Fuel cell stack, fuel cell system and vehicle

Abstract

The present invention discloses a fuel cell stack, a fuel cell system, and a vehicle, which optimize the core performance of the fuel cell stack. The fuel cell stack includes an end plate assembly and a fastening assembly. The end plate assembly includes at least two end plates distributed at both ends of the fuel cell stack; the width of the middle portion of the end plate is smaller than the width of the two end portions of the end plate; the fastening assembly includes at least three fastening units, both ends of which are connected to the end plate assembly and are distributed at the middle portion and the end portions of the end plate; the thickness of the fastening unit connected to the middle portion is greater than the thickness of the fastening unit connected to the end portions. By designing the end plate shape of the end plate assembly to match the shape of the special-shaped bipolar plate, different fastening forces are provided at the middle portion and end plates of the stack through different fastening schemes, effectively improving the power-to-volume ratio of the fuel cell stack and maximally balancing the stress conditions in the reaction zone.

Description

Technical Field

[0001] The present invention relates to the field of fuel cell technology, and in particular to a fuel cell stack, a fuel cell system and a vehicle. Background Art

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts the chemical energy of fuel into electrical energy. It has the advantages of low operating temperature, fast startup, high specific power, simple structure and easy operation. Therefore, fuel cells are widely used in the automotive industry, energy generation, shipbuilding industry, aerospace, household power supply and other industries.

[0003] However, the fuel cell stack in the prior art has technical problems such as reduced power-to-volume ratio and a certain deviation between the performance of the stack core and the designed performance, which limits the development of fuel cells. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to overcome the shortcomings of the existing technology and provide a fuel cell stack, a fuel cell system and a vehicle, which ensure the core performance of the fuel cell stack while effectively improving the power-to-volume ratio of the fuel cell stack.

[0005] The technical solution for achieving the technical purpose of the present invention is a fuel cell stack comprising:

[0006] An end plate assembly comprising at least two end plates, the at least two end plates being distributed at both ends of the fuel cell stack; the width of the middle portion of the end plate being smaller than the width of the two end portions of the end plate;

[0007] The fastening assembly includes at least three fastening units, both ends of which are connected to the end plate assembly and are distributed at the middle and end parts of the end plate; the thickness of the fastening unit connected to the middle part is greater than the thickness of the fastening unit connected to the end part.

[0008] In certain embodiments, the fastening assembly includes at least six fastening units, and the at least six fastening units are distributed on at least two opposite sides of the fuel cell stack; the at least two end plates are respectively an intake end plate and a blind end end plate assembly, and the two ends of the fastening unit are respectively connected to the intake end plate and the blind end end plate assembly.

[0009] In some embodiments, the fastening unit includes a fastener; or the fastening unit includes a fastener and an insulating support member, and the insulating support member is disposed between the core of the fuel cell stack and the fastener;

[0010] The fastener is a pull rod and / or a steel belt, and both ends of the fastener are respectively connected to the air intake end plate and the blind end plate assembly.

[0011] In some embodiments, the fasteners connected to the middle portion are pull rods, and the number of the pull rods is at least 4; the fasteners connected to the end portions are steel strips.

[0012] In some embodiments, the outer side surface of the tie rod and the outer side surface of the steel belt located on the same side of the end plate assembly are coplanar.

[0013] In some embodiments, both ends of the end plate are connected to the fastening unit, and at least one of the fastening units connected to the end includes a fastener and an insulating support member, and the insulating support member has a bent portion extending to the adjacent short side or long side of the core of the fuel cell stack, which is used to limit the core.

[0014] In some embodiments, the fastening unit is provided on both the long side and the short side of the end portion;

[0015] The fastening unit connected to the long side of the end portion includes a fastener and an insulating support; the fastening unit connected to the short side of the end portion includes a fastener.

[0016] In some embodiments, a limiting structure is provided on the fastener and / or the insulating support, and the fastener and the insulating support are positioned by the limiting structure; and / or the insulating support has a recessed groove, and the fastener is interference fit with the recessed groove.

