Detection device and operating method for detecting electrode defects

Abstract

A detection device for detecting a faulty electrode according to various embodiments includes a measurement module configured to obtain thickness measurements of at least one electrode, and a processor electrically connected to the measurement module, wherein the processor may be configured to identify a depression formed in the at least one electrode based on the thickness measurements, and detect the at least one electrode as a faulty electrode when a wavy depression corresponding to a reference shape is identified.

Description

Technical Field

[0001] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2022-0134436 filed on October 18, 2022, and incorporates all the contents disclosed in the literature of the Korean patent application as part of this specification.

[0002] Various embodiments disclosed in this document relate to a detection device for detecting a defective electrode and an operating method thereof, and more particularly, to a technique for detecting a defective electrode that can cause the formation of a gap on the bonding surface with a separator.

Background Art

[0003] Secondary batteries have been increasing in development and use in recent years due to the advantages of being rechargeable, small in size, and large in capacity.

[0004] Such secondary batteries are manufactured in a form in which an electrode assembly composed of a cathode, a separator, and an anode is housed in a battery case together with an electrolyte. For example, the electrode assembly is manufactured by laminating the cathode and the anode with a separator interposed therebetween and then applying a predetermined level of heat and pressure. Here, the portion where the electrode and the separator face each other may be housed inside the battery case in a state of being bonded (e.g., adhered) to each other by heat and pressure.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, the bonding state between the electrode and the separator membrane in an electrode assembly is related to the performance of a secondary battery. For example, if the thickness of the portion where the electrode and the separator membrane face each other (e.g., the bonding surface) is uniform, the performance of the secondary battery is guaranteed to a predetermined level. Conversely, if the thickness of at least a portion of the portion where the electrode and the separator membrane face each other is not uniform due to reasons such as weakened adhesive strength, the performance of the secondary battery is not guaranteed to a predetermined level. As an example, in a portion where the thickness of the bonding surface is not uniform, high resistance can increase the consumption of the electrolyte, causing swelling of the battery cell and a decrease in the performance of the secondary battery due to lithium deposition.

[0006] At least one of the various embodiments of the present invention provides a detection device and a method of operating the same for detecting a defective electrode that may cause a decrease in the performance of a secondary battery.

[0007] At least one of the various embodiments of the present invention provides a detection device and a method of operating the same for detecting a defective electrode that may result in the formation of a gap (e.g., space) within an electrode assembly based on a change in electrode thickness. [Means for solving the problem]

[0008] A detection device for detecting a defective electrode according to various embodiments includes a measuring module configured to acquire a thickness measurement of at least one electrode, and a processor electrically connected to the measuring module, wherein the processor may be configured to check for a recess formed in the at least one electrode based on the thickness measurement, and to detect the at least one electrode as a defective electrode if a wavy recess corresponding to a reference shape is confirmed.

[0009] According to various embodiments, the processor may be configured to detect the wavy depression in a form in which a plateau area that increases to a predetermined level or more from the reference thickness of at least one electrode and a dip area that decreases to a predetermined level from the reference thickness are continuous.

[0010] According to various embodiments, the reference shape may include at least one of a specified area and a specified depth.

[0011] According to various embodiments, the processor may be configured to detect the recess in a sloped portion formed on the at least one electrode, where the thickness gradually decreases.

[0012] According to various embodiments, the inclined portion may be formed in a cutting step or a coating step among the manufacturing steps of the at least one electrode.

[0013] According to various embodiments, the processor may be configured to detect the recess in a predetermined range of the upper end of the electrode, oriented toward the other end with respect to the end of the electrode tab formed on at least one electrode.

[0014] According to various embodiments, the processor may be configured to obtain a thickness measurement of an electrode assembly in which a positive electrode and a negative electrode having substantially the same size are stacked with a separator film in between.

[0015] According to various embodiments, the processor may be configured to obtain a thickness measurement of an electrode assembly in which a relatively large negative electrode and a relatively small positive electrode are stacked with a separator film in between.

[0016] According to various embodiments, the processor may be configured to, upon detection of a wavy recess corresponding to the reference shape, check the distance between the position where the sinking region begins after the protruding region and the end of the positive electrode, detect at least one electrode as a normal electrode if the distance falls within a specified range, and detect at least one electrode as a faulty electrode if the distance falls outside the specified range.

[0017] According to various embodiments, the detection device may further include a memory, and the processor may be configured to reset the reference shape based on the shape of a wavy recess formed in the faulty electrode, and to store the reset reference shape in the memory.

[0018] The operation method of the detection device according to various embodiments may include the operation of acquiring a thickness measurement value of at least one electrode, the operation of confirming a recess formed in the at least one electrode based on the thickness measurement value, and the operation of detecting the at least one electrode as a defective electrode when a wavy recess corresponding to a reference shape is confirmed.

