Penetration test device including zero point adjustment device and penetration test method using the same

Abstract

The present invention relates to a penetration test device and a penetration test method using the same, which includes an upper pressure plate that presses the upper surface of a battery cell, a lower pressure plate that presses the lower surface of the battery cell, a through-hole formed in the upper pressure plate, a nail that penetrates the battery cell through the through-hole, and a zero point adjustment portion that protrudes outward from one outer periphery of the upper pressure plate, and which can accurately set the zero point that serves as a reference for the position where the nail is inserted.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0180150, filed December 12, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a penetration test device including a zero point adjustment device and a penetration test method using the same, and more particularly to a penetration test device including a zero point adjustment device for setting the zero point position of a nail during a penetration test of a pouch-type battery cell, and a penetration test method using the same. [Background technology]

[0003] Since an explosion of a lithium secondary battery can seriously affect the life of the user, safety evaluation tests against this are essential. Internal short circuits, overcharging, and over-discharging are the main causes that affect the safety of lithium secondary batteries. In particular, the penetration test, which is used to determine the effects of internal short circuits, is considered the most important evaluation test.

[0004] The penetration test involves using a nail, a needle-shaped metal conductor with a pointed bottom, to penetrate or push into a battery cell to a certain depth, inducing an internal short circuit in the battery, and observing whether a fire or explosion occurs. The insertion depth of the nail, which is inserted from the surface of the battery cell to the inside, is quantified as a certain value, and fire or explosion is confirmed when the nail is inserted to that depth. However, it is not easy to accurately measure the insertion depth of the nail through a penetration hole formed in the center of a plate-shaped member.

[0005] Patent Document 1 discloses an indentation test device that is configured to place a zero point assist jig having a reference height between the top surface of a battery and a nail, measure the position of the nail by moving the tip of the nail to the upper end of the zero point assist jig placed on the battery, compensate for the reference height to set a zero point value at the measured position, and position the tip of the nail on the surface of the battery using the zero point value during an indentation test.

[0006] In Patent Document 1, a battery is inserted into a test jig with a box structure that has a certain amount of space inside, and then fixed, and a compression test is performed. In this case, if a pouch-type battery cell is not compressed with a certain amount of force, the battery case and the electrode assembly may not be in close contact with each other. Therefore, there may be a difference between the depth at which the nail is inserted and the set depth.

[0007] In Patent Document 1, a prismatic battery inserted into a metal case does not have the same deformation in its external shape as a pouch-type battery, so the jig does not press the battery beyond a certain pressure. In Patent Document 1, the zero point assist jig used to determine the zero point position is a cylindrical object, and when used with a pouch-type battery, problems can occur if the laminate sheet of the pouch-type battery is not completely flat.

[0008] Patent Document 2 relates to an all-solid-state battery cell penetration test device, which includes a pressing part that presses a battery cell, a penetrating member that is inserted through a through hole formed in the pressing part and penetrates the battery cell, and an auxiliary pressing part that is disposed between the pressing part and the battery cell and transmits the pressure applied from the pressing part to the battery cell, and the auxiliary pressing part is disposed between the through hole and the battery cell in a form that blocks the through hole.

[0009] In Patent Document 2, the auxiliary pressing portion blocks the through hole of the pressing portion, making it difficult for the penetrating member to be inserted into the battery cell, and it is difficult to use it for a penetration test to cause an internal short circuit.

[0010] The voltage measurement in Patent Document 2 is different from the measurement of the exact position of the zero point performed in the present invention, and is a measurement of the voltage between the positive terminal of the battery undergoing the penetration test and the nail, which is intended to grasp the characteristics of the penetration stage.

[0011] FIG. 1 shows a perspective view of a conventional penetration test device for artificially inducing an internal short circuit.

[0012] 1, the penetration testing device includes an upper pressure plate 110 disposed on the upper surface of a battery cell 10, a lower pressure plate 210 disposed on the lower surface of the battery cell 10, and a nail 300 that penetrates the battery cell 10. The battery cell 10 is fixed in place by being pressed with a predetermined pressure by the upper pressure plate 110 and the lower pressure plate 210, and a through-hole 130 is formed in the center of the upper pressure plate 110 for the nail 300 to pass through. An insulating film 111 is attached to the lower surface of the upper pressure plate 110 and the upper surface of the lower pressure plate 210 to prevent short-circuiting of the battery cell 10.

