Fuel cell stack binding device and method

Abstract

The invention relates to a fuel cell stack tightening device and method. The fuel cell stack tightening device comprises a first mounting piece and a second mounting piece, the second mounting part is arranged opposite to the first mounting part; the multiple limiting supporting pieces are fixedly connected with the first mounting piece, and threaded holes extending in the extending direction of the limiting supporting pieces are formed in the limiting supporting pieces; the plurality of threaded pull rods are rotatably connected and matched with the threaded pull rods in a penetrating manner, the first mounting piece is provided with external threads, and the threaded pull rods are connected with the corresponding limiting supporting pieces through the threaded holes and the external threads in a matched manner; wherein the first mounting piece, the second mounting piece, the limiting supporting piece and the threaded pull rod define an accommodating cavity for accommodating the electric pile. The total length of the limiting supporting piece and the threaded pull rod can be adjusted by relatively rotating the limiting supporting piece and the threaded pull rod, so that the relative distance between the first mounting piece and the second mounting piece is adjusted, the device can adapt to the height change of a galvanic pile in the accommodating cavity, and the device is more flexible to use and has better universality.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a fuel cell stack binding device and method. Background Art

[0002] With the development of the times, hydrogen energy, as an important member of future clean energy, has received widespread attention. Fuel cells, as an important terminal application scenario of hydrogen energy, have been extensively studied by relevant researchers. Fuel cells are a device that directly converts the chemical energy of fuel into electrical energy. Its core device, the stack, is usually composed of alternating stacks of membrane electrodes (MEAs) and bipolar plates.

[0003] Fuel cells have a wide range of applications in heavy machinery such as heavy trucks. However, due to the large load and high power requirements of heavy machinery such as heavy trucks, the entire fuel cell stack needs to contain more single cells to meet the requirements of high power output.

[0004] During the stacking process of the fuel cell stack, the compression of the stack press will cause the height of the entire stack to begin to deform. The deformation height of the stack is closely related to the size of the stack pressing force, and the deformation of the stack is also affected by many other factors such as:

[0005] Number of single cells: The more single cells there are, the higher the total height of the battery stack will be, and the deformation will increase accordingly.

[0006] Compacting force: The size of the compressing force directly affects the deformation height of the fuel cell stack. Excessive compressing force may cause excessive compression of the fuel cell stack, affecting its performance and structural integrity.

[0007] Material properties of bipolar plates and membrane electrodes: The material properties of bipolar plates and membrane electrodes (such as stiffness, elastic modulus, etc.) will affect the deformation characteristics of the fuel cell stack.

[0008] Due to the complex interaction of these factors, the final deformation height of the stack after compaction is difficult to accurately assess before stacking. Therefore, the stack binding mechanism needs to be able to adapt to this height change to ensure the stability and reliability of the stack after compaction.

[0009] At present, common fuel cell stack fastening devices can only be used for stacks of fixed height and cannot meet the changes in stack height. This limits the flexibility and reliability of the stack in practical applications, especially in scenarios such as heavy trucks that require high power output. Summary of the invention

[0010] Based on this, the present application provides a fuel cell stack binding device and method to meet the changes in the stack compression height.

[0011] The present application provides a fuel cell stack binding device, including: a first mounting member; a second mounting member, which is arranged opposite to the first mounting member; a plurality of limit support members, which are fixedly connected to the first mounting member, the plurality of limit support members are arranged along the circumference of the first mounting member, and all extend toward the second mounting member, and the limit support member is provided with a threaded hole extending along the extension direction of the limit support member at one end facing the second mounting member; a plurality of threaded pull rods, which are rotatably connected and matched with the threaded pull rods and extend toward the first mounting member, the first mounting member is provided with external threads, and the plurality of threaded pull rods correspond to the plurality of limit support members respectively, and the threaded pull rods are connected to the corresponding limit support members through the threaded holes and the external threads; wherein, a housing cavity for accommodating the fuel cell stack is surrounded by the first mounting member, the second mounting member, the limit support member and the threaded pull rods.

[0012] According to one embodiment of the present application, the plurality of limit supports are symmetrically arranged with respect to a first plane, the plurality of limit supports located on the same side of the first plane are arranged in sequence along a direction parallel to the first plane, and the plurality of limit supports located on the same side of the first plane are in contact and cooperation with corresponding sides of the fuel cell stack; wherein the first plane is parallel to the extension direction of the limit supports and the threaded pull rod.

