A negative liquid storage tank of all-vanadium redox flow battery

Abstract

The utility model discloses a kind of full vanadium liquid flow battery negative pole liquid storage tank, it is related to full vanadium liquid flow battery field, including tank body, the top of tank body is provided with tank cover, tank body and tank cover are connected by sealing structure, form closed space, the tank cover is equipped with for filling inert gas inlet valve, for discharging hydrogen gas outlet pipe and for adding electrolyte liquid filling valve, the utility model is filled with inert gas by sealing design to tank body and tank cover, and the space that is not filled with electrolyte is filled, completely isolate outside air, avoid V (II) Ion is oxidized, to ensure the stability of electrolyte and battery capacity, by setting hydrogen gas collecting device at the top of gas outlet pipe, when hydrogen gas accumulation in tank body leads to air pressure rise, can be monitored by pressure detection component and open gas outlet valve to discharge hydrogen, avoid excessive pressure in tank, improve safety, and the hydrogen gas collected can be further purified and used for other industrial or energy application, realize resource recovery.

Description

Technical Field

[0001] This utility model belongs to the field of vanadium redox flow batteries, specifically relating to a negative electrode storage tank for vanadium redox flow batteries. Background Technology

[0002] The vanadium redox flow battery (VRFB) is a novel type of energy storage battery. Its positive and negative electrode electrolytes are composed of strong acid solutions of vanadium ions in different valence states (V(Ⅳ) / V(Ⅴ) and V(Ⅱ) / V(Ⅲ)), respectively. During charging, V(Ⅲ) ions in the negative electrode electrolyte are reduced to V(Ⅱ) ions, while the reverse reaction occurs during discharging.

[0003] Vanadium redox flow batteries store and release electrical energy by gaining and losing electrons in vanadium ions. Among them, V(II) ions are easily oxidized by the outside air into V(III) ions. In this way, the electrical energy stored by the oxidized V(II) ions is directly converted into chemical energy, resulting in a decrease in the capacity of the battery electrolyte and an increase in the valence state.

[0004] To address the issue that V(II) ions in the negative electrode electrolyte of vanadium redox flow batteries are easily oxidized to V(III) ions upon contact with outside air, resulting in a decrease in electrolyte capacity and an increase in overall valence state, the current common method is to use a sealed negative electrode storage tank to isolate the negative electrode electrolyte from outside air, thereby protecting the V(II) ions in the negative electrode electrolyte from oxidation. However, this type of storage tank has the following drawbacks:

[0005] Air residue problem: When the electrolyte tank is not completely filled with electrolyte, the residual air will still oxidize V(II) ions, affecting the battery capacity.

[0006] Hydrogen accumulation risk: During battery operation, hydrogen evolution side reaction may occur, and hydrogen will continuously accumulate in the sealed liquid storage tank, causing the pressure inside the tank to rise, which poses a safety hazard.

[0007] Waste of inert gas: When existing liquid storage tanks discharge hydrogen, they may also discharge inert gas, resulting in a waste of resources.

[0008] Therefore, we propose a negative electrode storage tank for vanadium redox flow batteries to solve the above problems. Utility Model Content

[0009] To address the problems of traditional electrolyte storage tanks, where residual air can still oxidize V(II) ions when the tank is not fully filled with electrolyte, affecting battery capacity, and the hydrogen evolution side reaction that occurs during battery operation, causing hydrogen to accumulate in the sealed storage tank and leading to increased pressure and safety hazards, this utility model provides a negative electrode storage tank for a vanadium redox flow battery.

[0010] The solution adopted by this utility model to solve its technical problem is: a negative electrode storage tank for a vanadium redox flow battery, including a tank body, a tank cover on the top of the tank body, the tank body and the tank cover are connected by a sealing structure to form a sealed space, and the tank cover is provided with an inlet valve for filling in inert gas, an outlet pipe for discharging hydrogen gas and a liquid filling valve for adding electrolyte.

[0011] The outlet pipe is equipped with an outlet valve and a pressure detection component from top to bottom, and its top end is connected to the port of the hydrogen collection device.

[0012] The tank body has a liquid outlet pipe and a liquid outlet valve installed on the lower side of the tank body. The tank body has a liquid return pipe on the upper side of the tank body. The outer end of the liquid return pipe is equipped with a liquid return valve, and its inner end extends to the other side of the inner cavity of the tank body.

