All-vanadium redox flow battery device for recycling negative electrode hydrogen for positive electrode liquid storage tank

Abstract

The utility model discloses an all-vanadium redox flow battery device for recycling negative electrode hydrogen for a positive electrode liquid storage tank, which comprises the positive electrode liquid storage tank, the positive electrode liquid storage tank is connected with a negative electrode liquid storage tank through a fourth pipeline, the negative electrode liquid storage tank is connected with a gas storage tank through a first pipeline, and the gas storage tank is connected with an impurity removal device through a second pipeline. And the impurity removal device is connected with the positive electrode liquid storage tank through a third pipeline. According to the device disclosed by the utility model, hydrogen separated out by negative electrode side reaction can be purified and recycled into the positive electrode liquid storage tank for reduction, so that the utilization rate of the hydrogen is greatly improved, meanwhile, the problem of valence imbalance of electrolyte is avoided, and the battery capacity is recovered.

Description

Technical Field

[0001] The utility model belongs to the technical field of all-vanadium liquid flow battery devices, and in particular relates to an all-vanadium liquid flow battery device which recovers negative electrode hydrogen gas for use in a positive electrode liquid storage tank. Background Art

[0002] All-vanadium liquid flow batteries have the characteristics of safe and stable operation, long cycle life, and environmental friendliness. They have unique advantages in the field of energy storage and have quickly become a hot topic in the energy storage industry in recent years.

[0003] As the core energy storage medium of the all-vanadium liquid flow battery, the electrolyte solution gradually loses its average valence after a long period of charge and discharge, and the battery will also experience capacity decay. There are many reasons for the decay, among which the more important reason is the negative electrode hydrogen evolution caused by the side reaction. As the cycle progresses, the negative electrode continues to precipitate hydrogen. The specific reaction is as follows:

[0004] V 2+ +2H + =V 3+ +H 2 ;

[0005] After long-term operation, the all-vanadium liquid flow battery will have a height difference between the positive and negative electrode liquid levels due to water migration or vanadium ion penetration, and the positive electrode liquid level is usually higher than the negative electrode liquid level; the solubility of pentavalent vanadium ions in the positive electrode electrolyte is relatively low, and the high-temperature stability is relatively poor, which is easy to form precipitation. This precipitation is irreversible, resulting in a waste of vanadium ions; trace side reactions occur on the positive and negative electrodes, and the long-term accumulation of trace vanadium ions through the ion exchange membrane. This series of problems leads to an imbalance in the valence state of the electrolyte, thereby causing the system's energy storage capacity to decay.

[0006] In order to restore the capacity of the all-vanadium flow battery, the vanadium electrolyte needs to be treated regularly. The measures that can be taken include: mixing the positive and negative electrolytes; adding oxalic acid, glucose and other substances to the positive electrode solution to reduce the pentavalent vanadium to the required average valence state. The former requires the regular addition of reducing agents, which consumes a lot of manpower and material resources and cannot fundamentally solve the problem. The latter will inevitably introduce impurity residues, which also has a certain impact on the performance and safety of the all-vanadium flow battery.

[0007] After searching, the existing patent (publication number: CN 220753494 U) discloses a negative electrode electrolyte tank device of an all-vanadium liquid flow battery with hydrogen recovery, comprising a tank body, a mounting plate fixedly connected to one side of the tank body, a storage box fixedly connected to the top of the mounting plate, a hydrogen storage material arranged inside the storage box, a gas transmission pipe arranged between the storage box and the tank body, and a control valve arranged on the surface of the gas transmission pipe. The beneficial effect is that the negative electrode electrolyte tank of the all-vanadium liquid flow battery with a hydrogen recovery device can conveniently control the air transportation between the tank body and the storage box by setting a control valve, facilitate the storage of hydrogen, and facilitate the replacement of hydrogen storage materials. By storing hydrogen, the processing working environment can be guaranteed, and the hydrogen can be utilized. By setting a support component, the structure can be supported to ensure the stability of the structure.

[0008] It realizes the recovery of hydrogen released by the negative electrode side reaction in the storage tank, effectively reducing the flammability and explosion risk of hydrogen in the environment. However, it has its shortcomings, that is, how to purify the stored hydrogen before using it for positive electrode reduction. Utility Model Content

[0009] The utility model aims to provide an all-vanadium liquid flow battery device which recycles negative electrode hydrogen for use in a positive electrode liquid storage tank, thereby solving the problem that the hydrogen generated by the negative electrode side reaction cannot be purified and then used for positive electrode reduction.

[0010] The technical solution adopted by the utility model is to recycle negative electrode hydrogen for use in an all-vanadium liquid flow battery device for a positive electrode storage tank, comprising a positive electrode storage tank, the positive electrode storage tank being connected to the negative electrode storage tank via a fourth pipeline, the negative electrode storage tank being connected to a gas storage tank via a first pipeline, the gas storage tank being connected to a deoxidation unit via a second pipeline, and the deoxidation unit being connected to the positive electrode storage tank via a third pipeline.

