Battery stack pressurization positioning device and battery stack pressurization positioning method

Abstract

The application relates to the technical field of battery assembly testing, and discloses a battery stack pressurizing positioning device and a battery stack pressurizing positioning method. The device comprises a pressure supply unit and an equalizing unit. The equalizing unit comprises a base, a plurality of through holes are arranged on the pressurizing end face of the base, pistons are filled in the holes, and the pistons are arranged to be capable of moving in the holes and sealing the through holes. The pressure supply unit comprises an upper cavity and a lower cavity in communication with the upper cavity, the base is detachably fixed in the lower cavity, and the upper and lower cavities and the equalizing unit jointly form a closed gas chamber. The upper cavity is connected with a gas pump through an inlet and outlet pipeline, and the gas pump is arranged to be capable of exhausting or charging the gas chamber to control the position of the pistons in the through holes. The device can uniformly apply pressure and realize variable pressure adjustment, simultaneously clamps and positions the battery stack, can guarantee the position stability and uniform stress of the battery stack during temperature rising and falling and testing, is suitable for various forms of battery stacks and battery stack combinations, and is simple to operate and high in flexibility.

Description

Technical Field

[0001] This invention relates to the field of battery assembly and testing technology, and more specifically to a battery stack pressurization and positioning device and a battery stack pressurization and positioning method. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are all-solid-state chemical power generation devices that directly convert the chemical energy in fuel and oxides into electrical energy. A single SOFC cell mainly consists of three layers: an anode, an electrolyte, and a cathode. The anode is where the fuel gas is oxidized and electrons are generated. The electrolyte's function is to conduct oxygen ions from the cathode to the anode, and its dense structure isolates the anode and cathode gases. The cathode is where oxygen molecules consume electrons to become oxygen ions. Electrons generated in the anode are transported along the external circuit to the cathode to form an electric current.

[0003] Planar SOFCs possess advantages such as simple structure, high power density, and good electrical performance, making them the mainstream and hot topic in SOFC research both domestically and internationally. Planar SOFC stacks are typically composed of multiple individual cells stacked together. Appropriate loads need to be introduced to apply pressure to the individual cells, seals, connectors, and other components within the stack to ensure tight contact between the cell interfaces. Furthermore, when using compaction sealing materials for stack sealing, additional pressure is required to ensure the overall stack's airtightness. Therefore, the difficulty of sealing is one of the main challenges restricting the development of planar SOFCs. Since solid oxide fuel cells typically operate at 600–800°C, with high operating temperatures and repeated thermal cycling, the load applied to the stack needs to be uniform and stable to ensure normal and efficient operation. Moreover, pressure regulation is required during operation to maintain good airtightness of the stack at different temperatures.

[0004] Current technologies for pressurizing SOFC battery stacks typically employ rigid pressurization. Traditional rigid pressurization cannot effectively guarantee the uniformity of stress loading, thus affecting the sealing performance of the battery stack. Due to the shortcomings of existing technologies, there is an urgent need for a novel battery stack pressurization and positioning device and method. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of insufficient fuel cell stack sealing caused by uneven pressure application during pressurization in existing solid oxide fuel cell stacks. This invention provides a fuel cell stack pressurization and positioning device that applies uniform pressure and allows for pressure regulation, ensuring pressure stability during temperature rise, fall, and testing. Simultaneously, this device can position the fuel cell stack, preventing displacement during assembly and operation. This fuel cell stack pressurization and positioning device can be used for pressurizing and positioning various types of fuel cell stacks and stack combinations, offering wide applicability, ease of operation, and high flexibility.

[0006] To achieve the above objectives, the present invention provides a battery stack pressurization and positioning device, which includes a pressure supply unit and a pressure equalization unit. The pressure supply unit is configured to apply pressure to the pressure equalization unit and the pressure equalization unit transmits the pressure and applies it evenly to the battery stack to be pressurized and positioned.

[0007] The pressure equalization unit includes a base and a base cover plate. The pressure end face of the base and the base cover plate is provided with multiple through holes. Each through hole is filled with a piston, which is configured to move within the through hole and seal the through hole.