[0013] Because the nail 300 is inserted into the through-hole 130, the structure makes it difficult for the worker to confirm the zero point, which is the position where the nail 300 contacts the surface of the battery cell 10 and serves as the reference for insertion depth.

[0014] To solve this problem, a method was used in which a plastic hexahedron 20 having a thickness corresponding to or thinner than the thickness of the battery cell 10 was inserted between an upper pressure plate 110 and a lower pressure plate 210, and the nail 300 was brought into contact with the upper surface of the plastic hexahedron 20 to set the zero point. Since the surface of the plastic hexahedron 20 is not flat, the zero point is set at the position where the nail 300 is judged to have come into contact with the surface of the plastic hexahedron 20, depending on the operator's eyes and senses, and the zero point reference may vary depending on the operator.

[0015] The upper pressure plate 110 has an insulating film 111 attached to its lower surface, but if the insulating film 111 is not attached up to the position where the plastic hexahedron 20 is interposed, the height of the plastic hexahedron 20 will not take into account the thickness of the insulating film 111, resulting in a deviation equal to the thickness of the insulating film 111.

[0016] For example, a test can be performed on a battery cell by penetrating 2.2 mm from the surface of the battery cell, or a test can be performed on an electrode assembly in a battery cell by penetrating three to five sets of mono-cells. In this case, if a conventional method or the method described in Patent Document 1 is used, the plastic hexahedron 20 may not be properly aligned, errors due to the thickness of the insulating film 111 may not be taken into account, or an accurate test may not be possible due to the uneven surface of the pouch-type battery cell case. When conventional penetration testing devices are used in the field, there is a problem that the quality of the product varies depending on the person actually performing the test.

[0017] As such, there is a need for a technology that can perform a penetration test with the battery cell tightly attached so that no space is formed between the battery case and the electrode assembly, and that can set the zero point by inserting the nail to a predetermined nail insertion depth to improve the accuracy and reliability of the penetration test. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] Korean Patent Publication No. 10-2023-0006265 [Patent Document 2] Korean Patent Publication No. 10-2023-0061044 Summary of the Invention [Problem to be solved by the invention]

[0019] The present invention has been made to solve the above problems, and aims to provide a penetration test device equipped with a zero point adjustment device that can accurately set a zero point, which is a reference for nail insertion depth, regardless of the operator, and perform the test under conditions that meet the penetration test criteria, thereby increasing the reliability of the results, and a penetration test method using the same. [Means for solving the problem]

[0020] To achieve this object, the penetration test device according to the present invention may include an upper pressure plate that presses the upper surface of a battery cell, a lower pressure plate that presses the lower surface of the battery cell, a through-hole provided in the upper pressure plate, a nail that penetrates the battery cell through the through-hole, and a zero point adjustment portion that protrudes outward from an outer periphery on one side of the upper pressure plate.

[0021] The device may further include a resistance measuring unit for checking whether the nail is in contact with the zero point adjusting unit.

[0022] The resistance measuring unit may include a first terminal and a second terminal, the first terminal being connected to the nail and the second terminal being coupled to the zero point adjustment unit.

[0023] The top surface of the zero point adjustment unit may be flush with the bottom surface of the top pressure plate.

[0024] An insulating film may be attached to the lower surface of the upper pressure plate.

[0025] The first region of the zero point adjustment unit may be attached such that an upper surface thereof overlaps a lower surface of the upper pressure plate, and the second region of the zero point adjustment unit may be positioned to protrude outward from an outer circumferential surface of the upper pressure plate.

[0026] The first region of the zero point adjustment unit may be attached to the lower surface of the upper pressure plate via an adhesive member.

[0027] The battery pack may further include a pressure adjusting means for adjusting the magnitude of the pressure applied by the upper and lower pressure plates to the battery cell.

[0028] The penetration test method using the penetration test device can include a first step of fixing a battery cell between an upper pressure plate and a lower pressure plate, a second step of contacting a nail with a zero point adjustment unit to set the zero point, and a third step of penetrating the battery cell with the nail.

