Electrode frame assembly of flow battery, electric pile unit and electric pile

Abstract

The invention provides a flow battery electrode frame assembly, a galvanic pile unit and a galvanic pile, the flow battery electrode frame assembly comprises an outer frame body, the middle part of the outer frame body is a first hollow structure for embedding a first electrode, the upper and lower parts of the front and back surfaces of the outer frame body are provided with electrolyte flow channel grooves, and the four corners of the outer frame body are respectively provided with electrolyte flow holes communicated with the corresponding electrolyte flow channel grooves; a plurality of first distribution runners communicated with the electrolyte runner groove are arranged on the front surface of the outer frame body and close to the edge of the first hollow structure; a film pressing frame mounting groove is formed in the reverse side of the outer frame body and surrounds the edge of the first hollow structure; the middle part of the film pressing frame is a second hollow structure for embedding a second electrode, and one surface of the film pressing frame is provided with a plurality of second distribution runners; and after the film pressing frame is embedded in the film pressing frame mounting groove, the second distribution flow channel is connected and communicated with the electrolyte flow channel groove on the side where the second distribution flow channel is located. According to the technical scheme, the area ratio of the electrode reaction region can be ensured to the maximum extent, and the reaction efficiency of the flow battery is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of liquid flow batteries, and specifically relates to a liquid flow battery electrode frame assembly and a battery stack unit and a battery stack including the electrode frame assembly. Background Art

[0002] Liquid flow battery is a highly efficient electrochemical energy storage technology. The working medium of liquid flow battery is electrolyte, which is generally an acidic liquid. The loss of electrolyte will not only cause a decrease in charging and discharging energy, but also cause environmental pollution or safety accidents. In the entire liquid flow battery system, the stack is its core power component and the weakest sealing component of the entire system. The liquid flow battery stack is composed of multiple components such as electrodes, ion conduction membranes, electrode frames, bipolar plates, current collectors, end plates, etc. If there is a problem with the sealing in any link, it will lead to serious consequences. Therefore, how to achieve reliable connection of the stack through structural design is a technical problem.

[0003] The prior art battery stack design is usually as follows Figure 1 As shown, the bipolar plates (1 and 1' in the figure), electrode frames (2 and 2' in the figure), electrodes (3 and 3' in the figure), ion membranes (4 in the figure) and other components are stacked and filter-pressed, that is, the bipolar plates, electrode frames, electrodes, ion membranes, sealing wires and other key components are stacked (generally dozens of single cells are stacked up and down), and then the end plates (5 and 5' in the figure) are used on the outermost layer to apply pre-tightening force through the spring to ensure the sealing. Due to the large number of components and the large plane area, the sealing design is more difficult on the one hand. Although the conventional practice is to use wire sealing or concave-convex structure to solve it, it is difficult to achieve in industrial-scale production because there are too many links to consider leakage prevention; on the other hand, the impact is that the assembly is cumbersome, inefficient and costly, which has also become an obstacle to the commercialization of all-vanadium liquid flow batteries.

[0004] To this end, some existing technologies have made improvements. For example, the electrode frame and the bipolar plate are integrated into one design. Although the assembly amount is reduced, it cannot make a good improvement in the key ion membrane sealing. Or although the electrode frame and the ion membrane are integrated, there is a lack of reliable connection between the components, and there is no anti-corrosion structural design, and the reliability of battery operation is poor; or although the electrode and the ion membrane are combined and assembled into an integral component through the electrode frame, how to achieve a uniform flow field in the electrode reaction area to improve the reaction efficiency, and how to design the corresponding electrolyte flow channel in the integrated structure have also become difficulties. Summary of the invention

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an electrode frame assembly, a stack unit and a stack of a liquid flow battery to solve the technical problems in the prior art that the assembly of multiple flow battery components is cumbersome and costly, the flow field in the electrode reaction zone is uneven, the electrolyte flow channel design is cumbersome or the electrolyte flow channel occupies a large space, resulting in a large component size.