[0019] According to various embodiments, the wavy depression may include a configuration in which a plateau area, which increases to a predetermined level or more from the reference thickness of at least one electrode, and a dip area, which decreases to a predetermined level from the reference thickness, are continuous.

[0020] According to various embodiments, the reference shape may include at least one of a specified area and a specified depth.

[0021] According to various embodiments, the operation method may include the operation of checking the recess in a sloped portion formed on the at least one electrode, where the thickness gradually decreases.

[0022] According to various embodiments, the inclined portion may be formed in a cutting step or a coating step among the manufacturing steps of the at least one electrode.

[0023] According to various embodiments, the operation method may include checking the recess in a predetermined range of the upper end of the electrode, oriented toward the other end with respect to the end of the electrode tab formed on at least one electrode.

[0024] According to various embodiments, the operation method may include an operation of obtaining a thickness measurement value of an electrode assembly in which a positive electrode and a negative electrode having substantially the same size are stacked via a separator membrane.

[0025] According to various embodiments, the operation method may include an operation of obtaining a thickness measurement value of an electrode assembly in which a relatively large negative electrode and a relatively small positive electrode are stacked via a separator membrane.

[0026] According to various embodiments, when a wavy depression corresponding to the reference shape is confirmed, the operation method may include an operation of confirming the distance between the position where the sinking region starts after the protruding region and the end of the positive electrode, an operation of detecting the at least one electrode as a normal electrode when the distance is included in a specified range, and an operation of detecting the at least one electrode as a defective electrode when the distance is out of the specified range.

[0027] According to various embodiments, the operation method may include an operation of resetting the reference shape based on the shape of the wavy depression formed in the defective electrode and an operation of saving the reset reference shape.

Advantages of the Invention

[0028] A detection device for detecting electrode defects and its operation method according to various embodiments disclosed in this document enable the manufacture of a secondary battery in which a predetermined level of performance is guaranteed by detecting defective electrodes that can cause the formation of a gap in the electrode assembly based on changes in the thickness of the electrodes.

[0029] The effects obtained from this document are not limited to the effects mentioned above.

Brief Description of the Drawings

[0030] [Figure 1a] A diagram schematically showing a secondary battery according to various embodiments. [Figure 1b] A diagram schematically showing a secondary battery according to various embodiments. [Figure 1c] This diagram schematically illustrates secondary batteries according to various embodiments. [Figure 2] This figure shows the configuration of a detection device for detecting electrode defects according to various embodiments. [Figure 3a] This diagram illustrates a defective electrode that causes gap formation within the electrode assembly. [Figure 3b] This diagram illustrates a defective electrode that causes gap formation within the electrode assembly. [Figure 4a] This diagram illustrates the operation of detecting defective electrodes according to various embodiments. [Figure 4b] This diagram illustrates the operation of detecting defective electrodes according to various embodiments. [Figure 4c] This diagram illustrates the operation of detecting defective electrodes according to various embodiments. [Figure 4d] This diagram illustrates the operation of detecting defective electrodes according to various embodiments. [Figure 5] This diagram illustrates other operations for detecting faulty electrodes according to various embodiments. [Figure 6a] This diagram illustrates the performance of detection devices according to various embodiments. [Figure 6b] This diagram illustrates the performance of detection devices according to various embodiments. [Figure 7] This is a flowchart illustrating the operation of the detection device according to various embodiments. [Figure 8] This is a flowchart illustrating other operations of the detection device according to various embodiments. [Figure 9a] This diagram illustrates the operation of setting the criteria for determining the quality of electrodes in a detection device according to various embodiments. [Figure 9b] This diagram illustrates the operation of setting the criteria for determining the quality of electrodes in a detection device according to various embodiments. [Modes for carrying out the invention]

[0031] Hereinafter, some embodiments of the present invention will be described in detail with reference to illustrative drawings. When assigning reference numerals to components in each drawing, care should be taken to assign the same reference numeral to the same component whenever possible, even if it is shown in different drawings. Furthermore, when describing embodiments of the present invention, if a specific description of a related known configuration or function is deemed to hinder the understanding of the embodiments of the present invention, such detailed description will be omitted.

[0032] In describing the components of embodiments of the present invention, terms such as First, Second, A, B, (a), (b), etc., may be used. These terms are merely for distinguishing a component from other components, and do not limit the essence, order, or procedure of that component. Furthermore, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined herein.

