Swelling test apparatus capable of measuring size of battery module

Abstract

The present invention relates to a swelling test apparatus comprising: a chamber having an internal space for accommodating a battery module; a power supply unit for charging and discharging the battery module; a measurement unit for measuring a size change of the battery module; a frame unit on which the measurement unit is mounted; and a reception unit for receiving size information of the battery module measured by the measurement unit, wherein the measurement unit is disposed to face a side surface of the battery module disposed inside the chamber.

Description

Swelling test device capable of measuring the size of battery modules

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2024-0161731 filed November 14, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to a swelling test device capable of measuring the size of a battery module, and more specifically, to a swelling test device capable of measuring the size of a battery module capable of obtaining results in real time while conducting a swelling test in which the battery module is repeatedly charged and discharged.

[0003]

[0004] As carbon emission regulations are being tightened as an alternative to reduce greenhouse gases, the proportion of eco-friendly energy sources being selected is gradually increasing. Among these, lithium-ion batteries are being used as an energy source for various electronic devices due to their advantage of being reusable through repeated charging and discharging, unlike primary batteries that are discarded after a single use.

[0005] In particular, the application of lithium-ion batteries assembled into battery modules and battery packs is increasing in fields requiring high-output and high-capacity energy sources, such as electric vehicles.

[0006] Lithium-ion batteries may experience swelling, a phenomenon in which the volume expands due to the decomposition of the internal electrolyte and the generation of gas during repeated charging and discharging cycles. If this swelling is not controlled, it can cause structural deformation in battery modules containing multiple lithium-ion batteries, which can lead to reduced durability, performance degradation, and a shortened lifespan of the battery module.

[0007] In addition, the volume expansion of lithium secondary batteries can cause deformation of the battery module and lead to the explosion of the battery module.

[0008] To prevent such problems, a test is performed by repeatedly charging and discharging the battery module and measuring the voltage drop according to the number of charge-discharge cycles. This allows not only to measure the battery's lifespan but also to measure the degree of volume change of the battery module during the charge-discharge process.

[0009] Specifically, a method is used in which the battery module is removed from the battery charging / discharging chamber and its width is measured after performing a set number of charges and discharges within the chamber.

[0010] Therefore, there is a problem in that not only can the degree of expansion of the battery module be measured only after the set charge / discharge cycle is completed, but it is also difficult to verify the degree of expansion of the battery module at charge / discharge cycles lower than the set number of charge / discharge cycles.

[0011] Furthermore, since the swelling test and measurement processes are separated, it takes a long time to measure the degree of expansion of each battery module after various charge-discharge cycles, and changes in the size of the battery module cannot be verified at points other than specific charge-discharge cycles. Therefore, it is difficult to obtain accurate results because values ​​before or after specific charge-discharge cycles must be estimated using techniques such as linear interpolation.

[0012] In this regard, Patent Document 1 discloses a cylindrical battery measuring device that measures changes in the external shape of a cylindrical battery at various different angles using a laser while charging and discharging the cylindrical battery.

[0013] Patent Document 1 discloses a cylindrical battery measuring device comprising a housing equipped with a mounting part for mounting a cylindrical battery, a swelling test device, and a sensor device for measuring changes in the external shape of a cylindrical battery in real time while charging and discharging the cylindrical battery, but it does not provide a technology for measuring changes in the external shape of a battery module while charging and discharging it.

[0014] Patent Document 2 discloses a cell jig for measuring swelling of a battery cell and a method for measuring swelling of a battery cell using the same, which can easily measure swelling in the width direction of the battery cell by detecting volume changes in the width direction of the battery cell.

[0015] Patent Document 2 comprises a single battery cell placed on a plate and a guide bar secured by an elastic pressure member to a side wall placed adjacent to the battery cell, and measures the change in the width of the battery cell by detecting the movement or pressure of the guide bar due to the swelling phenomenon of the battery cell.

[0016] Patent Document 2 discloses a technology for detecting changes in the width direction of a single battery cell, but does not recognize a technology for measuring changes in the external shape in real time while charging and discharging a battery module.

[0017] Therefore, it is necessary to develop technology capable of obtaining battery module swelling test results in real time.

