Vanadium electrolyte electrolysis system

Abstract

The utility model discloses a vanadium electrolyte electrolysis system, include: main electrolytic part, main electrolytic part includes main electrolytic power supply and main electrolytic electric pile, protection electrolytic part, protection electrolytic part includes protection electrolytic power supply and protection electrolytic electric pile, liquid storage part, liquid storage part includes positive pole liquid storage tank and negative pole liquid storage tank, wherein, the export of positive pole liquid storage tank, first pipe line, main positive pole liquid access channel, main positive pole liquid discharge channel, second pipe line, protection positive pole liquid access channel, protection positive pole liquid discharge channel, third pipe line and the import of positive pole liquid storage tank are communicated in proper order, the export of negative pole liquid storage tank, fourth pipe line, protection negative pole liquid access channel, protection negative pole liquid discharge channel, fifth pipe line, main positive pole liquid access channel, main positive pole liquid discharge channel, sixth pipe line and the import of negative pole liquid storage tank are communicated in proper order. According to the vanadium electrolyte electrolysis system of the utility model can improve the service life of main electrolytic part.

Description

Technical Field

[0001] This utility model relates to the field of vanadium electrolyte electrolysis technology, and specifically to a vanadium electrolyte electrolysis system. Background Technology

[0002] In related technologies, electrolytic cells often employ a precision filter before electrolysis to prevent insoluble impurities in the electrolyte from contaminating the cell components. However, in actual operation, various soluble organic and inorganic substances inevitably exist in the electrolyte, which can contaminate the electrolytic cell components during operation, leading to decreased performance or even failure of the electrolytic cell, and reducing its current efficiency. Utility Model Content

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a vanadium electrolyte electrolysis system.

[0004] The vanadium electrolyte electrolysis system of this utility model embodiment includes:

[0005] The main electrolysis unit includes a main electrolysis power supply and a main electrolysis stack. The main electrolysis stack includes multiple main electrolysis cell groups. The main electrolysis stack has a main positive electrode liquid inlet channel, a main positive electrode liquid outlet channel, a main negative electrode liquid inlet channel, and a main negative electrode liquid outlet channel. The positive terminal of the main electrolysis power supply is connected to the anode current collector of the main electrolysis stack, and the negative terminal of the main electrolysis power supply is connected to the cathode current collector of the main electrolysis stack.

[0006] A protective electrolysis unit is provided, comprising a protective electrolysis power supply and a protective electrolysis stack. The protective electrolysis stack includes multiple protective electrolysis cell groups. The protective electrolysis stack has a protective positive electrode liquid inlet channel, a protective positive electrode liquid outlet channel, a protective negative electrode liquid inlet channel, and a protective negative electrode liquid outlet channel. The positive terminal of the protective electrolysis power supply is connected to the anode current collector of the protective electrolysis stack, and the negative terminal of the protective electrolysis power supply is connected to the cathode current collector of the protective electrolysis stack.

[0007] The liquid storage section includes a positive electrode liquid storage tank and a negative electrode liquid storage tank. The positive electrode liquid storage tank is used to store the positive electrode electrolyte, and the negative electrode liquid storage tank is used to store the negative electrode electrolyte.

[0008] The outlet of the positive electrode liquid storage tank, the first pipeline, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the second pipeline, the protective positive electrode liquid inlet channel, the protective positive electrode liquid outlet channel, the third pipeline, and the inlet of the positive electrode liquid storage tank are connected in sequence.

[0009] The outlet of the negative electrode liquid storage tank, the fourth pipeline, the protective negative electrode liquid inlet channel, the protective negative electrode liquid outlet channel, the fifth pipeline, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the sixth pipeline, and the inlet of the negative electrode liquid storage tank are connected in sequence.

[0010] In some embodiments, the protective electrolytic cell assembly includes a cathode plate, an anode plate, and an ion exchange membrane. The cathode plate, the ion exchange membrane, and the anode plate are arranged sequentially along a first direction. The cathode plate and the ion exchange membrane define a cathode electrolyte chamber, and the anode plate and the ion exchange membrane define an anode electrolyte chamber. The protective positive electrode liquid inlet channel and the protective positive electrode liquid outlet channel are connected to the anode electrolyte chamber, and the protective negative electrode liquid inlet channel and the protective negative electrode liquid outlet channel are connected to the cathode electrolyte chamber.

