Device for measuring physical properties of electrodes and / or separators

Abstract

According to one embodiment of the present disclosure, an apparatus for measuring an electrode and / or a separator of a secondary battery comprises: a container including a main body capable of accommodating a sample and an electrolyte therein; and a measurement unit for measuring the physical properties of the sample, in which the sample is at least one of an electrode and a separator for a secondary battery, and the measurement is performed in a state in which the sample is impregnated with an electrolyte.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims the benefits of Korean Patent Application No. 10-2023-0078300, filed on June 19, 2023, and Korean Patent Application No. 10-2024-0072521, filed on June 3, 2024, the entire disclosure of which is incorporated herein by reference.

[0003] This disclosure relates to an apparatus for measuring the physical properties of electrodes and / or separators, and more specifically, to an apparatus for measuring the physical properties of electrodes and / or separators used in a secondary battery while they are immersed in an electrolyte. Background Technology

[0004] A secondary battery is a rechargeable and dischargeable battery. Secondary batteries are widely used in portable small electronic devices such as mobile phones and laptops, or as power sources for motors in power tools, automobiles, and other applications. Internally, a secondary battery consists of a positive electrode, a negative electrode, a separator, and an electrolyte; its casing can be made of metal plates or bags.

[0005] According to existing technology, when measuring the physical properties of electrodes and / or separators under conditions such as stretching, compression, and stamping, the samples of electrodes and / or separators are tested in a dry state. However, for secondary batteries using liquid electrolytes, the electrodes and separators in actual secondary batteries are in a state of being immersed in the electrolyte. Therefore, the physical properties (mechanical behavior characteristics) of the secondary battery will change because the polymer (electrode adhesive, separator) is softened by the electrolyte, and the electrolyte penetrates (impregnates) into the pores of the electrodes and separator.

[0006] Therefore, in order to more accurately evaluate the manufacturing process or performance of secondary batteries, a technique is needed that can configure the state / environment of the electrodes and separators to approximate that of an actual secondary battery, thereby measuring the physical properties of the electrodes and / or separators. Summary of the Invention

[0007] Technical issues

[0008] The purpose of this disclosure is to provide an apparatus for measuring the physical properties of electrodes and / or separators used in a secondary battery while the electrodes and / or separators are immersed in an electrolyte.

[0009] However, the technical objectives of this disclosure are not limited to those described above, and can be extended in various ways within the scope of the technical ideas included in this disclosure.

[0010] Technical solution

[0011] According to one embodiment of this disclosure, a measuring device is provided, comprising: a container including a body capable of storing a sample and an electrolyte inside; and a measuring unit for measuring the physical properties of the sample, wherein the sample is at least one of an electrode and a separator for a secondary battery, and the measurement is performed while the sample is immersed in the electrolyte.

[0012] The container may include at least one of an electrolyte inlet located at the top and an electrolyte outlet located at the bottom.

[0013] The container may include an observation window through which the interior of the container can be observed.

[0014] The container also includes a door capable of opening and closing the main body, the door having an opening portion, and an observation window may be disposed in the opening portion.

[0015] The measuring device may also include a seal disposed between the body of the container and the door to prevent electrolyte leakage.

[0016] The measuring device may also include a locking device that secures the door to the body of the container when the door is closed.

[0017] The measuring device also includes a rod that passes through the upper surface of the container and is movable toward the sample or in the opposite direction, and is capable of stretching or pressurizing the sample by the movement of the rod.

[0018] The rod is provided with a pair of clamps at its end, which are capable of clamping the two ends of the sample respectively. One of the clamps is detachably connected to the end of the rod, and the other clamp is detachably connected to the lower inner surface of the body of the container.

[0019] The end of the rod is provided with a pressure fitting that is detachably connected thereto, and the lower inner surface of the container body is provided with a sample mounting component that is detachably connected thereto. The pressure fitting includes a tip, and the sample mounting component includes a sample mounting portion. The sample mounting portion has a recess at the center, and the center of the lower surface of the sample can be separated from the sample mounting portion.

[0020] The end of the rod is provided with a compression member that is detachably connected thereto, and the lower inner surface of the container body is provided with a sample mounting member that is detachably connected thereto. The compression member includes a flat-shaped compression portion, and the sample mounting member includes a sample mounting portion disposed at the lower end, and the sample mounting portion may have a flat shape.

[0021] The measuring unit may be a load sensor connected to the rod.

[0022] The rod moves downward, thereby measuring and converting the reaction force transmitted from the specimen to the rod by the load sensor, and then measuring the radial tensile force generated at the central portion of the specimen.

[0023] The measurement unit may be a camera unit.

