Test piece preparation tool and test piece preparation method using the same

Abstract

The present invention relates to a test piece production jig for checking the shear force of a thermally conductive resin injected between a battery cell stack housed in a battery pack and a top plate provided to cover the upper part of the battery cell stack, the test piece production jig including a jig body having an upper end portion arranged perpendicular to the longitudinal direction of the test piece, and first and second lower end portions extending downward from both ends of the upper end portion, the first and second lower end portions being spaced apart by a distance wider than the width of the test piece, and a test piece production method using the test piece production jig.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0174940 filed December 5, 2023, and Korean Patent Application No. 10-2024-0176431 filed December 2, 2024, and all contents disclosed in the Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a test piece preparation jig and a test piece preparation method using the same, and more specifically to a battery pack containing multiple battery cells, which is injected with a thermally conductive resin to enhance the heat dissipation of the multiple battery cells, and a test piece preparation jig that allows observation of the shear force of the multiple battery cells and a top plate that are bonded via the thermally conductive resin, and a test piece preparation method using the same. [Background technology]

[0003] Rechargeable secondary batteries are widely used as an energy source for wireless mobile devices. Secondary batteries are also attracting attention as a power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs), which are being proposed as a solution to problems such as air pollution caused by existing gasoline and diesel vehicles that use fossil fuels.

[0004] While small mobile devices require a low operating voltage to operate a single device, medium- to large-sized devices such as automobiles require a high-output, large-capacity energy source. Therefore, medium- to large-sized battery modules and battery packs, which electrically connect multiple battery cells, are used.

[0005] The battery cells that make up medium- to large-sized battery modules and battery packs can be made up of rechargeable secondary batteries. The higher the output / capacity of a secondary battery, the more heat it generates during the charging and discharging process. If the heat generated during the charging and discharging process cannot be effectively removed, it can accelerate deterioration and, in some cases, cause fire or explosion.

[0006] FIG. 1 is an exploded perspective view of a typical battery pack.

[0007] 1, in a typical battery pack, a battery cell stack 20, in which multiple battery cells are stacked, is housed in a battery pack housing 10, and a top plate 40 is provided on the open top surface of the battery pack housing 10. A thermally conductive resin 30 is interposed in the space formed between the top plate 40 and the battery cell stack 20, completely filling the space.

[0008] As described above, a conventional method is to fill the space between the battery cell stack 20 and the top plate 40 with thermally conductive resin 30 to remove heat from the battery cell stack 20. Here, it is necessary to determine the amount of thermally conductive resin 30 to be applied or to test the shear strength of the battery cell stack 20 and the top plate 40 that are joined together with the thermally conductive resin 30 in between, and to determine the appropriate type, amount, and thickness of the thermally conductive resin.

[0009] However, currently, there is no experimental method that can observe the shear force of the battery cell and the top plate in a state where the battery cell and the thermally conductive resin are bonded together.

[0010] Therefore, in the past, a test piece for shear force testing was created by attaching a sample that replaces the battery case and top plate of a battery cell with a thermally conductive resin, and using this to check the shear force.

[0011] However, since it is difficult to uniformly apply the amount of thermally conductive resin, it is difficult to control the application area and thickness of the thermally conductive resin.

[0012] Therefore, there is a need for a test piece preparation tool for preparing a plurality of test pieces with uniform thermal conductive resin application and thickness, and a test piece preparation method using the same. Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention is intended to solve the problems described above, and aims to provide a test piece preparation tool and a test piece preparation method using the same that can prepare standardized test pieces by uniformly applying a thermally conductive resin in a uniform amount, area, and thickness. [Means for solving the problem]

[0014] To achieve this objective, the test specimen preparation jig of the present invention is a test specimen preparation jig for checking the shear force of a thermally conductive resin injected between a battery cell stack contained in a battery pack and a top plate provided to cover the upper part of the battery cell stack, and includes a jig body including an upper end portion arranged perpendicular to the longitudinal direction of the test specimen, and a first lower end portion and a second lower end portion extending downward from both ends of the upper end portion, the first lower end portion and the second lower end portion being positioned apart at a distance wider than the width of the test specimen.

[0015] The thickness of the jig body may be 1 mm to 5 mm.

[0016] The jig body may have an integral structure in which the upper end, the first lower end, and the second lower end are connected to one another.

[0017] The jig may further include a base jig on which the jig body is disposed, and at least one of the upper end, the first lower end, and the second lower end may be fixed to the base jig.

[0018] At least one of the upper end portion, the first lower end portion, and the second lower end portion may have one side end rotatably fixed to the base jig via a rotating member.

