Apparatus for impact test of battery cell and method for impact test of battery cell using the same

Abstract

The present invention relates to a battery cell collision test device comprising a jig capable of easily fixing the battery cell in a narrow side direction during a battery cell collision test, and a battery cell collision test method using the same.

Description

Technology Field

[0001] The present invention relates to a battery cell collision test device and a battery cell collision test method using the same. Background Technology

[0003] As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly rising, and accordingly, research is being conducted on secondary batteries capable of meeting various requirements.

[0004] In terms of battery shape, there is high demand for prismatic and pouch-type rechargeable batteries, which are thin and suitable for applications in products such as mobile phones; in terms of materials, there is high demand for lithium-ion batteries and lithium-ion polymer batteries, which possess advantages such as high energy density, discharge voltage, and output safety.

[0005] These secondary batteries can be classified into cylindrical, prismatic, and pouch-type cells depending on their shape. Among them, pouch-type cells are attracting significant attention because they can be stacked with high integration density, have high energy density per unit weight, are inexpensive, and are easy to deform.

[0006] Meanwhile, a battery cell is constructed by embedding an electrode assembly, consisting of a positive electrode, a negative electrode, and a separator placed between them, inside a battery case. However, electrode plates, such as the positive or negative electrode, can deform upon external impact, and such deformation is a primary cause of ignition or explosion within the battery cell. Accordingly, rigidity against external impact is recognized as a key factor in determining the quality of a battery cell.

[0007] In this way, in order to determine the quality of the battery cells against external shock, an impact is artificially applied to the battery cells to determine their quality against external shock.

[0008] FIGS. 1 to 3 are schematic diagrams illustrating the collision test process of a battery cell. Referring to FIGS. 1 and 2, the collision test for the battery cell (1) was performed by dropping an object of a predetermined weight from a specific height while the battery cell (1) was fixed, thereby applying an impact to the battery cell. The collision test of the battery cell (1) is a test of the wide sides and narrow sides of the battery cell, and involves applying an impact by dropping an object weighing 9.1 kg from a height of approximately 61 cm onto the battery cell (1) (Fig. 1: Collision test of the wide sides of the battery cell, Fig. 2: Collision test of the narrow sides of the battery cell).

[0009] Meanwhile, in the past, when performing a test to apply impact to the narrow sides of a battery cell (1), there was no device provided to fix the battery cell (1). To this end, in the past, a rectangular plate (2) had to be attached to both sides of the battery cell (1) to set the battery cell (1) vertically, and the battery cell (1) had to be fixed by wrapping it with tape (3) to perform the above experiment (see FIG. 3).

[0010] Therefore, there is a need to develop a crash test device that includes a jig capable of easily securing the battery cell in a lateral direction during a crash test. Prior art literature

[0012] Korean Registered Patent No. 10-1954975 The problem to be solved

[0013] The present invention aims to solve the above-mentioned problems by providing a battery cell collision test device comprising a jig capable of fixing the battery cell in a narrow side direction, and a battery cell collision test method using the same. means of solving the problem

[0015] The present invention provides a crash test device for a battery cell. In one example, the crash test device for a battery cell according to the present invention includes a jig on which a battery cell is placed and an impact member comprising a striking weight provided on the upper part of the jig, which free-falls toward the jig to impact the battery cell. In a specific example, the jig includes a base on which a battery cell is placed and first and second plates disposed on one surface of the base to support both sides with the battery cell in between so that the battery cell is mounted in an upright state.

[0016] In another example, the jig includes a pressure plate positioned between the first and second plates along the longitudinal direction of the first and second plates to apply pressure to one side of the battery cell. In this case, the pressure plate may be structured to be fastened to the first or second plate by an elastic pressure member.

[0017] In another example, the jig includes first and second pressure plates that are spaced apart from each other and positioned along the longitudinal direction of the first and second plates between the first and second plates to apply pressure to both sides of a battery cell. In this case, the first plate and the first pressure plate may be fastened by a first elastic pressure member, and the second plate and the second pressure plate may be fastened by a second elastic pressure member.

[0018] In a specific example, the elastic pressure member includes a coil spring or a leaf spring.

[0019] In one example, the jig in the collision test device for a battery cell according to the present invention includes first and second support members disposed at both ends of the first and second plates to support both sides of a battery cell mounted between the first and second plates. In a specific example, the first and second support members have a structure insulated on the inner surface that contacts the battery cell.

