Method for testing electrostatic discharge of diaphragm

Abstract

The invention discloses a method for testing electrostatic discharge of a diaphragm. The method comprises the following steps: S1, placing a to-be-detected diaphragm without static electricity on a vertical insulating plate; s2, a conductive terminal is placed on one side of the to-be-detected diaphragm, a discharge terminal is placed on the second side of the to-be-detected diaphragm, the discharge terminal is opposite to the conductive terminal, and the to-be-detected diaphragm opposite to the conductive terminal and the discharge terminal is a to-be-detected area; s3, the conductive terminal is grounded through the coupling plate, the electrostatic generator makes vertical contact with the discharge terminal, and static electricity is applied to the discharge terminal, so that electrostatic discharge testing is conducted on the diaphragm of the to-be-detected area; and S4, detecting the damage or breakdown condition of the diaphragm to be detected. According to the invention, the discharge state of the diaphragm in the actual processing and using process is simulated, the electrostatic discharge test of the diaphragm can be realized without diaphragm breakdown, and the electrostatic discharge performance of the diaphragm can be screened in the early stage.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic discharge testing of diaphragm materials, and in particular to a method for testing electrostatic discharge of diaphragms. Background Art

[0002] The diaphragm is an important component of the battery cell. The quality of the diaphragm directly determines the quality of the battery cell. Damage to the diaphragm caused by static electricity will directly lead to a short circuit in the battery cell or a degradation of the performance of the battery cell after a long cycle. Electrostatic discharge (ESD) is a test method to verify the anti-static interference performance of the product.

[0003] At present, the industry has not conducted electrostatic discharge tests on diaphragms, and the ability of diaphragms to resist electrostatic interference is unknown. Therefore, studying the electrostatic discharge test technology of diaphragms is of great significance to improving the quality of battery cells.

[0004] After searching, the Chinese patent with patent application number: 202110986274.2 and patent name "A lithium battery diaphragm electrostatic breakdown test device" discloses a method that can effectively test the electrostatic breakdown voltage of the diaphragm, and can also measure the voltage changes during the electrostatic breakdown of the film. This detection is a detection of the breakdown of the diaphragm, but the breakdown point and damage of the diaphragm are unknown. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention provides a test method for electrostatic discharge of a diaphragm.

[0006] The present invention provides a method for testing electrostatic discharge of a diaphragm, comprising the following steps:

[0007] S1. Placing a non-statically-charged diaphragm to be tested on an insulating plate. Specifically, the non-static performance of the diaphragm to be tested can be achieved by eliminating the static electricity of the diaphragm to be tested.

[0008] S2, placing the conductive terminal on one side of the diaphragm to be detected, placing the discharge terminal on the second side of the diaphragm to be detected, the discharge terminal is opposite to the conductive terminal, and the diaphragm to be detected opposite to the conductive terminal and the discharge terminal is the detection area, and a first gap is formed between the diaphragm to be detected and the conductive terminal, and a second gap is formed between the diaphragm to be detected and the discharge terminal;

[0009] S3, the conductive terminal is grounded, the electrostatic generator is in vertical contact with the discharge terminal and the discharge terminal is statically charged to achieve the electrostatic discharge test of the diaphragm to be tested;

[0010] S4. Detect the damage of the diaphragm to be detected.

[0011] As a further optimized solution of the present invention, step S1 also includes cutting the membrane sample to be tested, and wearing an anti-static wristband while cutting the membrane sample to be tested.

[0012] Cut the membrane samples to be tested to facilitate the electrostatic discharge test, and wear an anti-static wristband to prevent static electricity on the body from being transferred to the membrane samples to be tested to ensure test accuracy.

[0013] As a further optimized solution of the present invention, step S1 also includes detecting the surface condition of the diaphragm to be detected before eliminating the static electricity of the diaphragm to be detected to ensure that the diaphragm to be detected is intact, and comparing the damage condition of the diaphragm detected after the electrostatic discharge test with the condition of the diaphragm before the electrostatic discharge test to determine the anti-static discharge performance of the diaphragm.

[0014] As a further optimized solution of the present invention, the outer diameter of the end of the conductive terminal opposite to the diaphragm to be detected in step S2 gradually increases from the end close to the diaphragm to be detected to the end away from the diaphragm to be detected; and / or

[0015] The outer diameter of the end of the discharge terminal opposite to the diaphragm to be detected gradually increases from the end close to the diaphragm to be detected to the end far away from the diaphragm to be detected.

