Liquid flow battery assembly and electric pile

Abstract

The invention discloses a liquid flow battery assembly and an electric pile. The liquid flow battery assembly is an integral assembly formed by sequentially and fixedly overlapping a flow channel frame body, a bipolar plate and a bottom plate frame body; the runner frame body is a plate-shaped frame body with a first through hole in the middle area and is provided with a through hole A, a groove is formed in a first face frame plate of the runner frame body, and a through hole B is formed in the bipolar plate; the bottom plate frame body is a plate-shaped frame body with a second through hole in the middle area, and a through hole C is formed in the bottom plate frame body; the first through hole and the second through hole are correspondingly the same or similar in size and position; the plate surface of the first through hole of the runner frame body is fixedly connected with the first panel of the bipolar plate; the second surface of the bipolar plate is fixedly connected with the plate surface of the second through hole of the bottom plate frame body, and after the runner frame body, the bipolar plate and the bottom plate frame body are sequentially overlapped, the through hole A, the through hole B and the through hole C are coaxially communicated and fixedly connected for electrolyte circulation.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and particularly relates to a flow battery component and a stack. Background Art

[0002] As a flow battery electrochemical energy storage technology with the most promising development prospect and having entered the initial stage of industrialization, the all-vanadium flow battery has received extensive attention in recent years. Especially the advantages of the aqueous electrolyte such as safety, decoupling of power and capacity, long life, and deep charge and discharge are very suitable for entering the long-duration energy storage market. However, the all-vanadium flow battery also has some disadvantages of flow batteries. For example, leakage current will occur due to the relationship between the inter-cell voltage and the common pipeline in the stack and the system, and this leakage current will affect the electrolyte potential in the entire electrolyte flow path. If this electrolyte comes into contact with a carbon-containing material (such as a bipolar plate) that conducts electricity with other circuits in the non-electrode region, when the interfacial potential is higher than the reaction potential of carbon and water (about 0.207V), carbon will react with water to generate hydrogen ions and carbon dioxide, and then destructive phenomena such as bulging, fracture, and perforation will occur, damaging the bipolar plate, causing internal and external leakage of the stack, and significantly reducing the reliability of the stack. Summary of the Invention

[0003] In view of this, the present invention provides a flow battery component and a stack, and the main purpose is to solve the technical problem that the contact between the bipolar plate in the non-electrode contact area and the electrolyte will cause corrosion of carbon-containing materials such as the bipolar plate.

[0004] On the one hand, the present invention provides a flow battery component, and the flow battery component is fixedly laminated into an integral component by a flow channel frame, a bipolar plate, and a bottom plate frame in sequence;

[0005] Wherein, the flow channel frame is a plate-shaped frame with a first through hole opened in the middle area, the flow channel frame is provided with a through hole A for the electrolyte to flow through, and a groove for conveying the electrolyte into the first through hole is provided on the first surface frame plate of the flow channel frame. Opposite to the first surface frame plate is the second surface frame plate of the flow channel frame;

[0006] The bipolar plate has opposite first and second panels, and the bipolar plate is provided with a through hole B for the electrolyte to flow through;

[0007] The bottom plate frame is a plate-shaped frame with a second through hole opened in the middle area, the bottom plate frame has opposite first and second surface frame plates, and the bottom plate frame is provided with a through hole C for the electrolyte to flow through;

[0008] The sizes of the first through hole on the flow channel frame and the second through hole on the bottom plate frame are the same or similar, and the opening positions are correspondingly the same or similar;

[0009] The second face plate of the flow channel housing is superposed with the first panel of the bipolar plate, the through hole A and the through hole B are fixedly connected, and the plate surface of the first through hole and the first panel of the bipolar plate are fixedly connected;

[0010] The second surface of the bipolar plate is superposed with the first face of the bottom plate housing, the through hole B and the through hole C are fixedly connected, and the plate surface of the second through hole and the second panel of the bipolar plate are fixedly connected;

[0011] After the flow channel housing, the bipolar plate and the bottom plate housing are superposed in sequence, the through hole A, the through hole B, and the through hole C are coaxially penetrated for the electrolyte to flow through.

