High-power all-vanadium redox flow battery stack and assembly method

Abstract

The invention relates to the technical field of redox flow battery stacks, in particular to a high-power all-vanadium redox flow battery stack and an assembly method. Comprising bipolar plates, a first liquid flow frame, a diaphragm and a second liquid flow frame, end plates are arranged on the outer sides of the two bipolar plates at the outermost ends, electrodes are arranged in the first liquid flow frame and the second liquid flow frame, fixing devices corresponding to the electrodes are arranged on the diaphragm, and a connecting device and a liquid flow system are arranged between the two end plates. The electrode is fixed through the fixing device, so that the electrolyte solution can flow through the electrode more quickly, and the power output of the galvanic pile is improved through the quick flowing of the electrolyte solution. After the electrode is fixed by the fixing device, the reaction uniformity of the electrode can be increased, the concentration distribution uniformity of current and reaction substances is ensured, the internal resistance change can be reduced, and the overall performance stability, reliability and maintainability of the electric pile are improved, so that the electric pile is ensured to efficiently and stably output power in different application scenes; the requirements of large-scale energy storage and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery stacks, and in particular to a high-power all-vanadium liquid flow battery stack and an assembly method thereof. Background Art

[0002] With the rapid development of renewable energy, the demand for large-scale energy storage technology is growing. As a new type of energy storage technology, all-vanadium liquid flow battery has the advantages of independent design of power and capacity, high safety, and long life. It has been used in large-scale wind energy, solar energy, thermal power and other energy storage fields. However, the existing all-vanadium liquid flow battery stacks are difficult to meet the needs of high-power application scenarios in terms of power output.

[0003] At present, the flow rate of the electrolyte and the stability of the electrode assembly have an important impact on the power output of the all-vanadium liquid flow battery stack. Increasing the flow rate of the electrolyte can improve the mass transfer effect of the electrolyte on the electrode surface, increase the supply of active substances, and improve the power output of the stack. However, when the flow rate of the electrolyte increases, the flow pressure of the electrolyte will increase accordingly. Since the electrodes are usually made of relatively soft materials such as carbon felt and graphite felt, the flow pressure of the electrolyte will impact on the electrodes, causing the electrodes to deform, and the electrode deformation will affect the performance and life of the stack.

[0004] Therefore, how to ensure the flow rate of the electrolyte and the stability of the electrode assembly to improve the power output of the all-vanadium liquid flow battery stack is a problem that technicians in this field need to solve urgently. Summary of the invention

[0005] In order to ensure the flow rate of the electrolyte and the stability of the electrode assembly and thus improve the power output of the all-vanadium liquid flow battery stack, the present application provides a high-power all-vanadium liquid flow battery stack and an assembly method.

[0006] The present application provides a high-power all-vanadium liquid flow battery stack and an assembly method using the following technical solutions: First aspect A high-power all-vanadium liquid flow battery stack comprises a plurality of groups of bipolar plates, a first liquid flow frame, a diaphragm and a second liquid flow frame stacked in sequence, a bipolar plate being stacked on the second liquid flow frame at the outermost end, end plates being arranged on the outer sides of the two outermost bipolar plates, electrodes being arranged inside the first liquid flow frame and the second liquid flow frame, fixing devices being arranged on the diaphragm corresponding to the electrodes, a connecting device for connecting all the bipolar plates, the first liquid flow frame and the second liquid flow frame together being arranged between the two end plates, and a liquid flow system being arranged between the two end plates and being circulated and connected with the first liquid flow frame and the second liquid flow frame respectively.

[0007] Furthermore, the fixing device comprises a positioning column, the positioning column is fixedly and sealingly connected to the diaphragm, the electrode is provided with a positioning hole corresponding to the positioning column, the positioning column is detachably connected to a pressing sleeve, and the electrode is provided with a countersunk hole corresponding to the pressing sleeve.

[0008] Furthermore, there are multiple positioning posts, and the multiple positioning posts are distributed in a rectangular shape corresponding to the shape of the electrodes.