[0008] The pressure supply unit includes an upper cavity and a lower cavity communicating with the upper cavity. The base is detachably fixed to the lower cavity, and the upper cavity, the lower cavity, and the pressure equalization unit together form a closed gas chamber.

[0009] The upper chamber is connected to an air pump via inlet and outlet pipes. The air pump is configured to evacuate or inflate the gas chamber to control the position of the piston within the through hole.

[0010] Preferably, the inlet and outlet pipes are connected to the air pump via valves, which are used to control the air pump to open or close.

[0011] Preferably, bolt holes are provided on the side wall of the base, and the base is fixed to the lower cavity by means of a connector and bolts.

[0012] Preferably, the inner wall of the lower cavity is provided with a positioning boss for positioning the base in the lower cavity.

[0013] Preferably, the pressure supply unit further includes pressure sensors installed on the inlet and outlet pipes, the pressure sensors being used to measure the gas pressure inside the gas chamber; wherein,

[0014] When the pressure sensor outputs a negative value, the piston is at the top of the through hole, the valve is closed, and the air pump stops pumping air.

[0015] When the valve is opened, the air pump fills the gas chamber with air. When the pressure sensor outputs the required operating pressure, the piston moves downward in the through hole to the upper surface of the battery stack and applies uniform pressure to the battery stack.

[0016] Preferably, the piston located on the side wall of the battery stack is attached to the side wall of the battery stack and clamps and positions the battery stack.

[0017] Preferably, the battery stack pressurization and positioning device further includes an upper support and a lower support, which are detachably mounted on the upper cavity. Furthermore, the upper support and the lower support are configured to clamp and fix the position of the upper cavity from the outside and inside of the hot box, respectively, when the upper cavity is mounted on the hot box.

[0018] Preferably, the outer wall of the upper cavity is formed with multiple layers of threads to adjust the installation position of the upper and lower supports according to the height of the battery stack, so as to ensure that the lower end of the piston is in close contact with the upper surface of the battery stack.

[0019] Preferably, the piston includes a piston head and a piston rod connected to the end of the piston head. The outer surface of the piston head has multiple annular grooves for sealing with the labyrinthine gap of the through hole.

[0020] Preferably, the through hole includes an upper through hole, a middle through hole, and a lower through hole; wherein, the upper through hole is connected to the gas chamber, the middle through hole is used to accommodate the piston head, and the lower through hole cooperates with the piston rod to seal the through hole.

[0021] A second aspect of the present invention provides a method for pressurizing and positioning a battery stack using the aforementioned battery stack pressurizing and positioning device, the method comprising:

[0022] First, select a base, base cover plate and piston that match the size of the battery stack. Fix the base and the lower cavity with the connector. Open the valves of the inlet and outlet pipes. Use the air pump to draw the gas into the negative pressure in the gas chamber. After the piston is at the top of the through hole in the base, close the valves of the inlet and outlet pipes.

[0023] Then, install the upper and lower supports in the upper cavity, place the entire support into the hot box where the fuel cell stack is running, and adjust the position of the upper and lower supports according to the height of the fuel cell stack. That is, install the upper and lower supports along the threads on the outer wall of the upper cavity to the appropriate position so that the lower end of the piston contacts the upper surface of the fuel cell stack. At the same time, the upper and lower supports are respectively in close contact with the inner and outer walls of the top shell of the hot box. At this time, the pressure positioning device is fixed to the hot box.

[0024] When pressurization of the battery stack is required, the valves of the inlet and outlet pipes are opened, and the gas pump is used to fill the gas chamber to the required pressure. The pressure in the gas chamber pushes the piston at the top of the battery stack to press the battery stack, and the piston on the side wall of the battery stack clamps and positions the battery stack. Furthermore, during operation, the pressure change in the gas chamber is monitored in real time by a pressure sensor, and the pressure is adjusted by the gas pump according to the operating conditions.