[0033] The various embodiments and terminology used in this document should be understood not to limit the technical features described herein to any particular embodiment, but to include various modifications, equivalents, or substitutes of such embodiments. In relation to the description of the drawings, similar or related components may be given similar reference numerals. The singular form of the noun corresponding to an item may include one or more such items unless the context clearly indicates otherwise. In this document, each of the phrases such as "A or B," "A and B or at least one of A or B," "A, B or C," "A, B and C or at least one of A, B or C," etc., may include any one of the items listed together in the phrase, or any possible combination thereof. Terms such as "first," "second," "first," "second," etc., may be used simply to distinguish the component in question from other components in question, and should not limit the component in question in any other respect (e.g., importance or procedure). When one component (e.g., component 1) is referred to as being "coupled" or "connected" to another component (e.g., component 2), with or without the terms "functionally" or "communically," it means that component is connected to the other component directly (e.g., by wire or wirelessly) or via component 3.

[0034] Figures 1a to 1c are schematic diagrams illustrating secondary batteries according to various embodiments.

[0035] Referring to Figures 1a to 1c, the secondary battery 100 according to various embodiments may be configured in a form in which an electrode assembly 120 and an electrolyte are housed within a battery case 110.

[0036] According to various embodiments, the battery case 110 may include a first case 112 (e.g., an upper case) and a second case 114 (e.g., a lower case). The first case 112 may have a space configured to accommodate at least a portion of the electrode assembly 120, and the second case 114 may have a space configured to accommodate the other portion of the electrode assembly 120.

[0037] According to one embodiment, the electrode assembly 120 and the electrolyte may be housed in an internal space formed by the joining of the first case 112 and the second case 114, and the edges of the first case 112 and the edges of the second case 114 may be sealed while the electrode assembly 120 and the electrolyte are housed inside.

[0038] According to various embodiments, the electrode assembly 120 may be configured in which a first electrode 122 (e.g., anode or negative electrode plate) and a second electrode 125 (e.g., cathode or positive electrode plate) are stacked with a separator 121 in between.

[0039] According to one embodiment, each electrode 122, 125 may be formed in a structure in which an active material slurry is coated onto a current collector. For example, the slurry may be formed by stirring a mixture of granular active material, auxiliary conductor, binder, plasticizer, etc., with a solvent added.

[0040] According to one embodiment, each electrode 122, 125 may have a plain area where slurry is not applied, and electrode tabs 123, 126 corresponding to each electrode 122, 125 may be attached to such plain areas. Furthermore, one end of electrode leads 124, 127 may be attached to and connected to each electrode tab 123, 126, and the other ends of electrode leads 124, 127 may be exposed to the outside of the battery case 110 and provided as electrode terminals that can be connected to other secondary batteries, loads, charging devices, or other external devices.

[0041] According to various embodiments, each electrode 122, 125 and the separator membrane 121 can maintain a bonded state (e.g., bonded) within the electrode assembly 120 by heat and pressure. In order to ensure that the performance of the secondary battery 100 is guaranteed to a predetermined level, each electrode 122, 125 and the separator membrane 121 must be bonded such that a bonded surface (e.g., bonded surface) with a uniform thickness is formed. For example, in areas where the thickness of the bonded surface is not uniform, the consumption of the electrolyte within the electrode assembly 120 increases, which can cause swelling of the battery cells and a decrease in the performance of the secondary battery 100 due to lithium deposition.

[0042] In connection therewith, various embodiments described in detail with reference to the following drawings can detect at least one electrode 122, 125 that results in a non-uniform thickness bond with the separation membrane 121. Thus, it is possible to detect the electrodes 122, 125 that result in a non-uniform thickness bond with the separation membrane 121 before or after manufacturing the electrode assembly 120, thereby enabling the manufacture of a secondary battery 100 that guarantees a predetermined level of performance.

[0043] Detection devices for detecting defects in electrodes 122 and 125 according to various embodiments will be described in detail with reference to Figures 2 to 6 below.

[0044] Figure 2 shows the configuration of a detection device for detecting electrode defects according to various embodiments. Figures 3a and 3b illustrate a defective electrode that causes gap formation within the electrode assembly, Figures 4a to 4d illustrate the operation of detecting a defective electrode according to various embodiments, and Figure 5 illustrates another operation of detecting a defective electrode according to various embodiments.

[0045] Referring to Figure 2, various embodiments of the detection device 200 may consist of a measurement module 202, a memory 204, an output module 206, and a processor 208. However, these are merely examples, and the various embodiments are not limited thereto. For example, at least one of the components of the detection device 200 described above may be omitted, or one or more other components (e.g., an input device, a power management device, etc.) may be added to the configuration of the detection device 200. Also, at least one of the components described above may be integrated with the other components.

