DETECTION DEVICE FOR DETECTING ELECTRODE DEFECTS AND METHOD OF OPERATION THEREOF

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 all contents disclosed in the documents of the Korean patent application are incorporated as part of this specification.

[0002] Various embodiments disclosed herein relate to detection devices and methods of operation for detecting faulty electrodes, and more particularly, to techniques for detecting faulty electrodes that may result in the formation of gaps at the interface with a separation membrane. [Background technology]

[0003] 2. Description of the Related Art Secondary batteries have been increasingly developed and used in recent years due to their advantages of being rechargeable, small in size, and large in capacity.

[0004] Such a secondary battery is manufactured in such a manner that an electrode assembly consisting 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 stacking the cathode and the anode with the separator interposed therebetween, and then applying a predetermined level of heat and pressure. Here, the portions where the electrode and the separator face each other may be housed inside the battery case in a state where they are bonded (e.g., glued) to each other by heat and pressure. Summary of the Invention [Problem to be solved by the invention]

[0005] In general, the bonding state between the electrodes and the separator in the electrode assembly is related to the performance of the secondary battery. For example, if the thickness of the portion where the electrode and the separator face each other (e.g., bonding surface) is uniform, the performance of the secondary battery is guaranteed at a predetermined level. Conversely, if the thickness of at least a portion of the portion where the electrode and the separator face each other is not uniform due to weakening of adhesion or the like, the performance of the secondary battery is not guaranteed at a predetermined level. For example, in the portion of the bonding surface where the thickness is not uniform, the consumption of the electrolyte increases due to high resistance, which may cause swelling of the battery cell and cause lithium precipitation, resulting in a decrease in the performance of the secondary battery.

[0006] At least one of various embodiments of the present invention provides a detection device and an operation method thereof for detecting a faulty electrode that may cause a deterioration in performance of a secondary battery.

[0007] At least one of the various embodiments of the present invention provides a detection apparatus and method of operation for detecting faulty electrodes that may result in the formation of gaps (e.g., spaces) in an electrode assembly based on variations in electrode thickness. [Means for solving the problem]

[0008] 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.

[0009] According to various embodiments, the processor may be configured to identify the wavy depression in a form including a plateau area that increases above a predetermined level from a reference thickness of the at least one electrode and a dip area that decreases below the predetermined level from the reference thickness.

[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 identify the depression in a tapered portion of decreasing thickness formed in the at least one electrode.

[0012] According to various embodiments, the slope may be formed during a cutting or coating step in the manufacturing process of the at least one electrode.

[0013] According to various embodiments, the processor may be configured to identify the depression in a predetermined range of an upper end of an electrode that faces toward the other end relative to an end of an electrode tab formed on the 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 positive and negative electrodes having substantially the same size are stacked with a separator interposed therebetween.

[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 between them.

[0016] According to various embodiments, when a wavy depression corresponding to the reference shape is identified, the processor may be configured to check the distance between the position where a sinking region begins after the protruding region and the end of the positive electrode, and detect the at least one electrode as a normal electrode if the distance is within a specified range, and detect the at least one electrode as a faulty electrode if the distance is outside of 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 a shape of a wavy depression formed in the defective electrode, and to store the reset reference shape in the memory.

[0018] A method of operating a detection device according to various embodiments may include obtaining a thickness measurement value of at least one electrode, checking for a depression formed in the at least one electrode based on the thickness measurement value, and detecting the at least one electrode as a defective electrode if a wavy depression corresponding to a reference shape is confirmed.

[0019] According to various embodiments, the wavy depression may include a shape in which a plateau area that increases above a predetermined level from a reference thickness of the at least one electrode and a dip area that decreases below the 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 method of operation may include identifying the depression in a tapered portion of decreasing thickness formed in the at least one electrode.

[0022] According to various embodiments, the slope may be formed during a cutting or coating step in the manufacturing process of the at least one electrode.

[0023] According to various embodiments, the method may include checking for the depression in a predetermined range of an upper end of an electrode that faces toward the other end based on an end of an electrode tab formed on the at least one electrode.