[0020] In one example, the first and second plates of the jig have a height ranging from 3 / 10 to 7 / 10 based on the total height of the battery cell being housed.

[0021] Furthermore, in the impact test device for a battery cell according to the present invention, the impact member may further include a guide bar that guides the impact weight to fall vertically toward the battery cell placed on the jig. In a specific example, the impact test device for a battery cell according to the present invention further includes a horizontal support located on the upper part of the jig to support a pressure plate; and a vertical support connecting the horizontal support and the base of the jig.

[0023] The present invention provides a method for a collision test of a battery cell using the battery cell collision test device described above.

[0024] In one example, the impact test method for a battery cell according to the present invention includes the step of free-falling a striking weight of an impact member toward a battery cell placed on a jig; and the step of determining whether the battery cell is defective based on whether the battery cell ignites or explodes. Effects of the invention

[0026] According to the battery cell collision test device and battery cell collision test method using the same of the present invention, the battery cell is included in a jig capable of fixing the battery cell in a lateral direction, thereby having the advantage of easily fixing the battery cell in a lateral direction (narrow sides) during a battery cell collision test. Brief explanation of the drawing

[0028] Figure 1 is a diagram schematically showing the crash test process for the wide sides of a battery cell. Figure 2 is a diagram schematically showing the crash test process for the narrow sides of a battery cell. Figure 3 is a schematic diagram showing a conventional method of fixing a battery cell during a collision test on the narrow sides of the battery cell. FIG. 4 is a schematic diagram of a collision test device for a battery cell according to one embodiment of the present invention. FIG. 5 is a schematic diagram showing a jig of a collision test device for a battery cell according to one embodiment of the present invention. FIG. 6 is a schematic diagram showing a jig of a collision test device for a battery cell according to another embodiment of the present invention. FIG. 7 is a schematic diagram showing a jig of a collision test device for a battery cell according to another embodiment of the present invention. FIG. 8 is a flowchart of a collision test method for a battery cell according to one embodiment of the present invention. Specific details for implementing the invention

[0029] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0030] In this application, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only cases where it is "immediately above" the other part, but also cases where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only cases where it is "immediately below" the other part, but also cases where there is another part in between. Additionally, in this application, being placed "on" may include cases where it is placed on the lower part as well as on the upper part.

[0032] The present invention provides a battery cell collision test device and a battery cell collision test method using the same.

[0033] In one example, the impact test device for a battery cell according to the present invention comprises: a jig on which a battery cell is placed; and an impact member comprising a striking weight provided on the upper part of the jig and free-falling toward the jig to impact the battery cell. In this case, the jig is characterized by including a base on which a battery cell is placed and first and second plates disposed on one surface of the base to support both sides with the battery cell in between so that the battery cell is mounted in an upright state.

[0034] Typically, impact tests on battery cells were performed by dropping an object of a predetermined weight from a specific height while the battery cell was fixed in place to apply an impact. Specifically, the impact test on the battery cell involved testing the wide sides and narrow sides of the battery cell, which involved dropping an object weighing 9.1 kg from a height of approximately 61 cm to apply an impact. At this time, the defect status of the battery cell was determined by observing whether the battery cell ignited or exploded due to the impact. Meanwhile, conventionally, there was no device to fix the battery cell in the lateral direction when performing the impact test on the sides of the battery cell. To address this, conventionally, rectangular plates had to be attached to both sides of the battery cell to set it upright, and the battery cell had to be fixed by wrapping it with tape to perform the test.

[0035] Accordingly, the present invention provides a battery cell collision test device and a battery cell collision test method using the same. According to the battery cell collision test device and the battery cell collision test method using the same of the present invention, there is an advantage that the battery cell can be easily fixed in the narrow sides during a battery cell collision test.

[0036] In the present invention, the "battery cell" subject to test is a secondary battery, specifically a pouch-type battery cell or a pouch-type unit cell, in which an electrode assembly having a positive / separator / negative structure may be embedded in a laminate sheet outer material in a state connected to electrode leads formed outside the outer material. The electrode leads may be drawn out to the outside of the sheet and may extend in the same direction or in opposite directions. In the drawings of the present invention, for the convenience of illustration, only a pouch-type battery cell having a pair of electrode leads drawn out in opposite directions is illustrated; however, the battery cell applied to the battery cell collision test device and method according to the present invention is not necessarily limited to this, and it is also possible for a pair of electrode leads to be drawn out in the same direction.

