Sealing positioning structure of flow battery stack and flow battery stack

Abstract

The application discloses a sealing positioning structure of a flow battery stack and the flow battery stack. The sealing positioning structure comprises a sealing body arranged on a first component, a fixing component arranged on the first component and used for fixing the sealing body, a positioning guide arranged on the first component, and a positioning matching component arranged on a second component, wherein the second component is arranged adjacent to the first component, and the positioning matching component is matched with the positioning guide. The fixing component comprises a dovetail groove, and the sealing body comprises an O-shaped sealing ring. The positioning guide and the positioning matching component guide the first component and the second component to be corrected to a predetermined relative position in a stacking process, and make the sealing body be compressed to a sealing interface between the first component and the second component under the predetermined relative position. The application aims to realize automatic alignment and reliable sealing in the stacking process by arranging the sealing body and the positioning guide on the same component.

Description

Technical Field

[0001] This application relates to the field of flow battery energy storage technology, specifically to a sealing and positioning structure for a flow battery stack and the flow battery stack itself. Background Technology

[0002] The flow battery stack is the core component for energy conversion, typically composed of dozens to hundreds of stacked individual cells. Each individual cell includes components such as an electrode frame, bipolar plates, electrodes, a separator, and seals. Two key challenges exist in stack assembly and operation: First, sealing performance is crucial. The electrolyte circulates within the stack's internal channels; seal failure can lead to electrolyte leakage, loss of active materials, cross-contamination, and even electrical short circuits. Second, precise positioning between components is difficult. When stacking numerous thin components, it is essential to ensure alignment of the channels, vias, and sealing surfaces in each layer. Accumulated micro-misalignments can cause channel blockage, increased resistance, and seal shearing, severely impacting stack performance and consistency.

[0003] Currently, traditional sealing methods (such as large-area surface sealing and waterproof adhesive sealing) have drawbacks such as difficult installation, easy detachment of sealing rings, uneven stress, and easy aging. Component positioning relies solely on rough fit between the plates and frames and manual alignment, which is inefficient and highly dependent on the experience of operators, making it difficult to meet the requirements of assembly consistency and reliability for large-scale production.

[0004] Therefore, how to provide a sealing and positioning structure for a flow battery stack and a flow battery stack in order to enable the components of the stack to be automatically and accurately aligned during the stacking and assembly process, while providing a reliable and durable seal, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This application provides a sealing and positioning structure for a flow battery stack and a flow battery stack, which aims to achieve automatic alignment and reliable sealing during stacking by setting the sealing body and the positioning guide on the same component.

[0006] On one hand, this application provides a sealing and positioning structure for a flow battery stack, comprising: a sealing body disposed on a first component; a fixing component disposed on the first component for fixing the sealing body; a positioning guide disposed on the first component; and a positioning mating component disposed on a second component, the second component being adjacent to the first component, the positioning mating component cooperating with the positioning guide; the fixing component includes a dovetail groove, the opening width of the dovetail groove being smaller than the bottom width, and the bottom and wall of the dovetail groove being connected by an arc transition; the sealing body includes an O-ring seal, the O-ring seal being fitted into the dovetail groove; the positioning guide and the positioning mating component guide the first component and the second component to be aligned to a predetermined relative position during the stacking process, and press the sealing body against the sealing interface between the first component and the second component at the predetermined relative position.

[0007] Optionally, in some embodiments of this application, the positioning guide includes at least one of a guide pin, a guide block, or a guide boss, and the positioning guide has a tapered surface or an arc surface for guiding mating; the positioning mating part includes at least one of a guide hole, a guide groove, or a guide recess, and the shape of the positioning mating part is adapted to the shape of the positioning guide.

[0008] Optionally, in some embodiments of this application, the dovetail groove is independently formed on an insert, and the insert is separately disposed from the first component and fixedly installed on the first component.

[0009] Optionally, in some embodiments of this application, the insert is independently manufactured by injection molding, machining or casting processes, and is fixedly fitted into a preset mounting groove on the first component.

[0010] Optionally, in some embodiments of this application, the fixing component includes a groove circumferentially disposed around the edge of the first component, and the sealing body includes a nested sealing ring, the nested sealing ring including a sealing part and a groove part integrally connected, the groove part being fixed in the groove by elastic deformation.