[0024] According to various embodiments, the method may include 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 interposed therebetween.

[0025] According to various embodiments, the method may include 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 interposed therebetween.

[0026] According to various embodiments, the operating method may include, when a wavy depression corresponding to the reference shape is identified, an operation of identifying a distance between a position where a sinking region begins after the protruding region and an end of the positive electrode, an operation of detecting the at least one electrode as a normal electrode if the distance is within a specified range, and an operation of detecting the at least one electrode as a defective electrode if the distance is outside the specified range.

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

[0028] The detection apparatus and method of operation for detecting electrode defects according to various embodiments disclosed herein enables the manufacture of secondary batteries with guaranteed levels of performance by detecting defective electrodes that may result in the formation of gaps in the electrode assembly based on variations in electrode thickness.

[0029] The advantages obtained from this document are not limited to those mentioned above. [Brief description of the drawings]

[0030] [Figure 1a] 1A-1C are schematic diagrams illustrating secondary batteries according to various embodiments. [Figure 1b] 1A-1C are schematic diagrams illustrating secondary batteries according to various embodiments. [Figure 1c] 1A-1C are schematic diagrams illustrating secondary batteries according to various embodiments. [Diagram 2] 1A-1D illustrate configurations of a detection device for detecting electrode failures according to various embodiments. [Figure 3a] 1A and 1B are diagrams illustrating a defective electrode that causes a gap to be formed in an electrode assembly. [Figure 3b] 1A and 1B are diagrams illustrating a defective electrode that causes a gap to be formed in an electrode assembly. [Figure 4a] 11A to 11C are diagrams for explaining operations for detecting defective electrodes according to various embodiments. [Figure 4b] 11A to 11C are diagrams for explaining operations for detecting defective electrodes according to various embodiments. [Figure 4c] 11A to 11C are diagrams for explaining operations for detecting defective electrodes according to various embodiments. [Figure 4d] 11A to 11C are diagrams for explaining operations for detecting defective electrodes according to various embodiments. [Diagram 5] 11A to 11C are diagrams for explaining other operations for detecting defective electrodes according to various embodiments. [Figure 6a] 1A to 1C are diagrams illustrating the performance of detection devices according to various embodiments. [Figure 6b] 1A to 1C are diagrams illustrating the performance of detection devices according to various embodiments. [Figure 7] 4 is a flowchart illustrating the operation of a detection device according to various embodiments. [Figure 8] 10 is a flowchart illustrating another operation of the detection device according to various embodiments. [Figure 9a] 11A to 11C are diagrams for explaining the operation of setting criteria for determining whether an electrode is good or bad in a detection device according to various embodiments. [Figure 9b] 11A to 11C are diagrams for explaining the operation of setting criteria for determining whether an electrode is good or bad in a detection device according to various embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, some embodiments of the present invention will be described in detail based on the exemplary drawings. When referring to components in each drawing, it should be noted that the same components are referred to by the same reference numerals as much as possible even if they are shown in different drawings. In addition, when describing the embodiments of the present invention, if a detailed description of related known configurations or functions is deemed to hinder understanding of the embodiments of the present invention, the detailed description will be omitted.

[0032] In describing components of the embodiments of the present invention, terms such as 1, 2, A, B, (a), (b) and the like can be used. These terms are merely used to distinguish the components from other components, and do not limit the essence, order, procedure, etc. of the components. In addition, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those having ordinary skill in the art to which the present invention belongs. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with the contextual meaning of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this document.

[0033] Various embodiments and terms used in this document should not be understood as limiting the technical features described in this document to a specific embodiment, but as including various modifications, equivalents, or alternatives of the embodiment. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the item, unless a clearly different meaning is indicated in the relevant context. In this document, each of phrases such as "A or B," "at least one of A and B," "at least one of A or B," "A, B or C," "at least one of A, B and C," "at least one of A, B or C," etc. may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof. Terms such as "first," "second," "first," and "second" may be used simply to distinguish the corresponding component from other corresponding components, and do not limit the corresponding component in other aspects (e.g., importance or procedure). When an element (e.g., a first element) is referred to as being "coupled" or "connected" to another element (e.g., a second element), with or without the terms "functionally" or "communicatively," it means that the element is coupled to the other element directly (e.g., by wire or wirelessly) or through a third element.

