Vanadium redox flow battery stack assembly system

Abstract

The present invention discloses a vanadium redox flow battery stack assembly system, which includes a stack unit assembly jig for assembling stack units and a seal plate assembly system for assembling the stack seal plates; the seal plate assembly system includes a welding system, a press-fitting fixture, an assembly table, a seal plate welding tooling and a current collector nozzle welding tooling; the press-fitting fixture is used to clamp and press the stack of the laminated structure, and the press-fitting fixture holding the stack is placed on the assembly table. The welding system includes a controller, a moving component and a welding component. The controller controls the moving component to drive the welding component to move so as to perform the welding assembly of the seal plates on the stack on the assembly table. This assembly system helps to assemble the vanadium redox flow battery stack quickly, efficiently and with high quality.

Description

Technical Field

[0001] The present invention relates to a system for producing a vanadium redox flow battery stack. Background Art

[0002] A vanadium redox flow battery is a redox battery in which vanadium is used as an active substance and is in a circulating liquid state. The electrical energy of the vanadium battery is stored in the sulfuric acid electrolyte of vanadium ions in different valence states in the form of chemical energy. The electrolyte is pumped into the battery stack body by an external pump. Under the action of mechanical power, it circulates in a closed loop of different liquid storage tanks and half-cells. A proton exchange membrane is used as the diaphragm of the battery pack. The electrolyte solution flows parallel to the electrode surface and undergoes an electrochemical reaction. The current is collected and conducted through a bipolar plate, thereby realizing the mutual conversion of electrical energy and chemical energy and achieving the charging and discharging of the battery.

[0003] The existing vanadium redox flow battery stack relies on manual assembly, resulting in low production efficiency and unstable quality. Summary of the Invention

[0004] In view of this, the present invention provides a vanadium redox flow battery stack assembly system for efficiently and high-quality assembling a vanadium redox flow battery stack.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows: a vanadium redox flow battery stack assembly system, including a stack unit assembly fixture for assembling stack units and a seal plate assembly system for assembling the stack seal plates; the seal plate assembly system includes a welding system, a press-fitting fixture, an assembly table, a seal plate welding tooling and a bus bar welding tooling; the press-fitting fixture is used to clamp and press the stack of the laminated structure, and the press-fitting fixture holding the stack is placed on the assembly table. The welding system includes a controller, a moving component and a welding component. The controller controls the moving component to drive the welding component to move for welding and assembling the seal plates of the stack on the assembly table. The battery unit assembly fixture is used to ensure the assembly accuracy and stability of the stack units. The stack seal plate assembly system adopts an automatic welding method to implement the assembly of the seal plates. The seal plates are perpendicular to the battery units and diaphragms in the stack, and the seal plates are welded and connected to the entire surface of the side of the stack in the stacking direction, that is, the seal plates need to be completely welded and connected to each battery unit. Therefore, the routing path of the welding component needs to cover the entire area of the stack side. The moving component drives the welding component to perform welding routing under the control of the controller, with high automation and efficiency, which can effectively ensure the welding accuracy and quality. The stack of the laminated structure is placed on the assembly table in a state of being effectively pressed and then the seal plates are welded and assembled, which can ensure that the laminated components of the stack fit tightly, thus ensuring the assembly quality of the stack. The seal plates are welded and connected to the side of the stack in the stacking direction in a state where the laminated components of the stack fit tightly, which can effectively ensure the assembly accuracy and quality, ensure the connection tightness, avoid the leakage of electrolyte penetration in the flow battery, and ensure the performance and service life of the flow battery.

[0006] As an improvement, the stack unit assembly fixture includes a carrying platform and a limiting component arranged on the carrying platform. The limiting component includes a fixed limiting part and a movable limiting part. The fixed limiting part is fixedly arranged on the carrying platform, and the movable limiting part is movably adjustable along the surface of the carrying platform in the direction towards the fixed limiting part. The part to be processed is limited between the fixed limiting part and the movable limiting part. The stack unit assembly fixture uses the carrying platform to carry and place the part to be processed, and positions the part to be processed through the fixed limiting part and the movable limiting part. The part to be processed is accurately limited and high stability is ensured during the welding process, thereby effectively ensuring the assembly accuracy, improving the assembly quality, and further ensuring the good performance of the flow battery. And the position of the movable limiting part is adjustable, that is, the distance between the fixed limiting part and the movable limiting part can be adjusted to match parts to be processed of different sizes, with good flexibility and wide application range.

[0007] As an improvement, the fixed limiting part includes two limiting bars perpendicular to each other. There are two sets of the movable limiting parts, which are respectively matched with one limiting bar, and the movable limiting parts are movably adjustable in the direction perpendicular to the limiting bar; the movable limiting part includes a push plate and a telescopic driving mechanism for driving the push plate to move. The structure is simple and convenient to use. The two mutually perpendicular limiting bars can accurately limit the parts to be processed in two directions, thus ensuring the accuracy of welding processing. The push plate matches the edge of the part to be processed, and the telescopic driving mechanism controls the position of the push plate, so as to adapt to parts to be processed with different sizes.