[0025] The above technical solution connects the pressure supply unit and the pressure equalization unit. Pressure is applied by the pressure supply unit and transmitted to the pressure equalization unit, which then applies the pressure evenly to the battery stack to be pressurized and positioned. This allows for uniform pressurization of the top of the battery stack and enables pressure regulation, ensuring pressure stability during temperature rise, fall, and testing. Simultaneously, the pressure equalization unit can position the battery stack, preventing displacement. Furthermore, this battery stack pressurization and positioning device is applicable to various types of battery stacks and battery stack combinations, offering wide applicability, ease of operation, and high flexibility. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overhead view of a battery stack pressurization and positioning device provided by the present invention;

[0027] Figure 2 This is a top-view structural diagram of a battery stack pressurization and positioning device provided by the present invention;

[0028] Figure 3 This is a cross-sectional view of a battery stack pressurization and positioning device provided according to the present invention;

[0029] Figure 4 This is a cross-sectional view of the base in a battery stack pressurization and positioning device provided by the present invention;

[0030] Figure 5 This is a partial structural cross-sectional view of a battery stack pressurization and positioning device provided according to the present invention;

[0031] Figure 6 This is a schematic diagram of the piston structure in a battery stack pressurization and positioning device according to the present invention;

[0032] Figure 7 This is a cross-sectional view of Embodiment 1 provided according to the present invention;

[0033] Figure 8 This is a partial cross-sectional view of Embodiment 2 provided by the present invention;

[0034] Figure 9 This is a partial cross-sectional view of Embodiment 3 provided according to the present invention.

[0035] Explanation of reference numerals in the attached figures

[0036] 1-Upper cavity 2-Lower cavity

[0037] 21-Positioning boss

[0038] 3-Pressure sensor 4-Inlet / outlet pipes

[0039] 5-Valve 6-Upper Support

[0040] 7-Lower support 8-Base

[0041] 81-Through Hole 811-Top Through Hole

[0042] 812 - Center through hole; 813 - Bottom through hole

[0043] 82- Bolt hole 83- Base cover plate

[0044] 9-Piston 91-Piston Head

[0045] 92-Piston rod 10-Connector

[0046] 101-Bolt 11-Gas Chamber Detailed Implementation

[0047] 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.

[0048] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "inner," and "outer" in the terminology represent the orientation of the term in its normal use or are common terms understood by those skilled in the art, and should not be regarded as limitations on the term.

[0049] The present invention provides a battery stack pressurization and positioning device, which includes a pressure supply unit and a pressure equalization unit. The pressure supply unit is configured to apply pressure to the pressure equalization unit and the pressure equalization unit transmits the pressure and applies it evenly to the battery stack to be pressurized and positioned.

[0050] See Figure 1 and Figure 2 The pressure equalization unit includes a base 8 and a base cover plate 83. The pressure end face of the base 8 and the base cover plate 83 is provided with a plurality of through holes 81. Each through hole 81 is filled with a piston 9. The base cover plate 83 covers the base 8 to restrict the piston 9 to move only in the through hole. The piston 9 is configured to be able to move within the through hole 81 and seal the through hole 81.

[0051] The pressure supply unit includes an upper cavity 1 and a lower cavity 2 communicating with the upper cavity 1. A base 8 is detachably fixed to the lower cavity 2. The upper cavity 1, lower cavity 2, and pressure equalization unit together form a closed gas chamber 11 (e.g., ...). Figure 3 (as shown);

[0052] The upper cavity 1 is connected to the air pump through the inlet and outlet pipes 4. The air pump is configured to evacuate or inflate the gas chamber 11 to control the position of the piston 9 in the through hole 81.

[0053] Specifically, such as Figure 4As shown, the base 8 can be a cuboid with multiple through holes, and the dimensions of the base cover plate 83 are consistent with the upper surface of the base 8. A positioning boss 21 is provided on the inner wall of the lower cavity to position the base within the lower cavity. The outer wall of the base 8 is tightly fitted to the inner surface of the lower cavity 2. Bolt holes 82 are provided on the side wall of the base 8, which is fixed to the lower cavity 2 by the cooperation of the connector 10 and bolts 101. Specifically, the connector 10 between the base 8 and the lower cavity 2 can be a square protective plate with an L-shaped cross-section. The lower horizontal edge of the protective plate abuts against the lower surface of the base 8, and the upper vertical edge of the protective plate fits against the outer surface of the lower cavity 2. A threaded through hole is provided on the vertical edge of the protective plate, which is fastened to the lower cavity 2 by the fastening bolts 101. After the base 8 and the lower cavity 2 are fastened by the fastening bolts 101, the contact surfaces of the base 2 and the lower cavity 2 are tightly fitted and can ensure sufficient sealing.