[0013] According to one embodiment of the present application, the fuel cell stack binding device also includes: a plurality of locking members, which are disposed at the connection positions of the plurality of the limiting supports and the plurality of the threaded tie rods, and the locking members are respectively connected to the corresponding limiting supports and the threaded tie rods to lock the relative positions of the limiting supports and the threaded tie rods; or, the limiting supports and the threaded tie rods are welded and fixed; or, the limiting supports and the threaded tie rods are adhesively fixed.

[0014] According to one embodiment of the present application, the locking member includes a threaded member, a rivet member or a locking pin, and the locking member is simultaneously connected and cooperated with the limiting support member and the threaded pull rod.

[0015] According to one embodiment of the present application, the limiting support member is provided with a first through hole, the threaded pull rod is provided with a plurality of second through holes, and the plurality of second through holes are arranged along the extension direction of the threaded pull rod; the locking member is located in the first through hole, and can be selectively provided in any of the second through holes.

[0016] According to one embodiment of the present application, it also includes: a floating member, which is movably arranged in the accommodating cavity and abuts against one end of the battery stack facing the first mounting member; at least one elastic member, the elastic member includes a butterfly spring, a coil spring, and a leaf spring. The present application also provides any combination of one or more of the two, and the elastic member is elastically supported between the first mounting member and the floating member.

[0017] According to one embodiment of the present application, a surface of at least one of the first mounting member, the second mounting member, the limiting support member, the threaded pull rod and the floating member is provided with an insulating material layer.

[0018] According to one embodiment of the present application, the battery stack includes a plurality of stacked single cells, and the stacking direction of the plurality of single cells is parallel to the extension direction of the limiting support and the threaded pull rod; in a stacking direction perpendicular to the single cells, the relative offset between any two of the plurality of single cells is less than or equal to 0.5 mm; and or, the stacking force of the plurality of single cells along the stacking direction of the single cells is greater than 0.6 MPa and less than 1.5 MPa.

[0019] The present application also provides a fuel cell stack binding method, which is applied to the fuel cell stack binding device of the above-mentioned embodiment, and the method includes: stacking all the single cells of the stack between a first mounting member and a second mounting member; applying a preset pressure to the first mounting member and the second mounting member to bring them closer to each other; and threading the threaded pull rod to the limiting support member.

[0020] According to one embodiment of the present application, it also includes: determining the material property parameters of the single cell based on the geometric parameters, morphological parameters, fractal parameters and conductivity of the single cell, and determining the theoretical minimum stacking force based on the material property parameters of the single cell, the contact resistance and contact area between each single cell, and the number of the single cells in the stack; determining the theoretical maximum stacking force based on the battery working fluid transmission characteristic parameters and the battery structure strength requirement parameters; the preset pressure is greater than or equal to the theoretical minimum stacking force, and less than or equal to the maximum stacking force.

[0021] The above-mentioned fuel cell stack binding device and method have threaded cooperation between the limit support member and the threaded pull rod. By relative rotation of the limit support member and the threaded pull rod, the total length of the limit support member and the threaded pull rod can be adjusted, and then the relative distance between the first mounting member and the second mounting member can be adjusted. It can adapt to the height change of the fuel cell stack located in the accommodating cavity, is more flexible to use, and has better versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a fuel cell stack binding device provided in this application.

[0023] Figure 2 An exploded view of a fuel cell stack binding device provided in this application.

[0024] Figure 3 A schematic diagram of the connection relationship between a first mounting member and a limiting support member in a fuel cell stack binding device provided in the present application.

[0025] Figure 4 A schematic diagram of the stacking method of single cells in a fuel cell stack binding device provided in the present application.

[0026] Figure 5 A flow chart of a fuel cell stack binding method provided in the present application.

[0027] Reference numerals:

[0028] 1. Second mounting part; 2. Upper insulating plate; 3. Upper current collecting plate; 4. Threaded pull rod; 5. Battery stack; 6. Limit support member; 7. Locking member; 8. Lower current collecting plate; 9. Lower insulating plate; 10. Floating member; 11. Elastic member; 12. First mounting part. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0030] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is the orientation or position relationship based on the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0032] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0033] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0035] Figure 1 A schematic diagram of the structure of a fuel cell stack binding device provided in this application; Figure 2 An exploded view of a fuel cell stack binding device provided in this application; Figure 3 A schematic diagram of the connection relationship between a first mounting member 12 and a limiting support member 6 in a fuel cell stack binding device provided in the present application; Figure 4A schematic diagram of the stacking method of single cells in a fuel cell stack binding device provided in the present application.