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

[0035] 1a to 1c, a secondary battery 100 according to various embodiments may be configured in such a manner that an electrode assembly 120 and an electrolyte are contained in a battery case 110. As shown in FIG.

[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 include a space configured to accommodate at least a portion of the electrode assembly 120, and the second case 114 may include a space configured to accommodate another portion of the electrode assembly 120.

[0037] According to one embodiment, the electrode assembly 120 and the electrolyte may be contained in an internal space formed by combining the first case 112 and the second case 114, and with the electrode assembly 120 and the electrolyte contained therein, the edges of the first case 112 and the edges of the second case 114 may be sealed.

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

[0039] According to one embodiment, each of the electrodes 122, 125 may be formed by applying an active material slurry to a current collector. For example, the slurry may be formed by stirring a granular active material, a supplemental conductor, a binder, a plasticizer, and the like, together with a solvent.

[0040] According to an embodiment, each of the electrodes 122, 125 may have an uncoated portion where no slurry is applied, and such uncoated portion may have an electrode tab 123, 126 attached to the corresponding electrode 122, 125. In addition, one end of the electrode lead 124, 127 may be attached and coupled to each of the electrode tabs 123, 126, and the other end of the electrode lead 124, 127 may be exposed to the outside of the battery case 110 and provided as an electrode terminal to be connected to an external device such as another secondary battery, a load, or a charging device.

[0041] According to various embodiments, each of the electrodes 122, 125 and the separator 121 can be maintained in a bonded (e.g., glued) state by heat and pressure within the electrode assembly 120, and in order to ensure a predetermined level of performance of the secondary battery 100, each of the electrodes 122, 125 and the separator 121 must be bonded to form a bonded surface (e.g., adhesive surface) having a uniform thickness. For example, in a portion where the thickness of the bonded surface is not uniform, the consumption of the electrolyte in the electrode assembly 120 increases, causing swelling of the battery cell, and the performance of the secondary battery 100 may be reduced due to precipitation of lithium.

[0042] In this regard, various embodiments described in detail with reference to the following drawings are capable of detecting at least one of the electrodes 122, 125 that results in a non-uniform thickness bond with the separator 121. Thus, before or after manufacturing the electrode assembly 120, it is possible to detect the electrodes 122, 125 that result in a non-uniform thickness bond with the separator 121, thereby enabling the manufacture of a secondary battery 100 that is guaranteed to have a predetermined level of performance.

[0043] A detection apparatus for detecting defects in the electrodes 122, 125 according to various embodiments is described in detail below with reference to Figures 2-6.

[0044] Fig. 2 is a diagram showing the configuration of a detection device for detecting electrode defects according to various embodiments, Figs. 3a and 3b are diagrams for explaining a defective electrode that causes the formation of a gap in an electrode assembly, Figs. 4a to 4d are diagrams for explaining an operation of detecting a defective electrode according to various embodiments, and Fig. 5 is a diagram for explaining another operation of detecting a defective electrode according to various embodiments.

[0045] 2, the detection device 200 according to various embodiments may be composed of a measurement module 202, a memory 204, an output module 206, and a processor 208. However, this is merely an example, 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 as a configuration of the detection device 200. Also, at least one of the components described above may be integrated with other components.

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

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

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

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

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

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

[0053] For example, the processor 208 may detect at least one electrode 122, 125 that results in a bond with the separator 121 that is not uniform in thickness. As described above, if the thickness of the bonded surface formed by the bond between the at least one electrode 122, 125 and the separator 121 is not uniform, the performance of the secondary battery 100 may be degraded.

