fuel cell stack unit and fuel cell stack

Abstract

This invention discloses a fuel cell stack unit and a fuel cell stack. The fuel cell stack unit (100) includes a vertically stacked upper end plate (110), a battery cell group (120), and a lower end plate (130). The top surface (1) of the upper end plate (110) and the bottom surface (2) of the lower end plate (130) both include an interface connection part (200) and a conductive connection part (300). The upper end plate and the lower end plate are provided with a conductive connection part and adopt a sawtooth plug-in conductive mating structure, which not only ensures the conductive correlation between adjacent fuel cell stack units, increases the contact area between end plates, improves the contact effect, reduces the contact resistance, and enhances the conductivity, but also reserves space for gas sealing between adjacent fuel cell stack units, prevents leakage of anode gas and cathode gas, avoids potential combustion risks, allows each fuel cell stack unit to be stacked quickly, is easy to operate, ensures the sealing and conductivity between each fuel cell stack unit, and realizes the stable operation of the fuel cell stack.

Description

Technical Field

[0001] This invention belongs to the field of fuel power generation technology, specifically relating to a fuel cell stack unit and a fuel cell stack. Background Technology

[0002] Solid oxide fuel cells (SOFCs), as a third-generation fuel cell, are all-solid-state chemical power generation devices that efficiently and environmentally convert the chemical energy stored in fuel and oxidant into electrical energy directly at medium to high temperatures. SOFCs offer advantages such as wide fuel adaptability, high energy conversion efficiency, all-solid-state operation, modular assembly, and zero pollution. They can directly use various hydrocarbon fuels, including hydrogen, carbon monoxide, natural gas, liquefied petroleum gas, coal gas, and biomass gas. They have broad application prospects in civilian sectors such as large-scale centralized power supply, medium-sized distributed power supply, and small-scale residential combined heat and power (CHP) systems, as well as in mobile power sources such as ship propulsion and vehicle power.

[0003] A solid oxide fuel cell unit mainly consists of an electrolyte, an anode or fuel electrode, a cathode or air electrode, and connectors or bipolar plates. The stability of the fuel cell stack is crucial to the stable operation of the entire solid oxide fuel cell. Planar stationary oxide fuel cell stacks consist of multiple stacked units with a box-like structure. When multiple stack units are stacked, the operation is cumbersome, and the inter-unit connectivity is poor, which is detrimental to the stable operation of the fuel cell stack. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies of the prior art, the present invention provides a fuel cell stack unit and a fuel cell stack, which can be quickly stacked, is easy to operate, has high correlation, ensures the sealing and conductivity between the stack units, and realizes the stable operation of the fuel cell stack.

[0005] To achieve the above objectives, according to one aspect of the present invention, a battery stack unit is provided, the battery stack unit comprising a vertically stacked upper end plate, a battery cell group and a lower end plate, wherein the top surface of the upper end plate and the bottom surface of the lower end plate both include an interface connection portion and a conductive connection portion.

[0006] The conductive connection portion includes an upper end plate conductive connection portion formed on the top surface of the upper end plate and a lower end plate conductive connection portion formed on the bottom surface of the lower end plate. The upper end plate conductive connection portion can form a plug-in conductive fit with the vertically adjacent lower end plate conductive connection portion.

[0007] In some embodiments, one of the upper end plate conductive connection portion and the lower end plate conductive connection portion is a serrated member protruding from the end plate surface, and the other is a serrated hole recessed in the end plate surface. The serration height of the serrated member is greater than the hole depth of the serrated hole, so that an end plate spacing is formed between the vertically adjacent upper end plate and the lower end plate.

[0008] In some embodiments, the interface connection portion includes an upper end plate interface connection portion formed on the top surface of the upper end plate and a lower end plate interface connection portion formed on the bottom surface of the lower end plate, and the end plate spacing is formed between the upper end plate interface connection portion and the opposite lower end plate interface connection portion.