[0036] like Figures 1 to 4 As shown, a fuel cell stack binding device provided in an embodiment of the present application includes a first mounting member 12, a second mounting member 1, a plurality of position limiting supports 6 and a plurality of threaded tie rods 4. The second mounting member 1 is arranged opposite to the first mounting member 12. A plurality of position limiting supports 6 are fixedly connected to the first mounting member 12, and the plurality of position limiting supports 6 are arranged along the circumference of the first mounting member 12, and all extend toward the second mounting member 1, and a threaded hole extending along the extension direction of the position limiting support 6 is provided at one end of the position limiting support 6 facing the second mounting member 1. A plurality of threaded tie rods 4 are rotatably connected and matched with the threaded tie rods 4, and extend toward the first mounting member 12, and the first mounting member 12 is provided with external threads, and a plurality of threaded tie rods 4 correspond to a plurality of position limiting supports 6 respectively, and the threaded tie rods 4 are connected to the corresponding position limiting supports 6 through threaded holes and external threads. Among them, a receiving cavity for accommodating the stack 5 is surrounded by the first mounting member 12, the second mounting member 1, the position limiting support 6 and the threaded tie rods 4.

[0037] The fuel cell stack binding device of the present embodiment has a threaded fit between the limit support member 6 and the threaded tie rod 4. By relative rotation of the limit support member 6 and the threaded tie rod 4, the total length of the limit support member 6 and the threaded tie rod 4 can be adjusted, thereby adjusting the relative distance between the first mounting member 12 and the second mounting member 1, thereby adapting to the height change of the fuel cell stack 5 located in the accommodating cavity, being more flexible to use and having better versatility.

[0038] In some embodiments, the position-limiting support members 6 correspond to the threaded rods 4 one by one, that is, the number of the position-limiting support members 6 is equal to the number of the threaded rods 4, and each position-limiting support member 6 is connected to a threaded rod 4. In some other embodiments, each position-limiting support member 6 corresponds to a plurality of threaded rods 4, or a plurality of position-limiting support members 6 are correspondingly connected to a threaded rod 4. Preferably, the position-limiting support members 6 correspond to the threaded rods 4 one by one.

[0039] In this embodiment, the position-limiting support member 6 is a strip-shaped structure extending toward the second mounting member 1 , and its cross-sectional shape includes but is not limited to circular, elliptical, rectangular, triangular, and the like.

[0040] In addition to working together with the threaded pull rod 4 to limit the relative position of the first mounting member 12 and the second mounting member 1 to compress the battery stack 5 in the accommodating cavity, the limiting support member 6 can also play a supporting role and prevent the relative displacement or deflection between the single cells of the battery stack 5. Specifically, when the battery stack 5 of the fuel cell stack binding device of this embodiment is laid down (horizontally) for use, part of the limiting support member 6 is located below the battery stack 5, which can support the battery stack 5. Since the extension direction of the limiting support member 6 is the same as the stacking direction of the single cells in the battery stack 5 (both are the arrangement direction of the first mounting member 12 and the second mounting member 1), the limiting support member 6 can limit all the single cells in the battery stack 5 to prevent the relative displacement or deflection between the single cells of the battery stack 5.

[0041] In some embodiments, a plurality of limit support members 6 are symmetrically arranged about a first plane, and a plurality of limit support members 6 located on the same side of the first plane are arranged in sequence along a direction parallel to the first plane, and a plurality of limit support members 6 located on the same side of the first plane are all in contact and cooperate with corresponding sides of the battery stack 5; wherein the first plane is parallel to the extension direction of the limit support members 6 and the threaded pull rod 4.

[0042] Exemplarily, the first mounting member 12 is a rectangular plate, the first plane is perpendicular to a side surface of the first mounting member 12, the first plane is arranged along the length direction of the first mounting member 12 and passes through the center line of the first mounting member 12, and a plurality of limit support members 6 are arranged on two long sides of the first mounting member 12 and are vertically fixed to a side of the first mounting member 12 close to the second mounting member 1. The number of limit support members 6 is an even number greater than 4, the number of limit support members 6 located on the same side of the first plane is greater than 2, preferably, the number of limit support members 6 located on the same side of the first plane is greater than or equal to 3, for example, the number of limit support members 6 on the same side is 3, 4, 5, etc. The limit support members 6 arranged on both sides of the first plane are symmetrical one by one with respect to the first plane. The extension direction of the limit support members 6 is parallel to the first plane, and the plurality of limit support members 6 located on the same side of the first plane are arranged along a direction parallel to the first plane. The plurality of threaded rods 4 correspond to the plurality of limit support members 6 one by one, and the threaded rods 4 are opposite to the corresponding limit support members 6 along the extension direction. When the battery stack 5 is accommodated in the accommodating cavity, one side of all the single cells of the battery stack 5 contacts and cooperates with the multiple limiting supports 6 located on one side of the first plane, and the other side of all the single cells of the battery stack 5 contacts and cooperates with the multiple limiting supports 6 located on the other side of the first plane. Therefore, the limiting supports 6 can provide good support and limiting effects on all the single cells of the battery stack 5.