[0009] Furthermore, the connecting device includes a plurality of tie rods, and the bipolar plate, the first liquid flow frame, the second liquid flow frame and the end plate are each provided with a plurality of first mounting through holes along the outer edges. The tie rods penetrate the bipolar plate, the first liquid flow frame, the second liquid flow frame and the end plate through the first mounting through holes, and the outer ends of the tie rods penetrating the two end plates are both screwed with nuts.

[0010] Furthermore, the liquid flow system includes a first output tube, a second output tube and a first input tube, a second input tube symmetrically connected on the end plate, and four second mounting through holes are respectively provided on the bipolar plate, the first liquid flow frame, and the second liquid flow frame corresponding to the first output tube, the second output tube and the first input tube, and the second input tube, a liquid flow hole is provided on the end plate corresponding to the second mounting through hole, a liquid guide groove connected to the second mounting through hole is provided on the first liquid flow frame and the second liquid flow frame, a shunt tube passing through the bipolar plate, the first liquid flow frame, and the second liquid flow frame is sealed inside the second mounting through hole, and a shunt groove is provided on the shunt tube corresponding to the liquid guide groove.

[0011] Furthermore, the end of the symmetrically arranged first output pipe away from the end plate is connected by a first three-way pipe joint, the end of the symmetrically arranged second output pipe away from the end plate is connected by a second three-way pipe joint, the end of the symmetrically arranged first input pipe away from the end plate is connected by a third three-way pipe joint, and the end of the symmetrically arranged second input pipe away from the end plate is connected by a fourth three-way pipe joint. The first three-way pipe joint is connected to the first main output pipe, the second three-way pipe joint is connected to the second main output pipe, the third three-way pipe joint is connected to the first main input pipe, and the fourth three-way pipe joint is connected to the second main input pipe.

[0012] Furthermore, the first main output pipe is connected to a first liquid storage tank, the second main output pipe is connected to a second liquid storage tank, the first main input pipe is connected to a first delivery pump, the first delivery pump is connected to the first liquid storage tank, the second main input pipe is connected to a second delivery pump, the second delivery pump is connected to the second liquid storage tank, and the first liquid storage tank and the second liquid storage tank respectively store an anode electrolyte solution and a cathode electrolyte solution.

[0013] Second aspect A method for assembling a high-power all-vanadium liquid flow battery stack comprises the following steps: S1. Prepare materials and tools; S2, preliminary assembly of independent assembly units; S3, using sealant to fix and seal the independent assembly unit on the first liquid flow frame or the second liquid flow frame; S4, using a connecting device to sequentially install a plurality of bipolar plates, a first liquid flow frame, and a second liquid flow frame between two end plates by using a sealant to form an assembly module; S5. Install the fluid flow system on the assembly module accordingly; S6, injecting electrolyte into the liquid flow system and the assembly module, and performing exhaust treatment; S7. Perform performance test on the assembled battery stack.

[0014] Furthermore, S2 includes: S21, symmetrically passing the fixing device through the diaphragm, and forming a fixed sealing connection between the fixing device and the diaphragm; S22. The two electrodes are fixedly mounted on the fixing devices located on both sides of the diaphragm.

[0015] Furthermore, S7 includes: S71. Use a voltmeter and an ammeter to perform voltage and current tests on the assembled battery stack; S72, testing the charging and discharging efficiency of the battery stack; S73. Conduct a long-term operation test on the fuel cell stack to observe changes in the performance of the fuel cell stack.

[0016] Beneficial effects achieved: This application uses a fixing device to fix the electrode so that the electrolyte solution can flow through the electrode more quickly, and the rapid flow of the electrolyte solution increases the power output of the battery stack. After the fixing device fixes the electrode, it can not only increase the reaction uniformity of the electrode and ensure the uniform distribution of current and reaction material concentration; it can also reduce mechanical damage and prevent corrosion, and extend the life of the electrode; it can also reduce the change of internal resistance, improve the overall performance stability, reliability and maintainability of the battery stack, thereby ensuring that the battery stack can output power efficiently and stably in different application scenarios, and meet the needs of large-scale energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0018] Figure 2 It is a partial cross-sectional structural schematic diagram of an embodiment of the present application.

[0019] Figure 3 It is a structural schematic diagram of a first cross-sectional direction of an embodiment of the present application.

