Device and method for testing air tightness of flow battery

Abstract

The invention relates to a device and a method for testing the air tightness of a flow battery. The device comprises a first sealing plate, a second sealing plate, a first air pump, a first pressure gauge, a second air pump and a second pressure gauge, the first sealing plate and the second sealing plate are oppositely arranged and used for clamping and sealing a to-be-tested electric pile, a first pressurizing hole and a second pressurizing hole are formed in the first sealing plate and the second sealing plate respectively, the first pressurizing hole is used for being communicated with a liquid hole in one side of the to-be-tested electric pile, and the second pressurizing hole is used for being communicated with a liquid hole in the other side of the to-be-tested electric pile; the first air pump and the first pressure gauge are both communicated with the first pressurizing hole; the second air pump and the second pressure gauge are both communicated with the second pressurizing hole. The device can pressurize the two sides of the galvanic pile to be tested at the same time, so that the internal air tightness and the external air tightness of the galvanic pile to be tested can be tested respectively, the internal air tightness and the external air tightness can be tested without replacing the testing device and installing the testing device for multiple times, and the air tightness testing efficiency of the galvanic pile to be tested is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid flow battery detection, and in particular to a liquid flow battery air tightness testing device and a testing method. Background Art

[0002] The large-scale burning of non-renewable energy represented by coal, oil and natural gas has not only brought about an energy crisis, but also caused damage to the earth's ecological environment and an increasingly serious greenhouse effect. Therefore, the efficient use of renewable energy is urgent. In order to improve the energy waste caused by the intermittent and unstable renewable energy such as wind energy and solar energy, the research and development of large-scale energy storage technology is increasingly urgent. As a new type of electrochemical energy storage device, liquid flow battery is regarded as one of the most promising electrochemical energy storage technologies because of its advantages such as capacity and power phase separation, deep charge and discharge, long service life, safety and environmental protection.

[0003] The flow battery stack is the core component of the flow battery system. It is the place where redox reactions occur in the battery system to achieve energy conversion and storage. The working principle of the flow battery is based on electrochemical reactions. Its main feature is that the energy storage medium (electrolyte solution) and the active substances that react are stored separately and transported to the battery stack through a circulation pump to participate in the electrochemical reaction.

[0004] Liquid flow batteries are usually composed of multiple liquid flow battery stacks (referred to as battery stacks) stacked in series. A single battery stack is composed of a negative electrode insulating plate, a negative electrode current collector, a negative electrode, a negative electrode frame, an ion conductive membrane, a positive electrode frame, a positive electrode, a positive current collector and a positive electrode insulating plate, which are manually stacked and pressed together. When the several are assembled, the ion conductive membrane is fixed on the electrode frame, and hot melt adhesive is set between the ion exchange membrane and the electrode frame for sealing.

[0005] Since the electrolyte is a flowing liquid, flow batteries have high requirements for sealing. In order to improve the safety of flow batteries, the gas tightness of the battery stack must be tested. Currently, manual testing of the gas tightness of the battery stack is mostly used. The equipment operation is complicated, the professional requirements for operators are relatively high, and the testing efficiency is low, which cannot meet the company's large-scale production requirements. Summary of the invention

[0006] The purpose of the present invention is to provide a liquid flow battery air tightness testing device and testing method in order to overcome the defects of the above-mentioned prior art and improve the efficiency of battery stack testing.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A liquid flow battery air tightness testing device, comprising:

[0009] a first sealing plate and a second sealing plate, the first sealing plate and the second sealing plate are arranged opposite to each other and used to clamp and seal the battery stack to be tested, the first sealing plate and the second sealing plate are respectively provided with a first pressurizing hole and a second pressurizing hole, the first pressurizing hole is used to communicate with the liquid hole on one side of the battery stack to be tested, and the second pressurizing hole is used to communicate with the liquid hole on the other side of the battery stack to be tested;

[0010] a first air pump and a first pressure gauge, wherein the first air pump and the first pressure gauge are both connected to the first pressurizing hole;

[0011] A second air pump and a second pressure gauge, wherein the second air pump and the second pressure gauge are both connected to the second pressurizing hole.

[0012] In one of the embodiments, a first positioning hole is provided on the battery stack, a positioning column is provided on the first sealing plate, and a second positioning hole is provided on the second sealing plate. The positioning column can pass through the first positioning hole and the second positioning hole.

[0013] In one embodiment, a first sealing gasket is provided between the first sealing plate and the battery stack to be tested;

[0014] A second sealing gasket is provided between the second sealing plate and the battery stack to be tested.