[0011] Optionally, in some embodiments of this application, the sealing portion has continuous ridges, which are used to form a labyrinth seal structure together with the sealing surface of the second component after compression.

[0012] Optionally, in some embodiments of this application, the hardness of the positioning guide is greater than the hardness of the sealing body.

[0013] Optionally, in some embodiments of this application, at least two positioning guides and positioning mating members are respectively provided on the first component and the second component. The positioning guides are arranged diagonally on the edge area of ​​the first component, and the positioning mating members are provided in one-to-one correspondence with the positioning guides.

[0014] On the other hand, this application provides a flow battery stack, including: a plurality of electrode frames and a plurality of bipolar plates stacked alternately; wherein, between adjacent electrode frames and bipolar plates, and / or between two adjacent electrode frames, a sealing positioning structure as described above is provided, wherein one of the electrode frames and the bipolar plates is the first component and the other is the second component.

[0015] The sealing and positioning structure and the flow battery stack provided in this application achieve an automated assembly logic of "positioning first, sealing later" through the coordinated cooperation of positioning guides, positioning mating parts, fixing components, and the sealing body. Specifically, the positioning guides are set on the first component, and the positioning mating parts are set on the adjacent second component. During the stacking process, the two first contact and guide the components to automatically correct themselves to the predetermined position. The fixing components are set on the first component to firmly limit and fix the sealing body to the first component, preventing the sealing body from shifting or falling off during assembly or operation. On this basis, after the components are corrected to the correct position, the sealing body is uniformly pressed against the sealing interface between the first and second components, thereby achieving a reliable seal. Thus, this application not only solves the problems of low efficiency and poor accuracy of traditional manual alignment, greatly improving assembly efficiency and product consistency, but also avoids sealing ring shearing and flow channel blockage caused by misalignment, ensuring the reliability of the seal and the long-term stable operation of the battery stack. Attached Figure Description

[0016] Figure 1 A schematic diagram of the sealing and positioning structure of the flow battery stack provided in the embodiments of this application; Figure 2 A schematic diagram showing the arrangement of the positioning guide on the electrode frame according to an embodiment of this application; Figure 3 A cross-sectional view of the mating state of the positioning guide and positioning mating parts provided in the embodiments of this application during the stacking process; Figure 4 for Figure 1 A partial enlarged cross-sectional view of the dovetail groove assembly and O-ring seal in the sealing and positioning structure; Figure 5 for Figure 1 A partial wireframe diagram of the dovetail groove assembly and O-ring seal in the sealing and positioning structure; Figure 6A partial enlarged cross-sectional view of the nested sealing ring and bipolar plate nested together as provided in an embodiment of this application; Figure 7 This is a three-dimensional schematic diagram of the bipolar plate edge sealing and positioning structure provided in the embodiments of this application. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings. The described technical solutions are for illustrative purposes only and should not be construed as limiting the scope of protection of this application.

[0018] like Figure 1 and Figure 2 As shown, this application provides a sealed positioning structure 100 for a flow battery stack, comprising: The assembly includes a sealing body 110, a fixing component 120, a positioning guide 130, and a positioning mating component 140. The sealing body 110 is disposed on the first component 200 and is used to seal fluid channels (such as electrolyte channels in the electrode area or electrolyte distribution through holes at the edge of the bipolar plate). The fixing component 120 is disposed on the first component 200 and is used to fix the sealing body 110 to prevent the sealing body 110 from shifting or falling off during assembly or operation.

[0019] In the embodiments of this application, the positioning guide 130 is disposed on the first component 200, the positioning mating component 140 is disposed on the second component 300, the second component 300 is disposed adjacent to the first component 200, and the positioning mating component 140 cooperates with the positioning guide 130.

[0020] In the embodiments of this application, during the stacking process (stacked along stacking direction A), the positioning guide 130 and the positioning mating member 140 first contact and guide the first component 200 and the second component 300 to be aligned to a predetermined relative position. Subsequently, the sealing body 110 is pressed against the sealing interface between the first component 200 and the second component 300 at the predetermined relative position. In other words, the core assembly logic of this application is an automated assembly of "positioning guidance first, sealing pressing later," meaning that the relative position of the components has been precisely corrected through the mating of the rigid positioning structure before the sealing body 110 is subjected to the pressing force.