[0012] Optionally, the plate surface of the first through hole of the flow channel housing and the first panel of the bipolar plate are fixed into one body by laser welding.

[0013] Optionally, the plate surface of the second through hole of the bottom plate housing and the second panel of the bipolar plate are fixed into one body by laser welding.

[0014] The welding track of the plate surface of the first through hole of the present application and the first panel of the bipolar plate is a closed-loop laser welding along the plate surface near the first through hole of the flow channel housing; similarly, the plate surface near the second through hole and the second panel of the bipolar plate also perform a closed-loop laser welding.

[0015] When laser welding the flow channel housing and the bipolar plate in the present application, the welding track can be set in the groove of the flow channel housing.

[0016] Optionally, the flow battery assembly further includes an annular connector, which is an annular cylinder with a third through hole opened in the middle area, and the third through hole is for the electrolyte to flow through; an annular boss A extends axially along the annular cylinder, and the annular surface outside the outer diameter of the annular boss A on the annular cylinder is the first annular surface, and the second annular surface is opposite to the first annular surface;

[0017] The annular boss A is embedded in the through hole C, and the bottom plate housing and the annular connector are fixed into one body by laser welding on the first annular surface;

[0018] The second annular surface of the annular cylinder is embedded in the through hole B of the bipolar plate;

[0019] The through hole A and the annular cylinder are laser welded on the second annular surface, and the flow channel housing, the bipolar plate and the bottom plate housing are fixed into one body.

[0020] The above-mentioned annular boss of the present application is used for positioning. The welding surfaces are the front and back sides of the non-boss part of the annular connector. One side is welded to the bottom plate frame body, and the other side is welded to the flow channel frame body; the laser welding is planar welding, and the light-transmitting layer above is welded to the light-absorbing layer below.

[0021] Optionally, the outer diameter of the annular boss A is smaller than the outer diameter of the annular cylinder.

[0022] Optionally, the thickness of the annular cylinder of the annular connector is the same as or close to the depth of the through hole B; the thickness of the annular boss A of the annular connector is the same as or close to the depth of the through hole C.

[0023] Optionally, the outer diameter of the annular cylinder is less than or equal to the inner diameter of the through hole B; the outer diameter of the annular boss A is less than or equal to the inner diameter of the through hole C; the inner diameter of the through hole A is smaller than the outer diameter of the annular cylinder.

[0024] Optionally, an annular boss B extends axially outward along the through hole C, and a fourth through hole is provided in the middle of the annular boss B; the inner diameter of the through hole A is smaller than the outer diameter of the annular boss B; the inner diameter of the through hole C is smaller than the outer diameter of the annular boss B.

[0025] Optionally, the annular boss B is embedded into the through hole B, and the through hole A and the annular boss B are fixed as a whole by laser welding on the annular surface.

[0026] Optionally, the shapes of the first through hole, the second through hole and the bipolar plate are all the same, and the shape is selected from square, circular or oval;

[0027] The number of the through holes A is at least 4 (generally 4 to 20), and they are at least respectively arranged at the four corners of the flow channel frame body. The size of the first through hole is greater than or equal to the size of the electrode, and is used for installing the electrode; the number of the above through holes A can be set according to actual needs.

[0028] Optionally, the 4 through holes A include a positive electrode electrolyte inlet, a positive electrode electrolyte outlet, a negative electrode electrolyte inlet and a negative electrode electrolyte outlet; the groove includes a groove A and a groove B. The groove A communicates the electrolyte inlet and the first through hole, and the groove B communicates the electrode liquid outlet and the first through hole.

[0029] Optionally, the number of the through holes B is 4, and they are respectively arranged at the four corners of the bipolar plate.

[0030] Optionally, the number of the through holes C is 4, and they are respectively arranged at the four corners of the bottom plate frame body. The size of the second through hole is greater than or equal to the size of the electrode.

[0031] Optionally, the annular connector is made of a light-absorbing material, or light-absorbing agents for absorbing near-infrared light are coated on two surfaces of the annular connector.

