Battery proton membrane welded to plate frame using mussel adhesion factor

Abstract

The application discloses a battery proton membrane and plate frame welding method using a mussel adhesion factor welding diaphragm, the welding method comprising the following steps: firstly, welding a welding diaphragm between the proton membrane and the plate frame to realize the close welding of the proton membrane and the plate frame; and then welding a layer of mussel adhesion factor welding diaphragm above the proton membrane, so that the adhesion of the welding diaphragm caused by water absorption of the proton membrane is avoided, the technical problem that the proton membrane is prone to falling off is solved, the close welding connection of the proton membrane and the plate frame is realized, the welding seam is precise and firm, the welding seam is not permeable to air and water, the sealing performance is good, the vibration stress and the thermal stress generated in the welding process of the plate frame are greatly reduced, the service life of the proton membrane and the plate frame is prolonged, the processing efficiency is high, the situation that the electrolyte of the flow battery leaks due to permeation is effectively avoided, the reliability of the flow battery is improved, the service life of the flow battery is prolonged, and the application prospect is excellent.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser welding, in particular to a method for welding a proton membrane of a battery and a plate frame using a mussel adhesion factor. BACKGROUND

[0002] Flow battery energy storage technology has the characteristics of environmental friendliness, independent adjustment of power and energy, etc., and has broad application prospects in large-scale energy storage systems. At present, technologies such as all-vanadium flow battery, iron-chromium flow battery and zinc-bromine flow battery have been successfully developed. A typical flow battery system is composed of an electric pile, two pumps and two anode electrolyte and cathode liquid tanks. The basic unit of the electric pile is a single cell, which is composed of two bipolar plates, two electrodes and a membrane. The proton membrane separates the anode and the cathode in the battery and provides a proton conduction path. In order to ensure that the electrolyte does not leak, there must be no gap between the edges of all the components in contact, and they must be well sealed. Therefore, a welded membrane is used to weld the proton membrane and the plate frame.

[0003] Laser welding is a high-efficiency and precise welding method using a high-energy density laser beam as a heat source. Through an optical system, the laser beam is focused on a very small area, forming a heat source area with high energy concentration in a very short time, so that the welded object is melted and forms a firm welding point and welding seam.

[0004] In the prior art, the welding technology of the proton membrane and the plate frame has not been maturely developed. Direct welding is difficult to find a plate frame material with a melting point close to that of the perfluorosulfonic acid ion membrane and can ensure environmental applicability and economy. Therefore, there is no good sealing form for direct welding of the two. At present, if only single-layer welding is used, the adhesion of the welded membrane will be poor due to the water absorption of the proton membrane after welding, which will easily cause leakage. Moreover, the service life of the flow battery is as long as 15 to 25 years, and after the continuous circulation of the electrolyte, the adhesion of the welded membrane will be poor, which cannot meet the requirements of the existing flow battery. Therefore, a new way of welding the proton membrane and the plate frame together is needed to improve the waterproofness and sealing of the welded membrane. SUMMARY

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and solve the problems of high sealing costs and easy leakage caused by the proton exchange membrane absorbing water, which leads to the loss of adhesion of the welded separator. This invention provides a method for welding the proton exchange membrane to the plate and frame using a mussel adhesion factor welded separator. The welding method includes first welding the proton exchange membrane to the plate and frame using a welded separator to achieve a tight weld. Then, another layer of mussel adhesion factor welded separator is welded on top of the proton exchange membrane, avoiding the loss of adhesion of the welded separator due to water absorption by the proton exchange membrane, thus solving the technical problem of easy proton exchange membrane detachment. This achieves a tight welded connection between the proton exchange membrane and the plate and frame. This welding method produces precise, strong, airtight, and watertight welds with excellent sealing performance. It greatly reduces the vibration and thermal stress generated in the plate and frame during welding, extends the service life of the proton exchange membrane and the plate and frame, has high processing efficiency, effectively avoids electrolyte leakage in flow batteries, improves the reliability of flow batteries, extends the service life of flow batteries, and has excellent application prospects.