[0013] The tank is equipped with a liquid exchange pipe and a liquid exchange valve at the bottom.

[0014] Preferably, the sealing structure is a flange structure or a threaded structure.

[0015] Preferably, both the tank body and the tank lid are made of acid-resistant polymer materials.

[0016] Preferably, the bottom of the tank is designed in a funnel shape, and the upper part is designed in an inverted funnel shape.

[0017] Preferably, the port of the hydrogen collection device is equipped with a filter containing calcium oxide solid for filtering water vapor and acidic substances from the hydrogen.

[0018] Preferably, the inert gas is an inert gas other than helium.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] 1. This utility model adopts a sealed design for the tank body and lid, and fills the space not filled with electrolyte with inert gas to completely isolate it from the outside air, preventing V(II) ions from being oxidized, thereby ensuring the stability of the electrolyte and the battery capacity. By setting a hydrogen collection device at the top of the gas outlet pipe, when hydrogen accumulates in the tank and causes the gas pressure to rise, the pressure detection component can monitor and open the gas outlet valve to discharge the hydrogen, avoiding excessive pressure in the tank and improving safety. Furthermore, the collected hydrogen can be further purified and used for other industrial or energy applications, realizing resource recovery and improving economic efficiency.

[0021] 2. The upper part of the tank of this utility model adopts an inverted funnel-shaped design, which concentrates hydrogen at the top, making it easy to collect efficiently. At the same time, it reduces the discharge of inert gas with hydrogen and reduces gas loss. The bottom of the tank adopts a funnel-shaped design to ensure that it can be completely emptied when the electrolyte is replaced, avoiding the impact of old electrolyte residue on battery performance. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the front cross-sectional structure of the present invention. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the front cross-sectional structure of the present invention. Figure 2 ;

[0024] Figure 3 This is a schematic diagram of the front cross-sectional structure of the present invention. Figure 3 ;

[0025] Figure 4 This is a schematic diagram of the front cross-sectional structure of the present invention. Figure 4 ;

[0026] Figure 5 This is a schematic diagram of the front cross-sectional structure of the present invention. Figure 5 .

[0027] In the diagram: 1. Tank body, 2. Tank cover, 3. Inlet valve, 4. Pressure detection component, 5. Outlet valve, 6. Calcium oxide filter, 7. Hydrogen collection device, 8. Liquid filling valve, 9. Liquid return valve, 10. Liquid outlet valve, 11. Liquid replacement valve, 12. Outlet pipe, 13. Liquid return pipe. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Please see Figure 1-5 This utility model provides a technical solution for a negative electrode storage tank for an all-vanadium redox flow battery:

[0030] Example 1:

[0031] according to Figure 1-5 As shown, the device includes a tank 1. The bottom of the tank 1 has a funnel-shaped design, and the top has an inverted funnel-shaped design. The inverted funnel-shaped design at the top of the tank 1 concentrates hydrogen gas at the top for efficient collection and reduces the discharge of inert gases with the hydrogen, thus reducing gas loss. The funnel-shaped design at the bottom of the tank 1 ensures complete emptying when the electrolyte is replaced, preventing residual old electrolyte from affecting battery performance. The top of the tank 1 is equipped with a lid 2. Both the tank 1 and the lid 2 are made of acid-resistant polymer materials, extending their service life. The tank 1 adopts an integrated design to ensure the airtightness and strength of the storage tank. The tank 1 and the lid 2 are connected by a sealing structure to form a sealed space. The sealing structure can be a flange structure or a threaded structure.

[0032] The can lid 2 is equipped with an inlet valve 3 for filling in inert gas, an outlet pipe 12 for discharging hydrogen gas, and a liquid filling valve 8 for adding electrolyte. The inert gas is an inert gas other than helium.

[0033] The outlet pipe 12 is equipped with an outlet valve 5 and a pressure detection component 4 from top to bottom. Its top end is connected to the port of the hydrogen collection device 7. The outlet valve 5 can be a manual valve or a solenoid valve. The pressure detection component 4 can be a pressure gauge or a pressure sensor. When hydrogen accumulates in the tank 1 and the gas pressure rises, the outlet valve 5 can be opened by the pressure detection component 4 to release the hydrogen, so as to avoid excessive pressure in the tank, improve safety, and the collected hydrogen can be further purified and used for other industrial or energy applications, realizing resource recovery and improving economic benefits.