[0043] To further improve the supporting and limiting effect, optionally, the shapes and sizes of the plurality of limiting supports 6 are equal, and the plurality of limiting supports 6 located on the same side of the first plane are coplanar with a side close to the battery stack 5 or tangent to the same plane.

[0044] Optionally, the limiting support member 6 and the first support member are fixed by, for example, welding, riveting or integral molding, which can ensure the connection strength between the limiting support member 6 and the first support member, thereby ensuring the stability of the overall structure.

[0045] The threaded pull rod 4 of this embodiment includes a threaded rod portion and a head located at one end of the threaded rod. The second mounting member 1 is provided with a through hole. The threaded rod portion is inserted into the through hole and threadedly cooperates with the limiting support member 6. The head is located on the side of the second mounting member 1 away from the first mounting member 12, forming a limit with the second mounting member 1.

[0046] The limiting support 6 and the threaded pull rod 4 are connected by threads. On the one hand, it is convenient to adjust the matching length to adapt to the fuel cell stacks 5 of different heights. On the other hand, the length is fixed after the adjustment is completed and will not change during long-term use, so that the fuel cell stack binding device maintains continuous pressure on the fuel cell stack 5.

[0047] In some embodiments, the fuel cell stack binding device also includes multiple locking members 7, which are disposed at the connection positions of multiple limit supports 6 and multiple threaded tie rods 4. The locking members 7 are respectively connected to the corresponding limit supports 6 and threaded tie rods 4 to lock the relative positions of the limit supports 6 and threaded tie rods 4.

[0048] Optionally, the locking member 7 includes a threaded member, a rivet member or a locking pin, and the locking member 7 is simultaneously connected and matched with the limiting support member 6 and the threaded pull rod 4 .

[0049] For example, the locking member 7 is a screw, a bolt or a locking pin, a first through hole is provided on the limit support member 6, the first through hole is connected to the threaded hole, the threaded pull rod 4 is provided with a second through hole, the locking member 7 is located in the first through hole and is penetrated in the second through hole, and under the action of the locking member 7, the relative position of the limit support member 6 and the threaded pull rod 4 can be locked.

[0050] Furthermore, the threaded rod 4 is provided with a plurality of second through-holes, which are arranged along the extension direction of the threaded rod 4, and the locking member 7 can be selectively penetrated in any of the second through-holes. By providing a plurality of second through-holes, the locking position of the locking member 7 can be adjusted, that is, the matching length of the limit support member 6 and the threaded rod 4 can be adjusted to adapt to battery stacks 5 of different heights.

[0051] In other embodiments, the limiting support member 6 and the threaded pull rod 4 are fixed by welding.

[0052] In some other embodiments, the limiting support member 6 and the threaded pull rod 4 are bonded and fixed.

[0053] It should be noted that the relative fixation of the limit support member 6 and the threaded tie rod 4 by the locking member 7 or welding or bonding is performed after the stacking is completed, and the continuous stacking force is ensured by locking or fixing.

[0054] In some embodiments of the present invention, the fuel cell stack binding device further includes a floating member 10 and at least one elastic member 11. The floating member 10 is movably disposed in the accommodating cavity and abuts against one end of the stack 5 facing the first mounting member 12. The elastic member 11 includes one or any combination of two or more of a butterfly spring, a coil spring, and a leaf spring, and the elastic member 11 is elastically supported between the first mounting member 12 and the floating member 10.

[0055] When the relative positions of the first mounting member 12 and the second mounting member 1 are adjusted and the battery stack 5 is compressed, the floating member 10 and the second mounting member 1 squeeze the two ends of the battery stack 5 respectively, and the floating member 10 can move during the compression of the battery stack 5 to adapt to the height change of the battery stack 5, ensuring that the battery stack 5 will not be damaged during the press-fitting process due to the limitation of the fixed height. The elastic member 11 can be deformed during the compression of the battery stack 5, providing continuous elastic pressure to ensure that the battery stack 5 always maintains a stable pressing force after press-fitting. During the long-term use of the battery stack 5, the battery stack 5 may undergo slight deformation due to material aging, temperature changes and other reasons. In addition, during the operation of heavy trucks, the actual road conditions are relatively complex. Due to the bumpy road surface, the vibration shock to the battery stack 5 is relatively large and lasts for a long time. Each single cell fixed by pressurization is prone to slight dislocation or even overall collapse. The elastic member 11 can compensate for these deformations to ensure that the pressing force of the battery stack 5 will not weaken over time. The use of the elastic member 11 can improve the mechanical reliability of the battery stack 5 and reduce the performance degradation and failure risks caused by insufficient pressing force.