[0032] Optionally, the materials of the flow channel frame, the bottom plate frame, and the annular connector are all high molecular polymers; the high molecular polymer materials include polypropylene and polyethylene.

[0033] Optionally, the materials of the flow channel frame and the bottom plate frame are both high molecular polymer materials with a light transmittance of greater than or equal to 20%.

[0034] Optionally, the material of the panel of the bipolar plate is a carbon-plastic composite material.

[0035] Optionally, the flow channel frame includes an electrode frame.

[0036] In a second aspect, the present invention provides a method for preparing the above-mentioned flow battery assembly, and the method includes the following steps:

[0037] S1: Stack the flow channel frame, the bipolar plate, and the bottom plate frame in sequence, and place the through hole A, the through hole B, and the through hole C in alignment in sequence;

[0038] S2: Fix the through hole A and the through hole C into one body by laser welding;

[0039] S3: Perform closed-loop laser welding along the plate surface of the first through hole of the flow channel frame and the first panel of the bipolar plate to fix the flow channel frame and the first panel of the bipolar plate into one body;

[0040] S4: Perform closed-loop laser welding along the plate surface of the second through hole of the bottom plate frame and the second panel of the bipolar plate to fix the bottom plate frame and the second panel of the bipolar plate into one body.

[0041] Optionally, step S1 includes: horizontally placing the bipolar plate on a special device for positioning, placing the annular connector in the through hole B of the bipolar plate, and coaxially sleeving the through hole C of the bottom plate frame outside the annular boss A of the annular connector.

[0042] Optionally, step S2 includes: performing closed-loop laser welding on the second ring surface of the annular connector to fix the annular connector and the through hole A into one body;

[0043] Performing closed-loop laser welding on the first ring surface of the annular connector to fix the annular connector and the through hole C into one body.

[0044] Optionally, step S2 includes: horizontally placing the bipolar plate on a dedicated device for positioning, sleeving the annular boss B provided in the through-hole C of the bottom plate frame into the through-hole B of the bipolar plate, then stacking the second surface of the flow channel frame on the first surface of the bipolar plate, aligning the positions of the through-hole B and the through-hole A, and performing closed-loop laser welding on the annular surface of the annular boss B to fix the annular boss B and the through-hole A as a whole.

[0045] This application provides a specific welding process: First, weld the annular cylinder and the bottom plate frame into a whole. The welding process is as follows: The boss side of the annular cylinder faces the bottom plate frame, and the height of the boss is the same as the thickness of the bottom plate frame. The diameter of the through-hole of the bottom plate frame is slightly larger than the outer edge of the boss of the annular cylinder, so that they can be sleeved together. On the outer side of the boss, a ring-shaped welding wire is provided at the overlapping part of the bottom plate and the cylinder to weld the annular cylinder and the bottom plate together. All four annular cylinders are welded in this way. Then place this welded component on the bipolar plate, and the annular cylinder and the through-hole of the bipolar plate are coaxially installed. The thickness of the bipolar plate is the same as the thickness of the non-boss part of the annular cylinder. After placement, a closed-loop welding wire is provided at the edge of the large-area hollow in the center of the bottom plate frame to weld the bottom plate frame and the bipolar plate together. Then place the flow channel frame on the bipolar plate, and a closed-loop welding wire is provided at the edge of the large-area hollow in the center to weld the flow channel frame and the bipolar plate together. At the same time, a welding wire is provided at the outer edge of the flow port of the flow channel frame, that is, on the side opposite to the boss of the annular cylinder, and welded together. That is, the non-boss area on the side of the boss of the annular cylinder is welded to the bottom plate frame; while the side opposite to the boss is welded to the flow channel frame. The advantages of this are: The flow channel through-hole of the bipolar plate will not contact the electrolyte, avoiding electrochemical corrosion of the bipolar plate at this position. At the same time, the periphery of the large-area hollow area in the center of the bottom plate and the flow channel frame is welded to the bipolar plate, and the electrolyte in this area will not flow into other areas of the bipolar plate. The purpose of the whole structure is: The area of the bipolar plate in contact with the electrolyte is only the area in contact with the electrode, and other positions do not contact the electrolyte, preventing corrosion of the bipolar plate.

