Insulation testing device

Abstract

The utility model discloses an insulation testing device. The insulation testing device is used for testing the insulation resistance of a diaphragm and comprises a host; the first test piece is electrically connected with the host; the first test piece is electrically connected with the main machine, the second test piece is electrically connected with the main machine, the first test piece and the second test piece are oppositely arranged, a containing space used for containing the diaphragm is formed between the first test piece and the second test piece, the first test piece applies voltage to one side of the diaphragm and detects current, and the second test piece is electrically connected with the main machine. And the second test piece applies voltage to the other side of the diaphragm and detects current. The insulation testing device can effectively test the insulation resistance of the diaphragm.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to insulation testing arrangement. BACKGROUND

[0002] As an important component of lithium ion battery, the insulation performance of the diaphragm is crucial to the safety performance of the battery. The main function of the diaphragm is to isolate the positive and negative pole pieces to prevent short circuit caused by the contact of the two poles, and to allow lithium ions to pass through to form a circuit. The performance of the diaphragm directly affects the interface structure, internal resistance, etc. of the battery, and further affects the capacity, cycle performance and safety performance of the battery. In order to improve the performance of the battery, it is necessary to propose a device that can test the insulation performance of the diaphragm. SUMMARY

[0003] The utility model aims at at least one of the technical problems existing in the prior art. To this end, the utility model provides an insulation testing arrangement, which can effectively test the insulation resistance of the diaphragm.

[0004] According to the insulation testing arrangement of the utility model embodiment, the insulation resistance of the diaphragm is tested, comprising:

[0005] A host computer;

[0006] A first test piece is electrically connected to the host computer;

[0007] A second test piece is electrically connected to the host computer, the first test piece and the second test piece are oppositely arranged, and a containing space for placing the diaphragm is formed between the first test piece and the second test piece, the first test piece applies voltage to one side of the diaphragm and detects current, and the second test piece applies voltage to the other side of the diaphragm and detects current.

[0008] According to the insulation testing arrangement of the utility model embodiment, the insulation resistance of the diaphragm can be effectively tested. In this application, the first test piece and the second test piece are arranged on the opposite sides of the diaphragm and press the diaphragm to apply voltage to the diaphragm and detect current, that is, after applying voltage to the diaphragm and detecting current in the diaphragm, the insulation resistance of the diaphragm can be calculated by the ratio of voltage and current. Therefore, the insulation testing arrangement can effectively test the insulation resistance of the diaphragm.

[0009] According to some embodiments of the utility model, a connecting assembly is further included, the connecting assembly connects the first test piece and the second test piece, and the first test piece and the second test piece are both electrically connected to the host computer through the connecting assembly.

[0010] According to some embodiments of the present application, the connecting assembly comprises a first connecting piece and a second connecting piece, two ends of the first connecting piece are electrically connected with the host and the first testing piece respectively, and two ends of the second connecting piece are electrically connected with the host and the second testing piece respectively.

[0011] According to some embodiments of the present application, the insulation testing device comprises a first driving piece and a first guide column, two ends of the first guide column are connected with the first driving piece and the first testing piece respectively, the first driving piece drives the first guide column to move, and the first guide column drives the first testing piece to move close to or away from the second testing piece.

[0012] According to some embodiments of the present application, the insulation testing device comprises a second driving piece and a second guide column, two ends of the second guide column are connected with the second driving piece and the second testing piece respectively, the second driving piece drives the second guide column to move, and the second guide column drives the second testing piece to move close to or away from the first testing piece.

[0013] According to some embodiments of the present application, the first testing piece and the second testing piece are arranged in parallel.

[0014] According to some embodiments of the present application, the first testing piece comprises a first metal plate and a positive active material layer, and the positive active material layer is connected with the first metal plate.

[0015] The second testing piece comprises a second metal plate and a negative active material layer, and the negative active material layer is connected with the second metal plate.

[0016] According to some embodiments of the present application, the resistance of the positive active material layer is R1, and 0.1Ω≤R1≤2Ω.

[0017] According to some embodiments of the present application, the resistance of the negative active material layer is R2, and 0.005Ω≤R2≤0.1Ω.