[0006] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0007] In the first aspect, an embodiment of the present invention provides a liquid flow battery electrode frame assembly, comprising: an outer frame body and a film pressing frame; the middle portion of the outer frame body is a first hollow structure for embedding a first electrode, and electrolyte flow channel grooves are provided on the upper and lower portions of both the front and back sides, and electrolyte flow holes connected to the corresponding electrolyte flow channel grooves are provided at the four corners of the outer frame body; a plurality of first distribution channels connected to the electrolyte flow channel grooves are provided at the front side of the outer frame body, close to the edge of the first hollow structure; a film pressing frame mounting groove is provided on the back side of the outer frame body, surrounding the edge of the first hollow structure; the middle portion of the film pressing frame is a second hollow structure for embedding a second electrode, and a plurality of second distribution channels are provided on one side; when the film pressing frame is engaged in the film pressing frame mounting groove, the second distribution channel is connected to the electrolyte flow channel on the side where it is located.

[0008] Furthermore, the first hollow structure, the film pressing frame and the second hollow structure are all in the shape of an irregular rectangular parallelepiped with chamfered corners.

[0009] Furthermore, the electrolyte flow channel at least starts from the first chamfer on one side of the first hollow structure and ends at the second chamfer.

[0010] Furthermore, one end of the electrolyte flow channel away from the electrolyte flow hole gradually shrinks toward the first hollow structure.

[0011] Furthermore, a plurality of the first distribution channels and the second distribution channels are arranged along the changing direction of the corresponding connected electrolyte channel grooves; the first distribution channels and the second distribution channels are arranged obliquely to allow the electrolyte to flow in and the distance between them gradually narrows.

[0012] Furthermore, the width and vertical length of the first distribution channel and the second distribution channel gradually become wider and shorter along the flow direction of the electrolyte in the electrolyte channel groove.

[0013] Furthermore, the electrode frame assembly also includes a blocking piece; the blocking piece covers the electrolyte flow channel groove portion around the electrolyte flow hole and at least covers the electrolyte flow channel groove portion corresponding to each chamfer of the first hollow structure.

[0014] Furthermore, a first sealing wire groove is provided in the film pressing frame installation groove, and a second sealing wire groove is provided along the edge on both the front and back sides of the outer frame body; an ear piece extending outward is also provided on the edge of the outer frame body, and a positioning hole and a connecting hole are provided on the ear piece.

[0015] In the second aspect, an embodiment of the present invention also provides a liquid flow battery stack unit, comprising the above-mentioned electrode frame assembly, an ion exchange membrane, a first electrode, a second electrode and a bipolar plate; the ion exchange membrane is fixed in the ion membrane mounting groove, the first electrode is embedded in the first hollow structure and matches the shape of the first hollow structure, and the second electrode is embedded in the second hollow structure and matches the shape of the second hollow structure; the film pressing frame is embedded in the ion membrane mounting groove and sealed; the electrolyte flow channel groove is covered with a sealing film; the bipolar plates are respectively covered on the front and back sides of the outer frame and are tightly fixed through the fixing holes on the outer frame.

[0016] In a third aspect, an embodiment of the present invention further provides a liquid flow battery stack, comprising a plurality of the above-mentioned stack units, current collecting plates and end plates; the stack units are repeatedly arranged, the end plates are respectively located on the outermost sides and the stack units are fastened together through the connecting holes.

[0017] Beneficial effects of the present invention:

[0018] The electrode frame of the present technical solution can be combined into an integrated component that accommodates the ion exchange membrane and the positive and negative electrodes through an outer frame and a film pressing frame. During subsequent assembly, it is only necessary to fix the bipolar plate on the front and back sides of the integrated electrode frame. This not only reduces the parts required for the assembly of the flow battery and effectively improves the assembly efficiency, but also the ingenious design of mutual hollowing and embedding can reduce the overall thickness and volume of the electrode frame. In addition, the first annular sealing groove of the inner layer and the second annular sealing groove of the outer layer can effectively prevent the leakage of the positive and negative electrolytes, so that the flow battery can operate reliably without adding additional assembly parts or structures to the integrated electrode frame.