[0009] In some embodiments, the end plate spacing is filled with an end plate sealing layer, so that a gas-flowing sealed channel is formed between the vertically adjacent upper end plate interface connection portion and the lower end plate interface connection portion.

[0010] In some embodiments, the gas flow sealing channel includes an inlet sealing channel for guiding inlet gas and an outlet sealing channel for guiding outlet gas.

[0011] The upper end plate interface connection portion is provided with an upper end plate inlet port for forming the gas inlet of the fuel cell unit and an upper end plate outlet port for forming the gas outlet of the fuel cell unit. The lower end plate interface connection portion is provided with a lower end plate inlet port for forming the gas inlet of the fuel cell unit and a lower end plate outlet port for forming the gas outlet of the fuel cell unit. This forms an inlet sealing channel between the upper end plate inlet port and the corresponding lower end plate inlet port, and an outlet sealing channel between the upper end plate outlet port and the corresponding lower end plate outlet port.

[0012] In some embodiments, the inlet sealing channel and the outlet sealing channel are respectively located on both sides of the conductive connection portion.

[0013] In some embodiments, the end plate sealing layer is made of a high-temperature resistant material.

[0014] In some embodiments, a positioning component for fixing the adjacent fuel cell stack unit is further included between the top surface of the upper end plate and the bottom surface of the lower end plate. The positioning component includes an upper end plate positioning groove disposed on the top surface of the upper end plate and a lower end plate positioning groove disposed on the bottom surface of the lower end plate. The upper end plate positioning groove and the opposite lower end plate positioning groove together form a positioning groove body for accommodating the positioning member.

[0015] In some embodiments, the positioning component includes a first positioning component and a second positioning component, wherein the first positioning component and the second positioning component are respectively disposed on both sides of the conductive connection portion and located at the edge of the upper end plate.

[0016] In addition, the present invention also provides a fuel cell stack, the fuel cell stack comprising a plurality of stack units stacked vertically, the stack units being the aforementioned stack units.

[0017] In the fuel cell stack unit and fuel cell stack of the present invention, by adding conductive connection parts to the upper end plate and the lower end plate and adopting a serrated plug-in conductive mating structure, the conductive correlation between adjacent fuel cell stack units is ensured, the contact area between the upper end plate and the lower end plate is increased, the contact effect is improved, the contact resistance is reduced, and the conductivity is enhanced. At the same time, space is reserved for gas sealing between adjacent fuel cell stack units to prevent leakage of anode gas and cathode gas and avoid potential combustion risks. Each fuel cell stack unit can be quickly stacked, the operation is simple, the sealing and conductivity between each fuel cell stack unit are guaranteed, and the stable operation of the fuel cell stack is achieved.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of a fuel cell stack unit and a fuel cell stack according to a specific embodiment of the present invention;

[0021] Figure 2 for Figure 1 The exploded view of the partial structure shows the upper end plate, the adjacent lower end plate, the interface connection, the conductive connection, and the end plate sealing layer;

[0022] Figure 3 for Figure 2 The schematic diagrams of the partial structure from different perspectives show the upper end plate, the sawtooth part, the end plate sealing layer, the gas flow sealing channel and the upper end plate positioning groove.

[0023] Figure 4 for Figure 1 The top view of the upper end plate shown illustrates the upper end plate's air inlet port, air outlet port, serrated parts, and positioning groove.

[0024] Figure 5 for Figure 1 The diagram shown is a bottom view of the lower end plate, illustrating the air inlet, outlet, positioning groove, and serrated holes.

[0025] Figure 6 for Figure 1The diagram shows a top view of the end plate sealing layer.