[0017] In some embodiments, the fastening assembly further includes a connector for connecting the fastening unit and the end plate assembly; the fastening unit further includes fastening joints respectively connected to both ends of each fastening unit, and the connector connects the fastening joint and the end plate assembly.

[0018] Based on the same inventive concept, the present invention also provides a fuel cell system including the above-mentioned fuel cell stack.

[0019] Based on the same inventive concept, the present invention also provides a vehicle comprising the above-mentioned fuel cell system.

[0020] As can be seen from the above technical solution, the fuel cell stack provided by the present invention includes an end plate assembly and a fastening assembly, wherein the end plate assembly includes at least two end plates, and the at least two end plates are distributed at both ends of the fuel cell stack; the width of the middle portion of the end plate is smaller than the width of the two ends of the end plate, and the end plate of the end plate assembly matches the shape of the special-shaped bipolar plate. Compared with the cubic end plate in the prior art, the end plate in the present invention avoids volume waste and can effectively improve the power-to-volume ratio of the stack. The fastening assembly includes at least three fastening units, and both ends of the at least three fastening units are connected to the end plate assembly and are distributed at the middle portion and the end portions of the end plate; the applicant found that due to the external dimensions of the special-shaped bipolar plate and the design of the gas-liquid flow channel, the cubic end plate plus a single-form fastening structure in the prior art cannot ensure that the packaging force at each position of the reaction zone is the same while reducing the volume-to-power ratio. In the fuel cell stack provided by the present invention, the thickness of the fastening unit connected to the middle part is greater than the thickness of the fastening unit connected to the end part. Different fastening schemes are used to provide different sizes of fastening forces in the middle part and end plate of the stack to adapt to deformation and stress at different positions, thereby balancing the stress conditions in the reaction zone as much as possible and effectively ensuring the optimal performance of the core.

[0021] The fuel cell and vehicle provided by the present invention, having the above-described fuel cell stack, on the one hand, reduce the space occupied by the end plate in the long-side direction and effectively increase the power volume of the stack by designing the end plate assembly to have a shape and size that matches the shape of the special-shaped bipolar plate. On the other hand, by utilizing the recessed space in the middle of the end plate assembly, the thickness of the fastening unit connected to the middle is designed to be greater than the thickness of the fastening unit connected to the end. The thicker and stronger fastening unit provides the main fastening force, while the fastening units at the end provide auxiliary fastening force and are used to seal the core. Different fastening forces are provided by different fastening schemes according to the force requirements of the core, thereby maximally balancing the force conditions in the reaction zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of a fuel cell stack provided in Example 1 of the present invention;

[0023] Figure 2 for Figure 1 A schematic diagram of an intake end plate of an end plate assembly of a fuel cell stack;

[0024] Figure 3 for Figure 1 A front view of a fastening joint of a fastening assembly of a fuel cell stack;

[0025] Figure 4 for Figure 3 Rear view of the fastening joint in FIG;

[0026] Figure 5 for Figure 3 A side view of a fastening joint in FIG.

[0027] Figure 6 for Figure 3 Rear view of the fastening joint in FIG;

[0028] Figure 7 for Figure 1 A structural front view of a fastening assembly of a fuel cell stack;

[0029] Figure 8 for Figure 7 a side view of a fastening assembly;

[0030] Figure 9 for Figure 7 A front view of a tie rod and a fastening joint in a fastening assembly;

[0031] Figure 10 for Figure 7 A rear view of a tie rod and a fastening joint in a fastening assembly;

[0032] Figure 11 for Figure 7 A top view of the tie rod and the fastening joint in the fastening assembly;

[0033] Figure 12 for Figure 7 A side view of an insulating rod in a fastening assembly;

[0034] Figure 13 for Figure 1 A front view of another structure of a fastening assembly of a fuel cell stack;

[0035] Figure 14 for Figure 13 A rear view of the steel belt and the fastening joint in the fastening assembly;

[0036] Figure 15 for Figure 13 A top view of the steel belt and the fastening joint in the fastening assembly;

[0037] Figure 16 for Figure 13 A side view of the steel belt and the fastening joint in the fastening assembly;

[0038] Figure 17 for Figure 13 Schematic cross-section of the assembly of the steel strip and the insulating support.

