Overflow communication device applied to zinc-bromine flow battery

Abstract

The novel overflow communicating device comprises an overflow communicating pipe and a bromine-resistant layer, one end of the overflow communicating pipe is connected with a zinc-side liquid storage tank, the other end of the overflow communicating pipe is connected with a bromine-side liquid storage tank, and the bromine-resistant layer is arranged on one side, close to the bromine-side liquid storage tank, of the overflow communicating pipe; the bromine-resistant layer comprises a first loose joint, a sealing gasket, a bromine-resistant film and a second loose joint; the sealing gaskets are respectively arranged between the bromine blocking film and the first loose joint and between the bromine blocking film and the second loose joint; when migration occurs and the liquid level of the bromine-side electrolyte is higher than the overflow port, the bromine-side electrolyte flows back to the zinc-side liquid storage tank through the overflow communication device, and the bromine blocking layer can block complexing bromine to allow water and other ions to pass through, so that the electrolytes on the two sides can be relatively balanced, and self-discharge of the zinc-bromine flow battery can be avoided.

Description

Technical Field

[0001] The utility model relates to an overflow connecting device applied to a zinc-bromine liquid flow battery, belonging to the field of battery equipment. Background Art

[0002] In the existing zinc-bromine flow battery, due to the concentration difference and pressure difference of the liquid flow on both sides of the diaphragm during the charge and discharge process, the electrolyte of the zinc-bromine flow battery will migrate to one side. Therefore, in order to prevent too much electrolyte on one side and too little electrolyte on the other side, a connecting device is usually designed between the zinc side storage tank and the bromine side storage tank, such as Figure 1 As shown, when the zinc-bromine flow battery has electrolyte migration, the liquid level reaches the position of the connecting device and overflows to the other side through the connecting device, thereby ensuring that the volume of the zinc-side electrolyte and the bromine-side electrolyte will not differ too much. However, this overflow connecting device has some shortcomings. When the zinc-bromine flow battery electrolyte migrates from the zinc side to the bromine side, the bromine-side electrolyte will flow back to the zinc-side storage tank through the overflow connecting device, and the bromine inside will react with the zinc plating on the zinc side. Not only will it cause the zinc-bromine flow battery to self-discharge and reduce battery efficiency, but it will also generate a lot of heat, causing the internal temperature of the battery to be too high, affecting the battery life. Summary of the invention

[0003] In view of the above technical problems, the purpose of the utility model is to provide a new overflow connecting device for zinc-bromine flow batteries. A bromine barrier layer is added to the overflow port on the bromine side of the traditional overflow connecting device. When migration occurs and the electrolyte level on the bromine side is higher than the overflow port, the electrolyte on the bromine side flows back to the zinc side storage tank through the overflow connecting device. The bromine barrier layer can block the complex bromine and allow water and other ions to pass through. This not only makes the electrolytes on both sides more balanced, but also avoids self-discharge of the zinc-bromine flow battery.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical solution: a new overflow connecting device applied to zinc-bromine liquid flow battery, comprising an overflow connecting pipe and a bromine barrier layer, one end of the overflow connecting pipe is connected to the zinc side liquid storage tank, and the other end is connected to the bromine side liquid storage tank, and the bromine barrier layer is arranged on the side of the overflow connecting pipe close to the bromine side liquid storage tank.

[0005] The aforementioned novel overflow connecting device applied to zinc-bromine liquid flow battery, the bromine barrier layer comprises a first movable joint, a sealing gasket, a bromine barrier film and a second movable joint; the sealing gasket is respectively arranged between the bromine barrier film and the first movable joint and the second movable joint.

[0006] The aforementioned novel overflow connecting device applied to zinc-bromine liquid flow battery has two ends of the overflow connecting pipe connected to the bromine side liquid storage tank and the zinc side liquid storage tank respectively through hoses.

[0007] The aforementioned novel overflow connecting device applied to zinc-bromine liquid flow battery, the hose is connected to the bromine side liquid storage tank and the zinc side liquid storage tank through a pagoda head.