[0011] The utility model is also characterized in that:

[0012] The fourth pipeline is provided with a power pump.

[0013] The first pipeline is provided with a first gas regulating valve and a first gas impurity removal device, and the first gas regulating valve is arranged close to the negative electrode liquid storage tank.

[0014] A hydrogen concentration sensor, a second gas regulating valve, and a second gas impurity removal device are arranged on the second pipeline. The hydrogen concentration sensor is arranged close to the gas storage tank, the second gas impurity removal device is arranged close to the deoxygenation unit, and the second gas regulating valve is arranged between the hydrogen concentration sensor and the second gas impurity removal device.

[0015] The third pipeline is provided with a third gas regulating valve and a gas flow meter, and the third gas regulating valve is arranged close to the deoxygenation unit.

[0016] The deoxidation unit comprises a deoxidation tank body, in which a deoxidizer and a desiccant are filled.

[0017] The beneficial effects of the utility model are:

[0018] (1) The utility model recycles hydrogen gas from the negative electrode into an all-vanadium liquid flow battery device for use in a positive electrode liquid storage tank. By setting a first gas regulating valve, a first gas impurity removal device, and a second gas regulating valve, and a second gas impurity removal device, hydrogen gas can be freely controlled by the first gas regulating valve and the second gas regulating valve according to the side reaction hydrogen evolution generated in the negative electrode liquid storage tank, and SO generated by concentrated sulfuric acid in the negative electrode liquid storage tank is 2 The gases can also be absorbed by the first gas impurity removal device and the second gas impurity removal device, leaving only hydrogen to be stored in the gas storage tank. The treated hydrogen has high purity, avoiding the introduction of impurities into the positive electrode storage tank;

[0019] (2) The utility model recycles the negative electrode hydrogen for use in the positive electrode liquid storage tank of the all-vanadium liquid flow battery device, and is provided with a deoxygenation unit to deoxygenate and purify the hydrogen released by the negative electrode side reaction, and is also provided with a third gas regulating valve at the positive electrode liquid inlet, which can freely control the amount of use, and is provided with a gas flow meter to detect the amount of hydrogen flowing through the pipeline, so as to facilitate monitoring at any time;

[0020] (3) The utility model uses an all-vanadium liquid flow battery device that recycles hydrogen from the negative electrode for use in a positive electrode liquid storage tank. The device can purify the hydrogen released by the negative electrode side reaction and monitor the concentration and flow of the hydrogen recovered to the positive electrode liquid storage tank online and perform reduction, thereby greatly improving the utilization rate of the hydrogen. At the same time, it avoids the imbalance of the electrolyte valence state and restores the battery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The utility model is a schematic structural diagram of an all-vanadium liquid flow battery device that recovers negative electrode hydrogen for use in a positive electrode liquid storage tank.

[0022] In the figure, 1. positive electrode liquid storage tank, 2. negative electrode liquid storage tank, 3. power pump, 4. first gas regulating valve, 5. first gas impurity removal device, 6. gas storage tank, 7. hydrogen concentration sensor, 8. second gas regulating valve, 9. second gas impurity removal device, 10. deoxygenation unit, 11. third gas regulating valve, 12. gas flow meter, 13. first pipeline, 14. second pipeline, 15. third pipeline, 16. fourth pipeline. DETAILED DESCRIPTION

[0023] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0024] Example 1

[0025] The utility model recycles hydrogen gas from the negative electrode into an all-vanadium liquid flow battery device for use in a positive electrode liquid storage tank. Figure 1 As shown, it includes a positive electrode storage tank 1 for storing positive electrode electrolyte, the positive electrode storage tank 1 is connected to the negative electrode storage tank 2 through a fourth pipeline 16, the negative electrode storage tank 2 is used to store negative electrode electrolyte, and a power pump 3 is provided on the fourth pipeline 16. The power pump 3 is used to drive the positive electrode storage tank 1 and the negative electrode storage tank 2 to realize the circulation operation of the entire system under the drive of the pump. The negative electrode storage tank 2 is connected to the gas storage tank 6 through the first pipeline 13. The gas storage tank 6 is used to store hydrogen generated by the side reaction of the negative electrode storage tank. The gas storage tank 6 is connected to the negative electrode storage tank 2 through the second pipeline 14. The pipeline 14 is connected to the deoxygenation unit 10, which is used to deoxygenate the gas produced by the side reaction of the negative electrode liquid storage tank to improve the purity of the gas and allow hydrogen to enter the positive electrode liquid storage tank 1. The deoxygenation unit 10 is connected to the positive electrode liquid storage tank 1 through a third pipeline 15. The third pipeline 15 is provided with a third gas regulating valve 11 and a gas flow meter 12. The third gas regulating valve 11 is used to freely control the flow of the gas, and the gas flow meter 12 is used to monitor the flow of the gas. The third gas regulating valve 11 is arranged close to the deoxygenation unit 10.