[0015] In one embodiment, a first protrusion is provided on the first sealing plate, a first pressurizing hole is provided in the first protrusion, and a height of the first protrusion is smaller than a height of a liquid hole of the battery stack to be tested;

[0016] The second sealing plate is provided with a second protrusion, a second pressurizing hole is provided in the second protrusion, and the height of the second protrusion is smaller than the height of the liquid hole of the battery stack to be tested.

[0017] In one embodiment, a first air pump communication hole and a first pressure gauge communication hole are provided in the first sealing plate, two ends of the first air pump communication hole are respectively connected to the first pressurizing hole and the first air pump, and two ends of the first pressure gauge communication hole are respectively connected to the first pressurizing hole and the first pressure gauge;

[0018] A second air pump connecting hole and a second pressure gauge connecting hole are provided in the second sealing plate. The two ends of the second air pump connecting hole are respectively connected to the second pressurizing hole and the second air pump. The two ends of the second pressure gauge connecting hole are respectively connected to the second pressurizing hole and the second pressure gauge.

[0019] In one embodiment, the testing device further includes a testing platform and a pressurizing machine, the first sealing plate is connected to the testing platform, and the pressurizing machine is connected to the second sealing plate for driving the second sealing plate to move closer to or away from the first sealing plate.

[0020] A method for testing the air tightness of a flow battery comprises the following specific steps:

[0021] S10: multiple battery stacks are connected in series to obtain a battery stack group to be tested, and the battery stack group to be tested is installed between the first sealing plate and the second sealing plate;

[0022] S20: using the first air pump and the second air pump to pressurize the stack group to be tested and maintain the pressure for a certain period of time to test the air tightness of the stack group to be tested, where the air tightness of the stack group to be tested includes internal air tightness and external air tightness;

[0023] S30: judging the air tightness of the stack to be tested according to the detection values ​​of the first pressure gauge and the second pressure gauge before and after the pressure maintenance;

[0024] S40: If the air tightness of the battery stack group to be tested is qualified, it is determined that the air tightness of all battery stacks included in the battery stack group to be tested is qualified;

[0025] S50: If the air tightness of the battery pack to be tested is unqualified, further determine whether the number of battery packs included in the battery pack to be tested is less than 2; if the number of battery packs included in the battery pack to be tested is less than 2, determine that the air tightness of the battery pack included in the battery pack to be tested is unqualified;

[0026] S60: If the number of battery stacks included in the battery stack group to be tested is greater than or equal to 2, the battery stack group to be tested is divided into two battery stack groups to be tested whose number is greater than or equal to 1, and the two divided battery stack groups to be tested repeat steps S10, S20, S30, S40 and S50 respectively.

[0027] In one embodiment, step S10 includes the following specific steps:

[0028] Connecting the liquid holes of multiple battery stacks in sequence to form a battery stack group to be tested;

[0029] The first pressurizing hole of the first sealing plate is connected to the liquid hole on one side of the battery stack group to be tested, and the second pressurizing hole of the second sealing plate is connected to the liquid hole on the other side of the battery stack group to be tested.

[0030] In one embodiment, step S20 includes the following specific steps:

[0031] Test the external sealing of the stack to be tested: use the first air pump and the second air pump to pressurize the liquid holes on both sides of the stack to be tested at the same time; after the pressurization is completed, record the detection values ​​of the first pressure gauge and the second pressure gauge, which are recorded as the initial pressure P a1 , initial pressure P b1 After maintaining the pressure for a certain period of time, record the detection values ​​of the first pressure gauge and the second pressure gauge, and record them as the final pressure P a2 , Final pressure P b2 ;

[0032] Test the internal sealing of the battery stack to be tested: use the first air pump or the second air pump to pressurize the liquid holes on both sides of the battery stack to be tested; after the pressurization is completed, record the detection value of the first pressure gauge or the second pressure gauge accordingly, recorded as the initial pressure P1; after maintaining the pressure for a certain period of time, record the detection value of the first pressure gauge or the second pressure gauge accordingly, recorded as the final pressure P2.