[0054] Specifically, such as Figure 4 and Figure 5 As shown, the through hole 81 consists of three parts of different shapes. The upper through hole 811 is opened in the base cover plate 83, and the middle through hole 812 and the lower through hole 813 are opened in the base 8. The positions of the upper and lower through holes are matched accordingly. The upper through hole 811 and the middle through hole 812 are cylindrical with different diameters, while the lower through hole 813 is square. A piston 9 is placed inside the through hole 81. The piston 9 matches the size of the middle through hole 812 and the lower through hole 813, thereby sealing the lower end of the through hole 81. The upper through hole 811 communicates with the gas chamber 11. As the pressure in the gas chamber 11 changes, the piston 9 can move up and down within the through hole 81 of the base 8.

[0055] To improve the sealing performance of piston 9 during movement, preferably, piston 9 has a cylindrical piston head with multiple annular grooves on its outer surface for labyrinthine gap sealing with through hole 81. Specifically, as shown... Figure 6 As shown, the piston 9 includes a piston head 91 and a piston rod 92. The piston head 91 is a cylinder and the piston rod 92 is a square prism. Multiple annular grooves are opened on the side wall of the cylindrical piston head to form a labyrinth-type sealing structure with the middle of the through hole. This can greatly improve the sealing performance, so that the gas pressure adjustment in the gas chamber 11 can drive the piston mechanical movement more efficiently.

[0056] In the process of using the battery stack pressurization and positioning device, in order to facilitate the monitoring and control of the gas pressure in the gas chamber 11 and to achieve precise pressurization and positioning for different battery stacks, preferably, the pressure supply unit also includes a pressure sensor 3 installed on the inlet and outlet pipes 4. The pressure sensor 3 is used to measure the gas pressure in the gas chamber 11; and the inlet and outlet pipes 4 are connected to the air pump through valves 5, which are used to control the air pump to open or close. With the above structure, when the output of the pressure sensor 3 is negative, the piston 9 is at the uppermost end of the through hole 81, the valve 5 is closed, and the air pump stops pumping air.

[0057] When valve 5 is opened, the air pump fills the gas chamber 11 with air. When the pressure sensor 3 outputs the operating pressure required for the battery stack, the piston 9 moves downward in the through hole 81 to the upper surface of the battery stack and applies uniform pressure to the battery stack.

[0058] Furthermore, this invention allows for the adjustment of the base 8, base cover plate 83, and piston 9 according to the required pressurization configuration of the battery stack, thereby clamping and positioning the battery stack. A portion of the pistons in the equalizing unit serves as positioning posts for the battery stack. This portion of the pistons refers to piston 9 that does not directly apply pressure to the battery stack and whose sidewalls are in contact with the stack's sidewalls. When the gas chamber 11 is pressurized, this portion of the pistons moves downwards to the sidewalls of the battery stack, clamping and positioning the stack from the sidewalls. Simultaneously, the specific positions and shapes of the base 8 and piston 9 can be adjusted according to the actual shape of the battery stack, enabling this portion of the pistons to position various battery stacks and combinations, further improving flexibility and significantly expanding its applicability.

[0059] To facilitate the installation and positioning of the battery stack pressurization and positioning device during use, the battery stack pressurization and positioning device preferably further includes an upper support 6 and a lower support 7. The upper support 6 and the lower support 7 are detachably installed on the upper cavity 1, and are configured such that when the upper cavity 1 is installed on the hot box, the upper support 6 and the lower support 7 can clamp and fix the position of the upper cavity 1 from the outside and inside of the hot box, respectively.

[0060] Furthermore, the outer wall of the upper cavity 1 is formed with multiple layers of threads to adjust the installation positions of the upper support 6 and the lower support 7 according to the height of the battery stack, so as to ensure that the lower end of the piston 9 is in close contact with the upper surface of the battery stack.

[0061] Furthermore, the upper support 6 and the lower support 7 are arranged in parallel.

