Collector plate and flow battery stack

Abstract

The utility model belongs to the technical field of flow batteries, and particularly relates to a collector plate and a flow battery stack. The collector plate comprises a collector plate body and a leading-out end, wherein the leading-out end is provided with a groove structure and a bent leading-out structure connected with the groove structure; an inner side groove plate of the groove structure is connected with the collector plate body, and an outer side groove plate of the groove structure is connected with a bending lead-out structure; the bending lead-out structure comprises a first sheet and a second sheet, and the first sheet and the second sheet are connected through bending. And a supporting part is arranged between the groove structure of the flow battery stack and the plate frame of the flow frame. The utility model designs a novel collector plate and a flow battery stack. The leading-out end of the collector plate is provided with a groove structure and a bent leading-out structure connected with the groove structure. And a supporting part is arranged between the groove structure and the liquid flow frame. According to the collector plate, the supporting effect on the liquid flow frame is realized, and the overall sealing performance of the galvanic pile is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of liquid flow batteries, and in particular relates to a current collecting plate and a liquid flow battery stack. Background Art

[0002] There are many types of flow batteries. Taking the widely used all-vanadium flow battery as an example, the all-vanadium redox flow battery is a type of redox flow battery with the advantages of long service life, high energy conversion efficiency, good safety, and environmental friendliness. It can be used in large-scale energy storage systems supporting wind power generation and photovoltaic power generation, and is one of the main choices for peak shaving and valley filling and load balancing in power grids.

[0003] The all-vanadium redox flow battery uses vanadium ions of different valence states as the positive and negative redox pairs of the battery, respectively. The positive and negative electrolytes are stored in two storage tanks, respectively. The active electrolyte is driven to the reaction site (battery stack) by an acid-resistant liquid pump and then returned to the storage tank to form a circulating liquid flow loop to realize the charging and discharging process.

[0004] The standard open circuit voltage of a single cell of an all-vanadium liquid flow battery is 1.259V. In order to meet the needs of practical applications, a certain number of single cells are connected in series to form a battery stack in order to obtain the required voltage. An all-vanadium liquid flow battery stack is generally assembled in the form of end plates, current collectors, monopolar plates, electrode frames with electrodes inside, ion exchange membranes, electrode frames with electrodes inside, bipolar plates, ... electrode frames with electrodes inside, ion exchange membranes, electrode frames with electrodes inside, bipolar plates ... electrode frames with electrodes inside, ion exchange membranes, electrode frames with electrodes inside, monopolar plates, current collectors, and end plates, and assembled into a battery stack under compression.

[0005] Most of the current collectors (also called power extraction plates) in the prior art exist independently or are directly drawn out from the inside of the battery stack, and do not participate in any structural sealing and supporting functions. In actual operation, the lead-out part of the current collector needs to be connected to an external cable in order to connect the battery stack to the external power grid. However, the tightening force or torque when connecting the external cable will cause the lead-out part of the current collector to deform, which in turn causes the deformation of the main body of the current collector and affects the conductivity and sealing performance of the battery stack.

[0006] In order to solve the above problems, this application is proposed. Utility Model Content

[0007] In a first aspect, the present application provides a current collecting plate, the current collecting plate 1 comprising: a current collecting plate body 1-1 and a lead-out terminal 1-2, the lead-out terminal 1-2 having a groove structure 1-2-1 and a bent lead-out structure 1-2-2 connected to the groove structure;

[0008] The inner groove plate of the groove structure 1-2-1 is connected to the current collecting plate body 1-1, and the outer groove plate of the groove structure 1-2-1 is connected to the bent lead-out structure 1-2-2;

[0009] The bent lead-out structure 1-2-2 includes: a first sheet and a second sheet, wherein the first sheet and the second sheet are connected by bending.

[0010] Preferably, the bend of the bent lead-out structure 1-2-2 is a right-angle bend.

[0011] A second aspect of the present application provides a liquid flow battery stack, the liquid flow battery stack comprising: a liquid flow frame 2, a bipolar plate, and a current collecting plate 1;

[0012] The bipolar plate is in contact with the current collecting plate 1 to achieve current transmission;

[0013] The current collecting plate 1 comprises: a current collecting plate body 1-1 and a lead-out terminal 1-2, wherein the lead-out terminal 1-2 has a groove structure 1-2-1 and a bent lead-out structure 1-2-2 connected to the groove structure;

[0014] The inner groove plate of the groove structure 1-2-1 is connected to the current collecting plate body 1-1, and the outer groove plate of the groove structure 1-2-1 is connected to the bent lead-out structure 1-2-2;

[0015] The bent lead-out structure 1-2-2 comprises: a first sheet and a second sheet, wherein the first sheet and the second sheet are connected by bending;

[0016] A supporting component 3 is arranged between the groove structure 1 - 2 - 1 and the plate frame of the liquid flow frame 2 .

