Conductive particle coating method for dielectric strength testing

Abstract

This invention relates to production and testing technologies for cells, particularly to a conductive particle coating type dielectric withstand voltage test method. The method includes the steps of: assembling a cell awaiting measurement by pressing an electrode protective cover plate onto the electrodes in the insulating layer of the cell; moving the cell awaiting measurement into a metal groove; filling the space between the metal groove and the insulating layer of the cell awaiting measurement with conductive particles; connecting the ground terminal of the dielectric withstand voltage testing equipment to the cell awaiting measurement with a conductor; and connecting the high-voltage terminal of the dielectric withstand voltage testing equipment to the metal groove with a second conductor. Testing the cell awaiting measurement with the dielectric withstand voltage testing equipment allows the insulating coating layer of the cell awaiting measurement to be sufficiently coated with conductive particles, thus avoiding the formation of gaseous portions (bubbles or gas gaps) between the conductive medium and the insulating coating layer, preventing the concealment of defects such as insufficient insulation in the cell coating layer due to excessive impedance in the gaseous portion, and preventing cells that fail the insulation test from being released.

Description

Technical Field

[0001] The present invention relates to the technical field of cell production and detection, and particularly to a conductive particle coating type insulation withstand voltage test method.

Background Art

[0002] A battery module is assembled by connecting a large number of cells, which are independent small batteries, in series. Whether it is a cylindrical cell or a prismatic cell, insulation is required between cells and between a cell and a support plate. Moreover, it is necessary to ensure that the case of the cell always satisfies a certain insulation property. Otherwise, in case of leakage, the heat of the cell cannot be controlled, and an accident will occur. Therefore, when producing and assembling cells, it is necessary to measure the insulation performance of the cell case.

[0003] There are two common test methods for the insulation property of the coating layer on the cell case. The first is to measure the sampled locations. On the other hand, the second is to coat with conductive rubber as a conductive medium for measurement. In the former case, there is a risk that unqualified points may be missed. In the latter case, there is a problem of difficulty in firmly bonding the conductive rubber and the insulation coating layer. Repeated contact and collision occur between the cell and the conductive rubber. Also, if the quality of the conductive rubber itself is poor, a gas part (bubbles or gas gaps) will occur between the conductive medium and the insulation coating layer, and unqualified products with insufficient insulation of the cell coating layer due to the large impedance of the gas part may flow into the market.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a conductive particle coating type insulation withstand voltage test method for solving the problems mentioned in the background art.

Means for Solving the Problems

[0005] In order to solve the above problems of the invention, the conductive particle coating type insulation withstand voltage test method of the present invention is Step A involves pressing the electrode protection cover plate against the electrode in the insulating layer of the cell to assemble the cell awaiting measurement, Step B involves moving the cell awaiting measurement into the metal groove, Step C involves filling the space between the metal groove and the insulating layer of the cell awaiting measurement with conductive particles, Step D involves connecting the grounding terminal of the insulation withstand voltage testing equipment to the cell awaiting measurement using a wire, Step E involves connecting the high-voltage terminal of the insulation withstand voltage tester to the metal groove using a second conductor, Step F includes testing the cells awaiting measurement using an insulation withstand voltage testing device.

[0006] Preferably, before assembling the cell awaiting measurement by pressing the electrode protection cover plate in step A against the electrodes in the insulating layer of the cell, an elastic adhesive strip is attached beneath the electrode protection cover plate, and an electrode groove is created beneath the elastic adhesive strip.

[0007] Preferably, the electrode protective cover plate is pressed into place after the electrode is completely covered by the electrode groove.

[0008] Preferably, after moving the measurement waiting cell in step B into the metal groove, the positions of the measurement waiting cell and the metal groove are adjusted so that they are concentric.

[0009] Preferably, when conductive particles are filled between the metal groove and the insulating layer of the cell awaiting measurement in step C, the stability of the cell awaiting measurement within the metal groove is maintained, and the conductive particles are filled into the metal groove from bottom to top.