[0024] The camera unit can be used to capture images of the sample in order to measure the displacement of the sample.

[0025] The camera unit may be a DIC (Digital Image Correlation) camera.

[0026] The measuring device further includes a calibration image for correcting errors that may occur in the image captured by the measuring unit due to the refraction or reflection of light by the electrolyte. The calibration image, serving as a reference image, comprises a plurality of line segments located on a substrate, each of which has the same length but a different slope. The measuring unit is calibrated by capturing the calibration image immersed in the electrolyte until all the line segments have the same length.

[0027] Each of the plurality of line segments may have an angle of inclination that increases sequentially with one edge of the substrate as a reference line.

[0028] At least some of the line segments can be arranged at approximately equal angles to each other.

[0029] The starting points of at least some of the multiple line segments may be different, and the ending points of at least some of the multiple line segments may be different.

[0030] The sample can be a stacked single cell composed of electrodes and a separator.

[0031] Beneficial effects

[0032] According to this disclosure, the apparatus measures the physical properties of the electrodes and / or separators of a secondary battery while the electrodes and / or separators are immersed in electrolyte. This allows for testing under conditions similar to those of actual battery use, thereby enabling a more accurate assessment of the physical properties of the electrodes and / or separators and / or battery cells.

[0033] The effects of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the detailed description of the appended claims other additional effects not described above. Attached Figure Description

[0034] Figure 1This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to an embodiment of the present disclosure; Figure 2 The diagram shows... Figure 1 The measuring device 100 contains electrolyte 20; Figure 3 yes Figure 1 A partial enlarged view of the side of the measuring device 100; Figure 4 The diagram shows the installation at Figure 1 Example of a sample 10 on a measuring device 100; Figure 5 The illustration shows that in Figure 1 The measuring device 100 is equipped with a camera unit 300 for photographing and measuring the sample 10; Figure 6 Shown in Figure 1 In the measuring device 100, during use Figure 5 Camera calibration image 310 used for calibration before the camera unit 300 performs measurements; Figure 7 This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to another embodiment of this disclosure; Figure 8 It shows in Figure 7 The measuring device 100 contains electrolyte 20; Figure 9 yes Figure 7 Enlarged view of the pressure fitting 220 and the sample mounting part 230; Figure 10 It shows the installation to Figure 7 Example of a sample 10 on a measuring device 100; Figure 11 This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to another embodiment of this disclosure; Figure 12 The illustration shows that in Figure 11 The measuring device 100 contains electrolyte 20; Figure 13 yes Figure 11 Enlarged view of the compression member 240 and the sample mounting member 250; Figure 14 yes Figure 13 A front view of the compression component 240; Figure 15 yes Figure 13 A top view of the sample mounting component 250; Figure 16 Showing installation to Figure 11Example of a sample 10 on a measuring device 100; Figure 17 A table showing a comparison between the negative electrode tested using a dry process according to a comparative example and the negative electrode tested using a wet process according to an embodiment of this disclosure; Figure 18 A table comparing the positive electrode tested using a dry process according to comparative examples with the positive electrode tested using a wet process according to embodiments of this disclosure is shown. Figure 19 A table comparing the diaphragm tests performed using a dry process according to comparative examples with the diaphragm tests performed using a wet process according to embodiments of this disclosure; Figure 20 Charts showing comparative examples and embodiments at the cell level are displayed; Figure 21 Showing Figure 20 The table shows the maximum load values ​​in the chart. Detailed Implementation

[0035] Various embodiments of this disclosure will now be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement it. This disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0036] For clarity of description, parts irrelevant to the description will be omitted, and throughout the specification, the same reference numerals designate the same elements.

[0037] Furthermore, in the accompanying drawings, for ease of description, the dimensions and thicknesses of the components are shown arbitrarily, and this disclosure is not necessarily limited to those shown in the drawings. In the accompanying drawings, for clarity, the thicknesses of layers, regions, etc., are exaggerated. In the accompanying drawings, for ease of description, the thicknesses of some layers and regions are exaggerated.

[0038] Additionally, it should be understood that when an element such as a layer, film, region, or plate is referred to as being "on" or "above" another element, it can be located directly on said other element, or there may be intermediate elements present. Conversely, when an element is referred to as being "directly located" on another element, it means that there are no other intermediate elements. Furthermore, the expression "on" or "above" means being arranged above or below a reference portion, and does not necessarily mean being arranged at the upper end of the reference portion in the opposite direction to gravity.

[0039] Furthermore, throughout the specification, when a section is described as "including" or "contains" a component, unless otherwise stated, this means that the section may also include other components, without excluding other components.

