A fuel cell stack assembly and fuel cell system

Abstract

The present application relates to a kind of fuel cell stack and fuel cell system, belong to fuel cell technical field.The fuel cell stack includes fuel cell stack, the fuel cell stack is sequentially arranged, and the electrically conductive connecting component is arranged between two adjacent fuel cell stacks, and two adjacent fuel cell stacks are electrically connected by the electrically conductive connecting component, the second end plate of one fuel cell stack in two adjacent fuel cell stacks and the first surface of the electrically conductive connecting component are electrically contacted, and the first end plate of another fuel cell stack and the second surface of the electrically conductive connecting component are electrically contacted, the first surface and second surface are opposite, and the material of the first surface and the material of the second surface are flexible conductive material.The structure of the fuel cell stack is reasonable, and the first surface and the second surface can be appropriately deformed under pressure, so that the electrically conductive connecting component and the end plate of fuel cell stack maintain good electrical connection, so that the internal conduction of fuel cell system is good.

Description

TECHNICAL FIELD

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

[0002] Fuel cell is a kind of energy conversion device that can directly convert chemical energy stored in fuel and oxidant into electrical energy. Since the 1940s, four generations of fuel cells have been developed. The first generation of fuel cells is alkaline fuel cell (AFC) and phosphoric acid fuel cell (PAFC), the second generation of fuel cells is molten carbonate fuel cell (MCFC), the third generation of fuel cells is solid oxide fuel cell (SOFC), and the fourth generation of fuel cells is proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell. Among them, solid oxide fuel cell has a high working temperature, usually in the range of 800~1000℃, which can realize heat and power cogeneration while generating electricity, and the energy utilization efficiency can be as high as 90%.

[0003] In order to improve the power output, the prior art usually fixes and connects multiple solid oxide fuel cell stacks in sequence to form a fuel cell stack. The structure design of the existing fuel cell stack is unreasonable, and poor electrical contact is prone to occur during operation.

[0004] Therefore, it is necessary to design a fuel cell stack and a fuel cell system with good electrical contact. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a fuel cell stack and a fuel cell system. The structure of the fuel cell stack provided by the present application is reasonable. The present application sets a conductive connecting assembly between two adjacent fuel cell stacks. The first surface and the second surface of the conductive connecting assembly can be appropriately deformed under pressure, so that the conductive connecting assembly and the fuel cell stack maintain good electrical contact during system operation.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] In a first aspect, the present application provides a fuel cell stack group, comprising fuel cell stacks, the fuel cell stack comprising a first end plate, a single cell group and a second end plate, the single cell group being located between the first end plate and the second end plate; the fuel cell stacks are arranged in sequence, and a conductive connecting assembly is arranged between two adjacent fuel cell stacks, the two adjacent fuel cell stacks being electrically connected through the conductive connecting assembly, the second end plate of one of the two adjacent fuel cell stacks being in electrical contact with a first surface of the conductive connecting assembly, and the first end plate of the other fuel cell stack being in electrical contact with a second surface of the conductive connecting assembly, the first surface and the second surface being opposite to each other, and the material of the first surface and the material of the second surface being flexible conductive materials.

[0008] The fuel cell stack group provided by the present application has a reasonable structure design, the two adjacent fuel cell stacks are electrically connected through the conductive connecting assembly, and the first surface and the second surface of the conductive connecting assembly are both flexible conductive materials. Such materials not only have good high-temperature oxidation resistance and high-temperature stability, but also have high interface strength and strong anti-shock ability. Compared with rigid conductive materials, the first surface and the second surface of the flexible conductive materials of the present application can deform appropriately under the pressure generated by the self-weight of the fuel cell stack during the operation of the fuel cell system, so that the conductive connecting assembly and the fuel cell stack maintain good electrical connection. Therefore, the conductive connecting assembly is more suitable for internal conduction of the fuel cell system.

