Flow battery pole plate preparation method based on mould pressing and flow battery pole plate

Abstract

The invention relates to a flow battery pole plate preparation method based on mould pressing and a flow battery pole plate. The flow battery pole plate preparation method comprises the following steps: carrying out primary vacuumizing on an impregnation container in which a mould pressing plate formed by mould pressing is placed; injecting liquid resin into the dipping container until the liquid level of the liquid resin is higher than the top of the molded plate; vacuumizing the dipping container for the second time; pressurizing the impregnation container and maintaining the pressure for a set time to form an impregnation plate; the liquid resin in the impregnation container is discharged, and the liquid resin on the surface of the impregnation plate is cleaned after the impregnation plate is taken out; the cleaned dipping plate is subjected to water bath curing, so that resin filled in gaps of the dipping plate is cured; and drying the impregnated plate subjected to water bath curing to form the battery polar plate, and preparing the flow battery polar plate by using a mold pressing process by adopting the preparation method disclosed by the invention.

Description

Technical Field

[0001] This invention relates to the field of battery electrode technology, specifically to a method for preparing flow battery electrode plates based on molding and the flow battery electrode plate itself. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Flow battery plates are one of the core components of the battery stack, and their performance directly affects the battery's energy efficiency, power density, lifespan, and cost. Currently, flow battery plates are made using a PVDF powder mixing process. This process results in high resistivity and poor molding performance, making it unsuitable for various shapes. While current battery plates can overcome the shortcomings of the PVDF powder mixing process, this molding process has not been applied to flow battery plates. Current molding processes result in numerous pores in the plates, hindering practical application. Therefore, applying molding to the fabrication of flow battery plates is a pressing technical challenge. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing flow battery plates based on molding and flow battery plates, so that the molding process can be applied to the preparation of flow battery plates.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a method for preparing flow battery plates based on molding, comprising the following steps: The impregnation container containing the molded plate is first evacuated to remove the gas from the gaps inside the molded plate. Pour liquid resin into the impregnation container until the liquid level of the resin covers the top of the molding plate; The impregnation container is evacuated a second time to remove the gas that entered the impregnation container during the injection of liquid resin. The impregnation container is pressurized and held for a set time so that liquid resin is forced into the gaps inside the molding plate to fill the gaps and form an impregnation plate. Drain the liquid resin from the impregnation container, remove the impregnation plate, and clean the liquid resin from the surface of the impregnation plate. The cleaned impregnated board is then cured in a water bath to allow the resin filling the gaps in the impregnated board to harden.

[0006] The impregnated plate, after water bath curing, is dried to form battery plates.

[0007] Optionally, during the first vacuuming, the vacuum level inside the impregnation container shall not exceed 50 Pa, and the vacuuming time shall not be less than 1 hour.

[0008] Optionally, when injecting liquid resin into the impregnation container, the injection rate of the liquid resin shall not exceed 300 ml / s.

[0009] Optionally, during the second vacuuming, the vacuum level inside the impregnation container shall not exceed 50 Pa, and the vacuuming time shall not be less than 1 hour.

[0010] Optionally, when pressurizing the impregnation container, the pressure inside the container shall be not less than 0.5 MPa. Optionally, the pressure holding time can be set to be no less than 1 hour.

[0011] Optionally, gas can be injected into the space above the liquid resin surface of the impregnation container to pressurize the impregnation container.

[0012] Optionally, after drying, the surface of the battery plates is cleaned and burrs are removed. After removing the burrs, the battery plates are leveled. After leveling, the preparation of the flow battery plates is completed.

[0013] Optionally, the process of cleaning the liquid resin on the surface of the impregnated plate is as follows: first, the impregnated plate is immersed in a static cleaning solution for cleaning, and then the cleaned impregnated plate is immersed in flowing deionized water or purified water for rinsing.

[0014] Secondly, embodiments of the present invention provide a flow battery electrode plate, which is prepared using the flow battery electrode plate preparation method described in the first aspect.

[0015] The beneficial effects of this invention are as follows: 1. The method for preparing flow battery electrodes of the present invention involves impregnating the electrode plate in liquid resin. By impregnating the molded plate formed by molding in liquid resin, the liquid resin can fill the voids inside the molded plate, which can significantly improve the weight gain efficiency and mechanical strength of the electrode plate, reduce the porosity of the electrode plate, and make it more suitable for use in high-speed operating environments. At the same time, it provides sealing and tightness to the graphite electrode plate, so that the electrode plate will not leak when used as a flow battery electrode plate. This method realizes the preparation of flow battery electrodes using molding technology, filling the technological gap in this area.