[0062] When using this invention, as Figure 7As shown, firstly, select a base 8, base cover plate 83, and piston 9 that match the size of the battery stack. After inserting piston 9 into through hole 81, cover base 8 with base cover plate 83. Fix base 8 and lower cavity 2 with connector 10. Open valve 5 of inlet / outlet pipe 4 and use air pump to create negative pressure in gas chamber 11, so that piston 9 is at the uppermost end of base through hole 81. Then close valve 5 of inlet / outlet pipe 4. Install upper bracket 6 and lower bracket 7 on the outer wall of upper cavity 1. Place the entire bracket into the hot box where the battery stack operates. Adjust the position of upper bracket 6 and lower bracket 7 according to the height of the battery stack, that is, thread upper bracket 6 and lower bracket 7 along the outer wall of upper cavity 1 to a suitable position, so that the lower end of piston 9 contacts the upper surface of battery stack. At the same time, upper bracket 6 and lower bracket 7 are tightly attached to the inner and outer walls of the top shell of hot box, respectively. Pressurization positioning device is then fixed to hot box. When pressurization of the battery stack is required, valve 5 of the inlet / outlet pipe 4 is opened, and air is pumped into the gas chamber 11 to the required pressure. The pressure inside the gas chamber 11 pushes the piston at the top of the battery stack to pressurize it, while pistons on the side walls of the battery stack position it. Furthermore, during operation, pressure changes within the gas chamber 11 can be monitored at any time via pressure sensor 3, and the pressure can be adjusted by the air pump according to operating conditions.

[0063] It can be seen that after the gas chamber 11 is pressurized, the pressure in the gas chamber 11 is uniform, and the pressure applied to each piston 9 is also the same. Under the push of the piston 9, the battery stack is pressurized evenly, which can achieve uniform force on the top of the battery stack.

[0064] Secondly, the pressure sensor 3 and the inlet and outlet pipes 4 are far away from the high-temperature area where the battery stack is located, so the pressure can be flexibly adjusted according to the test conditions during the battery stack test. The pressure sensor can accurately and in real time display and record the pressure on the battery stack, and effectively monitor the clamping force of the battery stack.

[0065] Secondly, the movable piston 9 pressurizes the battery stack, and the position of the piston 9 can be adjusted according to the changes in the thermal expansion performance of the battery stack during the heating and cooling process, so as to ensure the stability of the applied pressure load, avoid rigid contact as when using steel plates for pressurization, and reduce damage to the battery stack caused by thermal expansion during high-temperature operation.

[0066] Meanwhile, the base 8, base cover 83 and piston 9 in the equalizing unit can be replaced according to the battery stack structure, which can realize the adaptation to battery stacks of different types and specifications, and can also meet the simultaneous pressurization of multiple battery stacks.

[0067] Furthermore, some pistons are used to position the battery stack. By selecting a base 8 with a suitable opening position and an appropriate number of pistons 9, the side wall of the battery stack is positioned and clamped to ensure that the battery stack is fixed and accurate, prevent the battery stack from shaking and tipping over during operation, and ensure that the battery stack is stable and subjected to uniform force.

[0068] like Figure 7 As shown, in Example 1, the battery stack pressurization and positioning device is used to pressurize and position a rectangular single battery stack A:

[0069] Based on the shape of the rectangular battery stack A, select a matching base 8 and piston 9. After assembling the piston 9 in the base 8, cover it with the base cover plate 83, and place the base 8 into the lower cavity 2. Secure the base 8 and the lower cavity 2 with bolts 101 using the connector 10. Connect the inlet and outlet pipes 4 to the air pump, open the valve 5, and start the air pump to evacuate the gas chamber 11 until the pressure sensor 3 outputs a negative value, so that the piston 9 is at the uppermost position of the base through hole 81. Then close the valve 5. After the rectangular battery stack is placed in the appropriate position in the hot box, insert the lower support 7 and the upper support 6 into the threaded area of ​​the outer wall of the upper cavity in sequence. Place the pressurization and positioning device at the top of the hot box, with the lower support 7 and the upper support 6 located on the inner and outer sides of the top outer shell of the hot box. Adjust the position of the upper support according to the height of the battery stack, ensuring that the lower end of piston 9 is in close contact with the upper surface of the battery stack. After determining the position, fix the upper support 6 along the thread of the upper cavity 1 to the outer wall of the top shell of the hot box, and simultaneously fix the lower support 6 along the thread of the upper cavity 1 to the inner wall of the top shell of the hot box. When the battery stack is pressurized during operation, open the valve 5 of the inlet and outlet pipes 4 to fill the gas chamber 11 with gas until the pressure sensor 3 outputs the required operating pressure. The pressure in the gas chamber 11 pushes piston 9 downward, and the piston in contact with the upper surface of the battery stack applies uniform pressure to the battery stack. At the same time, the piston that positions the battery stack adheres to the side wall of the battery stack under pressure. During the heating, cooling, or testing of battery stack A, the pressure sensor 3 can monitor the pressure changes in the gas chamber 11 in real time, and the pressure can be adjusted by the air pump according to the actual pressure conditions required for the operation of the battery stack. After the battery stack A test is completed, open valve 5 to slowly depressurize to atmospheric pressure, then turn on the air pump to evacuate the gas chamber 11 until the pressure sensor 3 outputs a negative value, so that the piston 9 is at the uppermost end of the base through hole 81. Then close valve 5. Rotate the upper bracket 6 and the lower bracket 7 along the threads on the outer wall of the upper cavity 1 to remove the pressurization and positioning device from the top of the hot box.