[0029] The first step may include a step of adjusting the positions of the upper and lower pressure plates so that the upper and lower pressure plates are in close contact with the battery cells.

[0030] The second step may include a step of bringing the nail into contact with an upper surface of the zero point adjustment unit and setting the zero point at a position where the resistance of a resistance measuring unit connected to each of the nail and the zero point adjustment unit becomes zero.

[0031] The process of bringing the nail into contact with the top surface of the zero point adjustment part may be performed twice in succession.

[0032] The second step may include a step of moving the nail close to an upper portion of the zero point adjustment portion at a speed of 0.1 mm / s until the nail contacts the zero point adjustment portion.

[0033] The third step may be performed until the nail insertion depth reaches a set value.

[0034] Furthermore, the present invention can also be provided in the form of various combinations of means for solving the above problems. [Effects of the Invention]

[0035] As described above, the penetration test device according to the present invention includes an upper pressure plate and a lower pressure plate for pressing on the battery cells, which makes it possible to make the height of the battery cells uniform and to ensure that the upper surface of the electrode assembly and the battery case are in close contact with each other in the pouch-type battery cells.

[0036] In addition, since the zero point adjustment unit is provided in consideration of the thickness of the insulating film attached to the upper pressure plate, the zero point, which is the reference for the insertion depth of the nail starting from the surface of the battery cell, can be accurately set. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a perspective view of a conventional penetration test device. [Figure 2]1 is a perspective view of a penetration testing device according to the present invention; [Figure 3] FIG. 3 is a vertical cross-sectional view taken along line AA' in FIG. 2. [Figure 4] FIG. 4 is a vertical cross-sectional view of a state in which a pressing force adjusting means is added to FIG. 3. [Figure 5] 3 is a plan view of the upper pressure plate and the lower pressure plate of FIG. 2. FIG. [Figure 6] 10 is a graph showing the relationship between the pressing force and the insertion depth of the nail during a penetration test according to an embodiment. [Figure 7] 10 is a graph showing the relationship between the pressing force and the insertion depth of the nail during a penetration test according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. In describing the operation principle of the embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0039] Throughout the drawings, the same reference numerals are used for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0040] Descriptions that limit or specify additional elements are applicable to all inventions and are not limited to a particular invention unless otherwise limited.

[0041] Throughout the description and claims of this invention, the singular includes the plural unless otherwise stated.

[0042] Throughout the description and claims, "or" includes "and" unless otherwise stated. Thus, "comprising A or B" means the three cases of including A, including B, or including both A and B.

[0043] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0044] FIG. 2 is a perspective view of a penetration testing device according to the present invention, and FIG. 3 is a vertical cross-sectional view taken along line A-A' in FIG.

[0045] 2 and 3, the penetration test device according to the present invention includes an upper pressure plate 110 that presses the upper surface of the battery cell 10, a lower pressure plate 210 that presses the lower surface of the battery cell 10, a through hole 130 provided in the upper pressure plate 110, a nail 300 that penetrates the battery cell 10 through the through hole 130, and a zero point adjustment part 120 that protrudes outward from one outer periphery of the upper pressure plate 110.

[0046] The battery cell 10 may include a prismatic battery cell or a pouch-type battery cell, and FIG. 2 shows a pouch-type battery cell being fixed by being pressed by an upper pressure plate 110 and a lower pressure plate 210. The pouch-type battery cell may be a bidirectional battery cell in which two electrode leads 11 protrude in opposite directions, or a unidirectional battery cell in which two electrode leads protrude in the same direction. The drawing shows, as a non-limiting example, a bidirectional battery cell in which two electrode leads 11 protrude in opposite directions.

[0047] The present invention can perform a penetration test by setting a depth to which the nail 300 is pressed from the surface of the battery cell 10 into the inside of the battery cell 10 in advance, and checking whether the battery cell ignites or explodes when the nail presses the battery cell to the preset depth.