[0026] Explanation of reference numerals in the attached figures:

[0027] 100 fuel cell stack units

[0028] 110 upper plate, 120 battery cell pack

[0029] 130 lower end plate

[0030] 200 Interface Connection Section

[0031] 210 Upper end plate interface connection part; 220 Lower end plate interface connection part

[0032] 300 Conductive Connection Part

[0033] 310 Upper end plate conductive connection part; 320 Lower end plate conductive connection part

[0034] 400 Flowing Gas Sealed Channel

[0035] 410 Inlet sealing channel 420 Outlet sealing channel

[0036] 510 Upper end plate positioning groove; 520 Lower end plate positioning groove

[0037] 1. Top surface of the upper end plate 2. Bottom surface of the lower end plate

[0038] 3. Serrated parts; 4. Serrated holes

[0039] 5. End plate sealing layer; 6. Upper end plate air inlet port.

[0040] 7. Upper end plate air outlet port; 8. Lower end plate air inlet port

[0041] 9. Lower end plate air outlet port; 10. Cover plate

[0042] L Endplate spacing H1 Sawtooth height

[0043] H2 Hole depth Detailed Implementation

[0044] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0046] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positions of components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0047] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Solid oxide fuel cells have broad application prospects due to their high chemical energy efficiency and environmental friendliness. For planar stationary oxide fuel cell stacks, they are generally composed of multiple stack units that are stacked on top of each other. The stack units have a box-like structure. When multiple stack units are stacked, the operation is cumbersome, and the interrelationship between the stack units is poor, which is not conducive to the stable operation of the fuel cell stack.

[0049] To address the problems in the prior art, this invention provides a novel fuel cell stack unit structure. See also... Figures 1 to 6 In a specific embodiment, the present invention provides a battery stack unit. The battery stack unit 100 includes a vertically stacked upper end plate 110, a battery cell group 120 and a lower end plate 130. The upper end plate top surface 1 of the upper end plate 110 and the lower end plate bottom surface 2 of the lower end plate 130 both include an interface connection part 200 and a conductive connection part 300.

[0050] The conductive connection portion 300 includes an upper end plate conductive connection portion 310 formed on the top surface 1 of the upper end plate and a lower end plate conductive connection portion 320 formed on the bottom surface 2 of the lower end plate. The upper end plate conductive connection portion 310 can form a plug-in conductive fit with the vertically adjacent lower end plate conductive connection portion 320.

[0051] In the fuel cell stack unit, the fuel cell stack unit 100 may include a vertically stacked upper end plate 110, a battery cell pack 120, and a lower end plate 130, such as... Figure 1 As shown. The conventional upper end plate 110 and lower end plate 130 are both plate-shaped structures. The upper end plate 110 and the adjacent lower end plate 130 are sealed together to prevent leakage of cathode gas and anode gas. Sealing between fuel cell units can be achieved using sealing elements or sealant. However, since the sealing structure has a certain thickness, it affects the conductivity between adjacent fuel cell units 100. Therefore, ensuring the conductivity between adjacent fuel cell units 100 is a crucial issue.

[0052] To address the shortcomings of existing designs where the sealing and conductivity of the upper end plate 110 and the lower end plate 130 are not fully compatible, this invention designs the adjacent structure of the stack unit 100 by adding a conductive connection portion 300 between the upper end plate 110 and the lower end plate 130. When stacked longitudinally, the top surface 1 of the upper end plate 110 can serve as the first adjacent end surface, and the bottom surface 2 of the lower end plate 130 can serve as the second adjacent end surface. The first adjacent end surface and the second adjacent end surface can have a conductive connection portion 300 to ensure the conductive connection between them. The upper end plate conductive connection portion 310 and the vertically adjacent lower end plate conductive connection portion 320 form a plug-in conductive fit. The upper end plate conductive connection portion 310 can be a boss structure, and the lower end plate conductive connection portion 320 can be a groove structure that accommodates the boss. The two are plugged into each other to form a direct contact connection, meaning that current can be transmitted between the upper end plate conductive connection portion 310 and the lower end plate conductive connection portion 320. It should be noted that both the upper end plate conductive connection portion 310 and the lower end plate conductive connection portion 320 are made of conductive materials. These conductive materials can be high-temperature resistant metallic conductive materials or composite polymer conductive materials; no specific limitation is made here.