[0033] In one embodiment, step S30 includes the following specific steps:

[0034] Determine the external air tightness of the battery stack to be tested: compare the initial pressure P a1 and final pressure P a2 The size of the initial pressure P b1 and final pressure P b2 The size of the external sealing of the battery stack to be tested can be judged if the following relationship is satisfied: P a2 ≥αP a1 , and P b2 ≥αP b1 , where α is the external pressure variation coefficient, and 0.8≤α≤1, then the external sealing of the battery stack to be tested is qualified, otherwise the external sealing of the battery stack to be tested is unqualified;

[0035] Determine the internal air tightness of the battery stack to be tested: compare the initial pressure P1 and the final pressure P2. If the following relationship is satisfied: P2 ≥ βP1, where β is the internal qualified pressure variation coefficient, and 0.8 ≤ β ≤ 1, then the internal air tightness of the battery stack to be tested is qualified; otherwise, the internal air tightness of the battery stack to be tested is unqualified.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] 1. The above-mentioned liquid flow battery air tightness testing device is provided with a first sealing plate and a second sealing plate, and the first sealing plate and the second sealing plate are both provided with a first pressurizing hole and a second pressurizing hole connected to the liquid hole of the test battery stack, so that the first air pump and the second air pump can pressurize the liquid hole of the test battery stack through the first sealing plate and the second sealing plate, and then judge the air tightness of the test battery stack by the detection values ​​of the first pressure gauge and the second pressure gauge; internal air tightness refers to the air tightness between the positive and negative electrodes, and external air tightness refers to the air tightness of the sealing structure between different layers of the battery stack, such as the air tightness of the hot melt adhesive between the electrode frame and the ion membrane; since the device can pressurize both sides of the test battery stack at the same time, the internal air tightness and external air tightness of the test battery stack can be tested separately, and the internal air tightness and external air tightness tests can be realized without replacing the test device and multiple installations, which effectively improves the efficiency of the air tightness test of the test battery stack.

[0038] 2. A positioning column is provided on the first sealing plate, and the positioning column can pass through the first positioning hole and the second positioning hole, effectively realizing the installation accuracy between the first sealing plate, the second sealing plate and the fuel cell stack to be tested, ensuring the precise alignment and connection between the first pressurizing hole, the second pressurizing hole and the fuel cell stack to be tested, and improving the installation efficiency of the fuel cell stack to be tested.

[0039] 3. The first sealing gasket and the second sealing gasket are respectively arranged between the first sealing plate and the battery stack to be tested, and between the second sealing plate and the battery stack to be tested, so as to ensure the sealed connection between the first sealing plate, the second sealing plate and the battery stack to be tested, and avoid air leakage between the first sealing plate, the second sealing plate and the battery stack to be tested, which may affect the accuracy of the air tightness test.

[0040] 4. The first sealing plate and the second sealing plate are respectively provided with a first protrusion and a second protrusion, so that the first protrusion and the second protrusion can extend into the liquid hole of the battery stack to be tested, and the first pressurizing hole and the second pressurizing hole can be connected with the liquid hole of the battery stack to be tested, thereby improving the sealing between the first pressurizing hole and the second pressurizing hole and the liquid hole of the battery stack to be tested.

[0041] 5. The above-mentioned liquid flow battery air tightness test method can not only test the internal air tightness and external air tightness of multiple test stacks at the same time, but also can gradually screen out the test stacks with unqualified air tightness through dichotomy. It is not necessary to test each test stack to screen out all unqualified stacks, which effectively improves the efficiency of industrial air tightness testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a cross-sectional view of the air tightness testing device in the present invention.

[0043] Figure 2 It is a top view of the battery stack group to be tested in the present invention.

[0044] Figure 3 It is a flow chart of the air tightness testing method in the present invention.

[0045] Figure numerals: 100, airtightness test device; 10, first sealing plate; 20, second sealing plate; 30, positioning column; 40, test platform; 50, pressurizing machine; 60, first sealing gasket; 70, fuel cell stack to be tested; 71, fuel cell stack; 72, liquid hole. DETAILED DESCRIPTION

[0046] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0047] The following figures describe in detail a liquid flow battery air tightness testing device 100 and a testing method in some embodiments.

[0048] like Figure 1 and Figure 2 As shown, in one embodiment, a flow battery air tightness testing device 100 is provided, comprising a first sealing plate 10 and a second sealing plate 20, a first air pump and a first pressure gauge, a second air pump and a second pressure gauge;

[0049] Among them, the first sealing plate 10 and the second sealing plate 20 are arranged opposite to each other, and are used to clamp and seal the battery stack to be tested 71. The first sealing plate 10 and the second sealing plate 20 are respectively provided with a first pressurizing hole and a second pressurizing hole. The first pressurizing hole is used to communicate with the liquid hole 72 on one side of the battery stack to be tested 71, and the second pressurizing hole is used to communicate with the liquid hole 72 on the other side of the battery stack to be tested 71; the first air pump and the first pressure gauge are both connected to the first pressurizing hole; the second air pump and the second pressure gauge are both connected to the second pressurizing hole.