[0019] The base fixture can indicate the position where the test piece is to be placed.

[0020] A fixing member for fixing the test piece may be attached to the base jig.

[0021] The present invention also provides a method for producing a test piece using a test piece production jig, specifically including a first step of fixing the test piece, a second step of positioning the test piece production jig so that the upper end is perpendicular to the longitudinal direction of the test piece, a third step of providing thermally conductive resin on the test piece located between the first lower end and the second lower end, a fourth step of removing the thermally conductive resin provided in the third step that has adhered to the upper surfaces of the upper end, the first lower end, and the second lower end, a fifth step of attaching a metal plate to the thermally conductive resin of the fourth step, and a sixth step of removing the test piece production jig.

[0022] The first step may be to secure the test specimen with tape.

[0023] The third stage can provide a larger amount of thermally conductive resin than the space formed between the upper end, the first lower end, and the second lower end.

[0024] The test piece may be placed on a test piece position indicator displayed on the base jig, and the test piece may be fixed by a fixing member attached to the base jig.

[0025] A portion of the jig body including the upper end, the first lower end, and the second lower end includes a fixed portion fixed to the base jig, and the jig body can rotate around the fixed portion as a rotation axis.

[0026] The jig body can be rotated in a first direction so that the angle it forms with the base jig becomes larger, and a test piece can be placed at the bottom of the jig body, and then rotated in a second direction, which is the opposite direction to the first direction, so that the angle it forms with the base jig becomes 0, and a test piece can be placed below the upper end of the jig body.

[0027] The fifth step can include pressing the metal plate and drying the thermally conductive resin.

[0028] 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]

[0029] As described above, the test piece preparation jig and the test piece preparation method using the same according to the present invention can prepare test pieces with uniform application amount, area and thickness of thermally conductive resin. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is an exploded perspective view of a typical battery pack. [Figure 2] FIG. 1 is a plan view of a test piece fabrication jig according to a first embodiment. [Figure 3] FIG. 3 is a perspective view of FIG. 2. [Figure 4] FIG. 10 is a plan view of a test piece fabrication jig according to a second embodiment. [Figure 5] FIG. 10 is a plan view of a test piece fabrication jig according to a third embodiment. [Figure 6] 1A to 1C are diagrams showing the steps of a test piece preparation method using a test piece preparation jig according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, with reference to the accompanying drawings, embodiments will be described in detail so that those skilled in the art can easily practice the present invention. In describing the operation principle of the embodiments 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.

[0032] Throughout the drawings, the same reference numerals are used for parts having similar functions and actions. Throughout the specification, when a part is described as being connected to another part, this includes not only when it is directly connected, but also when it is indirectly connected via another element in between. Furthermore, when it is described as including a certain component, it does not mean that it excludes other components, but that it may further include other components, unless otherwise specified.

[0033] Descriptions that specify by limiting or adding elements are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0034] Throughout the description and claims of this invention, the singular includes the plural unless otherwise stated.

[0035] Throughout the description and claims of the present invention, the word "or" includes "and" unless otherwise specified. Thus, "including A or B" means three cases: including A, including B, or including both A and B.

[0036] The present invention will now be described in detail with reference to the accompanying drawings.

[0037] The test specimen creation jig according to the present invention is used to create test specimens for checking the shear strength of the battery cells and thermally conductive resin that make up the battery cell stack when manufacturing a battery pack by accommodating a battery cell stack in a battery pack housing, joining a top plate to cover the upper surface of the battery pack housing, and injecting thermally conductive resin between the battery cell stack and the top plate.

[0038] Specifically, the battery cell stack is formed by arranging multiple pouch-type battery cells in close contact with each other, and the bottoms of the cup portions of the pouch-type battery cells are arranged vertically relative to the bottom of the pack housing. Thermally conductive resin is injected into the top of the battery cell stack, and with the top of the battery cell stack covered, a top plate is placed on the thermally conductive resin, thereby sealing the pack housing.

[0039] FIG. 2 is a plan view of the test piece making jig according to the first embodiment, and FIG. 3 is a perspective view of FIG.

[0040] Referring to Figures 2 and 3, the test piece preparation jig according to the present invention includes a jig body 100 comprising an upper end portion 110 arranged perpendicular to the longitudinal direction Y of the test piece 200, and a first lower end portion 121 and a second lower end portion 122 extending downward from both ends of the upper end portion 110.

[0041] That is, the jig body 100 may have an integral structure in which the upper end portion 110, the first lower end portion 121, and the second lower end portion 122 are connected to one another, and may be configured in a substantially U-shape.