[0048] Generally, a separate device is used to push the nail in. This device allows the nail's pushing speed and insertion depth to be set and controlled. For example, if the nail is set to penetrate 2.2 mm into the battery cell, the surface of the battery cell is set as the zero point, and the nail is pushed in the preset 2.2 mm, the nail must actually penetrate 2.2 mm into the battery cell.

[0049] If the pressing force of the upper and lower pressure plates pressing against the battery cell is weak, the penetration test may be performed in a bulging state of the battery cell, which may result in the nail not being able to press against the electrode assembly to the preset insertion depth.

[0050] Therefore, the present invention provides a zero point adjustment part 120 that protrudes outward from one side of the outer periphery of the upper pressure plate 110, and sets the zero point by checking whether the nail 300 and the zero point adjustment part 120 are in contact with each other.

[0051] The nail 300 and the zero point adjustment unit 120 are made of conductive material that allows electricity to pass through them, and when they come into contact with each other, electricity passes through them. Therefore, a resistance measuring unit 400 is included to check whether the nail 300 and the zero point adjustment unit 120 are in contact with each other.

[0052] The resistance measuring unit 400 includes a first terminal 401 and a second terminal 402. The first terminal 401 is connected to the nail 300, and the second terminal 402 is connected to the zero point adjustment unit 120. When the nail 300 is brought into contact with the zero point adjustment unit 120, the resistance measured by the resistance measuring unit 400 is within 5 ohms and is close to 0 ohms. That is, when the nail 300 is not in contact with the zero point adjustment unit 120, the resistance measured by the resistance measuring unit 400 is not measured, or is essentially infinite. However, at the moment when the nail 300 and the zero point adjustment unit 120 come into contact, current flows between the nail 300 and the zero point adjustment unit 120, and the resistance measured by the resistance measuring unit 400 is close to 0 ohms.

[0053] In this specification, it is explained that the resistance value measured when the nail and the zero point adjustment part are in contact is 0 Ohm.

[0054] The zero point adjustment unit 120 is a means for setting the state in which the nail 300 contacts the surface of the battery cell 10 as the zero point, and the top surface 122 of the zero point adjustment unit with which the nail 300 contacts must be located on the same plane as the bottom surface of the top pressure plate 110. Since the bottom surface of the top pressure plate 110 is considered to be located on the same plane as the top surface 12 of the battery cell, the top surface 122 of the zero point adjustment unit can be considered to be located on the same plane as the top surface 12 of the battery cell.

[0055] Generally, the lower surface of the upper pressure plate 110 and the upper surface of the lower pressure plate 210 are in direct contact with the battery cells 10, and therefore, for safety reasons, insulating films 111, 211 are attached to them. The insulating films 111, 211 may be configured such that an adhesive layer is provided on one surface of an insulating layer made of an insulating material, and the adhesive layer is attached to the lower surface of the upper pressure plate and the upper surface of the lower pressure plate, respectively.

[0056] The insulating material is not particularly limited as long as it is a known insulating material. The insulating film 111, 211 may be provided on the entire surface facing the battery cell 10, but since the zero point adjustment part 120 is configured to protrude from the outer periphery of one side of the upper pressure plate 110, no insulating film is attached to the protruding part of the zero point adjustment part 120.

[0057] The zero point adjustment part 120 is configured to protrude from one side outer periphery of the upper pressure plate 110 so that contact of the nail 300 can be easily confirmed with the naked eye from the outside. Therefore, the first region 120a of the zero point adjustment part 120 is attached so that its upper surface overlaps the lower surface of the upper pressure plate 110, and the second region 120b of the zero point adjustment part 120 is configured to protrude outward from the outer periphery of the upper pressure plate 110.

[0058] The first region 120a of the zero point adjustment unit 120 is attached to the lower surface of the upper pressure plate 110 via an adhesive member 121, which can be an adhesive or a double-sided adhesive tape.

[0059] The position of the top surface 122 of the zero point adjustment unit must be adjusted by the thickness of the insulating film 111 attached to the bottom surface of the top pressure plate 110. Preferably, an adhesive member 121 is attached between the zero point adjustment unit 120 and the top pressure plate 110, and the thickness of the adhesive member 121 is set to be the same as or similar to the thickness of the insulating film 111. However, there may be a difference in the thickness of the adhesive member 121 and the insulating film 111, measured on the order of micrometers. While there may be a difference because the insulating film 111 has an adhesive layer only on one side, while the adhesive member 121 has adhesive layers on both sides, this level of error is unlikely to have a significant effect on the results of the penetration test. For more precise measurements, the insulating film and adhesive member may be selected taking into account the thickness of the adhesive layer.