[0050] The above-mentioned liquid flow battery air tightness testing device 100 is provided with a first sealing plate 10 and a second sealing plate 20, and the first sealing plate 10 and the second sealing plate 20 are both provided with a first pressurizing hole and a second pressurizing hole connected to the liquid hole 72 of the test battery stack 71, so that the first air pump and the second air pump can pressurize the liquid hole 72 of the test battery stack 71 through the first sealing plate 10 and the second sealing plate 20, and then judge the air tightness of the test battery stack 71 by the detection values ​​of the first pressure gauge and the second pressure gauge; internal air tightness refers to the air tightness between the positive and negative electrodes, such as ion membrane perforation; external air tightness refers to the air tightness of the sealing structure between different layers of the battery stack 71, such as poor hot melt adhesive sealing between the electrode frame and the ion membrane; since the device can pressurize both sides of the test battery stack 71 at the same time, the internal air tightness and external air tightness of the test battery stack 71 can be tested separately, and the internal air tightness and external air tightness tests can be realized without replacing the test device and multiple installations, which effectively improves the air tightness test efficiency of the test battery stack 71.

[0051] Specifically, Figure 1 As shown, in one embodiment, a first positioning hole is provided on the battery stack 71, a positioning column 30 is provided on the first sealing plate 10, and a second positioning hole is provided on the second sealing plate 20. The positioning column 30 can pass through the first positioning hole and the second positioning hole.

[0052] The first sealing plate 10 is provided with a positioning column 30, which can pass through the first positioning hole and the second positioning hole, effectively realizing the installation accuracy between the first sealing plate 10, the second sealing plate 20 and the battery stack 71 to be tested, ensuring the precise alignment and connection between the first pressurizing hole, the second pressurizing hole and the battery stack 71 to be tested, and improving the installation efficiency of the battery stack 71 to be tested.

[0053] Specifically, Figure 2As shown, in one embodiment, a first sealing gasket 60 is provided between the first sealing plate 10 and the test stack 71 ; and a second sealing gasket is provided between the second sealing plate 20 and the test stack 71 .

[0054] The first sealing gasket 60 and the second sealing gasket are respectively arranged between the first sealing plate 10 and the battery stack to be tested 71, and between the second sealing plate 20 and the battery stack to be tested 71, so as to ensure the sealed connection between the first sealing plate 10, the second sealing plate 20 and the battery stack to be tested 71, and avoid air leakage between the first sealing plate 10, the second sealing plate 20 and the battery stack to be tested 71, which may affect the accuracy of the air tightness test.

[0055] Specifically, in one embodiment, a first protrusion is provided on the first sealing plate 10, a first pressurizing hole is provided in the first protrusion, and the height of the first protrusion is less than the height of the liquid hole 72 of the test stack 71; a second protrusion is provided on the second sealing plate 20, a second pressurizing hole is provided in the second protrusion, and the height of the second protrusion is less than the height of the liquid hole 72 of the test stack 71. The diameters of the first protrusion and the second protrusion are smaller than the liquid hole 72 of the test stack 71, so the first protrusion and the second protrusion extend into the liquid hole 72 of the test stack 71.

[0056] Among them, the diameter of the first protrusion and the second protrusion is smaller than the diameter of the liquid hole 72 of the battery stack to be tested 71, and the first protrusion and the second protrusion are respectively provided on the first sealing plate 10 and the second sealing plate 20, so that the first protrusion and the second protrusion can extend into the liquid hole 72 of the battery stack to be tested 71, and the first pressurizing hole and the second pressurizing hole are connected with the liquid hole 72 of the battery stack to be tested 71, thereby improving the sealing between the first pressurizing hole, the second pressurizing hole and the liquid hole 72 of the battery stack to be tested 71.

[0057] Further, in one embodiment, a first air pump communication hole and a first pressure gauge communication hole are provided in the first sealing plate 10, and two ends of the first air pump communication hole are respectively connected to the first pressurizing hole and the first air pump, and two ends of the first pressure gauge communication hole are respectively connected to the first pressurizing hole and the first pressure gauge;

[0058] In addition, a second air pump connecting hole and a second pressure gauge connecting hole are provided in the second sealing plate 20, and both ends of the second air pump connecting hole are respectively connected to the second pressurizing hole and the second air pump, and both ends of the second pressure gauge connecting hole are respectively connected to the second pressurizing hole and the second pressure gauge.