[0018] According to some embodiments of the present application, the first testing piece comprises a first surface, the first surface is used for abutting against one side of the diaphragm, the area of the first surface is S1, and 0.5cm 2 ≤S1≤225cm 2 ; alternatively, the second testing piece comprises a second surface, the second surface is used for abutting against the other side of the diaphragm, the area of the second surface is S2, and 0.5cm 2 ≤S2≤225cm 2 .

[0019] The additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description of the application. BRIEF DESCRIPTION OF DRAWINGS

[0020] The present application will be further described below in conjunction with the accompanying drawings and embodiments, in which:

[0021] Figure 1 Figure 1 is a schematic view of an insulation testing device of the present application.

[0022] Reference Signs:

[0023] Host 100; first test piece 200; first metal plate 210; positive active material layer 220; first driving piece 230; first guide column 240; second test piece 300; second metal plate 310; negative active material layer 320; connecting assembly 400; first connecting piece 410; second connecting piece 420; support rod 430; first connecting point 431; second connecting point 432. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, in which the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0025] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application.

[0026] In the description of the present application, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0027] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0028] In the description of the utility model, the description of the reference terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0029] As an important component of lithium-ion batteries, the insulation performance of the separator is crucial to the safety performance of the battery. The main function of the separator is to isolate the positive and negative electrode sheets to prevent short circuit caused by contact between the two poles, while allowing lithium ions to pass through to form a circuit. The performance of the separator directly affects the interface structure, internal resistance and other properties of the battery, and further affects the capacity, cycle performance and safety performance of the battery. In order to improve the performance of the battery, it is necessary to propose a device that can test the insulation performance of the separator.

[0030] There are many types of separators, including single-layer PE (polyethylene), single-layer PP (polypropylene), PP / PE / PP composite membrane and composite ceramic separator, etc. The separator material is mostly porous polyolefin, and the preparation method mainly has wet and dry methods, the wet method is also called phase separation method (TIPS), and the dry method is also called melt stretching (MSCS). The separators of different processes differ in structural characteristics, mechanical properties and physicochemical properties, etc. These differences will affect the insulation performance of the separator.

[0031] The characterization of the performance parameters of the separator mainly includes structural characteristics, mechanical properties and physicochemical properties, etc. The structural characteristics include thickness, pore size and distribution, porosity, permeability, micro-morphology and other parameters; the mechanical properties include tensile strength, puncture resistance; the physicochemical properties include wettability and wetting speed, chemical stability, safety protection performance; the thermal performance includes thermal closure temperature, melt rupture temperature, thermal shrinkage rate; the electrochemical performance includes linear voltammetry test (LSV), electrochemical impedance spectroscopy test (EIS), cycle.

[0032] Therefore, in order to ensure that the insulation performance of the separator meets the safety requirements of the battery, a special testing device needs to be designed to accurately evaluate the insulation performance of the separator under actual battery working conditions. This is of great significance to improve the overall performance and safety of the battery.

[0033] Based on the above problems, the present application proposes an insulation testing device, which aims to solve the problems existing in the related art to some extent.

[0034] Reference Figure 1The utility model discloses an insulating test device, which is used for testing the insulation resistance of a diaphragm, and comprises a host computer 100, a first test piece 200 and a second test piece 300. The first test piece 200 is electrically connected to the host computer 100, and the second test piece 300 is electrically connected to the host computer 100. The first test piece 200 and the second test piece 300 are oppositely arranged, and a containing space for placing the diaphragm is formed between the first test piece 200 and the second test piece 300. The first test piece 200 applies a voltage to one side of the diaphragm and detects the current, and the second test piece 300 applies a voltage to the other side of the diaphragm and detects the current.

[0035] The utility model discloses an insulating test device, which is used for testing the insulation resistance of a diaphragm, and comprises a host computer 100, a first test piece 200 and a second test piece 300. The first test piece 200 is electrically connected to the host computer 100, and the second test piece 300 is electrically connected to the host computer 100. The first test piece 200 and the second test piece 300 are oppositely arranged, and a containing space for placing the diaphragm is formed between the first test piece 200 and the second test piece 300. The first test piece 200 applies a voltage to one side of the diaphragm and detects the current, and the second test piece 300 applies a voltage to the other side of the diaphragm and detects the current.