[0042] The test specimens created by the test specimen creation jig may be composed of samples that replace the pouch-type battery cell, plate, and thermally conductive resin, respectively, and may be composed of a test specimen composed of a laminate sheet as the pouch-type battery cell sample, a metal plate as the top plate sample, and a thermally conductive resin provided for attachment of the test specimen and the metal plate as the thermally conductive resin sample.

[0043] The test specimen created using the test specimen creation jig is a test specimen used to check the shear force of the pouch-type battery cell when the top plate and pouch-type battery cell are attached via a thermally conductive resin.

[0044] The test specimen described in the present invention can be the same as the laminate sheet used as the battery case of the pouch-type battery cell. Therefore, the test specimen includes an outer resin layer, a metal layer, and an inner adhesive layer, and may further include adhesive layers between the outer resin layer and the metal layer and between the metal layer and the inner adhesive layer.

[0045] The specific configuration of the laminate sheet can be any known laminate sheet for pouch-type battery cases without any restrictions, and therefore a description thereof will be omitted in this specification.

[0046] The thermally conductive resin is the same as the thermally conductive resin provided in the space between the battery cell stack and the top plate in the battery pack, and may be, for example, a polymeric substance such as epoxy, polyimide, or polystyrene, or may be a polymeric composite material containing metal particles such as Al, Ag, Cu, or Ni, ceramic particles such as AlN, Al2O3, BN, SiC, or BeO, or a carbon-based filler such as graphite, carbon nanotubes, carbon fibers, or graphene in a polymeric substance.

[0047] The metal plate can be made of the same material as the top plate, and can include, for example, aluminum.

[0048] In order to provide the thermally conductive resin 300 over the entire surface of one end of the test piece 200, the test piece 200 must be configured so that it can be seen between the first lower end 121 and the second lower end 122. Therefore, the distance W2 between the first lower end 121 and the second lower end 122 is positioned so as to be wider than the width W1 of the test piece.

[0049] Since thermally conductive resin is provided in the space formed inside the upper end portion 110, the first lower end portion 121, and the second lower end portion 122, the thickness of the jig body 100 can be formed to the desired thickness of the thermally conductive resin.

[0050] For example, the thickness D of the jig body can be set to 1 mm to 5 mm. If the thickness of the jig body is less than 1 mm, it may be difficult to ensure sufficient adhesive strength between the test piece 200 and the thermally conductive resin 300, which may cause problems in preparing the test piece, and if the thickness of the jig body is greater than 5 mm, the thermally conductive resin 300 may be made too thick, which may cause problems in fixing the test piece provided with the thermally conductive resin with a gripper of a UTM (Universal Testing Machine) for tensile testing, which is not preferable.

[0051] As a specific example, in order to make the area of ​​the thermally conductive resin applied to the test piece uniform and to perform shear force measurement tests using multiple test pieces under uniform conditions, the test piece preparation jig according to the present invention can make the area of ​​the thermally conductive resin applied to the test piece uniform by configuring the position of the thermally conductive resin applied to the test piece to be constant, i.e., the test piece can be configured to be positioned at a specific position in the lower part of the jig body.

[0052] FIG. 4 is a plan view of a test piece fabrication jig according to the second embodiment.

[0053] 4 , the test piece manufacturing jig according to the second embodiment further includes a base jig 500 on which the jig body 100 is disposed. Portions of the jig body 100, including the upper end portion 110, the first lower end portion 121, and the second lower end portion 122, include a fixing portion fixed to the base jig 500. Therefore, at least one of the upper end portion 110, the first lower end portion 121, and the second lower end portion 122 may be fixed to the base jig 500. Specifically, one side end of at least one of the upper end portion 110, the first lower end portion 121, and the second lower end portion 122 can rotate around the fixing portion as a rotation axis. For example, a first end of the first lower end portion 121 and the second lower end portion 122 may be coupled to the upper end portion 110, and a second end not coupled to the upper end portion 110 may include a fixing portion fixed to the base jig. The fixing portion may be formed of a pivot member 520, such as a hinge.

[0054] In this way, the jig body 100 can be fixed to the base jig 500 in a rotatable form using the rotating member 520, so that the angle formed between the lower surface of the jig body 100 and the upper surface of the base jig 500 can be formed within the range of 0 degrees to 180 degrees.

[0055] In FIG. 4, a rotating member 520 is provided at one side end of the first lower end 121 and the second lower end 122, and the first lower end 121 and the second lower end 122 are configured to be fixed to the base jig 500.