[0059] like Figure 1 As shown, in this specific embodiment, the first air pump is connected to the first air pump connecting hole through the air pump pipeline, and the second air pump is connected to the second air pump connecting hole through the air pump pipeline.

[0060] Specifically, Figure 1As shown, in one embodiment, the testing device further includes a testing platform 40 and a pressurizing machine 50 , the first sealing plate 10 is connected to the testing platform 40 , and the pressurizing machine 50 is connected to the second sealing plate 20 , for driving the second sealing plate 20 to move closer to or away from the first sealing plate 10 .

[0061] like Figure 3 As shown, in one embodiment, a method for testing the air tightness of a flow battery is provided, comprising the following specific steps:

[0062] S10: multiple battery stacks 71 are connected in series to obtain a battery stack group 70 to be tested, and the battery stack group 70 to be tested is installed between the first sealing plate 10 and the second sealing plate 20;

[0063] S20: using the first air pump and the second air pump to pressurize the test stack group 70 and maintain the pressure for a certain period of time to test the air tightness of the test stack group 70. The air tightness of the test stack group 70 includes internal air tightness and external air tightness.

[0064] S30: judging the air tightness of the test stack 70 according to the detection values ​​of the first pressure gauge and the second pressure gauge before and after the pressure maintenance;

[0065] S40: If the air tightness of the test stack group 70 is qualified, it is determined that the air tightness of all the stacks 71 included in the test stack group 70 is qualified;

[0066] S50: If the air tightness of the test stack group 70 is unqualified, further determine whether the number of the battery stacks 71 included in the test stack group 70 is less than 2; if the number of the battery stacks 71 included in the test stack group 70 is less than 2, it is determined that the air tightness of the battery stack 71 included in the test stack group 70 is unqualified;

[0067] S60: If the number of the battery stacks 71 included in the battery stack group 70 to be tested is greater than or equal to 2, the battery stack group 70 to be tested is divided into two battery stack groups 70 to be tested whose number is greater than or equal to 1, and the two divided battery stack groups 70 to be tested repeat steps S10, S20, S30, S40 and S50 respectively.

[0068] The above-mentioned liquid flow battery air tightness testing method can not only simultaneously test the internal air tightness and external air tightness of multiple test stacks 71, but also gradually screen out the test stacks 71 with unqualified air tightness through dichotomy. All unqualified stacks can be screened out without testing each test stack 71, which effectively improves the efficiency of industrial air tightness testing.

[0069] Specifically, in one embodiment, step S10 includes the following specific steps:

[0070] Connecting the liquid holes 72 of the plurality of battery stacks 71 in sequence to form a battery stack group 70 to be tested;

[0071] The first pressurizing hole of the first sealing plate 10 is connected to the liquid hole 72 on one side of the test stack group 70, and the second pressurizing hole of the second sealing plate 20 is connected to the liquid hole 72 on the other side of the test stack group 70;

[0072] Specifically, in one embodiment, step S20 includes the following specific steps:

[0073] Test the external sealing of the stack group 70 to be tested: Use the first air pump and the second air pump to pressurize the liquid holes 72 on both sides of the stack group 70 to be tested at the same time; after the pressurization is completed, record the detection values ​​of the first pressure gauge and the second pressure gauge, which are recorded as the initial pressure P a1 , initial pressure P b1 After maintaining the pressure for a certain period of time, record the detection values ​​of the first pressure gauge and the second pressure gauge, and record them as the final pressure P a2 , Final pressure P b2 ;

[0074] Test the internal sealing of the test stack group 70: Use the first air pump or the second air pump to pressurize the liquid holes 72 on both sides of the test stack group 70; after the pressurization is completed, the detection value of the first pressure gauge or the second pressure gauge is recorded accordingly, recorded as the initial pressure P1; after maintaining the pressure for a certain period of time, the detection value of the first pressure gauge or the second pressure gauge is recorded accordingly, recorded as the final pressure P2;

[0075] Furthermore, in one embodiment, step S30 includes the following specific steps:

[0076] Determine the external air tightness of the stack group 70 to be tested: compare the initial pressure P a1 and final pressure P a2 The size of the initial pressure P b1 and final pressure P b2 The size of the external sealing of the stack group 70 to be tested is determined if the following relationship is satisfied: P a2 ≥αP a1 , and P b2 ≥αP b1 , where α is the external pressure variation coefficient, and 0.8≤α≤1, the external sealing performance of the tested stack group 70 is qualified, otherwise the external sealing performance of the tested stack group 70 is unqualified;

[0077] Determine the internal air tightness of the test stack group 70: compare the initial pressure P1 and the final pressure P2. If the following relationship is satisfied: P2≥βP1, where β is the internal qualified pressure variation coefficient, and 0.8≤β≤1, then the internal airtightness of the test stack group 70 is qualified, otherwise the internal airtightness of the test stack group 70 is unqualified.

