Bidirectional current collecting electrode plate

Abstract

The utility model belongs to the technical field of all-vanadium redox flow batteries, and particularly relates to a bidirectional current collecting electrode plate which comprises a plate body, an electrode area used for being in contact with an electrode is arranged in the middle of the surfaces of the two sides of the plate body, four electrolyte passing holes are formed in the four corners of the plate body, and a diversion groove is formed in the electrode area among the four electrolyte passing holes. The surface of the electrode area of the plate body is concave downwards to form a space for containing an electrode, at least one pressure balance hole is formed in the space, a pressure bearing table is arranged on the periphery of the pressure balance hole, and an annular sealing groove is formed in the pressure bearing table. Compared with the prior art, the utility model has the beneficial effects that: 1) the pressure balance hole is formed in the middle of the electrode area of the plate body, so that the plate body is stressed more uniformly, the leakage problem caused by deformation of the plate body after a plurality of electrode plates are superposed and pressed is effectively reduced, and the problem of corrosion of acidic electrolyte to the environment is favorably improved; and 2) the deformation of the plate body is small, and the production efficiency of the electrolyte of the all-vanadium redox flow battery can be obviously improved.

Description

Technical Field

[0001] This utility model belongs to the field of vanadium redox flow battery technology, and particularly relates to a bidirectional current collector electrode plate. Background Technology

[0002] Vanadium redox flow battery (VRB) is a new type of high-efficiency, high-capacity energy storage battery with long lifespan and high safety. It has been successfully demonstrated in wind farms for smooth power output and has broad application prospects in the vast new energy field, such as wind power, photovoltaic power, and smart grids. In the production of electrolytes for vanadium redox flow batteries, the stack unit is the carrier device for the circulation of electrolyte within the battery. It plays a role in sealing and regulating the flow of electrolyte within the battery, significantly impacting the charging performance of the electrolyte.

[0003] One of the core components of a flow battery stack is the bipolar plate. The bipolar plate plays a crucial role in flow batteries, effectively isolating the anode and cathode to prevent short circuits and electrolyte mixing, ensuring stable battery output. Furthermore, by connecting multiple cells, it increases the battery's output voltage, thereby improving overall battery performance without increasing the size and weight of individual cells. In addition, the selection of bipolar plate materials, electrochemical properties, and structural design are extremely stringent. They must meet requirements such as corrosion resistance, good sealing, good conductivity, and electrolyte compatibility. Their surface morphology and activity also affect the battery's electrochemical reactions. Therefore, the design and optimization of bipolar plates are of great significance for improving the performance and stability of flow batteries and promoting the development of new energy technologies.

[0004] Chinese invention patent application number 202410809219.X discloses a flow battery bipolar plate and a flow battery bipolar plate assembly, which is prepared by forming interdigitated flow channels on both sides of a flexible graphite plate. The flexible graphite plate is a 1-3 mm thick flexible graphite plate obtained by roll forming, and its constituent material includes resin. The branch flow channels of the interdigitated flow channels on both sides are staggered, with a depth of 0.3-1 mm, a width of 0.5-1 mm, and a spacing of 0.25-3 mm. The depth of the branch flow channels does not exceed 1 / 2 of the thickness of the flexible graphite plate, and the spacing between the branch flow channels is not less than 1 / 2 of the width of the branch flow channels. This bipolar plate aims to improve the exchange of electrolyte in the flow battery through the newly designed interdigitated flow channels. However, the sealing performance of this structure still has defects. The main problem is that when multiple bipolar plate assemblies are stacked together, the surrounding bolts will cause deformation of the plate when tightened, which is a common problem in stacked battery stack units. Utility Model Content

[0005] The purpose of this invention is to provide a bidirectional current-collecting electrode plate that overcomes the shortcomings of the prior art. A pressure balance hole is set in the middle of the electrode area of ​​the plate to reduce leakage caused by plate deformation after multiple electrode plates are stacked and pressurized. This makes the electrolyte flow channel in the guide groove of the electrode area smoother, the electrolyte flow field more uniform, and improves the efficiency of electrolyte production.