[0056] In some embodiments of the present invention, the surface of at least one of the first mounting member 12, the second mounting member 1, the limiting support member 6 and the threaded pull rod 4 is provided with an insulating material layer. Preferably, the surfaces of the first mounting member 12, the second mounting member 1, the limiting support member 6 and the threaded pull rod 4 are all coated with an insulating material layer and are all wrapped by the insulating material layer.

[0057] Insulating materials can prevent current short circuits and electrochemical corrosion, and can also provide certain assistance in reducing electromagnetic interference, improving mechanical strength, improving thermal management and corrosion protection, etc., significantly improving the performance and reliability of the fuel cell stack 5 and ensuring its stable operation in various application scenarios.

[0058] Combination Figure 2 and Figure 4In some embodiments of the present invention, the battery stack 5 includes a plurality of stacked single cells, and the stacking direction of the plurality of single cells is parallel to the extending direction of the limit support 6 and the threaded pull rod 4. Stacking means that the plurality of single cells are stacked in the same direction, and the adjacent single cells are parallel and attached.

[0059] Optionally, in a stacking direction perpendicular to the single cell, the relative offset between any two of the multiple single cells is less than or equal to 0.5 mm. Preferably, the relative offset between any two of the multiple single cells is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.

[0060] In the manufacturing process of the fuel cell stack 5, the precise alignment and positioning of the single cells are crucial. The relative offset between the single cells will affect the performance, reliability and life of the stack 5. If the offset is too large, it will cause problems such as poor contact inside the stack 5, uneven gas distribution, and poor cooling effect; if the offset is too small, it may cause assembly difficulties and increased costs. Therefore, reasonable control of the relative offset between the single cells is one of the key factors to improve the performance of the stack 5.

[0061] In the present embodiment, the relative offset between any two single cells among the multiple single cells is within the above range, which can significantly reduce the poor contact between the single cells. Poor contact will lead to increased local resistance, which will cause power loss and local overheating, affecting the performance and life of the battery stack 5. A smaller offset helps to evenly distribute the gas on the MEA, ensure that hydrogen and oxygen can fully react, and improve the electrochemical efficiency of the battery stack 5. The relative offset between the single cells is small, which can ensure the uniform flow of the coolant in the cooling channel, effectively take away the heat inside the battery stack 5, and keep the operating temperature of the battery stack 5 within a reasonable range. In addition, a smaller offset can improve the mechanical stability of the battery stack 5 and reduce structural damage caused by vibration and impact.

[0062] Optionally, the stacking force of multiple single cells along the stacking direction of the single cells (the extension direction of the limiting support 6 and the threaded pull rod 4) is greater than 0.6 MPa and less than 1.5 MPa. Preferably, the stacking force of multiple single cells along the stacking direction of the single cells is greater than 0.9 MPa and less than 1.2 MPa.

[0063] During the manufacturing and operation of the fuel cell stack 5, the stacking force is a key parameter that directly affects the performance, reliability and life of the stack 5. The stacking force refers to the pressure applied in the stacking direction of the single cells, which is used to ensure good contact between the single cells, reduce contact resistance, and improve the efficiency of the electrochemical reaction. However, excessive stacking force may cause material damage, while too small stacking force may cause poor contact. Therefore, reasonable control of the stacking force is an important means to optimize the performance of the stack 5.

[0064] In this embodiment, controlling the stacking force within the above range has the following advantages: it can significantly reduce the contact resistance between the single cells and improve the electrochemical efficiency of the stack 5. The reduction in contact resistance means a reduction in power loss, thereby improving the overall performance. It also helps to evenly distribute the gas on the MEA, ensuring that hydrogen and oxygen can fully react and improve the output power of the stack 5. It reduces structural damage caused by vibration and impact, extends the service life of the stack 5, and prevents damage to the single cell materials due to excessive pressure, avoiding performance degradation and safety hazards.

[0065] It is worth noting that the offset and the stacking force are realized by the structure of the fuel cell stack binding device. For example, the second mounting member 1 and the floating member 10 act on the stack 5, and the pressure applied to the stack 5 satisfies the pressure greater than 0.6 MPa and less than 1.5 MPa, so that the stacking force of multiple single cells is greater than 0.6 MPa and less than 1.5 MPa. For another example, the limiting support member 6 provides a limiting support function on both sides of the stack 5 to ensure that the relative position of the single cells in the vertical direction of the stacking direction remains consistent. The pressing effect of the second mounting member 1 and the floating member 10 further ensures good contact between the single cells and reduces the relative offset. Under the limiting support effect of the limiting support member 6 and the pressing effect of the second mounting member 1 and the floating member 10, it is ensured that the relative offset between any two single cells in the multiple single cells is less than or equal to 0.5 mm.