[0006] To achieve the above technical effects, the following technical solution is adopted:

[0007] A method for welding the proton exchange membrane to the plate and frame of a battery using mussel adhesion factors includes the following steps:

[0008] Step S1: Selection of laser welding system: Based on the transmission and reflection characteristics of the laser to the plate frame and glass plate materials and the beam characteristics of different lasers, select a laser welding machine and use a PC-controlled three-dimensional worktable to control the movement direction of the workpiece to be welded and the welding head.

[0009] Step S2: In a dust-free environment, the proton exchange membrane, the welding diaphragm, and the bottom light-transmitting plate frame are stacked together in sequence, with the proton exchange membrane on the top layer, the bottom light-transmitting plate frame on the bottom layer, the welding diaphragm placed in the middle layer between the two, and a glass plate placed on top, with a downward force applied.

[0010] Step S3: The laser welding machine emits an infrared laser. The laser passes through the bottom light-transmitting plate frame and concentrates the energy on the welding diaphragm. The welding diaphragm is heated by the laser temperature, the temperature of the bottom light-transmitting plate frame rises, the welding diaphragm in the middle layer melts, and the adhesion of the welding diaphragm is stimulated, so that the proton exchange membrane and the bottom light-transmitting plate frame are fused together.

[0011] Step S4: Attach the mussel adhesion factor welding diaphragm to the already welded proton exchange membrane, with the position corresponding to the previous welding diaphragm attachment position. Place a glass plate on top and apply a downward force.

[0012] Step S5: the laser energy is concentrated on the mussel adhesion factor welding diaphragm through the glass plate from above, the mussel adhesion factor welding diaphragm is heated by the laser temperature, the mussel adhesion factor welding diaphragm is melted, the adhesion of the mussel adhesion factor welding diaphragm is excited, and the mussel adhesion factor welding diaphragm is fully bonded with the proton membrane and integrated; the proton membrane and the plate frame are welded;

[0013] The preparation method of the mussel adhesion factor is:

[0014] After the metal salt and the high molecular polymer are mixed, vibration is carried out in a constant temperature water bath oscillator for 30 min, and the reaction is fully completed when standing for 2 h; then, the mussel adhesion factor is fully mixed with an excess of a reducing curing agent, then carbon black is added and the carbon black is fully mixed with the excess of the reducing curing agent, the light absorption of the mixture is increased, and then drying and curing are carried out at 100 DEG C to obtain the biomimetic mussel adhesion glue on the glass plate.

[0015] Specifically, the high molecular polymer is L-DOPA, a catechol structure dopa adhesion protein, the mass of the L-DOPA is 4-6 g; the metal salt is a CuCl2 solution with a concentration of 0.05 mL / L, and the amount used is 2-3 mL; the reducing curing agent is a styrene and butadiene block copolymer rubber, the mass of the styrene is 10 mL, and the mass of the butadiene block copolymer rubber is 3-4 g; the amount of the carbon black used is 1-2 g.

[0016] Further, in step S1, a semiconductor continuous laser is selected for the laser welding machine, the wavelength is 808-980 nm, the laser is a semiconductor continuous welding device, a PC is used to control a three-dimensional workbench, the workpiece to be welded moves in the X and Y directions, and the welding head moves in the Z direction.

[0017] Further, the mussel adhesion factor welding diaphragm, the welding diaphragm and the bottom light-transmitting plate frame are wiped with anhydrous ethanol before step S2.

[0018] Further, the wavelength of the semiconductor continuous laser in step S1 is 915-980 nm.

[0019] Further, the downward force applied by the glass plate in steps S2 and S4 is 0.3-0.5 MPa; and the proton membrane is selected from a perfluorosulfonic acid resin membrane.

[0020] Further, the thickness of the welding diaphragm in step S3 is 0.08-0.4 mm; the welding power between the plate frame and the welding diaphragm is 50-100 W; and the welding rate is 2-20 mm / s.

[0021] Further, the thickness of the welding diaphragm in step S3 is 0.25 mm; and the light transmittance of the bottom light-transmitting plate frame is above 30%.

[0022] Due to the water absorption characteristics of the proton membrane, such as perfluorosulfonic acid resin membrane, a layer of mussel adhesion factor welding diaphragm is welded on the proton membrane.

