Secondary battery testing apparatus and testing method

Abstract

A test apparatus and a test method for a secondary battery are disclosed. According to the present disclosure, a test apparatus for a secondary battery is provided, comprising a pressure sheet disposed on the outer surface of an electrode assembly, wherein the pressure sheet is provided as a flexible sheet that wraps around the outer surface and is configured to press the outer surface toward the central axis of the electrode assembly while making close surface contact with the outer surface according to an external force applied in the longitudinal direction.

Description

Technology Field

[0001] The embodiments of the present disclosure relate to a test apparatus and a test method for a secondary battery. Background Technology

[0002] A secondary battery is a means of energy storage capable of charging and discharging through electrochemical reactions. Secondary batteries are used in various fields that utilize electrical energy. For example, secondary batteries are widely used in the field of mobile devices such as mobile phones, laptops, and tablets, and broader applications are being sought in the field of transportation equipment such as vehicles, aircraft, and ships. In addition, demand for secondary batteries is increasing in the field of Energy Storage Systems (ESS) for the utilization of surplus power.

[0003] Some secondary batteries may be equipped with positive and negative electrodes alternately arranged with a separator in between. For example, in a cylindrical battery, positive and negative electrodes alternately arranged with a separator in between are wound into a cylinder to form an electrode assembly, and such an electrode assembly may be housed inside a case. Secondary batteries may be manufactured through multiple process steps, and external forces applied at each step, various by-products generated during processing, and foreign substances introduced from the external environment can cause defects in the manufactured secondary battery. For example, various by-products generated during processing may enter the electrode assembly, damaging the separator and causing a short circuit. Accordingly, it is necessary to properly determine whether the manufactured secondary battery is defective by measuring factors such as leakage current.

[0004] The foregoing description is provided to aid in understanding the technical background of the present disclosure. Accordingly, the foregoing description should not be interpreted as reducing, limiting, or restricting the technical concept of the present disclosure. Furthermore, the contents described or suggested in the foregoing description do not necessarily constitute prior art. The foregoing description may include contents that do not constitute prior art. The problem to be solved

[0005] Some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery.

[0006] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery capable of appropriately determining whether there is a processing defect in the secondary battery.

[0007] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery that can be appropriately utilized for a cylindrical electrode assembly.

[0008] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery that can improve the reliability of test results.

[0009] Some embodiments of the present disclosure may be widely applied in green technology fields such as electric vehicles, battery charging stations, and other battery-based solar and wind power generation. Additionally, some embodiments of the present disclosure may be used in eco-friendly electric vehicles, hybrid vehicles, etc., to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0010] However, the technical problems that the embodiments of the present disclosure aim to solve are not necessarily limited to the technical problems mentioned above. Other technical problems not mentioned will be clearly understood by those skilled in the art to which the present disclosure pertains from other descriptions in the specification, such as the detailed description. means of solving the problem

[0011] According to one aspect of the present disclosure, a test apparatus for a secondary battery may be provided, comprising a pressure sheet disposed on the outer surface of an electrode assembly, wherein the pressure sheet is provided as a flexible sheet that wraps around the outer surface and is configured to press the outer surface toward the central axis of the electrode assembly while making surface contact in close contact with the outer surface according to an external force applied in the longitudinal direction.

[0012] In some embodiments, the electrode assembly may be provided with a positive electrode and a negative electrode alternately arranged with a separator in between, wound cylindrically around the central axis.

[0013] In some embodiments, the test device for the secondary battery may include a measuring device configured to measure one or more of the leakage current and insulation resistance of the electrode assembly while the pressure sheet is pressing the outer surface.

[0014] In some embodiments, the pressure sheet may include an electrically insulating material.

[0015] In some embodiments, the pressure sheet may include a first sheet region extending longitudinally from a first end; and a second sheet region extending longitudinally from an end of the first sheet region to a second end corresponding to the first end.

[0016] In some embodiments, the first sheet region has a slit, and the second sheet region can be inserted and fastened to be movably in the longitudinal direction into the slit.

[0017] In some embodiments, the first sheet area may be provided to have a first width, and the second sheet area may be provided to have a second width smaller than the first width.

[0018] In some embodiments, the second width may be formed to be equal to the height of the electrode assembly or to be larger than the height by a certain amount.

[0019] In some embodiments, the pressure sheet may be configured to apply an external force in a first direction to a first end and an external force in a second direction opposite to the first direction to a second end corresponding to the first end, thereby applying pressure to the outer surface.

[0020] In some embodiments, the pressure sheet may include a first pressure sheet provided to wrap around a portion of the outer surface in a first rotational direction; and a second pressure sheet provided to wrap around another portion of the outer surface in a second rotational direction opposite to the first rotational direction.

[0021] In some embodiments, the first and second pressure sheets are each provided in multiple numbers, and the multiple first and second pressure sheets may be alternately and repeatedly arranged along the height direction of the electrode assembly.