[0009] As a preferred embodiment of the present application, the flexible conductive material comprises any one of an alloy, a single-element metal and an inorganic metal oxide; the alloy comprises any one of an iron-based alloy and a nickel-based alloy; the single-element metal comprises any one of silver, gold, copper and aluminum; and the inorganic metal oxide comprises any one of La x Sr 1-x MnO3, La x Sr 1-x CoO3, La x Sr 1- x Co y Fe 1-y O3, wherein 0

[0010] As a preferred embodiment of the present application, the elastic modulus of the flexible conductive material at 500-1200℃ is 1-500GPa, and is further preferably 1-100GPa; the ratio of the Brinell hardness between the flexible conductive material and the material of the first end plate is 0.01-0.8, and the ratio of the Brinell hardness between the flexible conductive material and the material of the second end plate is 0.01-0.8.

[0011] It is found through research that the elastic modulus of the flexible conductive material will affect the performance of the fuel cell stack due to the fuel cell working at high temperature and high pressure. If the elastic modulus of the flexible conductive material at 500-1200℃ is less than 1GPa, the first surface and the second surface have a risk of damage during the process of the fuel cell stack being applied with a pressure; if the elastic modulus of the flexible conductive material at 500-1200℃ is greater than 500GPa, the deformation of the first surface and the second surface under the action of external force is too small, which is not conducive to the conductive effect of the conductive connecting assembly between two adjacent fuel cell stacks. If the elastic modulus of the flexible conductive material at 500-1200℃ is 1-100GPa, the first surface and the second surface can appropriately deform under the pressure generated by the self-weight of the fuel cell stack, so that the conductive connecting assembly and the fuel cell stack can also maintain good electrical contact under high temperature and high pressure.

[0012] It is found through research that if the ratio of the Brinell hardness is greater than 0.8, the hardness of the flexible conductive material is relatively large, which will affect the conductive effect between the conductive connecting assembly and the fuel cell stack; if the ratio of the Brinell hardness is less than 0.01, the self-weight pressure of the fuel cell stack is easy to locally damage the first surface and the second surface during assembly or system operation, so that the conductive effect between the conductive connecting assembly and the fuel cell stack becomes poor.

[0013] As a preferred embodiment of the present application, the first surface is A, the second surface is B, the side surface of the first end plate in contact with the second surface is C, and the side surface of the second end plate in contact with the first surface is D. A, B, C and D at least satisfy one of the following conditions: (1) the area ratio between A and D is 0.1-0.99, and is further preferably 0.3-0.95; (2) the area ratio between B and C is 0.1-0.99, and is further preferably 0.3-0.95.

[0014] It is found through research that if the area ratio between A and D is less than 0.1 or the area ratio between B and C is less than 0.1, the electric conduction efficiency between the conductive connecting assembly and the fuel cell stack will be reduced, the conductive effect is poor, and the power generation efficiency of the fuel cell system is further reduced; if the area ratio between A and D is greater than 0.99 or the area ratio between B and C is greater than 0.99, the cost of the conductive connecting assembly is relatively increased under the condition that the specifications of the fuel cell stack are unchanged, and it is more difficult to control the position of the conductive connecting assembly during assembly, which increases the assembly difficulty.

[0015] As a preferred embodiment of the present application, two adjacent fuel cell stacks and the conductive connecting assembly are connected through a positioning pin; the first end plate, the second end plate and the conductive connecting assembly are all provided with a positioning hole, and the positioning pin is inserted into the positioning hole.

[0016] It can be understood that the existing structure design of the fuel cell stack group is unreasonable, inconvenient to install and disassemble, and the assembly position between two adjacent fuel cell stack units is prone to inaccuracy during assembly. Moreover, due to the large overall volume and height of the fuel cell system, inaccurate assembly can cause abnormal operation of the fuel cell system, and even dangerous working conditions such as electric leakage. In order to solve the above problems, the present application cooperates the positioning pin and the positioning hole to make the assembly and disassembly of the fuel cell stack group more convenient, and the positioning pin is used to assemble the conductive connecting assembly and the corresponding fuel cell stack together, which can effectively ensure the assembly accuracy of the fuel cell stack group.