[0036] According to some embodiments of the utility model, the connecting assembly 400 is further connected to the first test piece 200 and the second test piece 300. The first test piece 200 and the second test piece 300 are electrically connected to the host computer 100 through the connecting assembly 400. Specifically, the connecting assembly 400 can provide support for the first test piece 200 and the second test piece 300. Meanwhile, the first connecting piece 410 and the second connecting piece 420 can be electrically connected to the host computer 100 through the connecting assembly 400, and the test voltage and test time can be adjusted on the host computer 100. The diaphragm is placed in the containing space between the first test piece 200 and the second test piece 300, that is, the first test piece 200 and the second test piece 300 are arranged on both sides of the diaphragm. The first test piece 200 and the second test piece 300 press the diaphragm on both sides of the diaphragm to apply pressure and voltage to the diaphragm.

[0037] During the test, the host computer 100 transmits the test voltage to the first test piece 200 through the connecting assembly 400. The first test piece 200 applies a voltage to one side of the diaphragm (the large surface side of the diaphragm) and detects the current of the side. Meanwhile, the host computer 100 transmits the test voltage to the second test piece 300 through the connecting assembly 400. The second test piece 300 applies a voltage to the other side of the diaphragm (the other large surface side of the diaphragm) and tests the current of the side. The insulation resistance of the diaphragm is obtained by calculating the ratio of the applied test voltage and the detected current.

[0038] According to some embodiments of the present application, the connecting assembly 400 comprises a first connecting member 410 and a second connecting member 420, two ends of the first connecting member 410 are respectively electrically connected with the host 100 and the first testing member 200, and two ends of the second connecting member 420 are respectively electrically connected with the host 100 and the second testing member 300. In the present application, the first connecting member 410 is used to electrically connect the host 100 and the first testing member 200, so as to transmit voltage to the first testing member 200, so that the first testing member 200 applies voltage to one side of the diaphragm and detects the current generated on the surface. Similarly, the second connecting member 420 is used to electrically connect the host 100 and the second testing member 300, so as to transmit voltage to the second testing member 300, so that the second testing member 300 applies voltage to the other side of the diaphragm and detects the current generated on the surface. Thus, the insulation resistance of the diaphragm can be simply calculated.

[0039] The first connecting member 410 and the second connecting member 420 can be wires or devices with interfaces for electrical connection, etc. Specifically, in the present application, with reference to Figure 1 , the connecting assembly 400 further comprises a support rod 430, the support rod 430 is provided with a first connecting point 431 and a second connecting point 432, the first connecting member 410 is connected with the first testing member 200 through the first connecting point 431, and the second connecting member 420 is connected with the second testing member 300 through the second connecting point 432, so as to realize the electrical connection of the host 100 with the first testing member 200 and the second testing member 300. It can be understood that the first connecting point 431 and the second connecting point 432 can also be provided as a hole structure, and the first connecting member 410 and the second connecting member 420 are inserted into the internally hollow support rod 430 through the hole, so as to be connected with the first testing member 200 and the second testing member 300 respectively.

[0040] According to some embodiments of the utility model, the insulation testing device comprises a first driving member 230 and a first guide column 240, both ends of the first guide column 240 are connected with the first driving member 230 and the first testing member 200 respectively, the first driving member 230 drives the first guide column 240 to move, and the first guide column 240 drives the first testing member 200 to approach or move away from the second testing member 300. In the application, the insulation testing device is further provided with the first driving member 230 and the first guide column 240, the first driving member 230 drives the first testing member 200 connected with the first guide column 240 to move, so that the first testing member 200 approaches or moves away from the second testing member 300, the accommodation space between the first testing member 200 and the second testing member 300 is reduced, and then the first testing member 200 and the second testing member 300 press the diaphragm on both sides of the diaphragm, and the first testing member 200 and the second testing member 300 apply voltage to both sides of the diaphragm and detect current respectively. Further, in the application, the first testing member 200 and the second testing member 300 can be movable, the second testing member 300 is fixed, or the second testing member 300 is movable, the first testing member 200 is fixed, or both the first testing member 200 and the second testing member 300 are movable.

[0041] The first driving member 230 can be a cylinder, a motor or other driving device, as long as it can drive the first testing member 200 connected with the first guide column 240 to move, and the limitation is not made here.