[0020] Figure 4 It is a schematic diagram of the structural decomposition of an embodiment of the present application.

[0021] Figure 5 It is a schematic diagram of the pipeline connection structure of a liquid flow system in an embodiment of the present application.

[0022] Figure 6 It is a schematic diagram of the structural decomposition of the bipolar plate, the first liquid flow frame, the second liquid flow frame and the end plate in one embodiment of the present application.

[0023] Figure 7 It is a schematic diagram of the structural decomposition of an independent assembly unit in an embodiment of the present application.

[0024] Figure 8 It is a schematic diagram of the internal structure of a fixing device in one embodiment of the present application.

[0025] Fig. 9 It is a structural schematic diagram of the second cross-sectional direction of an embodiment of the present application.

[0026] Description of reference numerals: 100, bipolar plate; 200, first liquid flow frame; 300, diaphragm; 400, second liquid flow frame; 500, end plate; 600, electrode; 700, fixing device; 701, positioning column; 7011, screw column; 7012, nut column; 7013, external thread; 7014, internal thread; 7015, sealing gasket; 7016, driving hole; 702, positioning hole; 703, pressing sleeve; 704, countersunk hole; 800, connecting device; 801, pull rod; 802, first mounting through hole; 803, nut; 900, liquid flow system; 901, first output pipe; 902, first mounting through hole; 9 ...1, first output pipe; 902, first mounting through hole; 903, nut; 900, liquid flow system; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 901, first output pipe; 02, second output pipe; 903, first input pipe; 904, second input pipe; 905, second mounting through hole; 906, liquid flow hole; 907, liquid guide groove; 908, shunt pipe; 909, shunt groove; 910, first three-way pipe joint; 911, second three-way pipe joint; 912, third three-way pipe joint; 913, fourth three-way pipe joint; 914, first total output pipe; 915, second total output pipe; 916, first total input pipe; 917, second total input pipe; 918, first liquid storage tank; 919, second liquid storage tank; 920, first delivery pump; 921, second delivery pump. DETAILED DESCRIPTION

[0027] The following is combined with Figure 1-9 This application is described in further detail.

[0028] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0030] The embodiments of the present application disclose a high-power all-vanadium liquid flow battery stack and an assembly method.

[0031] Example 1 Please refer to Figures 1 to 9 In one embodiment of the present application, a high-power all-vanadium liquid flow battery stack includes several groups of bipolar plates 100, a first liquid flow frame 200, a diaphragm 300, a second liquid flow frame 400, an end plate 500, an electrode 600, a fixing device 700, a connecting device 800, and a liquid flow system 900.

[0032] Please refer to Figures 1 to 9 In a specific embodiment of the present application, a plurality of groups of bipolar plates 100, a first liquid flow frame 200, a diaphragm 300, and a second liquid flow frame 400 are stacked in sequence, and a bipolar plate 100 is stacked on the outermost second liquid flow frame 400. The diaphragm 300 is fixedly and sealedly installed between the first liquid flow frame 200 and the second liquid flow frame 400. Both sides of the diaphragm 300 are located inside the first liquid flow frame 200 and the second liquid flow frame 400 and are both installed with electrodes 600. The electrodes 600 are fixedly installed inside the first liquid flow frame 200 and the second liquid flow frame 400 through a fixing device 700. The electrodes 600 are electrically connected to the bipolar plates 100 correspondingly. The outer sides of the two bipolar plates 100 at the outermost ends are both installed with end plates 500. A connecting device 800 is provided between the two end plates 500, and the connecting device 800 is fixedly and sealedly connected together with all the bipolar plates 100, the first liquid flow frame 200, and the second liquid flow frame 400. The liquid flow system 900 is cyclically connected to the first liquid flow frame 200 and the second liquid flow frame 400 through two end plates 500 .

[0033] During the working process, after the electrode 600 is fixed by the fixing device 700, it can not only increase the reaction uniformity of the electrode 600 and ensure the uniform distribution of current and reaction material concentration; it can also reduce mechanical damage and prevent corrosion, and extend the life of the electrode 600; it can also reduce the internal resistance change, and improve the overall performance stability, reliability and maintainability of the battery stack, thereby ensuring that the battery stack can output power efficiently and stably in different application scenarios and meet the needs of large-scale energy storage.