[0038] Hereinafter, a collision test device for a battery cell according to the present invention and a collision test method for a battery cell using the same will be described in detail with reference to the drawings.

[0040] <제1 실시 형태>

[0041] FIG. 4 is a schematic diagram of a battery cell collision test device according to one embodiment of the present invention, and FIG. 5 is a schematic diagram showing a jig of a battery cell collision test device according to one embodiment of the present invention.

[0042] Referring to FIGS. 4 and 5, the battery cell impact test device (100) according to the present invention comprises: a jig (110) on which a battery cell (10) is placed; and an impact member (120) including a striking weight (121) provided on the upper part of the jig (110) and free-falling toward the jig (110) to impact the battery cell (10).

[0043] In a specific example, the jig (110) is configured to include a base (111) on which a battery cell (10) is placed, and first and second plates (112, 113) positioned on one side of the base (111) to support both sides with the battery cell (10) in between so that the battery cell (10) is mounted in an upright state. The first and second plates (112, 113) serve to support the battery cell (10) so that the battery cell (10) can be mounted on the jig (110) in an upright state. Meanwhile, it is preferable that the battery cell (10) housed in the jig (110) comes into contact with the inner surfaces of the first and second plates (112, 113). However, it is preferable that the gap between the first and second plates (112, 113) corresponds to the thickness of the battery cell (10) being tested, or is greater than the thickness of the battery cell (10).

[0044] In the battery cell collision test device (100) according to the present invention, the first and second plates (112, 113) support the battery cell (10), thereby allowing the battery cell (10) to be easily fixed and the test to be performed during the collision test. In particular, the jig (110) can easily fix the battery cell (10) in the lateral direction during the collision test on the narrow sides of the battery cell (10).

[0045] In one example, in a collision test device (100) for a battery cell according to the present invention, the jig (110) includes first and second support members (114, 115) that are positioned at both ends of the first and second plates (112, 113) and support both sides of a battery cell (10) mounted between the first and second plates (112, 113). The first and second support members (114, 115) are connected and installed at both ends of the first and second plates (112, 113). The first and second support members (114, 115) are installed in a direction orthogonal to the first and second plates (112, 113) and serve to fix both sides of the battery cell (10) so that the upright battery cell (10) does not move. In a specific example, the first and second support members (114, 115) are formed symmetrically on both sides of the first and second plates (112, 113) and serve to fix the battery cell (10) so that it does not slide during a collision test of the battery cell (10).

[0046] Meanwhile, the height of the first and second support members (114, 115) may be lower than the height of the electrode lead in the battery cell (10) mounted on the jig (110). Furthermore, the first and second support members (114, 115) may support the electrode lead of the battery cell (10).

[0047] The first and second support members (114, 115) are configured to fix the side of the battery cell (10) that is not in contact with the first and second plates (112, 113), and may have an insulated structure on the inner surface that contacts the battery cell (10). For example, the inner surface of the first and second support members (114, 115) may have an insulated structure made of an elastic or rubber material. This is to prevent a disconnection or short circuit of the electrode lead portion of the battery cell (10) that is in contact with the first and second plates (112, 113).

[0048] In one example, the first and second plates (112, 113) of the battery cell impact test device (100) according to the present invention may have a structure having a height in the range of 3 / 10 to 7 / 10 based on the total height of the battery cell (10) housed in the jig (110). For example, the height of the first and second plates (112, 113) is intended to expose the impact area of ​​the battery cell (10), and may have a structure having a height in the range of 4 / 10 to 5 / 10 based on the total height of the battery cell (10) housed in the jig (110). Meanwhile, if the height of the first and second plates (112, 113) is less than 3 / 10 based on the total height of the battery cell (10), a problem may arise in which the battery cells (10) housed between the first and second plates (112, 113) cannot be easily mounted. Furthermore, if the height of the first and second plates (112, 113) exceeds 7 / 10 of the total height of the battery cell (10), the height of the first and second plates is too high, so when a striking weight is dropped onto the battery cell (10) housed in the jig (110), it may not be possible to provide a collision to the desired area. Therefore, the height of the first and second plates (112, 113) is preferably within the range described above.

