Integrated structure of electrode frame and bipolar plate and liquid flow energy storage battery

Abstract

According to the integrated structure of the electrode frame and the bipolar plate and the liquid flow energy storage battery provided by the utility model, after the bipolar plate is subjected to injection molding, the electrode frame is directly subjected to injection molding on the bipolar plate, so that the electrode frame and the bipolar plate are connected to form the integrated structure with good sealing performance, and a sealing gasket between the bipolar plate and the electrode frame can be omitted; on the premise that half of the sealing elements are reduced, the sealing effect can be improved to prevent electrolyte leakage, the overall thickness of the galvanic pile can be reduced, the overall size of the flow energy storage battery can be reduced, and the ohmic internal resistance of the flow energy storage battery can be reduced to improve the energy efficiency of the flow energy storage battery. Moreover, the electrode frame is directly formed on the bipolar plate through injection molding, and the electrode frame and the bipolar plate are integrally formed and sealed, so that compared with a processing mode that the electrode frame is welded on the bipolar plate through laser, the assembly process flow of the electrode frame and the bipolar plate can be simplified, and the assembly efficiency of the electrode frame and the bipolar plate is effectively improved; and rapid and large-scale mass production is easy to realize.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy storage batteries, and in particular relates to an integrated structure of an electrode frame and a bipolar plate and a liquid flow energy storage battery. Background Art

[0002] Among various energy storage batteries, liquid flow batteries offer broad application prospects for large-scale energy storage due to their many advantages, including independent output power and capacity, flexible system design, high energy efficiency, stable and reliable operation, and high safety. In practical applications, liquid flow batteries typically require multiple single-cell structures to be assembled in series to form a stack. A single cell typically includes bipolar plates, gaskets, electrode frames, electrodes, and a separator. Each cell requires four gaskets to prevent leakage.

[0003] Currently, laser welding is also used to achieve an integrated seal between the electrode frame and bipolar plate. However, while laser welding can achieve a seal between the electrode frame and bipolar plate without the need for sealing materials, its low welding efficiency leads to low production efficiency, making rapid and large-scale mass production impossible. Furthermore, adding flow channel structures to traditional bipolar plates requires cutting the flow channel plate separately and then gluing it to the bipolar plate, which is not only complex but also results in excessive material waste. Utility Model Content

[0004] Based on the above-mentioned problems existing in the prior art, the purpose of the embodiments of the present invention is to provide an integrated structure of an electrode frame and a bipolar plate, so as to solve the problem in the prior art that the electrode frame and the bipolar plate are integrated into a sealed structure by laser welding, but the production efficiency is low and rapid and large-scale mass production cannot be achieved.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is to provide an integrated structure of an electrode frame and a bipolar plate, comprising:

[0006] A bipolar plate having a plate-like structure, wherein a flow channel structure for transporting electrolyte to the reaction layer of the electrode is provided on the bipolar plate, and the bipolar plate is injection molded; and

[0007] an electrode frame having an opening, wherein the electrode frame is stacked on a side of the bipolar plate having the flow channel structure, and the opening is arranged corresponding to the flow channel structure;

[0008] The electrode frame is injection molded on the bipolar plate so that the electrode frame and the bipolar plate form an integrated structure.

[0009] Furthermore, the bipolar plate is a first injection-molded part injection-molded by a double-material injection mold, and the electrode frame is a second injection-molded part injection-molded on the bipolar plate by a double-material injection mold.

[0010] Furthermore, the flow channel structure is an interdigitated flow channel injection-molded on the bipolar plate.

[0011] Furthermore, the electrode frame is injection molded on one side of the bipolar plate.

[0012] Furthermore, a snap-fitting protrusion is injection-molded on the bipolar plate, and a snap-fitting groove for receiving the snap-fitting protrusion is injection-molded on the electrode frame.

[0013] Furthermore, the number of the clamping protrusions and the clamping grooves is set to be multiple, the clamping protrusions and the clamping grooves are provided in a one-to-one correspondence, and each of the clamping protrusions is embedded in the corresponding clamping groove.

[0014] Furthermore, the bipolar plate is provided with a tab, and the tab extends to the outside of the electrode frame.

[0015] Furthermore, the thickness of the electrode frame is 2 to 5 mm.

[0016] Furthermore, the bipolar plate has a thickness of 0.6 to 5 mm.

[0017] Another purpose of the embodiments of the present invention is to provide a liquid flow energy storage battery to solve the problem in the prior art of using laser welding to integrate the electrode frame and bipolar plate into a sealed package, which cannot be quickly and mass-produced due to low production efficiency.

[0018] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a liquid flow energy storage battery, including the integrated structure of the electrode frame and bipolar plate provided by any of the above-mentioned embodiments.