[0066] Optionally, the battery stack 5 further includes an upper current collecting plate 3, an upper insulating plate 2, a lower current collecting plate 8 and a lower insulating plate 9. The upper current collecting plate 3 and the upper insulating plate 2 are located on a side of the plurality of stacked single cells close to the second mounting member 1. The lower current collecting plate 8 and the lower insulating plate 9 are located on a side of the plurality of stacked single cells close to the first mounting member 12, specifically between the plurality of stacked single cells and the floating member 10. The upper current collecting plate 3 is usually made of a material with good electrical conductivity, which can significantly improve the electrical conductivity of the battery stack 5 and reduce electrical energy loss.

[0067] Among them, the upper current collecting plate 3 can ensure that the current is evenly distributed throughout the battery stack 5, avoiding local overheating and performance degradation. The upper insulating plate 2 is used to isolate the upper current collecting plate 3 and the second mounting member 1 to prevent current leakage and ensure the safe operation of the battery stack 5. The lower current collecting plate 8 is also used to collect and conduct the current generated by the single cell to ensure that the current is evenly distributed and reduce resistance loss. The lower insulating plate 9 is used to isolate the lower current collecting plate 8 and components such as the floating member 10 and the first mounting member 12 to prevent current leakage and ensure the safe operation of the battery stack 5.

[0068] Combination Figure 5 This embodiment also provides a fuel cell stack binding method, which is applied to the above-mentioned fuel cell stack binding device, and the method includes:

[0069] S100 , stacking all the single cells of the battery stack 5 between the first mounting member 12 and the second mounting member 1 .

[0070] Specifically, ensure that all single cells have been rigorously inspected and tested and meet performance and quality requirements. Clean the surface of all single cells to ensure that there is no dust, oil or other impurities. Check the appearance of the single cells to ensure that there is no obvious damage or defects. Stack the single cells one by one in a predetermined order to ensure that each single cell is well aligned and in contact. Use special clamps or positioning tools to ensure that the single cells do not shift during the stacking process. Place the first mounting member 12 on the workbench as the base of the battery stack 5. Place the stacked single cells on the first mounting member 12. Place the second mounting member 1 above the single cell to ensure that the second mounting member 1 is parallel and aligned with the first mounting member 12.

[0071] Optionally, when the fuel cell stack binding device further includes an elastic member 11 and a floating member 10, stacking all the single cells of the fuel cell stack 5 between the first mounting member 12 and the second mounting member 1 includes:

[0072] All the single cells of the battery stack 5 are stacked between the first mounting member 12 and the second mounting member 1 , and all the single cells of the battery stack 5 are stacked on the upper side of the floating member 10 .

[0073] S200 , applying a preset pressure to the first mounting member 12 and the second mounting member 1 to bring them closer to each other.

[0074] A pressing device (such as a hydraulic press or a pneumatic presser) is installed on the upper side of the second mounting member 1, and the second mounting member 1 is pressed down by the pressing device to apply a preset pressure to the first mounting member 12 and the second mounting member 1 to move them closer to each other.

[0075] The preset pressure should meet the following requirements: the pile pressing force is greater than 0.6 MPa and less than 1.5 MPa. Furthermore, the pile pressing force is greater than 0.9 MPa and less than 1.2 MPa.

[0076] Optionally, a pressure sensor is used to monitor the pile pressing force in real time to ensure that the pile pressing force is always within a specified range, and the setting of the compacting device is adjusted according to the monitoring result to ensure that the pile pressing force is uniform and stable.

[0077] S300, threading the threaded pull rod 4 and the limiting support member 6 together.

[0078] Use a torque wrench or other tightening tools to tighten the threaded tie rod 4 according to the specified torque value to ensure that the compressing force is uniform and stable. Further, check the connection between the threaded tie rod 4 and the limit support 6 to ensure that there is no looseness or damage.

[0079] Through the above three steps, the fuel cell stack 5 can be effectively assembled to ensure that the stacking, pressing force and relative offset of the single cells are within a reasonable range. These steps not only improve the performance and reliability of the stack 5, but also simplify the assembly process and reduce production costs.

[0080] The method for fastening the fuel cell stack 5 in some embodiments further includes:

[0081] The material property parameters of the single cell are determined based on the geometric parameters, morphological parameters, fractal parameters and conductivity of the single cell, and the theoretical minimum stacking force is determined based on the material property parameters of the single cell, the contact resistance and contact area between each single cell, and the number of single cells in the stack 5.