[0006] To achieve the above objectives, this utility model employs the following technical solution:

[0007] A bidirectional current collector electrode plate includes a plate body, an electrode area for contacting an electrode is provided in the middle of both sides of the plate body, four electrolyte passage holes are provided at the four corners of the plate body, a flow guiding groove is provided in the electrode area between the four electrolyte passage holes, the surface of the electrode area of ​​the plate body is recessed to form a space for accommodating the electrode, at least one pressure balancing hole is provided in the space, a pressure bearing platform is provided around the pressure balancing hole, and an annular sealing groove is provided on the pressure bearing platform.

[0008] Furthermore, the plate can be any one of a square, rectangle, circle, or ellipse.

[0009] Furthermore, the electrolyte passage holes on both sides of the plate are respectively provided with liquid flow guide platforms. The two liquid flow guide platforms at diagonal positions on the same side surface have the same structure. The side of the liquid flow guide platform is provided with a through hole, which is connected to the flow guide groove in the electrode area.

[0010] Furthermore, the flow guiding groove includes two parallel main guide grooves and a sub-guide groove connecting the two main guide grooves.

[0011] Furthermore, at least one of the guide grooves has a cross-section that is rectangular, semi-circular, or semi-elliptical.

[0012] Furthermore, the sub-guide grooves are symmetrically distributed between the upper and lower main guide grooves.

[0013] Furthermore, the plate body is provided with at least two rings of diaphragm sealing grooves on the outside of the electrolyte passage holes.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] 1) By setting pressure balance holes in the middle of the electrode area of ​​the plate, the plate is subjected to more uniform force, which effectively reduces the leakage problem caused by plate deformation after multiple electrode plates are stacked and pressurized. This solves the technical problem that stacked battery stack units are prone to leakage and helps to improve the corrosion problem of acidic electrolyte to the environment.

[0016] 2) The plate deformation is small, which makes the electrolyte flow channel in the electrode area guide groove more balanced and smooth, and the electrolyte flow field is uniform, which can significantly improve the efficiency of electrolyte production for vanadium redox flow batteries. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0018] Figure 2 yes Figure 1 Rear view;

[0019] Figure 3 yes Figure 1 Sectional view along line AA;

[0020] Figure 4 This is a three-dimensional structural diagram of an embodiment of the present utility model;

[0021] In the figure: 1-plate, 2-electrode area, 3-pressure balance hole, 4-pressure bearing platform, 5-sealing groove, 6-fluid flow guide platform, 7-main guide groove, 8-sub-guide groove, 9-diaphragm sealing groove, 10-through hole, 11-electrolyte passage hole, 12-metal electrode sheet. Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of this utility model. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0024] The components of the present invention described and shown in the specific embodiments herein can be arranged and designed in numerous different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but only to illustrate selected embodiments of the invention.

[0025] See Figure 1-4This is a schematic diagram of an embodiment of a bidirectional current-collecting electrode plate according to this utility model. It includes a plate body 1, with an electrode region 2 for contacting the electrode located in the middle of both sides of the plate body 1. Four electrolyte passage holes 11 are located at the four corners of the plate body 1. A flow-guiding groove is provided within the electrode region 2 between the four electrolyte passage holes 11. The surface of the electrode region 2 of the plate body 1 is recessed to form a space to accommodate the electrode. At least one pressure balancing hole 3 is provided within the electrode region 2. A pressure-bearing platform 4 is provided around the pressure balancing hole 3, and an annular sealing groove 5 is provided on the pressure-bearing platform 4. An O-ring can be installed in the sealing groove 5 to achieve a seal. A long bolt passes through the pressure balancing hole 3 for auxiliary installation of the stacked fuel cell unit. A metal electrode sheet 12 is connected to the plate body 1, embedded in the plate body 1 and communicating with the positive or negative electrode side. The plate body 1 is generally filled using carbon composite material compression molding, injection molding, and casting processes to achieve low-cost one-step molding, which has already achieved large-scale application.

