Battery cell side penetration test device and battery cell penetration test method using the same

Abstract

The present invention relates to a penetration testing device that includes a penetration portion having a needle-shaped conductor having a sharp needle shape, a guide portion that pushes the penetration portion so that the needle-shaped conductor pierces the side of a battery cell, and a holder that houses the penetration portion, and when the guide portion pushes the penetration portion, the needle-shaped conductor of the penetration portion penetrates the side of a battery cell, and a penetration testing method for a battery cell using the same.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0153612 dated November 10, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery cell side penetration test device and a battery cell penetration test method using the same, particularly to a battery cell side penetration test device for performing safety evaluation under harsher conditions than a penetration test that drills a hole in the bottom of a battery cell, and a battery cell penetration test method using the same. [Background technology]

[0003] 2. Description of the Related Art Rechargeable and dischargeable secondary batteries are used as energy sources for mobile devices, and more recently, they are also used as energy sources for devices that require large capacity and high output, such as electric vehicles.

[0004] In this way, in order to manufacture secondary batteries capable of large capacity and high output, the size of the battery pack also increases. However, due to the characteristics of secondary batteries, in the event of a fire, the fire cannot be extinguished until it is completely burned, it is important to have a structure to prevent fire in order to ensure safety.

[0005] For example, when an external impact or a sharp electrically conductive material penetrates the case of a secondary battery, the electrode plates of the electrode assembly having different polarities may be electrically connected through the electrically conductive material to form a short circuit. If a large short circuit current flows between the electrode plates, the temperature of the electrode plates increases, and the temperature of the electrolyte increases. The high temperature electrolyte causes a decomposition reaction to proceed quickly, generating a large amount of gas. Since the decomposition reaction of the electrolyte is an exothermic reaction, the temperature of the secondary battery increases rapidly locally around the point of penetration, which may cause the secondary battery to ignite and undergo thermal runaway.

[0006] Therefore, a battery cell penetration test is conducted at the development stage before the commercialization of secondary batteries to verify safety against penetration.

[0007] Generally, a battery cell penetration test is performed by penetrating a secondary battery with a needle-shaped conductor to intentionally cause a short circuit inside the secondary battery, and then measuring the temperature and voltage changes of the secondary battery and checking with the naked eye for the presence or absence of fire.

[0008] In this regard, FIG. 1 is a vertical cross-sectional view of a portion of a battery module illustrating a conventional battery cell penetration test.

[0009] 1, a plurality of cylindrical battery cells 100 are closely arranged and mounted inside a module case 200. The cylindrical battery cells have a structure that is vented toward the cap assembly, and a penetration test for the cylindrical battery cells is performed by drilling holes in the bottom 110 of the battery cells with a penetration test device.

[0010] In this manner, when the penetration test device pierces the bottom 110 of the battery cell, a flame is ejected onto the top 120 of the battery cell, making it difficult for the flame to spread to adjacent battery cells or cause a chain reaction of fire.

[0011] Meanwhile, in order to raise the safety standards of secondary batteries, it is necessary to carry out penetration tests of battery cells under more severe conditions. For example, when a hole is drilled on the side of a cylindrical battery cell, the explosive force may be transmitted to the battery cells adjacent to the punctured battery cell.

[0012] However, while the penetration testing device shown in FIG. 1 can either perforate the bottom of a cylindrical battery cell or perforate the side of a cylindrical battery cell that is not assembled into a battery module, it is difficult to perforate the side of a cylindrical battery cell that is assembled into a battery module.

[0013] Patent Document 1 relates to a nail for testing penetration of secondary batteries and a penetration test device for secondary batteries using the same, and discloses a method in which a pouch-type battery cell is placed on a stationary table and the nail is moved in a direction perpendicular to the rectangular plane of the pouch-type battery cell to push the secondary battery in. In other words, Patent Document 1 does not disclose a penetration test device that can penetrate the side surface of a cylindrical battery cell in a state in which the battery cells are assembled into a battery module.

[0014] Therefore, in order to manufacture secondary batteries with improved safety, it is necessary to develop a penetration test device that can perform a penetration test on a battery cell under harsh conditions and can penetrate the side of a cylindrical battery cell in a state where it is assembled into a battery module. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Korean Patent No. 1764299 Summary of the Invention [Problem to be solved by the invention]

[0016] The present invention has been made to solve the above problems, and aims to provide a battery cell side penetration test device that can check whether a flame will spread to adjacent battery cells and cause a chain ignition when evaluating the safety of battery cells that make up a battery module, and a battery cell penetration test method using the same. [Means for solving the problem]

[0017] To achieve this objective, the penetration testing device according to the present invention includes a penetration portion having a needle-shaped conductor having a sharp needle shape, a guide portion that pushes the penetration portion so that the needle-shaped conductor pierces the side of a battery cell, and a holder that houses the penetration portion internally, and can have a structure in which when the guide portion pushes the penetration portion, the needle-shaped conductor of the penetration portion penetrates the side of a battery cell.