[0056] The jig body 100 can be configured such that the test piece 200 is placed at the bottom of the jig body 100 while rotated in a first direction d1 so that the angle it forms with the base jig 500 becomes larger, and then rotated in a second direction d2, which is the opposite direction to the first direction d1, so that the angle it forms with the base jig 500 becomes 0, and the test piece 200 is positioned below the upper end 110 of the jig body 100.

[0057] FIG. 5 is a plan view of a test piece fabrication jig according to the third embodiment.

[0058] 5, a test piece position indicator 510 is displayed on a base jig 500 to indicate the position where the test piece 200 is to be placed so that the thermally conductive resin can be provided at a specific position on the outer surface of the test piece 200, and the test piece 200 can be placed at the test piece position indicator 510 displayed on the base jig 500. Thus, the thermally conductive resin can be provided to have a specific area and thickness on the test piece placed at a specific position, thereby providing the thermally conductive resin with a constant area and thickness at a specific position on the outer surface of the test piece.

[0059] A fixing member for fixing the test specimen 200 may be attached to the base jig 500. For example, the test specimen 200 may be fixed onto the base jig via tape, or via a fixing member such as pliers 530 shown in FIG.

[0060] In this way, by providing the thermally conductive resin while the test piece 200 is placed in the test piece position display section 510 displayed on the base jig 500, it is possible to ensure that all test pieces created using the test piece creation jig have the same shape.

[0061] FIG. 6 is a diagram showing the steps of a test piece preparation method using a test piece preparation jig according to the present invention.

[0062] Referring to Figure 6, the test piece preparation method according to the present invention includes a first step of fixing the test piece 200, a second step of positioning the test piece preparation jig so that the upper end 110 is perpendicular to the longitudinal direction of the test piece 200, a third step of providing thermally conductive resin 300 on the test piece 200 located between the first lower end 121 and the second lower end 122, a fourth step of removing the thermally conductive resin 300 provided in the third step that is attached to the upper surfaces of the upper end 110, the first lower end 121, and the second lower end 122, a fifth step of attaching a metal plate 400 to the thermally conductive resin 300 in the fourth step, and a sixth step of removing the test piece preparation jig.

[0063] The first step may be a process of fixing the test specimen 200 with tape 201. As shown in Fig. 6(a), the tape 201 may be attached to each of the upper and lower ends of the test specimen 200, but prior to providing the thermally conductive resin 300, the tape 201 attached to the lower end where the thermally conductive resin 300 will be provided may be removed in advance as shown in Fig. 6(b).

[0064] In the third step, a larger amount of thermally conductive resin 300 than the space can be provided so as to completely fill the space formed between the upper end portion 110, the first lower end portion 121, and the second lower end portion 122. Therefore, in the fourth step, the excess thermally conductive resin 300 remaining after filling the space, that is, the resin attached to the upper surfaces of the upper end portion 110, the first lower end portion 121, and the second lower end portion 122, is removed.

[0065] Meanwhile, in the test piece manufacturing jigs according to the first to third embodiments, the jig body 100 has an open lower end at the first lower end 121 and the second lower end 122, which is opposite to the upper end connected to the upper end 110, but may also be configured as a rectangular frame with a closed lower end. In this case, the area to which the thermally conductive resin 300 is applied can be configured to be the same as the area of ​​the space formed inside the rectangular frame.

[0066] The fifth step includes pressing the metal plate and drying the thermally conductive resin.

[0067] In the present invention, since the thermally conductive resin is provided in an amount corresponding to the space formed inside the jig body, it is possible to provide a thermally conductive resin of uniform thickness even if there is a deviation in the force pressing against the metal plate.

[0068] The following description will be given with reference to the present embodiment, but this is for the purpose of making the present invention easier to understand, and the scope of the present invention is not limited thereto.

[0069] <Example> Test specimens were prepared for carrying out shear strength measurement tests according to standard ASTM D1002.

[0070] A 2mm thick laminate sheet used for pouch-type battery cases was cut to a size of 25.4mm wide x 101.6mm long to prepare a test specimen, and a thermally conductive resin was applied to the test specimen using a test specimen preparation jig according to the present invention. The thermally conductive resin was applied to the test specimen to a size of 25.4mm wide x 25.4mm long x 2mm thick, and a metal plate was attached to the thermally conductive resin, which was then cured at 25°C for at least 24 hours.

[0071] A metal plate is attached to the lower jig of the UTM, and a test specimen is fixed to the upper jig. The test specimen is then pulled in opposite directions to measure the force at which it comes off the metal plate.