[0046] According to various embodiments, the measurement module 202 may be configured to acquire thickness measurements of at least one electrode 122, 125. According to one embodiment, the measurement module 202 can measure thickness measurements of at least one electrode 122, 125 coupled to the separation membrane 121. For example, the measurement module 202 may include a light-emitting unit configured to emit light toward at least one electrode 122, 125 and a light-receiving unit configured to detect light reflected from at least one electrode 122, 125.

[0047] According to various embodiments, the memory 204 may include programs, algorithms, routines and / or instructions relating to the operation (or control) of the detection device 200.

[0048] For example, memory 204 may include memory such as flash memory type, hard disk type, micro type, and card type (e.g., SD card (Secure Digital Card) or XD card (eXtream Digital Card)), and at least one type of storage medium from among RAM (Random Access Memory), SRAM (Static RAM), ROM (Read-Only Memory), PROM (Programmable ROM), EEPROM (Electrically Erasable PROM), magnetic memory (MRAM), magnetic disk, and optical disk, and various embodiments are not limited thereto.

[0049] According to various embodiments, the output module 206 can provide information regarding the operation of the detection device 200. For example, at least a portion of the information output by the output module 206 may include detection results for at least one electrode 122, 125 (e.g., a faulty electrode) that results in a non-uniform thickness coupling with the separation membrane 121.

[0050] According to one embodiment, the output module 206 may include a display configured to output visual information. For example, the display may include one or more of the following: a liquid crystal display, a thin-film transistor-liquid crystal display, an organic light-emitting diode, a flexible display, a 3D display, and a transparent display. The display may also include a touch sensor configured to detect touches.

[0051] However, this is merely illustrative, and various embodiments are not limited thereto. For example, at least some of the information regarding the operation of the detection device 200 can also be provided as auditory information. In that case, the output module 206 may further include an acoustic output device (e.g., a speaker) configured to output an acoustic signal to the outside of the detection device 200.

[0052] According to various embodiments, the processor 208 can control at least one other component of the detection device 200 (e.g., a measurement module 202, a memory 204, and an output module 206) and perform various data processing or calculations.

[0053] For example, the processor 208 can detect at least one electrode 122, 125 that results in a non-uniform thickness bond with the separator membrane 121. As mentioned above, if the thickness of the bond surface formed by the bonding of at least one electrode 122, 125 with the separator membrane 121 is not uniform, the performance of the secondary battery 100 may deteriorate.

[0054] The thickness of such a bonding surface may be determined by the morphology of at least one of the electrodes 122, 125. For example, referring to Figures 3a and 3b, when at least one electrode 122, 125 having a relatively submerged region (e.g., a recess) 310 formed on it is bonded to the separation membrane 121, it results in the formation of a gap (e.g., space) 320 of a predetermined size at the point where the at least one electrode 122, 125 and the separation membrane 121 face each other (e.g., the bonding surface). In one embodiment, the recess 310 may be a wavy recess, as shown in Figure 4a, in which a region 402 (e.g., a plateau area) that increases above a predetermined level from a reference thickness 401 (e.g., average thickness) on the surface of the electrodes 122, 125 is successively formed from a region 404 (e.g., a dip area) that decreases below a predetermined level from a reference thickness 401. The gap 320 formed by such a wavy recess 310 is a portion where at least a part of the electrodes 122 and 125 and at least a part of the separation membrane 121 are not bonded due to the weakened bonding force (e.g., adhesive force) around the recess 310 formed on the electrodes 122 and 125, which can result in the creation of a bonding surface with an uneven thickness.

[0055] In connection therewith, the processor 208 can detect at least one electrode 122, 125 having a recess 310 (e.g., a wavy recess) as a defective electrode that causes the formation of a gap 320 within the electrode assembly 120 when coupled with the separator membrane 120. Thus, it is possible to prevent the manufacture of electrode assemblies 120 having defective electrodes, and as a result, it becomes possible to manufacture a secondary battery 100 that guarantees a predetermined level of performance. Various embodiments of the processor 208 related thereto will be described in detail below.

[0056] According to various embodiments, the processor 208 can detect a change in the thickness of at least one electrode 122, 125 as part of an operation to detect a faulty electrode. For example, the processor 208 can measure the thickness (e.g., change in thickness) of at least one electrode 122, 125 based on measurements obtained by the measurement module 202.

[0057] According to various embodiments, the processor 208 can determine, based on the measured thickness, whether a recess 310 has been formed relative to the surrounding area for at least one electrode 122, 125. Preferably, the processor 208 can determine, based on a reference thickness 401 (e.g., average thickness) of the surface of the electrodes 122, 125, whether a wavy recess has been formed, comprising a region 402 (e.g., a protruding region) that increases above a predetermined level from the reference thickness 401 and a region 404 (e.g., a recessed region) that decreases below a predetermined level from the reference thickness 401.