[0017] Further, the total thickness of the conductive connecting assembly is H, and the length of the positioning pin is L, and H and L satisfy: 1≤L / H≤2.6. It is found through research that if L / H is less than 1, the length of the positioning pin is relatively insufficient, and at least one end of the positioning pin is difficult to be inserted into the positioning hole of the corresponding end plate, so that the positioning and fixing of the conductive connecting assembly and the corresponding fuel cell stack cannot be effectively ensured during assembly, thereby increasing the probability of installation error caused by inaccurate assembly. If L / H is greater than 2.6, under the premise that the specification of the fuel cell stack is fixed, the length of the positioning pin is relatively too long, which increases the assembly difficulty.

[0018] As a preferred embodiment of the present application, the conductive connecting assembly comprises a conductive element, the conductive element comprises at least one conductive sheet, the material of the conductive sheet is a flexible conductive material, the first surface is the surface of the conductive element in contact with the second end plate, and the second surface is the surface of the conductive element in contact with the first end plate.

[0019] It can be understood that the present application does not particularly limit the number of conductive sheets in the conductive element.

[0020] The conductive element of the present application can be one conductive sheet, and the first surface and the second surface are two opposite surfaces of the conductive sheet.

[0021] The conductive element of the present application can also be formed by sequentially arranging at least two conductive sheets; and the air guide seat is inserted between any two adjacent conductive sheets.

[0022] It can be understood that the present application does not particularly limit the cross-sectional shape of the conductive sheet. The cross-sectional shape can be a regular shape or an irregular shape. The regular shape can be any one of a rectangle, a parallelogram, an isosceles trapezoid, a circle, an ellipse, and a regular polygon.

[0023] Further, the thickness of the conductive sheet is h, and h satisfies 0.05mm≤h≤0.7mm. If the thickness of the conductive sheet is less than 0.05mm, the two adjacent fuel cell stacks are prone to assembly tilt due to the difference in flatness of the conductive sheet, and the effective contact between the conductive sheet and the corresponding end plate is affected. If the thickness of the conductive sheet is greater than 0.7mm, the cost of the conductive element is significantly increased, and the effective contact between the conductive element and the corresponding end plate is affected, resulting in poor contact between the conductive sheet and the corresponding end plate and the generation of gaps, which affects the air distribution of each fuel cell stack in the system.

[0024] As a preferred embodiment of the present application, the first end plate of the fuel cell stack is provided with a gas hole, the conductive connecting assembly comprises a gas guide piece, the conductive connecting assembly comprises a gas guide piece, and the gas guide piece is used to guide the gas into the gas hole. In two adjacent fuel cell stacks, the gas guide piece is located between the first surface and the second surface, and the material of the gas guide piece is a conductive material.

[0025] Further, the gas guide piece is provided with a gas guide hole corresponding to the gas hole, one end of the gas guide hole is in sealed communication with the gas hole through a sealing piece, and the other end of the gas guide hole is connected with a gas pipe.

[0026] The structure design of the fuel cell stack group in the prior art is unreasonable, and the gas holes between the two adjacent fuel cell stacks are in one-to-one corresponding communication, so that the gas flow into each fuel cell stack is greatly different, and the gas utilization rate is low. In view of this problem, the fuel cell stack group of the present application is provided with a gas guide piece. The gas pipe comprises a gas input pipe and a gas output pipe, the gas input pipe is used to deliver gas to the fuel cell stack, and the gas output pipe is used to discharge the gas discharged from the fuel cell stack. The gas holes are divided into two groups: one group is used to input gas into the fuel cell stack and is in communication with the gas input pipe through the corresponding gas guide hole and sealing piece; the other group is used to discharge the gas from the fuel cell stack and is in communication with the gas output pipe through the corresponding gas guide hole and sealing piece. The gas can enter the fuel cell stack through the gas guide piece and the gas input pipe, and the gas discharged from each fuel cell stack is discharged from the system through the gas guide piece and the gas output pipe, so that the gas input flow difference between each fuel cell stack is small, the gas output flow difference is also small, and the gas utilization rate is effectively improved.