[0039] Explanation of the accompanying reference numerals: 100 - fuel cell stack, 101 - air inlet end plate, 102 - blind end end plate assembly, 103 - air inlet end collecting plate, 104 - blind end collecting plate, 105 - core; 110 - fastening unit, 111 - fastener, 112 - pull rod, 113 - steel belt, 114 - fastening joint, 115 - insulating support, 116 - bending part, 117 - sink, 120 - connecting part. DETAILED DESCRIPTION

[0040] The applicant discovered that the existing fuel cell stack end plate assemblies all use the largest rectangle that can accommodate the bipolar plate's outer shape as their outer contour. This design, whether applied to regular rectangular or irregular bipolar plates, inevitably results in volume loss when applied to these irregularly shaped plates, leading to a reduction in the stack's power-to-volume ratio. Furthermore, the stack typically employs only one fastening scheme, employing tie rods, steel strips, or screws. The special features of irregularly shaped bipolar plates are not considered in the fastening design, resulting in performance deviations in the fuel cell stack, preventing optimal performance.

[0041] Through research, it was found that due to the external dimensions of the special-shaped bipolar plates and the design of the gas-liquid flow channels, the cubic end plates plus a single form of fastening structure in the prior art cannot ensure that the packaging force at each position in the reaction zone is the same. In order to solve the above technical problems, the present invention provides a fuel cell stack, a fuel cell system and a vehicle. The inventive concept of this application is to design the shape of the end plate to match the shape of the special-shaped bipolar plate, and at the same time design the fastening assembly to a structure that matches the shape of the end plate. Through the combination of the two, the power-to-volume ratio of the fuel cell stack is effectively improved while meeting the packaging force required at each position in the reaction zone, balancing the stress conditions in the reaction zone as much as possible, and ensuring the core performance of the fuel cell stack.

[0042] The present invention is described in detail below through three specific embodiments:

[0043] Example 1

[0044] like Figures 1-17As shown, this embodiment provides a fuel cell stack 100, including an end plate assembly and a fastening assembly. The end plate assembly includes at least two end plates, with the at least two end plates distributed at both ends of the fuel cell stack 100. The width of the middle portion of the end plate is smaller than the width of the two ends of the end plate. The end plates of the end plate assembly match the shape of the special-shaped bipolar plates. Compared with the cubic end plates in the prior art, the end plates of the present invention effectively avoid the waste of space and volume on the side of the fuel cell stack 100, which can effectively improve the power-to-volume ratio of the stack. The fastening assembly includes at least three fastening units 106, each of which is connected to the end plate assembly at both ends and is distributed in the middle and end portions of the end plate. The thickness of the fastening unit 106 connected to the middle portion is greater than the thickness of the fastening unit 106 connected to the end portion. Through different fastening schemes, different fastening forces are provided in the middle and end plates of the stack to adapt to deformation and stress at different locations, thereby balancing the stress conditions in the reaction zone as much as possible and effectively ensuring the optimal performance of the core 105.

[0045] It should be noted that the present application does not impose any specific restrictions on the selection of each fastening unit 106, and the design and selection can be made according to actual needs, that is, it can be any of the fastening schemes of screws, pull rods 112 and wound steel belts 113 in the prior art. However, compared with the pull rods 112 and the wound steel belts 113, since the volume occupied by the screws is larger, in order to take into account the volume control of the fuel cell, it is preferred to adopt the fastening scheme of pull rods 112 and / or wound steel belts 113. The present invention does not impose any specific restrictions on the number and setting method of the fastening units 106, and can be adaptively adjusted and selected according to different needs. The fastening of the fuel cell stack 100 is achieved by at least three fastening units 106. The smallest implementation method is to use three winding structures that are U-shaped and wound around the long side of the fuel cell stack 100. At this time, the two ends of the winding structure are connected to the same end plate.

[0046] To achieve height control of the fuel cell stack 100 and provide sufficient packaging and tightening force to ensure the performance of the fuel cell stack 100, in this embodiment, the tightening assembly may include at least six tightening units 106. The at least six tightening units 106 are distributed on at least two opposing sides of the fuel cell stack 100 to provide stable tightening force. The at least two end plates are an intake end plate 101 and a blind end plate assembly 102. The ends of the tightening units 106 are respectively connected to the intake end plate 101 and the blind end plate assembly 102 located on the outermost sides of the stack core 105.