[0008] In the aforementioned novel overflow connecting device applied to zinc-bromine liquid flow battery, the first movable joint and the second movable joint are plastic movable joints.

[0009] In the aforementioned novel overflow connection device applied to zinc-bromine liquid flow battery, the first movable joint and the second movable joint are welded.

[0010] The aforementioned novel overflow connecting device applied to zinc-bromine liquid flow battery, the sealing gasket is a silicone gasket.

[0011] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0012] 1. The utility model adds a bromine barrier layer in the connecting device, so as to block the complex bromine and allow water and other ions to pass through. This can not only make the electrolytes on both sides more balanced, but also prevent the complex bromine in the electrolyte on the bromine side of the zinc-bromine liquid flow battery from entering the zinc side through the connecting pipe, thereby reducing the self-discharge of the battery, avoiding excessive internal temperature of the battery, and improving the stability and service life of the battery.

[0013] 2. The utility model partially uses hoses for connection in the connecting device, which is not only convenient for disassembly, but also can effectively reduce the damage caused by vibration during transportation and use, and prevent the occurrence of seepage and leakage.

[0014] 3. The utility model uses a plastic joint in the connecting device, which can be welded with other parts by hot melting, has high connection strength, and avoids seepage and leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the initial zinc-bromine storage tank liquid level;

[0016] Figure 2 Schematic diagram of the principle of the overflow communication device applied to the zinc-bromine liquid flow battery in this embodiment;

[0017] Figure 3 It is a front view structural schematic diagram of the overflow communication device applied to the zinc-bromine liquid flow battery of this embodiment;

[0018] Figure 4 It is a schematic diagram of the three-dimensional structure of the overflow communication device applied to the zinc-bromine liquid flow battery in this embodiment;

[0019] Figure 5 It is a schematic diagram of the front view structure of the bromine barrier layer in the overflow communication device of this embodiment;

[0020] Figure 6Schematic diagram of the three-dimensional structure of the bromine barrier layer in the overflow communication device of this embodiment;

[0021] Figure 7 Schematic diagram comparing the coulombic efficiency of the batteries of this embodiment and the comparative example.

[0022] Figure numerals: 1 is the overflow connecting pipe, 2 is the bromine barrier layer, 3 is the bromine side liquid storage tank, 4 is the zinc side liquid storage tank, 5 is the pagoda head, 6 is the hose; 21 is the first flexible joint, 22 is the sealing gasket, 23 is the bromine barrier membrane, and 24 is the second flexible joint. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention is clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0025] Figure 1 The schematic diagram of the initial zinc-bromine storage tank liquid level shows that the liquid levels of the zinc-side storage tank and the bromine-side storage tank are on the same horizontal line. After the zinc-bromine flow battery has been running for a period of time, it will enter the following state: Figure 2 In the situation shown, the liquid level of the bromine side storage tank will be higher than the liquid level of the zinc side storage tank, and the bromine liquid will enter the zinc side storage tank through the connecting pipe. At this time, the bromine will react with the zinc plating on the zinc side, causing the zinc-bromine flow battery to self-discharge and reduce the battery efficiency. It will also generate a lot of heat, causing the internal temperature of the battery to be too high, affecting the battery life.

[0026] like Figure 3 and Figure 4 As shown, in order to avoid the above situation, this embodiment adds a bromine barrier layer to the overflow port on the bromine side of the traditional overflow connecting device. When migration occurs and the electrolyte level on the bromine side is higher than the overflow port, the electrolyte on the bromine side flows back to the zinc side storage tank through the overflow connecting device. The bromine barrier layer can block the complex bromine and allow water and other ions to pass through. This not only makes the electrolytes on both sides more balanced, but also avoids self-discharge of the zinc-bromine flow battery.

[0027] The present embodiment provides a new overflow connecting device applied to a zinc-bromine liquid flow battery, comprising an overflow connecting pipe 1 and a bromine barrier layer 2, wherein one end of the overflow connecting pipe 1 is connected to a zinc-side liquid storage tank 4, and the other end is connected to a bromine-side liquid storage tank 3, and the bromine barrier layer 2 is arranged on the side of the overflow connecting pipe 1 close to the bromine-side liquid storage tank 3.