[0034] During operation, the liquid flow system 900 can circulate the positive electrolyte solution and the negative electrolyte solution in the first liquid flow frame 200 and the second liquid flow frame 400, respectively. With the fixing device 700 fixing the electrode 600, the positive electrolyte solution and the negative electrolyte solution can flow through the electrode 600 more quickly.

[0035] First, the rapid flow of the positive electrode electrolyte solution and the negative electrode electrolyte solution can ensure that the surface of the electrode 600 is continuously replenished with fresh electrolyte solution, making the exchange of reactants between the electrode 600 and the electrolyte more rapid, thereby accelerating the electrochemical reaction rate and improving the power output of the battery stack.

[0036] Secondly, the rapid flow of the positive electrode electrolyte solution and the negative electrode electrolyte solution also helps to eliminate the concentration polarization phenomenon on the surface of the electrode 600. When the electrolyte solution flows slowly, the concentration of the substances participating in the reaction on the surface of the electrode 600 will gradually decrease, while the concentration of the reaction products will gradually increase, which will hinder the further progress of the reaction and reduce the battery performance. The electrolyte solution that flows quickly through the electrode 600 can take away the reaction products in time and replenish the reaction substances, so that the concentration on the surface of the electrode 600 is always maintained in a relatively stable state, which is also conducive to improving the power output of the battery stack.

[0037] In addition, the electrolyte solution can take away the heat generated by the reaction of the electrode 600 during operation during the rapid flow process, thereby reducing the temperature inside the battery stack. A suitable temperature environment is very important for the stable performance and power output of the battery stack. Excessive temperature will lead to problems such as increased internal resistance of the battery and decreased performance of the electrode material. Therefore, the fast-flowing electrolyte solution also helps to maintain good heat dissipation of the battery stack and ensure its power output.

[0038] Please refer to Figures 1 to 9In a specific embodiment of the present application, the fixing device 700 includes a positioning column 701, the positioning column 701 is fixedly sealed and connected to the diaphragm 300, the electrode 600 is provided with a positioning hole 702 corresponding to the positioning column 701, the positioning column 701 is detachably connected with a press sleeve 703, and the electrode 600 is provided with a countersunk hole 704 corresponding to the press sleeve 703. By using the press sleeve 703, not only can the electrode 600 be fixedly installed on the positioning column 701, but the positioning column 701 can also support the diaphragm 300, which increases the structural stability of the diaphragm 300 and the electrode 600 during the working process. On the one hand, the working performance of the diaphragm 300 is guaranteed, which is conducive to extending the service life of the diaphragm 300, and effectively blocks the mixing of positive and negative electrolytes, which is conducive to preventing short circuits and ensuring safety in use. On the other hand, it also improves the reaction efficiency of the electrode 600, reduces the maintenance cost of the electrode 600, and is conducive to enhancing the reliability of the battery. The stable electrode 600 structure can also promote the efficient electrochemical reaction and reduce the frequent maintenance caused by structural damage. Therefore, the design of the fixture 700 improves the performance, life and reliability of the all-vanadium liquid flow battery, ensures that the all-vanadium liquid flow battery has more advantages in fields such as large-scale energy storage, and provides strong support for the development of sustainable energy.

[0039] Please refer to Figures 1 to 9 In a specific embodiment of the present application, there are multiple positioning posts 701, and the shapes of the multiple positioning posts 701 corresponding to the electrodes 600 are distributed in a rectangular shape. The multiple positioning posts 701 can stably support and position the electrodes 600 from multiple directions by adopting a rectangular distribution method, ensuring that the electrodes 600 will not be displaced during operation, thereby maintaining the stability of the structure of the electrodes 600 and improving the reaction efficiency. In addition, multi-point support can make the electrode 600 more evenly stressed, avoiding deformation or damage of the electrode 600 caused by excessive local pressure, which is beneficial to extending the service life of the electrode 600. Furthermore, the design of the multiple positioning posts 701 corresponding to the shapes of the electrodes 600 in a rectangular distribution helps to quickly and accurately position the electrodes 600 during the assembly process, thereby improving the efficiency of assembly. At the same time, for the all-vanadium liquid flow battery stack, the stable position of the electrode 600 helps to ensure the uniform flow of the electrolyte solution on the electrode 600, further improving the performance and reliability of the battery.