[0040] Furthermore, throughout the instruction manual, when "plane" is mentioned, it means viewing the target part from above, and when "section" is mentioned, it means viewing the target part from one side of a vertically cut section.

[0041] The various components of an apparatus for measuring the physical properties of electrodes and / or diaphragms according to an embodiment of the present disclosure, and the measurements (tests) performed by the corresponding measuring apparatus, will now be described with reference to the accompanying drawings.

[0042] Single axis tensile testing

[0043] first, Figures 1 to 6 The illustration shows a uniaxial tensile test performed using an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to an embodiment of the present disclosure.

[0044] Figure 1 This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to an embodiment of the present disclosure. Figure 2 The illustration shows that in Figure 1 The measuring device 100 contains electrolyte 20. Figure 3 yes Figure 1 A partial enlarged view of the side of the measuring device 100. Figure 4 The diagram shows the installation at Figure 1 An example of a sample 10 on a measuring device 100.

[0045] An apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to an embodiment of the present disclosure includes a container capable of storing a sample 10 and an electrolyte 20. The container includes: a body 110 (hereinafter referred to as the "container body") storing the sample 10 and electrolyte 20; a door 120 disposed on a surface (e.g., the front surface) of the container body and capable of being opened and closed; a rod 130 passing through the upper surface of the container body 110 and movable toward the sample 10 or in the opposite direction; an electrolyte inlet 140 disposed at the upper part of the container body 110; and an electrolyte outlet 150 disposed at the lower part of the container body 110.

[0046] Unlike existing technologies using dry processes, this disclosure uses a wet process and enables the measurement of the properties (physical properties, etc.) of the sample 10 while the sample 10 of the electrode and / or diaphragm is immersed in the electrolyte 20. The interior of the container body 110 can store not only the sample 10 but also the electrolyte 20. The container body 110 can be made of, for example, metal or PVC material, but this disclosure is not limited thereto. The container body 110 can also be made of a rigid material with low reactivity to the electrolyte solvent components.

[0047] When the sample 10 is stored in the container body 110, the door 120 is closed. The container body 110 and the door 120 are equipped with a locking device 170 (see details). Figure 3 The locking device securely fastens the container body 110 and the door 120 to each other. The door 120 is provided with an observation window 121 through which the interior of the container body 110 can be observed. Measurements can be taken while observing the storage state of the sample 10 and the electrolyte 20 through the observation window 121. An opening may be provided in the door 120, and the observation window 121 may be attached to the opening. A seal (not shown) may be further included around the opening to prevent leakage of the electrolyte 20. The observation window 121 may be made of, for example, a tempered glass material, but this disclosure is not limited thereto; the observation window 121 may be made of a material that is low in reactivity with the electrolyte solvent components, has rigidity, and allows the interior to be seen with the naked eye or a camera.

[0048] At the same time, this disclosure is not limited to what is shown in the figure, but can be modified and varied in various ways, such as the observation window 121 being located on the container body 110 instead of the door 120.

[0049] The electrolyte inlet 140 is provided in the upper part of the container body 110 in the shape of a through hole, and a pipe (not shown) for supplying electrolyte 20 through the electrolyte inlet 140 is connected to the interior of the container body 110 to supply electrolyte 20. The electrolyte outlet 150 is provided in the lower part of the container body 110 in the shape of a through hole. A pipe 151 and an on / off valve 152 are connected to the electrolyte outlet 150.

[0050] After the sample 10 is installed and the door 120 is closed, with the on / off valve 152 closed before measurement, the electrolyte 20 flows into the container body 110, allowing the sample 10 to be tested while the electrolyte 20 is contained inside the container body 110. In a wet test, after measurement, the on / off valve 152 can be opened to discharge the electrolyte 20 to the outside of the container body 110. Alternatively, even if a dry test is desired, the on / off valve 152 can be opened to discharge the electrolyte 20 to the outside of the container body 110 before testing.

[0051] The measuring device also includes a seal 160 located between the container body 110 and the door 120. This prevents the electrolyte 20 from leaking through the gap between the container body 110 and the door 120. Figure 1As shown, the seal 160 can be provided on the container body 110, but this disclosure is not limited to this, and various modifications can be made, for example, the seal 160 can be provided on the door 120.

[0052] The rod 130 is positioned to pass through the upper surface of the container body 110 and is movable toward the sample 10 or in the opposite direction. Various components for measurement are mounted at the end of the rod 130.