[0010] Preferably, when the conductive particles are filled into the metal groove from bottom to top, the height of the filled conductive particles is made higher than the tip of the insulating layer of the cell to charge the conductive particles.

[0011] Preferably, the conductive particles include one or more of tin, silver, gold, platinum, and stainless steel grid particles.

[0012] Preferably, the particle size of the conductive particles is 0.1 mm to 1 mm.

[0013] Preferably, when connecting the ground terminal of the insulation withstand voltage testing equipment and the cell awaiting measurement with the conductor in step D, the probe connected by the conductor is made to penetrate the electrode protective cover plate and the elastic adhesive strip in sequence, and the bottom end of the probe is made to contact the tip of the positive electrode of the cell awaiting measurement.

[0014] Preferably, when testing the cells awaiting measurement using the insulation withstand voltage testing equipment in step F, the measurement data from the insulation withstand voltage testing equipment is recorded, and the measurement data is compared with the logical reference data to determine whether the cells awaiting measurement have passed the test. [Effects of the Invention]

[0015] The beneficial effects of the present invention are as follows: The method according to the present invention allows the insulating coating layer of cells awaiting measurement to be sufficiently covered with conductive particles, thereby avoiding the formation of gaseous portions (bubbles or gas gaps) between the conductive medium and the insulating coating layer. This prevents defective products with insufficient insulation of the cell coating layer due to the large impedance of the gaseous portions from entering the market. [Brief explanation of the drawing]

[0016] [Figure 1] This is a flowchart of the process of the present invention. [Figure 2] This is a cross-sectional view of the metal groove of the present invention. [Modes for carrying out the invention]

[0017] The following describes preferred embodiments of the present invention with reference to the drawings. However, please understand that these preferred embodiments are merely for the purpose of explaining and understanding the present invention and do not limit it. [Examples]

[0018] As shown in Figures 1 and 2, the conductive particle coating type dielectric strength test method is as follows: Step A of assembling the measurement-waiting cell 3 by press-fitting the electrode protection cover plate 2 onto the electrode in the insulating layer of the cell 1 Step B of moving the measurement-waiting cell 3 into the metal groove 4 Step C of filling conductive particles between the metal groove 4 and the insulating layer of the measurement-waiting cell 3 Step D of connecting the grounding terminal 6 of the insulation withstand voltage testing device 5 and the measurement-waiting cell 3 with a conducting wire Step E of connecting the high-voltage terminal of the insulation withstand voltage testing device 5 and the metal groove 4 with a second conducting wire Step F of testing the measurement-waiting cell 3 with the insulation withstand voltage testing device 5, and it includes.

[0019] The principle and beneficial effects by the above means are as follows.

[0020] The manufacturer press-fits the electrode protection cover plate 2 onto the electrode in the insulating layer of the cell 1 to assemble the measurement-waiting cell 3. Next, the measurement-waiting cell 3 is placed in the metal groove 4, and conductive particles are filled between the metal groove 4 and the insulating layer of the measurement-waiting cell 3. After filling the conductive particles, the grounding terminal 6 of the insulation withstand voltage testing device 5 and the measurement-waiting cell 3 are connected with a conducting wire, and the high-voltage terminal of the insulation withstand voltage testing device 5 and the metal groove 4 are connected with a second conducting wire. However, the model number of the insulation withstand voltage testing device 5 is the TOS9300 model. Finally, the insulation withstand voltage testing device 5 is turned on to energize the measurement-waiting cell 3 and the metal groove 4 to detect the insulation of the insulation coating layer of the cell. Since the conductive particles can fully cover the insulation coating layer of the measurement-waiting cell 3, it is avoided that a gas part (bubbles or gas gaps) is formed between the conductive medium and the insulation coating layer. It is ensured that unqualified products with insufficient insulation of the cell coating layer due to the large impedance of the gas part will not flow into the market.