[0022] In some embodiments, the first pressure sheet may be provided to apply pressure to a portion of the outer surface by applying an external force in a direction corresponding to the first rotational direction, and the second pressure sheet may be provided to apply pressure to another portion of the outer surface by applying an external force in a direction corresponding to the second rotational direction.

[0023] In some embodiments, the bracket may include a first end portion of each of the first and second pressure sheets supported by a bracket, wherein the bracket may include a first slit into which the second end portion of the first pressure sheet is inserted so as to be movable in the longitudinal direction; and a second slit into which the second end portion of the second pressure sheet is inserted so as to be movable in the longitudinal direction.

[0024] According to another aspect of the present disclosure, a method for testing a secondary battery may be provided, comprising the steps of: placing a pressure sheet, which is provided as a flexible sheet, on the outer surface of an electrode assembly; applying an external force to the pressure sheet and pressing the outer surface while the pressure sheet is in close contact with the outer surface; and measuring one or more of the leakage current and insulation resistance of the electrode assembly in the pressured state.

[0025] In some embodiments, the test method for the secondary battery may include the step of releasing the external force and separating the electrode assembly from the pressure sheet when the measurement step is completed. Effects of the invention

[0026] Some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery.

[0027] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery capable of appropriately determining whether there is a processing defect in the secondary battery.

[0028] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery that can be appropriately utilized for a cylindrical electrode assembly.

[0029] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery that can improve the reliability of test results.

[0030] However, the technical effects obtainable through the embodiments of the present disclosure are not necessarily limited to the effects mentioned above. Other technical effects not mentioned will be clearly understood by those skilled in the art to which the present disclosure pertains from other descriptions in the specification, such as the detailed description. Brief explanation of the drawing

[0031] Figure 1 is an example diagram showing an electrode assembly of a secondary battery. FIG. 2 is a schematic perspective view showing a test apparatus according to one embodiment of the present disclosure. Figure 3 is an unfolded view of the test device shown in Figure 2. Figure 4 is a plan view of the test apparatus shown in Figure 2. Figure 5 is a front view of the test apparatus shown in Figure 2. FIG. 6 is a schematic perspective view showing a test apparatus according to another embodiment of the present disclosure. Figure 7 is an unfolded view of the test device shown in Figure 6. FIG. 8 is a flowchart showing a test method according to one embodiment of the present disclosure. Figure 9 is a schematic diagram showing the state of the electrode assembly according to the pressurization step of Figure 8. Specific details for implementing the invention

[0032] Hereinafter, the present disclosure will be described in detail with reference to the attached drawings. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively.

[0033] The following embodiments are provided to more faithfully and completely explain the technical concept of the present disclosure to those skilled in the art to which the present disclosure pertains. Accordingly, the technical concept of the present disclosure is not necessarily limited to the following embodiments. The present disclosure should be understood to broadly include various equivalents, substitutions, modifications, etc., that embody the technical concept to be described below.

[0034] The terms used in the following description are intended to describe specific embodiments more faithfully and completely in the same light as above. Accordingly, the terms used in the following description should not be interpreted to reduce, limit, or restrict the technical scope of the present disclosure.

[0035] In the following description, terms such as "first," "second," etc., may be used to refer to specific components to distinguish them from other components. However, such terms are used for clarity of explanation, and the technical concept of the present disclosure should not be interpreted as being limited by such terms.

[0036] In the following description, singular expressions may be interpreted to include the plural unless explicitly excluded by the context. Furthermore, in the following description, the expression "includes" means that the components, parts, actions, features, steps, numbers, etc. described in the description exist, and does not exclude the addition of one or more other components, parts, actions, features, steps, numbers, etc.

[0037] In the following description, terms related to direction, such as "beneath," "above," "lower," and "upper," may be used to facilitate understanding of the components. However, such terms are provided to facilitate understanding of the present disclosure based on various operations and usage conditions, and should not be interpreted to reduce, limit, or restrict the technical scope of the present disclosure. For example, terms related to direction may be determined from a relative perspective.

[0038] Meanwhile, in the drawings below, the depiction of each component may be exaggerated or omitted for the convenience and clarity of explanation.

[0039] Figure 1 is an example diagram showing an electrode assembly of a secondary battery.

[0040] FIG. 1 illustrates one of the electrode assemblies (10) of a secondary battery. In some embodiments, the electrode assembly (10) may be provided in a cylindrical shape. Specifically, the electrode assembly (10) may be provided with a positive electrode (11) and a negative electrode (12) alternately arranged with a separator (13) in between, wound cylindrically around a central axis (C1). For reference, in the illustrated embodiment, the central axis (C1) is illustrated as an axis along the z-axis direction. Additionally, the separator (13), the positive electrode (11), and the negative electrode (12) are wound in a circumferential direction (P1) around the central axis (C1) to form a cylindrical electrode assembly (10).