[0008] As a preference, it further includes a pressing plate, and the pressing plate is used to cover the part to be processed limited between the fixed limiting part and the movable limiting part; it further includes a pressing block, and the pressing block is used to be placed on the top surface of the pressing plate covering the part to be processed. The pressing plate is used to ensure the flatness of the splicing of the parts to be processed, so that the parts to be processed are evenly and tightly attached to each other on the entire plane, avoiding misalignment, warping and lifting between the parts to be processed that are spliced with each other, improving the welding tightness, improving the assembly accuracy of the parts to be processed, improving the stability of the parts to be processed during the welding process, avoiding displacement, and improving the processing quality of the flow battery unit. The pressing block is used to increase the pressing force on the part to be processed, further ensuring that the parts to be processed are evenly and tightly attached to each other on the entire plane, ensuring the stability of the parts to be processed during the entire welding process, thereby improving the assembly accuracy and the production quality of the flow battery unit. Moreover, the pressing block has good flexibility in use, can be placed at different positions according to parts to be processed with different sizes, and can also flexibly select different quantities.

[0009] As an improvement, the press-fitting fixture includes a tie rod assembly and two parallel clamping plates. The clamping plates are provided with connecting seats extending outward from the outer side of the edge of the clamping plates. The connecting seats are spaced at several intervals in the entire circumference of the edge of the clamping plates. The two ends of the tie rod assembly are respectively connected to the connecting seats on the two clamping plates, so that the two clamping plates tightly press and fix the stack located between the clamping plates and with the stacking direction perpendicular to the clamping plates. The clamping plates connected by the tie rod assembly of the press-fitting fixture can fully press the stack. Since the connecting seats are spaced at several intervals in the entire circumference of the edge of the clamping plates, the corresponding connecting seats on the two clamping plates are respectively connected by the tie rod assembly, ensuring that the two clamping plates can apply a uniform and stable pressing force on the entire plane of the stacked battery cells and diaphragms, ensuring that the stacked battery cells and diaphragms can be fully and tightly attached, ensuring the sealing performance, ensuring that the battery cells are effectively separated by the diaphragms, avoiding the situation of mutual seepage of the electrolytes of the positive and negative electrodes, ensuring the performance reliability of the flow battery, and the outwardly extending connecting seats reserve enough space for the assembly of the sealing plate, avoiding interference with the welding device for welding the sealing plate, ensuring that the assembly of the sealing plate can be carried out reliably, and further ensuring the assembly accuracy and sealing performance of the sealing plate.

[0010] As an improvement, a limiting stop member perpendicular to the clamping plate is connected to the edge of at least one of the clamping plates. The limiting stop member is used to limit and align the edge of the stack. The limiting stop member includes a limiting baffle and a limiting strip. The limiting baffle is located at the long edge of the rectangular clamping plate and covers the entire length of the long edge. The limiting strip is located at the short edge of the clamping plate and covers a partial length of the short edge. The stack includes a plurality of stacked stack units and diaphragms. The limiting stop member is used to form an alignment reference. The battery units and the diaphragms are both abutted against the limiting stop member to ensure the stacking neatness of the battery units and the diaphragms and improve the assembly accuracy. Since the limiting stop member is located at the edge of the clamping plate, the limiting stop member will not interfere with the mutual approach of the two clamping plates under the action of the tie rod assembly, and no unnecessary interference will occur, ensuring that the pressing fixture can reliably press the stack. And it can align multiple edges of the stacked battery units and diaphragms, improving the alignment effect of the battery units and the diaphragms.

[0011] As a preference, a groove is formed on the side of the limiting strip facing the stack. A top strip is arranged in the groove. A screw hole communicating with the groove is formed on the side of the limiting strip facing away from the stack. A top push bolt device is installed in the screw hole to push the top strip to align the edge of the stack. A through hole communicating with the groove is formed on the side of the limiting strip facing away from the stack. A connecting rod connected to the top strip passes through the through hole.

[0012] As an improvement, the assembly table includes a base and a turntable rotatably arranged on the base. The pressing fixture holding the stack is placed on the turntable. A locking mechanism for locking the turntable after it rotates in place is further arranged between the base and the turntable. The locking mechanism includes a telescopic pin assembly and a locking portion. At least one of the telescopic pin assembly and the locking portion is distributed with a plurality of parts at intervals along the circumferential direction of the rotation of the turntable. The telescopic pin assembly is arranged on the turntable or the base, and the locking portion is arranged on the other of the turntable and the base. The assembly table uses the turntable to drive the pressing fixture holding the stack to rotate, thereby adjusting the orientation of the stack, facilitating the assembly and other processing of the sealing plate on each side of the stack, replacing the traditional hoisting and moving method, with higher moving safety, no risk of the pressing fixture holding the stack falling, more convenient and accurate moving, ensuring the sealing plate assembly accuracy, thus ensuring the assembly sealing performance, effectively avoiding the leakage of the electrolyte during the use of the flow battery. The pressing fixture and the turntable are positioned through a positioning mechanism, thus ensuring a stable and high-precision positional relationship between the pressing fixture and the turntable, avoiding the relative offset between the pressing fixture holding the stack and the turntable during the rotation process, ensuring that the stack can be accurately rotated in place when the turntable rotates in place, and further ensuring the sealing plate assembly accuracy.