[0078] Example 1

[0079] S10: connecting the liquid holes 72 of the ten battery stacks 71 in sequence to form a battery stack group 70 to be tested; connecting the first pressurizing hole of the first sealing plate 10 to the liquid hole 72 on one side of the battery stack group 70 to be tested, and connecting the second pressurizing hole of the second sealing plate 20 to the liquid hole 72 on the other side of the battery stack group 70 to be tested;

[0080] S20:

[0081] Test the external sealing of the stack group 70 to be tested: Use the first air pump and the second air pump to pressurize the liquid holes 72 on both sides of the stack group 70 to be tested by 100 kPa at the same time; after the pressurization is completed, record the detection values ​​of the first pressure gauge and the second pressure gauge, which are recorded as the initial pressure P a1 (100kPa), initial pressure P b1 (100kPa); after maintaining the pressure for 15 minutes, record the detection values ​​of the first pressure gauge and the second pressure gauge, and record them as the final pressure P a2 (99kPa), final pressure P b2 (100kPa);

[0082] Test the internal sealing of the stack group 70 to be tested: use the first air pump to pressurize the liquid holes 72 on both sides of the stack group 70 to be tested by 50 kPa; after the pressurization is completed, record the detection value of the first pressure gauge, which is recorded as the initial pressure P1 (50 kPa); after maintaining the pressure for 10 minutes, record the detection value of the first pressure gauge, which is recorded as the final pressure P2 (10 kPa);

[0083] S30:

[0084] Determine the external air tightness of the stack group 70 to be tested: α is 0.8, P a2 ≥0.8P a1 , and P b2 ≥0.8P b1 , therefore, the external sealing of the tested stack group 70 is qualified;

[0085] Determine the internal air tightness of the test stack group 70: β is 0.8, P2<βP1, and the internal air tightness of the test stack group 70 is unqualified.

[0086] S60: If the number of the battery stacks 71 included in the battery stack group 70 to be tested is greater than or equal to 2, the battery stack group 70 to be tested is divided into two battery stack groups 70 to be tested (referred to as the first group and the second group) with a number equal to 5, and the first group and the second group repeat steps S10, S20, S30, S40 and S50 to test the internal air tightness of the first group and the second group;

[0087] Finally, it was measured that the internal airtightness of the first group was qualified, and it was determined that the internal airtightness of all the battery stacks included in the first group was qualified, and the internal airtightness of the second group was unqualified. The second group was divided into 2 third groups of battery stacks 70 to be tested and 3 third groups of battery stacks 70 to be tested (referred to as the third group and the fourth group), and the internal airtightness of the fourth group was qualified, and all the battery stacks in the fourth group were determined to be qualified, and the internal airtightness of the third group was unqualified. The third group was divided into 1 fifth group and 1 sixth group, and finally it was measured that the internal airtightness of the fifth group was qualified, the internal airtightness of one battery stack in the fifth group was qualified, the internal airtightness of the sixth group was unqualified, and the internal airtightness of one battery stack in the sixth group was unqualified.

[0088] Example 2

[0089] S10: connecting the liquid holes 72 of the ten battery stacks 71 in sequence to form a battery stack group 70 to be tested; connecting the first pressurizing hole of the first sealing plate 10 to the liquid hole 72 on one side of the battery stack group 70 to be tested, and connecting the second pressurizing hole of the second sealing plate 20 to the liquid hole 72 on the other side of the battery stack group 70 to be tested;

[0090] S20:

[0091] Test the external sealing of the stack group 70 to be tested: Use the first air pump and the second air pump to pressurize the liquid holes 72 on both sides of the stack group 70 to be tested by 100 kPa at the same time; after the pressurization is completed, record the detection values ​​of the first pressure gauge and the second pressure gauge, which are recorded as the initial pressure P a1 (100kPa), initial pressure P b1 (100kPa); after maintaining the pressure for 15 minutes, record the detection values ​​of the first pressure gauge and the second pressure gauge, and record them as the final pressure P a2 (99kPa), final pressure P b2 (75kPa);