[0019] At the same time, the chamfered rectangular positive and negative electrode plates and the matching electrolyte flow channel design can allow a portion of the electrolyte flowing into the electrolyte flow hole to flow out along the diagonal direction of the electrode plate, thereby maximizing the area ratio of the electrode reaction zone and improving the reaction efficiency of the flow battery.

[0020] In addition, the design of the first distribution channel and the second distribution channel matching the electrolyte flow channel trough structure can, on the one hand, ensure uniform electrolyte flow rate and more uniform flow field in the electrode reaction area; on the other hand, compared with the traditional multi-layer flow channel distribution design, the present technical solution has only one layer of flow channel distribution, which optimizes the flow channel distribution structure and makes it simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the battery stack structure in the prior art.

[0022] Figure 2 1 is an exploded view of an electrode frame assembly according to an embodiment of the present invention.

[0023] Figure 3 It is a cross-sectional view of the electrode frame assembly after being integrally installed according to an embodiment of the present invention.

[0024] Figure 4 It is a front view of the outer frame of the electrode frame assembly according to an embodiment of the present invention.

[0025] Figure 5 It is a rear view of the outer frame of the electrode frame assembly according to an embodiment of the present invention.

[0026] Figure 6 It is a front view of the film pressing frame of the electrode frame assembly according to an embodiment of the present invention.

[0027] Figure 7 It is a rear view of the film pressing frame of the electrode frame assembly according to an embodiment of the present invention.

[0028] Figure 8 It is an exploded cross-sectional view of a liquid flow battery stack unit according to an embodiment of the present invention.

[0029] Fig. 9 It is a schematic structural diagram of the electrode frame assembly baffle according to an embodiment of the present invention.

[0030] [Description of Reference Numerals]

[0031] 1 and 1': bipolar plates; 2 and 2': electrode frames; 3 and 3': electrodes; 4: ion membrane; 5 and 5': end plates;

[0032] 10: outer frame; 11: first hollow structure; 12: electrolyte flow channel; 13: electrolyte flow hole; 14: first distribution channel; 15: ion membrane installation groove; 16: first sealing wire groove; 17: second sealing wire groove; 18: baffle; 19: ear piece; 191: fixing hole and connection hole;

[0033] 20: film pressing frame; 21: second hollow structure; 22: second distribution channel;

[0034] 30: first electrode; 40: second electrode; 50: ion exchange membrane; 60: bipolar plate. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0036] like Figure 2 and Figure 7 As shown, an embodiment of the present invention provides an electrode frame assembly for a liquid flow battery, including an outer frame 10 and a film pressing frame 20. After the film pressing frame 20 is tightly embedded in the outer frame 10, it can be assembled into an integrated electrode frame that accommodates ion exchange membranes, positive electrode plates and negative electrode plates.

[0037] refer to Figure 3 and Figure 4 , the outer frame 10 is divided into two sides, front and back. The middle part of the outer frame 10 is a first hollow structure 11 for embedding the first electrode 30. In the present embodiment, the first hollow structure 11 is a rectangular parallelepiped with chamfers at all four corners, that is, the inner contour of the outer frame 10 after the orthographic projection is an octagon. The front side of the outer frame 10, the upper side and the lower side of the first hollow structure 11 are all provided with positive electrode electrolyte flow channels 12, and the reverse side of the outer frame 10, the upper side and the lower side of the first hollow structure 11 are all provided with negative electrode electrolyte flow channels 12. Each electrolyte flow channel starts from at least the first chamfer on one side of the first hollow structure 11 to the second chamfer. That is, assuming that the paths along the first chamfered edge, the upper edge, and the second chamfered edge of the first hollow structure 11 are A1, A2, and A3, respectively, and the paths along the third chamfered edge, the lower edge, and the fourth chamfered edge of the first hollow structure 11 are B1, B2, and B3, respectively, then the path of the electrolyte flow channel groove located on the upper side of the first hollow structure 11 includes at least part A1, all A2, and part A3, and the maximum length path is all A1, all A2, and all A3. Similarly, the path of the electrolyte flow channel groove located on the lower side of the first hollow structure 11 includes at least part B1, all B2, and part B3, and the maximum length path is all B1, all B2, and all B3. In this way, the area where the electrolyte flows through the electrode plate can be maximized. Compared with a completely rectangular electrode plate or an electrolyte flow channel design that simply flows in and out from the opposite sides of the electrode plate, the technical means of the present invention can obviously make full use of the corner area of ​​the electrode plate and the area where the other two side surfaces of the electrode plate are located, thereby relatively reducing the area occupied by the electrode plate.