[0042] According to some embodiments of the utility model, the insulation testing device comprises a second driving member and a second guide column (not shown), both ends of the second guide column are connected with the second driving member and the second testing member 300 respectively, the second driving member drives the second guide column to move, and the second guide column drives the second testing member 300 to approach or move away from the first testing member 200. In addition to the movement of the first testing member 200 to approach or move away from the second testing member 300, the second testing member 300 can also be connected with a second driving frame and a second guide column, which is consistent with the structure and movement principle of the first driving member 230 and the first guide column 240, and the second driving member can drive the second guide column and the second testing member 300 to move away from or approach the first testing member 200. In the testing process, the first testing member 200 and the second testing member 300 can be driven to approach or move away from each other at the same time, so as to press the diaphragm to apply voltage to the diaphragm or loosen the diaphragm to take down the diaphragm.

[0043] The second driving member can be a cylinder, a motor or other driving device, as long as it can drive the second testing member 300 connected with the second guide column to move, and the limitation is not made here.

[0044] Further, as described above, the first test piece 200 and the second test piece 300 can be movable for the first test piece 200, fixed for the second test piece 300, or movable for the second test piece 300, fixed for the first test piece 200, or movable for both the first test piece 200 and the second test piece 300, which can be set according to actual needs, and the present application does not make specific limitations.

[0045] According to some embodiments of the present application, the first test piece 200 and the second test piece 300 are arranged in parallel. In order to enable the first test piece 200 and the second test piece 300 to press the diaphragm tightly and apply voltage on both sides of the diaphragm, and detect the current, the first test piece 200 and the second test piece 300 of the present application are arranged in parallel, so that the first test piece 200 and the second test piece 300 can be better attached to the diaphragm, and the test results can be affected by the uneven gaps between the first test piece 200 and the second test piece 300.

[0046] According to some embodiments of the present application, the first test piece 200 includes a first metal plate 210 and a positive active material layer 220, and the positive active material layer 220 is connected to the first metal plate 210; the second test piece 300 includes a second metal plate 310 and a negative active material layer 320, and the negative active material layer 320 is connected to the second metal plate 310. Specifically, the first metal plate 210 and the positive active material layer 220 act as a positive electrode sheet on one side of the diaphragm, and the second metal plate 310 and the negative active material layer 320 act as a negative electrode sheet on the other side of the diaphragm. When testing the diaphragm between the first test piece 200 and the second test piece 300, the first test piece 200 acts as a positive electrode sheet, and the second test piece 300 acts as a negative electrode sheet, so that the actual insulation resistance of the diaphragm in the battery cell can be simulated. Compared with directly testing the insulation resistance of the diaphragm, the resistance of the diaphragm in the battery cell can be more accurately measured, the accuracy of the insulation capacity evaluation of the diaphragm is improved, and the risk of short circuit of the battery cell caused by insufficient insulation performance of the diaphragm can be avoided, thereby improving the safety and reliability of the battery.

[0047] The first metal plate 210 and the second metal plate 310 can be made of silver, copper, aluminum or other metals. The material of the positive active material layer 220 can be inorganic matter, including but not limited to a mixed coating layer of aluminum oxide, boehmite, magnesium oxide, etc. and carbon black, and the material of the negative active material layer 320 can be graphite.

[0048] According to some embodiments of the present application, the resistance of the positive active material layer 220 is R1, 0.1Ω≤R1≤2Ω. Specifically, the resistance R1 of the positive active material layer 220 should be set in a suitable interval, and should not be too large or too small. Moreover, the resistance of the positive active material layer 220 is related to its material, and too large resistance can make it difficult to apply voltage through the first metal plate 210 to the diaphragm, and it is difficult to control the voltage applied to the diaphragm; too small resistance cannot simulate the state of the diaphragm in the battery cell, affecting the measurement result. Therefore, setting the value range of the resistance R1 between 0.1Ω and 2Ω can further improve the accuracy of the test.

[0049] According to some embodiments of the present application, the resistance of the negative active material layer 320 is R2, 0.005Ω≤R2≤0.1Ω. As with the positive active material layer 220, the resistance of the negative active material layer 320 should also be maintained within a certain range in order to accurately measure the insulation resistance of the diaphragm.