[0049] In one example, the battery cell impact test device (100) according to the present invention includes an impact member (120) comprising a striking weight (121) that is provided on the upper part of a jig (110) and falls freely toward the jig (110) to impact the battery cell (10).

[0050] In a specific example, the impact member (120) further includes a guide bar (122) that guides the impact weight (121) to fall vertically toward the battery cell (10) placed on the jig (110). The guide bar (122) may be provided vertically in an upward direction on the upper surface of the jig (110) or on the base (111) of the jig (110). Specifically, the guide bar (122) may be installed in an upward and downward direction on the upper surface of the jig (110) and on the lower surface of the horizontal support (123) to be described later. More specifically, the impact weight (121) may move vertically along the guide bar (122).

[0051] Furthermore, the battery cell collision test device (100) according to the present invention may further include a horizontal support (123) located on the upper part of the jig (110) to support a guide bar (122), and a vertical support (124) connecting the horizontal support (123) and the base (111) of the jig (110). In the present invention, the impact member (120) that strikes the battery cell (10) housed in the jig (110) may be an impact member (120) used in a conventional battery cell collision test device (100), and a detailed description thereof is omitted.

[0052] The battery cell collision test device (100) according to the present invention includes a jig (110) capable of fixing the battery cell (10) in a lateral direction, so that the battery cell (10) can be easily fixed in a lateral direction (narrow sides) during a battery cell collision test, and thus has the advantage of easily performing a battery cell collision test.

[0054] <제2 실시 형태>

[0055] FIG. 6 is a schematic diagram showing a jig of a battery cell collision test device according to another embodiment of the present invention. Referring to FIG. 6, the jig (210) of the battery cell collision test device according to the present invention comprises a pressure plate (216) disposed along the longitudinal direction of the first and second plates (212, 213) between the first and second plates (212, 213).

[0056] At this time, the pressure plate (216) is structured to be connected to the first or second plate (212, 213) by an elastic pressure member (217). The pressure member (217) is intended to press the battery cell (20) standing upright between the first and second plates (212, 213) to accommodate it more easily and fix it more firmly. Meanwhile, the pressure plate (216) may have the same height as the first and second plates (212, 213), and specifically, may have a height in the range of 3 / 10 to 7 / 10 based on the total height of the battery cell (20).

[0057] In one example, the elastic pressure member (217) of the jig (210) may be a member that applies a constant pressure in the direction in which the battery cell (20) is seated. In a specific example, the elastic pressure member (217) is a coil spring or a leaf spring, and for example, the elastic pressure member (217) may be a coil spring. The coil spring refers to a compression spring, which is a spring having a force that resists compression.

[0059] <제3 실시 형태>

[0060] FIG. 7 is a schematic diagram showing a jig of a battery cell collision test device according to another embodiment of the present invention. Referring to FIG. 7, the jig (310) of the battery cell collision test device according to the present invention includes first and second pressure plates (3161, 3162) that are spaced apart from each other and are arranged along the longitudinal direction of the first and second plates (312, 313) between the first and second plates (312, 313). At this time, the first plate (312) and the first pressure plate (3161) are fastened by a first elastic pressure member (3171). Also, the second plate (313) and the second pressure plate (3162) may be structured to be fastened by a second elastic pressure member (3172).

[0061] As the description of the first and second pressure plates (3161, 3162) and the first and second elastic pressure members (3171, 3172) has been explained previously, the description of the specific configuration or operating mechanism will be omitted.

[0062] Meanwhile, as described above, the first and second pressure plates (3161, 3162) and the first and second elastic pressure members (3171, 3172) are intended to press the battery cell (30) standing upright between the first and second plates (312, 313) to store it more safely and fix it more firmly.

[0064] <제4 실시 형태>

[0065] FIG. 8 is a flowchart of a collision test method for a battery cell according to one embodiment of the present invention.

[0066] Referring to FIG. 8, the collision test method for a battery cell according to the present invention includes the step (S10) of free-falling a striking weight of an impact member toward a battery cell placed on a jig; and the step (S20) of determining whether the battery cell is defective based on whether the battery cell ignites or explodes.

[0067] The crash test method for a battery cell according to the present invention can be performed using the battery cell crash test device described above, or through a commonly known crash test method.