[0058] According to one embodiment, the processor 208 can determine that a recess 310 is not formed on at least one electrode 122, 125 if its thickness changes in the same direction (or the same sign).

[0059] According to another embodiment, the processor 208 can determine that at least one recess 310 is formed in at least one electrode 122, 125 if there is an inflection point where the direction of change in the thickness of that electrode changes.

[0060] According to various embodiments, once it is confirmed that a recess 310 is formed in at least one electrode 122, 125, the processor 208 can determine whether the confirmed recess 310 can result in the formation of a gap 320 within the electrode assembly 120 when the at least one electrode 122, 125 is coupled to the separator membrane 120. For example, the processor 208 can determine that a recess 310 having a specified size and / or specified depth formed in at least one electrode 122, 125 can result in the formation of a gap 320.

[0061] According to one embodiment, as shown in Figure 4a, the processor 208 can determine the depth of the recess 310 based on the difference 420 between the maximum value 422 corresponding to the highest thickness of the object being measured (e.g., the highest thickness of the protruding region) and the minimum value 424 corresponding to the lowest thickness of the object being measured (e.g., the lowest thickness of the sinking region) among the measurement values ​​410 acquired by the measurement module 202. The processor 208 can also determine the size of the recess 310 based on a range in which measurement values ​​corresponding to a thickness below a predetermined level are continuous. However, this is merely illustrative, and various embodiments are not limited thereto. For example, various known techniques can be applied to determine the size and / or depth of the recess 310 formed in at least one electrode 122, 125.

[0062] The aforementioned at least one electrode 122, 125 can be defined as a main body portion and an upper end portion. The upper end portion can be defined as a predetermined range of region that faces in the direction of the other end of the electrode 122, 125 (e.g., the end of the electrode tabs 123, 126). The main body portion can be defined as the remaining region of the electrode 122, 125 excluding the upper end portion. Generally, the recess 310 that results in the formation of a gap 320 within the electrode assembly 120 is relatively more likely to occur at the upper end portion of the electrode 122, 125 than at the main body portion.

[0063] In connection with this, in various embodiments, the processor 208 can limit the determination region for determining whether or not a recess 310 is formed to the upper ends of the electrodes 122 and 125.

[0064] According to one embodiment, the electrode assembly 120 may be configured in a form in which a negative electrode 122 and a positive electrode 125 having substantially the same size are stacked with a separator membrane 121 in between, as shown in Figure 4b. In that case, the processor 208 can limit the upper end portion 430 of a predetermined range (d) facing the other end direction with respect to the end portion 431 of the electrode tabs 123 and 126 to the determination region. In other words, the processor 208 can omit the operation of determining whether or not a recess 310 is formed in the main body portions of the electrodes 122 and 125 excluding the determination region. However, this is merely an example, and various embodiments are not limited thereto. For example, the operation of determining whether or not a recess 310 is formed may be performed only in the main body portions of the electrodes 122 and 125, or it may be performed in the upper end portion and the entire main body portion.

[0065] In another embodiment, the electrode assembly 120 may be configured such that a negative electrode 122 and a positive electrode 125 of different sizes are stacked with a separator membrane 121 in place, as shown in Figure 4c. In this case, the processor 208 can limit the determination region to the upper end 440 where the two electrodes 122 and 125 do not face each other. That is, the processor 208 can determine whether or not a recess 310 is formed only with respect to a determination region (A+B) which includes region A from the end 122-1 of the relatively larger first electrode (e.g., negative electrode 122) to the end 123-1 of the electrode tab 123, and region B between the end 122-1 of the first electrode and the relatively smaller second electrode 125 to the end 125-1.

[0066] In various embodiments, inclined portions may be formed on the upper ends of electrodes 122 and 125. For example, in the cutting process, the ends of electrodes 122 and 125 (e.g., end 122-1 of the first electrode 122) may not be cut at a substantially right angle, and an inclined portion may be formed where the thickness gradually decreases towards the ends of electrodes 122 and 125. In another example, in the coating process, an inclined portion may be formed where the thickness of the slurry decreases towards the ends of electrodes 122 and 125.

[0067] Therefore, the processor 208 can define a range for obtaining the maximum value corresponding to the highest thickness of the object being measured, and a range for obtaining the minimum value corresponding to the lowest thickness of the object being measured, with the inclined portion as the reference point.

[0068] According to one embodiment, as shown in Figure 4d, the processor 208 defines the boundary 452 of the main body and upper end of the electrodes 122 and 125 (e.g., the end 125-1 of the second electrode 125 shown in Figure 4c) as the decision start point, and defines a predetermined range from the decision start point as the maximum value calculation range 454 (e.g., the protruding region detection range). For example, the maximum value calculation range 454 may be in the range of 2 mm to 5 mm from the decision start point. Preferably, the maximum value calculation range may be within 3 mm from the decision start point.