[0047] This application does not limit the specific structure of a single fastening unit 106, and other structures not mentioned can refer to the prior art. As an embodiment, the fastening unit 106 includes a fastener 111; or the fastening unit 106 includes a fastener 111 and an insulating support 115, and the insulating support 115 is arranged between the core 105 of the fuel cell stack 100 and the fastener 111. As mentioned above, in order to control the volume of the fuel cell stack 100, as a preferred embodiment, all the fasteners 111 in more than two fastening units 106 are tie rods 112 and / or steel strips 113, and the two ends of the fasteners 111 are respectively connected to the intake end plate 101 and the blind end plate assembly 102, that is, the two ends of the tie rods 112 and / or steel strips 113 are both connected to the end plate assembly, that is, in this embodiment, the structure of multiple fastening assemblies can include at least one of the above, that is, the fuel cell stack 100 can adopt a fastening scheme combining one or more fastening units 106.

[0048] When the fastening unit 106 only includes the fastener 111, the need for additional insulation protection can be determined based on design requirements. For example, when the fastener 111 is a tie rod 112, if creepage clearance or insulation requirements are met, no additional insulation protection is required. If the tie rod 112 fails to meet the insulation requirements or to prevent the steel strip 113 from collapsing, posing a safety hazard, an insulation layer can be provided on the tie rod 112 / steel strip 113 to provide insulation protection. To prevent electrical safety issues caused by the steel strip 113 collapsing due to insufficient or attenuated fastening force, preferably, the steel strip 113 in this embodiment is provided with an insulation layer.

[0049] Since the middle part of the end plate corresponds to the middle part of the fuel cell stack 100, the middle part is the key fastening object. In order to ensure the fastening package, in this embodiment, the fastener 111 connected to the middle part is a pull rod 112, the number of the pull rods 112 is at least 4, and at least 4 pull rods 112 are distributed on the two long sides; the fastener 111 connected to the end is a steel strip 113, which provides the main fastening force through at least 4 pull rods 112 with high rigidity and poor deformation resistance; the steel strip 113 is relatively thin and has poor rigidity, and assists in providing fastening force at the end, mainly sealing the core 105, and provides different sizes of fastening forces at different positions of the end plate assembly through fasteners 111 with different structures and different thicknesses, meeting the actual fastening force required at different positions to achieve uniform compression deformation, and can balance the stress conditions in the reaction zone as much as possible.

[0050] The present invention does not specifically limit the setting position of the steel belt 113 set at the end. It can be set on the long side and / or short side. If the pull rod 112 located in the middle of the long side can be sufficient to meet the main tightening force requirements, the steel belt 113 can be set on the short side. If the tightening force on the long side cannot meet the requirements, the steel belt 113 can be set on the upper side of the middle pull rod 112. In addition, an auxiliary tightening steel belt 113 can be set on the short side. The above can be adjusted according to actual needs.

[0051] In order to further control the volume-to-power ratio of the fuel cell stack 100, preferably, the outer side surfaces of the tie rods 112 on the same side of the end plate assembly are coplanar, or the outer side surfaces of the tie rods 112 and the steel belt 113 on the same side of the end plate assembly are coplanar.

[0052] In order to prevent the fuel cell stack from collapsing and to limit its position, in this embodiment, both ends of the end plate are connected to a fastening unit 106, and at least one fastening unit 106 connected to the end includes a fastener 111 and an insulating support 115. The insulating support 115 has a bending portion 116 extending to the adjacent short side or long side of the core 105 of the fuel cell stack 100, which is used to limit the core 105.