[0053] Figure 1 The embodiment describes a uniaxial tensile test performed on the specimen 10, wherein the end of the rod 130 is provided with a pair of clamps 210 capable of holding both ends of the specimen 10. One clamp of the pair of clamps 210 is detachably connected to the end of the rod 130, and the other clamp of the pair of clamps 210 is detachably connected to the lower surface inside the container body 110. The specimen 10 is mounted between the pair of clamps 210, and the rod 130 stretches the specimen 10 while moving it vertically from the lower part to the upper part of the container body 110. This is achieved by utilizing a camera unit described below (see...). Figure 5 ( ) to capture an image of the specimen 10, thereby allowing measurement of the displacement of the stretched specimen 10.

[0054] Figure 3 yes Figure 1 A partial enlarged view of the side of the measuring device 100. A small observation window 180 is also provided on the side of the container body 110 for checking whether the sample 10 is installed correctly, etc.

[0055] Figure 4 An embodiment of a specimen 10 provided for performing a uniaxial tensile test is shown. The specimen 10 can be, for example, made of… Figure 4 It is prepared as shown and installed between a pair of clamps 210.

[0056] To prevent the sample 10 from breaking prematurely, it can be... Figure 4 The method shown partially modifies the ASTM E345 standard specimen to prepare a shape with curvature (e.g., R19 mm, R10 mm). However, this disclosure is not limited to the form shown in the figures, but various modifications and variations can be made, such as by modifying the overall or partial dimensions of the specimen 10, or by preparing the specimen 10 into a strip or band for testing in the case of uniaxial tensile testing.

[0057] Figure 5 It shows in Figure 1 The measuring device 100 is equipped with a camera unit 300 for photographing and measuring the sample 10.Figure 6 Shown in Figure 1 In the measuring device 100, during use Figure 5 The camera correction image 310 is used for calibration before the camera unit 300 performs measurements.

[0058] In this configuration, the camera unit 300 corresponds to the measurement unit. The camera unit 300 is positioned in front of the container body 110. The camera unit 300 may be, for example, a DIC (Digital Image Correlation) camera, and it captures images of the sample 10 inside the container body 110 to measure the displacement of the sample 10. When the displacement data of the sample 10 transmitted from the camera unit 300 is input to a computer, the displacement value of the sample 10 is converted by the computer's processor into various physical values, such as the deformation rate.

[0059] In the case of wet testing, due to the refraction or reflection of light caused by the electrolyte 20, it may be difficult to measure the degree of deformation (e.g., deformation rate) of the specimen 10 within the required accuracy. Therefore, uniaxial tensile testing of the specimen 10 immersed in the electrolyte 20 can be performed using 2D-DIC (two-dimensional digital image correlation) measurement technology. In 2D-DIC measurement, the camera unit 300 and the specimen 10 are aligned along a straight line.

[0060] Before testing the sample 10, first use Figure 6 The correction image 310 in the image corrects the image captured by the camera unit 300 so that it has an actual, accurate length value, rather than a value with errors caused by the refraction or reflection of light due to the electrolyte 20. Figure 6 (a) is an example of the corrected image 310. Figure 6 (b) illustrates mounting the corrected image 310 to... Figure 1 The situation between a pair of clamps 210.

[0061] The correction image 310 is mounted to Figure 1 The camera 300 is positioned between a pair of clamps 210, and the corrected image 310 is arranged inside the container body 110. The container body 110 is filled with electrolyte 20. The position of the camera 300 is then adjusted until the length values ​​of all line segments placed in the corrected image 310, which serves as the reference image, are equal.

[0062] Figure 6The corrected image 310 is configured, for example, to arrange a plurality of line segments 312 on a square plate-shaped substrate 311. First, each of the plurality of line segments 312: 312-1, 312-2, 312-3 ... 312-k, 312-k+1 ... 312-n (where k is a natural number from 1 to n) has the same length. Furthermore, each of the plurality of line segments 312 has a different slope (the straight lines obtained by extending the plurality of line segments have different slopes).

[0063] More specifically, each of the plurality of line segments 312 may have an angle of inclination that increases sequentially with one edge of the base 311 as a reference line (e.g., a horizontal or vertical line). Figure 6 The example shows the tilt angle when using a horizontal line (-x axis) as a baseline.

[0064] At this time, for at least some of the multiple line segments 312, the difference in tilt angle between adjacent line segments can be equal. Figure 6 An example is shown below: the tilt angle of line segment 312-1 is 0 degrees, the tilt angle of line segment 312-2 is 15 degrees, the tilt angle of line segment 312-3 is 30 degrees, the tilt angle of line segment 312-k (k=4) is 45 degrees, and the tilt angle of line segment 312-k+1 (k=4) is 60 degrees, and these angles increase by 15 degrees in sequence.