[0070] like Figure 8As shown, in Embodiment 2, the battery stack pressurization and positioning device is used to simultaneously pressurize and position four identical battery stacks B / C / D / E, where battery stack D / E is obscured by B / C. Bases 8 and pistons 9 are selected to match the size and position of battery stacks B / C / D / E. After the pistons 9 are assembled in the bases 8, the base cover plate 83 is placed over them, and the bases 8 and lower cavity 2 are fixed together by the connector 10. The remaining assembly process and operation method are the same as in Embodiment 1. In this embodiment, since the pressure transmitted from the pressure supply unit to each piston 9 in the pressure equalization unit is the same, the pressure applied to the surface of each battery stack is the same, thus ensuring uniform force distribution across each battery stack.

[0071] like Figure 9 As shown, in Example 3, the battery stack pressurization and positioning device is used to simultaneously pressurize and position two battery stacks F / G of different sizes. A matching base 8 and piston 9 are selected based on the size of the battery stacks F / G. The piston position and piston rod length can be adjusted according to the size and height of different battery stacks to ensure that each stack can be pressurized and clamped for positioning. After the piston 9 is assembled in the base 8, the base cover plate 83 is covered, and then the base 8 and the lower cavity 2 are fixed together by the connector 10. The remaining assembly process and operation method are the same as in Example 1. In this example, the size and length of the piston rod are matched to the battery stacks, enabling clamping and positioning of different battery stacks. Simultaneously, because the pressure transmitted from the pressure supply unit to each piston 9 in the pressure equalization unit is the same, uniform force is ensured on each battery stack.

[0072] 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 thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A battery stack pressurization and positioning device, characterized in that, The battery stack pressurization and positioning device includes a pressure supply unit and a pressure equalization unit. The pressure supply unit is configured to apply pressure to the pressure equalization unit, and the pressure equalization unit is configured to transmit and uniformly apply the pressure from the pressure supply unit to the battery stack to be pressurized and positioned. The pressure equalization unit includes a base (8) and a base cover plate (83). The base (8) and the base cover plate (83) are provided with a plurality of through holes (81). Each through hole (81) is filled with a piston (9). The piston (9) is configured to be able to move within the through hole (81) and seal the through hole (81). The pressure supply unit includes an upper cavity (1) and a lower cavity (2) communicating with the upper cavity (1). The base (8) is detachably fixed to the lower cavity (2). The upper cavity (1), the lower cavity (2) and the pressure equalization unit together form a closed gas chamber (11). The upper cavity (1) is connected to an air pump via an inlet / outlet pipe (4). The air pump is configured to pump or fill the gas chamber (11) to control the position of the piston (9) within the through hole (81).

2. The battery stack pressurization and positioning device according to claim 1, characterized in that, The inlet and outlet pipes (4) are connected to the air pump via valves (5), which are used to control the air pump to open or close.

3. The battery stack pressurization and positioning device according to claim 1, characterized in that, The base (8) has bolt holes (82) on its side wall, and is fixed to the lower cavity (2) by the cooperation of the connector (10) and bolts (101); the inner wall of the lower cavity (2) is provided with a positioning boss (21), which is used to position the base (8) in the lower cavity (2).