[0041] In some embodiments, the secondary battery test device (hereinafter referred to as 'test device (100)') described below may be applied to a cylindrical electrode assembly (10) as illustrated. In other words, the test device (100) may be appropriately used to measure leakage current, etc., for the cylindrical electrode assembly (10). Additionally, the test device (100) may be configured to evenly press the outer surface (14) of the cylindrical electrode assembly (10) and to measure leakage current, etc., while the electrode assembly (10) is pressed in this manner. In some embodiments, such a test device (100) may function to more accurately identify whether there is a processing defect in the cylindrical electrode assembly (10). For example, the test device (100) may amplify the influence of foreign substances through appropriate pressure and measure leakage current, etc., in this state to more accurately identify whether there is a processing defect.

[0042] However, the application of the test device (100) is not necessarily limited to the cylindrical electrode assembly (10) as exemplified. The test device (100) may also be applied to electrode assemblies (10) of a shape different from that exemplified, within a scope that appropriately includes the technical concept to be described later.

[0043] Meanwhile, the cylindrical electrode assembly (10) may have a predetermined radius (R1) and height (H1) centered on a central axis (C1). In the illustrated embodiment, the radius (R1) of the electrode assembly (10) may refer to the length in the xy plane extending from the central axis (C1) to the outer surface (14) of the electrode assembly (10). Additionally, the height (H1) of the electrode assembly (10) may refer to the length of the electrode assembly (10) along the z-axis direction. In the present disclosure, the radius (R1) and height (H1) of the electrode assembly (10) to which the test device (100) is applied are not particularly limited. Furthermore, in some embodiments, the test device (100) may be configured to be applicable to electrode assemblies (10) having different specifications. In other words, the test device (100) can be configured to be compatible with each electrode assembly (10) having a radius (R1) and / or height (H1) that differs in some way. Such a test device (100) can contribute to improving ease of use or efficiency of equipment operation.

[0044] In some embodiments, the cylindrical electrode assembly (10) may have an outer surface (14). In the illustrated embodiment, the outer surface (14) may refer to the side circumference of the electrode assembly (10). The outer surface (14) may be formed to extend with a predetermined curvature around a central axis (C1).

[0045] FIG. 2 is a schematic perspective view showing a test apparatus according to one embodiment of the present disclosure.

[0046] Referring to FIG. 2, in some embodiments, a test device (100) may be provided. The test device (100) may be used to measure leakage current, etc. of an electrode assembly (10). In some embodiments, the test device (100) may include a pressure sheet (110) disposed on the outer surface (14) of the electrode assembly (10). Here, the pressure sheet (110) may be provided as a flexible sheet that wraps around the outer surface (14) and may be provided to press the outer surface (14) toward the central axis (C1) of the electrode assembly (10) while making surface contact with the outer surface (14) in close contact according to external forces (F1, F2) acting in the longitudinal direction.

[0047] Specifically, the pressure sheet (110) may be positioned to wrap around the outer surface (14) of the electrode assembly (10). In the illustrated embodiment, the pressure sheet (110) may form a roughly cylindrical mounting space (111), and the electrode assembly (10) may be positioned inside the mounting space (111).

[0048] In some embodiments, the pressure sheet (110) may be provided with a flexible material so as to wrap around the outer surface (14) of the electrode assembly (10). Additionally, the pressure sheet (110) may be provided as a sheet member having a predetermined thickness. The pressure sheet (110) provided with such a flexible sheet can function to uniformly press the outer surface (14) of the electrode assembly (10). Accordingly, when measuring leakage current, the influence of internal foreign matter, etc., can be appropriately amplified, and the presence of processing defects can be more clearly determined. Furthermore, the pressure sheet (110) provided with a flexible sheet can contribute to facilitating compatibility with the specifications of the electrode assembly (10). That is, the pressure sheet (110) provided with a flexible sheet can be relatively easily compatible with electrode assemblies (10) of various specifications.

[0049] In some embodiments, the pressure sheet (110) may comprise an electrically insulating material. That is, the pressure sheet (110) may be provided with an electrically insulating material in part or in whole so as to be electrically insulated from the electrode assembly (10). The electrically insulating material forming the pressure sheet (110) is not particularly limited as long as it has a certain flexibility and can be molded into a sheet shape. For example, the pressure sheet (110) may be provided with a synthetic resin material in part or in whole.

[0050] Meanwhile, in some embodiments, the pressure sheet (110) may be provided to apply pressure to the outer surface (14) of the electrode assembly (10). Specifically, an external force (F1, F2) may be applied to the pressure sheet (110). In the illustrated embodiment, the external force (F1, F2) may be applied to pull both longitudinal ends of the pressure sheet (110) in opposite directions. By doing so, the pressure sheet (110) may be in close contact with the outer surface (14) of the electrode assembly (10). Additionally, the pressure sheet (110) may be operated to apply pressure to the outer surface (14) of the electrode assembly (10) to a predetermined degree toward the central axis (C1). The test device (100) may be provided to measure leakage current, etc., while the electrode assembly (10) is in a state of being pressed in this manner.