[0019] Compared with the prior art, the one or more technical solutions in the embodiments of the present invention have at least one of the following beneficial effects:

[0020] The integrated structure of the electrode frame and bipolar plate in the embodiment of the present invention allows the electrode frame to be directly injection-molded onto the bipolar plate after the bipolar plate is injection-molded. This allows the electrode frame and bipolar plate to be connected to form a well-sealed integrated structure, eliminating the need for a gasket between the bipolar plate and the electrode frame. This reduces the number of sealing components by half, not only improving the sealing effect to prevent electrolyte leakage, but also reducing the overall thickness of the battery stack, reducing the overall volume of the liquid flow energy storage battery, and reducing the ohmic internal resistance of the liquid flow energy storage battery, thereby improving its energy efficiency. Furthermore, by directly injection-molding the electrode frame onto the bipolar plate, the electrode frame and bipolar plate are integrated and sealed. Compared to laser welding of the electrode frame to the bipolar plate, this simplifies the assembly process of the electrode frame and bipolar plate, effectively improving the assembly efficiency of the electrode frame and bipolar plate, and facilitating rapid and large-scale mass production.

[0021] In the embodiment of the present invention, an injection molding process is used to directly injection mold the finger-type flow channel on the bipolar plate, which can overcome the waste of bipolar plate materials, complex process, and burrs, flanging, and uneven defects that occur on the cut edges of the bipolar plate due to the need to cut the finger-type flow channel structure and then bond it to the bipolar plate in the existing bipolar plate preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 An assembly diagram of the integrated structure of the electrode frame and bipolar plate provided in an embodiment of the present utility model;

[0024] Figure 2 An exploded view of the integrated structure of the electrode frame and bipolar plate provided in an embodiment of the present utility model;

[0025] Figure 3 A schematic structural diagram of a bipolar plate provided in an embodiment of the present utility model;

[0026] Figure 4 A cross-sectional view of the integrated structure of the electrode frame and bipolar plate provided in an embodiment of the present utility model;

[0027] Figure 5 A cross-sectional view of an electrode frame provided in an embodiment of the present utility model.

[0028] Among them, the reference numerals in the figures are:

[0029] 1- bipolar plate; 11- flow channel structure; 12- clamping protrusion; 13- pole ear;

[0030] 2-electrode frame; 21-mouth; 22-clamping groove; 23-positive electrode liquid inlet; 24-negative electrode liquid inlet; 25-positive electrode liquid outlet; 26-negative electrode liquid outlet; 27-liquid inlet main channel; 28-liquid outlet main channel. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] It should be noted that when an element is referred to as being "connected to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined. In the description of this utility model, it should be noted that, unless otherwise specified or defined, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can mean fixed, removable, or integral; mechanical or electrical; direct or indirect through an intermediary; internal communication between two elements; or interaction between two elements. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0033] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, when the phrases "in one embodiment," "in some embodiments," or "in some embodiments" appear in various places throughout this specification, not all references are to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0034] Please also refer to Figures 1 to 4, the integrated structure of the electrode frame and the bipolar plate provided in the embodiment of the present invention is now described. The integrated structure of the electrode frame and the bipolar plate provided in the embodiment of the present invention includes a bipolar plate 1 and an electrode frame 2. The bipolar plate 1 is a plate-like structure. The bipolar plate 1 is injection molded by an injection molding process. The bipolar plate 1 is provided with a flow channel structure 11 for transporting the electrolyte to the reaction layer of the electrode. The center position of the electrode frame 2 is provided with a mouth 21. The electrode frame 2 is stacked on the side of the bipolar plate 1 having the flow channel structure 11, and the mouth 21 is arranged corresponding to the flow channel structure 11. Specifically, the electrode frame 2 is injection molded on the bipolar plate 1, so that the electrode frame 2 and the bipolar plate 1 are fused to form an integrated structure, thereby achieving a sealing effect. The flow channel structure 11 on the bipolar plate 1 is a finger-type flow channel injection molded on the bipolar plate 1. By directly forming the finger-shaped flow channels on the bipolar plate 1 through injection molding, the existing process of preparing finger-shaped bipolar plates 1 requires cutting the flow channel structure and then bonding it to the flat bipolar plate 1, resulting in wasteful bipolar plate 1 material, complex manufacturing processes, and the tendency for burrs, flanging, and unevenness to form on the cut edges of the bipolar plate 1. Furthermore, the finger-shaped flow channels significantly improve the flow field structure on the bipolar plate 1, ensuring more uniform electrolyte flow across the electrode regions of the bipolar plate 1.

