Inspection apparatus and method for detecting defects in electrode tabs of electrode assemblies

Abstract

An inspection apparatus for detecting defects in electrode tabs of an electrode assembly, wherein the electrode tabs are disposed at longitudinal ends of the electrode assembly. The inspection apparatus includes a radiation emitting device and a radiation measuring device. The radiation emitting device is configured to emit X-rays or beta rays toward the electrode tabs, and the radiation measuring device is arranged opposite the radiation emitting device to position the electrode tabs between them. The radiation measuring device is configured to measure the amount of X-rays or beta rays transmitted through the electrode tabs. The inspection apparatus also includes a processor configured to process a signal corresponding to the measured amount of X-rays or beta rays, and to determine a defect if the amount of X-rays or beta rays measured at a portion within the electrode tabs shows a decrease of a predetermined threshold or more compared to a reference value.

Description

Technical Field

[0001] The present invention relates to an inspection apparatus for detecting defects in electrode terminals of an electrode assembly and a method for detecting defects in electrode terminals of an electrode assembly.

[0002] More specifically, the present invention relates to an inspection apparatus for detecting defects in the electrode tabs of an electrode assembly, capable of effectively identifying defective electrode tabs and preventing electrode assemblies with defective electrode tabs from being conveyed downstream of the electrode assembly manufacturing process, and a method for detecting defects in the electrode tabs of an electrode assembly. Background Technology

[0003] Secondary batteries, or rechargeable batteries, can be discharged through use and then restored to their original state through charging. They have recently been widely used as a power source for wireless devices such as personal digital devices, mobile phones, and laptops. Furthermore, secondary batteries are gaining attention as a power source for electric vehicles, hybrid vehicles, and other vehicles considered a solution to the air pollution problems caused by the use of fossil fuels in conventional gasoline or diesel vehicles. Due to their significant advantages over other conventional energy sources, the applications of secondary batteries are becoming increasingly widespread, and consumer demand for them is also increasing.

[0004] Among various rechargeable batteries, lithium batteries are particularly widely used as a power source for various electronic products because they exhibit high energy density, high operating voltage, and excellent storage and lifespan characteristics.

[0005] Meanwhile, secondary batteries can also be classified according to the shape of their casing. For example, they can be classified as cylindrical or prismatic batteries, in which case the electrode assembly is embedded in a cylindrical or prismatic metal can. Furthermore, in the case of pouch batteries, the electrode assembly is embedded in a pouch-shaped casing made of aluminum laminates.

[0006] The electrode assembly embedded in the battery casing serves as a power generation element capable of charging and discharging. The electrode assembly includes a positive electrode, a negative electrode, and a separator inserted between the positive and negative electrodes.

[0007] Electrode assemblies can generally be classified into rolled-core type and stacked type. In the case of rolled-core type electrode assemblies, long sheet-shaped positive and negative electrodes coated with active material are wound along their longitudinal direction, with spacers inserted between them. On the other hand, in the case of stacked type electrode assemblies, multiple positive and negative electrodes of predetermined size are sequentially stacked on top of each other, with spacers inserted between them.

[0008] The uncoated portions of the stacked electrodes form the electrode terminals of the electrode assembly. However, defects may occur in the electrode terminals during the formation of the electrode assembly.

[0009] Therefore, it would be beneficial to develop technologies that can solve the aforementioned technical problems. Summary of the Invention

[0010] Technical issues

[0011] The object of this invention is to provide an inspection apparatus / method for detecting defects in electrode assemblies. This problem is solved or alleviated at least in part by the subject matter of the independent claims, wherein further examples are incorporated in the dependent claims.

[0012] Technical solution

[0013] One aspect of the invention relates to an inspection apparatus for detecting defects in electrode tabs of an electrode assembly. The electrode tabs may be disposed at a longitudinal end of the electrode assembly. The inspection apparatus includes a radiation emitting device and a radiation measuring device, the radiation emitting device being configured to emit X-rays or beta rays toward the electrode tabs, and the radiation measuring device being arranged opposite the radiation emitting device such that the electrode tabs are positioned between them. The radiation measuring device may be configured to measure the amount of X-rays or beta rays transmitted through the electrode tabs. The inspection apparatus may further include a processor configured to process a signal corresponding to the measured amount of X-rays or beta rays, and to determine a defect if the amount of X-rays or beta rays measured at a portion within the electrode tabs shows a decrease of a predetermined threshold or more compared to a reference value.