[0013] As an improvement, the sealing plate welding tooling includes a frame-shaped sealing plate pressing die and a sealing plate pressing light-transmitting layer made of a light-transmitting material; the sealing plate, the sealing plate pressing light-transmitting layer and the sealing plate pressing die are arranged in sequence from the side of the stack outward, the sealing plate pressing light-transmitting layer covers the entire sealing plate, the sealing plate pressing die is screwed to the edge of the pressing fixture, and the sealing plate pressing die presses the edge of the sealing plate pressing light-transmitting layer so that the sealing plate pressing light-transmitting layer tightly presses the sealing plate against the side of the stack. The structure is simple, and it can apply uniform pressure covering the entire surface of the sealing plate to ensure that the entire surface of the sealing plate is closely attached to the side of the stack, thereby improving the welding quality and sealing performance.

[0014] As an improvement, the bus bar welding tooling includes a frame-shaped bus bar pressing die, and a bus bar pressing light-transmitting layer I made of a light-transmitting material is fixed on the bus bar pressing die; behind the bus bar pressing die is a bus bar pressing light-transmitting layer II made of a light-transmitting material; a hollow-out matching the shape of the bus bar electrolyte cavity is arranged on the bus bar pressing light-transmitting layer II; the bus bar pressing die is fixed on the pressing fixture of the stack. It is convenient and fast to position and press the bus bar tightly on the sealing plate for quick welding. It greatly reduces the labor intensity of workers and improves the welding quality.

[0015] The advantages of the present invention are as follows: for the stack assembly system with the above structure, after the high-quality stack units assembled by the stack unit assembly fixture are stacked into a stack, the stack is automatically assembled with the sealing plate in a state of being effectively pressed. It has high processing efficiency, high assembly accuracy and good quality, can ensure that the laminated components of the stack are closely attached to each other, ensure that the sealing plate can be effectively welded to the laminated components of the stack, improve the assembly sealing performance, avoid the situation of electrolyte penetration and leakage in the flow battery, and ensure the performance and service life of the flow battery;

[0016] The turntable is used to drive the pressing fixture holding the stack to rotate to adjust the orientation of the stack, so that the sealing plate can be assembled on different sides of the stack flexibly and conveniently. The movement reliability and accuracy of the stack are high, which ensures the sealing plate assembly accuracy and the assembly sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the stack unit assembly fixture in the present invention.

[0018] Figure 2 It is the general drawing of the sealing plate assembly system in the present invention;

[0019] Figure 3 It is a schematic structural diagram of the assembly table;

[0020] Figure 4 It is a schematic diagram of the cooperation between the pressing fixture and the first set of positioning holes on the turntable;

[0021] Figure 5 Schematic diagram of the fitting between the press-fitting fixture and the second set of positioning holes on the turntable;

[0022] Figure 6 Schematic structural diagram of the press-fitting fixture;

[0023] Figure 7 Schematic diagram of pre-fixing the sealing plate to the stack;

[0024] Figure 8 Side view structural diagram of the sealing plate welding tooling;

[0025] Figure 9 Schematic structural diagram of the sealing plate press-fitting die;

[0026] Figure 10 Side view structural diagram of the busbar welding tooling;

[0027] Figure 11 Top view of press-fitting the light-transmitting layer II of the busbar. Specific implementation manners

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with specific implementation manners.

[0029] The present invention includes a stack unit assembly jig for assembling stack units and a sealing plate assembly system for assembling the stack sealing plate;

[0030] As Figure 1 shown, the stack unit assembly jig includes a bearing platform 101 and a limiting component arranged on the bearing platform 101. The limiting component includes a fixed limiting part 102 and a movable limiting part 103. The fixed limiting part 102 is fixedly arranged on the bearing platform 101. The movable limiting part 103 is movably adjustable along the surface of the bearing platform 101 in the direction towards the fixed limiting part 102, and the part to be processed is limited between the fixed limiting part 102 and the movable limiting part 103.

[0031] The flow battery unit in this embodiment is composed of a current collector plate, a bipolar plate assembly and a current collector plate stacked in sequence. The bipolar plate assembly is composed of a bipolar plate, an insulating frame and a fixing frame. Both the insulating frame and the fixing frame are frame-shaped structures with a hollow middle. The insulating frame surrounds the entire outer edge of the bipolar plate. One fixing frame is provided on each of the front and back sides of the bipolar plate, and the fixing frame is hermetically connected to the bipolar plate and the insulating frame respectively in the entire circumferential direction of the bipolar plate edge;

[0032] The assembly of the flow battery unit includes the welded connection of bipolar plates, insulating frames, and fixing frames. After obtaining the bipolar plate assembly through assembly, the bipolar plate assembly is then welded to the flow guide plate. Both of the above two welding and assembly processes are completed using the flow battery unit assembly jig described in this embodiment.