[0060] In this way, even when the insulating film 111 is attached to the underside of the upper pressure plate 110, the upper surface 122 of the zero point adjustment unit is connected to the upper pressure plate 110 via the adhesive member 121, and the thickness of the insulating film 111 is offset and corrected by the thickness of the adhesive member 121, so that the upper surface 122 of the zero point adjustment unit is positioned flush with the underside of the insulating film 111 attached to the underside of the upper pressure plate 110. Therefore, the upper surface 122 of the zero point adjustment unit is positioned flush with the upper surface 12 of the battery cell.

[0061] Figure 4 is a vertical cross-sectional view of Figure 3 with a pressure adjustment means added, and Figure 5 is a plan view of the upper pressure plate and the lower pressure plate of Figure 2. In Figure 5, the enlarged view is an enlarged view of the upper pressure plate 110, and below that is a plan view of the lower pressure plate 210.

[0062] 4 and 5 together with FIGS. 2 and 3, a pressing force adjusting means is provided that can adjust the magnitude of the force with which the upper pressing plate 110 and the lower pressing plate 210 press the battery cell 10.

[0063] 2 and 5, six first fastening holes 140 are formed in the upper pressure plate 110, and six second fastening holes 240 are formed in the lower pressure plate 210. Fig. 2 shows a configuration in which a bolt 301 is inserted so as to pass through one of the first fastening holes 140 and the second fastening hole 240, and the bolt 301 is fixed using a nut 302.

[0064] FIG. 2 is for illustrative purposes only; all first fastening ports 140 and all second fastening ports 240 must be fastened using bolts 301 and nuts 302, and the spacing between the first fastening ports 140 and the second fastening ports 240 must be the same at all six positions to ensure uniform bolt fastening pressure.

[0065] The pressing force adjusting means according to the present invention is not limited to the combination of the bolt 301 and the nut 302, but may include a configuration in which a pressing cylinder is attached to each of the upper pressing plate and the lower pressing plate, or a configuration in which separate pressing members are attached to press the upper pressing plate and the lower pressing plate.

[0066] However, if the force applied to the battery cell is too strong or too weak, the penetration test may not match the preset nail insertion depth, so it may be necessary to search for the optimal pressing state by pressing the battery cell multiple times. For example, the battery cell is properly pressed when its top surface is flat and not bulging. Considering that the pressure applied to fix the battery cell in a jig and perform a cycle test is usually about 4 kgf, this may be a state where the battery cell is pressed with a force greater than this. Specifically, the force applied to press the battery cell may be 5 kgf to 50 kgf.

[0067] If the battery cell is pressed with a force less than 5 kgf, the battery cell may become overly expanded, and even if the nail is pressed in to the preset depth, the actual penetration depth of the battery cell will be shallower than that. When the nail is pressed in, the pressure on the nail can be measured at the same time, and if it is confirmed that the pressure on the nail does not reach the reference pressure, it can be determined that the battery cell is being pressed with a force less than 5 kgf.

[0068] The clamping pressure may be determined differently for each battery cell, and is determined based on the electrochemical criteria of the battery cell, so a qualitative, rather than quantitative, criterion must be presented.

[0069] The penetration test method using the penetration test device according to the present invention includes a first step of fixing the battery cell 10 between the upper pressure plate 110 and the lower pressure plate 210, a second step of contacting the nail 300 with the zero point adjustment unit 120 to set the zero point, and a third step of penetrating the battery cell 10 with the nail 300.

[0070] The first step may involve adjusting the positions of the upper pressure plate 110 and the lower pressure plate 210 so that the upper pressure plate 110 and the lower pressure plate 210 are in close contact with the battery cell 10 .

[0071] The second step may involve contacting the nail 300 with the top surface of the zero point adjustment unit 120 and setting the zero point to a position where the resistance of the resistance measuring unit 400 connected to each of the nail 300 and the zero point adjustment unit 120 is 0 Ohm.