[0023] Further, the thickness of the mussel adhesion factor welding diaphragm in step S4 is 0.08-0.1 mm; the surface of the mussel adhesion factor welding diaphragm is coated with a layer of waterproof film; the thickness of the waterproof film is 0.01±0.005 mm.

[0024] Further, the material of the welding diaphragm in step S2 adopts the mussel adhesion factor welding diaphragm in step S4.

[0025] Further, the welding power between the mussel adhesion factor welding diaphragm and the proton membrane in step S5 is 10-200 W, and the welding speed is 2-20 mm / s.

[0026] The present application has the following advantages:

[0027] The welding method disclosed in the present application comprises welding a layer of welding diaphragm between the proton membrane and the plate frame to realize the tight welding of the proton membrane and the plate frame, and then welding a layer of mussel adhesion factor welding diaphragm above the proton membrane, which avoids the disappearance of the adhesion of the welding diaphragm due to the water absorption of the proton membrane, solves the technical problem of easy falling of the proton membrane, and realizes the tight welding connection of the proton membrane and the plate frame. The mussel adhesion factor in the mussel adhesion factor welding diaphragm is a high-viscosity biomimetic material that imitates the adhesion of clams to rocks in water, and the mussel adhesion factor has waterproof properties and strong adhesion. The welding method has precise and firm welding seams, is not breathable and does not leak water, has good sealing performance, greatly reduces the vibration stress and thermal stress generated in the welding process of the plate frame, prolongs the service life of the proton membrane and the plate frame, has high processing efficiency, effectively avoids the penetration and leakage of electrolyte in the flow battery, improves the reliability of the flow battery, prolongs the service life of the flow battery, and has excellent application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. The drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the provided drawings.

[0029] Figure 1 The welding diaphragm structure in the embodiments of the present application is shown in the figure;

[0030] Figure 2 The mussel adhesion factor welding diaphragm structure in the embodiments of the present application is shown in the figure;

[0031] Figure 3 A structural schematic diagram of a welding finished product in an embodiment of the present application;

[0032] Figure 4 A structural schematic diagram of a welding finished product in an embodiment of the present application;

[0033] 1 is a welding diaphragm; 2 is a welding diaphragm of a mussel adhesion factor; 3 is a proton membrane perfluorosulfonic acid resin film; 4 is a bottom light-transmitting plate frame; and 5 is a waterproof PET film on the surface of the welding diaphragm of the mussel adhesion factor. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not intended to limit the present application.

[0035] It should be pointed out that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0036] It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and in addition, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of a feature, step, operation and / or combination thereof.

[0037] Example 1:

[0038] The embodiment of the present application provides a liquid flow battery proton membrane and plate frame laser welding method using a mussel adhesion factor welding diaphragm, comprising the following steps:

[0039] First, a semiconductor continuous laser is selected for welding, with a wavelength of 980 nm. The laser is a semiconductor continuous welding device, and a PC is used to control a three-dimensional workbench. The welded workpiece moves in the X and Y directions, and the welding head moves in the Z direction.

[0040] Use 75% alcohol to wipe the welding diaphragm 1 as shown in Figure 1 , the mussel adhesion factor welding diaphragm 2 as shown in Figure 2 , and the bottom light-transmitting plate frame 4.

[0041] Place a clean bottom light-transmitting plate frame 4 (light transmittance above 30%) on the platform, and paste the welding diaphragm 1 with a thickness of 0.08-0.4 mm along the designed track. An automatic film sticking machine can be used to improve efficiency.

[0042] like Figure 3 As shown, the proton exchange membrane perfluorosulfonic acid resin membrane 3 is laid flat on top of the welding diaphragm 1. A mechanical gripper can be used for automatic gripping and feeding to improve accuracy and efficiency. Then, the plate frame with the welding diaphragm 1 and proton exchange membrane perfluorosulfonic acid resin membrane 3 pasted on is flipped over for transmission laser welding to improve welding adhesion. Alternatively, the plate frame can be left unflipped, with a glass plate placed on top and a downward force of 0.3 MPa applied. The welding machine is then started at 50W power and a speed of 20 mm / s. Under the lifting action of the cylinder, the glass plate presses down to apply a pressure of 0.3 MPa. After laser welding, the welding diaphragm 1 heats the bottom transparent plate frame 4 through the laser temperature, melting the upper welding diaphragm and stimulating its adhesion. This allows the proton exchange membrane perfluorosulfonic acid resin membrane 3 and the bottom transparent plate frame 4 to fuse together as a welded product. A pressure hold of 15 seconds is applied after welding to improve adhesion and sealing.