[0033] Specifically, the flow battery unit is a rectangular laminated structure. The fixed limiting part 102 includes two mutually perpendicular limiting strips, and the two limiting strips are spliced into a right-angle structure. There are two sets of the movable limiting parts 103, which are respectively matched with one limiting strip. The movable limiting part 103 is movably adjustable in the direction perpendicular to the limiting strip. Moreover, each set of the movable limiting parts 103 includes several spaced apart in the direction perpendicular to the moving direction. In this embodiment, each set of the movable limiting parts 103 is specifically provided with two, and the two movable limiting parts 103 are adjusted synchronously. That is, no matter how they are adjusted, the distances from the two movable limiting parts 103 to the limiting strip are always the same.

[0034] The movable limiting part 103 includes a push plate and a telescopic driving mechanism for driving the push plate to move. The telescopic driving mechanism is specifically a cylinder, which has a simple structure, is convenient and flexible to adjust, and has high precision.

[0035] The flow battery unit assembly jig further includes a pressing plate 4 and a pressing block 5. The pressing plate 4 is used to cover the workpiece to be processed limited between the fixed limiting part 102 and the movable limiting part 103, so that the workpieces to be processed are evenly and tightly attached to each other on the entire plane. The pressing block 105 is used to be placed on the top surface of the pressing plate 104 covering the workpiece to be processed to increase the pressing force, and further make the workpieces to be processed evenly and tightly attached to each other on the entire plane. The pressing plate 4 is made of a transparent material, and specifically, an acrylic plate can be used. The pressing plate 104 completely presses the welding part, and the welding laser can pass through the pressing plate 4 to perform welding operations on the workpiece to be processed under the pressing plate. The pressing block 105 is magnetically attracted to the bearing platform 101 to increase the pressing force on the workpiece to be processed, thereby improving the assembly accuracy and welding quality of the workpiece to be processed. Moreover, the surface of the pressing block 105 is wrapped with a flexible layer to avoid damaging the workpiece to be processed, the pressing plate, etc. when the pressing block falls, collides, etc., improve the use safety, and ensure the integrity of the workpiece to be processed and the pressing plate.

[0036] When performing the welding and assembly of the bipolar plate, the insulating frame and the fixing frame, first adjust the movable limiting part 3 so that the distance between the movable limiting part 103 and the fixed limiting part 102 reaches the required size. Then, place the bipolar plate and the insulating frame on the bearing platform 101 between the movable limiting part 103 and the fixed limiting part 102, and place them flat so as to closely adhere to the bearing platform 101. The insulating frame is located on the periphery of the bipolar plate and is in direct close contact with the movable limiting part 103 and the fixed limiting part 102. Then, place the fixing frame on top of the bipolar plate and the insulating frame. The periphery of the fixing frame is in close contact with the movable limiting part 103 and the fixed limiting part 102. Then, place the pressing plate 104 to ensure the flatness of the splicing of the bipolar plate, the insulating frame and the fixing frame, and then place the pressing block 105 to further press tightly. Finally, the laser welding device welds and fixes the bipolar plate, the insulating frame and the fixing frame together according to the preset path. After the welding and assembly of this surface are completed, remove the pressing block 105 and the pressing plate 104, then turn the semi-finished product over and place it on the bearing platform 101 between the movable limiting part 103 and the fixed limiting part 102. Then, place another fixing frame on top of the bipolar plate and the insulating frame, and then place the pressing plate 104 and the pressing block 105 again. The laser welding device welds and fixes the bipolar plate, the insulating frame and the fixing frame together according to the preset path again, and finally completes the bipolar plate assembly.

[0037] When assembling the flow battery unit, first place the bipolar plate assembly on the bearing platform 101 between the movable limiting part 103 and the fixed limiting part 102. The bipolar plate assembly needs to be placed flat so as to closely adhere to the bearing platform 101. The periphery of the bipolar plate assembly is in close contact with the movable limiting part 103 and the fixed limiting part 102. Then, place the flow guide plate on top of the bipolar plate assembly. The periphery of the flow guide plate is in close contact with the movable limiting part 103 and the fixed limiting part 102. Then, place the pressing plate 104 and the pressing block to press the flow guide plate and the bipolar plate assembly tightly, so that the flow guide plate and the bipolar plate assembly are evenly and closely attached on the entire plane. The laser welding device welds and fixes the flow guide plate and the bipolar plate assembly together. After the welding and assembly of this surface are completed, remove the pressing block 105 and the pressing plate 104, then turn the semi-finished product over and place it on the bearing platform 101 between the movable limiting part 103 and the fixed limiting part 102. Then, place another flow guide plate on top of the bipolar plate assembly, and then place the pressing plate 104 and the pressing block 105 again. The laser welding device works again to weld and fix the flow guide plate and the bipolar plate assembly together, and finally completes the flow battery unit.