[0027] The gas input pipe and the gas output pipe are both connected by a plurality of gas single pipes through flanges and sealing washers in sequence, which is convenient to install and disassemble. The sealing washers can effectively ensure the sealing of gas delivery and can effectively avoid safety accidents caused by gas leakage.

[0028] Further, the material of the sealing member is any one of rubber, ceramic, glass, sealing cotton and mica. If the material of the sealing member is any one of ceramic, glass and mica, the sealing member made of such material has no elasticity, one end of the sealing member is in close contact with the first end plate, the other end of the sealing member is in close contact with the air guide member, the arrangement of the sealing member does not affect the effective contact between the conductive element and the first end plate, and the risk of gas leakage is greatly reduced.

[0029] Further, the air guide member comprises an air guide seat located between the first surface and the second surface, both sides of the air guide seat are provided with ear seats, the ear seats are provided with air grooves penetrating through the two opposite surfaces of the ear seats, the air guide seat is integrally connected with the ear seat, and the air guide hole extends from the side surface of the air guide seat close to the first end plate to the inner wall surface of the air groove of the ear seat.

[0030] In the application, the conductive element is preferably formed by sequentially arranging at least two conductive sheets, and the air guide seat is inserted between two adjacent conductive sheets.

[0031] In the second aspect, the application provides a fuel cell system, which comprises the fuel cell stack group in the first aspect, and further comprises a housing and an electricity leading mechanism; the fuel cell stack group is arranged in the housing, an insulating part is arranged between the inner wall of the housing and the fuel cell stack group, one end of the electricity leading mechanism is exposed outside the housing, and the other end of the electricity leading mechanism is electrically connected with the fuel cell stack group through a conductive connecting assembly.

[0032] In the application, the insulating part is arranged between the inner wall of the housing and the fuel cell stack group, so that high voltage and high current are generated when the fuel cell system works, and if the insulating part is not arranged, a safety accident is likely to occur.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] The fuel cell stack group provided by the application has a reasonable structure design, two adjacent fuel cell stacks are electrically connected through the conductive connecting assembly, the first surface and the second surface of the conductive connecting assembly are made of flexible conductive material, such material has good high-temperature oxidation resistance and high-temperature stability, has high interface strength and strong anti-shock capacity, and in the process of operation of the fuel cell system, the first surface and the second surface can be deformed under the pressure generated by the self-weight of the fuel cell stack, so that the conductive connecting assembly and the fuel cell stack are kept in good electrical connection, and the internal conduction of the fuel cell system is good. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1A perspective view of the fuel cell stack provided by the present application;

[0036] Figure 2 An exploded schematic view of the fuel cell stack and the electrically conductive connecting assembly provided by the present application;

[0037] Figure 3 A perspective view of the electrically conductive connecting assembly and the positioning pin provided by the present application;

[0038] Figure 4 A front view of the electrically conductive connecting assembly and the positioning pin provided by the present application;

[0039] Figure 5 An enlarged schematic view of the a portion in Figure 4

[0040] Figure 6 A schematic view of the connection between the air guide and the gas pipe provided by the present application;

[0041] Figure 7 A perspective view of the fuel cell system provided by the present application;

[0042] Figure 8 A perspective view of the fuel cell system after the shell is removed provided by the present application.

[0043] In the figure, 1 - fuel cell stack, 11 - first end plate, 12 - single cell group, 13 - second end plate, 14 - gas hole, 2 - electrically conductive element, 3 - positioning pin, 4 - air guide, 41 - air guide hole, 42 - air guide seat, 43 - ear seat, 44 - empty slot, 5 - sealing element, 6 - gas pipe, 61 - gas input pipe, 62 - gas output pipe, 7 - shell, 8 - electricity leading mechanism, 9 - insulating part. DETAILED DESCRIPTION

[0044] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific embodiments.