[0051] FIG. 3 is an exploded view of the test apparatus shown in FIG. 2. FIG. 4 is a plan view of the test apparatus shown in FIG. 2. FIG. 5 is a front view of the test apparatus shown in FIG. 2.

[0052] Referring to FIGS. 3 to 5, in some embodiments, the pressure sheet (110) may have a first sheet region (112) and a second sheet region (113). The first sheet region (112) may be formed extending in the longitudinal direction (P2) from the first end (110a) of the pressure sheet (110). For reference, the longitudinal direction (P2) may refer to the direction in which the pressure sheet (110) is wound along the outer surface (14) of the electrode assembly (10). In the unfolded view of FIG. 3, the longitudinal direction (P2) corresponds to the x-axis direction. Additionally, the first end (110a) may refer to one end of the pressure sheet (110) along the longitudinal direction (P2). In the unfolded view of FIG. 3, the first end (110a) corresponds to the left end of the pressure sheet (110) along the x-axis direction.

[0053] The second sheet area (113) may be formed to extend in the longitudinal direction (P2) from the end of the first sheet area (112) to the second end (110b). The second end (110b) may refer to the opposite end corresponding to the first end (110a). In the unfolded view of FIG. 3, the second end (110b) corresponds to the right end of the pressure sheet (110) along the x-axis direction. In the unfolded view of FIG. 3, the second sheet area (113) may be formed to extend in the longitudinal direction (P2) from the right end of the first sheet area (112) to the second end (110b).

[0054] In some embodiments, the first and second sheet regions (112, 113) may be formed to extend to a sufficiently long length so as to completely wrap around the outer surface (14) of the electrode assembly (10). That is, the total length along the longitudinal direction (P2) of the first and second sheet regions (112, 113) may be formed to be sufficiently larger than the length along the outer surface (14) of the electrode assembly (10). Such first and second sheet regions (112, 113) may contribute to enabling the application of the test device (100) to electrode assemblies (10) of different specifications.

[0055] In some embodiments, the first sheet area (112) may be provided to have a first width (W1). For reference, the first width (W1) may refer to the width of the first sheet area (112) along a direction perpendicular to the longitudinal direction (P2). In the illustrated embodiment, the first width (W1) corresponds to the width of the first sheet area (112) along the z-axis direction. Meanwhile, the second sheet area (113) may be provided to have a second width (W2). The second width (W2) may refer to the width of the second sheet area (113) along a direction perpendicular to the longitudinal direction (P2), and in the illustrated embodiment, the second width (W2) corresponds to the width of the second sheet area (113) along the z-axis direction.

[0056] In the above, the second width (W2) may be provided to be smaller than the first width (W1). In other words, the second sheet area (113) may be provided with a width that is smaller than the first sheet area (112) by a predetermined amount. Additionally, the second width (W2) may be provided to be equal to the height (H1) of the electrode assembly (10) or larger than the height (H1) of the electrode assembly (10) by a predetermined amount. Such a second width (W2) can completely wrap the outer surface (14) of the electrode assembly (10) in the height direction and allow the pressure of the pressure sheet (110) to be applied evenly to the entire outer surface (14) of the electrode assembly (10). Furthermore, such a second width (W2) can enable the application of the test device (100) to electrode assemblies (10) of different specifications.

[0057] Meanwhile, in some embodiments, the first sheet area (112) may be provided with a slit (114). The slit (114) may be provided in a form in which the first sheet area (112) is partially cut. Additionally, the slit (114) may be positioned on one side of the longitudinal direction (P2) of the first sheet area (112) and extended in the width direction of the first sheet area (112). In the illustrated embodiment, the slit (114) is positioned adjacent to the left end of the first sheet area (112) along the x-axis direction and extended for a predetermined length along the z-axis direction.

[0058] The slit (114) can be connected to the second sheet area (113). That is, the second sheet area (113) can be connected such that the second end (110b) is inserted into the slit (114) and can be provided to be movable along the longitudinal direction (P2) while inserted into the slit (114). Through such movement of the second sheet area (113), the pressure sheet (110) can be provided to properly press the electrode assembly (10) placed in the mounting space (111). Meanwhile, for proper connection with the second sheet area (113), the width of the slit (114) may correspond to the second width (W2) or be provided to be a certain degree larger than the second width (W2).

[0059] In some embodiments, the first sheet area (112) may be divided into a first-1 sheet area (112a) and a first-2 sheet area (112b) centered around the slit (114). In FIG. 3, the first-1 sheet area (112a) corresponds to a portion of the first sheet area (112) positioned to the left of the slit (114), and the first-2 sheet area (112b) corresponds to the remaining portion of the first sheet area (112) positioned to the right of the slit (114). In some embodiments, at least a portion of the first-1 sheet area (112a) may be positioned spaced apart from the outer surface (14) of the electrode assembly (10) so that external forces (F1, F2) for testing are applied (see FIG. 4). Additionally, the first and second sheet regions (112b) may be positioned so that at least a portion thereof is in close contact with the outer surface (14) of the electrode assembly (10), thereby being configured to press the outer surface (14) toward the central axis (C1) (see FIG. 4).