[0038] As Figures 2 - 11As shown in the figure, the sealing plate assembly system includes a welding system 1, a press-fitting fixture 2, an assembly table 3, a sealing plate welding tooling, and a 7-busbar welding tooling; the press-fitting fixture 2 is used to clamp and press the stack 4 of the laminated structure. The press-fitting fixture 2 holding the stack is placed on the assembly table 3. The welding system 1 includes a controller 11, a moving component 12, and a welding component 13. The controller 11 controls the moving component 12 to drive the welding component 13 to move for welding and assembling the sealing plate 6 on the stack 4 on the assembly table 3. The controller 11 includes a main control unit and a human-machine interface, etc. The moving component drives the welding component to perform welding traces under the control of the controller, and automatically welds and connects the sealing plate to the side of the stack.

[0039] In order to further improve the assembly efficiency, several groups of the moving component 12 and the welding component 13 are provided to simultaneously perform welding and assembling of the sealing plate on the stack 4. It can be to simultaneously perform welding and connection of the sealing plate on the same side of the stack 4, or to simultaneously perform welding and connection of the sealing plate on different sides of the stack 4. In this embodiment, it is preferably to adopt the method of simultaneously performing welding and connection of the sealing plate on different sides of the stack 4. Specifically, a total of two groups of the moving component 12 and the welding component 13 are provided, and these two groups of the moving component 12 and the welding component 13 are distributed on two opposite sides of the stack. The two moving components 12 respectively drive the welding components 13 connected thereto to simultaneously perform welding and assembling on two opposite sides of the stack 4. In this embodiment, the moving component 12 adopts a robotic arm, and the welding component 13 is a laser welding mechanism. And during the welding process, the moving component 12 drives the welding component 13 to perform pressure welding, that is, the welding component 13 applies pressure to the welding position so that the sealing plate closely adheres to the side of the stack 4, thereby ensuring that the sealing plate can be stably welded to the side of the stack, improving the sealing plate assembly accuracy, improving the assembly tightness, and avoiding the situation of electrolyte penetration and leakage.

[0040] In this embodiment, the assembly table 3 mainly includes a base 31 and a turntable 32 rotatably provided on the base 31. A toothed ring is provided on the turntable 32 along the circumferential direction of rotation. The driving mechanism drives the turntable 32 to rotate through a gear meshing with the toothed ring. The press-fitting fixture 2 holding the stack 4 is placed on the turntable 32, and the press-fitting fixture 2 and the turntable 32 are limited by a positioning mechanism 5 to ensure the accuracy of placing the press-fitting fixture 2 on the turntable 32. At the same time, it also avoids relative displacement between the press-fitting fixture 2 and the turntable 32 during the rotation of the turntable 32. Further, it can also avoid the stack from shifting during the welding and assembling process, ensuring that the position of the stack is always stable, thereby ensuring the welding and assembly accuracy of the sealing plate.

[0041] Specifically, the positioning mechanism 5 includes a positioning pin and a positioning hole that cooperates with it. The positioning pin is provided on the press-fitting fixture 2, and the positioning hole is provided on the turntable 32. There are two sets of positioning holes on the turntable 32. When the press-fitting fixture 2 clamping the stack 4 cooperates with the two sets of positioning holes respectively, the stack 3 faces different directions, and the two directions are perpendicular to each other. Specifically, as Figure 3 and Figure 4 shown, the press-fitting fixture 2 is generally rectangular in structure, and the stack 4 clamped in the press-fitting fixture 2 is also rectangular in structure. That is to say, the side surface of the stack where the sealing plate is to be assembled includes a long side and a short side. The positioning pin is arranged in the diagonal direction of the press-fitting fixture 2. Correspondingly, a positioning hole that cooperates with the positioning pin is arranged on the turntable. The first set of positioning holes on the turntable makes the long side of the stack on the press-fitting fixture 2 face the welding processing device, and the second set of positioning holes on the turntable makes the short side of the stack on the press-fitting fixture 2 face the welding processing device. Thus, the stack can reach the accurate position even when the turntable does not rotate, ensuring the accuracy and quality of the sealing plate processing.

[0042] In this embodiment, a locking mechanism 33 for locking the turntable 2 after it rotates in place is further provided between the base 31 and the turntable 32, further ensuring the accuracy of the turntable in place and preventing the turntable from shifting during the assembly of the sealing plate. The locking mechanism 33 includes a telescopic pin assembly 331 and a locking portion 332. At least one of the telescopic pin assembly 331 and the locking portion 332 is distributed at intervals along the circumferential direction of the rotation of the turntable 32. The telescopic pin assembly 331 is provided on the base 31, and the locking portion 332 is provided on the turntable 32. Specifically, the locking portion 332 is a V-shaped groove, and the telescopic pin assembly 331 includes a wedge-shaped pin head that matches the V-shaped groove. When the wedge-shaped pin is inserted into the V-shaped groove, the inclined surfaces of the V-shaped groove and the wedge-shaped pin head can generate a pushing force on the turntable, thereby causing the turntable to rotate slightly to reach a high-precision position, making the stack reach an accurate orientation, and thus improving the accuracy of the sealing plate assembly.