[0045] Embodiment 1

[0046] The present embodiment provides a fuel cell stack, the structure of which is shown in Figures 1-2

[0047] ​​The fuel cell stack group comprises at least two fuel cell stacks 1, each fuel cell stack 1 comprising a first end plate 11, a single cell group 12 and a second end plate 13, the single cell group 12 being located between the first end plate 11 and the second end plate 13 and being composed of a plurality of single cells stacked in sequence; the fuel cell stacks 1 are arranged in sequence, and a conductive connecting assembly is arranged between any two adjacent fuel cell stacks 1 in the arrangement direction, the two adjacent fuel cell stacks 1 being electrically connected through the conductive connecting assembly, the second end plate 13 of one of the two adjacent fuel cell stacks 1 being in electrical contact with a first surface of the conductive connecting assembly, and the first end plate 11 of the other fuel cell stack 1 being in electrical contact with a second surface of the conductive connecting assembly, the first surface and the second surface being opposite to each other, and the material of the first surface and the material of the second surface being flexible conductive materials.

[0048] The fuel cell stack group provided by the embodiment has a reasonable structure design, the two adjacent fuel cell stacks 1 are electrically connected through the conductive connecting assembly, and the first surface and the second surface of the conductive connecting assembly are both flexible conductive materials, which have good high-temperature oxidation resistance and high-temperature stability, high interface strength and strong anti-shock capability; compared with rigid conductive materials, the first surface and the second surface of the flexible conductive materials can deform appropriately under the pressure generated by the self-weight of the fuel cell stack 1 during the operation of the fuel cell system, so that the conductive connecting assembly and the fuel cell stack 1 maintain good electrical connection, and therefore, the conductive connecting assembly is more suitable for internal conduction of the fuel cell system.

[0049] The flexible conductive material comprises any one of an alloy, a single-element metal and an inorganic metal oxide; the alloy comprises any one of an iron-based alloy and a nickel-based alloy; the single-element metal comprises any one of silver, gold, copper and aluminum; and the inorganic metal oxide comprises any one of La x Sr 1-x MnO3, La x Sr 1-x CoO3, La x Sr 1-x Co y Fe 1-y O3, wherein 0 < x < 1 and 0 < y < 1.

[0050] The elastic modulus of the flexible conductive material at 500-1200℃ is 1-500 GPa, and is further preferably 1-100 GPa. It has been found through research that, since the fuel cell operates at high temperature and high pressure, the elastic modulus of the flexible conductive material affects the performance of the fuel cell stack 1. If the elastic modulus of the flexible conductive material at 500-1200℃ is less than 1 GPa, the first surface and the second surface are at risk of being damaged during the process of applying pressure to the fuel cell stack 1. If the elastic modulus of the flexible conductive material at 500-1200℃ is greater than 500 GPa, the deformation of the first surface and the second surface under external force is too small, which is not conducive to the conductive effect of the conductive connecting assembly between two adjacent fuel cell stacks 1. If the elastic modulus of the flexible conductive material at 500-1200℃ is 1-100 GPa, the first surface and the second surface can appropriately deform under the pressure generated by the self-weight of the fuel cell stack 1, and the conductive connecting assembly can maintain good electrical contact with the fuel cell stack 1 at high temperature and high pressure.

[0051] The material of the first end plate 11 and the material of the second end plate 12 are both conductive materials, and the ratio of the Brinell hardness between the flexible conductive material and the material of the first end plate 11 is 0.01-0.8, and the ratio of the Brinell hardness between the flexible conductive material and the material of the second end plate 12 is 0.01-0.8. It has been found through research that, if the ratio of the Brinell hardness is greater than 0.8, the hardness of the flexible conductive material is relatively large, which affects the conductive effect between the conductive connecting assembly and the fuel cell stack 1. If the ratio of the Brinell hardness is less than 0.01, the self-weight pressure of the fuel cell stack 1 easily locally damages the first surface and the second surface during assembly or system operation, which makes the conductive effect between the conductive connecting assembly and the fuel cell stack 1 worse.