[0014] This invention enables the effective identification of defects in the electrode tabs of an electrode assembly at an early stage—particularly as early as when the electrode tabs are formed through the tab welding process. Furthermore, it allows the process to be performed in a non-destructive manner.

[0015] According to an embodiment of the present invention, the reference value may be the average amount of X-rays or β-rays measured at adjacent portions within the electrode terminals.

[0016] This enables the inspection apparatus of the present invention to achieve accurate defect identification. For example, the electrode tabs of an electrode assembly may have uneven thickness within their surface, depending on location. This may be caused by multiple unit electrode tabs forming the electrode tabs, with corresponding unit electrode tabs among the multiple unit electrode tabs possibly having uneven thickness at different locations within their surfaces. The aforementioned predetermined threshold needs to be set large enough that such uneven thickness of the electrode tabs is not identified as a defect. For example, the predetermined threshold can be set to approximately within the thickness range of one or two unit electrode tabs. By using a set of reference values ​​set based on average measurements at adjacent portions and the predetermined threshold set as described above, the inspection apparatus of the present invention can accurately identify defects in the electrode tabs, thereby avoiding fault detection, for example, due to variations in the thickness of the electrode tabs.

[0017] According to an embodiment of the present invention, the reference value may be a user-preset expected amount of X-rays or beta rays.

[0018] In other words, it allows users to determine reference values ​​based on previously recorded data or product specifications. Therefore, this invention enables users to control the process of identifying defects in electrode assemblies in a simple way, such as in terms of accuracy or speed.

[0019] According to an embodiment of the invention, the inspection apparatus may also have a controller configured to repeatedly perform inspections at multiple locations within the electrode terminals by moving the radiation emitting device / radiation measuring device relative to the electrode terminals.

[0020] Therefore, the present invention can improve the accuracy of inspection by identifying defects even in small corner areas of the electrode contacts. Furthermore, this allows the inspection device according to the invention to be configured in a small and compact manner.

[0021] According to an embodiment of the present invention, the radiation emitting device / radiation measuring device can be moved relative to the electrode terminals at least in the longitudinal direction of the electrode assembly.

[0022] Therefore, the inspection device according to the invention can have improved accuracy and, if desired, can even be configured to be small and compact.

[0023] Another aspect of the invention relates to an inspection method for detecting defects in electrode tabs of an electrode assembly. The electrode tabs may be disposed at a longitudinal end of the electrode assembly. The inspection method may include: 1) emitting x-rays or beta rays toward the electrode tabs by a radiation emitting device; 2) measuring the amount of x-rays or beta rays transmitted through the electrode tabs by a radiation measuring device; and 3) identifying a defect if the amount of x-rays or beta rays measured at a portion within the electrode tabs shows a decrease of a predetermined threshold or more compared to a reference value.

[0024] Therefore, the method according to the invention enables the effective identification of defects in the electrode tabs of the electrode assembly at an early stage—particularly as early as when the electrode tabs are formed through the tab welding process. Furthermore, this allows the process to be performed in a non-destructive manner.

[0025] According to an embodiment of the present invention, the reference value may be the average amount of X-rays or β-rays measured at adjacent portions within the electrode terminals.

[0026] This enables the inspection method of the present invention to achieve accurate defect identification. For example, the electrode tabs of an electrode assembly may have uneven thickness within their surface, depending on location. This may be caused by multiple unit electrode tabs forming the electrode tabs, with corresponding unit electrode tabs among the multiple unit electrode tabs possibly having uneven thickness at different locations within their surfaces. The aforementioned predetermined threshold needs to be set large enough that such uneven thickness of the electrode tabs is not identified as a defect. For example, the predetermined threshold can be set to approximately within the thickness range of one or two unit electrode tabs. By using a set of reference values ​​set based on average measurements at adjacent portions and the predetermined threshold set as described above, the inspection method of the present invention can accurately identify defects in the electrode tabs, thereby avoiding fault detection, for example, due to varying thickness of the electrode tabs.