[0043] A layer of mussel adhesion factor welding diaphragm 2 (0.08-0.1 mm thick) is then glued to the upper surface of the proton exchange membrane perfluorosulfonic acid resin membrane 3 in the first welded product. The mussel adhesion factor in the welding diaphragm 2 is a biomimetic material with high viscosity in water, similar to how clams adhere to rocks. The mussel adhesion factor has waterproof properties and strong adhesion. Similarly, an automatic film applicator can be used for application. The surface of the mussel adhesion factor welding diaphragm 2 is coated with a 0.01 mm thick waterproof PET film 5.

[0044] The preparation method of the mussel adhesion factor is as follows:

[0045] After mixing the metal salt with the polymer, the mixture is vibrated in a constant temperature water bath shaker for 30 minutes and allowed to stand for 2 hours to allow the reaction to be fully completed. Then, it is thoroughly mixed with an excess of reducing curing agent, and then carbon black is added and thoroughly mixed with the excess reducing curing agent to increase the light absorption of the mixture. After drying and curing at 100°C, the biomimetic mussel adhesive is obtained by coating it on a glass plate.

[0046] Specifically: the polymer is L-DOPA, a dopa adhesion protein with a catechol structure, with a mass of 4-6g; the metal salt is a 0.05mL / L CuCl2 solution, used in a volume of 2-3mL; the reducing curing agent is a styrene and butadiene block copolymer rubber, with a styrene mass of 10ml and a butadiene block copolymer rubber mass of 3-4g; and the carbon black content is 1-2g.

[0047] The mussel adhesion factor in the welded diaphragm is a biomimetic material with high viscosity in water, similar to how clams adhere to rocks. The mussel adhesion factor has waterproof properties and strong adhesion.

[0048] Place the finished product 2 (with the mussel adhesion agent welded diaphragm) on the welding machine table, and place a glass plate on top, with the placement relationship as follows: Figure 4 As shown, the welding machine is then started, and laser welding (welding power 10-200W, welding speed 2-20mm / s) is performed under the pressure of the glass plate (0.3MPa) as the cylinder lifts it up, resulting in the second welded product. Similarly, pressure is maintained for 15s after welding to improve adhesion and sealing.

[0049] Finally, a cooling process is performed by turning off the laser to allow the mussel adhesion factor welding diaphragm 2 to cool and solidify.

[0050] The welding diaphragm 1 described in this embodiment can be made of hot melt adhesive material, or it can be made of the same material as the welding diaphragm 2 made of mussel adhesion factor in this embodiment. The present invention does not limit this.

[0051] In summary, this invention discloses a method for welding a proton exchange membrane (PEM) to a battery frame using a mussel adhesion factor welding separator. The welding method involves first welding the PEM to the frame using a welding separator to achieve a tight weld. Then, a second layer of mussel adhesion factor welding separator is welded on top of the PEM. This avoids the loss of adhesion due to water absorption by the PEM, solving the technical problem of easy detachment of the PEM. This achieves a tight weld connection between the PEM and the frame. The weld seam produced by this method is precise, strong, airtight, and watertight, with excellent sealing performance. It significantly reduces the vibration and thermal stress generated during the welding process, extending the service life of the PEM and the frame. It also boasts high processing efficiency, effectively preventing electrolyte leakage in flow batteries, improving the reliability of flow batteries, and extending their service life, demonstrating excellent application prospects.