[0065] In other words, at least some of the line segments 312 can be arranged at equal angles to each other. Therefore, arranging the line segments 312 (i.e., arranging them uniformly) such that the difference in tilt angle between adjacent line segments 312 is equal can help correct errors over a wider range, compared to arranging the line segments 312 densely within a certain range.

[0066] However, this disclosure is not limited to the above settings. If an error is likely to occur within a certain tilt angle range, the present invention can be modified and changed to arrange the line segments more densely within the specific tilt angle range.

[0067] Furthermore, at least some of the line segments 312 may have the same starting point, but they may also be as follows: Figure 6 The results are different. Similarly, at least some of the line segments 312 may have the same endpoint, but they may also be as shown. Figure 6 The results are different.

[0068] When all the starting points and ending points of the plurality of line segments 312 are different, image correction can be performed over a wider area. However, this disclosure is not limited thereto, and various variations and modifications can be made to implement it according to the environment in which it is applied.

[0069] By employing the correction image 310 according to this disclosure, the image captured by the camera unit 300 is unaffected by various angles of light incident on the electrolyte 20, thereby enabling accurate measurement of the length value (i.e., displacement value) of the sample 10.

[0070] Biaxial tensile test

[0071] Figures 7 to 10 This illustrates a biaxial tensile test performed in an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms, according to another embodiment of this disclosure.

[0072] Figure 7 This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to another embodiment of this disclosure. Figure 8 It shows in Figure 7 The measuring device 100 contains electrolyte 20. Figure 9 yes Figure 7 Enlarged view of the pressure fitting 220 and the sample mounting part 230. Figure 10 It shows the installation to Figure 7 The sample 10 on the measuring device 100.

[0073] Figures 7 to 10 The embodiments relate to biaxial tensile testing, wherein the main description will be related to the above. Figure 1 Different parts of the measuring device 100 related to the uniaxial tensile test described herein.

[0074] Regarding the aforementioned uniaxial tensile test, it has been described that the test is conducted along one axial direction ( Figure 1 In the embodiment, the container body 110 (in the height direction and the rod 130 in the length direction) directly pulls the specimen 10 to stretch the specimen 10. However, regarding Figures 7 to 10 The biaxial tensile test in this embodiment can be performed indirectly without directly pulling the specimen 10 in both axes. Measurement can be performed by applying pressure (punching) to the specimen with a tip and measuring and converting the reaction force of the specimen 10. In related technical fields, the term "press fitting" refers to applying pressure to the central portion of the specimen with a tip to generate radial tensile force, rather than striking or punching the specimen for a short period.

[0075] like Figure 10 As shown, the sample 10 is prepared into a thin film. Then, the sample is placed in a... Figures 7 to 9 The sample is mounted on the sample mounting piece 230, and pressure is applied to the central part of the upper surface of the sample 10 using the pressure fitting 220.

[0076] The pressure fitting 220 is detachably connected to the end of the rod 130, and the sample mounting member 230 is detachably connected to the lower surface of the interior of the container body 110. When in Figure 1 After completing the uniaxial tensile test described above in the embodiments, if it is desired to perform according to Figure 7 During the biaxial tensile test of the embodiment shown, a pair of clamps 210 can be detached from the rod 130 and the container body 110 respectively, and then the pressure fitting 220 and the sample mounting piece 230 can be installed.

[0077] The pressure fitting 220 includes a connecting portion 222 and a tip 221. The connecting portion 222 can be connected to the end of the rod 130, and the tip 221 is a pointed portion disposed at the end of the connecting portion 222. The sample mounting component 230 includes a main body 232 and a sample mounting portion 231. The main body 232 can be connected to the inner lower surface of the container body 110, and the sample mounting portion 231 is disposed at the upper central portion of the main body 232. The sample mounting portion 231 has a recess at its central portion. That is, the edge of the lower surface of the sample 10 contacts the edge of the sample mounting portion 231, and the central portion of the lower surface of the sample 10 is spaced apart from the sample mounting portion 231 by a predetermined distance and has a suspended structure.

[0078] The specimen 10 is placed on the specimen mounting portion 231, and the rod 130 moves downward to apply pressure to the central portion of the upper surface of the specimen 10 using the tip 221 of the pressure fitting 220. The tip 221 has a relatively sharp point shape, but it is not intended to immediately drill a hole in the specimen 10 when pressure is applied; instead, it generates a radial tensile force centered on the tip 221 that applies pressure to the specimen 10. Since the central portion of the lower surface of the specimen 10 is spaced a predetermined distance from the specimen mounting portion 231, the central portion of the specimen 10 warps downward along the pressure direction of the tip 221. At this time, a radial tensile force is generated from the tip 221 that applies pressure to the specimen 10, thereby enabling a biaxial tensile test. Furthermore, a reaction force is generated in the opposite direction to the direction in which the tip 221 applies pressure to the specimen 10 from above. Biaxial tensile testing is performed by measuring and converting the reaction force against the pressure applied using the tip 221, rather than directly measuring the radially generated tensile force (biaxial tensile force). A load sensor 400 is connected to the upper end of the rod 130. Therefore, the reaction force transmitted to the rod 130 can be measured. In this case, the load sensor 400 corresponds to the measuring unit.