[0038] In particular, one end of each electrolyte flow channel 12 away from the electrolyte flow hole 13 gradually shrinks toward the first hollow structure 11. Specifically, the chamfer of the first hollow structure 11 is smoothly transitioned, which is conducive to uniform flow field in the electrode corner area.

[0039] The four corners of the outer frame 10 are provided with electrolyte flow holes 13, which are respectively the positive electrolyte inlet channel, the positive electrolyte outlet channel, the negative electrolyte inlet channel and the negative electrolyte outlet channel. Among them, the positive electrolyte inlet channel and the positive electrolyte outlet channel are respectively connected with the positive electrolyte flow channel groove 12 on the upper side of the first hollow structure 11 and the positive electrolyte flow channel groove 12 on the lower side of the first hollow structure 11, and the two are arranged in a diagonal relationship. Similarly, the negative electrolyte inlet channel and the negative electrolyte outlet channel are respectively connected with the negative electrolyte flow channel groove 12 on the upper side of the first hollow structure 11 and the negative electrolyte flow channel groove 12 on the lower side of the first hollow structure 11, and the two are arranged in a diagonal relationship. In particular, each electrolyte flow hole 13 is arranged as much as possible in correspondence with each chamfer of the first hollow structure 11, so that the flow rate of each position of the electrolyte can be better adjusted to be uniform, and it is also convenient for the electrolyte to flow into the chamfer of the electrode plate.

[0040] In this embodiment, on the front of the outer frame 10, a plurality of first distribution channels 14 connected to the positive electrode electrolyte flow channel groove 12 are arranged at intervals adjacent to the upper and lower edges of the first hollow structure 11, so as to help regulate the flow rate and flow rate of the electrolyte flowing through the electrolyte flow channel groove into the electrode plate. The plurality of first distribution channels 14 are arranged along the changing direction of the correspondingly connected electrolyte flow channel grooves 12, which is manifested as the plurality of first distribution channels 14 extending from one end to the other end of the correspondingly connected positive electrode electrolyte flow channel grooves 12 and arranged at intervals. In addition, the first distribution channels 14 are arranged obliquely along the flow direction of the electrolyte so that the electrolyte can flow in more smoothly.

[0041] Since the electrolyte flow rate near the electrolyte flow hole 13 is greater than the electrolyte flow rate far away from the electrolyte flow hole 13, the width of the first distribution channel 14 gradually becomes narrower from near to far relative to the electrolyte flow hole 13 and the height perpendicular to the edge of the first hollow structure 11 becomes shorter from near to far. On the one hand, it can better ensure the uniform flow of the electrolyte and thus the uniform flow field in the electrode reaction area. On the other hand, it can effectively reduce the levels of the distribution channels. For example, the present technical solution only requires one layer of distribution channels, while the prior art may require two or even three layers of distribution channels. Therefore, the design of the distribution channels is effectively simplified and the occupied area of ​​the distribution channels is reduced, so that the electrode plates obtain a larger assembly space and thus increase the area of ​​the reaction area, thereby improving the performance of the liquid flow battery.

[0042] On the reverse side of the outer frame 10, a film pressing frame 20 installation groove is provided around the edge of the first hollow structure 11 for installing the ion exchange membrane and embedding the film pressing frame 20. Two annular first sealing wire grooves 16 are provided in the film pressing frame 20 installation groove.