[0040] Please refer to Figures 1 to 9In a specific embodiment of the present application, the positioning column 701 includes a screw column 7011 and a nut column 7012. After the screw column 7011 pierces the diaphragm 300, it is screwed together with the nut column 7012 for threaded connection, so that the diaphragm 300 can be clamped between the screw column 7011 and the nut column 7012. A sealing gasket 7015 is arranged between the screw column 7011 and the nut column 7012 and the diaphragm 300. The sealing gasket 7015 can prevent the screw column 7011 and the nut column 7012 from causing wear or damage to the diaphragm 300 during the screwing process, and can also ensure the sealing performance between the screw column 7011 and the nut column 7012 and the diaphragm 300 after the installation is completed.

[0041] Please refer to Figures 1 to 9 In a specific embodiment of the present application, the outer side surfaces of the screw column 7011 and the nut column 7012 are both provided with external threads 7013, and the inner side surface of the pressing sleeve 703 is provided with internal threads 7014 corresponding to the external threads 7013. The end surface of the pressing sleeve 703 is provided with a driving hole 7016 for driving the rotation thereof. The pressing sleeve 703 can be conveniently driven to rotate by using a special wrench or needle-nosed pliers through the driving hole 7016. During the rotation process, the pressing sleeve 703 can be installed on the screw column 7011 and the nut column 7012 by using the external threads 7013 and the internal threads 7014.

[0042] It is understandable that in other specific embodiments of the present application, the connection between the screw column 7011 and the nut column 7012 and the pressing sleeve 703 can also be achieved by interference fit, welding, gluing, or other connection methods.

[0043] Please refer to Figures 1 to 9 In a specific embodiment of the present application, the connecting device 800 includes a plurality of tie rods 801, and threads are provided on the outer side of the tie rods 801 near the two ends thereof. The bipolar plate 100, the first liquid flow frame 200, the second liquid flow frame 400 and the end plate 500 are provided with a plurality of first mounting through holes 802 along the outer edges. During assembly, the tie rods 801 can pass through the bipolar plate 100, the first liquid flow frame 200, the second liquid flow frame 400 and the end plate 500 through the first mounting through holes 802, and then the outer ends of the tie rods 801 passing through the two end plates 500 are driven by the mounting nuts 803 to clamp the bipolar plate 100, the first liquid flow frame 200 and the second liquid flow frame 400 together, so that the battery stack of the all-vanadium liquid flow battery can be quickly assembled, which is beneficial to improving the assembly efficiency.

[0044] Please refer to Figures 1 to 9In a specific embodiment of the present application, the liquid flow system 900 includes a first output pipe 901, a second output pipe 902 and a first input pipe 903, a second input pipe 904 symmetrically connected to the end plate 500, and four second mounting through holes 905 are respectively provided on the bipolar plate 100, the first liquid flow frame 200, and the second liquid flow frame 400 corresponding to the first output pipe 901, the second output pipe 902 and the first input pipe 903, the second input pipe 904, a liquid flow hole 906 is provided on the end plate 500 corresponding to the second mounting through hole 905, a liquid guide groove 907 connected to the second mounting through hole 905 is provided on the first liquid flow frame 200 and the second liquid flow frame 400, and a shunt pipe 908 that runs through the bipolar plate 100, the first liquid flow frame 200, and the second liquid flow frame 400 is sealed and connected inside. A shunt groove 909 is provided on the shunt pipe 908 corresponding to the liquid guide groove 907.