[0072] The shear force was measured to be over 1.4 MPa.

[0073] In this way, when using the test specimen preparation jig according to the present invention, it is possible to provide a thermally conductive resin to the test specimen so that it has a uniform size and thickness. Therefore, it is possible to test the shear force of the battery cell stack and top plate without disassembling the battery pack and determine the appropriate type, application amount, thickness, etc. of the thermally conductive resin.

[0074] In a battery pack in which a thermally conductive resin is filled on a battery cell stack accommodated in a battery pack housing and a top plate is provided to seal it, if the shear force of the battery cell stack and top plate needs to be controlled to 1.4 MPa or more, by creating a test specimen using a test specimen creation jig as in the example and conducting an experiment, accurate results can be obtained in a simple manner without the need to disassemble the battery pack.

[0075] Those skilled in the art will appreciate that various modifications and variations within the scope of the present invention will be apparent to those skilled in the art based on the above content. [Explanation of symbols]

[0076] 10 Battery pack housing 20 Battery cell stack 30, 300 Thermally conductive resin 40 Top Plate 100 Jig body 110 Upper end 121 1st lower end 122 Second lower end 200 specimens 201 Tape 400 metal plate 500 base jig 510 Test piece position display 520 Rotating member 530 Finally D Thickness of the jig body W1 Width of test piece W2: Distance between the first and second lower ends

Claims

1. A test piece creation jig for checking the shear strength of a thermally conductive resin injected between a battery cell stack housed in a battery pack and a top plate provided to cover an upper portion of the battery cell stack, comprising: A jig body, an upper end portion disposed perpendicular to the longitudinal direction of the test piece; a jig body including a first lower end portion and a second lower end portion extending downward from both ends of the upper end portion, The test piece preparation jig, wherein the first lower end portion and the second lower end portion are positioned apart by a distance wider than the width of the test piece.

2. 2. The test piece producing jig according to claim 1, wherein the thickness of the jig body is 1 mm to 5 mm.

3. 2. The test piece producing jig according to claim 1, wherein the jig body has an integral structure in which the upper end portion, the first lower end portion, and the second lower end portion are connected to one another.

4. Further including a base jig on which the jig body is disposed, The test piece production jig according to claim 1 , wherein at least one of the upper end portion, the first lower end portion, and the second lower end portion is fixed to the base jig.

5. 5. The test piece production jig according to claim 4, wherein one side end of at least one of the upper end portion, the first lower end portion, and the second lower end portion is fixed to the base jig in a rotatable manner via a rotating member.

6. 5. The test piece production jig according to claim 4, wherein the base jig indicates a position where the test piece is to be placed.

7. 5. The test piece producing jig according to claim 4, wherein a fixing member for fixing the test piece is attached to the base jig.

8. A method for producing a test piece using the test piece production jig according to any one of claims 1 to 7, comprising: a first step of fixing the test specimen; a second step of placing the test piece preparation jig so that the upper end portion of the test piece is perpendicular to the longitudinal direction of the test piece; a third step of providing a thermally conductive resin to the test specimen located between the first lower end and the second lower end; a fourth step of removing the thermal conductive resin provided in the third step from the upper end portion, the first lower end portion, and the second lower end portion; a fifth step of attaching a metal plate to the thermally conductive resin of the fourth step; and a sixth step of removing the test piece preparation jig.

9. 9. The method for preparing a test strip according to claim 8, wherein the first step is a step of fixing the test strip with tape.

10. 9. The test piece preparation method of claim 8, wherein the third step is a step of providing a thermally conductive resin in an amount greater than the space formed between the upper end, the first lower end, and the second lower end.

11. The test piece is placed on a test piece position indicator displayed on a base jig; 9. The test piece producing method according to claim 8, wherein the test piece is fixed by a fixing member attached to the base jig.

12. a part of the jig body including the upper end, the first lower end, and the second lower end includes a fixing portion fixed to the base jig; The test piece manufacturing method according to claim 11 , wherein the jig body rotates around the fixing portion as a rotation axis.

13. 13. A test piece creation method as described in claim 12, wherein the jig body is rotated in a first direction so that the angle it forms with respect to the base jig becomes larger, and a test piece is placed at the bottom of the jig body, and then rotated in a second direction opposite to the first direction so that the angle it forms with respect to the base jig becomes 0, and the test piece is placed below the upper end of the jig body.

14. 9. The method for producing a test piece according to claim 8, wherein the fifth step includes the steps of pressing the metal plate and drying the thermally conductive resin.

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