[0079] The pressure fitting 220 may be made of, for example, Teflon material to reduce the effect of friction, but this disclosure is not limited thereto, and materials suitable for the environment in which the invention is implemented may be used.

[0080] Figures 7 to 10 The embodiments relate to biaxial tensile testing, wherein the methods described above are omitted. Figures 1 to 6 The description of the overlapping components of the measuring device 100 for uniaxial tensile testing described above. Please refer to the above description.

[0081] Compression test

[0082] Figures 11 to 16 The illustration shows a compression test being performed in an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to another embodiment of the present disclosure.

[0083] Figure 11 This is a front view of an apparatus 100 for measuring the physical properties of electrodes and / or diaphragms according to another embodiment of this disclosure. Figure 12 It shows in Figure 11 The measuring device 100 contains electrolyte 20. Figure 13 yes Figure 11 Enlarged view of the compression component 240 and the sample mounting component 250. Figure 14 yes Figure 13 The main view of the compressed component 240. Figure 15 yes Figure 13 A top view of the sample mounting component 250. Figure 16 Showing installation to Figure 11 An example of a sample 10 on a measuring device 100.

[0084] Figures 11 to 16 The embodiments relate to compression testing, wherein the main differences from the measuring apparatus 100 described above for uniaxial tensile testing and biaxial tensile testing will be described.

[0085] In Figures 11 to 16 In the embodiment related to the compression test, the sample 10 is placed on the sample mounting component 250, and the upper surface of the sample 10 is pressurized by the compression component 240.

[0086] The compression member 240 is detachably connected to the end of the rod 130, and the sample mounting member 250 is detachably connected to the lower surface of the interior of the container body 110. When in Figure 1 After completing the uniaxial tensile test as described in the embodiment, if it is desired to perform the compression test according to this embodiment, the pair of clamps 210 can be removed from the rod 130 and the container body 110 respectively, and then the compression member 240 and the sample mounting member 250 can be installed. Alternatively, when inFigure 7 After completing the biaxial tensile test in the embodiment, the compression member 220 and the sample mounting member 230 can be disassembled respectively, and then the compression member 240 and the sample mounting member 250 can be installed.

[0087] The compression member 240 includes: a connector 242 capable of being connected to the end of the rod 130; and a flat-shaped compression portion 241 disposed at the end of the connector 242.

[0088] Even in the presence of Figure 7 In the measuring apparatus 100 of the embodiment related to the biaxial tensile test shown, the specimen 10 is also pressurized by the pressure fitting 220 by moving the rod downwards, even when... Figure 11 In the measuring apparatus 100 of this embodiment related to the compression test, the sample 10 is also pressurized by the compression member 240 by moving the rod downwards. Figure 7 In the case of biaxial tensile testing, the tip 221 of the pressure fitting 220 has a relatively sharp tip shape (but the end is blunted by rounding or other means to prevent premature breakage of the sample), and the tip 221 applies pressure to the central portion of the sample 10 prepared into a thin film to generate radial tensile force, including biaxial force. However, due to Figure 11 The compression portion 241 of the compression member 240 has a flat shape, thus it can be used to compress the sample 10, which is prepared in, for example, a cylindrical shape with a certain volume (see...). Figure 16 The upper surface of the specimen 10 is subjected to overall pressure for compression testing. The specimen 10 used for compression testing can be prepared, for example, using a mold-making machine and a testing machine such as the Instron 5943, into the following form: Figure 16 The shape shown.

[0089] The sample mounting component 250 includes: a main body 252 capable of being connected to the lower inner surface of the container body 110; and a sample mounting portion 251 disposed on the main body 252. The upper surface of the sample mounting portion 251 also has a flat structure overall. That is, it is connected to... Figure 7 The specimen mounting portion 231 with a central recess in the biaxial tensile test embodiment shown is different.

[0090] The upper surface of the sample 10 is pressurized by the flat surface of the compression part 241, and correspondingly, the lower surface of the sample 10 is pressurized by the flat surface of the sample mounting part 251, thereby causing the sample 10 to be squeezed.