[0016] 2. The method for preparing the electrode plate of the flow battery of the present invention, by first vacuuming, can extract the gas in the gaps inside the electrode plate, so that the liquid resin can fill the gaps inside the electrode plate. By second vacuuming, the gas that enters the impregnation container during the liquid resin injection process can be extracted. By pressurizing, the liquid resin can fill the gaps inside the electrode plate. By combining the above steps, the filling rate of the gaps inside the electrode plate by the liquid resin is guaranteed. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a flowchart of the preparation method in Embodiment 1 of the present invention. Detailed Implementation

[0019] Example 1 This embodiment provides a method for preparing flow battery electrodes based on molding, such as... Figure 1 As shown, it includes the following steps: Step 1: Molding the precast plate or powder to form a molded plate. In this embodiment, the molded plate is a graphite plate.

[0020] In this embodiment, the molding process can be carried out using existing technology. Other molding methods for battery plates can be used, and their specific details will not be described in detail here.

[0021] For example, precast panels can be molded using molding equipment, and the integrated molding mold and molding method disclosed in patent CN116278144B can be used to prepare the molded panels.

[0022] In another embodiment, a molded plate is prepared using powder. The mold includes an upper mold and a lower mold. The upper mold has a forming surface, and the lower mold has a forming surface. The upper mold and the lower mold are installed on a stamping device. The upper mold can move up and down. The powder is laid on the forming surface of the lower mold. The upper mold moves downward to mold the powder laid on the forming surface of the lower mold.

[0023] In the third embodiment, the molding surfaces of the upper mold and / or lower mold are provided with groove structures that match the flow channels on the surface of the battery electrode plates. After molding, the surface of the molding plate is provided with protrusion structures that match the groove structures, and the protrusion structures form flow channels.

[0024] When both the upper and lower molds have groove structures on their forming surfaces, flow channel structures can be formed on both sides of the molding plate. In this case, an integrally formed battery plate can be made, avoiding the defects of flow channel layer peeling and high resistance that exist in layered battery plates.

[0025] Step 2: Place the molded plate into the impregnation container.

[0026] In this embodiment, multiple molding plates are held in an impregnation cage, and the molding plates are arranged vertically. The multiple molding plates are placed into an impregnation container using the impregnation cage.

[0027] The impregnation container is an impregnation tank, which is used to introduce liquid resin to impregnate multiple molded plates.

[0028] The impregnation cage has multiple sets of parallel supports, each set of supports having multiple receiving slots with open tops for accommodating the molding plate. The same molding plate is placed vertically into the corresponding receiving slots of multiple sets of supports for support.

[0029] It is understood that the impregnation cage may also use other structural forms to support the electrode plate, which will not be described in detail here.

[0030] In another embodiment, the impregnation cage has multiple sets of supports, which are horizontally arranged and composed of multiple support rods. The support rods support the molding plates, and the multiple molding plates are immersed in the impregnation tank in a horizontal position.

[0031] Those skilled in the art can choose the immersion posture of the electrode plate in the impregnation tank according to actual needs, which will not be described in detail here.

[0032] Step 3: Perform the first vacuuming of the impregnation container.

[0033] In this embodiment, a vacuum port is provided at the top of the impregnation tank. The vacuum port is connected to a vacuum system, which includes a vacuum pump, pipelines, valves, etc. Existing technologies can be used, and will not be described in detail here.

[0034] The inside of the impregnation tank is evacuated through the vacuum port.

[0035] Preferably, the first vacuuming time is not less than 1 hour and the vacuum degree is not greater than 50 Pa. For example, the first vacuuming time is 1.5 hours and the vacuum degree is 45 Pa. By the first vacuuming, the air in the impregnation tank and the internal pores of the electrode plate can be extracted, which makes it easier for the liquid resin to fill the internal pores of the electrode plate.

[0036] It is understandable that those skilled in the art can set the first vacuuming time and vacuum level according to actual needs, and will not be described in detail here.

[0037] Step 4: Inject liquid resin into the impregnation container through the injection port.