[0018] The guide portion may push the through portion while moving into the holder.

[0019] A horizontal bar having the same length as the inner diameter of the holder is positioned inside the holder, and when the guide part presses the through-hole, the through-hole can rotate around the horizontal bar as a rotation axis.

[0020] An opening is formed in the holder, and when the through portion is pushed by the guide portion, the needle-shaped conductor of the through portion passes through the opening, and the outer end of the needle-shaped conductor that has passed through the opening can protrude from the surface of the holder.

[0021] The guide portion includes a front portion and a rear portion extending downward, a space is formed between the front portion and the rear portion, and the through portion can be inserted into the space when the guide portion is moved into the holder.

[0022] The holder may have a cylindrical structure, and an outer surface of the front part and an outer surface of the rear part of the guide part may have a curved surface corresponding to an inner cylindrical surface of the holder.

[0023] The penetrating portion includes a first surface to which a needle-like conductor is attached, and the first surface can have the form of a cut surface inclined with respect to an imaginary central axis of the penetrating portion.

[0024] An upper portion of the through-hole may be in close contact with an inner surface of the space in a thickness direction.

[0025] The inner surface of the rear portion has a planar shape, and an outer surface opposite to the first surface of the through-hole may include a planar portion that is in close contact parallel to the inner surface of the rear portion when the guide portion moves into the holder.

[0026] The present invention provides a penetration test method for a battery cell using the penetration test device, which includes the steps of: preparing a battery cell stack including a plurality of battery cells; removing one battery cell constituting the battery cell stack, and inserting the penetration test device into a portion from which the battery cell was removed; inserting a guide part of the penetration test device into a holder; and being pressed by the guide part so that a needle-shaped conductor of the penetration part penetrates a side surface of the battery cell.

[0027] The battery cells can include cylindrical battery cells, pouch battery cells, and prismatic battery cells.

[0028] The end of the needle-shaped conductor of the penetration test device can be arranged to face a side surface of the battery cell.

[0029] Moreover, the present invention can also be provided in the form of a combination of various means for solving the above problems. Effect of the Invention

[0030] As described above, the battery cell side penetration testing device according to the present invention is capable of perforating the side surface of a battery cell in a state where the battery cell is mounted in a battery module case.

[0031] Therefore, by puncturing one of a number of closely-arranged battery cells, it is possible to confirm whether the explosive force of the punctured battery cell is transferred to adjacent battery cells, causing a chain reaction of fire.

[0032] In this manner, the penetration safety test is performed under more severe conditions than the conventional battery cell penetration test, so that a battery cell with improved safety can be provided.

[0033] In addition, for battery cells whose safety against bottom penetration has been verified, additional safety verification against side penetration can be performed. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a vertical cross-sectional view of a portion of a battery module illustrating a conventional battery cell penetration test. [Diagram 2] FIG. 2 is a perspective view of a battery cell penetration test device according to the present invention. [Diagram 3] 3 is a vertical cross-sectional view showing an operating state of the battery cell penetration testing device of FIG. 2. [Figure 4] 1 is a vertical cross-sectional view of a portion of a battery module illustrating a battery cell penetration test using a battery cell penetration test device according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, in which a person having ordinary skill in the art to which the present invention pertains can easily carry out the present invention. However, in describing the operation principle of the preferred 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.

[0036] In addition, the same reference numerals are used throughout the drawings 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 the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0037] Furthermore, descriptions that limit or add specific elements are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0038] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0039] In addition, throughout the description of the present invention and the claims, unless otherwise specified, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0040] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0041] FIG. 2 is a perspective view of a battery cell penetration testing device according to the present invention.

[0042] Referring to FIG. 2, a battery cell penetration test device 300 according to the present invention includes a penetration portion 310 having a needle-shaped conductor 311 having a sharp needle shape, a guide portion 320 that pushes out the penetration portion 310 so that the needle-shaped conductor 311 pierces the side surface of the battery cell, and a holder 330 that houses the penetration portion 310 therein.

[0043] The guide portion 320 may be located outside the holder 330 or at least a portion of the guide portion 320 may be inserted into the holder 330. When the guide portion 320 moves downward and into the holder 330 to push the penetrating portion 310 toward the battery cell, the needle-shaped conductor 311 of the penetrating portion 310 penetrates the side of the battery cell, artificially causing an internal short circuit in the battery cell.