[0053] In order to maximize conductivity while ensuring conductive connections, the conductive connection portion 300 is structurally designed between the stacked fuel cell units 100. (See [reference needed]). Figure 1 and Figure 2 One of the upper end plate conductive connection portion 310 and the lower end plate conductive connection portion 320 is a serrated member 3 protruding from the end plate surface, and the other is a serrated hole 4 recessed into the end plate surface. For example, the serrated member 3 is located on the upper end plate conductive connection portion 310, and the serrated hole 4 is located on the lower end plate conductive connection portion 320; or, the serrated hole 4 is located on the upper end plate conductive connection portion 310, and the serrated member 3 is located on the lower end plate conductive connection portion 320. Multiple serrations can be formed on the serrated member 3 at intervals, and multiple serrations can be formed in the serrated hole 4 at intervals. The two serrated structures interlock with each other. Through this serrated electrical connection structure, the contact area between the upper end plate 110 and the lower end plate 130 can be increased, the contact effect can be improved, and the contact resistance can be reduced, enhancing the conductivity. At the same time, the serrated plug-in structure can further improve the positioning effect between adjacent stack units 100 and improve the stacking efficiency between each stack unit 100.

[0054] Optional, such as Figure 2 As shown, the serration height of the serrated part 3 is H1, and the hole depth of the serrated hole 4 is H2. To ensure a gap exists between the upper end plate 110 and the adjacent lower end plate 130 when the serrated part 3 and the serrated hole 4 mesh, the serration height of the serrated part 3 is greater than the hole depth of the serrated hole 4, resulting in an end plate spacing L between the vertically adjacent upper end plate 110 and lower end plate 130. Figure 1 As shown. This arrangement ensures direct contact between the upper end plate 110 and the lower end plate 130, i.e., electrical conductivity, while also reserving a certain space for gas-conducting sealing between adjacent fuel cell stack units 100. The structure is simple and highly operable.

[0055] While ensuring conductivity, the sealing structure is further designed. In one embodiment, such as... Figure 1 and Figure 2 As shown, the interface connection portion 200 may include an upper end plate interface connection portion 210 formed on the top surface 1 of the upper end plate and a lower end plate interface connection portion 220 formed on the bottom surface 2 of the lower end plate. The end plate spacing L is formed between the upper end plate interface connection portion 210 and the opposite lower end plate interface connection portion 220. It can be understood that both the top surface 1 of the upper end plate and the bottom surface 2 of the lower end plate are non-planar. The spacing formed between the upper end plate interface connection portion 210 and the opposite lower end plate interface connection portion 220 is the end plate spacing L. The end plate spacing L can be used to fill sealing material so that the gas between the fuel cell units 100 does not leak outward.

[0056] Because the reaction temperature of fuel cell stacks is very high, reaching 600 to 800°C, the filling sealing material within the endplate spacing L is designed to ensure good sealing performance, as shown in Figure 2. Figure 3 and Figure 5 As shown, in one embodiment, the end plate spacing L can be filled with an end plate sealing layer 5, so that a gas sealing channel 400 is formed between the vertically adjacent upper end plate interface connection portion 210 and the lower end plate interface connection portion 220, which is sealed to the outside. The end plate sealing layer 5 can be made of a high-temperature resistant material, such as glass or ceramic, etc., without specific limitations. Figure 6 As shown, the end plate sealing layer 5 can be a plate-shaped structure, which is simple in structure and easy to operate. Its lower end face is sealed to the upper end plate interface connection part 210, and its upper end face is sealed to the lower end plate interface connection part 220. It can be understood that the shape and structure of the end plate sealing layer 5 are adapted to the shape and spacing of the end plate spacing L. By filling the end plate sealing layer 5, leakage of anode gas and cathode gas is prevented, avoiding potential combustion risks. In addition, in order to ensure the transfer of anode gas and cathode gas between the fuel cell unit 100, a gas flow sealing channel 400 can be formed on the end plate sealing layer 5. It can be understood that a through hole is formed on the end plate sealing layer 5, so that the end plate sealing layer 5 is a structure that is sealed on the outside and allows internal flow.

