by bending a portion of the first monopolar plate; Wherein, the coefficient of thermal expansion of the first monopolar plate is greater than that of the second monopolar plate, the first buffer portion is located on the inner side of the sealing component near the center of the first monopolar plate, and the first buffer portion extends along the length direction of the sealing component. The first monopolar plate has a first sealing step, which is located on the outer side of the first buffer portion away from the center of the first monopolar plate. One side of the sealing component is in contact with the first sealing step, and the other side is in contact with the side of the second monopolar plate facing the first monopolar plate. The first sealing step is parallel to the second monopolar plate, and the maximum distance between the first sealing step and the second monopolar plate is less than the maximum distance between the first buffer part and the second monopolar plate.

2. The electrode structure as described in claim 1, characterized in that, The second monopolar plate has a second buffer portion opposite to the first buffer portion, and the second buffer portion is formed by bending a portion of the second monopolar plate; The first buffer portion has a first deformation absorption amount, and the second buffer portion has a second deformation absorption amount, wherein the first deformation absorption amount is greater than the second deformation absorption amount.

3. The electrode structure as described in claim 2, characterized in that, The first buffer portion includes a plurality of first sub-bending portions, and adjacent first sub-bending portions have a first elastic deformation space; The second buffer section includes a plurality of second sub-bending sections, and adjacent second sub-bending sections have a second elastic deformation space; The number of the first sub-bends is greater than the number of the second sub-bends; and / or The width of the first elastic deformation space parallel to the first monopolar plate is greater than the width of the second elastic deformation space parallel to the second monopolar plate.

4. The electrode structure as described in claim 1, characterized in that, The side of the first monopolar plate facing the second monopolar plate has a first shunt region, a first reaction region, and a first busbar region, and the side of the second monopolar plate facing the first monopolar plate has a second shunt region, a second reaction region, and a second busbar region. The first reaction zone is located between the first diversion zone and the first confluence zone, and the second reaction zone is located between the second diversion zone and the second confluence zone.

5. The electrode structure as described in claim 4, characterized in that, The first buffer portion is located on both sides of the first reaction zone, and the sealing component extends along the length of the first monopolar plate and is located on both sides of the first reaction zone.

6. The electrode structure as described in claim 5, characterized in that, The first buffer section is located on the side of the first diversion area away from the first reaction area, and the first confluence area is located on the side of the first reaction area away from the first reaction area; The sealing component extends along the width direction of the first monopolar plate and is located on the side of the first shunt region away from the first reaction region, and on the side of the first convergence region away from the first reaction region.

7. A fuel cell stack assembly, characterized in that, Includes the electrode structure as described in any one of claims 1 to 6.

8. A fuel cell, characterized in that, Includes the fuel cell stack assembly as described in claim 7.

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