[0035] The integrated structure of the electrode frame and bipolar plate provided in the present embodiment, compared to the prior art, allows the electrode frame 2 to be directly injection molded onto the bipolar plate 1 after the bipolar plate 1 is injection molded, thereby forming an integrated structure with excellent sealing performance. This eliminates the need for a gasket between the bipolar plate 1 and the electrode frame 2. While reducing the number of sealing elements by half, this not only improves the sealing effect to prevent electrolyte leakage, but also reduces the overall thickness of the battery stack, shrinks the overall volume of the liquid flow energy storage battery, and reduces the ohmic internal resistance of the liquid flow energy storage battery, thereby improving its energy efficiency. Furthermore, by directly injection molding the electrode frame 2 onto the bipolar plate 1, the electrode frame 2 and bipolar plate 1 are integrated and sealed. Compared to the laser welding method of the electrode frame 2 to the bipolar plate 1, this method simplifies the assembly process of the electrode frame 2 and bipolar plate 1, effectively improves the assembly efficiency of the electrode frame 2 and bipolar plate 1, and facilitates rapid and large-scale mass production.

[0036] In some embodiments, the bipolar plate 1 is a first injection-molded part formed by injection molding a mixture of graphite, carbon fiber, and resin, wherein the mixture comprises 2% to 7% carbon fiber, 40% to 50% resin, and the remainder flexible graphite worm powder. The electrode frame 2 is a second injection-molded part formed on the bipolar plate 1 by injection molding polypropylene or polyethylene. The bipolar plate 1 with the flow channel structure 11 can be first injection-molded using an injection mold, and then the electrode frame 2 can be injection-molded onto the bipolar plate 1 using an injection mold. This allows the bipolar plate 1 and the electrode frame 2 to be well connected together, thereby achieving a good sealing effect and improving the assembly efficiency of the bipolar plate 1 and the electrode frame 2. In addition, the electrode frame 2 is injection-molded on a single side of the bipolar plate 1, which can facilitate contact between the bipolar plate 1 and other unit stacks and reduce contact resistance. This is because the battery modules of existing battery stacks are usually assembled into a battery module by several single batteries, and then multiple battery modules are assembled into a battery stack. The bipolar plate 1 is injection-molded on one side of the electrode frame 2. When the battery modules are assembled with each other, the outermost bipolar plate 1 of the battery module can directly contact the outermost bipolar plate 1 of another battery template, thereby reducing the contact resistance.

[0037] In some embodiments, the bipolar plate 1 is a first injection-molded part injection-molded by a double-material injection mold, and the electrode frame 2 is a second injection-molded part injection-molded on the bipolar plate 1 by a double-material injection mold. The bipolar plate 1 with the flow channel structure 11 can be first injection-molded in a first mold cavity using a double-material injection mold, and then the injection-molded bipolar plate 1 is rotated or translated together with the mold into the second mold cavity of the double-material injection mold. The electrode frame 2 is injection-molded on the bipolar plate 1 in the second mold cavity using the double-material injection mold, so that the bipolar plate 1 and the electrode frame 2 can be well connected together, thereby achieving a good sealing effect while further improving the assembly efficiency of the bipolar plate 1 and the electrode frame 2.

[0038] Please refer to Figure 3 、 Figure 4 and Figure 5 In some embodiments, the bipolar plate 1 is injection-molded with a snap-fit ​​protrusion 12, and the electrode frame 2 is injection-molded with a snap-fit ​​groove 22 for receiving the snap-fit ​​protrusion 12. When the electrode frame 2 is injection-molded onto the bipolar plate 1, the snap-fit ​​protrusion 12 on the bipolar plate 1 is embedded in the snap-fit ​​groove 22 on the electrode frame 2, thereby increasing the bonding strength between the electrode frame 2 and the bipolar plate 1.

[0039] Please refer to Figure 3 、 Figure 4 and Figure 5In some embodiments, the number of the engaging protrusions 12 and the engaging grooves 22 is set to multiple, and the engaging protrusions 12 are provided in a one-to-one correspondence with the engaging grooves 22. Each engaging protrusion 12 is embedded in a corresponding engaging groove 22, which can further increase the bonding strength between the electrode frame 2 and the bipolar plate 1. Specifically, the bipolar plate 1 is provided with engaging protrusions 12 arranged in a matrix around the flow channel structure 11, and the electrode frame 2 is provided with engaging grooves 22 arranged in a matrix around the opening 21. The engaging protrusions 12 are provided in a one-to-one correspondence with the engaging grooves 22, so that each engaging protrusion 12 can be embedded in a corresponding engaging groove 22. On the one hand, this helps to increase the contact area between the bipolar plate 1 and the electrode frame 2, and on the other hand, it can enhance the stability of the bonding between the bipolar plate 1 and the electrode frame 2. It should be noted that the engaging protrusions 12 can be, but are not limited to, cylindrical protrusions, and the engaging grooves 22 can be, but are not limited to, cylindrical grooves. In addition, the height of the locking protrusion 12 is between 1 / 4 and 1 / 2 of the thickness of the electrode frame 2 .