[0027] According to an embodiment of the present invention, the reference value may be a user-preset expected amount of X-rays or beta rays.

[0028] In other words, it allows users to determine reference values ​​based on previously recorded data or product specifications. Therefore, this invention enables users to control the process of identifying defects in electrode assemblies in a simple way, such as in terms of accuracy or speed.

[0029] According to an embodiment of the invention, steps 1) and 2) can be repeatedly performed at multiple locations within the electrode terminals by moving the radiation emitting device / radiation measuring device relative to the electrode terminals.

[0030] Therefore, the present invention can improve the accuracy of inspection by identifying defects even in small corner areas of the electrode contacts. Furthermore, this allows the inspection device according to the invention to be configured in a small and compact manner.

[0031] According to an embodiment of the present invention, the radiation emitting device / radiation measuring device can be moved relative to the electrode terminals at least in the longitudinal direction of the electrode assembly.

[0032] Therefore, the inspection method according to the invention can have improved accuracy and, if desired, can even be configured to be small and compact.

[0033] According to embodiments of the present invention, the inspection can be performed after the electrode terminals are formed by welding multiple single-layer electrode terminals of the corresponding electrode sheet of the electrode assembly—or preferably immediately after the electrode terminals are formed by welding multiple single-layer electrode terminals of the corresponding electrode sheet of the electrode assembly.

[0034] By doing so, the present invention enables the identification of defects immediately after the formation of the electrode tabs and before the electrode assembly moves further to the next process. In this case, the frequency with which defects in the electrode tabs are identified can indicate the status of the welding process. With a high defect identification frequency, the user can perform inspections and maintenance on the welding process.

[0035] According to an embodiment of the invention, an inspection can be performed after the leads are soldered onto the electrode terminals.

[0036] Therefore, the present invention enables the identification of defects that occur during the process of soldering electrode terminals or soldering leads to electrode terminals.

[0037] Beneficial effects

[0038] The inspection apparatus and method for detecting defects in electrode terminals of an electrode assembly according to the present invention enable the effective identification of defective electrode terminals as early as during the electrode manufacturing process when the electrode terminals are formed. Therefore, the accuracy of detecting defective electrode terminals can be improved. Furthermore, electrode assemblies with defective electrode terminals can be removed from the production line at the earliest possible time, without being conveyed downstream of the electrode assembly manufacturing process. Therefore, the overall throughput of the electrode assembly manufacturing process can be increased. Attached Figure Description

[0039] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings. The invention is explained in more detail below using exemplary embodiments specified in the schematic diagrams of the drawings, in which: Figure 1 and Figure 2The diagram schematically illustrates the welding process of a bundle of unit electrode terminals for forming an electrode assembly, according to related technologies. Figure 3 This is a schematic diagram of an inspection apparatus for detecting defects in electrode terminals of an electrode assembly according to an embodiment of the present invention. Figure 4 The diagram schematically illustrates a side-view cross-sectional view of an inspection apparatus for detecting defects in electrode terminals of an electrode assembly according to an embodiment of the present invention, the apparatus inspecting electrode terminals of a moving electrode assembly on a conveyor. Figure 5 The diagram schematically illustrates an inspection apparatus for detecting defects in electrode terminals of an electrode assembly according to an embodiment of the present invention, and shows the processing of signals obtained by the apparatus. Figure 6 (a) to Figure 6 (c) is a schematic diagram of three variations of the radiation measuring device according to an embodiment of the present invention. Figure 7 This is a schematic diagram of an inspection apparatus for detecting defects in electrode terminals of an electrode assembly according to an embodiment of the present invention. Detailed Implementation

[0040] The terms or words used in this specification and claims should not be construed as having a general meaning or dictionary-based meaning, but should be interpreted as having the meaning and concept consistent with the technical spirit of the invention in the broadest possible way.