[0050] According to some embodiments of the present application, the first test piece 200 includes a first surface, the first surface being used to abut one side of the diaphragm, the area of the first surface being S1, 0.5cm 2 ≤S1≤225cm 2 ; the second test piece 300 includes a second surface, the second surface being used to abut the other side of the diaphragm, the area of the second surface being S2, 0.5cm 2 ≤S2≤225cm 2 . Specifically, the first surface and the second surface are used to contact the diaphragm, and if the area is set too small, it is difficult to apply voltage to the diaphragm and detect the current of the diaphragm, and if the area is designed too large, it will waste materials and make it inconvenient to measure. Therefore, setting the area S1 of the first surface and the area S2 of the second surface between 0.5cm 2 and 225cm 2 can facilitate measurement and effectively measure the insulation resistance of the diaphragm.

[0051] One embodiment of the present application is:

[0052] The test voltage is set to 100V, the test time is set to 3s, and the contact area is 25cm 2The first test piece 200 uses an aluminum cuboid with a length of 5 cm, a width of 5 cm, and a thickness of 0.5 cm as the first metal plate 210, the positive active material layer 220 is a mixed coating layer coated with aluminum oxide and carbon black, and the resistance of the positive active material layer 220 is 1 Ω. The second test piece 300 uses a copper cuboid with a length of 5.5 cm, a width of 5.5 cm, and a thickness of 0.5 cm as the second metal plate 310, the negative active material layer 320 is a graphite coating layer, and the resistance of the negative active material layer 320 is 0.05 Ω. The size relationship between the separator and the first test piece 200 and the second test piece 300 should satisfy: the area of the separator > the area of the second test piece 300 >= the area of the first test piece. By setting these parameters, the current on both sides of the separator is detected, and the insulation resistance of the separator is obtained by the ratio between the voltage and the current. Therefore, the insulation test device of the application can effectively test the insulation resistance of the separator.

[0053] The embodiments of the utility model are explained in detail above in combination with the drawings, but the utility model is not limited to the above-mentioned embodiments, and various changes can be made within the knowledge range possessed by the ordinary skilled in the art without departing from the purpose of the utility model. In addition, the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

Claims

1. An insulation testing device for testing the insulation resistance of a diaphragm, characterized in that The application relates to an insulation testing device. The device comprises a host, a first testing piece electrically connected to the host, and a second testing piece electrically connected to the host. The first testing piece and the second testing piece are oppositely arranged, and a space for placing a diaphragm is formed between the first testing piece and the second testing piece. The first testing piece applies voltage to one side of the diaphragm and detects current, and the second testing piece applies voltage to the other side of the diaphragm and detects current.

2. The insulation testing device of claim 1, wherein, The device further comprises a connecting assembly connecting the first testing piece and the second testing piece.

3. The insulation testing device of claim 2, wherein, The first testing piece and the second testing piece are electrically connected to the host through the connecting assembly.

4. The insulation testing device of claim 1, wherein, The connecting assembly comprises a first connecting piece and a second connecting piece.

5. The insulation testing device of claim 4, wherein, The two ends of the first connecting piece are electrically connected to the host and the first testing piece respectively, and the two ends of the second connecting piece are electrically connected to the host and the second testing piece respectively.

6. The insulation testing device of claim 1, wherein, The device comprises a first driving piece and a first guide column.

7. The insulation testing device of claim 1, wherein, The two ends of the first guide column are connected to the first driving piece and the first testing piece respectively. The first driving piece drives the first guide column to move, and the first guide column drives the first testing piece to move close to or away from the second testing piece.

8. The insulation testing device of claim 7, wherein, The device comprises a second driving piece and a second guide column.

9. The insulation testing device of claim 7, wherein, The two ends of the second guide column are connected to the second driving piece and the second testing piece respectively. The second driving piece drives the second guide column to move, and the second guide column drives the second testing piece to move close to or away from the first testing piece. The first testing piece and the second testing piece are arranged in parallel. The first testing piece comprises a first metal plate and a positive active material layer. The positive active material layer is connected to the first metal plate. The second testing piece comprises a second metal plate and a negative active material layer. The negative active material layer is connected to the second metal plate. The resistance of the positive active material layer is R1, and 0.1Ω<=R1<=2Ω. The resistance of the negative active material layer is R2, and 0.005Ω<=R2<=0.1Ω.

10. The insulation testing device of claim 1, wherein, The first test piece comprises a first face for abutting against one side of the diaphragm, the area of the first face being S1, 0.5 cm 2 ≤ S1 ≤ 225 cm 2 ; Alternatively, the second test piece comprises a second face for abutting the other side of the septum, the area of the second face being S2, 0.5 cm 2 ≤ S2≤ 225 cm 2 .

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