[0045] During operation, the electrolyte solution can be double-entered and double-exited at both ends of the shunt tube 908 by using the symmetrically arranged first output tube 901, second output tube 902, first input tube 903, and second input tube 904, so that the pressure balance of the electrolyte solution at various locations inside the shunt tube 908 can be improved, so that the flow rate and pressure of the electrolyte solution through each shunt slot 909 are the same. The first output tube 901, second output tube 902, first input tube 903, and second input tube 904 can be connected to the shunt tube 908 through four second mounting through holes 905, and the corresponding electrolyte can be circulated in the corresponding first liquid flow frame 200 and second liquid flow frame 400 by using the shunt slot 909 on the shunt tube 908.

[0046] Please refer to Figures 1 to 9 In a specific embodiment of the present application, the end of the symmetrically arranged first output pipe 901 away from the end plate 500 is connected by a first three-way pipe joint 910, the end of the symmetrically arranged second output pipe 902 away from the end plate 500 is connected by a second three-way pipe joint 911, the end of the symmetrically arranged first input pipe 903 away from the end plate 500 is connected by a third three-way pipe joint 912, and the end of the symmetrically arranged second input pipe 904 away from the end plate 500 is connected by a fourth three-way pipe joint 913. The first three-way pipe joint 910 is connected to a first main output pipe 914, the second three-way pipe joint 911 is connected to a second main output pipe 915, the third three-way pipe joint 912 is connected to a first main input pipe 916, and the fourth three-way pipe joint 913 is connected to a second main input pipe 917.

[0047] During operation, the electrolyte solution can be simultaneously outputted from the symmetrically arranged first output pipe 901 through the first three-way pipe joint 910 by using the first main output pipe 914; the electrolyte solution can be simultaneously outputted from the symmetrically arranged second output pipe 902 through the second three-way pipe joint 911 by using the second main output pipe 915. The electrolyte solution can be simultaneously inputted into the symmetrically arranged first input pipe 903 through the third three-way pipe joint 912 by using the first main input pipe 916; and the electrolyte solution can be simultaneously inputted into the symmetrically arranged second input pipe 904 through the fourth three-way pipe joint 913 by using the second main input pipe 917.

[0048] Please refer to Figures 1 to 9 In a specific embodiment of the present application, the first main input pipe 916 is connected to the first liquid storage tank 918, and the second main input pipe 917 is connected to the second liquid storage tank 919; the first main output pipe 914 is connected to the first delivery pump 920, and the first delivery pump 920 is connected to the first liquid storage tank 918, and the second main output pipe 915 is connected to the second delivery pump 921, and the second delivery pump 921 is connected to the second liquid storage tank 919. The first liquid storage tank 918 and the second liquid storage tank 919 store the anode electrolyte solution and the cathode electrolyte solution, respectively.

[0049] During operation, the electrolyte solution in the battery stack can be pumped into the first liquid storage tank 918 through the first main output pipe 914 by using the first delivery pump 920, and the electrolyte solution in the first liquid storage tank 918 will be input into the symmetrically arranged first input pipe 903 through the first main input pipe 916, and the electrolyte in the first input pipe 903 will be input into the battery stack for circulation; the electrolyte solution in the battery stack can be pumped into the second liquid storage tank 919 through the second main output pipe 915 by using the second delivery pump 921, and the electrolyte solution in the second liquid storage tank 919 will be input into the symmetrically arranged second input pipe 904 through the second main input pipe 917, and the electrolyte in the second input pipe 904 will be input into the battery stack for circulation. This design uses an extraction method to extract the electrolyte from the battery stack, which can reduce the direct impact of the electrolyte solution on the electrode 600 while ensuring the flow rate of the electrolyte solution.

[0050] Example 2 Please refer to Figures 1 to 9 In one embodiment of the present application, a method for assembling a high-power all-vanadium liquid flow battery stack specifically comprises the following steps: S1. Prepare materials and tools.

[0051] S11. Prepare a corresponding number of bipolar plates 100, a first liquid flow frame 200, a diaphragm 300, a second liquid flow frame 400, electrodes 600, a fixing device 700, and an electrolyte solution according to the power required by the design.

[0052] S12 , selecting a connecting device 800 of corresponding length according to the number of bipolar plates 100 , first liquid flow frames 200 , and second liquid flow frames 400 .

[0053] S13, prepare two end plates 500 and the pipes and pipe connectors required for the fluid flow system 900.

[0054] S14. Prepare sealant and wrench for assembly.