[0021] In the embodiments of this application, the positioning guide 130 and the positioning mating member 140 are mated as follows: the positioning guide 130 is disposed on the first component 200, and the positioning mating member 140 is disposed at the corresponding position on the second component 300, and the two are paired with each other in spatial position.

[0022] In the embodiments of the present application, when the first assembly 200 and the second assembly 300 approach each other along the stacking direction A, the guiding end of the positioning guide 130 first enters the positioning fitting member 140, and the relative position of the assemblies is forcibly corrected by utilizing the shape adaptation relationship between the two. After the assemblies are completely in place, the positioning guide 130 penetrates through or is partially inserted into the positioning fitting member 140, and the sealing main body 110 is just pressed against the preset sealing interface.

[0023] Specifically, the second assembly 300 may be another electrode frame, a bipolar plate, or an end plate, Figure 1 is an exemplary reference.

[0024] In the embodiments of the present application, when a plurality of sealing and positioning structures 100 are disposed on the first assembly 200 and the second assembly 300, each of the sealing and positioning structures 100 works independently, and jointly ensures the sealing and positioning between each layer of the electric stack.

[0025] In the embodiments of the present application, the positioning guide 130 includes at least one of a guide pin, a guide block, or a guide boss. In the embodiments of the present application, the positioning guide 130 is preferably a positioning guide pin, which is cylindrical, but those skilled in the art should understand that the positioning guide 130 may also adopt other shapes. For ease of understanding, the description below will take the positioning guide pin as an example.

[0026] In the embodiments of the present application, the positioning guide 130 has a conical surface or an arc surface for guiding and fitting. The conical or arc-shaped end can provide a large fault-tolerance range at the initial stage of stacking: even if there is a certain initial lateral deviation between the first assembly 200 and the second assembly 300 (that is, a deviation in the XY plane perpendicular to the stacking direction A), the conical end can smoothly enter the positioning fitting member 140, and forcibly correct the position of the assemblies through the action of the inclined surface during the subsequent pressing process.

[0027] In the embodiments of the present application, the cone angle of the conical surface ranges from 15° to 45°, and the values of the cone angle include 15°, 20°, 25°, 30°, 35°, 40°, and 45°. Preferably, the cone angle of the conical surface ranges from 20° to 30°. Within this angle range, sufficient correction force can be provided, without causing jamming due to an excessively large cone angle or an excessively long correction stroke due to an excessively small cone angle. The curvature radius of the arc surface is preferably 0.3 to 0.8 times the root diameter of the positioning guide, and specifically may be 0.3 times, 0.4 times, 0.5 times, 0.6 times, 0.7 times, or 0.8 times, so as to ensure smooth guiding while having sufficient structural strength.

[0028] In embodiments of this application, the positioning mating member 140 includes at least one of a guide hole, a guide groove, or a guide recess, and the shape of the positioning mating member 140 is adapted to the shape of the positioning guide member 130. In embodiments of this application, the positioning mating member 140 is preferably a guide hole (i.e., a positioning mating hole), which can be a through hole (penetrating the thickness direction of the component) or a blind hole (counter-drilled hole), and its inner diameter forms a precision fit with the outer diameter of the root of the positioning guide pin. The fit tolerance is preferably a clearance fit of H7 / g6 or H7 / f7 grade, so as to provide accurate positioning accuracy while ensuring smooth insertion. When the positioning guide member 130 is a guide block, the positioning mating member 140 corresponds to a guide groove (a groove with one end open); when the positioning guide member 130 is a guide boss, the positioning mating member 140 corresponds to a guide recess (a pit that does not penetrate the thickness of the component).

[0029] like Figure 3 As shown, during the stacking process, the tapered guide end 131 of the positioning guide pin first enters the positioning mating hole and begins to perform its automatic correction function. Even if there is an initial lateral deviation, the upper component will be forced to "pull back" to the only correct position by the interaction between the tapered surface of the positioning guide pin and the hole wall of the positioning mating hole, completing precise positioning in the XY plane. Subsequently, the component continues to be pressed downward along the axial direction of the positioning guide pin (i.e., the stacking direction A) until it is fully in place.