[0046] In a third aspect, the present invention provides a flow battery stack, including a battery stack assembly; the battery stack assembly includes the above-mentioned flow battery assembly.

[0047] In a fourth aspect, the present invention provides an energy storage system, including a flow battery stack; the flow battery stack includes the above-mentioned flow battery stack.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] Through the working effects of the structure and process, the present invention isolates the electrolyte in the stack from the non-electrode contact area in the bipolar plate, avoiding the carbon corrosion reaction that occurs when the interphase potential is higher than the reaction potential of carbon and water in the bipolar plate under charge and discharge conditions. This structure can significantly improve the reliability of the stack, especially when the polarization increases and the voltage efficiency is low after the stack has been operating for a long time. According to the experimental results, the bipolar plate at the above-mentioned flow channel hole position of the stack without this structure is corroded and leaked within about 100 cycles; it is corroded and leaked at about 700 cycles on the bipolar plate plane. However, with the welding assembly of the present invention, no obvious internal or external leakage is found when the stack operates for 2000 cycles. After disassembling the stack, the bipolar plate is in good condition without corrosion marks. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a schematic exploded view of a flow battery stack assembly provided by an embodiment of the present application;

[0051] Figure 2 is a schematic structural view of a flow channel frame in the assembly provided by an embodiment of the present application;

[0052] Figure 3 is a schematic structural view of a bipolar plate in the assembly provided by an embodiment of the present application;

[0053] Figure 4 is a schematic structural view of an annular connecting piece in the assembly provided by an embodiment of the present application;

[0054] Figure 5 is a schematic structural view of a bottom plate frame in the assembly provided by an embodiment of the present application;

[0055] Figure 6 is a schematic diagram of the welding relationship and welding path among the bipolar plate, the annular connecting piece and the bottom plate frame provided by an embodiment of the present application;

[0056] Figure 7 is a schematic diagram of the welding relationship and welding path between the flow channel frame and Assembly A provided by an embodiment of the present application;

[0057] Figure 8 is a schematic structural view of a bottom plate frame with an annular boss provided in a through hole C provided by an embodiment of the present application;

[0058] Figure 9 is a physical diagram of a welding assembly of a bottom plate and a bipolar plate provided by an embodiment of the present application;

[0059] Figure 10 is a physical diagram of a welding assembly of a flow channel frame and a bipolar plate provided by an embodiment of the present application;

[0060] Figure 11 is a physical diagram of the annular connecting piece provided by an embodiment of the present application.

[0061] Reference numerals:

[0062] 1 - Flow channel housing, 11 - Through hole A, 12 - Groove A, 13 - Groove B, 14 - First through hole;

[0063] 2 - Bipolar plate, 21 - Through hole B;

[0064] 3 - Ring-shaped connecting piece, 31 - Ring-shaped cylinder, 32 - Ring-shaped boss A, 33 - Third through hole;

[0065] 4 - Bottom plate housing, 41 - Through hole C, 42 - Second through hole, 43 - Ring-shaped boss B;

[0066] 5 - Closed-loop welding path between the hole wall of the second through hole and the second panel of the bipolar plate;

[0067] 6 - Closed-loop welding path between through hole B and through hole C;

[0068] 7 - Closed-loop welding path between the hole wall of the first through hole and the first panel of the bipolar plate;

[0069] 8 - Closed-loop welding path between through hole A and through hole B;

[0070] 9 - New bottom plate housing. Detailed implementation mode

[0071] The following further elaborates on this application in combination with specific embodiments. The following description is only several embodiments of this application and does not impose any form of limitation on this application. Although this application is disclosed below with preferred embodiments, it is not used to limit this application. Any person skilled in the relevant art, without departing from the scope of the technical solution of this application, making some changes or modifications using the technical content disclosed above is equivalent to equivalent implementation cases and all fall within the scope of the technical solution.

[0072] Unless otherwise specified, the raw materials in the embodiments of this application are purchased through commercial channels and used directly without any special treatment.