[0057] Since the fuel cell stack contains anode fuel gas and cathode air, the anode fuel gas between each stack unit 100 can be transferred using a through-type gas passage structure, and the cathode air can be transferred using a through-type gas passage structure or an open gas passage structure. Therefore, the gas flow sealing channel 400 can include an inlet sealing channel 410 for guiding the intake gas, i.e., a flow channel for fuel gas and air, and an outlet sealing channel 420 for guiding the exhaust gas, i.e., a flow channel for anode and cathode exhaust gas.

[0058] The upper end plate interface connection portion 210 is provided with an upper end plate inlet port 6 for forming a gas inlet of the fuel cell stack unit 100 and an upper end plate outlet port 7 for forming a gas outlet of the fuel cell stack unit 100. The lower end plate interface connection portion 220 is provided with a lower end plate inlet port 8 for forming a gas inlet of the fuel cell stack unit 100 and a lower end plate outlet port 9 for forming a gas outlet of the fuel cell stack unit 100. This forms an inlet sealing channel 410 between the upper end plate inlet port 6 and the corresponding lower end plate inlet port 8, and an outlet sealing channel 420 between the upper end plate outlet port 7 and the corresponding lower end plate outlet port 9. This can be understood as... Figure 1 , Figure 4 and Figure 5 As shown, there are two air inlet ports 6 on the upper end plate and two air inlet ports 8 on the opposite lower end plate. A gas intake pipe is formed between one of the upper end plate air inlet ports 6 and the opposite lower end plate air inlet port 8, and an air intake pipe is formed between the other two. The gas intake pipe and the air intake pipe are enclosed within the inlet sealing channel 410 to achieve a seal for the intake pipes. There are two air outlet ports 7 on the upper end plate and two air outlet ports 9 on the opposite lower end plate. An anode exhaust pipe is formed between one of the upper end plate air outlet ports 7 and the opposite lower end plate air outlet port 9, and a cathode exhaust pipe is formed between the other two. The anode exhaust pipe and the cathode exhaust pipe are enclosed within the outlet sealing channel 420 to achieve a seal for the exhaust pipes. Further, as... Figure 2 As shown, the inlet sealing channel 410 and the outlet sealing channel 420 can be respectively located on both sides of the conductive connection part 300. This prevents gas leakage and ensures stable flow in each gas path.

[0059] To facilitate the stacking of multiple fuel cell stack units 100 and ensure precise alignment of the gas ports of the lower end plate interface connection 220, this embodiment further designs the positioning structure of the fuel cell stack unit 100, such as... Figure 3 and Figure 4As shown, a positioning component for fixing the adjacent fuel cell unit 100 is also included between the top surface 1 of the upper end plate and the bottom surface 2 of the lower end plate. The positioning component may include an upper end plate positioning groove 510 disposed on the top surface 1 of the upper end plate and a lower end plate positioning groove 520 disposed on the bottom surface 2 of the lower end plate. The upper end plate positioning groove 510 and the opposite lower end plate positioning groove 520 together form a positioning groove for accommodating the positioning component. The positioning component can be understood as consisting of an upper end plate positioning groove 510, a lower end plate positioning groove 520, and a positioning element. The positioning element is housed within the upper end plate positioning groove 510. When stacked, the lower end plate 130 of the adjacent fuel cell stack unit 100 is stacked on the bottom upper end plate 110, and the lower end plate positioning groove 520 covers the positioning element. This can define the approximate position of the adjacent fuel cell stack unit 100. At this time, the serrated structure of the conductive connection part 300 performs secondary positioning of the fuel cell stack unit 100, making small-range fine adjustments to ensure the interlocking area of ​​the serrated structure. Through the primary positioning of the positioning component and the secondary positioning of the conductive connection part 300, the stack formed by the fuel cell stack unit 100 is made into a longitudinal box structure, ensuring precise alignment between the gas ports of the lower end plate interface connection part 220 and improving the effectiveness of gas distribution.