[0017] Preferably, the outer groove plate of the groove structure 1 - 2 - 1 supports the outer edge of the plate frame of the liquid flow frame 2 .

[0018] More preferably, the outer groove plate of the groove structure 1-2-1 is interference fit with the outer edge of the plate frame of the liquid flow frame 2, that is, the bottom of the outer edge of the plate frame of the liquid flow frame 2 is embedded in the outer groove plate of the groove structure 1-2-1. At this time, the outer edge of the plate frame of the liquid flow frame 2 is slightly deformed.

[0019] Preferably, the flow battery stack further comprises: an isolation plate 4 located on one side of the current collecting plate;

[0020] The isolation plate 4 has a liquid flow hole and a current collecting plate support portion 4-1, and the current collecting plate support portion 4-1 has a first support portion 4-1-1 configured to support the groove structure 1-2-1 and a second support portion 4-1-2 configured to support the bent lead-out structure 1-2-2.

[0021] Preferably, the current collecting plates 1 are located at both ends and / or in the middle of the flow battery stack.

[0022] Preferably, the isolation plates 4 are located at both ends and / or in the middle of the flow battery stack.

[0023] A third aspect of the present application provides a method for preventing the lead-out portion of the current collecting plate from being deformed by external forces and affecting the sealing of the liquid flow frame, which uses the liquid flow battery stack described in any one of the second aspects.

[0024] Compared with the prior art, this application has the following beneficial effects:

[0025] 1. In the prior art, the lead-out portion of the current collecting plate is only led out to the outside of the battery stack through a right-angle bend so as to be connected to an external cable. The entire lead-out portion of the current collecting plate does not participate in any structural sealing and supporting functions. For example, the current collecting plate and the liquid flow frame are isolated from each other. The present application designs a new type of current collecting plate, in which the lead-out end of the current collecting plate has a groove structure and a bent lead-out structure connected to the groove structure. A supporting component is provided between the groove structure and the liquid flow frame. This type of current collecting plate realizes the supporting effect on the liquid flow frame and improves the overall sealing performance of the battery stack.

[0026] 2. In the present application, the portion of the current collecting plate extending from the interior of the battery stack supports the liquid flow frame, thereby simplifying the structure of the current collecting plate and the support of the liquid flow frame of the battery stack.

[0027] 3. This application solves the structural method of leading the current collector from the inside of the high-power battery stack (single cell above 100kW). The current collector is upgraded from the existing single conductive function to the function of both conductive and supporting the liquid flow frame.

[0028] 4. The present application solves the problem of the influence of the deformation of the lead-out part of the current collector plate due to external force on the sealing of the internal end-piece outer frame. The structural design of the present application is that when the cable is installed outside the lead-out end of the current collector plate, the deformation of the lead-out end of the current collector plate caused by the tightening force or torque will not be transmitted to the current collector plate body inside the current collector plate. The reason is: due to the interference fit between the lead-out end of the current collector plate and the outer edge of the liquid flow frame, and the isolation plate is supported below the lead-out end of the current collector plate. The lead-out end of the current collector plate is completely fixed between the liquid flow frame and the isolation plate. Therefore, the tightening force or torque when the external cable is connected will cause the deformation force of the lead-out end of the current collector plate to be transmitted only to the outer groove plate of the groove structure of the lead-out end (i.e., the interference fit), and therefore will not affect the support and sealing of the collector plate part and the liquid flow outer frame inside the outer groove plate of the groove structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of installing the front collecting plate, liquid flow frame, support component and isolation plate in the first embodiment.

[0030] Figure 2Schematic diagram of the positions of the rear collecting plate, liquid flow frame, support component and isolation plate installed in the first embodiment.

[0031] List of reference numerals:

[0032] 1. Current collecting plate, 1-1. Current collecting plate body, 1-2. Lead-out end, 1-2-1. Groove structure, 1-2-2. Bend lead-out structure, 2. Liquid flow frame, 3. Support component, 4. Isolation plate, 4-1. Current collecting plate support part, 4-1-1. First support part, 4-1-2. Second support part. DETAILED DESCRIPTION

[0033] The present application is further described in detail below in conjunction with embodiments.

[0034] Those skilled in the art will appreciate that the following examples are only used to illustrate the present application and should not be considered to limit the scope of the present application. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the art or the product specifications are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0035] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" to another element, it may be directly connected to the other element, or there may be intermediate elements. In addition, the "connection" used herein may include wireless connections.

[0036] In the description of this application, unless otherwise specified, "plurality" means two or more. The terms "inside", "upper", "lower", etc. indicate positions or state relationships based on the positions or state relationships shown in the drawings, which are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operate in a specific position, and therefore cannot be understood as limiting this application.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "provided with" 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. For ordinary technicians in this field, the specific meanings of the above terms in this application are understood according to specific circumstances.