[0018] (Prior Art Literature)

[0019] (Patent Document 1) Korean Published Patent Application No. 2024-0097243 (June 27, 2024)

[0020] (Patent Document 2) Korean Published Patent Application No. 2021-0138883 (Nov. 22, 2021)

[0021]

[0022] The present invention aims to solve the above-mentioned problem by providing a swelling test device capable of measuring the size of a battery module, which allows the results to be verified in real time while charging and discharging the battery module and performing a swelling test.

[0023]

[0024] A swelling test device according to the present invention for achieving such an objective comprises a chamber having an internal space formed for accommodating a battery module, a power supply unit for charging and discharging the battery module, a measuring unit for measuring a change in the size of the battery module, a frame unit on which the measuring unit is mounted, and a receiving unit for receiving size information of the battery module measured by the measuring unit, wherein the measuring unit may be positioned to face the side of the battery module disposed inside the chamber.

[0025] In the swelling test device according to the present invention, the frame portion comprises a main frame located on two outer sides parallel to the electric direction of the battery module and having a central axis parallel to the electric direction of the battery module, vertical frames connected orthogonally to both ends of the main frame, and an upper frame connecting the vertical frames and maintaining its shape, and the measuring portion may be mounted on the main frame.

[0026] In the swelling test device according to the present invention, the measuring unit can move horizontally on the main frame.

[0027] In the swelling test device according to the present invention, the main frame is coupled to the vertical frame through a adjusting member and can move vertically along the vertical frame.

[0028] In the swelling test device according to the present invention, the measuring unit includes a first measuring unit and a second measuring unit disposed on each of two sides parallel to the electric field direction of the battery module, and each of the first measuring unit and the second measuring unit can transmit the result of measuring the size change of the battery module in real time to the receiving unit.

[0029] In the swelling test device according to the present invention, the measuring unit can discontinuously measure the distance between the battery module and the measuring unit at a plurality of points.

[0030] In the swelling test device according to the present invention, the measuring unit can continuously measure the distance between the battery module and the measuring unit while moving.

[0031] In the swelling test device according to the present invention, the measuring part may be a laser distance measuring device.

[0032] In the swelling test device according to the present invention, the vertical frame includes a mounting portion at the bottom, and the frame portion can be fixed to the bottom of the chamber through a fixing member fastened to the mounting portion.

[0033] In the swelling test device according to the present invention, the positive terminal and negative terminal of the battery module are connected to the power supply unit to proceed with charging and discharging, and the measuring unit can measure the change in the external shape of the battery module being charged and discharged in real time.

[0034] In the swelling test device according to the present invention, the measuring unit moves its position and measures the change in size of the battery module, while the distance between the measuring unit and the battery module can be maintained at a constant level.

[0035] In the swelling test device according to the present invention, the receiving unit can determine the degree of expansion of the battery module sidewall using the result measured by the measuring unit and calculate the change in size of the battery module.

[0036]

[0037] The present invention can also be provided in a form that combines various means for solving the above problem.

[0038]

[0039] The present invention allows for checking the size change of a battery module inside a chamber by performing a swelling test of the battery module and charging and discharging it at each time, or by setting a measurement cycle.

[0040] In this way, since the volume change of the battery module can be checked in real time even before the swelling test of the battery module is completed, more detailed and accurate results can be obtained.

[0041]

[0042] FIG. 1 is a perspective view of a swelling test device according to the present invention.

[0043] Figure 2 is a side view of Figure 1.

[0044] Fig. 3 is a front view of Fig. 1.

[0045] FIG. 4 is a perspective view of a part of a battery module showing the measurement positions of discontinuous measurement sections.

[0046] FIG. 5 is a perspective view of a part of a battery module showing the measurement positions of a continuous measurement section.

[0047] Figure 6 is a graph showing the change in battery module width according to the number of charge and discharge cycles in the embodiment.

[0048] Figure 7 is a graph showing the change in battery module width according to the number of charge and discharge cycles in the comparative example.

[0049]

[0050] Embodiments that enable a person skilled in the art to easily practice the present invention are described in detail below with reference to the attached drawings. In describing the operating principles of the embodiments of the present invention in detail, specific descriptions of related known functions or configurations are omitted if it is determined that such detailed descriptions may unnecessarily obscure the essence of the present invention.

[0051] The same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected with other elements in between. Furthermore, the inclusion of a certain component means that, unless specifically stated otherwise, it does not exclude other components but rather implies that additional components may be included.