[0041] In this disclosure, it should be understood that the terms “comprising,” “including,” “having,” etc., specify the presence of the stated features, quantities, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, or combinations thereof.

[0042] Furthermore, when a portion such as a layer, membrane, region, or plate is referred to as being "on" another portion, this includes not only the case where the portion is "directly on" the other portion, but also the case where another portion is inserted between them. Conversely, when a portion such as a layer, membrane, region, or plate is referred to as being "below" another portion, this includes not only the case where the portion is "directly below" the other portion, but also the case where another portion is inserted between them. Additionally, the arrangement "on" in this disclosure can include both lower and upper arrangements.

[0043] Various components may be described using terms such as "first" and "second," but components should not be limited by these terms. Terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component without departing from the scope of the invention, and similarly, a second component may be referred to as a first component. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0044] Furthermore, the same reference numerals will be used throughout the accompanying drawings to refer to components that perform similar functions or operations. In this disclosure, when a component is referred to as being connected to another component, this means not only that the one component can be directly connected to the other component, but also that the one component can be indirectly connected to the other component via the other component. Moreover, unless otherwise stated, including a particular element does not mean excluding other elements, but rather means that such elements may be further included.

[0045] In the following, with reference to the accompanying drawings, an inspection apparatus and method according to the present invention for detecting defects in electrode terminals of an electrode assembly will be described in detail.

[0046] The electrode sheet may have a structure in which an electrode mixture layer is coated on one or both sides of the current collector layer.

[0047] The electrode mixture layer can be a slurry containing active materials, a binder, and a solvent, where the binder helps to hold the active material particles together and adhere them to the current collector layer. Active materials are components that undergo electrochemical reactions during charge and discharge cycles in a secondary battery to store and release energy. For example, one or more of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, nickel manganese, and nickel cobalt aluminum oxide can be used as cathode active materials. For example, one or more of graphite, lithium titanate, and silicon-based materials can be used as anode active materials.

[0048] The current collector layer can be a thin metal foil designed to conduct current between the electrochemical active material and the external circuitry of the battery. For example, an aluminum layer can be used for the cathode current collector, while a copper layer can be used for the anode current collector. Additional coatings can be applied to the current collector layer to improve adhesion to the active material, enhance corrosion resistance, or reduce resistance.

[0049] An electrode mixture layer can be coated onto a current collector layer to a desired thickness in a desired region. The coated portion can be positioned along its width in the middle of the electrode sheet, and uncoated portions can be positioned, for example, on either side of the coated portion. Various methods can be used in the coating process. For example, the slurry can be uniformly distributed across the surface of the current collector layer using blades. The slurry can be extruded onto a moving current collector layer using a narrow-groove die. The current collector can be immersed in the slurry and then removed at a controlled speed. Alternatively, the slurry can be atomized and sprayed onto the current collector.

[0050] After coating the electrode mixture layer onto the current collector layer, a process is performed to increase the density of the coated electrode mixture layer, commonly referred to as a drying and pressing process. This process reduces the thickness of the electrode sheet to achieve the desired density, which enhances both the energy density and mechanical integrity of the electrode sheet. For example, a heavy roller with a heater can be used to press the electrode sheet. During this process, pressure is applied to the electrode sheet through the heavy roller.

[0051] A process called grooving can be performed on the uncoated portion of the electrode sheet used to form the electrode tab. During the grooving process, portions of the electrode sheet are selectively removed or cut to create an electrode tab in which the coated electrode mixture is absent. This process can be accomplished using precision tools such as lasers or mechanical molds. The electrode tab is designed to leave specific areas of the current collector layer for attaching electrode leads. The electrode leads can be metal strips used to connect the electrode tab to external battery terminals. The electrode tab can be executed with specific patterns, such as rectangular, U-shaped, or V-shaped cuts, to optimize the attachment of the electrode leads and ensure a good electrical connection.

[0052] Figure 1 and Figure 2 An exemplary apparatus for manufacturing electrode assemblies, and in particular for forming electrode terminals of electrode assemblies, is schematically shown according to the related art.