[0052] The first surface is A, the second surface is B, the side surface of the first end plate 11 in contact with the second surface is C, and the side surface of the second end plate 12 in contact with the first surface is D. A, B, C and D at least satisfy one of the following conditions: (1) the area ratio between A and D is 0.1-0.99, and is further preferably 0.3-0.95; (2) the area ratio between B and C is 0.1-0.99, and is further preferably 0.3-0.95. It has been found through research that, if the area ratio between A and D is less than 0.1 or the area ratio between B and C is less than 0.1, the electrical conduction efficiency between the conductive connecting assembly and the fuel cell stack 1 is reduced, the conductive effect is poor, and the power generation efficiency of the fuel cell system is further reduced. If the area ratio between A and D is greater than 0.99 or the area ratio between B and C is greater than 0.99, the cost of the conductive connecting assembly relatively increases under the condition that the specifications of the fuel cell stack 1 remain unchanged, and it is more difficult to control the position of the conductive connecting assembly during assembly, which increases the assembly difficulty.

[0053] In the embodiment, the conductive connecting assembly comprises a conductive element 2, the conductive element 2 comprises at least one conductive sheet, the material of the conductive sheet is a flexible conductive material, the first surface is a surface of the conductive element 2 which is in contact with the second end plate 12, and the second surface is a surface of the conductive element 2 which is in contact with the first end plate 11.

[0054] It can be understood that, in the embodiment, the conductive element 2 can be one conductive sheet, and the first surface and the second surface are two opposite surfaces of the conductive sheet. The conductive element 2 can also be formed by sequentially arranging at least two conductive sheets, the first surface is a surface of the conductive sheet located at the head which is in contact with the second end plate 12, and the second surface is a surface of the conductive sheet located at the tail which is in contact with the first end plate 11.

[0055] It can be understood that the present application does not particularly limit the cross-sectional shape of the conductive sheet. The cross-sectional shape can be a regular shape or an irregular shape. The regular shape can be any one of a rectangle, a parallelogram, an isosceles trapezoid, a circle, an ellipse, and a regular polygon.

[0056] The thickness of the conductive sheet is h, and h satisfies 0.05 mm≤h≤0.7 mm. If the thickness h of the conductive sheet is less than 0.05 mm, when assembling, two adjacent fuel cell stacks 1 have different flatnesses due to the too small thickness of the conductive sheet, and the assembly inclination problem is prone to occur, and the effective contact between the conductive sheet and the corresponding end plate is also affected. If the thickness h of the conductive sheet is greater than 0.7 mm, the cost of the conductive element 2 is significantly increased, and the too large thickness h of the conductive sheet affects the effective contact between the conductive element 2 and the corresponding end plate, resulting in poor contact between the conductive sheet and the corresponding end plate and the generation of a gap, and the generation of the gap affects the air distribution of each fuel cell stack 1 in the system.

[0057] In the embodiment, two adjacent fuel cell stacks 1 and the conductive connecting assembly are connected through a positioning pin 3, the first end plate 11, the second end plate 12 and the conductive connecting assembly are all provided with positioning holes, and the positioning pin 3 is inserted into the positioning holes. The assembly and disassembly of the fuel cell stack group are more convenient through the cooperation of the positioning pin 3 and the positioning holes, and the assembly precision of the fuel cell stack group can be effectively ensured by assembling the conductive connecting assembly and the corresponding fuel cell stack 1 together through the positioning pin 3.

[0058] The total thickness of the conductive connecting assembly is H, and the length of the positioning pin 3 is L, and H and L satisfy: 1≤L / H≤2.6. It is found through research that if L / H is less than 1, the length of the positioning pin 3 is relatively insufficient, and at least one end thereof is difficult to be inserted into the positioning hole of the corresponding end plate, so that the positioning and fixing of the conductive connecting assembly and the corresponding fuel cell stack 1 cannot be effectively ensured during assembly, thereby increasing the probability of occurrence of installation error problems due to inaccurate assembly. If L / H is greater than 2.6, the length of the positioning pin 3 is relatively too long under the premise that the specification of the fuel cell stack 1 is unchanged, thereby increasing the assembly difficulty.

[0059] Embodiment 2

[0060] The fuel cell stack group provided in the present embodiment is an improvement based on Embodiment 1, and the content disclosed in Embodiment 1 will not be described again, and the content disclosed in Embodiment 1 also belongs to the content disclosed in the present embodiment.