[0053] To ensure effective fastening, in this embodiment, fastening elements 106 are provided on both the long and short sides of the end plates. Specifically, four locations along the middle of the long sides are tie rods 112, and six locations along the ends of the long sides and the middle of the short sides are steel strips 113. The end plates are only slightly larger than the outer contours of the bipolar plates, which places the metal fastening elements 106 close to the core 105, potentially causing leakage. The tie rods 112 and steel strips 113 are too close to the core 105. To ensure insulation and prevent the core 105 from collapsing, the fastening elements 106 connected to the long sides of the end plates include fasteners 111 and insulating supports 115. The insulating supports 115 are designed to be sandwiched between the fasteners 111 and the core 105, ensuring complete insulation. The insulating rods are fully adhered to the core 105. The steel strips 113 at the ends of the long sides are designed to prevent collapse. The insulating rods are wrapped around the short sides of the bipolar plates and extend to the locations near the steel strips 113 on the short sides. The fastening unit 106 connected to the short side of the end portion includes a fastener 111. In order to simplify the structure and control the weight, the steel strip 113 in the short side direction is only wrapped with an insulating layer on the outside.

[0054] In order to limit the relative movement of the fastener 111 and the insulating support 115, in this embodiment, a limiting structure is provided on the fastener 111 and / or the insulating support 115, and the fastener 111 and the insulating support rod are positioned by the limiting structure; and / or, the insulating support 115 has a recessed groove 117, and the fastener 111 is interference fit with the recessed groove 117.

[0055] In addition, this embodiment does not specifically limit the insulation method of the core 105 of the fuel cell stack 100 on the blind end side and the air intake end side. For example, in some embodiments, an insulating plate can be added before the collecting plate and the end plate, the same as the prior art. In some embodiments, it is also possible to consider integrating the structure and function of the insulating plate on the end plate assembly, such as setting the end plate assembly to an integrated aluminum-plastic structure.

[0056] It should be noted that this embodiment does not limit the shape and structure of the inlet-end collector plate 103 and the blind-end collector plate 104 of the fuel cell stack 100. Reference can be made to either the prior art or the structural shape of the end plate assembly of this embodiment. That is, when the single cell (bipolar plate and membrane electrode) is I-shaped or dumbbell-shaped, in some embodiments, the inlet-end collector plate 103 and the blind-end collector plate 104 can be configured as rectangular plates with a cross-sectional length and width that are smaller than the length and width of the adjacent end plate, as long as the connection and installation of the end plate assembly and the fastening assembly are met. In some embodiments, in order to cooperate with the special-shaped structure of the end plate to achieve a better balance of the fastening force at various locations, and at the same time, since the protruding height of the insulating plate collecting ear is the same as the collecting plate collecting ear, in order to achieve insulation between the collecting plate and the core 105, a certain height is required to reserve installation space for the fastening assembly. Preferably, the width of the middle part of the inlet end collecting plate 103 and the blind end collecting plate 104 is smaller than the width of the two ends of the end plate, that is, it matches the shape of the single cell. In a further preferred embodiment, the size of the collecting plate is also the same as that of the single cell.

[0057] In order to fix the fastening assembly on the end plate assembly, in this embodiment, the fastening assembly also includes a connector 120 for connecting the fastening unit 106 and the end plate assembly. The structural design of the connector 120 and the corresponding structures of the end plate assembly, the fastening assembly and the connector 120 can all refer to the existing technology and will not be elaborated in this embodiment.

[0058] In order to improve the adaptability of assembly and ensure the feasibility of the combined fastening scheme of the pull rod 112 and the steel belt 113, in the fuel cell stack 100 provided in this embodiment, the fastening unit 106 also includes a fastening joint 114 respectively connected to the two ends of each fastening unit 106, and the connecting piece 120 connects the fastening joint 114 and the end plate assembly. That is, in this embodiment, both ends of the pull rod 112 and the steel belt 113 are connected with a fastening joint 114, so that the pull rod 112 and the steel belt 113 can be arranged on the end plate assembly through the same structure, and there is no need to distinguish them during design, thereby improving versatility.

[0059] Example 2

[0060] Based on the same inventive concept, this embodiment provides a fuel cell system, including the fuel cell stack of Embodiment 1. The fuel cell stack, high-voltage components, low-voltage components, and housing together constitute a fuel cell module. This fuel cell system naturally has all the beneficial effects of the above-mentioned fuel cell stack, which will not be repeated here.