[0011] In some embodiments, the protective electrolytic cell stack further includes two end plates, a cathode insulating plate, a cathode current collector, an anode current collector, and an anode insulating plate, wherein one of the two end plates, the cathode insulating plate, the cathode current collector, the plurality of protective electrolytic cell groups, the anode current collector, the anode insulating plate, and the other of the two end plates are arranged sequentially in the first direction;

[0012] Each of the protective electrolytic cells also includes a liquid flow frame, which is provided between the ion exchange membrane and each of the anode plate and the cathode plate.

[0013] In some embodiments, the cathode electrolyte chamber is filled with cathode electrode material, and the anolyte chamber is filled with anolyte material.

[0014] In some embodiments, the thickness of the cathode electrode material is greater than or equal to 4 mm and less than or equal to 30 mm, and the compression ratio of the cathode electrode material is greater than or equal to 15% and less than or equal to 40%.

[0015] In some embodiments, the cathode electrode material includes at least one of graphite felt, carbon paper, and carbon cloth;

[0016] The anode electrode material includes at least one of a metal mesh and a metal felt.

[0017] In some embodiments, the protective electrolytic stack includes a bipolar plate, wherein the anode side and the cathode side of the bipolar plate are respectively configured to be adjacent to the anode plate and the cathode plate in the first direction, and the bipolar plate is made of a coated metal plate, a graphite plate or a flexible graphite plate.

[0018] In some embodiments, the protective electrolysis unit further includes a voltage monitor connected to a plurality of tabs on the protective electrolysis stack to detect the voltage of a plurality of protective electrolysis cell groups in the protective electrolysis stack. When the voltage of at least one of the plurality of protective electrolysis cell groups in the protective electrolysis stack is greater than or equal to 5V, the protective electrolysis stack is cleaned and repaired.

[0019] In some embodiments, both the third pipeline and the sixth pipeline include a light-transmitting observation section. When the solution inside the light-transmitting observation section of either the third pipeline or the sixth pipeline turns black, the protective electrolytic cell is cleaned and repaired.

[0020] In some embodiments, there are two protective electrolytic units;

[0021] The second pipeline is connected to the protective positive electrode liquid inlet channel of the two protective electrolysis sections through two seventh pipelines respectively, and each of the seventh pipelines is provided with a first opening and closing valve;

[0022] The protective positive electrode liquid discharge channels of the two protective electrolysis sections are respectively connected to the third pipeline through two eighth pipelines, and each of the eighth pipelines is provided with a second opening and closing valve;

[0023] The fourth pipeline is connected to the protective negative electrode liquid inlet channel of the two protective electrolysis sections through two ninth pipelines respectively, and each of the ninth pipelines is provided with a third on / off valve;

[0024] The protective negative electrode liquid discharge channels of the two protective electrolysis sections are connected to the fifth pipeline through two tenth pipelines respectively, and each of the tenth pipelines is provided with a fourth on / off valve.

[0025] The beneficial effects of this invention are as follows: The vanadium electrolyte electrolysis system according to this invention allows a relatively pure positive electrolyte to first enter the main electrolysis section for electrolysis and then enter the protective electrolysis section for further electrolysis. The negative electrolyte containing impurities first enters the protective electrolysis section for electrolysis and then enters the main electrolysis section. This allows the protective electrolysis section to absorb impurities in the negative electrolyte, resulting in less impurities in the negative electrolyte entering the main electrolysis section, thereby improving the service life of the main electrolysis section. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a vanadium electrolyte electrolysis system according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of a vanadium electrolyte electrolysis system according to another embodiment of the present invention.

[0028] Figure 3This is a schematic diagram of a voltage monitor according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of a protective electrolytic cell stack according to an embodiment of the present invention.