[0082] Specifically, in order to ensure consistent and reliable performance during the production and processing of the battery stack 5, the stacking force must be large enough to prevent leakage of the working fluid of each single battery, while minimizing the contact resistance. To achieve the above requirements, the following relationship must be satisfied:

[0083]

[0084]

[0085]

[0086] Where F is the actual compressive force, is the theoretical minimum compaction force, It is a function of the contact resistance R between each single cell, the contact area A, the number of single cells in the whole stack n, and the material property parameter X of the single cell;

[0087] Among them, X is calculated through the geometric parameters K of the single cell (such as length, width, thickness, surface area, edge fillet radius, etc.), morphological parameters G (such as surface roughness, surface waviness, surface texture, surface porosity, surface hardness, surface friction coefficient, etc.), fractal parameters D (such as fractal dimension, fractal density, fractal roughness, fractal porosity, etc.) and conductivity k.

[0088] The theoretical maximum stacking force is determined based on the battery working fluid transmission characteristic parameters and the battery structure strength requirement parameters.

[0089] Specifically, if the compression force is too large, the layers of the single cell will be too dense, and the water vapor transmission characteristics will be lost, resulting in a serious decline in performance. Therefore, the compression force cannot exceed the theoretical maximum compression force. , the following relationship must be satisfied:

[0090]

[0091]

[0092] in, is the theoretical maximum stacking force, S is the battery working fluid transmission characteristic parameter (such as gas diffusion coefficient, permeability, porosity, flow resistance factor, mass transfer coefficient, thermal conductivity, etc.), and J is the battery structural strength requirement parameter (such as maximum compressive stress, maximum shear stress, fatigue strength, yield strength, fracture toughness, elastic modulus, thermal expansion coefficient, etc.). The battery working fluid transmission characteristic parameters and the battery structural strength requirement parameters jointly determine the theoretical upper limit of the stacking force.

[0093] The above single cell material property parameter X, theoretical minimum stacking force and theoretical maximum compaction force The calculation formula can be obtained through theoretical analysis, experimental verification and engineering experience. Since the specific formula and its acquisition method do not involve improvements other than this application, they will not be introduced in detail.

[0094] The preset pressure is greater than or equal to the theoretical minimum compression force, and less than or equal to the maximum compression force. That is, in the actual loading process, the compression force must be controlled to meet the following relationship:

[0095]

[0096] In order to ensure performance requirements, the compression force is generally controlled at 0.6 MPa-1.5 MPa, that is, , preferably, the compressing force is 0.9 MPa-1.2 MPa.

[0097] In this embodiment, through the above steps, the theoretical minimum compression force and the theoretical maximum compression force of the fuel cell stack 5 can be accurately determined, and the compression force can be controlled within a reasonable range during the actual stacking process. These steps and technical effects ensure the performance, reliability and life of the stack 5. Specifically, by comprehensively considering geometric parameters, morphological parameters, fractal parameters and conductivity, the material properties of the single cell are accurately described. The theoretical minimum compression force is determined to ensure that the compression force is large enough to prevent leakage of the working fluid while minimizing the contact resistance. The theoretical maximum compression force is determined to ensure that the compression force is not too large, maintain the water vapor transmission characteristics, and prevent structural damage. In the actual stacking process, the compression force is controlled between the theoretical minimum compression force and the theoretical maximum compression force to ensure consistent and reliable performance.

[0098] The method for fastening the fuel cell stack 5 in some embodiments further includes:

[0099] The maximum offset between the single cells is determined based on the number of single cells in the battery stack 5 and the performance requirement parameters of the battery stack 5 .

[0100] Specifically, the positioning of a long stack is more difficult than that of a short stack. In order to prevent the stack 5 from being dislocated or deflected due to strong pressure during the stacking process, thereby affecting the performance output, the maximum offset must satisfy the following relationship:

[0101]

[0102]

[0103] Where n is the number of single cells. is the relative offset distance between any two single cells in the entire battery stack, and P is the performance requirement parameter of the battery stack (for example, electrical performance parameters such as voltage, current, power, efficiency, and / or thermal management parameters, mechanical performance parameters, etc.), that is, the maximum offset between any single cells in the battery stack is related to the performance requirements of the battery stack.

[0104] To ensure performance requirements, the relative offset of any two single cells is generally controlled within 0.5 mm. The preferred offset range is between 0.2 mm and 0.4 mm.

[0105] By determining the maximum offset between the single cells based on the number of single cells in the battery stack 5 and the performance requirement parameters of the battery stack 5 , it is possible to effectively prevent the long stack from being misaligned or skewed during the stacking process, thereby ensuring the performance output of the battery stack 5 .