[0054] The thickness of the bonding surface may be determined by the shape of at least one of the electrodes 122, 125. For example, referring to Figs. 3a and 3b, when at least one of the electrodes 122, 125 having a region (e.g., a recess) 310 formed therein that is relatively recessed from the surroundings is bonded to the separation membrane 121, a gap (e.g., a space) 320 of a predetermined size is formed in a portion (e.g., a bonding surface) where the at least one of the electrodes 122, 125 and the separation membrane 121 face each other. According to one embodiment, the recess 310 may be a wavy recess including a continuous shape of a region 402 (e.g., a plateau area) where the thickness increases to a predetermined level or more from a reference thickness 401 (e.g., an average thickness) of the surface of the electrodes 122, 125 and a region 404 (e.g., a dip area) where the thickness decreases to less than a predetermined level from the reference thickness 401, as shown in Fig. 4a. The gaps 320 formed by such wavy depressions 310 are areas where at least a portion of the electrodes 122, 125 and at least a portion of the separation membrane 121 are not bonded due to weakened bonding forces (e.g., adhesive forces) around the depressions 310 formed in the electrodes 122, 125, and may result in the creation of a bonding surface with an uneven thickness.

[0055] In this regard, the processor 208 can detect at least one electrode 122, 125 having a morphology in which a dent 310 (e.g., a wavy dent) is formed as a defective electrode that will result in the formation of a gap 320 in the electrode assembly 120 when combined with the separator 120. Thus, it is possible to prevent the electrode assembly 120 having a defective electrode from being manufactured, thereby enabling the manufacture of a secondary battery 100 that is guaranteed to have a predetermined level of performance. The processor 208 according to various related embodiments will be described in detail below.

[0056] According to various embodiments, as part of detecting a faulty electrode, the processor 208 can ascertain a change in thickness of at least one of the electrodes 122, 125. For example, the processor 208 can measure the thickness (e.g., change in thickness) of the 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 or not a recess 310 that is recessed relatively from the surroundings has been formed for at least one of the electrodes 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 or not a wavy recess has been formed, in which a region 402 (e.g., protruding region) where the thickness increases to a predetermined level or more from the reference thickness 401 and a region 404 (e.g., sunken region) where the thickness decreases to less than the predetermined level from the reference thickness 401 are successively formed.

[0058] According to one embodiment, the processor 208 may determine that at least one electrode 122, 125 does not have a dent 310 formed therein if the thickness of that electrode changes in the same direction (or with the same sign).

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

[0060] According to various embodiments, upon identifying a dent 310 formed in at least one electrode 122, 125, the processor 208 may determine whether the identified dent 310 may result in the formation of a gap 320 in the electrode assembly 120 upon coupling of the at least one electrode 122, 125 with the separation membrane 120. For example, the processor 208 may determine that a dent 310 having a specified size and / or a specified depth formed in the at least one electrode 122, 125 may result in the formation of a gap 320.

[0061] According to one embodiment, the processor 208 may determine the depth of the indentation 310 based on a difference 420 between a maximum value 422 corresponding to the maximum thickness of the measurement object (e.g., the maximum thickness of the protruding region) and a minimum value 424 corresponding to the minimum thickness of the measurement object (e.g., the minimum thickness of the sunken region) among the measurements 410 obtained by the measurement module 202, as shown in FIG. 4a. The processor 208 may also determine the size of the indentation 310 based on a continuous range of measurements corresponding to thicknesses below a predetermined level. However, this is merely an example, and various embodiments are not limited thereto. For example, various known techniques may be applied to determine the size and / or depth of the indentation 310 formed in at least one electrode 122, 125.

[0062] The at least one electrode 122, 125 may be defined as a body portion and an upper end portion. The upper end portion may be defined as a region of a predetermined range facing the other end direction based on an end portion of the electrode 122, 125 (e.g., an end portion of the electrode tab 123, 126). The body portion may be defined as the remaining region of the electrode 122, 125 excluding the upper end portion. In general, the recess 310 that causes the formation of the gap 320 in the electrode assembly 120 is relatively more likely to occur in the upper end portion than in the body portion of the electrode 122, 125.