[0061] Please refer to Figures 1-6 As shown in the figure, the first end plate 11 of the fuel cell stack 1 is provided with a gas hole 14, the conductive connecting assembly comprises a gas guide member 4, and the gas guide member 4 is used for guiding gas into the gas hole 14; in two adjacent fuel cell stacks 1, the gas guide member 4 is located between the first surface and the second surface, and the material of the gas guide member 4 is a conductive material.

[0062] The gas guide member 4 is provided with a gas guide hole 41 corresponding to the gas hole 14, one end of the gas guide hole 41 is in sealed communication with the gas hole 14 through a sealing member 5, and the other end of the gas guide hole 41 is in communication with a gas pipe 6.

[0063] The gas guide member 4 is made of a conductive material, the gas guide member 4 comprises a gas guide seat 42, the gas guide seat 42 is located between the first surface and the second surface, and the positioning hole of the conductive connecting assembly penetrates through the gas guide seat 42 and the conductive element 2; both sides of the gas guide seat 42 are provided with an ear seat 43, the ear seat 43 is provided with a hollow groove 44, the hollow groove 44 penetrates through the two opposite surfaces of the ear seat 43, the gas guide seat 42 and the ear seat 43 are integrally connected, the gas guide hole 41 extends from the side surface of the gas guide seat 42 close to the first end plate 11 to the inner wall surface of the hollow groove 44, and the gas pipe 6 is inserted into the hollow groove of the ear seat 43 and is in communication with the gas guide hole 41.

[0064] In the present embodiment, the conductive element 2 is arranged by at least two conductive sheets in sequence, and the gas guide seat 42 is inserted between the two adjacent conductive sheets. As shown in the figure, Figures 2-5 The conductive element 2 is arranged by two conductive sheets, and the gas guide seat 42 is inserted between the two conductive sheets.

[0065] The gas pipe 6 includes a gas inlet pipe 61 and a gas outlet pipe 62. The gas inlet pipe 61 is used to supply gas to the fuel cell stack 1, and the gas outlet pipe 62 is used to discharge the gas discharged from the fuel cell stack 1. The gas outlets 14 are divided into two groups: one group is used to input gas into the fuel cell stack 1, and is connected to the gas supply pipe 61 through the corresponding vent 41 and sealing element 5; the other group is used to discharge gas from the fuel cell stack 1, and is connected to the gas outlet pipe 62 through the corresponding vent 41 and sealing element 4. Gas can enter the fuel cell stack 1 through the vent 4 and the gas inlet pipe 61, and the gas discharged from each fuel cell stack 1 can be discharged through the vent 4 and the gas outlet pipe 62, so that the difference in gas input flow rate and gas output flow rate between each fuel cell stack 1 is small, thereby effectively improving the gas utilization rate.

[0066] Both the gas inlet pipe 61 and the gas outlet pipe 62 are composed of several gas single pipes connected in sequence by flanges and sealing gaskets. They are easy to install and disassemble. The sealing gaskets can effectively ensure the sealing of the gas transmission and can effectively prevent safety accidents caused by gas leakage.

[0067] The material of the sealing element 5 can be any one of rubber, ceramic, glass, sealing cotton, or mica. If the material of the sealing element 5 is any one of ceramic, glass, or mica, the sealing element of this type of material is not elastic. One end of the sealing element 5 is in close contact with the first end plate 11, and the other end of the sealing element 5 is in close contact with the gas guide 4. The setting of the sealing element 5 will not affect the effective contact between the conductive element 2 and the first end plate 11, which greatly reduces the risk of gas leakage.

[0068] Example 3

[0069] This embodiment provides a fuel cell system, the structure of which is as follows: Figures 1-8 As shown. The fuel cell system includes the fuel cell stack described in Example 2.

[0070] The fuel cell system also includes a housing 7 and an electric inlet mechanism 8. The fuel cell stack is disposed inside the housing 7. One end of the electric inlet mechanism 8 is exposed outside the housing 7. The other end of the electric inlet mechanism 8 is electrically connected to the fuel cell stack 1 located at the first end by a conductive connection component. The electric inlet mechanism 8 and the fuel cell stack are electrically connected through the conductive connection component.