[0016] Preferably, the end of the conductive terminal opposite to the diaphragm to be detected is conical, the end of the discharge terminal opposite to the detection diaphragm is conical, and the tips of the conductive terminal and the discharge terminal are opposite to the diaphragm to be detected, thereby increasing the electrostatic discharge test effect.

[0017] As a further optimized solution of the present invention, step S3 also includes adjusting the position of the diaphragm to be detected to change the area to be detected, so as to facilitate detection of different positions of the diaphragm to be detected and improve detection accuracy.

[0018] As a further optimized solution of the present invention, in step S3, the conductive terminal is connected to the tooling coupling plate and then grounded.

[0019] Further increase the electronic grounding effect of the conductive terminal.

[0020] Specifically, in some embodiments, in step S4, the damage of the diaphragm to be inspected is detected by an optical microscope.

[0021] Of course, those skilled in the art can also use a magnifying glass or other tools to observe the damage to the diaphragm to be tested, and an optical microscope has relatively higher accuracy.

[0022] As a further optimized solution of the present invention, step S1 also includes testing the air permeability of the membrane to be tested by an air permeability tester;

[0023] The detection of the membrane to be detected in step S4 also includes detecting the air permeability of the membrane to be detected.

[0024] The air permeability of the diaphragm after the electrostatic discharge test can be used to judge the electrostatic discharge performance of the diaphragm from another perspective.

[0025] Specifically, the damage condition of the diaphragm in step S4 includes the damage diameter, the damage area, the breakdown diameter and the breakdown area.

[0026] Compared with the prior art diaphragm electrostatic discharge test which requires the diaphragm to be punctured before its performance can be judged, the present invention can judge the diaphragm electrostatic discharge performance without puncturing the diaphragm.

[0027] As a further optimized solution of the present invention, in step S2, the distance between the conductive terminal and the diaphragm to be detected is 1 mm-20 mm; and / or

[0028] The distance from the discharge terminal to the diaphragm to be detected is 1 mm-20 mm. In some embodiments, the distance from the conductive terminal to the detection diaphragm is equal to the distance from the discharge terminal to the detection diaphragm.

[0029] Facilitates electrostatic discharge testing.

[0030] In the present invention, the proposed test method for the electrostatic discharge of the diaphragm can realize the electrostatic discharge test of the diaphragm without the need for diaphragm breakdown; and it simulates the discharge state of the diaphragm during actual processing and use, so the electrostatic discharge performance of the diaphragm can be screened in the early stage, thereby improving the quality of the diaphragm and further improving the quality of the battery cell.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of the device used in the present invention;

[0033] In the figure: 1. workbench; 2. first clamping member; 3. second clamping member; 4. first moving mechanism; 5. second moving mechanism; 6. conductive terminal; 7. discharge terminal; 8. electrostatic generator; 9. coupling plate; 10. diaphragm to be tested. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] A method for testing electrostatic discharge of a diaphragm, using Figure 1The device shown in the figure comprises a workbench 1 with an insulating plate, a first clamping member 2 and a second clamping member 3 are provided on the workbench 1, the first clamping member 2 and the second clamping member 3 are used to fix the diaphragm 10 to be detected, specifically, the first clamping member 2 and the second clamping member are both provided with through holes, specifically, the first clamping member 2 and the second clamping member 3 are detachably connected by a clamping method, and the diaphragm 10 to be detected is located between the first clamping member 2 and the second clamping member 3, and the portion of the diaphragm 10 to be detected located at the through hole is fixed to ensure that the diaphragm 10 to be detected is close to the insulation of the workbench. The plates have a certain distance, preferably, the first clamping member 2 and the second clamping member 3 are made of insulating materials; the first clamping member 2 and the second clamping member 3 are slidably installed on the workbench 1, specifically, a slide groove is opened on the workbench 1, the first clamping member 2 and the second clamping member 3 slide in the slide groove, the slide groove is arranged to facilitate the clamping of the diaphragm 10 to be detected between the first clamping member 2 and the second clamping member 3 to a certain extent, and also includes a moving mechanism, the moving mechanism is used to drive the first clamping member 2 and the second clamping member 3 to move, thereby realizing the change of the position of the diaphragm 10 to be detected on the workbench 1;

[0036] Specifically, the moving mechanism includes a first moving mechanism 4 on one side of the first clamping member 2 and the second clamping member 3 and a second moving mechanism 5 installed on the other side of the first clamping member 2 and the second clamping member 3. The first moving mechanism 4 and the second moving mechanism 5 are opposite to each other, and the first moving mechanism 4 and the second moving mechanism 5 act synchronously to drive the first clamping member 2 and the second clamping member 3 to move. Specifically, the first moving mechanism 4 and the second moving mechanism 5 are both screws. The first moving mechanism 4 is in conflict with one side of the first clamping member 2 and the second clamping member 3, and the second moving mechanism 5 is in conflict with the other side of the first clamping member 2 and the second clamping member 3. The first moving mechanism 4 and the second moving mechanism 5 are installed on the workbench 1 by means of threads. When the screws are rotated at the same time, the first clamping member 2 and the second clamping member 3 will move on the workbench accordingly, thereby adjusting the test position of the diaphragm.