[0038] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0039] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0040] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution. If not otherwise specified, all technical features and optional technical features of the present application can be combined with each other to form a new technical solution. If not otherwise specified, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0041] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0042] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B".

[0043] A current collecting plate, the current collecting plate 1 comprises: a current collecting plate body 1-1 and a lead-out terminal 1-2, the lead-out terminal 1-2 having a groove structure 1-2-1 and a bent lead-out structure 1-2-2 connected to the groove structure.

[0044] The inner groove plate of the groove structure 1-2-1 is connected to the current collecting plate body 1-1, and the outer groove plate of the groove structure 1-2-1 is connected to the bent lead-out structure 1-2-2.

[0045] The bent lead-out structure 1-2-2 includes: a first sheet and a second sheet, wherein the first sheet and the second sheet are connected by bending.

[0046] In a preferred embodiment, the bending of the bent lead-out structure 1-2-2 is a right-angle bend. Of course, bends at other angles are also possible.

[0047] The present application also provides a liquid flow battery stack, which includes: a liquid flow frame 2, a bipolar plate, and a current collecting plate 1.

[0048] The bipolar plate is in contact with the current collecting plate 1 to achieve current transmission;

[0049] The current collecting plate 1 comprises: a current collecting plate body 1-1 and a lead-out terminal 1-2, wherein the lead-out terminal 1-2 has a groove structure 1-2-1 and a bent lead-out structure 1-2-2 connected to the groove structure;

[0050] The inner groove plate of the groove structure 1-2-1 is connected to the current collecting plate body 1-1, and the outer groove plate of the groove structure 1-2-1 is connected to the bent lead-out structure 1-2-2; the bent lead-out structure 1-2-2 includes: a first sheet and a second sheet, and the first sheet and the second sheet are connected by bending;

[0051] A supporting component 3 is arranged between the groove structure 1 - 2 - 1 and the plate frame of the liquid flow frame 2 .

[0052] The shape of the support component 3 is configured to support the plate frame of the liquid flow frame 2 in the groove structure 1-2-1. In a preferred embodiment, a sealing rib is provided on the side of the plate frame of the liquid flow frame 2 facing the support component 3. A support rib matching the above-mentioned sealing rib is also provided on the side of the support component 3 facing the plate frame of the liquid flow frame 2.

[0053] In a preferred embodiment, the outer groove plate of the groove structure 1 - 2 - 1 supports the outer edge of the plate frame of the liquid flow frame 2 .

[0054] In a preferred embodiment, the flow battery stack further comprises: a separator 4 located on one side of the current collecting plate. The separator 4 has a flow hole and a current collecting plate support portion 4-1, and the current collecting plate support portion 4-1 has a first support portion 4-1-1 configured to support the groove structure 1-2-1 and a second support portion 4-1-2 configured to support the bent lead-out structure 1-2-2. The flow hole is used to provide an electrolysis flow path.

[0055] In a preferred embodiment, the current collecting plate 1 is located at both ends and / or in the middle of the flow battery stack.

[0056] In a preferred embodiment, the separator 4 is located at both ends and / or in the middle of the flow battery stack. The arrangement order is: flow frame 2, bipolar plate / monopolar plate, current collecting plate 1, separator 4. The hollow part of the flow frame 2 is used to stack electrodes and membranes.

[0057] In the battery stack, the liquid flow frame 2, bipolar plates, current collecting plates 1, separator plates 4 and other components are stacked and fixed in the middle by rigid end plates at both ends. The rigid end plates at both ends can be fixed by bolts or other means.

[0058] In a preferred embodiment, a rigid end plate is provided on one side of the isolation plate 4 at the end.

[0059] In a preferred embodiment, the liquid flow frame 2, the isolation plate 4, and the support component 3 are all made of plastic, and the current collecting plate 1 is an integrated copper plate.

[0060] The present application also provides a method for preventing the lead-out portion of the current collecting plate from being deformed by external force and affecting the sealing of the outer frame, which uses the liquid flow battery stack described in any one of the above items.

[0061] The current collecting plates 1 are located at both ends of the flow battery stack as a first embodiment:

[0062] The last current collector plate 1 is led out from the inside of the battery stack and needs to pass through the last liquid flow frame 2, such as the structure Figure 1 As shown. A final piece support sheet matching the flow channel of the final piece liquid flow frame 2 is provided between the final piece liquid flow frame 2 and the final piece current collecting plate 1 as a supporting component 3. The final piece support sheet is wrapped on three sides by the groove structure 1-2-1 of the final piece current collecting plate 1. The bottom surface of the groove structure 1-2-1 is perpendicular to the two side surfaces. Of course, in other embodiments, the bottom surface of the groove structure 1-2-1 and the two side surfaces may be at other angles. Other angles may be, for example, obtuse angles. At this time, a supporting component 3 of a corresponding structure can be matched.