[0060] Meanwhile, the pressure sheet (110) described above can be operated to press the outer surface (14) of the electrode assembly (10). In some embodiments, the pressure sheet (110) can be operated to press the outer surface (14) of the electrode assembly (10) by applying an external force (F1, F2) in the opposite direction to each end (110a, 110b). For example, in FIG. 4, an external force (F1) may be applied in the first direction (left direction) to the first end (110a) on the left, and an external force (F2) may be applied in the second direction (right direction) to the second end (110b) on the right. Accordingly, the pressure sheet (110) can be operated to press the outer surface (14) of the electrode assembly (10) as its inner diameter decreases.

[0061] In the above, the pressure sheet (110) can be operated to press the outer surface (14) of the electrode assembly (10) while making overall even contact with the outer surface (14) of the electrode assembly (10). That is, the pressure sheet (110) can be operated to press the outer surface (14) of the electrode assembly (10) evenly toward the central axis (C1) while making overall surface contact with the outer surface (14) of the electrode assembly (10). Accordingly, when measuring leakage current, etc. in a subsequent step, the influence of internal foreign substances, etc. can be appropriately amplified, and the defect status of the electrode assembly (10) can be more clearly determined.

[0062] In some embodiments, the external forces (F1, F2) applied to each end (110a, 110b) of the pressure sheet (110) may be provided with equal magnitude. Additionally, in some embodiments, either of the external forces (F1, F2) applied to each end (110a, 110b) of the pressure sheet (110) may be provided as a reaction force. For example, the pressure sheet (110) may be operated to press the electrode assembly (10) by fixing the first end (110a) and applying an external force (F2) to the second end (110b). Here, the external force (F1) applied to the first end (110a) may be provided as a reaction force due to the external force (F2) applied to the second end (110b).

[0063] Meanwhile, in some embodiments, the test device (100) may further include a measuring device (120). For reference, the measuring device (120) is briefly illustrated in FIG. 6 and is omitted for convenience in other drawings. The measuring device (120) may be configured to detect whether there is an insulation defect in the electrode assembly (10) while the pressure sheet (110) is appropriately pressing the outer surface (14). For example, the measuring device (120) may be configured to be connected to each electrode (11, 12) of the electrode assembly (10) to measure leakage current and / or insulation resistance. Additionally, the measuring device (120) may be configured to detect whether there is an insulation defect in the electrode assembly (10) by comparing the measured value with a preset reference value. In some embodiments, the measuring device (120) may include an ammeter, a voltmeter, etc.

[0064] FIG. 6 is a schematic perspective view showing a test apparatus according to another embodiment of the present disclosure. FIG. 7 is an exploded view of the test apparatus shown in FIG. 6.

[0065] For convenience, the following description will focus on the differences from the previously described embodiments.

[0066] Referring to FIGS. 6 and 7, in some embodiments, the pressure sheet (210) may be formed by dividing it into multiple parts. That is, the pressure sheet (210) may include at least one first pressure sheet (211) and at least one second pressure sheet (212). The illustrated embodiment illustrates a case in which two first pressure sheets (211) and two second pressure sheets (212) are provided. However, the number of first and second pressure sheets (211, 212) may increase or decrease as needed and is not necessarily limited to the example provided. For example, one first and second pressure sheet (211, 212) may be provided, or three or more may be provided. Additionally, depending on the case, the first and second pressure sheets (211, 212) may be provided in different numbers.

[0067] In some embodiments, the first pressure sheet (211) may be provided to wrap around the outer surface (14) of the electrode assembly (10) in a first rotational direction (P3). Here, the first rotational direction (P3) may refer to a rotational direction (P3) centered on the central axis (C1) of the electrode assembly (10). In the illustrated embodiment, the first rotational direction (P3) corresponds to a clockwise direction centered on the central axis (C1). The first pressure sheet (211) may be provided to wrap around a portion of the outer surface (14) in this manner. In the illustrated embodiment, two first pressure sheets (211) are provided such that the upper first pressure sheet (211) wraps around the upper portion of the outer surface (14), and the lower first pressure sheet (211) wraps around a portion of the central portion of the outer surface (14).

[0068] In some embodiments, the second pressure sheet (212) may be provided to wrap around the outer surface (14) of the electrode assembly (10) in a second rotational direction (P4). Here, the second rotational direction (P4) may be provided in the opposite direction to the first rotational direction (P3). That is, in the illustrated embodiment, the second rotational direction (P4) corresponds to a counterclockwise direction around the central axis (C1). The second pressure sheet (212) may be provided to wrap around the remaining area of ​​the outer surface (14) in this manner. In the illustrated embodiment, two second pressure sheets (212) are provided such that the upper second pressure sheet (212) wraps around the central remaining area of ​​the outer surface (14), and the lower second pressure sheet (212) wraps around the lower area of ​​the outer surface (14).