[0052] Descriptions that specify components by limiting or adding them may be applied to all inventions unless specifically limited, and are not limited to descriptions of specific inventions.

[0053] Throughout the description of the invention and claims of this application, anything indicated in the singular includes cases where it is plural unless otherwise noted.

[0054] Throughout the description of the invention and the claims of the present invention, "or" includes "and" unless otherwise noted. Therefore, "comprising A or B" means all three of the above cases: including A, including B, or including both A and B.

[0055] The present invention is described in detail with reference to the drawings and embodiments.

[0056] FIG. 1 is a perspective view of a swelling test device according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a front view of FIG. 1.

[0057] Referring to FIGS. 1 to 3, the swelling test device according to the present invention comprises a chamber (100) having an internal space formed for accommodating a battery module (10), a power supply unit (200) for charging and discharging the battery module (10), a measuring unit (300) for measuring a change in size of the battery module (10), a frame unit (400) on which the measuring unit (300) is mounted, and a receiving unit (500) for receiving size information of the battery module (10) measured by the measuring unit (300), wherein the measuring unit (300) is positioned to face the side of the battery module (10) placed inside the chamber (100).

[0058] The battery module (10) has a positive terminal (11) and a negative terminal (12) located at one end in the electric direction and can contain a pouch-type battery cell, and the pouch-type battery cell is arranged to be stacked along the x-direction within the battery module (10). Therefore, since the pouch-type battery cell expands in the x-direction during the charging and discharging process, the volume expansion of the battery module (10) also becomes prominent in the x-direction. Accordingly, the first side (21) and the second side (22) of the battery module can be deformed convexly.

[0059] In a specific example, the positive terminal (11) and negative terminal (12) of the battery module (10) are connected to the power supply unit (200) to proceed with charging and discharging, and the measuring unit (300) can measure the external change of the battery module (10) being charged and discharged in real time.

[0060] For example, the measuring unit (300) may be a laser distance measuring device, and the degree of expansion of the battery module (10) can be inspected through the time it takes for a laser beam irradiated from the measuring unit (300) to reach the first side (21) and the second side (22) of the battery module (10).

[0061] The frame section (400) includes main frames (410) located on the outer side of each of the first side (21) and the second side (22), which are two sides parallel to the electric direction (y) of the battery module (10), and whose central axis is parallel to the electric direction (y) of the battery module (10), vertical frames (420) connected orthogonally to both ends of the main frames (410), and an upper frame (430) formed in a rectangular line shape that connects all the vertical frames (420) and maintains the shape. The measuring section (300) is mounted on the main frame (410).

[0062] The measuring unit (300) measures the degree of volume expansion of the first side (21) and the second side (22) of the battery module (10) while moving horizontally along the main frame (410) while mounted on the main frame (410). At this time, the measuring unit (300) can move in both directions along the main frame (410).

[0063] Additionally, the main frame (410) is connected to the vertical frame (420) through the adjustment member (411) and moves vertically along the vertical frame (420) in the z-direction.

[0064] The adjusting member (411) is mounted on the vertical frame (420), and the main frame (410) is coupled to the adjusting member (411). The main frame (410) moves in the z-direction depending on the position change of the adjusting member (411) as it moves along the vertical frame (420).

[0065] The movement of the measuring unit (300) on the main frame (410) and the movement of the adjusting member (411) on the vertical frame (420) can be precisely controlled by using a servo motor to pre-set the measurement position and / or path.

[0066] Referring to FIG. 2, the length (L2) of the upper frame (430) is configured to be longer than the length (L1) of the battery module (10), and the height (H2) of the vertical frame (420) is configured to be higher than the height (H1) of the battery module (10). That is, the measuring unit (300) is mounted on the main frame (410) and moves back and forth in the y direction, and due to the vertical movement of the main frame (410), the degree of expansion of the entire first side wall (21) and second side wall (22) can be measured.

[0067] The measuring unit (300) includes a first measuring unit (301) and a second measuring unit (302) positioned on each of the two sides parallel to the electric field direction (y) of the battery module (10), and each of the first measuring unit (301) and the second measuring unit (302) transmits the result of measuring the size change of the battery module (10) in real time to the receiving unit (500). The measuring unit (300) and the receiving unit (500) may be configured to enable wired communication or wireless communication.

[0068] The receiving unit (500) can determine the degree of expansion of the side wall of the battery module (10) using the result measured by the measuring unit (300) and calculate the change in size of the battery module (10).