[0038] In this embodiment, liquid epoxy resin is used as the liquid resin. Liquid epoxy resin is injected into the impregnation tank through the injection port until the liquid level of the liquid epoxy resin is higher than the top surface of the multiple electrode plates, that is, the liquid surface of the liquid epoxy resin covers the top surface of the electrode plates, so that the electrode plates are completely immersed in the liquid epoxy resin.

[0039] Preferably, the injection rate of the liquid epoxy resin is no greater than 300 ml / s. In this embodiment, the injection rate of the liquid epoxy resin is 300 ml / s. It is understood that those skilled in the art can set the injection rate of the liquid epoxy resin according to actual needs, which will not be described in detail here.

[0040] Step 5: Perform a second vacuuming on the impregnation container.

[0041] The method of this step is the same as the first vacuuming method in step 3. The second vacuuming time is not less than 1 hour, preferably 1 hour. The second vacuuming makes the vacuum degree in the impregnation tank not greater than 50 Pa. Preferably, the vacuum degree in the impregnation tank after the second vacuuming is 50 Pa. Through the second vacuuming, the air brought into the impregnation tank when injecting liquid epoxy resin can be extracted.

[0042] Step 6: Pressurize the impregnation container through the pressurization port of the impregnation container.

[0043] In this embodiment, gas is introduced into the impregnation container through the pressurization port of the impregnation tank. Preferably, air is introduced. For example, the pressurization port is connected to an air compressor through an air pipe, and the air compressor is used to pressurize the impregnation tank.

[0044] In this embodiment, gas is introduced into the impregnation tank so that the gas pressure inside the impregnation tank is not less than 0.5 MPa. In this embodiment, gas is introduced into the impregnation tank so that the gas pressure inside the impregnation tank reaches 0.5 MPa. It is understood that those skilled in the art can set the gas pressure reached by the impregnation tank after the gas is introduced according to actual needs, which will not be described in detail here.

[0045] After pressurization, the impregnation tank is held under pressure for at least 1 hour. Those skilled in the art can set the holding time according to actual needs, which will not be described in detail here.

[0046] By introducing gas to apply pressure to the liquid epoxy resin, the liquid epoxy resin can be forced into the voids inside the electrode plate, thus filling the voids inside the electrode plate with liquid epoxy resin.

[0047] Step 7: Drain the liquid epoxy resin from the impregnation container.

[0048] In this embodiment, the bottom of the impregnation tank is provided with a discharge port, through which liquid epoxy resin is discharged. The discharge speed can be set according to actual needs, and will not be described in detail here.

[0049] Step 8: Remove the multiple impregnation plates formed by the molding plate after impregnation from the impregnation tank, and then clean the surface of the impregnation plates to remove impurities and liquid epoxy resin from the electrode surface.

[0050] In this embodiment, the cleaning process includes two steps: washing and rinsing. By combining the washing and rinsing steps, it can be ensured that the liquid epoxy resin and impurities on the surface of the impregnated plate are cleaned. In this embodiment, the washing and rinsing time is 25-35 minutes, preferably 30 minutes. Those skilled in the art can set the time according to actual needs, which will not be described in detail here.

[0051] Multiple electrode plates are immersed in a static cleaning solution in a cleaning container using an immersion cage to clean the surface of the electrode plates. Any existing cleaning solution can be used, and will not be described in detail here.

[0052] The cleaned plates are immersed in flowing deionized water or purified water in a rinsing container through an impregnation cage to rinse the surface of the impregnated plates.

[0053] The cleaning and rinsing methods and equipment can be based on existing technology and will not be described in detail here.

[0054] Step 9: After cleaning, the electrode plates are placed in a water bath curing device for curing. Existing equipment can be used for water bath curing. Details are not provided here. During water bath curing, the temperature of the constant-temperature water is 80-85℃, preferably 82℃, and the curing time is 50-70 minutes, preferably 60 minutes. It can be understood that the temperature and time of water bath curing can be set according to actual needs, and will not be described in detail here.

[0055] Water bath curing is a process that uses a constant temperature water bath to control the temperature, so that the material can undergo a curing reaction at a specific and uniform temperature. Through water bath curing, the liquid epoxy resin filling the gaps in the electrode plate can be cured to achieve better mechanical strength.

[0056] In this embodiment, the epoxy resin in the gaps of the electrode plate is cured by water bath curing, which allows for precise and uniform temperature control, simpler operation, and relatively lower equipment cost.