[0034] The lower side of the tank body 1 is provided with an outlet pipe and an outlet valve 10. The upper side of the tank body 1 is provided with a return pipe 13. The outer end of the return pipe 13 is equipped with a return valve 9, and its inner end extends to the other side of the inner cavity of the tank body 1, so that the returned electrolyte is fully mixed with the electrolyte in the tank body 1, thereby improving the battery operating efficiency.

[0035] The bottom of the tank 1 is equipped with a liquid exchange pipe and a liquid exchange valve 11. By opening the liquid exchange valve 11, the electrolyte in the tank 1 is discharged.

[0036] In practical use, this utility model provides a negative electrode storage tank for a vanadium redox flow battery.

[0037] S1, such as Figure 1 As shown: Fill tank 1 with 3.5 valence electrolyte (3.5 valence electrolyte refers to electrolyte with the same concentration of V(III) ions and V(IV) ions), seal tank cover 2 to the top opening of tank 1, close all valves, and seal the entire storage tank;

[0038] S2, such as Figure 2 As shown: After the air inlet valve 3 is connected to the air filling pipeline, open the air inlet valve 3 and at the same time open the liquid replacement valve 11. While the 3.5 valence electrolyte flows out, inert gas is introduced. In this way, no outside air is introduced into the tank 1, so as to prevent the negative electrode electrolyte from being oxidized by the outside air. The amount of 3.5 valence electrolyte to be retained in the tank 1 is determined according to the actual needs. Then close the liquid replacement valve 11 and the air inlet valve 3.

[0039] S3, such as Figure 3 As shown: When the return valve 9 and the outlet valve 10 are opened, the vanadium redox flow battery begins to charge and discharge. After one charge and discharge cycle, the 3.5 valence electrolyte in tank 1 is converted into a negative electrode electrolyte containing V(II) ions and V(III) ions. At the same time, a hydrogen evolution side reaction is also occurring in tank 1. The hydrogen gas produced by the side reaction has the lowest density, so it is concentrated at the top of tank 1. As the charge and discharge continue, the hydrogen gas continues to accumulate, and the pressure gauge reading continues to increase.

[0040] S4, such as Figure 4 As shown: When the pressure gauge reaches a certain value, open the outlet valve 5, and hydrogen can enter the hydrogen collection device 7. When the pressure gauge reading returns to normal pressure or is slightly higher than normal pressure, close the outlet valve 5 and continue charging and discharging.

[0041] S5, such as Figure 5 As shown: When it is necessary to add electrolyte to the storage tank, connect the liquid addition valve 8 to the electrolyte container, disconnect the hydrogen collection device 7, and open the liquid addition valve 8 and the gas outlet valve 5 at the same time. After the liquid addition is completed, close all valves.

[0042] Example 2:

[0043] Based on Example 1, such as Figure 1 As shown, the port of the hydrogen collection device 7 is equipped with a filter 6 containing calcium oxide solid, which is used to filter out water vapor and acidic substances that may be present in the hydrogen.

Claims

1. A negative electrode storage tank for a vanadium redox flow battery, comprising a tank body, a tank cover on the top of the tank body, the tank body and the tank cover being connected by a sealing structure to form a sealed space, characterized in that: The can lid is equipped with an inlet valve for filling inert gas, an outlet pipe for discharging hydrogen gas, and a liquid filling valve for adding electrolyte. The outlet pipe is equipped with an outlet valve and a pressure detection component from top to bottom, and its top end is connected to the port of the hydrogen collection device. The tank body has a liquid outlet pipe and a liquid outlet valve installed on the lower side of the tank body. The tank body has a liquid return pipe on the upper side of the tank body. The outer end of the liquid return pipe is equipped with a liquid return valve, and its inner end extends to the other side of the inner cavity of the tank body. The tank is equipped with a liquid exchange pipe and a liquid exchange valve at the bottom.

2. The negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: The sealing structure is either a flange structure or a threaded structure.

3. The negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: Both the tank body and the tank lid are made of acid-resistant polymer materials.

4. The negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: The bottom of the tank is designed in a funnel shape, and the upper part is designed in an inverted funnel shape.

5. The negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: The hydrogen collection device is equipped with a filter containing calcium oxide solid at its port for filtering water vapor and acidic substances from the hydrogen.

6. The negative electrode storage tank of the all-vanadium redox flow battery according to claim 1, characterized in that: The inert gas is an inert gas other than helium.

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