4. The battery stack pressurization and positioning device according to claim 2, characterized in that, The pressure supply unit also includes a pressure sensor (3) installed on the inlet and outlet pipes (4), the pressure sensor (3) being used to measure the gas pressure inside the gas chamber (11); wherein, When the pressure sensor (3) outputs a negative value, the piston (9) is at the uppermost end of the through hole (81), the valve (5) is closed, and the air pump stops pumping air; When the valve (5) is opened, the air pump fills the gas chamber (11) with air, and the piston (9) moves downward in the through hole (81). When the pressure sensor (3) outputs the required operating pressure, the piston (9) located at the top of the battery stack moves to the upper surface of the battery stack and applies uniform pressure to the battery stack.

5. The battery stack pressurization and positioning device according to claim 4, characterized in that, Meanwhile, the piston (9) located on the side wall of the battery stack adheres to the side wall of the battery stack and clamps and positions the battery stack.

6. The battery stack pressurization and positioning device according to claim 1, characterized in that, The battery stack pressurization and positioning device further includes an upper bracket (6) and a lower bracket (7). The upper bracket (6) and the lower bracket (7) are detachably installed on the upper cavity (1). Furthermore, when the upper cavity (1) is installed on the hot box, the upper bracket (6) and the lower bracket (7) can clamp and fix the position of the upper cavity (1) from the outside and the inside of the hot box, respectively.

7. The battery stack pressurization and positioning device according to claim 6, characterized in that, The outer wall of the upper cavity (1) is formed with multiple layers of threads, which are used to adjust the installation position of the upper bracket (6) and the lower bracket (7) according to the height of the battery stack, so as to ensure that the lower end of the piston (9) used for pressurization is in close contact with the upper surface of the battery stack.

8. The battery stack pressurization and positioning device according to claim 1, characterized in that, The piston (9) includes a piston head (91) and a piston rod (92) connected to the end of the piston head (91). The outer surface of the piston head (91) has multiple annular grooves for labyrinth-type gap sealing with the through hole (81).

9. The battery stack pressurization and positioning device according to claim 8, characterized in that, The through hole (81) includes an upper through hole (811), a middle through hole (812), and a lower through hole (813); wherein, The upper through hole (811) is connected to the gas chamber (11), the middle through hole (812) is used to accommodate the piston head (91), and the lower through hole (813) cooperates with the piston rod (92) to close the through hole (81).

10. A method for pressurizing and positioning a battery stack using the battery stack pressurizing and positioning device according to any one of claims 1-9, characterized in that, The method includes: First, select a base (8), base cover plate (83) and piston (9) that match the size of the battery stack. Fix the base (8) and lower cavity (2) with connector (10) and bolt (101). Open the valve (5) on the inlet and outlet pipe (4). Use an air pump to draw the gas chamber (11) into negative pressure so that the piston (9) is at the top of the base through hole (81). Then close the valve (5) on the inlet and outlet pipe (4). Then, install the upper bracket (6) and the lower bracket (7) on the upper cavity (1), place the entire bracket into the hot box where the fuel cell stack is running, and adjust the position of the upper bracket (6) and the lower bracket (7) according to the height of the fuel cell stack. That is, install the upper bracket (6) and the lower bracket (7) along the thread on the outer wall of the upper cavity (1) to the appropriate position so that the lower end of the piston (9) contacts the upper surface of the fuel cell stack. At the same time, the upper bracket (6) and the lower bracket (7) are respectively close to the inner and outer walls of the top shell of the hot box. At this time, the pressure positioning device is fixed to the hot box. When it is necessary to pressurize the battery stack, open the valve (5) on the inlet and outlet pipes (4) and use the air pump to pressurize the gas chamber (11) to the required pressure. The pressure in the gas chamber (11) pushes the piston (9) at the top of the battery stack to pressurize the battery stack. The piston (9) on the side wall of the battery stack clamps and positions the battery stack. In addition, during the operation of the battery stack, the pressure change in the gas chamber (11) is monitored in real time by the pressure sensor (3). The pressure is adjusted by the air pump according to the operating conditions.

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