[0030] In embodiments of this application, the fixing component 120 includes a dovetail groove 121, the opening width of which is smaller than the bottom width, and the bottom of the dovetail groove 121 is connected to the groove wall by an arc transition. Figure 4 As shown, the dovetail groove 121 has a trapezoidal cross-section. Specifically, its opening width is smaller than the bottom width, meaning the groove wall of the dovetail groove 121 is an inclined surface, presenting an overall shape that is "narrower at the top and wider at the bottom," thus forming a self-locking structure. The included angle α between the groove wall and the bottom is preferably 100° to 130° (i.e., the inclination angle of the groove wall relative to the normal of the bottom is 10° to 40°). The values ​​of the included angle α between the groove wall and the bottom include 100°, 105°, 110°, 115°, 120°, 125°, and 130°. Within this angle range, the dovetail groove can provide sufficient radial limiting force for the O-ring, preventing it from coming out, while avoiding excessive stretching or damage to the O-ring during insertion due to an excessively steep groove wall.

[0031] In the embodiments of this application, a circular arc transition structure is provided at the corner between the bottom and the wall of the dovetail groove 121. The radius of the arc is preferably 0.2 mm to 1.0 mm, and the values ​​of the arc radius include: 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, and 1.0 mm. This circular arc transition structure can prevent the surface of the O-ring 111 from being scratched or cut due to stress concentration during the embedding and subsequent tightening process, thereby extending the service life of the O-ring and ensuring sealing reliability.

[0032] In embodiments of this application, the sealing body 110 includes an O-ring 111, which is fitted into the dovetail groove 121. Figure 4 As shown, the O-ring 111 has a circular cross-section, with a diameter slightly larger than the depth of the dovetail groove 121 (i.e., the distance from the bottom of the groove to the open end face). This allows the O-ring 111 to protrude slightly from the surface of the first component 200, i.e., the electrode frame, after installation, so that it can contact the sealing surface of adjacent components and undergo compression deformation during stacking. The material of the O-ring 111 can be selected as an elastomer resistant to electrolyte corrosion, such as ethylene propylene diene monomer (EPDM), fluororubber (FKM), or perfluoroether rubber (FFKM). Its hardness is preferably Shore A hardness of 60 to 90 degrees, with hardness values ​​including Shore A hardness of 60, 70, 80, and 90 degrees, to maintain good elastic recovery while providing sufficient sealing pressure.

[0033] In the embodiments of this application, since the opening width of the dovetail groove 121 is smaller than the bottom width, the geometry of the dovetail groove 121 plays a crucial radial and axial limiting role for the O-ring 111: on the one hand, it prevents the O-ring 111 from being accidentally displaced or detached due to fluid pressure, vibration, or gravity during assembly or operation; on the other hand, during electrical stacking, the inclined groove wall of the dovetail groove 121 provides precise guidance and constraint for the uniform compression of the O-ring 111, ensuring that its compression deformation is controllable along a predetermined direction and preventing the ring from twisting or rolling during compression. The O-ring 111 undergoes elastic deformation under pressure, filling the microscopic unevenness on the sealing surface, thereby achieving a reliable static seal. The compression ratio of the O-ring 111 is preferably between 15% and 30%, with specific values ​​including: 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, and 30%. Within this compression ratio range, reliable sealing performance can be guaranteed while preventing premature fatigue failure of the O-ring due to excessive compression.

[0034] like Figure 5As shown, the dovetail groove 121 is independently formed on an insert, and the insert is separately set and fixedly installed on the first component 200.

[0035] Specifically, the dovetail groove 121 is not directly integrally formed on the electrode frame body as in Embodiment 1. Instead, the dovetail groove 121 is first machined on a separate insert, and then the insert is fixedly installed on the first component 200 at a predetermined position. After installation, the position of the dovetail groove 121 on the insert relative to the first component 200 is fixed, and the O-ring 111 is embedded in the dovetail groove 121 on the insert. Its sealing effect is the same as that of the solution of directly creating the dovetail groove on the component body.

[0036] This embodiment is particularly suitable for scenarios where the first component 200 is a plastic injection molded part and the dovetail groove is difficult to integrally mold in the mold. Because the dovetail groove has a "narrower at the top and wider at the bottom" cross-section, direct molding on the injection molded part would require complex mold structures such as slider core pulling or forced demolding, significantly increasing mold costs and injection molding cycle. However, by machining the dovetail groove independently onto an insert, the mold structure of the first component 200 is greatly simplified, and the machining accuracy of the dovetail groove is more easily guaranteed.