[0092] Test the internal sealing of the test stack group 70: Use the second air pump to pressurize the liquid holes 72 on both sides of the test stack group 70 by 50 kPa; after the pressurization is completed, record the detection value of the second pressure gauge, which is recorded as the initial pressure P1 (50 kPa); after maintaining the pressure for 10 minutes, record the detection value of the second pressure gauge, which is recorded as the final pressure P2 (50 kPa);

[0093] S30:

[0094] Determine the external air tightness of the stack group 70 to be tested: α is 0.8, P a2 ≥0.8P a1 , P b2 <0.8P b1 Therefore, the external sealing of the tested stack group 70 is unqualified;

[0095] Determine the internal air tightness of the test stack group 70: β is 0.8, P2≥0.8P1, and the internal air tightness of the test stack group 70 is qualified.

[0096] S60: If the number of the battery stacks 71 included in the battery stack group 70 to be tested is greater than or equal to 2, the battery stack group 70 to be tested is divided into two battery stack groups 70 to be tested (referred to as the first group and the second group) with a number equal to 5, and the first group and the second group repeat steps S10, S20, S30, S40 and S50 to test the external air tightness of the first group and the second group;

[0097] Finally, it was measured that the external airtightness of the first group was qualified, and the internal airtightness of all the battery stacks included in the first group was determined to be qualified, and the external airtightness of the second group was unqualified. The second group was divided into 2 third groups of battery stacks 70 to be tested and 3 third groups of battery stacks 70 to be tested (referred to as the third group and the fourth group), and the external airtightness of the fourth group was qualified, and all the battery stacks in the fourth group were determined to be qualified, and the external airtightness of the third group was unqualified. The third group was divided into 1 fifth group and 1 sixth group, and finally it was measured that the external airtightness of the fifth group was qualified, one battery stack in the fifth group was qualified, the external airtightness of the sixth group was unqualified, and one battery stack in the sixth group was unqualified.

[0098] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0099] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0100] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0101] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0102] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0103] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A liquid flow battery air tightness test device, characterized in that: include: A first sealing plate (10) and a second sealing plate (20), the first sealing plate (10) and the second sealing plate (20) being arranged opposite to each other and used to clamp and seal the battery stack (71) to be tested, the first sealing plate (10) and the second sealing plate (20) being provided with a first pressurizing hole and a second pressurizing hole respectively, the first pressurizing hole being used to communicate with a liquid hole (72) on one side of the battery stack (71) to be tested, and the second pressurizing hole being used to communicate with a liquid hole (72) on the other side of the battery stack (71) to be tested; a first air pump and a first pressure gauge, wherein the first air pump and the first pressure gauge are both connected to the first pressurizing hole; A second air pump and a second pressure gauge, wherein the second air pump and the second pressure gauge are both connected to the second pressurizing hole.

2. A liquid flow battery air tightness testing device according to claim 1, characterized in that: The battery stack (71) is provided with a first positioning hole, the first sealing plate (10) is provided with a positioning column (30), and the second sealing plate (20) is provided with a second positioning hole, and the positioning column (30) can pass through the first positioning hole and the second positioning hole.

3. A liquid flow battery air tightness testing device according to claim 1, characterized in that: A first sealing gasket (60) is provided between the first sealing plate (10) and the battery stack (71) to be tested; A second sealing gasket is provided between the second sealing plate (20) and the test stack (71).

4. A liquid flow battery air tightness testing device according to claim 1, characterized in that: The first sealing plate (10) is provided with a first protrusion, a first pressurizing hole is provided in the first protrusion, and the height of the first protrusion is smaller than the height of the liquid hole (72) of the test stack (71); The second sealing plate (20) is provided with a second protrusion, a second pressurizing hole is provided in the second protrusion, and the height of the second protrusion is smaller than the height of the liquid hole (72) of the test stack (71).

5. A liquid flow battery air tightness testing device according to claim 4, characterized in that: The first sealing plate (10) is provided with a first air pump communicating hole and a first pressure gauge communicating hole, the two ends of the first air pump communicating hole are respectively connected to the first pressurizing hole and the first air pump, and the two ends of the first pressure gauge communicating hole are respectively connected to the first pressurizing hole and the first pressure gauge; The second sealing plate (20) is provided with a second air pump connecting hole and a second pressure gauge connecting hole, the two ends of the second air pump connecting hole are respectively connected to the second pressurizing hole and the second air pump, and the two ends of the second pressure gauge connecting hole are respectively connected to the second pressurizing hole and the second pressure gauge.