[0061] In order to cooperate with the fuel cell module, the fuel cell system also includes a fuel cell auxiliary system. The fuel cell system can operate normally under the condition of an external fuel supply source.

[0062] The fuel cell auxiliary system includes an air supply subsystem, a fuel supply subsystem, a thermal management subsystem, and an automatic control system. The air supply subsystem is used to supply air to each fuel cell module stack and can optionally filter, humidify, and pressure-regulate the air. The air supply subsystem is connected to the air inlet and air outlet of each fuel cell module stack. The fuel supply subsystem is used to supply fuel to each fuel cell module stack and can optionally humidify and pressure-regulate the fuel to convert it into fuel gas suitable for operation within the fuel cell stack. Taking hydrogen as the fuel, for example, the fuel supply subsystem is connected to the hydrogen inlet and hydrogen outlet of each fuel cell module stack. The thermal management subsystem is connected to each fuel cell module stack to provide coolant to cool and / or heat the stack and to recycle water generated by the stack. The automatic control system is electrically connected to the fuel cell module, air supply subsystem, fuel supply subsystem, and thermal management subsystem. The automatic control system is an assembly of sensors, actuators, valves, switches, and control logic components that ensure the normal operation of the fuel cell system without human intervention. In other embodiments, the fuel cell auxiliary system may further include a ventilation system for mechanically discharging gas from the fuel cell system housing to the exterior. The fuel cell auxiliary system in this embodiment has not been modified, so further details are provided in the relevant prior art disclosures and are not further described here.

[0063] Other structures of the fuel cell system not mentioned in this embodiment can be referred to in the prior art and will not be described in detail in this embodiment. For example, the fuel cell system also includes a housing having a mounting cavity, and the fuel cell stack is encapsulated in the mounting cavity of the housing. For example, in some embodiments, it also includes a high-voltage component, a gas distribution component, and a voltage inspection device to output current.

[0064] Example 3

[0065] Based on the same inventive concept, the present invention also provides a vehicle including the fuel cell system of Example 2. This vehicle naturally possesses all the beneficial effects of the fuel cell stack of Example 1. The present invention does not specifically limit the type or type of vehicle; it can be any vehicle known in the art, such as a family car, a passenger car, a truck, etc. Other structures of the vehicle not described in detail can be referred to the relevant disclosures in the prior art and will not be described in detail here.

[0066] The vehicle also includes a DC / DC converter, a drive motor and its motor controller, and an onboard energy storage device, which together with the fuel cell system form a fuel cell power system. The DC / DC converter is electrically connected to each fuel cell stack in the fuel cell system to achieve voltage conversion, regulating the voltage generated by each stack and outputting it to high-voltage components such as the drive motor and the vehicle air conditioning compressor, as well as energy storage devices such as batteries. The drive motor is electrically connected to the DC / DC converter to provide the torque required for vehicle operation. The motor controller is electrically connected to the drive motor to control its start, stop, and torque output. The motor controller is connected to the vehicle control system to receive driving signals from the vehicle control system and can optionally be electrically connected to the fuel cell system's automatic control system. The onboard energy storage device, for example, a battery, is used to store electrical energy to power other electronic devices within the vehicle and is electrically connected to the DC / DC converter.

[0067] In this embodiment, the DC / DC converter, the drive motor and its motor controller, and the on-board energy storage device in the fuel cell power system have not been improved. Therefore, for more detailed information, please refer to the relevant disclosures of the prior art and will not be described in detail here.

[0068] In addition, the vehicle also needs to include a transmission system and a fuel storage device for storing fuel. The transmission system transmits the torque of the drive motor to drive the wheels to rotate. The fuel storage device acts like a fuel tank in a fuel vehicle. The fuel storage device is connected to the fuel supply subsystem of the fuel cell system through a pipeline.

[0069] Thus, the vehicle can be a hydrogen-powered vehicle or a hydrogen-powered + rechargeable hybrid electric vehicle. Since this embodiment does not improve the specific structure of the vehicle, the unchanged structural features of the vehicle in this embodiment can refer to the existing technology and the details are not described in detail here. Therefore, the vehicle has all the features and advantages described above for the fuel cell module, and no further details are given here.