[0030] Figure label:

[0031] 1. Main electrolysis unit; 11. Main electrolysis power supply; 12. Main electrolysis stack;

[0032] 2. Protect the electrolysis section; 21. Protect the electrolysis power supply; 22. Protect the electrolysis stack; 221. End plate; 222. Cathode plate; 223. Anode plate; 224. Ion exchange membrane; 225. Bipolar plate; 226. Cathode insulating plate; 227. Cathode current collector; 228. Anode current collector; 229. Anode insulating plate; 230. Liquid flow frame; 23. Voltage monitor; 24. Tab;

[0033] 3. Positive electrode liquid storage tank; 31. Positive electrode liquid pump body;

[0034] 4. Negative electrode liquid storage tank; 41. Negative electrode liquid pump body;

[0035] 51. First pipeline, 52. Second pipeline, 53. Third pipeline, 54. Fourth pipeline, 55. Fifth pipeline, 56. Sixth pipeline, 57. Seventh pipeline, 58. Eighth pipeline, 59. Ninth pipeline, 60. Tenth pipeline, 61. First on / off valve, 62. Second on / off valve, 63. Third on / off valve, 64. Fourth on / off valve. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The vanadium electrolyte electrolysis system of this utility model according to an embodiment of the present invention is described below with reference to the accompanying drawings. Figures 1 to 4 As shown, the vanadium electrolyte electrolysis system according to an embodiment of the present invention includes a main electrolysis unit 1, a protective electrolysis unit 2, and a storage unit.

[0038] The main electrolysis unit 1 includes a main electrolysis power supply 11 and a main electrolysis stack 12. The main electrolysis stack 12 includes multiple main electrolysis cell groups and has a main positive electrode liquid inlet channel, a main positive electrode liquid outlet channel, a main negative electrode liquid inlet channel, and a main negative electrode liquid outlet channel. The positive terminal of the main electrolysis power supply 11 is connected to the anode current collector 228 of the main electrolysis stack 12, and the negative terminal of the main electrolysis power supply 11 is connected to the cathode current collector 227 of the main electrolysis stack 12.

[0039] The protective electrolysis unit 2 includes a protective electrolysis power supply 21 and a protective electrolysis stack 22. The protective electrolysis stack 22 includes multiple protective electrolysis cell groups. The protective electrolysis stack 22 has a protective positive electrode liquid inlet channel, a protective positive electrode liquid outlet channel, a protective negative electrode liquid inlet channel, and a protective negative electrode liquid outlet channel. The positive terminal of the protective electrolysis power supply 21 is connected to the anode current collector 228 of the protective electrolysis stack 22, and the negative terminal of the protective electrolysis power supply 21 is connected to the cathode current collector 227 of the protective electrolysis stack 22.

[0040] The electrolyte storage section includes a positive electrode electrolyte storage tank 3 and a negative electrode electrolyte storage tank 4. The positive electrode electrolyte storage tank 3 is used to store the positive electrode electrolyte, and the negative electrode electrolyte storage tank 4 is used to store the negative electrode electrolyte. For example, the negative electrode electrolyte is a vanadium electrolyte.

[0041] The positive electrode liquid storage tank 3 is connected in sequence to the outlet, the first pipeline 51, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the second pipeline 52, the protective positive electrode liquid inlet channel, the protective positive electrode liquid outlet channel, the third pipeline 53, and the inlet of the positive electrode liquid storage tank 3. The negative electrode liquid storage tank 4 is connected in sequence to the outlet, the fourth pipeline 54, the protective negative electrode liquid inlet channel, the protective negative electrode liquid outlet channel, the fifth pipeline 55, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the sixth pipeline 56, and the inlet of the negative electrode liquid storage tank 4. For example, the first pipeline 51 is equipped with a positive electrode liquid pump body 31, and the fourth pipeline 54 is equipped with a negative electrode liquid pump body 41.