[0026] Example 2

[0027] On the basis of Example 1, a first gas regulating valve 4 and a first gas impurity removal device 5 are provided on the first pipeline 13. The first gas regulating valve 4 is used to freely control the flow rate of the gas. The first gas impurity removal device 5 is used to remove sulfur dioxide from the gas generated by the side reaction of the negative electrode liquid storage tank. The first gas regulating valve 4 is arranged close to the negative electrode liquid storage tank 2.

[0028] The second pipeline 14 is provided with a hydrogen concentration sensor 7, a second gas regulating valve 8, and a second gas impurity removal device 9. The second gas regulating valve 8 is used for freely controlling the flow rate of the gas. The second gas impurity removal device 9 is used for secondary removal of sulfur dioxide in the gas produced by the side reaction of the negative electrode liquid storage tank. The hydrogen concentration sensor 7 is used for measuring the hydrogen concentration coming out of the gas storage tank 6 and the hydrogen concentration in the second pipeline 14. When the hydrogen concentration reaches the target value, the second gas regulating valve 8 is opened to further transport the hydrogen. The hydrogen concentration sensor 7 is arranged close to the gas storage tank 6, the second gas impurity removal device 9 is arranged close to the deoxygenation unit 10, and the second gas regulating valve 8 is arranged between the hydrogen concentration sensor 7 and the second gas impurity removal device 9.

[0029] Example 3

[0030] Based on Example 2, the deoxygenation unit 10 includes a deoxygenation tank body, which is filled with a deoxidizer and a desiccant for removing and drying oxygen in the gas produced by the side reaction of the negative electrode liquid storage tank to improve the purity of the gas and prevent impurities and moisture from entering the positive electrode liquid storage tank 1.

[0031] The working principle of the all-vanadium liquid flow battery device for recycling negative electrode hydrogen for positive electrode storage tank of the utility model is as follows: the gas generated by the side reaction of the battery stack in the negative electrode storage tank 2 enters the first pipeline 13 and passes through the first gas impurity removal device 5 for sequential impurity removal treatment, wherein the first hydrogen impurity removal device 5 is equipped with sodium hydroxide solution to remove sulfur dioxide, and then enters the gas storage tank 6 for storage, and the hydrogen concentration is monitored by the hydrogen concentration sensor 7. When the hydrogen concentration reaches the target value, the second gas regulating valve 8 is opened, and the hydrogen enters the second gas impurity removal device 9 through the second pipeline 14 for secondary impurity removal treatment, wherein the second gas impurity removal device 9 is equipped with sodium hydroxide solution to remove sulfur dioxide for a secondary time, and then enters the deoxygenation unit 10 for deoxygenation and drying treatment, and then the flow rate is adjusted by the third gas regulating valve 11, and finally enters the positive electrode storage tank 1 for reduction.

Claims

1. A vanadium liquid flow battery device that recycles negative electrode hydrogen gas for use in a positive electrode liquid storage tank, characterized in that: The invention comprises a positive electrode liquid storage tank (1), wherein the positive electrode liquid storage tank (1) is connected to a negative electrode liquid storage tank (2) via a fourth pipeline (16), the negative electrode liquid storage tank (2) is connected to a gas storage tank (6) via a first pipeline (13), the gas storage tank (6) is connected to a deoxidation unit (10) via a second pipeline (14), and the deoxidation unit (10) is connected to the positive electrode liquid storage tank (1) via a third pipeline (15).

2. The all-vanadium liquid flow battery device for recovering negative electrode hydrogen for use in a positive electrode liquid storage tank according to claim 1, characterized in that: The fourth pipeline (16) is provided with a power pump (3).

3. The all-vanadium liquid flow battery device for recovering negative electrode hydrogen for use in a positive electrode liquid storage tank according to claim 1, characterized in that: The first pipeline (13) is provided with a first gas regulating valve (4) and a first gas impurity removal device (5); the first gas regulating valve (4) is arranged close to the negative electrode liquid storage tank (2).

4. The all-vanadium liquid flow battery device for recovering negative electrode hydrogen for use in a positive electrode liquid storage tank according to claim 1, characterized in that: The second pipeline (14) is provided with a hydrogen concentration sensor (7), a second gas regulating valve (8), and a second gas impurity removal device (9); the hydrogen concentration sensor (7) is provided close to the gas storage tank (6); the second gas impurity removal device (9) is provided close to the deoxygenation unit (10); and the second gas regulating valve (8) is provided between the hydrogen concentration sensor (7) and the second gas impurity removal device (9).

5. The all-vanadium liquid flow battery device for recovering negative electrode hydrogen for use in a positive electrode liquid storage tank according to claim 1, characterized in that: The third pipeline (15) is provided with a third gas regulating valve (11) and a gas flow meter (12), and the third gas regulating valve (11) is arranged close to the deoxygenation unit (10).

6. The all-vanadium liquid flow battery device for recovering negative electrode hydrogen for use in a positive electrode liquid storage tank according to claim 1, characterized in that: The deoxidation unit (10) comprises a deoxidation tank body, in which a deoxidizer and a desiccant are filled.

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