[0063] In this regard, the processor 208 according to various embodiments can limit the determination region for determining whether or not the dent 310 has formed to the upper ends of the electrodes 122, 125.

[0064] According to an embodiment, the electrode assembly 120 may be configured in a form in which the negative electrode 122 and the positive electrode 125 having substantially the same size are stacked with the separator 121 interposed therebetween, as shown in FIG. 4b. In this case, the processor 208 may limit the upper end 430 of a predetermined range (d) facing the other end direction based on the end 431 of the electrode tabs 123 and 126 as the determination region. That is, the processor 208 may omit the operation of determining whether or not the indentation 310 is formed in the main body parts of the electrodes 122 and 125 except for 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 the indentation 310 is formed may be performed only in the main body parts of the electrodes 122 and 125, or may be performed in the upper end parts and the entire main body parts.

[0065] According to another embodiment, the electrode assembly 120 may be configured in a form in which the negative electrode 122 and the positive electrode 125 having different sizes are stacked with a separation film 121 interposed therebetween, as shown in Fig. 4c. In this case, the processor 208 may limit the upper end 440 where the two electrodes 122, 125 do not face each other to the determination region. That is, the processor 208 may determine the presence or absence of the formation of the dent 310 only for the determination region (A+B) including the region A from the end 122-1 of the relatively large first electrode (e.g., the negative electrode 122) to the end 123-1 of the electrode tab 123, and the region B between the end 122-1 of the first electrode and the end 125-1 of the relatively small second electrode 125.

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

[0067] Therefore, the processor 208 can define, based on the inclined portion, a range for obtaining a maximum value corresponding to the maximum thickness of the measurement object and a range for obtaining a minimum value corresponding to the minimum thickness of the measurement object.

[0068] According to one embodiment, the processor 208 may define a boundary 452 of the main body and upper end of the electrodes 122, 125 (e.g., end 125-1 of the second electrode 125 shown in FIG. 4c) as a judgment start point as shown in FIG. 4d, and define a predetermined range from the judgment start point as a maximum value calculation range 454 (e.g., a protruding region detection range). For example, the maximum value calculation range 454 may be in a range of 2 mm to 5 mm from the judgment start point. Preferably, the maximum value calculation range may be within 3 mm from the judgment 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 a minimum value calculation range 458 (e.g., a subsidence area detection range). For example, the minimum value calculation range 458 may be a 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 dents 310 formed in the electrodes 122, 125, as previously described.

[0071] Additionally or alternatively, the processor 208 may further consider the location of the dent 310 in detecting a defective electrode. For example, the closer the dent 310 is to the boundary 452 of the body and upper end of the electrodes 122 and 125 (e.g., the end 125-1 of the second electrode 125 shown in FIG. 4c), the smaller the gap 320 is formed. In relation to this, the processor 208 may determine that an electrode in which a dent 310 that may cause the formation of a gap 320 in the electrode assembly 120 is formed is a normal electrode when a distance 514 between a boundary 510 of the body and upper end of the electrodes 122 and 125 (e.g., the end 125-1 of the second electrode 125 shown in FIG. 4c) and the dent formation location 512 falls within a specified range, as shown in FIG. 5.

[0072] According to one embodiment, the processor 208 can check the end of the protruding region, i.e., the distance 514 between the part 512 where the subsidence region starts and the boundary 510 of the main body and the upper end. For example, the part 512 where the subsidence region starts can be defined as within 5% of the depth of the subsidence region. For example, the distance 514 between the part 512 where the subsidence region starts and the boundary 510 of the main body and the upper end shown in FIG. 5 can also be defined as the width of the protruding region. In other words, an electrode in which a subsidence region is formed continuously with a protruding region having a width within a specified range can be determined to be a normal electrode. On the other hand, an electrode in which a subsidence region is formed continuously with a protruding region having a width exceeding the specified range can be determined to be a defective electrode.