[0069] In this way, since the change in volume of the battery module can be measured while charging and discharging the battery module, the change in volume of the battery module can be recorded throughout the entire charging and discharging process even before the set number of charge-discharge cycles is completed, and the results can be transmitted to a receiver so that an observer can verify them.

[0070] The present invention performs a swelling test by charging and discharging a battery module while the battery module is placed in a chamber (10) for charging and discharging the battery module, and verifies the volume expansion of the battery module. A measuring unit (300) moves its position to measure the change in size of the battery module (10). At this time, as shown in FIG. 3, the distance (D) between the measuring unit (300) and the battery module (10) must be maintained constant to increase the reliability of the result. Therefore, it is necessary to fix the position of the battery module (10) and the frame unit (400).

[0071] Accordingly, the vertical frame (420) includes a mounting portion (440) at the bottom, and the frame portion (440) can be fixed to the chamber bottom (110) through a fixing member (450) that is fastened to the mounting portion (440). Additionally, although not shown in the drawing, a protrusion or a side wall may be provided at the location where the battery module (10) is placed to fix the position of the battery module (10), or a separate mounting portion may be provided on the battery module itself and a separate fixing member may be fastened to the separate mounting portion to fix it to the chamber bottom (110).

[0072] FIG. 4 is a perspective view of a part of a battery module showing the measurement positions of discontinuous measurement sections.

[0073] Referring to FIG. 4, if the locations of a plurality of points (310) to be measured are specified in advance on the first side (21) of the battery module (10), the first measuring unit (301) can measure the distance between the battery module (10) and the first measuring unit (301) discontinuously at a plurality of points while moving along the main frame (410) and / or along the vertical frame (420).

[0074] In addition, the second measuring part (302), which is not shown in FIG. 4, can also measure the distance between the second side (22) of the battery module (10) and the second measuring part (302), thereby allowing the degree of expansion of each of the first side (21) and the second side (22) to be confirmed.

[0075] FIG. 5 is a perspective view of a part of a battery module showing the measurement positions of a continuous measurement section.

[0076] Referring to FIG. 5, in order to check the degree of expansion of the first side (21) of the battery module (10), the first measuring part (301) can continuously measure the distance between the battery module (10) and the first measuring part (301) while moving along the main frame (410) and / or along the vertical frame (420).

[0077] FIG. 5 illustrates the movement path of the measuring unit (301). The measuring unit (301) can scan the first surface (21) while moving along the movement path to check the degree of expansion of the first surface in three dimensions.

[0078] In addition, the second measuring unit (302), which is not shown in FIG. 5, can continuously measure the distance between the second side (22) of the battery module (10) and the second measuring unit (302) to scan the second surface (22) and check the degree of expansion of the second surface in three dimensions.

[0079]

[0080] The following description refers to embodiments of the present invention, but this is for the sake of easier understanding of the present invention and does not limit the scope of the present invention.

[0081]

[0082] <Example>

[0083] As illustrated in FIG. 1, a battery module is placed in the chamber of the swelling test device according to the present invention and the battery module is fixed to the bottom of the chamber. A frame part is placed to surround the battery module, and a fixing member is inserted into the mounting part to fix the frame part to the bottom of the chamber.

[0084] Connect the power supply to the positive and negative terminals of the battery module, fix the position of the measurement unit, and proceed with charging and discharging up to 800 cycles.

[0085] The measuring unit measured the distance to the side wall of the battery module every 10 cycles while fixed in a constant position.

[0086] The measured results were transmitted wirelessly to the receiver.

[0087] Figure 6 is a graph showing the change in battery module width according to the number of charge and discharge cycles in the embodiment.

[0088] Referring to Fig. 6, results can be obtained by measuring the change in width of the battery module at intervals of 10 cycles during the process from the start of charging and discharging up to 800 cycles.

[0089]

[0090] <Comparative Example>

[0091] First, measure the width of the battery module using a vernier caliper.

[0092] Place the battery module in the chamber where the swelling test is performed, and connect the power supply to the positive and negative terminals of the battery module. After performing 200 cycles of charge and discharge, remove the battery module from the chamber and measure the width of the battery module using a vernier caliper.

[0093] Place the battery module back into the chamber and perform an additional 200 charge-discharge cycles for a total of 400 cycles. Remove the battery module from the chamber and measure the width of the battery module using a vernier caliper.