[0071] An insulating component 9 is provided between the housing 7 and the fuel cell stack. The insulating component 9 is provided between the housing 7 and the fuel cell stack to ensure that the fuel cell system generates high voltage and high current during operation. Without the insulating component 9, safety accidents could easily occur.

[0072] One end of the gas pipe 6 extends out of the housing 7 and is connected to an external gas source.

[0073] Finally, it should be noted that the above examples are merely intended to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A fuel cell stack group characterized by comprising: The fuel cell stack comprises a first end plate, a single cell group and a second end plate, and the single cell group is located between the first end plate and the second end plate; the fuel cell stack is arranged in sequence, and a conductive connecting assembly is arranged between two adjacent fuel cell stacks, the two adjacent fuel cell stacks are electrically connected through the conductive connecting assembly, the second end plate of one of the two adjacent fuel cell stacks is in electrical contact with a first surface of the conductive connecting assembly, and the first end plate of the other fuel cell stack is in electrical contact with a second surface of the conductive connecting assembly, the first surface and the second surface are opposite, and the material of the first surface and the material of the second surface are flexible conductive materials; The first end plate of the fuel cell stack is provided with a gas hole, the conductive connecting assembly comprises a gas guide piece, and the gas guide piece is used for guiding gas into the gas hole; the gas guide piece is provided with a gas guide hole corresponding to the gas hole, one end of the gas guide hole is in sealed communication with the gas hole through a sealing piece, and the other end of the gas guide hole is connected with a gas pipe of a fuel cell system.

2. The fuel cell stack assembly of claim 1, wherein The flexible conductive material includes any one of an alloy, a single metal and an inorganic metal oxide; the alloy includes any one of an iron-based alloy and a nickel-based alloy; the single metal includes any one of silver, gold, copper and aluminum; and the inorganic metal oxide includes any one of La x Sr 1-x MnO3, La x Sr 1-x CoO3, La x Sr 1-x Co y Fe 1-y O3, wherein 0 3. The fuel cell stack assembly of claim 1 wherein, The elastic modulus of the flexible conductive material at 500-1200 DEG C is 1-500 GPa.

4. The fuel cell stack assembly of claim 1 wherein, The ratio of the Brinell hardness between the flexible conductive material and the material of the first end plate is 0.01-0.8, and the ratio of the Brinell hardness between the flexible conductive material and the material of the second end plate is 0.01-0.

8.

5. The fuel cell stack assembly of claim 1 wherein, The first surface is A, the second surface is B, one side surface of the first end plate in contact with the second surface is C, one side surface of the second end plate in contact with the first surface is D, and A, B, C and D at least meet one of the following conditions: (1) the area ratio between A and D is 0.1-0.99, and (2) the area ratio between B and C is 0.1-0.

99.

6. The fuel cell stack assembly of claim 1 wherein, The two adjacent fuel cell stacks and the conductive connecting assembly are connected through a positioning pin; the first end plate, the second end plate and the conductive connecting assembly are all provided with positioning holes, and the positioning pin is inserted into the positioning holes.

7. The fuel cell stack assembly of claim 6 wherein, The total thickness of the conductive connecting assembly is H, and the length of the positioning pin is L, and H and L satisfy: 1≤L / H≤2.

6.

8. The fuel cell stack assembly of claim 1 wherein, In the two adjacent fuel cell stacks, the gas guide piece is located between the first surface and the second surface, and the material of the gas guide piece is a conductive material.

9. A fuel cell system characterized by comprising: The fuel cell stack group comprises a housing and an electricity leading mechanism; the fuel cell stack group is arranged in the housing, an insulating part is arranged between the inner wall of the housing and the fuel cell stack group, one end of the electricity leading mechanism is exposed outside the housing, the other end of the electricity leading mechanism extends into the housing and is provided with a conductive connecting assembly between the electricity leading mechanism and the fuel cell stack group, and the electricity leading mechanism and the fuel cell stack group are electrically connected through the conductive connecting assembly.

Images