[0021] Before press-fitting the electrode protection cover plate 2 onto the electrode in the insulating layer of the cell 1 to assemble the measurement-waiting cell 3 in the step A, an elastic adhesive strip is attached under the electrode protection cover plate 2, and an electrode groove is opened under the elastic adhesive strip.

[0022] The principle and beneficial effects of the above-mentioned method are as follows: By attaching an elastic adhesive strip under the electrode protection cover plate 2, it is possible to prevent the electrode protection cover plate 2 from breaking down when measuring the dielectric strength of the cell 3 awaiting measurement, or to prevent a short circuit between electrodes due to the adhesion of a highly conductive substance to the electrode protection cover plate 2, which would otherwise result in the cell 3 awaiting measurement being discarded.

[0023] When the electrode is completely covered by the electrode groove, the electrode protective cover plate 2 is pressed into place.

[0024] The principle and beneficial effects of the above-mentioned method are as follows: By forming a circular groove in the elastic adhesive strip attached beneath the electrode protection cover plate 2, the insulating effect between the electrodes can be further enhanced by the circular groove. At the same time, covering the electrodes with the circular groove further enhances the effect of compression between the electrode protection cover plate 2 and the measurement waiting cell 3. When compressed, the electrodes are covered by the circular groove, so the electrode protection cover plate 2 can be securely attached to the tip of the measurement waiting cell 3. If it becomes necessary to move the measurement waiting cell 3, or if the measurement waiting cell 3 is subjected to external force, the electrode protection cover plate 2 will not detach from the measurement waiting cell 3. When the electrode protection cover plate 2 is compressed to the measurement waiting cell 3, the elastic adhesive strip attached beneath the electrode protection cover plate 2 can provide a good sealing effect to the tip of the measurement waiting cell 3, preventing conductive particles from entering the electrode surface during measurement. Because conductivity is imparted to the conductive particles themselves, the electrode protection cover plate 2 to which the elastic adhesive strip is attached can prevent conductive particles from entering the cell electrode surface and causing a short circuit in the cell.

[0025] Step B involves moving the measurement waiting cell 3 into the metal groove 4 and then adjusting the positions of the measurement waiting cell 3 and the metal groove 4 so that they are concentric.

[0026] The principle and beneficial effects of the above-mentioned method are as follows: When the positions of the cell 3 awaiting measurement and the metal groove 4 are adjusted to be concentric, conductive particles are immediately filled. Because the positions of the cell 3 awaiting measurement and the metal groove 4 are concentric, each side wall of the cell 3 awaiting measurement is maintained at an equal distance from one of the inner walls of the metal groove 4, ensuring that the lateral thickness of the filled conductive particles is uniform. Furthermore, this ensures that the electrical resistance between the cell 3 awaiting measurement and the metal groove 4 is uniform, avoiding the occurrence of voltage differences in the insulating coating layer located on the side walls of the cell 3 awaiting measurement when the cell 3 awaiting measurement is inspected. This prevents the detection of defects with insufficient insulation present in a part of the insulating coating layer where the voltage received is small, and furthermore, it increases the reliability when performing inspection using this method.

[0027] Step C, when filling conductive particles between the metal groove 4 and the insulating layer of the cell awaiting measurement 3, maintains the stability of the cell awaiting measurement 3 within the metal groove 4 and fills the metal groove 4 with conductive particles from bottom to top.

[0028] The principle and beneficial effects of the above-mentioned method are as follows: When conductive particles are added to the metal groove 4, the stability of the measurement waiting cell 3 within the metal groove 4 is maintained, ensuring that the measurement waiting cell 3 and the metal groove 4 are always concentric, guaranteeing that the thickness of the conductive particles located between the measurement waiting cell 3 and the metal groove 4 is uniform, and further guaranteeing that the voltage applied to the insulating coating layer located at the side wall position of the measurement waiting cell 3 is the same, thereby preventing measurement failures due to voltage differences and dielectric breakdown of the insulating coating layer caused by the presence of voltage differences.

[0029] When the conductive particles are filled into the metal groove 4 from bottom to top, it is preferable that the height of the filled conductive particles is higher than the leading edge of the insulating layer of cell 1.