[0073] Embodiment 1

[0074] An assembly structure of a flow battery welding component is as Figure 1 shown;

[0075] The above-mentioned welding component is composed of a flow channel housing 1, a bipolar plate 2, and a bottom plate housing 4, which are sequentially fixed and stacked into an integral component by a ring-shaped connecting piece 3; the detailed drawings of the four components are respectively as Figure 2 , 3 , 4 and 5 shown;

[0076] As Figure 2As shown, the flow channel housing 1 is a flat plate. The central area of the flat plate is a hollow structure (i.e., the first through hole), and there are concave platforms around the hollow structure; there are four through holes A at the four corners of the flow channel housing 1, namely the positive electrolyte inlet through hole, the positive electrolyte outlet through hole, the negative electrolyte inlet through hole, and the negative electrolyte outlet through hole; a groove A communicating the positive electrolyte inlet through hole with the hollow structure is provided on the flow channel housing 1, and a groove B communicating the positive electrolyte outlet with the hollow structure is provided; alternatively, a groove A communicating the negative electrolyte inlet through hole with the hollow structure is provided on the flow channel housing 1, and a groove B communicating the negative electrolyte outlet with the hollow structure is provided.

[0077] As Figure 3 shown, the bipolar plate 2 is in the shape of a flat plate, and there are through holes B provided thereon corresponding to the positions of the through holes A of the flow channel housing. The bipolar plate 2 has opposite first and second panels, and the bipolar plate 2 is made of a black carbon plastic composite material.

[0078] As Figure 4 shown, the annular connector 3 is an annular cylinder 31 with a hollow center (i.e., a third through hole 33 is opened in the middle area). The thickness of the annular cylinder 31 is equal to the thickness of the bipolar plate 2; an annular boss 32 is provided on one surface of the annular cylinder perpendicular to the axis (i.e., an annular boss A32 extends axially outward along the first annular surface of the annular cylinder 31, and the second annular surface is opposite to the first annular surface). The outer diameter of the annular boss A is smaller than the outer diameter of the annular cylinder 31; the annular connector 3 has the ability to absorb near-infrared light, and its body is a high light absorber or is coated with a light absorber that absorbs near-infrared light.

[0079] As Figure 5 shown, the bottom plate housing 4 is a flat plate, and there are through holes C provided thereon corresponding to the positions of the through holes A of the flow channel housing 1, and a corresponding hollow structure (i.e., the second through hole 42) is provided on the bottom plate housing 4; the above-mentioned flow channel housing 1 and bottom plate housing 4 are plastics with a light transmittance of not less than 20%.

[0080] The flow channel housing 1, the annular connector 3, and the bottom plate housing 4 are made of the same material of PE or PP, and the material of the panels of the bipolar plate 2 is a carbon plastic composite material.

[0081] As Figure 6As shown, the second annular surface of the annular connector 3 is embedded into the through-hole B of the bipolar plate 2, and the annular boss A on the first annular surface is embedded into the through-hole C; the through-hole C and the through-hole B are fixed together by laser welding on the above-mentioned first annular surface, and the closed-loop welding path is as shown in 6 (the welding path falls on the plate surface near the through-hole C of the bottom plate frame and the first annular surface of the annular connector, not the table surface of the annular boss A); a part of the plate surface near the second through-hole 42 of the bottom plate frame 4 and the second panel of the bipolar plate 2 are fixed together by laser welding, and the closed-loop welding path is as shown in 5 (the welding path falls on the plate surface of the bottom plate frame).

[0082] As Figure 7 As shown, the through-hole A and the annular connector are fixed together by laser welding on their second annular surfaces (the inner diameter of the through-hole A is smaller than the outer diameter of the annular connector, and the laser falls near the circumference of the through-hole A of the flow channel frame), and the closed-loop welding path is as shown in 8; the plate surface of the first through-hole 14 of the flow channel frame 1 and the first panel of the bipolar plate 2 are fixed together by laser welding, and the closed-loop welding path is as shown in 7 (the welding path falls in the groove on the plate surface near the first through-hole 14); after the flow channel frame 1, the bipolar plate 2, and the bottom plate frame 4 are stacked and fixed in sequence, the through-hole A, the through-hole B, and the through-hole C are coaxially penetrated for the electrolyte to flow through.