[0043] Such as Figure 5As shown in the figure, the press-fitting fixture 2 includes a pull rod assembly 22 and two parallel clamping plates 21. A connecting seat 23 extending outward from the outer edge of the clamping plate 21 is provided on the clamping plate 21. The clamping plate 21 is specifically rectangular. One connecting seat 23 is provided at each of the four vertex angles of the clamping plate 21. The connecting seat is fixed to the pressing plate by welding. Both ends of the pull rod assembly 22 are connected to the connecting seats 23 on the two clamping plates 21 respectively, so that the two clamping plates 21 can move towards each other to achieve the pressing function. Specifically, the clamping plate 21 is parallel to the battery cells and diaphragms in the stack 4, that is, the clamping plate 21 is perpendicular to the stacking direction of the stack 4. The clamping plates 21 are arranged on both sides of the stack 4 in the stacking direction. Under the action of the pull rod assembly 22, the two clamping plates 21 press and fix the stack 4 located between the pressing plates. The pull rod assembly 22 is along the stacking direction of the stack a. The pull rod assembly 22 specifically includes a pull rod and a nut. The pull rod is in a straight rod shape, and a limiting cap portion with an outer dimension larger than the diameter of the pull rod is provided at one end, and a threaded section is provided at the other end. The limiting cap portion at one end of the pull rod is stuck on the connecting seat of a pressing plate, and the other end of the pull rod is stuck on the connecting seat of another pressing plate after the nut is sleeved. By screwing the nut, the two pressing plates are pulled in, so as to press and fix the stack located between the two pressing plates. Moreover, a notch groove 24 matching with the pull rod assembly 22 is opened at the edge of the connecting seat 23. The pull rod of the pull rod assembly 22 can be inserted into the notch groove along the plane direction of the clamping plate 21, which improves the convenience of installation and disassembly of the pull rod assembly 22.

[0044] In this embodiment, three reinforcing strips 25 are further provided on the surface of the clamping plate 21 facing away from the stack 4. The three reinforcing strips 25 are arranged in parallel at intervals, which improves the structural strength of the pressing plate and the flatness of the pressing plate, so as to ensure that the stacked battery cells and diaphragms can be evenly and tightly attached on the entire plane, and improve the quality of the stacked assembly.

[0045] The sealing plate is larger in area than the welding area. After the welding assembly is completed, the part of the sealing plate outside the welding area needs to be removed. When implementing the welding assembly of the sealing plate, first attach a soldering aid layer to the side of the sealing plate 6 facing the stack, and then pre-fix the sealing plate 6 to the side of the stack 4. The edge of the sealing plate 6 can be temporarily fixed to the stack or the press-fitting fixture 2 by means of tape or the like. Then the controller 11 controls the moving assembly 12 to drive the welding assembly 13 to first weld a number of spaced pre-connection welding lines on the sealing plate 6, such as Figure 6As shown, specifically, it can be the pre-connected welding wires 8 which are three straight line segments running horizontally, and the three pre-connected welding wires are distributed at intervals vertically, so as to further pre-fix the sealing plate to the stack. Then, the controller 11 controls the moving component 12 to drive the welding component 13 to walk in a scanning manner to perform a whole-surface welding connection between the sealing plate 6 and the side surface of the stack 4. Under the action of the moving component 12, the welding component 13 applies pressure to the sealing plate 6 during the welding process so that the sealing plate 6 closely adheres to the side surface of the stack 4 at the welding position. The walking mode of the moving component 12 driving the welding component 13 can specifically be to start from the "0" position at the upper left corner of the welding area and perform horizontal welding from left to right to form a straight welding wire. Then, the welding component 13 displaces downward by a certain distance and then performs horizontal welding from left to right again to form the second straight welding wire. By repeating this process, the whole-surface welding connection is achieved. The distance between adjacent two straight welding wires is 0.5 - 2 mm.

[0046] In order to improve the welding and assembly quality of the sealing plate 6, a pressing mechanism 7 for tightly pressing the sealing plate 6 on the stack 4 can also be connected to the edge of the clamping plate 21. Specifically, the pressing mechanism 7 includes a pressing piece 71 and a transparent plate 72. The sealing plate 6, the transparent plate 72, and the pressing piece 71 are arranged in sequence from the side surface of the stack 4 outward. The transparent plate 72 covers the entire sealing plate 6. There are screw holes opened at the edge of the clamping plate 21. The pressing piece 71 is screwed to the edge of the clamping plate 21. The pressing piece 71 presses the edge part of the transparent plate 72 so that the transparent plate 72 tightly presses and fits the sealing plate 6 on the side surface of the stack. The pressing piece 71 can be several sheet materials covering a small distance of the edge of the transparent plate 72. The pressing piece 71 can also be a frame-like structure covering the entire edge of the transparent plate 72. The hollow area in the middle of the frame-like structure is the welding area of the sealing plate. Through the pressing mechanism 7, it can further ensure that the sealing plate 6 evenly and tightly adheres to the side surface of the stack on the whole surface, improve the welding and assembly quality of the sealing plate, ensure that the sealing edge is tightly connected to the stack on the whole surface, improve the assembly sealing performance, and effectively avoid the situation of electrolyte leakage and penetration in the flow battery. The laser of the welding component 13 can directly pass through the transparent plate 72 and then act on the sealing plate, so that the soldering aid layer between the sealing plate and the stack melts to weld the sealing plate and the stack together.