[0030] The principle and beneficial effects of the above-mentioned method are as follows: If the height of the filled conductive particles is higher than the leading edge of the insulating layer of cell 1, the conductive particles can be filled, thereby ensuring that the insulating coating layer awaiting measurement in cell 3 is completely covered by the conductive particles, and preventing measurement leaks when the insulating withstand voltage testing device 5 is energized.

[0031] The conductive particles include one or more of tin, silver, gold, and platinum stainless steel grid particles.

[0032] The principle and beneficial effects of the above-mentioned method are as follows: The production process of cells may involve the use of large quantities of tin, silver, gold, and platinum materials, and some of these materials may leave behind polishing debris particles as residual particles during processing. Sorting and collecting these residual particles and using them as conductive particles can reduce initial production costs and minimize environmental pollution. Stainless steel grid may be used as the material for the conductive particles. Stainless steel grid has a low cost and a long lifespan. Depending on the situation, including one of tin, silver, gold, platinum, and stainless steel grid in the conductive particles will not only reduce the difficulty of collection and sorting, but also effectively reduce costs during testing and allow the conductive particles to be introduced into the actual testing process earlier.

[0033] The conductive particles have a particle size of 0.1 mm to 1 mm.

[0034] The principle and beneficial effects of the above-mentioned method are as follows: When repeatedly measuring dielectric strength, if the particle size of the conductive particles is in the range of 0.1 mm to 1 mm, it is possible to avoid the conductive particles scattering and turning into dust due to the movement of the measurement waiting cell 3 during the measurement process if the particle size is too small, and to avoid measurement failures in the insulating layer due to wide gaps between conductive particles if the particle size is too large. Furthermore, since conductive particles are solid materials with a particle size of 0.1 mm to 1 mm, when measuring cell 3, if it passes the inspection, it can be removed, given a simple cleaning, packaged, and immediately proceed to the next process. This increases inspection efficiency and makes it easier to clean the product.

[0035] As a result of long-term implementation, the following has been found: This method uses conductive particles with a particle size of 0.1 mm to 1 mm, and because the conductive particles used are made of tin, silver, gold, and platinum, the insulating coating layer of the cell 3 awaiting measurement does not experience abrasion when placed within or removed from the conductive particles. This improves the measurement quality of the cell 3 awaiting measurement.

[0036] When connecting the grounding terminal 6 of the insulation withstand voltage testing device 5 and the measurement waiting cell 3 with the conductor in step D, the probe connected by the conductor is made to sequentially penetrate the electrode protection cover plate 2 and the elastic adhesive strip, and the bottom end of the probe is made to contact the tip of the positive electrode of the measurement waiting cell 3.

[0037] The principle and beneficial effects of the above-mentioned method are as follows: The conductor equipped with the probe sequentially penetrates the electrode protection cover plate 2 and the elastic adhesive strip, and the bottom end of the probe comes into contact with the tip of the positive electrode of the cell awaiting measurement 3. Once the probe penetrates the electrode protection cover plate 2 and the elastic adhesive strip, the probe itself receives the frictional force between the elastic adhesive strip and the electrode protection cover plate 2, so the probe is stably placed on the electrode protection cover plate 2. At the same time, the probe and the positive electrode come into contact, and assuming the probe is stable, good contact between the probe and the positive electrode can be maintained, and by maintaining power supply to the insulation withstand voltage testing device 5, the voltage applied to the insulating coating layer of the cell awaiting measurement 3 becomes stable.

[0038] When the insulation withstand voltage testing device 5 in step F tests the cell 3 awaiting measurement, the measurement data from the insulation withstand voltage testing device 5 is recorded, and the measurement data is compared with the logical reference data to determine whether the cell 3 awaiting measurement has passed the test.