[0069] In some embodiments, the first and second pressure sheets (211, 212) described above may each be provided in multiple numbers, and the multiple first and second pressure sheets (211, 212) may be arranged alternately and repeatedly along the height direction of the electrode assembly (10). That is, describing with reference to the illustrated embodiment, the first pressure sheet (211) may be arranged in the upper region of the electrode assembly (10), the second pressure sheet (212) may be arranged below it, and the first pressure sheet (211) may be arranged again below it, so that the first and second pressure sheets (211, 212) may be arranged alternately and repeatedly. In some embodiments, the first and second pressure sheets (211, 212) may be provided in equal numbers.

[0070] In some embodiments, external forces (F1, F2) may be applied to the first pressure sheet (211) and the second pressure sheet (212) in different directions. Specifically, an external force (F2) may be applied to the first pressure sheet (211) in a direction corresponding to the first rotational direction (P3). That is, in the illustrated embodiment, the first pressure sheet (211) may be provided to wrap around the outer surface (14) of the electrode assembly (10) in a clockwise direction, and an external force (F2) may be applied to the end of the first pressure sheet (211) in the direction to the right in the drawing. Additionally, an external force (F1) may be applied to the second pressure sheet (212) in a direction corresponding to the second rotational direction (P4). That is, in the illustrated embodiment, the second pressure sheet (212) may be provided to wrap around the outer surface (14) of the electrode assembly (10) in a counterclockwise direction, and an external force (F1) may be applied to the end of the second pressure sheet (212) in the left direction in the drawing.

[0071] As described above, the first and second pressure sheets (211, 212) may each be provided to apply pressure to a portion of the outer surface (14) of the corresponding electrode assembly (10). Additionally, at least one set of such first and second pressure sheets (211, 212) may be combined so that the outer surface (14) of the electrode assembly (10) is pressed as a whole. For example, as illustrated, two sets of the first and second pressure sheets (211, 212) may be combined to apply pressure to the outer surface (14) of the electrode assembly (10) as a whole.

[0072] In some embodiments, the first and second pressure sheets (211, 212) may each have a predetermined width. For reference, in the illustrated embodiment, the width may refer to the width of the first and second pressure sheets (211, 212) along the z-axis direction. In some embodiments, the widths of the first and second pressure sheets (211, 212) may be formed to be the same. The first and second pressure sheets (211, 212) with the same width may apply a uniform external force to the entire outer surface (14) of the electrode assembly (10). Additionally, the first and second pressure sheets (211, 212) may be arranged adjacently in the width direction. That is, in the illustrated embodiment, the lower end of the first pressure sheet (211) along the z-axis direction may be arranged adjacently to the upper end of the second pressure sheet (212). In some embodiments, to reduce the area where no pressure is applied to the outer surface (14) of the electrode assembly (10), the spacing along the width direction of the first and second pressure sheets (211, 212) may be minimized.

[0073] Meanwhile, in some embodiments, the test device (100) may include a bracket (220) for supporting the first and second pressure sheets (211, 212) as described above. The first pressure sheet (211) may be supported such that a first end (211a) along the longitudinal direction is fixed to the bracket (220), and an external force (F2) for applying pressure to the electrode assembly (10) may be applied to the second end (211b) on the opposite side. Similarly, the second pressure sheet (212) may be supported such that a first end (212a) along the longitudinal direction is fixed to the bracket (220), and an external force (F1) for applying pressure to the electrode assembly (10) may be applied to the second end (212b) on the opposite side.

[0074] In some embodiments, the bracket (220) may be provided with a first slit (221) into which a second end (211b) of a first pressure sheet (211) is inserted and secured so as to be movable in the longitudinal direction. The first slit (221) may be formed through the bracket (220) having a predetermined width corresponding to the first pressure sheet (211). In some embodiments, a plurality of first slits (221) may be provided to correspond to the number of first pressure sheets (211). Similarly, the bracket (220) may be provided with a second slit (222) into which a second end (212b) of a second pressure sheet (212) is inserted and secured so as to be movable in the longitudinal direction. The second slit (222) may be formed through the bracket (220) having a predetermined width corresponding to the second pressure sheet (212), and in some embodiments, the second slit (222) may be provided in multiple numbers corresponding to the number of second pressure sheets (212).

[0075] In some embodiments, the bracket (220) may include an electrically insulating material. For example, the bracket (220) may be made of a synthetic resin material in part or in whole.

[0076] The first and second pressure sheets (211, 212) as described above can be operated to apply pressure to the outer surface (14) of the electrode assembly (10) in a manner similar to the previously described embodiment. That is, with the electrode assembly (10) placed in the mounting space, external forces (F1, F2) of different directions can be applied to the first and second pressure sheets (211, 212), respectively. Accordingly, the first and second pressure sheets (211, 212) can be operated to apply pressure to the electrode assembly (10) to a predetermined degree while adhering to the outer surface (14) of the electrode assembly (10). In addition, while the electrode assembly (10) is pressed in this manner, leakage current, etc., can be measured through a measuring device, and the insulation defect of the electrode assembly (10) can be inspected.