[0094] Place the battery module back into the chamber and perform an additional 200 charge-discharge cycles for a total of 600 cycles. Remove the battery module from the chamber and measure the width of the battery module using a vernier caliper.

[0095] Place the battery module back into the chamber and perform an additional 200 charge-discharge cycles for a total of 800 cycles. Remove the battery module from the chamber and measure the width of the battery module using a vernier caliper.

[0096] Figure 7 is a graph showing the change in battery module width according to the number of charge and discharge cycles in the comparative example.

[0097] Referring to Fig. 7, the results of 200, 400, 600, and 800 charge-discharge cycles are shown discretely, and the change in width of the battery module in other charge-discharge cycles was derived by linear interpolation.

[0098] Therefore, when measuring the volume expansion of a battery module as in the example, there is an advantage in being able to check the degree of expansion of the battery module at each charge / discharge cycle or according to a set period, regardless of the number of charge / discharge cycles.

[0099] As a result, the development process can be carried out more efficiently, and effective decision-making can be made.

[0100]

[0101] A person skilled in the art to which the present invention pertains would be able to perform various applications and modifications within the scope of the present invention based on the above content.

[0102]

[0103] (Explanation of symbols)

[0104] 10: Battery module

[0105] 11: Polar Terminal

[0106] 12: Negative terminal

[0107] 21: First side

[0108] 22: Second side

[0109] 100: Chamber

[0110] 110: Chamber bottom

[0111] 200: Power supply

[0112] 300: Measurement section

[0113] 301: First measuring section

[0114] 302: Second measuring unit

[0115] 310: Points

[0116] 400: Frame section

[0117] 410: Mainframe

[0118] 411: Adjustment member

[0119] 420: Vertical frame

[0120] 430: Upper frame

[0121] 440: Mounting section

[0122] 450: Fixing member

[0123] 500: Receiver

Claims

1. A chamber having an internal space formed to accommodate a battery module; A power supply unit for charging and discharging the above battery module; A measuring unit for measuring the size change of the above battery module; A frame portion on which the above-mentioned measuring unit is mounted; and A receiving unit that receives size information of a battery module measured by the above measuring unit; Includes, The above measuring unit is a swelling test device positioned to face the side of the battery module placed inside the chamber.

2. In Paragraph 1, The above frame part is, A main frame located on two outer sides parallel to the electric direction of the battery module, with a central axis parallel to the electric direction of the battery module; Vertical frames connected orthogonally to both ends of the main frame; and An upper frame that connects the above vertical frames and maintains the shape; Includes, The above measuring unit is a swelling test device mounted on the main frame.

3. In Paragraph 2, The above measuring unit is a swelling test device that moves horizontally on the mainframe.

4. In Paragraph 3, The above main frame is coupled to the vertical frame through an adjustment member, and the swelling test device moves vertically along the vertical frame.

5. In Paragraph 1, The above measuring unit includes a first measuring unit and a second measuring unit disposed on each of two sides parallel to the electric field direction of the battery module, and The swelling test device, wherein each of the first and second measuring units transmits the result of measuring the size change of the battery module to the receiving unit in real time.

6. In Paragraph 3, The above-mentioned measuring unit is a swelling test device that discontinuously measures the distance between the battery module and the measuring unit at multiple points.

7. In Paragraph 3, The above-mentioned measuring unit is a swelling test device that continuously measures the distance between the battery module and the measuring unit while moving.

8. In Paragraph 1, The above measuring unit is a swelling test device that is a laser distance measuring device.

9. In Paragraph 2, The above vertical frame includes a mounting part at the bottom, and A swelling test device in which the frame portion is fixed to the bottom of the chamber through a fixing member fastened to the mounting portion.

10. In Paragraph 1, The positive terminal and negative terminal of the above battery module are connected to the above power supply unit so that charging and discharging proceed, and The above measuring unit is a swelling test device that measures changes in the external shape of the battery module being charged and discharged in real time.

11. In Paragraph 1, A swelling test device in which the measuring unit moves to measure the size change of the battery module, while maintaining a constant distance between the measuring unit and the battery module.

12. In Paragraph 1, The above-described receiving unit determines the degree of expansion of the battery module sidewall using the result measured by the above-described measuring unit, and the swelling test device calculates the change in size of the battery module.

Images