[0083] The welding process of the above-mentioned flow battery welding assembly is as follows: Place 2 horizontally on a special fixture for positioning, and place four 3 horizontally in the flow channel holes on 2 for positioning and installation; the side of 3 with the annular boss is placed horizontally upward; the inner diameter of the flow channel hole of 2 is not less than the outer diameter of the cylinder of 3; Place 4 horizontally above 2, and the flow channel holes provided on 4 are coaxially sleeved outside the annular boss of 3; the inner diameter of the flow channel hole of 4 is not less than the outer diameter of the annular boss of 3 and the thickness is the same as that of 4; the laser welding path after the assembly of 2, 3, and 4 is as Figure 6 shown; Set a closed-loop welding path 5 around the central hollow structure of 4, and weld 2 and 4 together by laser welding; Set a closed-loop welding path 6 around the four flow channel holes of 4, and weld the plane between the annular boss of 4 and the outer ring of the cylinder of 3 together; The assembly of welding 2, 3, and 4 together is called assembly A; The bipolar plate side of assembly A is horizontally positioned upward on a special fixture, and 1 is fixedly positioned above assembly A; the flow channel holes of 1 and assembly A correspond to each other. The side of 1 with the groove is placed upward. The welding path set on 1 is as Figure 7 shown; Among them, set a closed-loop welding path 7 on the concave platform around the hollow structure of 1, and weld 1 and the bipolar plate of assembly A together by laser welding; Set a closed-loop welding path 8 around the four through-holes of 1, and weld it to the plane on one side of the cylinder perpendicular to the axis of 3.

[0084] After the above welding is completed, the electrolyte is completely isolated from the non-electrode contact area of the bipolar plate through the set closed-loop welding line. Only the electrodes placed in the central hollow areas of 1 and 4 are in contact with the bipolar plate; thus, the carbon corrosion reaction that occurs after the non-electrode contact area comes into contact with the electrolyte is eliminated, and the damage to the bipolar plate is avoided. The 30kW stack assembled with the above welding assembly consists of 120 cells. After 1000 cycles, the bipolar plate is still intact, and there are no phenomena such as bulging or damage on the surface of the bipolar plate. The stack efficiency is stable and there is basically no attenuation.

[0085] Example 2

[0086] A welding assembly for a flow battery stack, which is different from the welding assembly of Embodiment 1 in that the annular connecting ring 3 is cancelled; an annular boss B is provided around the through hole C on the bottom plate frame 4 (that is, an annular boss B extends axially outward along the through hole C, and a fourth through hole is opened in the middle of the annular boss B). The outer diameter of the annular boss B is larger than the inner diameter of the through hole C, forming a new bottom plate frame 9, as Figure 8 shown; the thickness of the annular boss B is the same as the thickness of the bipolar plate 2, and the outer diameter of the annular boss B is not larger than the aperture of the through hole B of the bipolar plate 2; the annular boss B is embedded in the through hole B, and the through hole A and the annular boss B are fixed into one body by laser welding on their annular table surfaces (that is, by setting laser welding paths around the through hole A of the corresponding flow channel frame 1 and on the annular table surface of the annular boss B, the flow channel frame 1 and the bottom plate frame 4 are fixed into one body).