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

[0074] 6a and 6b, it can be seen that a gap 320 can be formed in the electrode assembly 120 by at least one of the electrodes 122, 125.

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

[0076] For example, the third target electrode (case 3) 605 is a reference electrode that is a standard for determining whether the electrode is good or bad. It can be seen that the shape of the first target electrode (case 1) 601 is a shape in which the thickness gradually decreases with a similar decrease width as 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 the formation of a gap.

[0077] On the other hand, it can be seen that the shape of the second target electrode (case 2) 603 is a shape in which the thickness is reduced at a different rate from that of the third target electrode 605. This means that the thickness 613 of the second target electrode 603, which has an inflection point where the direction of the thickness change changes, unlike the thickness change 615 of the third target electrode 605, can be detected as the thickness of a defective electrode that causes the formation of a gap.

[0078] FIG. 6b shows an electrode assembly 120 fabricated with a target electrode, and shows that the detection result of FIG. 6a is highly accurate.

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

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

[0081] As previously described, the detection apparatus 200 according to various embodiments can accurately detect faulty electrodes that may result in the formation of gaps in the electrode assembly 120 based on variations in the thickness of the electrodes 122,125.

[0082] Hereinafter, with reference to Figs. 7 to 9b, the operation methods of the detection devices according to various embodiments will be described in detail.

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

[0084] 7, in operation 710, the detection device 200 (e.g., the processor 208) can measure the thickness of the negative electrode 122 coupled to the positive electrode 125. According to one embodiment, the detection device 200 can measure the thickness of the negative electrode 122 in a state in which the relatively large negative electrode 122 and the relatively small positive electrode 125 are stacked with a separator 121 interposed between them, as shown in FIG.

[0085] According to various embodiments, the detection device 200 (e.g., the processor 208) can determine whether or not a gap 320 has formed in the bonded region based on the measured thickness in operation 720. 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 the gap 320. For example, the detection device 200 can determine whether or not a dent 310 having a specified depth and / or size has been 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 dent has been formed, in which a region 402 (e.g., a protruding region) that increases above a predetermined level from the reference thickness 401 (e.g., an average thickness) on the surface of the electrodes 122, 125 is continuous with a region 404 (e.g., a sunken region) that decreases below a predetermined level from the reference thickness 401.

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

[0087] 8 is a flow chart illustrating another operation of the detection apparatus according to various embodiments. The operations of FIG. 8 described below may illustrate various embodiments of operation 730 of FIG.

[0088] Referring to FIG. 8, a detection apparatus 200 (eg, processor 208 ) according to various embodiments can determine the location of a dent 310 formed in the negative electrode 122 in operation 810 .

[0089] According to various embodiments, the detection device 200 (eg, the processor 208 ) can determine whether the location of the dent 310 falls within a predetermined distance relative to an edge of the positive electrode 125 in operation 820 .

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

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

[0092] 9a and 9b are diagrams for explaining the operation of setting a quality judgment criterion for electrodes in detection devices according to various embodiments.

[0093] 9a and 9b, the detection device 200 according to various embodiments can set a standard for determining pass / fail based on the result (or analysis result) of the pass / fail determination for the electrodes 122, 125.

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

[0095] According to various embodiments, the detection device 200 may set the stored approximation value (910) of the shape of the dent as a criterion for determining whether the electrode is normal. For example, as shown in FIG. 9b, a range of the dent 310 to be determined as normal may be specified (920) based on the shape of the dent 310 confirmed in the normal electrode. Such a criterion may be updated every time a pass / fail determination operation is performed. Thus, the detection device 200 may determine an electrode in which the dent 310 included in the specified range is formed as a normal electrode, and determine an electrode in which the dent 310 not included in the specified range is formed as a defective electrode.

[0096] As described above, the detection device 200 according to various embodiments may set a criterion for determining whether the electrodes 122, 125 are normal based on the result of the determination of whether the electrodes 122, 125 are normal. However, this is merely an example, and the various embodiments are not limited thereto. For example, the detection device 200 according to various embodiments may store the shape of the dent 310 formed on the electrodes 122, 125 determined to be defective, and set an approximation of the shape of the stored dent 310 as a criterion for determining whether the electrodes 122, 125 are defective.