[0028] like Figure 5 and Figure 6 As shown, preferably, the bromine barrier layer 2 includes a first joint 21, a sealing gasket 22, a bromine barrier film 23 and a second joint 24; the sealing gasket 22 is arranged between the bromine barrier film 23 and the first joint 21 and the second joint 24 respectively.

[0029] Preferably, both ends of the overflow connecting pipe 1 are connected to the bromine side liquid storage tank 3 and the zinc side liquid storage tank 4 through a hose 6 respectively.

[0030] Preferably, the hose 6 is connected to the bromine-side liquid storage tank 3 and the zinc-side liquid storage tank 4 via a pagoda head 5 .

[0031] Preferably, the first joint 21 and the second joint 24 are plastic joints.

[0032] Preferably, the first joint 21 and the second joint 24 are welded.

[0033] Preferably, the sealing pad 22 is a silicone pad.

[0034] Comparative Example: The overflow connecting device is a common connecting device and does not contain a bromine barrier layer.

[0035] Table 1: Battery efficiency comparison table

[0036]

[0037] from Figure 7 As can be seen from Table 1, after adding the bromine barrier layer, the coulomb efficiency of the battery is significantly improved. This is because the addition of the bromine barrier layer in the connecting device can block the complex bromine and allow water and other ions to pass through, which can prevent the complex bromine in the electrolyte on the bromine side of the zinc-bromine flow battery from entering the zinc side through the connecting tube, reducing the battery self-discharge and increasing the battery coulomb efficiency by 5-6 percentage points. The improvement of the battery coulomb efficiency has significantly improved the overall efficiency (energy efficiency) of the battery.

[0038] In this embodiment, a bromine barrier layer is added to the connecting device, thereby blocking complex bromine and allowing water and other ions to pass through. This not only makes the electrolytes on both sides more balanced, but also prevents the complex bromine in the electrolyte on the bromine side of the zinc-bromine flow battery from entering the zinc side through the connecting pipe, thereby reducing the self-discharge of the battery, avoiding excessive internal temperature of the battery, and improving the stability and service life of the battery.

Claims

1. An overflow connection device for zinc-bromine liquid flow battery, characterized in that: It comprises an overflow connecting pipe (1) and a bromine barrier layer (2); one end of the overflow connecting pipe (1) is connected to a zinc-side liquid storage tank (4), and the other end is connected to a bromine-side liquid storage tank (3); and the bromine barrier layer (2) is arranged on a side of the overflow connecting pipe (1) close to the bromine-side liquid storage tank (3).

2. The overflow connection device for zinc-bromine liquid flow battery according to claim 1, characterized in that: The bromine barrier layer (2) comprises a first movable joint (21), a sealing gasket (22), a bromine barrier film (23) and a second movable joint (24); the sealing gasket (22) is arranged between the bromine barrier film (23) and the first movable joint (21) and the second movable joint (24), respectively.

3. The overflow connection device for zinc-bromine liquid flow battery according to claim 1, characterized in that: The two ends of the overflow connecting pipe (1) are respectively connected to the bromine side liquid storage tank (3) and the zinc side liquid storage tank (4) through hoses (6).

4. The overflow connection device for zinc-bromine liquid flow battery according to claim 3, characterized in that: The hose (6) is connected to the bromine side liquid storage tank (3) and the zinc side liquid storage tank (4) through a pagoda head (5).

5. The overflow connection device for zinc-bromine liquid flow battery according to claim 2, characterized in that: The first joint (21) and the second joint (24) are plastic joints.

6. An overflow connection device for zinc-bromine liquid flow battery according to claim 2 or 5, characterized in that: The first movable joint (21) and the second movable joint (24) are welded.

7. The overflow connection device for zinc-bromine liquid flow battery according to claim 2, characterized in that: The sealing pad (22) is a silicone pad.

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