[0087] After cancelling the annular connecting piece 3, the welding process is as follows: Place the new bottom plate frame 9 horizontally on a special fixture for positioning, and place the side with the annular boss B facing up horizontally; Place the bipolar plate 2 horizontally above the bottom plate frame 9, and the through hole B provided on the bipolar plate 2 is coaxially sleeved outside the annular boss B of the bottom plate frame 9; The laser welding path after the bipolar plate 2 and the bottom plate frame 9 are assembled is also as Figure 6 shown; A closed-loop welding path 5 is provided around the central hollow structure of the bottom plate frame 9, and the bipolar plate 2 and the bottom plate frame 9 are welded into one body by laser welding process; The assembly of welding 2 and 9 into one body is called Assembly B; The bipolar plate side of Assembly B is positioned horizontally upward on a special fixture, and the flow channel frame 1 is positioned at the same position above Assembly B; The through hole positions of the flow channel frame 1 and Assembly B correspond to each other; The side of the flow channel frame 1 with the groove faces up; The welding path provided on the flow channel frame 1 is also as Figure 7As shown in the figure; among them, a closed-loop welding path 7 is set on the concave platform around the hollow structure of the flow channel housing 1, and the flow channel housing 1 and the bipolar plate of component B are welded into one body by a laser welding process; a closed-loop welding path 8 is set around the four through holes A of the flow channel housing 1 and welded to the tabletop of the annular boss B embedded in the through hole B of the bipolar plate 2; an absorbent for absorbing near-infrared light should be coated on the surface of the annular boss B of the bottom plate housing 9 to facilitate the laser welding of the two light-transmitting materials of the flow channel housing 1 and the bottom plate housing 9.

[0088] The above are only several embodiments of the present application and do not impose any form of limitation on the present application. Although the present application is disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to equivalent implementation cases and all belong to the scope of the technical solution.

Claims

1. A flow battery component, characterized in that, the flow battery component is formed by sequentially and fixedly laminating a flow channel frame, a bipolar plate, and a bottom plate frame into an integral component; wherein, the flow channel frame is a plate-shaped frame with a first through hole opened in the middle region, the flow channel frame is provided with a through hole A for the electrolyte to flow through, and a groove for delivering the electrolyte into the first through hole is provided on the first face frame plate of the flow channel frame. Opposite to the first face frame plate is the second face frame plate of the flow channel frame; the bipolar plate has opposite first and second panels, and the bipolar plate is provided with a through hole B for the electrolyte to flow through; the bottom plate frame is a plate-shaped frame with a second through hole opened in the middle region, the bottom plate frame has opposite first and second face frame plates, and the bottom plate frame is provided with a through hole C for the electrolyte to flow through; the sizes of the first through hole on the flow channel frame and the second through hole on the bottom plate frame are the same or similar, and the opening positions are correspondingly the same or similar; the second face frame plate of the flow channel frame is laminated with the first panel of the bipolar plate, and the plate surface of the first through hole is fixedly connected to the first panel of the bipolar plate; the second surface of the bipolar plate is laminated with the first face of the bottom plate frame, and the plate surface of the second through hole is fixedly connected to the second panel of the bipolar plate; after the flow channel frame, the bipolar plate, and the bottom plate frame are sequentially laminated, the through hole A, the through hole B, and the through hole C are coaxially penetrated and fixedly connected for the electrolyte to flow through.

2. The flow battery component according to claim 1, characterized in that, the plate surface of the first through hole of the flow channel frame and the first panel of the bipolar plate are fixed into one body by laser welding; preferably, the plate surface of the second through hole of the bottom plate frame and the second panel of the bipolar plate are fixed into one body by laser welding.

3. The flow battery component according to claim 1, characterized in that, the flow battery component further includes an annular connecting piece, which is an annular cylinder with a third through hole opened in the middle region, and the third through hole is used for the electrolyte to flow through; an annular boss A extends axially along the annular cylinder, and the annular surface of the annular cylinder outside the outer diameter of the annular boss A is the first annular surface, and opposite to the first annular surface is the second annular surface; the annular boss A is embedded in the through hole C, and the bottom plate frame and the annular connecting piece are fixed into one body by laser welding on the first annular surface; the second annular surface of the annular cylinder is embedded in the through hole B of the bipolar plate; the through hole A and the annular cylinder are fixed into one body by laser welding on the second annular surface, and the flow channel frame, the bipolar plate, and the bottom plate frame are fixed into one body; preferably, the outer diameter of the annular boss is smaller than the outer diameter of the annular cylinder; preferably, the thickness of the annular cylinder of the annular connecting piece is the same as the depth of the through hole B; the thickness of the annular boss A of the annular connecting piece is the same as the depth of the through hole C; Preferably, the outer diameter of the annular cylinder is less than or equal to the inner diameter of the through hole B; the outer diameter of the annular boss A is less than or equal to the inner diameter of the through hole C; the inner diameter of the through hole A is less than the outer diameter of the annular cylinder.