[0097] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0098] Therefore, the embodiments disclosed in the present invention are for illustration purposes only and are not intended to limit the technical idea of ​​the present invention, and such embodiments do not limit the scope of the technical idea of ​​the present invention. The scope of protection of the present invention should be interpreted according to the appended claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in 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 tab 123-1 End 124, 127 Electrode lead 125-1 End 200 Detection Device 202 Measurement Module 204 Memory 206 Output Module 208 processors 310 Dent 320 Gap

Claims

1. 1. A detection device for detecting a defective electrode, comprising: a measurement module configured to obtain a thickness measurement of the at least one electrode; a processor electrically connected to the measurement module; The processor, determining a depression formed in the at least one electrode based on the thickness measurements; A detection device configured to detect the at least one electrode as a defective electrode when a wavy depression corresponding to a reference shape is identified.

2. The processor, 2. The detection device of claim 1, wherein the detection device is configured to check the wavy depression in a form in which a plateau area that increases to a predetermined level or more from a reference thickness of the at least one electrode and a dip area that decreases to a predetermined level or less from the reference thickness are continuous.

3. The detection apparatus of claim 1 , wherein the reference shape includes at least one of a specified area and a specified depth.

4. The processor, The detection device of claim 1 , configured to identify the depression in a tapered portion of decreasing thickness formed in the at least one electrode.

5. The detection device according to claim 4 , wherein the inclined portion is formed by cutting or coating during a manufacturing process of the at least one electrode.

6. The processor, The detection device according to claim 1 , configured to check the depression in a predetermined range of an upper end portion of the electrode that faces toward the other end with respect to an end portion of an electrode tab formed on the at least one electrode as a reference.

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

8. The processor, 3. The detection device according to claim 2, 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 interposed therebetween.

9. The processor, When a wavy depression corresponding to the reference shape is confirmed, a distance between a position where a sinking region starts after the protruding region and an end of the positive electrode is confirmed; If the distance is within a specified range, the at least one electrode is detected as a normal electrode; The detection apparatus of claim 8 , configured to detect the at least one electrode as a faulty electrode if the distance falls outside a specified range.

10. Further comprising a memory; The processor, resetting the reference shape based on the shape of the wavy recess formed in the defective electrode; The detection apparatus of claim 1 , configured to store the reset reference shape in the memory.

11. 1. A method of operating a detection device, comprising: obtaining a thickness measurement of at least one electrode; determining a depression formed in the at least one electrode based on the thickness measurements; and and detecting the at least one electrode as a defective electrode if a wavy depression corresponding to a reference shape is identified.

12. The wavy depressions are The method of claim 11, wherein the at least one electrode has a plateau area that increases to a predetermined level or more from the reference thickness and a dip area that decreases to a predetermined level or less from the reference thickness.

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

14. The method of claim 11 , comprising the act of identifying the recess in a tapered portion of decreasing thickness formed in the at least one electrode.

15. The method according to claim 14 , wherein the inclined portion is formed during a cutting or coating step in a manufacturing process of the at least one electrode.

16. The method according to claim 11 , further comprising the step of: checking for the depression in a predetermined range of upper ends of the electrodes facing in a direction toward the other end with respect to an end of an electrode tab formed on the at least one electrode.

17. The method according to claim 11 , comprising 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 with a separator interposed therebetween.

18. The method of claim 12 , comprising 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 interposed between them.

19. When a wavy depression corresponding to the reference shape is confirmed, a step of confirming a distance between a position where a sinking region starts after the protruding region and an end of the positive electrode; detecting the at least one electrode as a normal electrode when the distance is within a specified range; and detecting the at least one electrode as a faulty electrode if the distance falls outside a specified range.

20. an operation of resetting the reference shape based on a shape of a wavy recess formed in the defective electrode; and saving the reset reference shape.

Images