[0091] While the measuring apparatus 100 of the above embodiments of this disclosure can be used to test electrodes and / or separators, various changes and modifications can be made, such as enabling the testing of stacked single cells.

[0092] Next, comparative examples and embodiments of the present disclosure will be described in relation to each of the anode, cathode, and diaphragm. The comparative examples involve testing sample 10 using a dry process according to the prior art, without impregnation with electrolyte. The embodiments of the present disclosure are based on the above-described... Figures 1 to 16 The measurement device 100 is used to test the sample 10 by immersing it in electrolyte 20 for a predetermined time using a wet process.

[0093] anode

[0094] For uniaxial tensile testing, according to Figure 4 The specimen 10 is prepared as shown. For the biaxial tensile test, the specimen 10 is prepared as follows: Figure 10 The sheet shown is prepared as follows for compression testing: Figure 16 The sample 10 shown is prepared by drying an anodic active material slurry made of graphite material at 120 degrees Celsius in a cylindrical mold, to a density similar to that of an anodic active material slurry coated on a current collector. Furthermore, for wet processes, sample 10 is immersed in electrolyte 20 for at least 20 minutes before measurement.

[0095] Figure 17 A table comparing the anode testing using a dry process according to comparative examples with the anode testing using a wet process according to embodiments of this disclosure is displayed. Figure 17 In the figures, (a) and (b) are the results of uniaxial tensile tests, (c) and (d) are the results of biaxial tensile tests, and (e) is the result of compression tests.

[0096] Compared with the dry test used as a comparative example of the prior art, in the wet test of the embodiments of this disclosure, it can be seen that the tensile modulus of elasticity is reduced by about 70%, the tensile yield strength is reduced by 20% to 30%, and the compressive modulus of elasticity and yield strength are both reduced by about 60% to 70%. In other words, it can be seen that the strength decreases when the sample 10 is immersed in the electrolyte 20.

[0097] cathode

[0098] For uniaxial tensile testing, according to Figure 4 The specimen 10 is prepared as shown. For the biaxial tensile test, the specimen 10 is prepared as follows: Figure 10 The thin sheet shown is prepared for compression testing as follows: Figure 16 The sample 10 shown is prepared by drying the positive electrode active material slurry of NCM material at 120 degrees Celsius in a cylindrical mold, to a density similar to that of the cathode active material slurry coated on the current collector. Furthermore, for wet processes, sample 10 is immersed in electrolyte 20 for at least 20 minutes before measurement.

[0099] Figure 18 The table shown compares the testing of the cathode using a dry process according to the comparative example and the testing of the cathode using a wet process according to embodiments of this disclosure. Figure 18 In the diagram, (a) and (b) are the results of a uniaxial tensile test, (c) is the result of a biaxial tensile test, and (d) is the result of a compression test. For reference, for uniaxial tensile testing, MD is an abbreviation for machine direction and TD is an abbreviation for transverse direction.

[0100] Compared with the dry test, which is a comparative example of the prior art, the wet test of the embodiments of this disclosure shows that the tensile modulus is reduced by about 50% to 60%, the tensile yield strength is reduced by 20% to 30%, and both the compressive modulus and yield strength are reduced by about 70%. In other words, it can be seen that the strength decreases when the sample 10 is immersed in the electrolyte 20.

[0101] diaphragm

[0102] For uniaxial tensile testing, according to Figure 4 The specimen 10 is prepared as shown. For the biaxial tensile test, the specimen 10 is prepared as follows: Figure 10 The sheet shown. Polypropylene (PP) is used as the material for the diaphragm. Furthermore, for wet processes, the sample 10 is immersed in electrolyte 20 for at least 20 minutes before measurement begins.

[0103] Figure 19 The table shown compares the testing of the diaphragm using a dry process according to the comparative example and the testing of the diaphragm using a wet process according to embodiments of this disclosure. Figure 19 In the figures, (a) and (b) are the results of uniaxial tensile testing, and (c) is the result of biaxial tensile testing.

[0104] Figure 20 The graphs show comparative examples and embodiments at the cell level. Figure 21 Showing Figure 20 A table showing the maximum load values ​​in the graph.

[0105] The measurement is performed by pressing multiple electrode stacked samples using the press fitting 220. Figure 20 It is a graph showing the change of force as measured by a load sensor. Figure 21 The peak value is displayed in chart form. From Figure 21 (b) It can be seen that, for the wet test according to the embodiments of this disclosure, the maximum load error rate is approximately 11%, which is basically consistent with the simulation. From Figure 21 (c) It can be seen that the error rate for dry testing is approximately 90%.