4. A flow battery assembly according to claim 1, wherein, an annular boss B extends axially outward along the through hole C, and a fourth through hole is formed in the middle of the annular boss B; the inner diameter of the through hole A is less than the outer diameter of the annular boss B; the inner diameter of the through hole C is less than the outer diameter of the annular boss B; Preferably, the annular boss B is embedded in the through hole B, and the through hole A and the annular boss B are fixed into one body by laser welding on the annular surface; Preferably, the shapes of the first through hole, the second through hole and the bipolar plate are the same, and the shape is selected from square, circular or oval; The number of the through holes A is at least 4, and they are respectively arranged at four corners of the flow channel frame body at least, and the size of the first through hole is greater than or equal to the size of the electrode for installing the electrode; Preferably, the 4 through holes A include a positive electrolyte inlet, a positive electrolyte outlet, a negative electrolyte inlet and a negative electrolyte outlet; the groove includes a groove A and a groove B, the groove A communicates the electrolyte inlet and the first through hole, and the groove B communicates the electrode liquid outlet and the first through hole; Preferably, the number of the through holes B is 4, and they are respectively arranged at four corners of the bipolar plate; Preferably, the number of the through holes C is 4, and they are respectively arranged at four corners of the bottom plate frame body, and the size of the second through hole is greater than or equal to the size of the electrode.

5. A flow battery assembly according to claim 3, wherein, the annular connecting piece is made of a light-absorbing material, or light-absorbing agents for absorbing near-infrared light are coated on two surfaces of the annular connecting piece; Preferably, the materials of the flow channel frame body, the bottom plate frame body and the annular connecting piece are all high molecular polymers; the high molecular polymer materials include polypropylene and polyethylene; Preferably, the materials of the flow channel frame body and the bottom plate frame body are all high molecular polymer materials with a light transmittance greater than or equal to 20%; Preferably, the material of the panel of the bipolar plate is a carbon plastic composite material; Preferably, the flow channel frame body includes an electrode frame.

6. A method for preparing the flow battery assembly according to any one of claims 1 to 5, wherein, the method includes the following steps: S1: Stack the flow channel frame body, the bipolar plate and the bottom plate frame body in sequence, and align the through hole A, the through hole B and the through hole C in sequence; S2: Fix the through hole A and the through hole C into one body by laser welding; S3: Perform closed-loop laser welding along the plate surface of the first through hole of the flow channel frame body and the first panel of the bipolar plate to fix the flow channel frame body and the first panel of the bipolar plate into one body; S4: Perform closed-loop laser welding along the plate surface of the second through hole of the bottom plate frame body and the second panel of the bipolar plate to fix the bottom plate frame body and the second panel of the bipolar plate into one body.

7. The preparation method of the flow battery assembly according to claim 6, characterized in that, step S1 includes: horizontally placing the bipolar plate on a dedicated device for positioning, placing the annular connector in through-hole B of the bipolar plate, and coaxially sleeving through-hole C of the bottom plate frame outside the annular boss A of the annular connector.

8. The preparation method of the flow battery assembly according to claim 7, characterized in that, step S2 includes: performing closed-loop laser welding on the second annular surface of the annular connector to fix the annular connector and through-hole A as a whole; performing closed-loop laser welding on the first annular surface of the annular connector to fix the annular connector and through-hole C as a whole; Preferably, step S2 includes: horizontally placing the bipolar plate on a dedicated device for positioning, sleeving the annular boss B provided in through-hole C of the bottom plate frame into through-hole B of the bipolar plate, then stacking the second surface of the flow channel frame on the first surface of the bipolar plate, aligning the positions of through-hole B and through-hole A, and performing closed-loop laser welding on the annular surface of the annular boss B to fix the annular boss B and through-hole A as a whole.

9. A flow battery stack, comprising a battery stack assembly; characterized in that, the battery stack assembly includes the flow battery assembly according to any one of claims 1 to 8.

10. An energy storage system, comprising a flow battery stack; characterized in that, the flow battery stack includes a flow battery stack according to claim 9.

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