[0044] A horizontal bar 332 having the same length as the inner diameter of the holder is located inside the holder 330, and the horizontal bar 332 is disposed to pass across the upper part of the through-hole 310. Therefore, when the guide part 320 pushes the through-hole 310 from behind, the through-hole 310 can rotate forward with the horizontal bar 332 as a rotation axis.

[0045] 2, the holder 330 has a cylindrical structure, and the guide part 320 includes a front part 321 and a rear part 322 extending downward. The front part 321 and the rear part 322 are inserted into the holder 330 along the inner surface of the holder 330 to obtain the effect of pressing the penetration part 310, so that the outer surface 326 of the front part 321 and the outer surface 327 of the rear part 322 of the guide part 320 have curved surfaces corresponding to the cylindrical inner surface of the holder 330.

[0046] In this way, the holder structure having a cylindrical structure has an appearance similar to that of a cylindrical battery cell, so that when a plurality of cylindrical battery cells are mounted on a battery module, one of the cylindrical battery cells can be removed and a penetration test device can be inserted into that location to perform a penetration test.

[0047] Battery cells to which the battery cell penetration test device according to the present invention can be applied include cylindrical battery cells, pouch-type battery cells, and prismatic battery cells. Therefore, when the battery cell to be subjected to the penetration test is a prismatic battery cell or a pouch-type battery cell, the shape of the holder can be changed to an appearance of a prismatic battery cell or a shape similar to the appearance of a pouch-type battery cell. Alternatively, it goes without saying that the outer diameter of the holder in the penetration test device shown in FIG. 2 can be formed to a size corresponding to the thickness of the prismatic battery cell or the pouch-type battery cell and applied.

[0048] In one embodiment, a groove 325 is formed in the center of the inner surface 324 of the rear surface 322, and a protrusion 315 is formed on the outer surface 314 opposite to the first surface 312 of the through-hole 310. When the guide part 320 moves into the holder 330, the groove 325 can slide down while being coupled with the protrusion 315. Therefore, it is possible to prevent the direction of the descending guide part 320 from being deviated.

[0049] FIG. 3 is a vertical sectional view showing an operating state of the battery cell penetration testing device of FIG.

[0050] Referring to FIG. 3, the penetrating portion 310 includes a first surface 312 to which a needle-like conductor 311 is attached, and the first surface 312 has the form of a cut surface inclined with respect to an imaginary central axis CA of the penetrating portion 310.

[0051] An opening 331 is formed on the side surface of the holder 330 facing the pointed end of the needle-like conductor 311 of the penetrating portion 310. Therefore, when the guide portion 320 presses the penetrating portion 310, the penetrating portion 310 rotates clockwise, so that the needle-like conductor 311 of the penetrating portion 310 passes through the opening 331.

[0052] In other words, when the guide portion 320 is not pressing the through portion 310, the entire needle-shaped conductor 311 is located inside the holder 330, but when the guide portion 320 completely pushes out the through portion 310, the outer end of the needle-shaped conductor 311 that has passed through the opening 331 protrudes from the surface of the holder 330.

[0053] Here, a locking protrusion 313 may be added to the lower end of the through-portion 310 to prevent the needle-shaped conductor 311 from excessively protruding and penetrating into other battery cells.

[0054] A space 323 is formed between the front part 321 and the rear part 322 , and the through part 310 is inserted into the space 323 with the guide part 320 moving inside the holder 330 .

[0055] Specifically, the upper portion of the through portion 310 comes into close contact with the inner surface of the separated space 323 in the thickness direction A. When the guide portion 320 is inserted into the holder 330, the inner surface of the front portion 321 comes into close contact with the first surface 312 of the through portion 310 in parallel, and the inner surface 324 of the rear portion 322 comes into close contact with the outer surface 314 opposite the first surface in parallel.

[0056] In one embodiment, the inner surface 324 of the rear portion 322 has a planar shape, and the outer surface 314 opposite the first surface 312 of the penetrating portion 310 includes a planar portion that is in close contact with and parallel to the inner surface 324 of the rear portion 322 when the guide portion 320 moves into the holder 330.

[0057] Therefore, the flat surface of the rear surface portion 322 and the flat surface of the outer surface 314 opposite the first surface come into close contact with each other in parallel, and push the penetrating portion 310 in the clockwise direction.

[0058] FIG. 4 is a vertical cross-sectional view of a portion of a battery module illustrating a battery cell penetration test using a battery cell penetration test device according to the present invention.

[0059] The method for testing a penetration test of a battery cell according to the present invention includes the steps of preparing a battery cell stack including a plurality of battery cells 100, removing one of the battery cells 100 constituting the battery cell stack and inserting a penetration test device 300 into the portion from which the battery cell was removed, inserting a guide portion 320 of the penetration test device 300 into a holder 330, and being pressed by the guide portion 320 so that the needle-shaped conductor 311 of the penetration portion 310 penetrates a side surface of the battery cell 100.