[0106] The above method and formula provide important guidance for the design and manufacture of the fuel cell stack 5, ensuring that the stack 5 exhibits the best performance and highest safety in practical applications.

[0107] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A fuel cell stack binding device, characterized in that: include: a first mounting member; a second mounting member, arranged opposite to the first mounting member; A plurality of position-limiting support members, fixedly connected to the first mounting member, arranged along the circumference of the first mounting member and extending toward the second mounting member, and a threaded hole extending along the extension direction of the position-limiting support member is provided at one end of the position-limiting support member facing the second mounting member; A plurality of threaded rods are rotatably connected with the threaded rods and extend toward the first mounting member, the first mounting member is provided with external threads, the plurality of threaded rods correspond to the plurality of position-limiting supports respectively, and the threaded rods are connected to the corresponding position-limiting supports through the threaded holes and the external threads; Wherein, a receiving cavity for receiving the battery stack is formed between the first mounting member, the second mounting member, the limiting support member and the threaded pull rod.

2. The fuel cell stack binding device according to claim 1, characterized in that: The plurality of position-limiting support members are symmetrically arranged about the first plane, the plurality of position-limiting support members located on the same side of the first plane are arranged in sequence along a direction parallel to the first plane, and the plurality of position-limiting support members located on the same side of the first plane are in contact with and cooperate with corresponding sides of the battery stack; Wherein, the first plane is parallel to the extension direction of the limiting support member and the threaded pull rod.

3. The fuel cell stack binding device according to claim 1 or 2, characterized in that: The fuel cell stack binding device further comprises: a plurality of locking members, which are disposed at connection positions of the plurality of limit support members and the plurality of threaded tie rods, and the locking members are respectively connected to the corresponding limit support members and the threaded tie rods to lock the relative positions of the limit support members and the threaded tie rods; Alternatively, the position-limiting support member and the threaded pull rod are fixed by welding; Alternatively, the position-limiting support member and the threaded pull rod are bonded and fixed.

4. The fuel cell stack binding device according to claim 3, characterized in that: The locking member comprises a threaded member, a rivet member or a locking pin, and the locking member is simultaneously connected and matched with the limiting support member and the threaded pull rod.

5. The fuel cell stack binding device according to claim 4, characterized in that: The position-limiting support member is provided with a first through hole, and the threaded rod is provided with a plurality of second through holes, and the plurality of second through holes are arranged along the extension direction of the threaded rod; The locking element is located in the first through hole, and can be selectively arranged in any one of the second through holes.

6. The fuel cell stack binding device according to claim 1 or 2, characterized in that: Also includes: A floating member, movably disposed in the accommodating cavity, abutting against an end of the battery stack facing the first mounting member; At least one elastic member, the elastic member includes one or any combination of two or more of a butterfly spring, a spiral spring, and a leaf spring, and the elastic member is elastically supported between the first mounting member and the floating member.

7. The fuel cell stack binding device according to claim 6, characterized in that: An insulating material layer is provided on the surface of at least one of the first mounting member, the second mounting member, the position-limiting support member, the threaded pull rod and the floating member.

8. The fuel cell stack binding device according to claim 1 or 2, characterized in that: The battery stack comprises a plurality of stacked single cells, wherein the stacking direction of the plurality of single cells is parallel to the extending direction of the limiting support member and the threaded pull rod; In a stacking direction perpendicular to the single cells, the relative offset between any two of the plurality of single cells is less than or equal to 0.5 mm; and or, the stacking force of the plurality of single cells along the stacking direction of the single cells is greater than 0.6 MPa and less than 1.5 MPa.

9. A fuel cell stack binding method, characterized in that: Applied to the fuel cell stack binding device according to any one of claims 1 to 8, the method comprising: Stacking all the single cells of the battery stack between the first mounting member and the second mounting member; Applying a preset pressure to the first mounting member and the second mounting member to move them closer to each other; Thread the threaded tie rod and the limit support piece.

10. The fuel cell stack binding method according to claim 9, characterized in that: Also includes: Determine the material property parameters of the single cell based on the geometric parameters, morphological parameters, fractal parameters and conductivity of the single cell, and determine the theoretical minimum stacking force based on the material property parameters of the single cell, the contact resistance and contact area between each single cell, and the number of the single cells in the battery stack; Determine the theoretical maximum stacking force based on the battery working fluid transmission characteristic parameters and battery structural strength requirement parameters; The preset pressure is greater than or equal to the theoretical minimum stack pressing force, and less than or equal to the maximum stack pressing force.

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