[0055] S2. Preliminary assembly of independent assembly units.

[0056] S21, the fixing device 700 symmetrically penetrates the diaphragm 300, and the fixing device 700 and the diaphragm 300 form a fixed sealing connection, S22 , fixing the two electrodes 600 on the fixing devices 700 located on both sides of the diaphragm 300 respectively.

[0057] S3. The independent assembly unit is fixedly sealed and installed on the first liquid flow frame 200 or the second liquid flow frame 400 by using a sealant.

[0058] S4, using the connecting device 800 to sequentially install the plurality of bipolar plates 100, the first liquid flow frame 200, and the second liquid flow frame 400 between the two end plates 500 in a fixed and sealed manner using a sealant to form an assembly module; S5, installing the fluid system 900 on the assembly module accordingly; S6, injecting electrolyte into the liquid flow system 900 and the assembly module, and performing exhaust treatment; S61, slowly introduce the electrolyte solution into the liquid flow system 900, and inject it into the assembly module through the liquid flow system 900, with an injection speed of 5-10 ml / min. During the injection process, pay attention to controlling the injection amount to avoid bubbles and leakage.

[0059] S62, placing the assembly module after the electrolyte solution is injected on a vibration table for vibration exhaust treatment, with a vibration frequency of 50-60 Hz and a vibration time of 10-15 minutes.

[0060] S7. Perform performance test on the assembled battery stack.

[0061] S71. Use a voltmeter and an ammeter to test the voltage and current of the assembled battery stack. The test conditions are: temperature 25℃, pressure 0.1MPa, flow rate 10-20ml / min. Through the test, the open circuit voltage of a single battery stack is 1.0-1.5V, the operating voltage is 0.8-1.6V, and the current density is 50-100mA / cm².

[0062] S72. Test the charging and discharging efficiency of the battery stack, and calculate the charging and discharging efficiency of the battery stack by measuring the input power and output power of the battery stack. The test results show that the energy efficiency of the battery stack is 90-95%.

[0063] S73. Perform a long-term operation test on the battery stack to observe the performance changes of the battery stack. After 1,000 cycles of charge and discharge tests, the capacity retention rate of the battery stack is 85-90%, indicating that the battery stack has good stability and reliability.

[0064] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-power all-vanadium liquid flow battery stack, characterized in that: The invention comprises a plurality of groups of bipolar plates (100), a first liquid flow frame (200), a diaphragm (300), and a second liquid flow frame (400) which are stacked in sequence, wherein another bipolar plate (100) is stacked on the second liquid flow frame (400) at the outermost end, an end plate (500) is arranged on the outer sides of the two bipolar plates (100) at the outermost ends, an electrode (600) is arranged inside the first liquid flow frame (200) and the second liquid flow frame (400), a fixing device (700) is arranged on the diaphragm (300) corresponding to the electrode (600), a connecting device (800) for connecting all the bipolar plates (100), the first liquid flow frame (200), and the second liquid flow frame (400) together is arranged between the two end plates (500), and a liquid flow system (900) which is cyclically connected to the first liquid flow frame (200) and the second liquid flow frame (400) is arranged between the two end plates (500); The fixing device (700) comprises a positioning column (701), the positioning column (701) is fixedly and sealingly connected to the diaphragm (300), the electrode (600) is provided with a positioning hole (702) corresponding to the positioning column (701), the positioning column (701) is detachably connected to a pressing sleeve (703), and the electrode (600) is provided with a countersunk hole (704) corresponding to the pressing sleeve (703).

2. A high-power all-vanadium liquid flow battery stack according to claim 1, characterized in that: There are a plurality of positioning posts (701), and the plurality of positioning posts (701) are distributed in a rectangular shape corresponding to the shape of the electrode (600).

3. A high-power all-vanadium liquid flow battery stack according to claim 1, characterized in that: The connecting device (800) comprises a plurality of tie rods (801); a plurality of first mounting through holes (802) are provided along the outer edges of the bipolar plate (100), the first liquid flow frame (200), the second liquid flow frame (400) and the end plate (500); the tie rods (801) pass through the bipolar plate (100), the first liquid flow frame (200), the second liquid flow frame (400) and the end plate (500) through the first mounting through holes (802); and nuts (803) are screwed onto the outer ends of the tie rods (801) passing through the two end plates (500).