[0037] A conductive terminal 6 and a discharge terminal 7 are also provided on the insulating plate of the workbench 1. The conductive terminal 6 is grounded through a coupling plate. The discharge terminal 7 and the conductive terminal 6 are located on opposite sides of the diaphragm to be detected 10 between the first clamping member 2 and the second clamping member 3. One end of the discharge terminal 7 is vertically contacted and connected to the discharge end of the electrostatic generator 8. Preferably, the distance from the discharge terminal 7 to the diaphragm to be detected 10 is adjustable. Specifically, the discharge terminal 7 can be installed on the workbench 1 by threading; the conductive terminal 6 is connected to the tooling coupling plate 9 and then grounded.

[0038] The test method for diaphragm electrostatic discharge includes the following steps:

[0039] S1, placing the diaphragm 10 to be tested on an insulating plate and eliminating static electricity on the diaphragm 10 to be tested;

[0040] Specifically, firstly, cut the sample of the membrane 10 to be tested, and wear an anti-static wristband during the cutting process of the sample of the membrane 10 to be tested. Generally, the membrane 10 to be tested is 40mm*40mm;

[0041] Check the surface condition of the diaphragm 10 to ensure that the diaphragm 10 is intact. Specifically, check the surface condition of the diaphragm 10 by an optical microscope to ensure that the diaphragm is intact, and check the air permeability of the diaphragm by an air permeability tester, and keep records;

[0042] Performing static elimination treatment on the diaphragm 10 to be tested and placing the diaphragm 10 to be tested on an insulating plate;

[0043] S2, placing the conductive terminal 6 on one side of the diaphragm 10 to be detected, placing the discharge terminal 7 on the second side of the diaphragm 10 to be detected, the discharge terminal 7 is opposite to the conductive terminal 6, and the diaphragm 10 to be detected opposite to the conductive terminal 6 and the discharge terminal 7 is the detection area, and a first gap is formed between the diaphragm 10 to be detected and the conductive terminal 6, and a second gap is formed between the diaphragm 10 to be detected and the discharge terminal 7; specifically, the distance from the diaphragm 10 to be detected to the discharge terminal 7 is equal to the distance from the diaphragm 10 to be detected to the conductive terminal 6, both of which are 1mm or 2mm;

[0044] The outer diameter and material of the discharge terminal 7 and the conductive terminal 6 are the same, and in order to ensure a better electrostatic discharge test effect, the outer diameter of the end of the conductive terminal 6 opposite to the diaphragm to be detected 10 gradually increases from the end close to the diaphragm to be detected 10 to the end away from the diaphragm to be detected 10; the outer diameter of the end of the discharge terminal 7 opposite to the diaphragm to be detected 10 gradually increases from the end close to the diaphragm to be detected 10 to the end away from the diaphragm to be detected 10;

[0045] The end of the conductive terminal 6 opposite to the diaphragm to be detected 10 is conical, and the end of the discharge terminal 7 opposite to the detection diaphragm is conical. The tips of the conductive terminal 6 and the discharge terminal 7 are opposite to the diaphragm to be detected 10, thereby increasing the electrostatic discharge test effect;

[0046] S3, the conductive terminal 6 is grounded, the electrostatic generator 8 is connected to the discharge terminal 7 and applies static electricity to the discharge terminal to achieve an electrostatic discharge test on the area to be tested;

[0047] Specifically, the electrostatic generator 8 includes an electrostatic gun, and the electrostatic discharge conditions (such as ±6kV, ±7.5kV, ±8kV, etc.) are selected according to the material of the diaphragm 10 to be tested and the use environment, and the electrostatic discharge network (such as 150pf, 330Ω) is selected according to the test requirements. The discharge terminal 7 of the electrostatic gun is aligned with the discharge terminal 7 of the left tooling to perform an electrostatic discharge test on the diaphragm 10 to be tested;

[0048] The detection process also includes moving the diaphragm 10 to be detected relative to the discharge terminal 7 and the conductive terminal 6 to change the position. Specifically, the position of the area to be detected is manually changed by rotating the first moving mechanism 4 and the second moving mechanism 5.