[0057] Step 10: After cleaning, send the water-bath cured board into a drying device for drying. Any existing drying equipment can be used; details will not be provided here. The operating temperature of the drying chamber is 100-120℃, preferably 110℃, and the drying time is 25-35 minutes, preferably 30 minutes. It is understood that the drying temperature and drying time can be set according to actual needs; further details will not be provided here.

[0058] Step 11: Clean the surface of the dried battery plates and remove the burrs. This step can be done using existing processes and will not be described in detail here.

[0059] Step 12: After cleaning the surface of the battery plates, level the battery plates. The leveling method can be done using existing technology and will not be described in detail here.

[0060] Step 13: After the battery plates are leveled, laser marking is performed on the designated areas of the battery plates. After laser marking is completed, the production of the flow battery plates is finished, and the battery plates can be put into storage.

[0061] The preparation method of this embodiment involves impregnating a molded plate formed by molding into liquid epoxy resin. The liquid epoxy resin fills the gaps between the molded plates, significantly improving the weight gain efficiency and mechanical strength of the electrode, reducing its porosity, and making it more suitable for use in high-speed operating environments. Simultaneously, it provides a tight seal for the graphite electrode, preventing leakage when used as a flow battery electrode. This method realizes the preparation of flow battery electrodes using molding technology, filling a technological gap in this area. Furthermore, the first vacuuming process removes gas from the gaps inside the electrode, allowing the liquid resin to fill these gaps. The second vacuuming process removes air that enters the impregnation tank during liquid resin injection, ensuring effective filling of the gaps within the molded plate. Pressurization further ensures the liquid resin fills the gaps within the molded plate. The combined use of the first vacuuming, second vacuuming, and pressurization steps guarantees a high filling rate of the liquid resin within the molded plate.

[0062] Example 2 This embodiment provides a flow battery electrode plate, which is prepared using the molding-based flow battery electrode plate preparation method described in Embodiment 1.

[0063] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing flow battery electrodes based on molding, characterized in that, Includes the following steps: The first vacuuming is performed on the impregnation container into which the molded plate is placed; Pour liquid resin into the impregnation container until the liquid level of the resin covers the top of the molding plate; Perform a second vacuuming on the impregnation container; The impregnation container is pressurized and held for a set time so that liquid resin is forced into the gaps inside the molding plate to fill the gaps and form an impregnation plate. Drain the liquid resin from the impregnation container, remove the impregnation plate, and clean the liquid resin from the surface of the impregnation plate. The cleaned impregnated board is then cured in a water bath to allow the resin filling the gaps in the impregnated board to cure. The impregnated plate, after water bath curing, is dried to form battery plates.

2. The method for preparing flow battery plates based on molding as described in claim 1, characterized in that, During the first vacuuming, the vacuum level inside the impregnation container should not exceed 50 Pa, and the vacuuming time should not be less than 1 hour.

3. The method for preparing flow battery plates based on molding as described in claim 1, characterized in that, When injecting liquid resin into the impregnation container, the injection rate of the liquid resin shall not exceed 300 ml / s.

4. The method for preparing flow battery electrodes based on molding as described in claim 1, characterized in that, During the second vacuuming, the vacuum level inside the impregnation container should not exceed 50 Pa, and the vacuuming time should not be less than 1 hour.

5. The method for preparing flow battery electrodes based on molding as described in claim 1, characterized in that, When pressurizing the impregnation container, pressurize it until the pressure inside the impregnation container is not less than 0.5 MPa.

6. The method for preparing flow battery electrodes based on molding as described in claim 1, characterized in that, The pressure holding time should be no less than 1 hour.

7. The method for preparing flow battery plates based on molding as described in claim 1, characterized in that, Gas is injected into the space above the liquid resin surface in the impregnation container to pressurize the impregnation container.

8. The method for preparing flow battery electrodes based on molding as described in claim 1, characterized in that, After drying, the surface of the battery plates is cleaned and burrs are removed. After removing the burrs, the battery plates are leveled. After leveling, the preparation of the flow battery plates is completed.

9. The method for preparing flow battery electrodes based on molding as described in claim 1, characterized in that, The process of cleaning the liquid resin on the surface of the impregnated plate is as follows: First, the impregnated plate is immersed in a static cleaning solution for cleaning, and then the cleaned impregnated plate is immersed in flowing deionized water or purified water for rinsing.

10. A flow battery electrode plate, characterized in that, It is prepared by the molding-based flow battery electrode preparation method according to any one of claims 1-9.

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