[0037] In the embodiments of this application, the insert is independently manufactured by injection molding, machining, or casting, and is fixedly fitted into a pre-set mounting groove on the first component 200. Specifically, when the insert is manufactured by injection molding, the material of the insert can be the same as or different from that of the first component 200, such as engineering plastics (e.g., polypropylene, polyethylene, polyoxymethylene, polyetheretherketone, etc.). The advantage of injection molding is that it can mass-produce complex-shaped inserts at low cost, and is especially suitable for large-scale industrial production. After injection molding, the insert has a precise dovetail groove 121 cross-sectional shape.

[0038] When the insert is manufactured using machining processes, the preferred material is a metal (such as stainless steel, aluminum alloy, titanium alloy, etc.) or a high-strength engineering plastic rod. The dovetail groove 121 is machined into the insert using machining methods such as turning, milling, and wire cutting. The advantages of machining are high precision and good surface quality, making it suitable for small-batch production or applications requiring high dimensional accuracy.

[0039] When inserts are manufactured using casting, the preferred material is a metallic material (such as aluminum alloy, zinc alloy, etc.), which is integrally formed through precision casting or die casting. The advantage of casting is that it can produce inserts with complex shapes and has a high material utilization rate.

[0040] In the embodiments of this application, the insert is fixedly fitted into a preset mounting groove on the first component 200. Specifically, a mounting groove adapted to the shape of the insert is provided at a preset position on the first component 200 (such as an electrode frame). During assembly, the insert with the dovetail groove 121 is inserted into the mounting groove, and the insert is fixed to the first component 200 by means of snap connection, hot melt welding, ultrasonic welding, bonding or threaded fasteners, so that the dovetail groove 121 on the insert is flush with the sealing surface of the first component 200 or at a preset height position.

[0041] Specifically, after the insert is fixed, its top surface (i.e., the open end face of the dovetail groove) is flush with the sealing surface of the first component 200 to ensure that the O-ring 111 can make normal contact with the sealing surface of the adjacent component and produce uniform compression deformation after being inserted. If the top surface of the insert is higher or lower than the sealing surface of the first component 200, it will affect the compression amount and sealing effect of the sealing ring.

[0042] The beneficial effects of this embodiment include: firstly, it significantly reduces the mold complexity of the first component 200 (especially the plastic injection molded part), simplifies the production process, and reduces costs; secondly, the dovetail groove part can be made of a material that is more wear-resistant and has higher strength than the body of the first component 200, thereby improving the durability of the sealing structure; and thirdly, when the dovetail groove 121 wears out during use, only the insert needs to be replaced instead of the entire first component 200, reducing the later maintenance costs.

[0043] like Figure 6 and Figure 1 As shown, the fixing component 120 includes a groove 210 circumferentially disposed around the edge of the first component 200. The sealing body 110 includes a nested sealing ring 112, which includes an integrally connected sealing part 112a and a groove part 112b, the groove part 112b being fixed in the groove 210 by elastic deformation.

[0044] Specifically, the nested sealing ring 112 is integrally molded from an elastomer material (such as ethylene propylene rubber, fluororubber, perfluoroether rubber, and other corrosion-resistant elastomers), and its overall shape is ring-shaped, arranged around the area that needs to be sealed. The nested sealing ring 112 includes two functional parts: a sealing part 112a and a groove part 112b.

[0045] In the embodiments of this application, the slot portion 112b is the fixing part of the nested sealing ring 112, and its cross-section is U-shaped or C-shaped, forming a slot 210 structure. The opening width of the slot 210 structure is slightly smaller than the edge thickness of the first component 200 (electrode frame). Relying on the elastic recovery force of the elastomer material itself, the slot portion 112b can be firmly clamped on the edge of the first component 200, thereby fixing the entire nested sealing ring 112 to the first component 200. The inner surface of the slot portion 112b may also be provided with anti-slip textures or protrusions to enhance the friction between it and the first component 200 and prevent the nested sealing ring 112 from slipping in the axial direction (i.e., the stacking direction).

[0046] In the embodiments of this application, the sealing portion 112a is the sealing functional part of the nested sealing ring 112, which extends outward from the slot portion 112b (i.e., extends away from the edge of the first component 200) for use with the second component 300 (e.g., when stacked) during assembly. Figure 7 The sealing surface of the bipolar plate (shown) contacts and undergoes compressive deformation to achieve a seal. The direction in which the sealing part 112a extends from the slot part 112b depends on the specific sealing position: when used for sealing the electrolyte distribution through hole at the edge of the bipolar plate, the sealing part 112a extends outward around the through hole; when used for sealing the edge of the electrode frame, the sealing part 112a extends inward or outward along the surface of the electrode frame.