6. A liquid flow battery air tightness testing device according to claim 1, characterized in that: The testing device further comprises a testing platform (40) and a pressurizing machine (50), wherein the first sealing plate (10) is connected to the testing platform (40), and the pressurizing machine (50) is connected to the second sealing plate (20) and is used to drive the second sealing plate (20) to move closer to or away from the first sealing plate (10).

7. A method for testing the air tightness of a flow battery, characterized in that: The specific steps include: S10: multiple battery stacks (71) are connected in series to obtain a battery stack group (70) to be tested, and the battery stack group (70) to be tested is installed between a first sealing plate (10) and a second sealing plate (20); S20: using a first air pump and a second air pump to pressurize the test stack group (70) and maintain the pressure for a certain period of time, to test the air tightness of the test stack group (70), wherein the air tightness of the test stack group (70) includes internal air tightness and external air tightness; S30: judging the air tightness of the test stack group (70) according to the detection values ​​of the first pressure gauge and the second pressure gauge before and after the pressure maintenance; S40: If the air tightness of the battery stack group (70) to be tested is qualified, it is determined that the air tightness of all battery stacks (71) included in the battery stack group (70) to be tested is qualified; S50: if the air tightness of the battery pack group (70) to be tested is unqualified, further determining whether the number of battery packs (71) included in the battery pack group (70) to be tested is less than 2; if the number of battery packs (71) included in the battery pack group (70) to be tested is less than 2, determining that the air tightness of the battery pack (71) included in the battery pack group (70) to be tested is unqualified; S60: If the number of battery stacks (71) included in the battery stack group (70) to be tested is greater than or equal to 2, the battery stack group (70) to be tested is divided into two battery stack groups (70) to be tested, the number of which is greater than or equal to 1, and the two divided battery stack groups (70) to be tested respectively repeat step S10, step S20, step S30, step S40 and step S50.

8. A method for testing the air tightness of a flow battery according to claim 7, characterized in that: The step S10 includes the following specific steps: The liquid holes (72) of a plurality of battery stacks (71) are connected in sequence to form a battery stack group (70) to be tested; The first pressurizing hole of the first sealing plate (10) is connected to the liquid hole (72) on one side of the battery stack group (70) to be tested, and the second pressurizing hole of the second sealing plate (20) is connected to the liquid hole (72) on the other side of the battery stack group (70) to be tested.

9. A method for testing the air tightness of a flow battery according to claim 7, characterized in that: The step S20 includes the following specific steps: Testing the external sealing performance of the test stack group (70): using a first air pump and a second air pump to simultaneously pressurize the liquid holes (72) on both sides of the test stack group (70); after the pressurization is completed, recording the detection values ​​of the first pressure gauge and the second pressure gauge, and recording them as the initial pressure P a1 , initial pressure P b1 After maintaining the pressure for a certain period of time, record the detection values ​​of the first pressure gauge and the second pressure gauge, and record them as the final pressure P a2 , Final pressure P b2 ; Testing the internal sealing performance of the test stack group (70): using a first air pump or a second air pump to pressurize the liquid holes (72) on both sides of the test stack group (70); after the pressurization is completed, the detection value of the first pressure gauge or the second pressure gauge is recorded accordingly, recorded as the initial pressure P1; after maintaining the pressure for a certain period of time, the detection value of the first pressure gauge or the second pressure gauge is recorded accordingly, recorded as the final pressure P2.

10. A method for testing the air tightness of a flow battery according to claim 9, characterized in that: The step S30 includes the following specific steps: Determine the external air tightness of the test stack group (70): compare the initial pressure P a1 and final pressure P a2 The size of the initial pressure P b1 and final pressure P b2 The size of the external sealing of the stack group (70) to be tested is determined if the following relationship is satisfied: P a2 ≥αP a1 , and P b2 ≥αP b1 , wherein α is the external pressure variation coefficient, and 0.8≤α≤1, then the external sealing performance of the tested battery stack group (70) is qualified, otherwise the external sealing performance of the tested battery stack group (70) is unqualified; Determine the internal air tightness of the test stack group (70): compare the initial pressure P1 and the final pressure P2. If the following relationship is satisfied: P2 ≥ βP1, where β is the internal qualified pressure variation coefficient, and 0.8 ≤ β ≤ 1, then the internal air tightness of the test stack group (70) is qualified; otherwise, the internal air tightness of the test stack group (70) is unqualified.

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