[0072] In the process of setting the zero point, the speed at which the nail 300 moves downward toward the zero point adjustment unit 120 is important in order to accurately measure the moment when the nail 300 comes into contact with the zero point adjustment unit 120 and to prevent damage to the tip of the nail 300. For example, when the nail 300 moves close to a position where it does not come into contact with the zero point adjustment unit 120, it moves downward at a speed of 5 mm / s, and when the nail 300 approaches the zero point adjustment unit 120, it moves downward at a speed of 0.1 mm / s until the nail 300 comes into contact with the zero point adjustment unit 120, while checking the resistance measurement unit.

[0073] Here, in order to more accurately confirm the zero point position, the process of bringing the nail 300 into contact with the top surface of the zero point adjustment unit 120 can be performed twice in succession.

[0074] The third step can be performed until the insertion depth of the nail 300 reaches a set value.

[0075] In this way, the present invention sets the zero point, which is the surface position of the battery cell, using the zero point adjustment unit while pressing the battery cell with an appropriate force, so that a penetration test can be performed accurately for the preset insertion depth. Since the nail 300 is equipped with a means for measuring its own position, the relative movement displacement can be determined after setting the zero point. In addition, the value at which the zero point is set can be determined from the value of the measurement unit equipped in the nail 300 itself.

[0076] That is, the set value of the zero point is confirmed through a measuring unit provided in the nail 300 itself. Then, the nail 300 is moved upward to separate from the zero point adjustment unit 120, and then moved horizontally to the position of the through hole 130. The nail 300 is moved downward from the position of the through hole 130 to the previously confirmed set value of the zero point. Here, the previously confirmed set value of the zero point can be confirmed through a measuring unit provided in the nail 300 itself. Then, the actual penetration test is performed.

[0077] Below, in order to investigate whether the force with which the upper and lower pressure plates press the battery cells is too weak or appropriate has any effect on the penetration test of the battery cells, we will explain the case where the pressing force is weak as a comparative example and the case where the pressing force is appropriate as an example.

[0078] The appropriate magnitude of the pressing force is determined by the electrochemical standards of the battery cell, and in the examples of this specification, 5kgf to 50kgf is considered to be the appropriate magnitude, with the comparative example being a pressing force of 4kgf and the example being a pressing force of 20kgf.

[0079] <Example> A penetration testing device as shown in Figure 2 was prepared, a pouch-shaped battery cell was placed between an upper pressure plate and a lower pressure plate, the pressure applied to the pouch-shaped battery cell was set to 20 kgf, and the pouch-shaped battery cell was pressed by the upper pressure plate and the lower pressure plate.

[0080] The zero point is set on the outer surface of the pouch-type battery cell by touching the nail to the zero point adjustment part.

[0081] The nail was placed at the same position as the zero point through the through hole in the upper pressure plate, and the force with which the nail pressed against the pouch-type battery cell was measured while the nail was pressed so that it penetrated 2.2 mm from the zero point into the pouch-type battery cell.

[0082] FIG. 6 is a graph showing the measurement of the pressing force as a function of the nail insertion depth during the penetration test according to the embodiment.

[0083] <Comparative Example> A penetration test was carried out in the same manner as in the previous example, except that the force applied by the upper and lower pressure plates to press the pouch-type battery cells was 4 kgf.

[0084] FIG. 7 is a graph showing the measurement of the pressing force as a function of the nail insertion depth during the penetration test according to the comparative example.

[0085] 6 and 7, the horizontal axis represents the distance between the nail and the pouch-type battery cell. If the zero point, which is the surface of the pouch-type battery cell, is set to 0.0, then a minus sign (-) indicates the point before the nail comes into contact with the pouch-type battery cell. As the value increases from 0.0, the nail penetrates deeper into the pouch-type battery cell. The vertical axis represents the pressure applied by the nail to the pouch-type battery cell.

[0086] 6 shows that the pressure gradually increases from the 0.18 mm point onward, indicating that the nail penetrated the electrode assembly of the pouch-type battery cell up to the preset nail insertion depth of 2.2 mm. Therefore, it can be confirmed that the penetration test was conducted in this example with the upper and lower pressure plates sufficiently pressing the pouch-type battery cell.