[0040] Please refer to Figure 1 and Figure 2 In some embodiments, the electrode frame 2 is provided with a positive electrode liquid inlet 23, a negative electrode liquid inlet 24, a positive electrode liquid outlet 25 and a negative electrode liquid outlet 26 respectively. Figure 2 This is a schematic diagram of the positive electrode frame. The electrode frame 2 also features a liquid inlet channel 27 connecting the opening 21 with the positive electrode liquid inlet 23, and a liquid outlet channel 28 connecting the opening 21 with the positive electrode liquid outlet 25. The negative electrode frame is similar to the positive electrode frame, except that the negative electrode liquid inlet 24 and negative electrode liquid outlet 26 are connected to the opening 21. Furthermore, the bipolar plate 1 is provided with tabs 13 that extend outside the electrode frame 1 to facilitate subsequent testing of the single cell. Figure 2 In the embodiment, the bipolar plate 1 is provided with electrolyte inlets and outlets corresponding to the positive electrode liquid inlet 23, the negative electrode liquid inlet 24, the positive electrode liquid outlet 25, and the negative electrode liquid outlet 26. In other embodiments, the bipolar plate 1 may not be provided with electrolyte inlets and outlets, and the bipolar plate 1 may only cover the opening 21 of the electrode frame 2 and the area around the opening 21.

[0041] It should be noted that in some embodiments, the thickness of the electrode frame 2 is 2 to 5 mm, and the thickness of the bipolar plate 1 is 0.6 to 5 mm. Since the injection-molded bipolar plate 1 is thinner, the overall thickness of the battery stack can be reduced, the overall volume of the liquid flow energy storage battery can be reduced, and the ohmic internal resistance of the liquid flow energy storage battery can be reduced, thereby improving its energy efficiency.

[0042] The present invention also provides a liquid flow energy storage battery comprising the integrated electrode frame and bipolar plate structure of any of the aforementioned embodiments. Because the liquid flow energy storage battery possesses all the technical features of the integrated electrode frame and bipolar plate structure of any of the aforementioned embodiments, it achieves the same technical effects as the aforementioned integrated electrode frame and bipolar plate structure.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integrated structure of an electrode frame and a bipolar plate, characterized in that: include: The bipolar plate has a plate-like structure and is provided with a flow channel structure for transporting electrolyte to the reaction layer of the electrode. The bipolar plate is injection molded; as well as an electrode frame having an opening, wherein the electrode frame is stacked on a side of the bipolar plate having the flow channel structure, and the opening is arranged corresponding to the flow channel structure; The electrode frame is injection molded on the bipolar plate so that the electrode frame and the bipolar plate are connected to form an integrated structure.

2. The integrated structure of the electrode frame and bipolar plate according to claim 1, characterized in that: The bipolar plate is a first injection molded part injection-molded by a double-material injection mold, and the electrode frame is a second injection molded part injection-molded on the bipolar plate by a double-material injection mold.

3. The integrated structure of the electrode frame and bipolar plate according to claim 1, characterized in that: The flow channel structure is an interdigitated flow channel injection-molded on the bipolar plate.

4. The integrated structure of the electrode frame and bipolar plate according to claim 1, characterized in that: The electrode frame is injection molded on one side of the bipolar plate.

5. The integrated structure of the electrode frame and bipolar plate according to claim 1, characterized in that: A snap-fitting protrusion is injection-molded on the bipolar plate, and a snap-fitting groove for receiving the snap-fitting protrusion is injection-molded on the electrode frame.

6. The integrated structure of the electrode frame and bipolar plate according to claim 5, characterized in that: The number of the clamping protrusions and the clamping grooves is set to be multiple, the clamping protrusions and the clamping grooves are arranged in a one-to-one correspondence, and each clamping protrusion is embedded in the corresponding clamping groove.

7. The integrated structure of the electrode frame and bipolar plate according to claim 1, characterized in that: The bipolar plate is provided with a tab, and the tab extends to the outside of the electrode frame.

8. The integrated structure of the electrode frame and the bipolar plate according to any one of claims 1 to 7, characterized in that: The thickness of the electrode frame is 2 to 5 mm.

9. The integrated structure of the electrode frame and the bipolar plate according to any one of claims 1 to 7, characterized in that: The thickness of the bipolar plate is 0.6 to 5 mm.

10. A liquid flow energy storage battery, characterized in that: An integrated structure comprising an electrode frame and a bipolar plate as claimed in any one of claims 1 to 9.

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