[0060] Furthermore, in order to ensure the positioning effect of the positioning component, such as Figure 3 As shown, the positioning component may include a first positioning component and a second positioning component. The first positioning component and the second positioning component are respectively disposed on both sides of the conductive connection part 300 and located at the edge of the plate surface of the upper end plate 110. It can be understood that the first positioning component and the second positioning component are distributed and located at the outer frame of the plate surface of the upper end plate 110, thereby improving its positioning effect and further ensuring the accurate alignment of each gas port.

[0061] In addition, the present invention also provides a fuel cell stack, which includes a plurality of stack units 100 stacked vertically. The stack unit 100 is the stack unit mentioned above. The fuel cell stack may also include a cathode gas pipe and an anode gas pipe (not shown in the figure). The top of the lower stack unit 100 is connected to the bottom of the upper stack unit 100. The anode gas pipe and the cathode gas pipe run from the bottom to the top of the stack unit 100. Each stack unit 100 may not require a separate gas supply device. The gas inlet pipe in the cathode gas pipe and the anode gas pipe can be wrapped in the inlet sealing channel 410, and the gas outlet pipe can be wrapped in the outlet sealing channel 420. The stack tower with this through-type gas pipe is simpler than the stack tower with a non-through-type gas pipe.

[0062] Specifically, such as Figure 1As shown, stacking multiple fuel cell stack units 100 may include the following steps: A sealing layer 5 is placed at the upper end plate interface connection 210 of the upper end plate 110 of the bottom fuel cell stack unit 100; a positioning member is placed in the positioning groove 510 of the upper end plate of the bottom fuel cell stack unit 100, and the positioning member is kept vertical; when stacking adjacent fuel cell stack units 100 with the bottom fuel cell stack unit 100, the positioning member is inserted into the positioning groove 520 of the lower end plate, at which point the adjacent fuel cell stack unit 100 is placed on top of the bottom fuel cell stack unit 100; then, the position of the adjacent fuel cell stack unit 100 is finely adjusted so that the serrated part 3 of the bottom fuel cell stack unit 100 is inserted into the serrated hole 4 of the adjacent fuel cell stack unit 100, and the two are tightly closed and interlocked, ensuring that the positive electrode of the bottom fuel cell stack unit 100 is connected to the negative electrode of the adjacent fuel cell stack unit 100, thus completing the connection of two fuel cell stack units. The stack units 100 are connected in series. At the same time, the end plate sealing layer 5 is tightly attached to the two stack units 100 to ensure that when the two stacks are connected in series, the upper end plate air inlet port 6 and the lower end plate air inlet port 8, and the upper end plate air outlet port 7 and the lower end plate air outlet port 9 correspond one-to-one and are well sealed to the outside. The above steps can be repeated to continue stacking the stack units. Finally, a cover plate 10 is set on the upper end plate 110 of the top stack unit 100. The cover plate 10 has no gas channel and is located at the top of the entire stack tower. It radially blocks the upper end plate air inlet port 6 and the lower end plate air inlet port 8 to prevent fuel gas and air from leaking out. There is no conductive adhesive between adjacent stack units 100 during the entire stacking process, which avoids the problem of difficult disassembly of stack units due to the high temperature drying of conductive adhesive. At the same time, the residue of conductive adhesive is eliminated, so that the stack units can be reused.

[0063] It should be noted that the other components and functions of the fuel cell stack unit and fuel cell stack in the embodiments of the present invention are known to those skilled in the art, and will not be described in detail here in order to reduce redundancy.