[0049] After the test is completed, brush the diaphragm clamping plate with an electrostatic brush to eliminate static electricity; turn off the electrostatic generator 8;

[0050] S4, detecting the damage of the diaphragm 10 to be detected.

[0051] Place the diaphragm 10 to be tested under an optical microscope, observe the damage of the diaphragm 10 to be tested, including the damage and breakdown diameter and area, and measure the air permeability of the diaphragm 10 to be tested with an air permeability meter, and make a record. Use a scanning electron microscope to further magnify the point where the electrostatic discharge is applied to the diaphragm 10 to be tested, and observe the surface state of the diaphragm 10 to be tested;

[0052] Of course, those skilled in the art can also use a magnifying glass or other tools to observe the damage of the diaphragm 10 to be inspected, and an optical microscope has relatively higher accuracy.

[0053] In step S4 , the air permeability of the membrane 10 to be tested is also tested.

[0054] The air permeability of the diaphragm after the electrostatic discharge test can be used to judge the electrostatic discharge performance of the diaphragm from another perspective.

[0055] Specifically, the damage condition of the diaphragm in step S4 includes the damage diameter, the damage area, the breakdown diameter and the breakdown area.

[0056] Compared with the prior art diaphragm electrostatic discharge test which requires the diaphragm to be punctured before its performance can be judged, the present invention can judge the diaphragm electrostatic discharge performance without puncturing the diaphragm.

[0057] The advantages of this patent are:

[0058] (1) Currently, the industry does not conduct electrostatic discharge tests on diaphragms, and there is no relevant electrostatic discharge test method. This solution is the first application in the industry and has developed a method for electrostatic discharge testing of diaphragms.

[0059] (2) This plan describes in detail the cutting requirements for the diaphragm samples to be tested before testing, and other test requirements for the samples before testing, such as optical microscope inspection, recording the status of the diaphragm samples before testing, and using an air permeability tester to check the air permeability of the diaphragm; this plan also describes in detail the operating steps during the test and the optical inspection and air permeability inspection of the diaphragm samples after the test.

[0060] (3) This scheme simulates the discharge state of the diaphragm during actual processing and use, and can screen the electrostatic discharge performance of the diaphragm in the early stage, thereby improving the quality of the diaphragm and further improving the quality of the battery cell.

[0061] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for testing electrostatic discharge of a diaphragm, characterized in that: The steps include: S1. Place the diaphragm to be tested without static electricity on an insulating plate; S2, placing the conductive terminal on one side of the diaphragm to be detected, and placing the discharge terminal on the second side of the diaphragm to be detected, the discharge terminal is opposite to the conductive terminal, and the diaphragm to be detected opposite to the conductive terminal and the discharge terminal is the detection area; S3, the conductive terminal is grounded, the electrostatic generator is in contact with the discharge terminal and static electricity is applied to the discharge terminal, thereby realizing the electrostatic discharge test of the diaphragm in the test area; S4. Detect damage or breakdown of the diaphragm to be detected.

2. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: Step S1 also includes cutting the membrane sample to be tested, and wearing an anti-static wristband while cutting the membrane sample to be tested.

3. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: Before eliminating the static electricity of the diaphragm to be detected, step S1 also includes detecting the surface condition of the diaphragm to be detected to ensure that the diaphragm to be detected is intact.

4. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: In step S2, the outer diameter of the end of the conductive terminal opposite to the diaphragm to be detected gradually increases from the end close to the diaphragm to be detected to the end away from the diaphragm to be detected; and / or The outer diameter of the end of the discharge terminal opposite to the diaphragm to be detected gradually increases from the end close to the diaphragm to be detected to the end far away from the diaphragm to be detected.

5. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: Step S3 also includes adjusting the position of the diaphragm to be detected to change the area to be detected.

6. The method for testing electrostatic discharge of a diaphragm according to claim 5, characterized in that: In step S3, the conductive terminal is connected to the tooling coupling plate and then grounded.

7. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: In step S4, the damage of the diaphragm to be inspected is detected by an optical microscope.

8. The method for testing electrostatic discharge of a diaphragm according to claim 7, characterized in that: Step S1 also includes testing the air permeability of the membrane to be tested by using an air permeability tester; Step S4 also includes detecting the air permeability of the membrane to be detected.

9. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: The damage condition of the diaphragm in step S4 includes the damage diameter, the damage area, the breakdown diameter and the breakdown area.

10. The method for testing electrostatic discharge of a diaphragm according to claim 1, characterized in that: In step S2, the distance between the conductive terminal and the diaphragm to be detected is 1 mm-20 mm; and / or The distance from the discharge terminal to the diaphragm to be tested is 1mm-20mm.

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