4. A high-power all-vanadium liquid flow battery stack according to claim 1, characterized in that: The liquid flow system (900) comprises a first output pipe (901), a second output pipe (902) and a first input pipe (903), a second input pipe (904) symmetrically connected to the end plate (500); the bipolar plate (100), the first liquid flow frame (200), and the second liquid flow frame (400) are provided with four second mounting through holes (905) corresponding to the first output pipe (901), the second output pipe (902) and the first input pipe (903), the second input pipe (904); the end plate (50 0) is provided with a liquid flow hole (906) corresponding to the second mounting through hole (905), the first liquid flow frame (200) and the second liquid flow frame (400) are both provided with a liquid guide groove (907) connected to the second mounting through hole (905), the second mounting through hole (905) is sealed inside with a shunt pipe (908) passing through the bipolar plate (100), the first liquid flow frame (200), and the second liquid flow frame (400), and the shunt pipe (908) is provided with a shunt groove (909) corresponding to the liquid guide groove (907).

5. A high-power all-vanadium liquid flow battery stack according to claim 4, characterized in that: One end of the symmetrically arranged first output pipe (901) away from the end plate (500) is connected by a first three-way pipe joint (910), one end of the symmetrically arranged second output pipe (902) away from the end plate (500) is connected by a second three-way pipe joint (911), one end of the symmetrically arranged first input pipe (903) away from the end plate (500) is connected by a third three-way pipe joint (912), one end of the symmetrically arranged second input pipe (904) away from the end plate (500) is connected by a fourth three-way pipe joint (913), the first three-way pipe joint (910) is connected to a first main output pipe (914), the second three-way pipe joint (911) is connected to a second main output pipe (915), the third three-way pipe joint (912) is connected to a first main input pipe (916), and the fourth three-way pipe joint (913) is connected to a second main input pipe (917).

6. A high-power all-vanadium liquid flow battery stack according to claim 5, characterized in that: The first main output pipe (914) is connected to a first liquid storage tank (918), the second main output pipe (915) is connected to a second liquid storage tank (919), the first main input pipe (916) is connected to a first delivery pump (920), the first delivery pump (920) is connected to the first liquid storage tank (918), the second main input pipe (917) is connected to a second delivery pump (921), the second delivery pump (921) is connected to the second liquid storage tank (919), and the first liquid storage tank (918) and the second liquid storage tank (919) respectively store an anode electrolyte solution and a cathode electrolyte solution.

7. A method for assembling a high-power all-vanadium liquid flow battery stack, characterized in that: The following steps are involved: S1. Prepare materials and tools; S2, preliminary assembly of independent assembly units; S3, using a sealant to fix and seal the independent assembly unit onto the first liquid flow frame (200) or the second liquid flow frame (400); S4, using a connecting device (800), the plurality of bipolar plates (100), the first liquid flow frame (200), and the second liquid flow frame (400) are sequentially fixedly and sealedly installed between two end plates (500) using a sealant to form an assembly module; S5, installing the fluid flow system (900) on the assembly module accordingly; S6, injecting electrolyte into the liquid flow system (900) and the assembly module, and performing exhaust treatment; S7. Perform performance test on the assembled battery stack.

8. The method for assembling a high-power all-vanadium liquid flow battery stack according to claim 7, characterized in that: The S2 includes: S21, the fixing device (700) is symmetrically passed through the diaphragm (300), and the fixing device (700) and the diaphragm (300) are fixedly sealed and connected; S22, fixing the two electrodes (600) on the fixing devices (700) located on both sides of the diaphragm (300) respectively.

9. The method for assembling a high-power all-vanadium liquid flow battery stack according to claim 7, characterized in that: The S7 includes: S71. Use a voltmeter and an ammeter to perform voltage and current tests on the assembled battery stack; S72, testing the charging and discharging efficiency of the battery stack; S73. Conduct a long-term operation test on the fuel cell stack to observe changes in the performance of the fuel cell stack.

Images