[0042] According to the vanadium electrolyte electrolysis system of this embodiment, a relatively pure positive electrolyte first enters the main electrolysis section 1 for electrolysis and then enters the protective electrolysis section 2 for further electrolysis. The negative electrolyte containing impurities first enters the protective electrolysis section 2 for electrolysis and then enters the main electrolysis section 1 for electrolysis. This allows the protective electrolysis section 2 to absorb impurities in the negative electrolyte, resulting in less impurities in the negative electrolyte entering the main electrolysis section 1, thereby improving the service life of the main electrolysis section 1. The main electrolysis section 1 is the primary working electrolysis section, and the protective electrolysis section 2 is the electrolysis section that protects the main electrolysis section 1.

[0043] In some embodiments, the protective electrolytic cell assembly includes a cathode plate 222, an anode plate 223, and an ion exchange membrane 224. The cathode plate 222, ion exchange membrane 224, and anode plate 223 are arranged sequentially along a first direction. The cathode plate 222 and ion exchange membrane 224 define a cathode electrolyte chamber, and the anode plate 223 and ion exchange membrane 224 define an anode electrolyte chamber. A protective positive electrode liquid inlet channel and a protective positive electrode liquid outlet channel communicate with the anode electrolyte chamber, and a protective negative electrode liquid inlet channel and a protective negative electrode liquid outlet channel communicate with the cathode electrolyte chamber. Specifically, the positive electrode electrolyte can be introduced into the anode electrolyte chamber through the protective positive electrode liquid inlet channel for electrolysis to undergo an oxidation reaction, and then discharged from the protective positive electrode liquid outlet channel. The negative electrode electrolyte can be introduced into the cathode electrolyte chamber through the protective negative electrode liquid inlet channel for electrolysis to undergo a reduction reaction, and then discharged from the protective negative electrode liquid outlet channel.

[0044] like Figure 3 and Figure 4 As shown, in some embodiments, the protective electrolytic cell stack 22 further includes two end plates 221, a cathode insulating plate 226, a cathode current collector 227, an anode current collector 228, and an anode insulating plate 229. One of the two end plates 221, the cathode insulating plate 226, the cathode current collector 227, a plurality of protective electrolytic cell groups, the anode current collector 228, the anode insulating plate 229, and the other of the two end plates 221 are arranged sequentially in a first direction.

[0045] Each protective electrolyzer assembly also includes a flow frame 230, which is provided between the ion exchange membrane 224 and each of the anode plate 223 and cathode plate 222. Seals are provided between adjacent flow frames 230 and between adjacent ion exchange membranes 224 and anode plates 223 and cathode plates 222. These seals prevent electrolyte leakage and ensure interlayer sealing. The flow frame 230 serves as a frame for fixing the ion exchange membrane 224.

[0046] Specifically, end plates 221 are rigid plates at both ends of the battery stack, applying pressure to maintain the stack's seal. End plates 221 are made of aluminum alloy, titanium alloy, or stainless steel. Cathode insulating plate 226 and anode insulating plate 229 are located inside end plates 221 and are insulated from each other. Anode current collector 228 and cathode current collector 227 are both copper plates; anode current collector 228 is used to connect to the positive terminal of the power supply, and cathode current collector 227 is used to connect to the negative terminal of the power supply.

[0047] In some embodiments, the cathode electrolyte chamber is filled with cathode electrode material. Specifically, the thickness of the cathode electrode material is greater than or equal to 4 mm and less than or equal to 30 mm, and the compression ratio of the cathode electrode material is greater than or equal to 15% and less than or equal to 40%.

[0048] The cathode electrode material includes at least one of graphite felt, carbon paper, and carbon cloth to adsorb impurities in the negative electrode electrolyte. For example, the thickness of the cathode electrode material is 10 mm or 20 mm, and the compression ratio of the cathode electrode material is 40%. The cathode electrode material is graphite felt.

[0049] The anolyte chamber is filled with anolyte material. Specifically, the anolyte material includes at least one of a metal mesh and a metal felt to adsorb impurities in the positive electrolyte. For example, the anolyte material comprises one or more layers of metal mesh and metal felt arranged sequentially.