[0069] According to one embodiment, the processor 208 can define a predetermined range from the point 456 where the maximum value is calculated as the minimum value calculation range 458 (e.g., the subsidence area detection range). For example, the minimum value calculation range 458 may be in the range of 8 mm to 15 mm from the maximum value calculation point 456. Preferably, the minimum value calculation range may be within 10 mm from the maximum value calculation point 456.

[0070] According to various embodiments, the processor 208 can detect a faulty electrode based on a recess 310 formed within the electrodes 122, 125, as described above.

[0071] Additionally or selectively, the processor 208 may further consider the location of the recess 310 in detecting a faulty electrode. For example, the closer the location of the recess 310 is to the boundary 452 between the body and upper end of electrodes 122, 125 (e.g., the end 125-1 of the second electrode 125 shown in Figure 4c), the smaller the gap 320 will be formed. In this regard, as shown in Figure 5, the processor 208 can determine an electrode with a recess 310 formed therein, which can result in the formation of a gap 320 within the electrode assembly 120, to be a normal electrode if the distance 514 between the boundary 510 between the body and upper end of electrodes 122, 125 (e.g., the end 125-1 of the second electrode 125 shown in Figure 4c) and the location of the recess 512 falls within a specified range.

[0072] According to one embodiment, the processor 208 can determine the distance 514 between the end of the protruding region, that is, the portion 512 where the sinking region begins, and the boundary 510 between the main body and the upper end. For example, the portion 512 where the sinking region begins can be defined as being within 5% of the depth of the sinking region. For example, as shown in Figure 5, the distance 514 between the portion 512 where the sinking region begins and the boundary 510 between the main body and the upper end can also be defined as the width of the protruding region. In other words, an electrode in which a sinking region is formed continuously with a protruding region having a width within a specified range can be determined to be a normal electrode. Conversely, an electrode in which a sinking region is formed continuously with a protruding region having a width exceeding a specified range can be determined to be a defective electrode.

[0073] Figures 6a and 6b are diagrams illustrating the performance of detection devices according to various embodiments.

[0074] Referring to Figures 6a and 6b, it can be seen that a gap 320 can be formed within the electrode assembly 120 by at least one electrode 122, 125.

[0075] Specifically, Figure 6a shows the relationship between the shape of the target electrode and the gap.

[0076] For example, the third target electrode (case 3) 605 refers to a reference electrode that serves as the criterion for determining whether it is good or bad. The morphology of the first target electrode (case 1) 601 can be confirmed to be a morphology in which the thickness gradually decreases with a similar rate of decrease as that of the third target electrode 605. This means that the thickness 611 of the first target electrode 601, which does not have an inflection point where the direction of the thickness change changes, similar to the thickness change 615 of the third target electrode 605, can be detected as the thickness of a normal electrode that does not cause gap formation.

[0077] In contrast, it can be confirmed that the morphology of the second target electrode (case 2) 603 is such that its thickness decreases by a different amount than that of the third target electrode 605. This means that, unlike the change in thickness 615 of the third target electrode 605, the thickness 613 of the second target electrode 603, where there is an inflection point where the direction of the thickness change changes, can be detected as the thickness of a defective electrode that leads to the formation of a gap.

[0078] Figure 6b shows the electrode assembly 120 manufactured using the target electrode, demonstrating the high accuracy of the detection results shown in Figure 6a.

[0079] Specifically, Figure 6b(a) shows an electrode assembly 120 manufactured using the first target electrode 601, which was detected as a normal electrode, and it can be confirmed that a relatively small gap of size 620 is formed between the first target electrode 601 and the separation membrane 121.

[0080] In comparison, Figure 6b(b) shows an electrode assembly 120 manufactured using the second target electrode 603 which was detected as a defective electrode, and it can be confirmed that a relatively large gap of size 630 is formed between the second target electrode 603 and the separation membrane 121.

[0081] As described above, the detection device 200 according to various embodiments can accurately detect defective electrodes that may cause gap formation within the electrode assembly 120 based on changes in the thickness of electrodes 122 and 125.

[0082] The operation methods of the detection device according to various embodiments will be described in detail below with reference to Figures 7 to 9b.

[0083] Figure 7 is a flowchart illustrating the detection operation of a detection device according to various embodiments. The operations in the following embodiments may be performed sequentially, but are not necessarily required. For example, the order of the operations may be changed, and at least two operations may be performed in parallel. Furthermore, at least one of the following operations may be omitted depending on the embodiment.