[0047] The nested sealing ring 112 of this embodiment has a simple structure and is easy to install. It does not require opening a complex sealing groove on the first component 200. It can be fixed by simply using the existing edge of the first component 200. It is especially suitable for sealing thin bipolar plates.

[0048] In the embodiments of this application, the hardness of the positioning guide 130 is greater than the hardness of the sealing body 110. Specifically, the positioning guide 130 is made of a hard material, which has a higher hardness than the elastomeric material used for sealing.

[0049] In one embodiment, the positioning guide 130 may be made of a metallic material (such as stainless steel SUS304, SUS316, aluminum alloy 6061, etc.), with a hardness typically between HV150 and HV500. In another embodiment, the positioning guide 130 may be made of a high-strength engineering plastic (such as polyetheretherketone PEEK, polyoxymethylene POM, reinforced nylon, etc.), with a Rockwell hardness typically between R100 and R120. The positioning guide 130 may also be made of ceramic materials (such as alumina, silicon nitride, etc.) to obtain higher hardness and wear resistance.

[0050] In the embodiments of this application, the sealing body 110 (including O-ring or nested sealing ring) is made of elastomeric material (such as EPDM rubber, FKM fluororubber, FFKM perfluoroether rubber, etc.), and its hardness is usually between 60 and 90 degrees Shore A hardness, which is much lower than the hardness of the positioning guide 130 when converted according to Rockwell hardness.

[0051] In the embodiments of this application, the significant difference in hardness between the positioning guide 130 and the sealing body 110 ensures the optimized performance of their respective functions: the rigid positioning guide 130 can provide reliable forced correction force during stacking and is not easily deformed or worn during repeated assembly, maintaining positioning accuracy over a long period; while the elastic sealing body 110 can generate uniform elastic deformation after being compressed to fill microscopic defects on the sealing surface, achieving a reliable seal. The difference in their material properties ensures that their respective functions do not interfere with each other and complement each other.

[0052] Furthermore, the fact that the hardness of the positioning guide 130 is greater than that of the sealing body 110 facilitates a smooth assembly process: during the process of the positioning guide 130 guiding the assembly to correct its position, the sealing body 110 has not yet been subjected to a large clamping force, and will not be affected by premature deformation due to pressure, thus ensuring positioning accuracy. After positioning is completed, the sealing body 110 undergoes elastic deformation under the clamping force, while the positioning guide 130 maintains its shape, providing a stable positioning reference for the assembly.

[0053] In the embodiments of this application, at least two positioning guides 130 and positioning mating parts 140 are respectively provided on the first component 200 and the second component 300. The positioning guides 130 are arranged diagonally on the edge area of ​​the first component 200, and the positioning mating parts 140 are provided in a one-to-one correspondence with the positioning guides 130.

[0054] Specifically, two positioning guides 130 (positioning guide pins) are respectively provided at a set of diagonal positions (such as the upper left and lower right corners) of the electrode frame (first component 200). Two positioning mating parts 140 (positioning mating holes) are respectively provided at corresponding diagonal positions of adjacent components 400 (second component 300). The line connecting the positions of the two positioning guide pins corresponds to the line connecting the positions of the two positioning mating holes in space. When the first component 200 and the second component 300 are stacked, each positioning guide pin is inserted into the corresponding positioning mating hole.

[0055] In the embodiments of this application, the core purpose of employing at least two positioning guides 130 arranged diagonally is to achieve complete positioning in the horizontal plane. Specifically, when a component is provided with two positioning guides 130, the two positioning guides 130 respectively constrain the component's degrees of freedom in two orthogonal directions in the plane. When the two positioning guides 130 are located at the upper left corner and the lower right corner respectively, the line connecting them has components in both the horizontal and vertical directions, thereby simultaneously limiting the component's displacement in both the horizontal and vertical directions and preventing the component's rotational degrees of freedom in the plane.