[0050] In some embodiments, the protective electrolytic cell stack 22 includes a bipolar plate 225, the anode side and cathode side of which respectively form an adjacent anode plate 223 and a cathode plate 222 in a first direction. Using the bipolar plate 225 as the anode plate 223 and cathode plate 222 reduces assembly difficulty. The bipolar plate 225 is made of a coated metal plate, a graphite plate, or a flexible graphite plate, thereby increasing its corrosion resistance. For example, the bipolar plate 225 is a flexible graphite plate.

[0051] like Figure 3 As shown, in some embodiments, the protective electrolysis unit 2 further includes a voltage monitor 23, which is connected to a plurality of tabs 24 on the protective electrolysis stack 22 to detect the voltage of the plurality of protective electrolytic cell groups in the protective electrolysis stack 22. Specifically, the plurality of tabs 24 on the protective electrolysis stack 22 are respectively connected to electrode plates (bipolar plate 225, anode plate 223, and cathode plate 222) to monitor the voltage of each protective electrolytic cell group.

[0052] In some embodiments, the main electrolysis unit further includes a main voltage monitor, which is connected to a plurality of tabs on the main electrolysis stack 22 to detect the voltage of a plurality of main electrolysis cells in the main electrolysis stack 2.

[0053] When the voltage of at least one of the multiple protective electrolytic cell groups in the protective electrolytic stack 22 is greater than or equal to 5V, the protective electrolytic stack 22 shall be cleaned and inspected. Specifically, an abnormally high conductivity indicates that there are many impurities in the protective electrolytic stack 22, requiring cleaning and inspection for normal use. For example, when the voltage of one of the protective electrolytic cell groups in the protective electrolytic stack 22 is greater than or equal to 5V, the protective electrolytic stack 22 shall be cleaned and inspected.

[0054] In some embodiments, both the third pipe 53 and the sixth pipe 56 include a light-transmitting observation section. When the solution inside the light-transmitting observation section of either the third pipe 53 or the sixth pipe 56 turns black, the protective electrolytic stack 22 is cleaned and inspected. Specifically, when there are many impurities in the protective electrolytic stack 22 that prevent it from absorbing impurities in the electrolyte, causing the electrolyte to turn black, the protective electrolytic stack 22 is cleaned and inspected in a timely manner to protect the main electrolysis unit 1.

[0055] like Figure 2 As shown, in some embodiments, there are two protective electrolysis units 2, which are arranged in parallel, with one in use and the other as a spare.

[0056] The second pipeline 52 is connected to the protective positive electrode liquid inlet channel of the two protective electrolysis sections 2 via two seventh pipelines 57, and each seventh pipeline 57 is equipped with a first on / off valve 61. The protective positive electrode liquid outlet channel of the two protective electrolysis sections 2 is connected to the third pipeline 53 via two eighth pipelines 58, and each eighth pipeline 58 is equipped with a second on / off valve 62.

[0057] The fourth pipe 54 is connected to the protective negative electrode liquid inlet channel of the two protective electrolysis sections 2 through two ninth pipes 59 respectively, and each ninth pipe 59 is equipped with a third on / off valve 63. The protective negative electrode liquid outlet channel of the two protective electrolysis sections 2 is connected to the fifth pipe 55 through two tenth pipes 60 respectively, and each tenth pipe 60 is equipped with a fourth on / off valve 64.

[0058] Specifically, when one of the two protective electrolytic units 2 is under maintenance, the other is started to reduce downtime. For example, the first on / off valve 61, the second on / off valve 62, the third on / off valve 63, and the fourth on / off valve 64 on the first of the two protective electrolytic units 2 can be opened, while the first on / off valve 61, the second on / off valve 62, the third on / off valve 63, and the fourth on / off valve 64 on the second protective electrolytic unit 2 are closed. When maintenance is required on the first protective electrolytic unit 2, the first on / off valve 61, the second on / off valve 62, the third on / off valve 63, and the fourth on / off valve 64 on the first protective electrolytic unit 2 are closed, while the first on / off valve 61, the second on / off valve 62, the third on / off valve 63, and the fourth on / off valve 64 on the second protective electrolytic unit 2 are opened.