[0052] Therefore, those skilled in the art will recognize that although embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A method for welding a battery proton exchange membrane to a plate and frame using mussel adhesion factors, characterized in that, The method includes the following steps: Step S1: Selection of laser welding system: Based on the transmission and reflection characteristics of the laser to the plate frame and glass plate materials and the beam characteristics of different lasers, select a laser welding machine and use a PC-controlled three-dimensional worktable to control the movement direction of the workpiece to be welded and the welding head. Step S2: In a dust-free environment, the proton exchange membrane (3), the welding diaphragm (1), and the bottom light-transmitting plate frame (4) are stacked together in sequence, with the proton exchange membrane (3) on the upper layer, the bottom light-transmitting plate frame (4) on the lower layer, the welding diaphragm (1) placed in the middle layer between the two, and a glass plate placed on top, applying a downward force. Step S3: The laser welding machine emits infrared laser. The laser passes through the bottom light-transmitting plate frame (4) and concentrates the energy on the welding diaphragm (1). The welding diaphragm (1) is heated by the laser temperature. The temperature of the bottom light-transmitting plate frame (4) rises, melting the middle layer welding diaphragm (1) and stimulating the adhesion of the welding diaphragm (1), so that the proton membrane (3) and the bottom light-transmitting plate frame (4) are integrated. Step S4: Attach the mussel adhesion factor welding diaphragm (2) above the already welded proton membrane (3), with the position corresponding to the previous welding diaphragm (1) pasting position. Place a glass plate on top and apply a downward force. Step S5: The laser passes through the glass plate from above and concentrates the energy on the mussel adhesion factor welding diaphragm (2). The temperature of the mussel adhesion factor welding diaphragm (2) is increased by the laser temperature, and the mussel adhesion factor welding diaphragm (2) melts, stimulating the adhesion of the mussel adhesion factor welding diaphragm (2), so that the mussel adhesion factor welding diaphragm (2) and the proton exchange membrane (3) are fully bonded and fused together; the welding of the proton exchange membrane and the plate frame is completed. The preparation method of the mussel adhesion factor is as follows: After mixing the metal salt with the polymer, the mixture is vibrated in a constant temperature water bath shaker for 30 minutes and allowed to stand for 2 hours to allow the reaction to be fully completed. Then, it is thoroughly mixed with an excess of reducing curing agent, and then carbon black is added and thoroughly mixed with the excess reducing curing agent to increase the light absorption of the mixture. After drying and curing at 100°C, the biomimetic mussel adhesive is obtained by coating it on a glass plate. Specifically: the polymer is L-DOPA, a dopa adhesion protein with a catechol structure, with a mass of 4-6g; the metal salt is a 0.05mL / L CuCl2 solution, used in 2-3mL amounts; the reducing curing agent is a styrene and butadiene block copolymer rubber, with a styrene mass of 10ml and a butadiene block copolymer rubber mass of 3-4g; and the carbon black content is 1-2g. In steps S2 and S4, the downward force applied to the glass plate is 0.3~0.5 MPa; the proton exchange membrane (3) is a perfluorosulfonic acid resin membrane; In step S5, the welding power between the mussel adhesion factor welding diaphragm (2) and the proton membrane (3) is 10-200W and the welding speed is 2-20mm / s.

2. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, In step S1, the laser welding machine uses a semiconductor continuous laser with a wavelength of 808-980nm. The laser is a semiconductor continuous welding device, and a three-dimensional worktable is controlled by a PC. The workpiece to be welded moves in the X and Y directions, and the welding head moves in the Z direction.

3. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, Before step S2, the mussel adhesion factor welding diaphragm (2), welding diaphragm (1) and bottom light-transmitting plate frame (4) are wiped with anhydrous ethanol and then set aside for use.

4. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, In step S1, the wavelength of the semiconductor continuous laser is 915~980nm.

5. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, In step S3, the thickness of the welding diaphragm (1) is 0.08~0.4mm; the welding power between the plate frame and the welding diaphragm (1) is 50~100W; and the welding speed is 2~20mm / s.

6. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, The thickness of the welding diaphragm (1) in step S3 is 0.25 mm; the light transmittance of the bottom light-transmitting plate frame (4) is above 30%.

7. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, In step S4, the thickness of the mussel adhesion factor welding diaphragm (2) is 0.08~0.1mm; the surface of the mussel adhesion factor welding diaphragm (2) is coated with a waterproof PET film (5); the thickness of the waterproof PET film (5) is 0.01±0.005mm.

8. The battery proton exchange membrane and plate / frame welding method using mussel adhesion factor to weld the separator as described in claim 1, characterized in that, The material of the welding diaphragm (1) in step S2 is the same as that of the mussel adhesion factor welding diaphragm (2) in step S4.

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