[0043] refer to Figure 5 and Figure 6 , the film pressing frame 20 is divided into a front side and a back side. In this embodiment, the film pressing frame 20 and the second hollow structure 21 in the middle thereof are also in the shape of a rectangular parallelepiped with chamfered corners, that is, the outer contour and inner contour of the positive projection are both octagonal, which is adapted to the shape of the first hollow structure 11. The second hollow structure 21 is used to embed the second electrode 40. Among them, the upper and lower sides of the front of the film pressing frame 20 are provided with a plurality of second distribution channels 22 arranged at intervals. When the film pressing frame 20 is embedded in the ion membrane installation groove 15, the second distribution channel 22 is connected to the upper and lower electrolyte flow channel grooves 12 on the back of the outer frame 10. The structural principle of the second distribution channel 22 is the same as that of the first distribution channel 14, that is, the structure of the front and back sides of the integrated electrode frame after the film pressing frame 20 is installed is the same. Therefore, the descriptions of "positive electrode", "negative electrode", "front side", "back side", "upper side", "lower side" and the like described in this embodiment are all for assisting the understanding of the technical principles of the scheme of the present invention, rather than restrictive descriptions.

[0044] It should be noted that, although the shapes of the first hollow structure 11, the film pressing frame 20 mounting groove, the film pressing frame 20 and the second hollow structure 21 in the present embodiment are preferably rectangular parallelepiped with straight chamfers, according to the principle of the present technical solution, after reading the present invention, it can be naturally understood that the rectangular parallelepiped with arc chamfers is also covered within the protection scope of the present invention. At the same time, although the annular closed film pressing frame 20 is used as the preferred means in the present invention, as long as it can be embedded in the film pressing frame 20 mounting groove and can play a certain role in sealing the ion membrane and has a second distribution flow channel 22, it should belong to the protection scope of the present invention. For example, the film pressing frame 20 can be an open type including an upper half and a lower half. Similarly, the film pressing frame 20 mounting groove can also be changed in the same way as the film pressing frame 20 structure.

[0045] In particular, the electrode frame assembly of this embodiment also includes a baffle 18; the baffle 18 covers the electrolyte flow channel portion around the electrolyte flow hole 13 and at least covers the electrolyte flow channel portion corresponding to each chamfer of the first hollow structure 11, thereby preventing electrolyte leakage here.

[0046] In particular, the front and back sides of the outer frame 10 in this embodiment are both provided with an annular second sealing groove 17 arranged along the edge; the edge of the outer frame 10 is also provided with an outwardly extending ear piece 19, and the ear piece 19 is provided with a positioning hole and a connecting hole 191.

[0047] In summary, this technical solution not only integrates multiple components into an assembly, reducing the assembly cost and parts of the liquid flow battery, but also can ensure that the area of ​​the electrode reaction zone is maximized, thereby relatively reducing the electrode area and reducing the volume of the electrode frame. At the same time, it also simplifies the electrolyte distribution flow channel and ensures that the flow field in the electrode reaction zone is uniform.

[0048] Reference Figure 8 and attached Fig. 9 This embodiment also provides a flow battery stack unit, including the above-mentioned electrode frame assembly, an ion exchange membrane 50, a first electrode 30, a second electrode 40 and a bipolar plate 60. The ion exchange membrane 50 is fixed in the ion membrane mounting groove 15, and the first electrode is embedded in the first hollow structure 11 and matches the shape of the first hollow structure 11.

[0049] The second electrode is embedded in the second hollow structure 21 and matches the shape of the second hollow structure 21, so that an ion exchange membrane is spaced between the first electrode and the second electrode. The membrane pressing frame 20 is embedded in the ion membrane installation groove 15, and the sealing wire in the first sealing wire groove 16 is pressed while fixing the ion exchange membrane 50, so as to prevent the infiltration of the positive and negative electrolytes.

[0050] The electrolyte flow channel 12 is covered with a sealing film and the electrolyte flow hole 13 is covered with a baffle 18. The bipolar plate 60 covers the front and back sides of the outer frame 10 respectively and compresses the sealing line in the second sealing line groove 17 to prevent electrolyte leakage, and is tightly fixed through the fixing hole 191 on the outer frame 10.