[0059] In one specific embodiment, a vanadium electrolyte electrolysis system according to an embodiment of the present invention is used to reduce tetravalent vanadium oxysulfate solution to 3.5-valent vanadium electrolyte, and the main electrolytic cell group has an electrolysis capacity of 1 m³ / s. 3 / d, with an effective area of ​​50cm*50cm, the main electrolytic cell stack 12 includes 5 main electrolytic cell groups. The protective electrolytic cell stack 22 consists of 10 protective electrolytic cell groups with an effective area of ​​20cm*20cm connected in series.

[0060] In the protective electrolytic cell stack 22, the cathode electrode material is 4.5mm carbon felt, the bipolar plate 225 is a flexible graphite plate, and the anode electrode material is a titanium mesh with a total thickness of 1.8mm and a titanium fiber felt of 0.4mm. The positive electrode electrolyte is 4mol / L sulfuric acid, the negative electrode electrolyte is 1.7mol / L vanadium oxysulfate, the electrolysis current is 20A, and the total voltage of the protective electrolytic cell group is 22V at the start of electrolysis.

[0061] The electrolysis current of the main electrolytic cell group is set to 250A (100mA / cm). 2 At the start of electrolysis, the total voltage of the main electrolytic cell group was 14.2V. Batch electrolysis was used, with each electrolysis cycle lasting 1 minute. 3 Electrolysis is stopped after the electrolyte is electrolyzed from +4 valence to 3.5 valence, and the cathode electrolyte is replaced with a new one; water is added to keep the volume of the anode electrolyte constant.

[0062] When the voltage of any one group in the protective electrolytic cell group of the protective electrolytic cell stack 22 rises above 5V, a new protective device shall be replaced. The failure criterion for the main electrolytic cell group is that the voltage of one group in the main electrolytic cell group rises to 5V. The service life of the main electrolytic cell group exceeds 5000 hours, and the current efficiency is maintained at 88%-95% during electrolysis.

[0063] Comparative Example 1: The conditions are the same as in the embodiment, but without a protection device. The failure criterion for the main electrolytic cell group is defined as the voltage of one of the main electrolytic cells rising to 5V. The lifespan of the main electrolytic cell group is only 2700 hours. During electrolysis, the current efficiency continuously decreases, and the current efficiency monitored in the last few hours is only 70%-77%.

[0064] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0066] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0067] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0068] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A vanadium electrolyte electrolysis system, characterized in that, include: The main electrolysis unit includes a main electrolysis power supply and a main electrolysis stack. The main electrolysis stack includes multiple main electrolysis cell groups. The main electrolysis stack has a main positive electrode liquid inlet channel, a main positive electrode liquid outlet channel, a main negative electrode liquid inlet channel, and a main negative electrode liquid outlet channel. The positive terminal of the main electrolysis power supply is connected to the anode current collector of the main electrolysis stack, and the negative terminal of the main electrolysis power supply is connected to the cathode current collector of the main electrolysis stack. A protective electrolysis unit is provided, comprising a protective electrolysis power supply and a protective electrolysis stack. The protective electrolysis stack includes multiple protective electrolysis cell groups. The protective electrolysis stack has a protective positive electrode liquid inlet channel, a protective positive electrode liquid outlet channel, a protective negative electrode liquid inlet channel, and a protective negative electrode liquid outlet channel. The positive terminal of the protective electrolysis power supply is connected to the anode current collector of the protective electrolysis stack, and the negative terminal of the protective electrolysis power supply is connected to the cathode current collector of the protective electrolysis stack. The liquid storage section includes a positive electrode liquid storage tank and a negative electrode liquid storage tank. The positive electrode liquid storage tank is used to store the positive electrode electrolyte, and the negative electrode liquid storage tank is used to store the negative electrode electrolyte. The outlet of the positive electrode liquid storage tank, the first pipeline, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the second pipeline, the protective positive electrode liquid inlet channel, the protective positive electrode liquid outlet channel, the third pipeline, and the inlet of the positive electrode liquid storage tank are connected in sequence. The outlet of the negative electrode liquid storage tank, the fourth pipeline, the protective negative electrode liquid inlet channel, the protective negative electrode liquid outlet channel, the fifth pipeline, the main positive electrode liquid inlet channel, the main positive electrode liquid outlet channel, the sixth pipeline, and the inlet of the negative electrode liquid storage tank are connected in sequence.