[0068] For example, the impact test method for a battery cell according to the present invention prepares a battery cell discharged to a 50% charge state using a constant current of 0.2 It A. Then, the battery cell is placed in the jig described above and positioned upright in a vertical direction. Next, a weight of 9.1 kg is dropped onto the battery cell from a height of 610 ± 25 mm above the battery cell placed in the jig. At this time, it is possible to check whether ignition or explosion occurs after the weight is dropped. Here, the weight refers to a striking weight.

[0069] Meanwhile, in the above free-falling step (S10), an object such as a round bar crossing the center of the battery cell to be tested may be placed on the upper part of the battery cell, and a weight (impact weight) to be dropped may be dropped onto the round bar. For example, the round bar may be a stainless steel round bar with a diameter of (15.8 ± 0.1) mm. However, it is not limited thereto. Meanwhile, the round bar may be fixed so as not to move using a separately provided elastic body or a fixed body.

[0070] If ignition or explosion is detected after the above-mentioned heavy object is dropped, the battery cell under test may be determined to be defective.

[0071] The battery cell collision test method of the present invention may utilize the battery cell collision test device described above, and in particular, the test can be performed after easily fixing the battery cell in a narrow side direction. Accordingly, the stability test can be easily performed and the accuracy can be increased.

[0073] Although preferred embodiments of the present invention have been described above with reference to the drawings, those skilled in the art or those with ordinary knowledge in the relevant technical field will understand that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the invention as described in the claims.

[0074] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims. Explanation of the symbols

[0076] 1, 10, 20, 30: Battery cells 2: Plate 3: Tape 100: Battery cell crash test device 110, 210, 310: Jig 111, 211, 311: Bass 112, 212, 312: First plate 113, 213, 313: Second plate 114: First supporting member 115: Second support member 120: Absence of impact 121: Hitting point 122: Guide Bar 123: Horizontal support 124: Vertical support 216: Pressure plate 217: Elastic pressure member 3161: First pressure plate 3162: Second pressure plate 3171: First elastic pressure member 3172: Second elastic pressure member

Claims

Claim 1 A battery cell impact test device having a structure comprising: a jig on which a battery cell is placed; and an impact member including a striking weight provided on the upper part of the jig and free-falling toward the jig to impact the battery cell; wherein the jig comprises: a base on which a battery cell is placed; first and second plates disposed on one surface of the base and supporting both sides with the battery cell between them so that the battery cell is mounted in an upright state; first and second pressure plates disposed between the first and second plates along the longitudinal direction of the first and second plates and spaced apart from each other to press both sides of the battery cell; a first elastic pressure member connecting the first plate and the first pressure plate; a second elastic pressure member connecting the second plate and the second pressure plate; and first and second support members disposed at both ends of the first and second plates and supporting both sides of the battery cell mounted between the first and second plates. Claim 2 A battery cell collision test device according to claim 1, wherein the jig comprises a pressure plate disposed between the first and second plates along the longitudinal direction of the first and second plates to press one side of the battery cell, and said pressure plate is structured to be fastened to the first or second plate by an elastic pressure member. Claim 3 delete Claim 4 In claim 2, the elastic pressure member is a collision test device for a battery cell, which is a coil spring or a leaf spring. Claim 5 delete Claim 6 In claim 1, the first and second support members are a battery cell impact test device having a structure insulated on the inner surface in contact with the battery cell. Claim 7 A battery cell impact test device according to claim 1, wherein the first and second plates have a structure having a height in the range of 3 / 10 to 7 / 10 based on the total height of the battery cell housed in the jig. Claim 8 A battery cell impact test device according to claim 1, wherein the impact member further comprises a guide bar that guides the impact weight to fall vertically toward a battery cell placed on a jig. Claim 9 A battery cell impact test device according to claim 8, further comprising: a horizontal support located on the upper part of the jig to support a pressure plate; and a vertical support connecting the horizontal support and the base of the jig. Claim 10 A method for a collision test of a battery cell using a collision test device for a battery cell according to claim 1. Claim 11 A method for a collision test of a battery cell according to claim 10, comprising: a step of free-falling a striking weight of an impact member toward a battery cell seated on a jig; and a step of determining whether the battery cell is defective based on whether the battery cell ignites or explodes.

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