[0051] This embodiment also provides a flow battery stack structure, including multiple stack units, current collecting plates and end plates as described above; multiple stack units are repeatedly arranged, and the end plates are respectively located on the outermost sides and the stack units are fastened together through connecting holes 191.

[0052] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0055] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0056] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A liquid flow battery electrode frame assembly, characterized in that include The outer frame has a first hollow structure in the middle for embedding the first electrode and electrolyte flow channels are provided at the upper and lower parts of both the front and back sides. The four corners of the outer frame are respectively provided with electrolyte flow holes connected to the corresponding electrolyte flow channels; the front side of the outer frame is provided with a plurality of first distribution channels connected to the electrolyte flow channels close to the edge of the first hollow structure; the back side of the outer frame is provided with a film pressing frame mounting groove around the edge of the first hollow structure; The film pressing frame has a second hollow structure in the middle for embedding the second electrode and one side of the frame is provided with a plurality of second distribution channels; when the film pressing frame is embedded in the film pressing frame mounting groove, the second distribution channel is connected to the electrolyte channel groove on the side.

2. A flow battery electrode frame assembly as claimed in claim 1, characterized in that The first hollow structure, the film pressing frame and the second hollow structure are all in the shape of an irregular rectangular parallelepiped with chamfered corners.

3. A flow battery electrode frame assembly as claimed in claim 2, characterized in that The electrolyte flow channel groove at least starts from the first chamfer on one side of the first hollow structure to the second chamfer.

4. A flow battery electrode frame assembly as described in any one of claims 1 to 3, characterized in that One end of the electrolyte flow channel away from the electrolyte flow hole gradually shrinks toward the first hollow structure.

5. A flow battery electrode frame assembly as described in any one of claims 1 to 3, characterized in that The plurality of first distribution channels and the second distribution channels are arranged along the changing direction of the correspondingly connected electrolyte channel grooves; the first distribution channels and the second distribution channels are arranged obliquely to allow the electrolyte to flow in and the distance between them gradually narrows.

6. A liquid flow battery electrode frame assembly as described in any one of claims 1 to 3, characterized in that The width and vertical length of the first distribution flow channel and the second distribution flow channel gradually become wider and shorter along the flow direction of the electrolyte in the electrolyte flow channel groove.

7. A flow battery electrode frame assembly as claimed in claim 3, characterized in that The electrode frame assembly further includes a baffle; the baffle covers the electrolyte flow channel portion around the electrolyte flow hole and at least covers the electrolyte flow channel portion corresponding to each chamfer of the first hollow structure.

8. A flow battery electrode frame assembly as claimed in claim 1, characterized in that A first sealing wire groove is arranged in the film pressing frame installation groove, and a second sealing wire groove arranged along the edge is arranged on both the front and back sides of the outer frame body; an ear piece extending outward is also arranged at the edge of the outer frame body, and a positioning hole and a connecting hole are arranged on the ear piece.

9. A liquid flow battery stack unit, characterized in that It comprises an electrode frame assembly, an ion exchange membrane, a first electrode, a second electrode and a bipolar plate as described in any one of claims 1 to 8; the ion exchange membrane is fixed in the ion membrane mounting groove, the first electrode is embedded in the first hollow structure and matches the shape of the first hollow structure, and the second electrode is embedded in the second hollow structure and matches the shape of the second hollow structure; the film pressing frame is embedded in the ion membrane mounting groove and is sealed; the electrolyte flow channel groove is covered with a sealing film; the bipolar plates are respectively covered on the front and back sides of the outer frame and are tightly fixed through the fixing holes on the outer frame.

10. A liquid flow battery stack, characterized in that comprising a plurality of battery stack units, current collecting plates and end plates as claimed in claim 9; The stack units are arranged repeatedly, the end plates are respectively located at the outermost two sides, and the stack units are fastened and connected as a whole through the connection holes.

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