[0084] Referring to Figure 7, the detection device 200 (e.g., processor 208) can measure the thickness of the negative electrode 122 coupled to the positive electrode 125 during operation 710. According to one embodiment, as shown in Figure 4c, the detection device 200 can measure the thickness of the negative electrode 122 when the relatively large negative electrode 122 and the relatively small positive electrode 125 are stacked with a separator membrane 121 in between.

[0085] According to various embodiments, the detection device 200 (e.g., processor 208) can determine, in operation 720, whether or not a gap 320 is formed in the coupling region based on the measured thickness. According to one embodiment, the detection device 200 can determine whether or not the negative electrode 122 is in a form that results in the formation of a gap 320. For example, the detection device 200 can determine whether or not a recess 310 having a specified depth and / or size is formed based on a change in the thickness of the negative electrode 122. For example, the detection device 200 can determine whether or not a wavy recess is formed, with a reference thickness 401 (e.g., average thickness) of the surface of electrodes 122, 125 as the reference thickness, in which a region 402 (e.g., protruding region) that increases above a predetermined level from the reference thickness 401 and a region 404 (e.g., subsided region) that decreases below a predetermined level from the reference thickness 401 are continuous.

[0086] According to various embodiments, the detection device 200 (e.g., processor 208) can determine in operation 730 that the negative electrode 122 is defective based on the determination result of the formation of the gap 320. According to one embodiment, the detection device 200 can determine that a negative electrode 122 in which a recess 310 having a specified depth and / or size is formed is a defective negative electrode.

[0087] Figure 8 is a flowchart illustrating other operations of the detection device according to various embodiments. The operations in Figure 8 described below may represent various embodiments relating to operation 730 in Figure 7.

[0088] Referring to Figure 8, various embodiments of the detection device 200 (e.g., processor 208) can determine the position of the recess 310 formed on the negative electrode 122 during operation 810.

[0089] According to various embodiments, the detection device 200 (e.g., processor 208) can determine in operation 820 whether the position of the recess 310 is within a predetermined distance with respect to the end of the positive electrode 125.

[0090] According to various embodiments, if the location of the recess 310 is within a predetermined distance from the end of the positive electrode 125, the detection device 200 (e.g., processor 208) can determine in operation 830 that the negative electrode 122 on which the recess 310 is formed is a normal negative electrode.

[0091] According to various embodiments, if the location of the recess 310 is not within a predetermined distance from the end of the positive electrode 125, the detection device 200 (e.g., processor 208) can determine in operation 840 that the negative electrode 122 on which the recess 310 is formed is a faulty negative electrode.

[0092] Figures 9a and 9b illustrate the operation of setting the criteria for determining the quality of electrodes in a detection device according to various embodiments.

[0093] Referring to Figures 9a and 9b, the detection device 200 according to various embodiments can set criteria for determining whether an electrode 122 or 125 is good or bad based on the results of the good or bad judgment (or analysis results).

[0094] According to various embodiments, the detection device 200 can store the results of the pass / fail judgment for electrodes 122 and 125 in the form of a table. For example, the detection device 200 can store the shape of the recess 310 formed on electrodes 122 and 125 that are judged to be normal. The shape of the recess 310 may include at least one of the formation location of the recess 310, the area of ​​the recess 310, and the depth of the recess 310. For example, if a wavy recess 310 is formed on electrodes 122 and 125, the detection device 200 can store the shape of the plateau area and the shape of the dip area.

[0095] According to various embodiments, the detection device 200 can set an approximate value (910) of the stored recess shape as a criterion for determining normality. For example, as shown in Figure 9b, a range (920) of recesses 310 to be determined to be normal can be specified based on the recess shape observed in a normal electrode. Such a criterion may be updated each time a good / bad judgment operation is performed. Thus, the detection device 200 can determine electrodes with recesses 310 that fall within the specified range as normal electrodes, and electrodes with recesses 310 that do not fall within the specified range as defective electrodes.

[0096] As described above, the detection device 200 according to various embodiments can set a standard for determining normality based on the results of the normality determination for electrodes 122 and 125. However, this is merely an example, and the various embodiments are not limited to this. For example, the detection device 200 according to various embodiments can also save the shape of the indentation 310 formed on the electrodes 122 and 125 that have been determined to be defective, and set an approximate value of the saved shape of the indentation 310 as a standard for determining defects.

[0097] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs could make various modifications and alterations without departing from the essential characteristics of the present invention.