[0056] If only one positioning guide 130 is set, only the translational degree of freedom of the component in the plane can be constrained, but the rotational degree of freedom of the component about the axis of the positioning guide cannot be constrained, and the component may still be misaligned by rotation. Only by setting two or more positioning guides 130 and arranging them diagonally can the complete positioning of the component be achieved.

[0057] In large fuel cell stacks, four or more positioning guides 130 can be set on each component (such as one at each of the four corners) to further improve positioning accuracy and assembly stability. However, at least two diagonally arranged guides are sufficient to meet basic positioning requirements and represent the optimal balance between cost and performance.

[0058] The positioning guide 130 is located in the edge region of the assembly rather than the central region to avoid the central flow channel region and electrode region, thus preventing interference with the internal fluid distribution and electrochemical performance of the fuel cell stack. In addition, the edge region has more space, which facilitates the arrangement and fabrication of the positioning guide 130.

[0059] On the other hand, embodiments of this application provide a flow battery stack, including multiple electrode frames and multiple bipolar plates stacked alternately. A sealing and positioning structure 100 is provided between adjacent electrode frames and bipolar plates, and / or between two adjacent electrode frames. One of the electrode frames and the bipolar plates is a first component, and the other is a second component. Figure 1 As shown.

[0060] Specifically, the assembly process of the fuel cell stack is as follows: like Figure 1 As shown, the electrode frame is first placed horizontally on the assembly platform. The electrode frame is equipped with a positioning guide 130 (positioning guide pin) and a sealing body 110 fixed by a fixing assembly 120 (dovetail groove 121 or slot 210). A sealing structure consisting of a dovetail groove 121 and an O-ring 111 is provided around the flow channel area in the center of the electrode frame. The flow channel area is used to accommodate the flow of the electrode and electrolyte.

[0061] Then place the bipolar plate on top of the electrode frame. The operator only needs to roughly align the positioning mating part 140 (positioning mating hole) on the bipolar plate with the positioning guide pin on the electrode frame; precise visual alignment is not required.

[0062] Then, a downward pressure is applied to the bipolar plates along the stacking direction A. For example... Figure 3 As shown, the tapered guide end 131 of the positioning guide pin first enters the positioning mating hole, automatically correcting the positional deviation in the XY plane. As pressure is continuously applied, the bipolar plate slides precisely down the axial direction of the positioning guide pin until its sealing surface contacts the O-ring 111 embedded in the dovetail groove 121 of the electrode frame. Further pressurization to the predetermined pressure causes the O-ring 111 to undergo uniform elastic deformation, achieving a reliable seal.

[0063] like Figure 6 and Figure 7 As shown, a nested sealing ring 112 is also provided at the electrolyte distribution through hole at the edge of the bipolar plate. The nested sealing ring 112 is fixed to the edge of the bipolar plate by its slot portion 112b, and the continuous ridges on its sealing portion 112a are pressed against the sealing surface of the adjacent electrode frame to form a labyrinth sealing structure, thereby sealing the electrolyte distribution through hole.

[0064] Following the steps described above, all the single-cell modules are stacked sequentially, that is, bipolar plates are placed on each electrode frame, the next electrode frame, the next bipolar plate, and so on, until the predetermined number of single cells is reached. Finally, a uniform fastening force is applied to the entire stack through the end plates and fastening bolts to complete the stack assembly.

[0065] In the embodiments of this application, an annular flow channel sealing area is provided on the electrode frame, and the sealing body 110 (O-ring 111) is arranged around the flow channel sealing area. The positioning guide 130 (positioning guide pin) and the positioning mating part 140 (positioning mating hole) are arranged in the non-flow channel area of ​​the electrode frame (such as corners, near bolt holes) to avoid interfering with the flow of electrolyte.

[0066] An electrolyte distribution through hole is provided on the edge of the bipolar plate. The sealing body 110 (the sealing part 112a of the nested sealing ring 112) is arranged around the electrolyte distribution through hole and is nested and fixed to the edge of the bipolar plate through its slot part 112b.

[0067] In an alternative embodiment, the positioning guide 130 can also be disposed on the bipolar plate, while the positioning mating part 140 is disposed on the electrode frame. That is, the positions of the positioning guide and the positioning mating part can be interchanged, as long as they can cooperate and guide each other during the stacking process. In this case, the first component 200 is the bipolar plate, and the second component 300 is the electrode frame.