[0106] Although the invention has been described in detail above with reference to preferred embodiments, the scope of this disclosure is not limited thereto. Those skilled in the art can make various modifications and improvements using the basic concepts of this disclosure as defined in the appended claims, and such modifications and improvements are also within the scope of this disclosure.

[0107] Explanation of reference numerals in the attached figures

[0108] 100: Measuring device

[0109] 110: Container body

[0110] 20: Door

[0111] 121: Observation Window

[0112] 130: pole

[0113] 140: Electrolyte injection port

[0114] 150: Electrolyte outlet

[0115] 160: Seals

[0116] 210: Clamp

[0117] 220: Press-fit parts

[0118] 230: Sample mounting components

[0119] 240: Compression component

[0120] 250: Sample mounting component

[0121] 300: Camera

[0122] 310: Correcting the image

[0123] 400: Load sensor

Claims

1. A measuring device comprising: a container including a main body capable of storing a test sample and an electrolyte inside; and a measuring unit for measuring a physical property of the test sample, wherein the test sample is at least one of an electrode and a separator for a secondary battery, and the measurement is performed in a state in which the test sample is impregnated with the electrolyte.

2. The measuring device of claim 1, wherein, The container includes at least one of an electrolyte injection inlet provided at an upper portion and an electrolyte discharge outlet provided at a lower portion.

3. The measuring device of claim 1, wherein, The container includes an observation window through which an inside of the container is observable.

4. The measuring device of claim 3, wherein, The container further includes a door capable of opening and closing the main body, the door includes an opening portion, and the observation window is provided in the opening portion. 5.The measuring device according to claim 4, further comprising a seal provided between the main body of the container and the door to prevent leakage of the electrolyte.

6. The measuring device of claim 4, wherein, The measuring device further includes a locking device that fixes the door to the main body of the container when the door is closed.

7. The measuring device of claim 1, wherein, The measuring device further includes a rod that passes through an upper surface of the container and is movable toward the test sample or an opposite direction thereof, and the test sample is capable of being stretched or pressurized by the movement of the rod.

8. The measuring device of claim 7, wherein, An end portion of the rod is provided with a pair of grippers capable of gripping both end portions of the test sample, respectively, wherein one gripper of the pair of grippers is detachably coupled to the end portion of the rod, and the other gripper of the pair of grippers is detachably coupled to an inner lower surface of the main body of the container. 9.The measuring device according to claim 7, wherein an end portion of the rod is provided with a press fitting that is detachably coupled to the end portion of the rod, an inner lower surface of the main body of the container is provided with a test sample mount that is detachably coupled to the inner lower surface of the main body of the container, the press fitting includes a tip, the test sample mount includes a test sample mounting portion provided with a recess at a central portion, and a central portion of a lower surface of the test sample is spaced apart from the test sample mounting portion.

10. The measuring device of claim 7, wherein, An end portion of the rod is provided with a compression member that is detachably coupled thereto, an inner lower surface of the main body of the container is provided with a test sample mount that is detachably coupled thereto, the compression member includes a compression portion having a flat shape, and the test sample mount includes a test sample mounting portion having a flat shape.

11. The measuring device of claim 7, wherein, The measuring unit is a load sensor connected to the rod.

12. The measuring device of claim 11, wherein, The rod is moved downward, thereby measuring and converting a reaction force transmitted from the test sample to the rod through the load sensor, and further measuring a tensile force radially generated at a central portion of the test sample.

13. The measuring device of claim 1, wherein, The measuring unit is a camera unit.

14. The measuring device of claim 13, wherein, An image of the test sample is photographed by the camera unit to measure a displacement of the test sample.

15. The measuring device of claim 13, wherein, The camera unit is a DIC (Digital Image Correlation) camera. 16.The measuring device according to claim 1, further comprising a correction image for correcting an error that can be generated in an image photographed by the measuring unit due to refraction or reflection of light by the electrolyte. wherein, The correction image as a reference image includes a plurality of line segments on a substrate, and each of the plurality of line segments has the same length but has a different slope, and wherein the correction image impregnated with the electrolyte is photographed by the measurement unit, thereby calibrating the measurement unit until the plurality of line segments have the same length.

17. The measuring device of claim 16, wherein, Each of the plurality of line segments has a tilt angle that increases sequentially with reference to one edge of the substrate as a reference line.

18. The measuring device of claim 17, wherein, At least some of the plurality of line segments are arranged at substantially equal angles to each other.

19. The measuring device of claim 16, wherein, At least some of the plurality of line segments have different starting points, and at least some of the plurality of line segments have different ending points.

20. The measuring device of claim 1, wherein, The test sample is a stacked single cell in which an electrode and a separator are stacked.

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