2. The vanadium electrolyte electrolysis system according to claim 1, characterized in that, The protective electrolytic cell assembly includes a cathode plate, an anode plate, and an ion exchange membrane. The cathode plate, the ion exchange membrane, and the anode plate are arranged sequentially along a first direction. The cathode plate and the ion exchange membrane define a cathode electrolyte chamber, and the anode plate and the ion exchange membrane define an anode electrolyte chamber. The protective positive electrode liquid inlet channel and the protective positive electrode liquid outlet channel are connected to the anode electrolyte chamber, and the protective negative electrode liquid inlet channel and the protective negative electrode liquid outlet channel are connected to the cathode electrolyte chamber.

3. The vanadium electrolyte electrolysis system according to claim 2, characterized in that, The protective electrolytic cell stack also includes two end plates, a cathode insulating plate, a cathode current collector, an anode current collector, and an anode insulating plate. One of the two end plates, the cathode insulating plate, the cathode current collector, the plurality of protective electrolytic cell groups, the anode current collector, the anode insulating plate, and the other of the two end plates are arranged sequentially in the first direction. Each of the protective electrolytic cells also includes a liquid flow frame, which is provided between the ion exchange membrane and each of the anode plate and the cathode plate.

4. The vanadium electrolyte electrolysis system according to claim 2, characterized in that, The cathode electrolyte chamber is filled with cathode electrode material, and the anolyte chamber is filled with anolyte material.

5. The vanadium electrolyte electrolysis system according to claim 4, characterized in that, The thickness of the cathode electrode material is greater than or equal to 4 mm and less than or equal to 30 mm, and the compression ratio of the cathode electrode material is greater than or equal to 15% and less than or equal to 40%.

6. The vanadium electrolyte electrolysis system according to claim 4, characterized in that, The cathode electrode material includes at least one of graphite felt, carbon paper, and carbon cloth; The anode electrode material includes at least one of a metal mesh and a metal felt.

7. The vanadium electrolyte electrolysis system according to claim 2, characterized in that, The protective electrolytic stack includes bipolar plates, wherein the anode side and the cathode side of the bipolar plates are respectively arranged adjacent to the anode plate and the cathode plate in the first direction, and the bipolar plates are made of coated metal plates, graphite plates or flexible graphite plates.

8. The vanadium electrolyte electrolysis system according to claim 1, characterized in that, The protective electrolysis unit also includes a voltage monitor, which is connected to multiple tabs on the protective electrolysis stack to detect the voltage of the multiple protective electrolysis cell groups of the protective electrolysis stack. When the voltage of at least one of the multiple protective electrolysis cell groups of the protective electrolysis stack is greater than or equal to 5V, the protective electrolysis stack is cleaned and repaired.

9. The vanadium electrolyte electrolysis system according to claim 1, characterized in that, Both the third and sixth pipelines include a light-transmitting observation section. When the solution inside the light-transmitting observation section of either the third or sixth pipeline turns black, the protective electrolytic cell stack is cleaned and repaired.

10. The vanadium electrolyte electrolysis system according to claim 1, characterized in that, There are two protective electrolysis units; The second pipeline is connected to the protective positive electrode liquid inlet channel of the two protective electrolysis sections through two seventh pipelines respectively, and each of the seventh pipelines is provided with a first opening and closing valve; The protective positive electrode liquid discharge channels of the two protective electrolysis sections are respectively connected to the third pipeline through two eighth pipelines, and each of the eighth pipelines is provided with a second opening and closing valve; The fourth pipeline is connected to the protective negative electrode liquid inlet channel of the two protective electrolysis sections through two ninth pipelines respectively, and each of the ninth pipelines is provided with a third opening and closing valve; The protective negative electrode liquid discharge channels of the two protective electrolysis sections are connected to the fifth pipeline through two tenth pipelines respectively, and each of the tenth pipelines is provided with a fourth on / off valve.

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