[0063] A final separator 4 is also provided on the other side of the final current collecting plate 1. The final current collecting plate 1 is completely fitted with the final separator 4. The final separator 4 supports the lead-out end 1-2 portion of the final current collecting plate 1 to support the sealing ribs of the final liquid flow frame 2, thereby achieving sealing of the electrolyte in the battery stack. In this embodiment, different liquid flow frames 2 achieve sealing of the electrolyte in the battery stack through the sealing ribs between each other. Of course, in other embodiments, other methods such as sealing strips can also be used for sealing. The separator 4 has a liquid flow hole and a current collecting plate support portion 4-1, and the current collecting plate support portion 4-1 has a first support portion 4-1-1 configured to support the groove structure 1-2-1 and a second support portion 4-1-2 configured to support the bent lead-out structure 1-2-2. In the first embodiment, the first support portion 4-1-1 and the second support portion 4-1-2 are two platform structures with different heights.

[0064] The last current collector plate 1 needs to pass through the last liquid flow frame 2 to be led out from the inside of the battery stack. The outer groove plate of the groove structure 1-2-1 supports the outer edge of the plate frame of the liquid flow frame 2, and is configured to have an interference fit between the current collector plate 1 and the last liquid flow frame 2 at the edge of the last liquid flow frame 2. The designed interference is 0.1mm, and the acceptable interference range is between 0-0.2mm. Specific structure Figure 2 As shown, the embedding distance between the bottom of the plate frame outer edge of the liquid flow frame 2 and the upper inner edge of the outer groove plate of the groove structure 1-2-1 is 0 to 0.2 mm, that is, the lower portion of the plate frame outer edge of the liquid flow frame 2 is deformed, so that while the supporting component 3 supports the liquid flow frame 2, the outer groove plate of the groove structure 1-2-1 also plays a role in supporting the liquid flow frame 2.

[0065] The thickness of the last current collecting plate 1 is in the range of 2-5 mm.

[0066] Of course, the matching structure of the above-mentioned liquid flow frame 2, current collecting plate 1, support component 3, and isolation plate 4 can also be set at any middle position of the battery stack.

Claims

1. A current collecting plate, characterized in that: The current collecting plate (1) comprises: a current collecting plate body (1-1) and a lead-out terminal (1-2), wherein the lead-out terminal (1-2) has a groove structure (1-2-1) and a bent lead-out structure (1-2-2) connected to the groove structure; The inner groove plate of the groove structure (1-2-1) is connected to the current collecting plate body (1-1), and the outer groove plate of the groove structure (1-2-1) is connected to the bent lead-out structure (1-2-2); The bent lead-out structure (1-2-2) comprises a first sheet and a second sheet, wherein the first sheet and the second sheet are connected by bending.

2. The current collecting plate according to claim 1, characterized in that: The bending of the bent lead-out structure (1-2-2) is a right-angle bend.

3. A liquid flow battery stack, characterized in that: The liquid flow battery stack comprises: a liquid flow frame (2), a bipolar plate, and a current collecting plate (1); The bipolar plate and the current collecting plate (1) are in contact to achieve current transmission; The current collecting plate (1) comprises: a current collecting plate body (1-1) and a lead-out terminal (1-2), wherein the lead-out terminal (1-2) has a groove structure (1-2-1) and a bent lead-out structure (1-2-2) connected to the groove structure; The inner groove plate of the groove structure (1-2-1) is connected to the current collecting plate body (1-1), and the outer groove plate of the groove structure (1-2-1) is connected to the bent lead-out structure (1-2-2); the bent lead-out structure (1-2-2) comprises: a first sheet and a second sheet, and the first sheet and the second sheet are connected by bending; A supporting component (3) is arranged between the groove structure (1-2-1) and the plate frame of the liquid flow frame (2).

4. The flow battery stack according to claim 3, characterized in that: The outer groove plate of the groove structure (1-2-1) supports the outer edge of the plate frame of the liquid flow frame (2).

5. The flow battery stack according to claim 3, characterized in that: The liquid flow battery stack further comprises: an isolation plate (4) located on one side of the current collecting plate; The isolation plate (4) has a liquid flow hole and a current collecting plate support portion (4-1), and the current collecting plate support portion (4-1) has a first support portion (4-1-1) configured to support the groove structure (1-2-1) and a second support portion (4-1-2) configured to support the bent lead-out structure (1-2-2).

6. The flow battery stack according to claim 3, characterized in that: The current collecting plates (1) are located at both ends and / or in the middle of the liquid flow battery stack.

7. The flow battery stack according to claim 5, characterized in that: The isolation plates (4) are located at both ends and / or in the middle of the liquid flow battery stack.

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