[0060] 4, a battery cell stack including a plurality of battery cells 100 is disposed in a module case 200. The battery cells 100 shown in Fig. 4 are cylindrical battery cells, but the battery cell penetration test using the penetration test device according to the present invention can also be performed on a battery module including prismatic battery cells or pouch-type battery cells instead of cylindrical battery cells.

[0061] The end of the needle-shaped conductor 311 of the penetration test device 300 is positioned facing the side of the battery cell 100, so that when the guide portion 320 pushes out the penetration portion 310, the needle-shaped conductor 311 pierces the side of the battery cell 100.

[0062] In this way, when using the penetration testing device according to the present invention, it is possible to pierce the side of a battery cell even when multiple battery cells are arranged in a module case, making it possible to verify whether a chain fire will occur between adjacent battery cells.

[0063] Therefore, when the penetration testing device of the present invention is used in a battery cell penetration testing method, a battery cell with improved safety can be provided.

[0064] Those skilled in the art will appreciate that various applications and modifications within the scope of the present invention will be possible based on the above content. [Explanation of symbols]

[0065] 100 Battery Cells 110 battery cell bottom 120 Battery cell top 200 module case 300 Penetration Testing Device 310 Penetration 311 Needle conductor 312 1st page 313 Locking protrusion 314 Outer surface opposite to the first surface 315 Protrusion 320 Guide part 321 Front part 322 Rear part 323 Separate Space 324 Inner surface 325 Groove 326 Outer surface of front part 327 Outer surface of rear part 330 Holder 331 Aperture 332 Horizontal bar CA center axis

Claims

1. A penetration testing device for removing one battery cell from an assembled battery module, and then installing the battery cell in the portion from which the battery cell was removed to perform a penetration test on the battery cell in the assembled battery module, comprising: a feedthrough portion having a needle-like conductor with a pointed end; a guide portion that pushes out the penetrating portion so that the needle-shaped conductor pierces a side surface of the battery cell; a holder for receiving the penetrating portion therein, the holder having an opening formed on a side surface of the holder facing the pointed end of the needle-shaped conductor; Including, When the guide portion presses the through-hole, the needle-shaped conductor of the through-hole passes through the opening, A penetration testing device in which the end of the needle-shaped conductor that passes through the opening protrudes from the surface of the holder, thereby causing the needle-shaped conductor of the penetration portion to penetrate the side of the battery cell.

2. The penetration test device according to claim 1 , wherein the guide portion is configured to push the penetration portion while moving into the holder.

3. A horizontal bar having a length equal to the inner diameter of the holder is located inside the holder, The penetration test device according to claim 1 , wherein the penetrating portion is configured to rotate about the horizontal bar as a rotation axis when the guide portion presses the penetrating portion.

4. The guide portion includes a front portion and a rear portion extending downward, A space is formed between the front portion and the rear portion, The penetration test device according to claim 1 , wherein the penetration portion is inserted into the separated space with the guide portion moved to the inside of the holder.

5. The holder has a cylindrical structure, The penetration test device according to claim 4 , wherein the outer surface of the front surface and the outer surface of the rear surface of the guide portion have curved surfaces corresponding to a cylindrical inner surface of the holder.

6. the penetration portion includes a first surface on which a needle-like conductor is attached; The penetration testing device according to claim 1 , wherein the first surface has a form of a cut surface inclined with respect to a virtual central axis of the penetration portion.

7. The penetration testing device according to claim 4 or 5, wherein an upper portion of the penetration portion is in close contact with an inner surface of the separation space in a thickness direction.

8. The inner surface of the rear surface portion has a planar shape, The penetration testing device according to claim 4 or 5, wherein the outer surface opposite the first surface of the penetration portion includes a flat surface portion that is in close contact with the inner surface of the rear surface portion in parallel when the guide portion moves into the holder.

9. A method for testing a battery cell using the penetration test device according to claim 1, Providing a battery cell stack including a plurality of battery cells; removing one battery cell constituting the battery cell stack, and inserting the penetration test device into a portion from which the battery cell was removed; Inserting a guide portion of the penetration test device into the holder; a step of pushing the needle-shaped conductor of the penetration portion through a side surface of the battery cell by the guide portion; A method for penetration testing of a battery cell, comprising:

10. The method for performing a penetration test on a battery cell according to claim 9 , wherein the battery cells include a cylindrical battery cell, a pouch battery cell, and a prismatic battery cell.

11. The method for performing a penetration test on a battery cell according to claim 9 or 10, wherein an end of a needle-shaped conductor of the penetration test device is arranged to face a side surface of the battery cell.

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