[0087] The graph in Figure 7 shows a case where the pressure applied by the upper and lower pressure plates to the pouch-type battery cell is weak, and the nail pressure does not increase from a nail insertion depth of 0.0 mm to 1.0 mm, but the pressure increases from the 1.0 mm point onwards. In other words, the electrode assembly of the pouch-type battery cell was not penetrated from 0.0 mm to 1.0 mm.

[0088] Therefore, only when a penetration test is conducted in a state where the pouch-type battery cell is fully pressed by the upper and lower pressure plates so that the battery case does not expand, can the nail be considered to have been inserted to the predetermined nail insertion depth, ensuring the reliability of the safety evaluation of the pouch-type battery cell.

[0089] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0090] 10 battery cells 11 Electrode Lead 12 Top of the battery cell 20 plastic hexahedrons 110 Upper pressure plate 111, 211 Insulation film 120 Zero point adjustment section 120a 1st area 120b 2nd area 121 Adhesive material 122 Top surface of zero point adjustment section 130 Through hole 140 First fastening port 210 Lower pressure plate 240 Second fastening port 300 Nehru 301 volts 302 Nut 400 Resistance measurement unit 401 1st terminal 402 2nd terminal

Claims

1. an upper surface pressing plate that presses the upper surface of the battery cell; a lower surface pressing plate that presses the lower surface of the battery cell; a through hole provided in the upper pressure plate; a nail that penetrates the battery cell through the through hole; a zero point adjustment portion protruding outward from one side outer periphery of the upper pressure plate; 1. A penetration testing device comprising:

2. The penetration test device according to claim 1 , further comprising a resistance measuring unit for checking whether or not the nail is in contact with the zero point adjusting unit.

3. the resistance measuring unit includes a first terminal and a second terminal, The penetration test device according to claim 2 , wherein the first terminal is connected to the nail, and the second terminal is coupled to the zero point adjustment portion.

4. The penetration test device according to claim 1 , wherein an upper surface of the zero point adjustment portion is positioned on the same plane as a lower surface of the upper surface pressure plate.

5. 2. The penetration test device according to claim 1, wherein an insulating film is attached to the lower surface of said upper pressure plate.

6. 2. The penetration test device of claim 1, wherein the first region of the zero point adjustment portion is attached so that its upper surface overlaps the lower surface of the upper pressure plate, and the second region of the zero point adjustment portion is positioned so that it protrudes outward from the outer peripheral surface of the upper pressure plate.

7. 7. The penetration test device according to claim 6, wherein the first region of the zero point adjustment portion is attached to the lower surface of the upper surface pressure plate via an adhesive member.

8. The penetration test device according to any one of claims 1 to 7, further comprising a pressing force adjustment means capable of adjusting the magnitude of the force with which the upper pressure plate and the lower pressure plate press against the battery cell.

9. A penetration test method using the penetration test device according to claim 1, a first step of fixing the battery cell between an upper pressure plate and a lower pressure plate; a second step of contacting the nail with the zero adjustment portion to set the zero point; a third step of penetrating the battery cell with the nail; A penetration test method, including:

10. The penetration test method of claim 9 , wherein the first step includes adjusting the positions of the upper and lower pressure plates so that the upper and lower pressure plates are in close contact with the battery cell.

11. 10. The penetration test method of claim 9, wherein the second step comprises bringing the nail into contact with an upper surface of the zero point adjustment unit to set a position where a resistance of a resistance measuring unit connected to each of the nail and the zero point adjustment unit becomes zero as the zero point.

12. The penetration test method according to claim 11, wherein the step of bringing the nail into contact with the top surface of the zero point adjustment portion is performed twice consecutively.

13. 12. The penetration test method according to claim 11, wherein the second step includes a step of moving the nail close to an upper portion of the zero point adjustment portion at a speed of 0.1 mm / s until the nail comes into contact with the zero point adjustment portion.

14. The penetration test method according to claim 9, wherein the third step is performed until the insertion depth of the nail reaches a set value.

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