[0026] The plate 1 can be any of the following shapes: square, rectangle, circle, or ellipse, to achieve various appearance designs for fuel cell stack unit products.

[0027] Each of the two side plates 1 has a liquid flow guide platform 6 on its electrolyte passage hole 11. Two diagonally opposite liquid flow guide platforms 6 on the same side surface have identical structures, allowing either the positive or negative electrolyte to enter. Positive electrolyte flows through one side surface, and negative electrolyte flows through the other. A through hole 10 is provided on the side of each liquid flow guide platform 6, connecting to a flow-guiding groove within the electrode region 2. The flow-guiding groove includes two parallel main guide channels 7 and branch guide channels 8 connecting the two main guide channels 7. Positive electrolyte flows in through one electrolyte passage hole, flows evenly through the entire electrode region 2 along an adjacent main guide channel 7 and each branch guide channel 8, and finally flows out through the other main guide channel 7 and the diagonally opposite electrolyte passage hole. At least one branch guide channel 8 has a cross-section that is rectangular, semi-circular, or semi-elliptical. The primary function of the branch guide channel 8 is to support the electrode plate, with secondary function being to allow electrolyte passage.

[0028] The sub-guide grooves 8 are symmetrically distributed between the upper and lower main guide grooves 7 to ensure the product's strength is balanced.

[0029] On plate 1, at least two diaphragm sealing grooves 9 are provided on the outer side of the electrolyte passage holes. When adjacent plates are connected, a rubber sealing ring is provided in the middle. After external pressure is applied, the rubber sealing ring deforms and embeds into the diaphragm sealing groove, which increases the sealing performance of the rubber sealing ring and has a positioning function to prevent the rubber sealing ring from stretching and deforming under pressure, thus affecting the external quality of the fuel cell stack. The sealing grooves 5 and diaphragm sealing grooves 9 are both provided on the same side of plate 1. After multiple plates are stacked, the sealing requirements can be met.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A bidirectional current-collecting electrode plate, comprising a plate body, an electrode area for contacting an electrode is provided in the middle of both side surfaces of the plate body, four electrolyte passage holes are provided at the four corners of the plate body, and a flow-guiding groove is provided in the electrode area between the four electrolyte passage holes, characterized in that, The surface of the electrode area of ​​the plate is recessed to form a space for accommodating the electrode. At least one pressure balance hole is provided in the space. A pressure bearing platform is provided around the pressure balance hole, and an annular sealing groove is provided on the pressure bearing platform.

2. The bidirectional current collector plate according to claim 1, characterized in that, The plate can be any one of a square, rectangle, circle, or ellipse.

3. A bidirectional current collector electrode plate according to claim 1, characterized in that, The electrolyte passage holes on both sides of the plate are respectively provided with liquid flow guide platforms. The two liquid flow guide platforms at opposite corners on the same side surface have the same structure. The side of the liquid flow guide platform is provided with a through hole, which is connected to the flow guide groove in the electrode area.

4. A bidirectional current collector electrode plate according to claim 3, characterized in that, The flow guide groove includes two parallel main guide grooves and a branch guide groove connecting the two main guide grooves.

5. A bidirectional current collector electrode plate according to claim 4, characterized in that, At least one of the guide grooves has a cross-section that is rectangular, semi-circular, or semi-elliptical.

6. A bidirectional current collector electrode plate according to claim 4, characterized in that, The sub-guide grooves are symmetrically distributed between the upper and lower main guide grooves.

7. A bidirectional current collector electrode plate according to claim 1, characterized in that, The plate body has at least two rings of diaphragm sealing grooves on the outside of the electrolyte passage holes.

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