[0047] After the sealing plate is welded, the busbar nozzle 20 needs to be welded. The busbar nozzle 20 is arranged on the sealing plate 6 with a busbar port. In order to improve the welding and assembly quality of the busbar nozzle 20, a busbar nozzle welding tooling can also be set. The busbar nozzle welding tooling includes a frame-shaped busbar nozzle pressing die 404, and a busbar nozzle pressing light-transmitting layer I 409 made of a light-transmitting material is fixed on the busbar nozzle pressing die 404; the busbar nozzle pressing light-transmitting layer I 409 and the busbar nozzle pressing die 404 can be fixed by means of clamping, bonding, etc., and there is no limitation in this application. Behind the busbar nozzle pressing die 404 is a busbar nozzle pressing light-transmitting layer II 405 made of a light-transmitting material; a hollow-out matching the shape of the electrolyte cavity of the busbar nozzle 20 is arranged on the busbar nozzle pressing light-transmitting layer II 405; the busbar nozzle pressing die 404 is fixed on the stack pressing fixture 2.

[0048] In this embodiment, the busbar nozzle pressing die 404 is preferably square, because the busbar nozzle 20 itself is also rectangular. Of course, the busbar nozzle pressing die 404 can also be of other shapes as long as it can play the role of pressing and positioning.

[0049] The busbar nozzle pressing light-transmitting layer II 405 is divided into two parts on the left and right, and is connected and positioned with the busbar nozzle pressing die 404 by bolts 406. The hollow-out 451 on the busbar nozzle pressing light-transmitting layer II 405 is rectangular, matching the shape of the electrolyte cavity of the busbar nozzle 20. A screw hole is arranged at the upper part of the busbar nozzle pressing light-transmitting layer II 405, and a bolt groove is arranged at the lower edge, which is convenient for assembly. In order to facilitate demolding, the four corners of the hollow-out 451 can be subjected to hole expansion treatment.

[0050] For the material selection, in this embodiment, the busbar nozzle pressing die 404 is made of aluminum alloy, the busbar nozzle pressing light-transmitting layer I 409 is made of glass, and the busbar nozzle pressing light-transmitting layer II 405 is made of acrylic or other transparent organic polymer plastics.

[0051] During operation, first press-fit the light-transmitting layer I 409 of the busbar nozzle into the busbar nozzle press-fitting mold 404 for fixation. Then, insert bolts 406 through the bolt holes at the bottom of the busbar nozzle press-fitting mold 404, and screw the bolts into the stack press-fitting fixture 2, leaving a gap in the middle. Apply soldering flux on the back of the bottom plate of the busbar nozzle 20. Then, insert the busbar nozzle 20 into the light-transmitting layer II 405 of the busbar nozzle press-fitting and place it in the gap of the busbar nozzle press-fitting mold 404. Align the bottom bolt groove 410 of the light-transmitting layer II 405 of the busbar nozzle press-fitting with the bottom bolts. Insert the upper bolts sequentially through the screw holes 408 on the busbar nozzle press-fitting mold 404 and the light-transmitting layer II 405 of the busbar nozzle press-fitting, and tighten all the bolts 406. Note that the electrolyte chamber of the busbar nozzle 20 should be clamped in the hollow 451 of the light-transmitting layer II 405 of the busbar nozzle press-fitting. The pressure is transmitted to the busbar nozzle 20 through the busbar nozzle press-fitting mold 404, the light-transmitting layer I 409 of the busbar nozzle press-fitting, and the light-transmitting layer II 405 of the busbar nozzle press-fitting, providing a pre-pressure to the busbar nozzle 20, so that the soldering layer on the bottom plate of the busbar nozzle 20 is in close contact with the sealing plate 6. In this way, when welding, the soldering layer heats up and melts, and at the same time, the surfaces of the sealing plate 6 and the bottom plate of the busbar nozzle 20 are melted and softened, and are tightly combined under the action of the pre-pressure.