[0070] In summary, the fuel cell stack, fuel cell system and vehicle provided by the present invention adopt a fuel cell stack solution with the smallest volume and a combination of two fastening methods, namely, a pull rod and a steel belt, which is adapted to dumbbell-shaped bipolar plates. On the one hand, by designing the end plate assembly to a shape and size that matches the shape of the special-shaped bipolar plate, the space occupied by the end plate in the long side direction is reduced, the end plate size is minimized, and the power volume of the fuel cell stack is maximized. On the other hand, by utilizing the recessed space in the middle of the end plate assembly, the thickness of the fastening unit connected to the middle is designed to be greater than the thickness of the fastening unit connected to the end. The main fastening force is provided by the fastening unit with larger thickness and higher strength, and the fastening unit at the end provides auxiliary fastening force and is used to seal the core. According to the force requirements of the core, different fastening forces of different sizes are provided through different fastening schemes. The two fastening methods in the middle and the end each have their own emphasis, taking into account both the fastening and sealing of the fuel cell stack, and balancing the force conditions of the reaction zone as much as possible.

[0071] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0072] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A fuel cell stack, characterized in that: include, An end plate assembly, comprising at least two end plates, the at least two end plates being an intake end plate and a blind end plate assembly, respectively, the at least two end plates being distributed at both ends of the fuel cell stack; the width of the middle portion of the end plate being smaller than the width of the two end portions of the end plate; a fastening assembly comprising at least three fastening units, both ends of the at least three fastening units being connected to the end plate assembly and distributed at the middle portion and the end portions of the end plate; the thickness of the fastening units connected to the middle portion being greater than the thickness of the fastening units connected to the end portions; The fastening unit includes a fastener; or the fastening unit includes a fastener and an insulating support member, and the insulating support member is arranged between the core of the fuel cell stack and the fastener; The fastener is a pull rod and / or a steel belt, and both ends of the fastener are connected to the air intake end plate and the blind end plate assembly respectively; The fasteners connected to the middle portion are pull rods, and the number of the pull rods is at least 4; the fasteners connected to the end portions are steel belts.

2. The fuel cell stack according to claim 1, wherein: The fastening assembly includes at least six fastening units, and the at least six fastening units are distributed on at least two opposite sides of the fuel cell stack; two ends of the fastening units are respectively connected to the intake end plate and the blind end plate assembly.

3. The fuel cell stack according to claim 1, wherein: The outer side surface of the pull rod and the outer side surface of the steel belt located on the same side surface of the end plate assembly are coplanar.

4. The fuel cell stack according to any one of claims 1 to 3, wherein: Both ends of the end plate are connected to the fastening units, and at least one of the fastening units connected to the ends includes a fastener and an insulating support member, and the insulating support member has a bending portion extending to the adjacent short side or long side of the core of the fuel cell stack, which is used to limit the core.

5. The fuel cell stack according to claim 4, wherein: The fastening unit is provided on both the long side and the short side of the end portion; The fastening unit connected to the long side of the end portion includes a fastener and an insulating support; the fastening unit connected to the short side of the end portion includes a fastener.

6. The fuel cell stack according to claim 4, wherein: A limiting structure is provided on the fastener and / or the insulating support, and the fastener and the insulating support are positioned by the limiting structure; and / or the insulating support has a recessed groove, and the fastener is interference fit with the recessed groove.

7. The fuel cell stack according to claim 4, wherein: The fastening assembly further includes a connector for connecting the fastening unit and the end plate assembly; the fastening unit further includes fastening joints respectively connected to both ends of each fastening unit, and the connector connects the fastening joint and the end plate assembly.

8. The fuel cell stack according to any one of claims 1 to 3, wherein: The fuel cell stack further includes an air intake end collecting plate and a blind end collecting plate, wherein the width of the middle portions of the air intake end collecting plate and the blind end collecting plate is smaller than the width of the two end portions of the end plates.

9. A fuel cell system, characterized in that: Comprising the fuel cell stack according to any one of claims 1 to 6.

10. A vehicle, characterized in that: A fuel cell system comprising the fuel cell system according to claim 9.

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