[0064] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, such as changes in the shape, thickness and material of the end plate sealing layer. These simple modifications are all within the protection scope of the present invention.

[0065] It should also be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Where there is no contradiction, they can be combined in any suitable manner; to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0066] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A stack unit, characterized by The electric stack unit (100) comprises vertically stacked upper end plate (110), battery sheet group (120) and lower end plate (130), the upper end plate top surface (1) of the upper end plate (110) and the lower end plate bottom surface (2) of the lower end plate (130) both comprise interface connection part (200) and conductive connection part (300); Wherein, the conductive connection part (300) comprises upper end plate conductive connection part (310) formed on the upper end plate top surface (1) and lower end plate conductive connection part (320) formed on the lower end plate bottom surface (2), the upper end plate conductive connection part (310) can form plug-in conductive cooperation with vertically adjacent lower end plate conductive connection part (320); One of the upper end plate conductive connection part (310) and the lower end plate conductive connection part (320) is a sawtooth piece (3) protruding from the end plate surface, and the other is a sawtooth hole (4) recessed in the end plate surface, the sawtooth height of the sawtooth piece (3) is greater than the hole depth of the sawtooth hole (4), so that the end plate spacing (L) is formed between the vertically adjacent upper end plate (110) and the lower end plate (130); the end plate spacing (L) is filled with an end plate sealing layer (5), the interface connection part (200) comprises upper end plate interface connection part (210) formed on the upper end plate top surface (1) and lower end plate interface connection part (220) formed on the lower end plate bottom surface (2), the end plate spacing (L) is formed between the upper end plate interface connection part (210) and the opposite lower end plate interface connection part (220), and the upper end plate interface connection part (210) and the lower end plate interface connection part (220) vertically adjacent to each other form a flow gas sealing channel (400) which is sealed to the outside.

2. The stack unit of claim 1, wherein, The flow gas sealing channel (400) comprises an inlet sealing channel (410) for conducting inlet gas and an outlet sealing channel (420) for conducting outlet gas; Wherein, the upper end plate interface connection part (210) is provided with an upper end plate gas inlet port (6) for forming a gas inlet of the electric stack unit (100) and an upper end plate gas outlet port (7) for forming a gas outlet of the electric stack unit (100), and the lower end plate interface connection part (220) is provided with a lower end plate gas inlet port (8) for forming a gas inlet of the electric stack unit (100) and a lower end plate gas outlet port (9) for forming a gas outlet of the electric stack unit (100), so that the upper end plate gas inlet port (6) and the opposite lower end plate gas inlet port (8) form the inlet sealing channel (410), and the upper end plate gas outlet port (7) and the opposite lower end plate gas outlet port (9) form the outlet sealing channel (420).

3. The stack unit of claim 2, wherein, The inlet sealing channel (410) and the outlet sealing channel (420) are separately arranged on both sides of the conductive connection part (300).

4. The stack unit of claim 1, wherein, The end plate sealing layer (5) is a high-temperature resistant material.

5. The stack unit according to any one of claims 1 to 4, characterized in that The upper end plate top surface (1) and the lower end plate bottom surface (2) further comprise a positioning assembly for fixing the adjacent stack unit (100), the positioning assembly comprises an upper end plate positioning groove (510) arranged on the upper end plate top surface (1) and a lower end plate positioning groove (520) arranged on the lower end plate bottom surface (2), the upper end plate positioning groove (510) and the opposite lower end plate positioning groove (520) jointly form a positioning groove body for accommodating a positioning member.

6. The stack unit of claim 5, wherein, The positioning assembly comprises a first positioning assembly and a second positioning assembly, the first positioning assembly and the second positioning assembly are arranged on both sides of the conductive connection part (300) and located at the edge of the plate surface of the upper end plate (110).

7. A fuel cell stack characterised in that The fuel cell stack comprises a plurality of vertically stacked stack units (100), and the stack unit (100) is the stack unit according to any one of claims 1-6.

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