[0052] The above is only the preferred embodiment of the present invention. It should be noted that the above preferred embodiment should not be construed as a limitation of the present invention. The protection scope of the present invention should be determined by the scope defined in the claims. For those of ordinary skill in the art, several improvements and refinements can be made without departing from the spirit and scope of the present invention, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A vanadium redox flow battery stack assembly system, characterized in that: It includes a stack unit assembly fixture for assembling stack units and a header plate assembly system for assembling stack header plates; the header plate assembly system includes a welding system, a press-fitting fixture, an assembly table, a header plate welding tooling, and a bus bar welding tooling; the press-fitting fixture is used to clamp and press the stack of the laminated structure, and the press-fitting fixture holding the stack is placed on the assembly table. The welding system includes a controller, a moving component, and a welding component. The controller controls the moving component to drive the welding component to move for welding and assembling the header plate of the stack on the assembly table. The press-fitting fixture includes a pull rod assembly and two parallel clamping plates. The clamping plates are provided with connecting seats extending outward from the outer side of the edge of the clamping plates; at least at the edge of one of the clamping plates, a limiting stop perpendicular to the pressing plate is further connected. The limiting stop is used to limit and align the edge of the stack. The limiting stop includes a limiting baffle and a limiting strip. The limiting baffle is located at the long edge of the rectangular pressing plate and covers the entire length of the long edge. The limiting strip is located at the short edge of the clamping plate and covers a partial length of the short edge. A groove is provided on the side of the limiting strip facing the stack, and a top strip is arranged in the groove. A screw hole communicating with the groove is provided on the side of the limiting strip facing away from the stack. A top-pushing bolt device is installed in the screw hole to push the top strip to align the edge of the stack. A through hole communicating with the groove is provided on the side of the limiting strip facing away from the stack, and a connecting rod connected to the top strip passes through the through hole. The stack unit assembly fixture includes a carrying platform and a limiting component arranged on the carrying platform.

2. The vanadium redox flow battery stack assembly system according to claim 1, characterized in that: The limiting component includes a fixed limiting part and a movable limiting part. The fixed limiting part is fixedly arranged on the carrying platform. The movable limiting part is movably adjustable along the surface of the carrying platform in the direction towards the fixed limiting part. The part to be processed is limited between the fixed limiting part and the movable limiting part.

3. The vanadium redox flow battery stack assembly system according to claim 2, characterized in that: The fixed limiting part includes two mutually perpendicular limiting strips. There are two groups of movable limiting parts, which are respectively matched with one limiting strip. The movable limiting part is movably adjustable in the direction perpendicular to the limiting strip. The movable limiting part includes a pushing plate and a telescopic driving mechanism for driving the pushing plate to move.

4. The vanadium redox flow battery stack assembly system according to claim 2, characterized in that: It further includes a pressing plate, which is used to cover the part to be processed limited between the fixed limiting part and the movable limiting part; it further includes a pressing block, which is used to be placed on the top surface of the pressing plate covering the part to be processed.

5. The vanadium redox flow battery stack assembly system according to claim 1, characterized in that: The connecting seats are arranged at intervals in the entire circumferential direction of the edge of the clamping plate. The two ends of the pull rod assembly are respectively connected to the connecting seats on the two clamping plates, so that the two clamping plates tightly fix the stack located between the clamping plates and with the lamination direction perpendicular to the clamping plates.

6. The vanadium redox flow battery stack assembly system according to claim 1, characterized in that: The described assembly table includes a base and a turntable rotatably arranged on the base, and a press-fitting fixture clamping the battery stack is placed on the turntable; a locking mechanism for locking the turntable after it rotates in place is further arranged between the base and the turntable. The locking mechanism includes a telescopic pin assembly and a locking part. At least one of the telescopic pin assembly and the locking part is distributed with a plurality of parts at intervals along the circumferential direction of the turntable rotation. The telescopic pin assembly is arranged on the turntable or the base, and the locking part is arranged on the other of the turntable and the base.

7. The vanadium redox flow battery stack assembly system according to claim 1, characterized in that: The described seal plate welding tooling includes a frame-shaped seal plate press-fitting die and a seal plate press-fitting light-transmitting layer made of a light-transmitting material; the seal plate, the seal plate press-fitting light-transmitting layer and the seal plate press-fitting die are sequentially arranged outward from the side of the battery stack. The seal plate press-fitting light-transmitting layer covers the entire seal plate. The seal plate press-fitting die is screwed to the edge of the press-fitting fixture, and the seal plate press-fitting die presses the edge of the seal plate press-fitting light-transmitting layer so that the seal plate press-fitting light-transmitting layer tightly presses the seal plate against the side of the battery stack.

8. The vanadium redox flow battery stack assembly system according to claim 1, characterized in that: The described busbar nozzle welding tooling includes a frame-shaped busbar nozzle press-fitting die, and a busbar nozzle press-fitting light-transmitting layer I made of a light-transmitting material is fixed on the busbar nozzle press-fitting die; Behind the busbar nozzle press-fitting die is a busbar nozzle press-fitting light-transmitting layer II made of a light-transmitting material; a hollow-out matching the shape of the busbar nozzle electrolyte cavity is arranged on the busbar nozzle press-fitting light-transmitting layer II; The busbar nozzle press-fitting die is fixed on the battery stack press-fitting fixture.

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