[0068] In another alternative, when a sealing positioning structure 100 is provided between two electrode frames (i.e., no bipolar plate is provided in the middle), the first component 200 is one electrode frame, the second component 300 is the other adjacent electrode frame, and the sealing body 110 is arranged around the sealing interface between the two electrode frames. The positioning guide 130 is provided on one of the electrode frames, and the positioning mating component 140 is provided on the other electrode frame, and the two cooperate to guide each other when stacked.

[0069] In the embodiments of this application, the sealing and positioning structures 100 on each component are independent of each other, each completing the sealing and positioning between adjacent layers. However, the positioning of the entire fuel cell stack is achieved by the cooperation of all positioning guides and positioning mating parts. Since the positioning of each layer is carried out independently, the cumulative positioning error can be controlled within a very small range, ensuring the assembly accuracy of the entire fuel cell stack.

[0070] The sealing and positioning structure 100 of the flow battery stack and the flow battery stack of this application can realize automatic guidance and precise positioning of components during the stacking process, while providing reliable sealing, simplifying the assembly process, improving production efficiency and product reliability, and are suitable for mass production of large-scale, long-term flow battery energy storage systems, with broad industrial application prospects.

[0071] The above provides a detailed description of a sealing and positioning structure for a flow battery stack and the flow battery stack as described in the embodiments of this application. The description of the above embodiments is only for the purpose of helping to understand the core idea of ​​this application, and the above description should not be construed as including a limitation on the scope of protection of this application.

Claims

1. A sealed positioning structure for a flow battery stack, characterized in that, include: A sealing body is disposed on the first component; A fixing component, disposed on the first component, is used to fix the sealing body; A positioning guide is disposed on the first component; as well as A positioning and mating component is disposed on a second component, which is disposed adjacent to the first component, and the positioning and mating component cooperates with the positioning guide component; The fixing component includes a dovetail groove, the opening width of which is smaller than the bottom width, and the bottom of the dovetail groove is connected to the groove wall by a circular arc transition. The sealing body includes an O-ring, which is fitted into the dovetail groove; During the stacking process, the positioning guide and the positioning mating part guide the first component and the second component to be aligned to a predetermined relative position, and cause the sealing body to be pressed against the sealing interface between the first component and the second component at the predetermined relative position.

2. The sealing and positioning structure of the flow battery stack according to claim 1, characterized in that, The positioning guide includes at least one of a guide pin, a guide block, or a guide boss, and the positioning guide has a tapered surface or an arc surface for guiding the mating. The positioning fitting component includes at least one of a guide hole, a guide groove, or a guide recess, and the shape of the positioning fitting component is adapted to the shape of the positioning guide component.

3. The sealing and positioning structure of the flow battery stack according to claim 1, characterized in that, The dovetail groove is independently formed on an insert, and the insert is separately set from the first component and fixedly installed on the first component.

4. The sealing and positioning structure of the flow battery stack according to claim 3, characterized in that, The insert is independently manufactured by injection molding, machining or casting processes and is fixedly fitted into a pre-set mounting groove on the first component.

5. The sealing and positioning structure of the flow battery stack according to claim 1, characterized in that, The fixing component includes a groove circumferentially disposed around the edge of the first component, and the sealing body includes a nested sealing ring. The nested sealing ring includes an integrally connected sealing part and a groove part, and the groove part is fixed in the groove by elastic deformation.

6. The sealing and positioning structure of the flow battery stack according to claim 5, characterized in that, The sealing part has continuous ridges, which together with the sealing surface of the second component form a labyrinth seal structure after compression.

7. The sealing and positioning structure of the flow battery stack according to claim 1, characterized in that, The hardness of the positioning guide is greater than the hardness of the sealing body.

8. The sealing and positioning structure of the flow battery stack according to claim 1, characterized in that, The first component and the second component are respectively provided with at least two positioning guides and positioning mating parts. The positioning guides are arranged diagonally on the edge area of ​​the first component, and the positioning mating parts are provided in one-to-one correspondence with the positioning guides.

9. A flow battery stack, characterized in that, include: Multiple electrode frames and multiple bipolar plates are stacked alternately; Wherein, a sealing positioning structure as described in any one of claims 1 to 8 is provided between adjacent electrode frames and bipolar plates, and / or between two adjacent electrode frames, wherein one of the electrode frames and the bipolar plates is the first component and the other is the second component.

Images