[0077] FIG. 8 is a flowchart showing a test method according to one embodiment of the present disclosure.

[0078] FIG. 8 illustrates a method for testing whether a secondary battery is defective using the test apparatus (100, 200) of the aforementioned embodiments. The illustrated test method can be performed similarly in the test apparatus (100) described with reference to FIG. 2, etc., or in the test apparatus (200) described with reference to FIG. 6, etc. For convenience, the test method will be described below with reference to the test apparatus (100) described with reference to FIG. 2, etc.

[0079] Referring to FIG. 8, in some embodiments, a test method for a secondary battery (hereinafter referred to as 'test method (S100)') may be provided. In some embodiments, the test method (S100) may include the step (S110) of placing a pressure sheet (110) provided as a flexible sheet on the outer surface (14) of an electrode assembly (10); the step (S120) of applying an external force to the pressure sheet (110) and pressing the outer surface (14) while the pressure sheet (110) makes surface contact with the outer surface (14) so ​​as to be in close contact with it; and the step (S130) of measuring one or more of the leakage current and insulation resistance of the electrode assembly (10) while in a pressured state.

[0080] Specifically, a pressure sheet (110) may first be placed on the outer surface (14) of the electrode assembly (10) (S110). Referring to FIG. 2 described above, the pressure sheet (110) is placed in a state forming a mounting space (111), and the electrode assembly (10) may be inserted into the mounting space (111). In some embodiments, to facilitate the smooth insertion of the electrode assembly (10), the pressure sheet (110) may be prepared in a state where the mounting space (111) is expanded to a certain degree. Additionally, as the electrode assembly (10) is inserted into the mounting space (111), the pressure sheet (110) may be placed adjacently on the outer surface (14) of the electrode assembly (10).

[0081] Next, external forces (F1, F2) may be applied to the pressure sheet (110) (S120). For example, as shown in FIG. 2 above, external forces (F1, F2) in opposite directions may be applied to the first and second ends (110a, 110b) of the pressure sheet (110). Accordingly, the pressure sheet (110) may press the outer surface (14) to a predetermined degree while approaching the outer surface (14) of the electrode assembly (10). Here, the pressure sheet (110) may press the outer surface (14) while making even surface contact with the entire outer surface (14) of the electrode assembly (10).

[0082] Figure 9 is a schematic diagram showing the state of the electrode assembly according to the pressurization step of Figure 8.

[0083] Referring to FIG. 9, the pressurization process of the electrode assembly (10) as described above enables the detection of foreign substances (Q1) remaining inside the electrode assembly (10) more reliably. For example, as illustrated, the foreign substances (Q1) remaining inside the electrode assembly (10) have limited influence on the electrode or separator before pressurization, but after pressurization, the influence on the electrode or separator is amplified, such as by causing damage to the electrode or separator, and can be properly detected through the measurement of leakage current or insulation resistance in the pressurized state. Accordingly, the test method (S100) can more clearly determine whether there is a processing defect in the secondary battery.

[0084] Referring again to FIG. 8, the leakage current or insulation resistance of the electrode assembly (10) can be measured (S130). As described above, the measurement of the leakage current, etc., can be performed while the electrode assembly (10) is under pressure, and accordingly, the presence of processing defects can be determined more clearly.

[0085] Meanwhile, in some embodiments, the test method (S100) may further include a step (S140) in which the electrode assembly (10) is separated again from the pressure sheet (110). Specifically, when the measurement step (S130) is completed, the external force (F1, F2) acting on the pressure sheet (110) may be released. Accordingly, the electrode assembly (10) may be provided in a state where the pressure exerted by the pressure sheet (110) is released and it can be separated from the pressure sheet (110). In some cases, to facilitate the smooth separation of the electrode assembly (10), the pressure sheet (110) may be moved a certain amount in the opposite direction of the external force (F1, F2) so that the mounting space (111) is expanded a certain amount. When the pressure is released in this way, the electrode assembly (10) can be separated from the pressure sheet (110). Additionally, another electrode assembly (10) may be introduced for testing.

[0086] As described above, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery.

[0087] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery capable of appropriately determining whether there is a processing defect in the secondary battery. In some embodiments, the test apparatus, etc., may be configured to apply pressure to the outer surface of an electrode assembly while making surface contact in close contact with the outer surface of the electrode assembly, and accordingly, leakage current, etc., may be measured in a state where the influence of internal foreign substances, etc., is appropriately amplified. Accordingly, the presence of a processing defect may be more clearly determined.

[0088] In addition, some embodiments of the present disclosure may provide a test apparatus and test method for a secondary battery that can be appropriately utilized for a cylindrical electrode assembly. In some embodiments, the pressure sheet may be provided as a flexible sheet and configured to apply pressure to the outer surface of the electrode assembly according to an external force applied in the longitudinal direction, and accordingly, the test apparatus, etc., can create an appropriate pressure state for the cylindrical electrode assembly and perform measurements such as leakage current. Furthermore, the pressure sheet provided as a flexible sheet can relatively easily accommodate various specifications of the electrode assembly, thereby contributing to improving the usability of the test apparatus, etc.