[0098] Therefore, the embodiments disclosed herein are for illustrative purposes only, and not to limit the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention should be interpreted in accordance with the appended claims, and all technical concepts within an equivalent scope should be interpreted as being included within the scope of the present invention. [Explanation of Symbols]

[0099] 100 Secondary battery 110 Battery Case 112 Case 1 114 Case 2 120 Electrode assembly 121 Separation membrane 122, 125 electrode 122-1 End 123, 126 Electrode Tabs 123-1 End 124, 127 electrode leads 125-1 End 200 detection device 202 Measurement Module 204 memory 206 Output Module 208 processors 310 Dent 320 Gap

Claims

1. In a detection device for detecting defective electrodes, A measurement module configured to acquire thickness measurements of at least one electrode, The measurement module includes a processor electrically connected to it, The aforementioned processor, Based on the thickness measurement, the recess formed in the at least one electrode is confirmed. A detection device configured to detect a defective electrode when, with respect to the first electrode among the at least one electrode, a wavy recess corresponding to a standard shape in which a protruding region (plateau area) that increases to a predetermined level or more from the standard thickness of the first electrode and a recessed region (dip area) that decreases to less than a predetermined level from the standard thickness are continuous, is observed, based on the position of the end of the second electrode among the at least one electrode excluding the first electrode and the position of the wavy recess.

2. The detection device according to claim 1, wherein the reference shape includes at least one of a specified area and a specified depth.

3. The aforementioned processor, The detection device according to claim 1, configured to confirm the recess in a sloped portion formed on at least one electrode, wherein the thickness gradually decreases.

4. The detection device according to claim 3, wherein the inclined portion is formed from cutting or coating in the manufacturing process of at least one electrode.

5. The aforementioned processor, The detection device according to claim 1, configured to confirm the recess at a predetermined range of the upper end of the electrode, oriented toward the other end with respect to the end of the electrode tab formed on at least one electrode.

6. The aforementioned processor, The detection device according to claim 1, configured to obtain a thickness measurement of an electrode assembly in which a positive electrode and a negative electrode having substantially the same size are stacked with a separator membrane in between.

7. The aforementioned processor, The detection device according to claim 1, configured to obtain a thickness measurement of an electrode assembly in which a relatively large negative electrode and a relatively small positive electrode are stacked with a separation membrane in between.

8. The aforementioned processor, When the wavy recess corresponding to the reference shape is confirmed, the distance between the position where the sinking region begins after the protruding region and the end of the positive electrode is confirmed. If the aforementioned distance falls within the specified range, at least one electrode is detected as a normal electrode. The detection device according to claim 7, configured to detect at least one electrode as a faulty electrode when the distance falls outside a specified range.

9. Including additional memory, The aforementioned processor, The reference shape is reset based on the shape of the wavy recess formed in the defective electrode. The detection device according to claim 1, configured to store the reset reference shape in the memory.

10. In the operation method of the detection device, The operation involves obtaining a thickness measurement of at least one electrode, Based on the aforementioned thickness measurement, the operation of confirming the recess formed in the at least one electrode, A method comprising the operation of detecting the first electrode as a defective electrode based on the position of the end of the second electrode, which is one of the at least one electrodes, and the position of the wavy recess, when a wavy recess corresponding to a reference shape in which a protruding region (plateau area) that increases to a predetermined level or more from the reference thickness of the first electrode and a recessed region (dip area) that decreases to a predetermined level from the reference thickness are confirmed with respect to the reference thickness of the first electrode.

11. The method according to claim 10, wherein the reference shape includes at least one of a specified area and a specified depth.

12. The method according to claim 10, further comprising the action of checking the recess in a sloped portion formed on at least one electrode, wherein the thickness gradually decreases.

13. The method according to claim 12, wherein the inclined portion is formed in a cutting step or a coating step among the manufacturing steps of the at least one electrode.

14. The method according to claim 10, further comprising the action of checking the recess at a predetermined range of the upper end of the electrode, oriented toward the other end with respect to the end of the electrode tab formed on at least one electrode.

15. The method according to claim 10, comprising the operation of obtaining a thickness measurement of an electrode assembly in which a positive electrode and a negative electrode having substantially the same size are stacked with a separator membrane in between.

16. The method according to claim 10, comprising the operation of obtaining a thickness measurement of an electrode assembly in which a relatively large negative electrode and a relatively small positive electrode are stacked with a separator membrane in between.

17. When the wavy recess corresponding to the reference shape is confirmed, the distance between the position where the sinking region begins after the protruding region and the end of the positive electrode is confirmed. When the aforementioned distance falls within the specified range, the operation of detecting at least one electrode as a normal electrode is performed. The method according to claim 16, further comprising the operation of detecting at least one electrode as a faulty electrode when the distance falls outside a specified range.

18. The operation of resetting the reference shape based on the shape of the wavy recess formed on the defective electrode, The method according to claim 10, further comprising the operation of saving the reset reference shape.

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