[0039] The principle and beneficial effects of the above-mentioned method are as follows: Before measuring the dielectric strength, logical reference data is obtained from the cell 3 awaiting measurement by performing tests and calculations using logic. When testing the cell 3 awaiting measurement using the dielectric strength testing device 5, the measurement data from the dielectric strength testing device 5 is recorded, and the measurement data is compared with the logical reference data to determine whether an insulation defect exists in the insulating coating layer of the cell 3 awaiting measurement. This improves the efficiency of the measurement.

[0040] Although the present invention has disclosed embodiments as described above, it is not limited to those described in the specification and embodiments, and the present invention can be applied to various fields. It will be easy for those skilled in the art to modify it to other forms. Therefore, the present invention is not limited to the specifics described in the specification and drawings, as long as it does not depart from the general concept limited by the scope equivalent to the claims. [Explanation of symbols]

[0041] 1 cell 2 Electrode protection cover plate 3 Cells awaiting measurement 4 metal groove 5. Insulation withstand voltage testing equipment 6 Ground terminal

Claims

1. Step A involves pressing the electrode protective cover plate (2) against the electrode in the insulating layer of the cell (1) to assemble the cell (3) awaiting measurement, Step B involves moving the cell (3) waiting to be measured into the metal groove (4), Step C involves filling conductive particles between the metal groove (4) and the insulating layer of the cell awaiting measurement (3), Step D involves connecting the grounding terminal (6) of the insulation withstand voltage testing device (5) and the measurement waiting cell (3) with a wire, Step E involves connecting the high-voltage terminal of the insulation withstand voltage testing device (5) to the metal groove (4) using a second conductor, A conductive particle-coated dielectric strength test method characterized by including step F, which involves testing a cell (3) awaiting measurement with an dielectric strength testing device (5).

2. The conductive particle coating type dielectric strength test method according to claim 1, characterized in that, before assembling the cell (3) awaiting measurement by pressing the electrode protection cover plate (2) in step A onto the electrode in the insulating layer of the cell (1), an elastic adhesive strip is attached under the electrode protection cover plate (2) and an electrode groove is made under the elastic adhesive strip.

3. The conductive particle coating type dielectric strength test method according to claim 2, characterized in that the electrode is completely covered by the electrode groove, and then the electrode protective cover plate (2) is pressed into place.

4. The conductive particle coating type dielectric strength test method according to claim 1, characterized in that, after moving the measurement waiting cell (3) in step B into the metal groove (4), the positions of the measurement waiting cell (3) and the metal groove (4) are adjusted to be concentric.

5. The conductive particle coating dielectric strength test method according to claim 1, characterized in that when conductive particles are filled between the metal groove (4) and the insulating layer of the cell awaiting measurement (3) in step C, the conductive particles are filled into the metal groove (4) from bottom to top while maintaining the stability of the cell awaiting measurement (3) within the metal groove (4).

6. The conductive particle coating type dielectric strength test method according to claim 5, characterized in that when the conductive particles are filled into the metal groove (4) from bottom to top, the height of the filled conductive particles is made higher than the tip of the insulating layer of the cell (1).

7. The conductive particle coating method for dielectric strength testing according to claim 6, characterized in that the conductive particles include one or more of tin, silver, gold, platinum, and stainless steel grid particles.

8. The conductive particle coating type dielectric strength test method according to claim 7, characterized in that the particle size of the conductive particles is 0.1 mm to 1 mm.

9. The conductive particle coated dielectric strength test method according to claim 1, characterized in that, when connecting the ground terminal (6) of the dielectric strength testing device (5) and the cell waiting to be measured (3) with the conductor in step D, the probe connected by the conductor is made to penetrate the electrode protective cover plate (2) and the elastic adhesive strip in order, and the bottom end of the probe is made to contact the tip of the positive electrode of the cell waiting to be measured (3).

10. The conductive particle coated insulation withstand voltage test method according to claim 1, characterized in that when testing the cell awaiting measurement (3) with the insulation withstand voltage testing device (5) in step F, the measurement data of the insulation withstand voltage testing device (5) is recorded, the measurement data is compared with the logical reference data, and it is determined whether or not the cell awaiting measurement (3) has passed the test.

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