[0089] In addition, some embodiments of the present disclosure may provide a test apparatus and a test method for a secondary battery that can improve the reliability of test results. In some embodiments, a pressure sheet provided as a flexible sheet can evenly apply a constant pressure to the entire outer surface of an electrode assembly, and leakage current, etc., can be measured while the electrode assembly is subjected to such uniform pressure. Accordingly, the presence of internal foreign substances, etc., can be detected more clearly over the entire area of ​​the electrode assembly, and the reliability of the test results can be improved.

[0090] The above description is merely an example of applying the principles of the present disclosure, and other configurations may be included without departing from the scope of the present disclosure.

[0091] Although embodiments of the present disclosure have been described above, those skilled in the art may modify or change the present disclosure in various ways by adding, changing, deleting, or adding components without departing from the technical spirit of the present disclosure as described in the claims, and such modifications or changes shall also be deemed to be included within the scope of the rights of the present disclosure. Explanation of the symbols

[0092] 10: Electrode assembly 100: Test device (First embodiment) 110: Pressure sheet 120: Measuring device 200: Test device (2nd embodiment) 210: Pressure sheet 220: Bracket

Claims

Claim 1 A test device for a secondary battery, comprising a pressure sheet disposed on the outer surface of an electrode assembly, wherein the pressure sheet is provided as a flexible sheet that wraps around the outer surface and is configured to press the outer surface toward the central axis of the electrode assembly while making close surface contact with the outer surface according to an external force acting in the longitudinal direction. Claim 2 A test device for a secondary battery according to claim 1, wherein the electrode assembly is provided with a positive electrode and a negative electrode alternately arranged with a separator in between and wound cylindrically around the central axis. Claim 3 A test device for a secondary battery according to claim 1, comprising a measuring device configured to measure one or more of the leakage current and insulation resistance of the electrode assembly while the pressure sheet presses the outer surface. Claim 4 A test device for a secondary battery according to claim 1, wherein the pressure sheet comprises an electrically insulating material. Claim 5 A test apparatus for a secondary battery according to claim 1, wherein the pressure sheet comprises: a first sheet region extending longitudinally from a first end; and a second sheet region extending longitudinally from an end of the first sheet region to a second end corresponding to the first end. Claim 6 A test device for a secondary battery according to claim 5, wherein the first sheet region has a slit, and the second sheet region is inserted and fastened to be movably in the longitudinal direction into the slit. Claim 7 A test apparatus for a secondary battery according to claim 5, wherein the first sheet area is provided to have a first width, and the second sheet area is provided to have a second width smaller than the first width. Claim 8 A test device for a secondary battery according to claim 7, wherein the second width is formed to be equal to the height of the electrode assembly or to be larger than the height by a predetermined amount. Claim 9 A test device for a secondary battery according to claim 1, wherein the pressure sheet is configured to apply an external force in a first direction to a first end and an external force in a second direction opposite to the first direction to a second end corresponding to the first end, thereby applying pressure to the outer surface. Claim 10 A test apparatus for a secondary battery according to claim 1, wherein the pressure sheet comprises: a first pressure sheet provided to wrap around a portion of the outer surface in a first rotational direction; and a second pressure sheet provided to wrap around another portion of the outer surface in a second rotational direction opposite to the first rotational direction. Claim 11 A test apparatus for a secondary battery according to claim 10, wherein the first and second pressure sheets are each provided in a plurality, and the plurality of first and second pressure sheets are alternately and repeatedly arranged along the height direction of the electrode assembly. Claim 12 A test device for a secondary battery according to claim 10, wherein the first pressure sheet is provided to apply pressure to a part of the outer surface by applying an external force in a direction corresponding to the first rotational direction, and the second pressure sheet is provided to apply pressure to another part of the outer surface by applying an external force in a direction corresponding to the second rotational direction. Claim 13 A test device for a secondary battery according to claim 10, comprising a bracket in which each first end of the first and second pressure sheets is supported, wherein the bracket comprises: a first slit into which the second end of the first pressure sheet is inserted so as to be movable in the longitudinal direction; and a second slit into which the second end of the second pressure sheet is inserted so as to be movable in the longitudinal direction. Claim 14 A method for testing a secondary battery, comprising: a step of placing a pressure sheet, which is provided as a flexible sheet, on the outer surface of an electrode assembly; a step of applying an external force to the pressure sheet and pressing the outer surface while the pressure sheet comes into close contact with the outer surface; and a step of measuring one or more of the leakage current and insulation resistance of the electrode assembly in the pressured state. Claim 15 A test method for a secondary battery according to claim 14, comprising the step of releasing the external force and separating the electrode assembly from the pressure sheet when the measurement step is completed.

Images