[0053] refer to Figure 1 The electrode assembly 10 includes a plurality of unit electrode cells, each of which has its own electrode terminal piece (hereinafter referred to as "unit electrode terminal piece") disposed at one end. The corresponding unit electrode terminals of the plurality of unit electrode cells are stacked on top of each other and connected via... Figure 1 The processes shown are welded together to form the electrode tabs 20 of the electrode assembly 10. If necessary, the resulting welded electrode tabs 20 are electrically connected to electrode leads in a subsequent manufacturing process. When the electrode assembly 10 thus manufactured is housed in a sealed state within a battery casing, the electrode assembly 10 can be electrically connected to the outside directly via the electrode tabs 20, or, depending on the circumstances, further electrically connected to the outside via electrode leads.

[0054] To form electrode terminals 20 by welding unit electrode terminals, a terminal welding apparatus 300 can be used, which performs ultrasonic welding on a bundle of layered unit electrode terminals. The welding apparatus 300 applies high-frequency (e.g., about 20 kHz) vibrations generated by ultrasonic waves, while the unit electrode terminals 20 are fixedly positioned between a horn 310 and an anvil 320. In this document, ultrasonic waves can be generated by rapid relative movement between the horn 310 and the anvil 320. During this process, vibrational energy is converted into heat energy through frictional movement between the layers of unit electrode terminals; and this heat energy enables the unit electrode terminals to be welded to each other, thereby forming the electrode terminals 20 of the electrode assembly 10.

[0055] However, during the welding process, defects 30 may occur within the electrode terminals 20 of the electrode assembly 10 for various reasons, such as... Figure 2 As shown in the diagram. One exemplary cause of the defect 30 within the electrode tab 20 is the relative movement between the horn 310 and the anvil 320, which enables welding. When the vibratory force transmitted from the horn 310 and the anvil 320 is applied horizontally to the bundle of unit electrode tabs, frictional movement occurs between the layers of the unit electrode tabs. On the one hand, this frictional movement facilitates the desired welding of the unit electrode tabs. However, on the other hand, the unit electrode tabs—particularly the inner layers—may deform and be damaged, for example, due to the interaction of frictional forces applied between the different layers of the unit electrode tabs.

[0056] The problem is that defects are difficult to identify. In particular, when defects are located inside the electrode contacts, they cannot be easily detected from the outside without damaging the welded electrode contacts.

[0057] To screen out such defective electrode assemblies, the electrical characteristics of the manufactured electrode assemblies are measured once the electrode leads are connected to the electrode terminals. However, measuring electrical characteristics cannot guarantee the effective screening of all possible defects present in the electrode terminals of the electrode assembly. This is because, despite the presence of such defects in the electrode terminals, the electrical characteristics of the defective electrode assembly may still meet product specifications in the initial stage. However, as the electrode assembly is used, the defects in the electrode terminals will grow over time, potentially shortening the lifespan of the electrode assembly and leading to a decrease in the performance of the secondary battery.

[0058] Figure 3 An inspection apparatus for manufacturing electrode assemblies according to an embodiment of the present invention is shown.

[0059] The inspection device can effectively identify defects in the electrode terminals of the electrode assembly at an early stage—especially as early as when the electrode terminals are formed through the terminal welding process.

[0060] X-rays or beta rays can be used to detect defects in the electrode tabs of an electrode assembly because they are a non-contact and non-destructive method that preserves the integrity of the target material. Therefore, this method can be used to detect defects in the electrode tabs of an electrode assembly. The metrology device can have a source section for emitting rays and a detection section for measuring the intensity of radiation that has passed through the target material. An X-ray tube or X-ray generator can be used as the source for emitting X-rays, and strontium-90 (Sr-90) or krypton-85 (Kr-85) can be used as the source material for beta rays. Regarding the detection section, a scintillation detector or semiconductor detector can be used as an exemplary X-ray detector, and on the other hand, a Geiger-Müller tube or scintillation detector can be an example of a beta ray detector.

[0061] Figure 3 The electrode assembly 10 shown is inspected after a tab welding process. The electrode assembly 10 has a structure in which a positive electrode, a separator, and a negative electrode are sequentially stacked on top of each other. The separator is positioned between the positive and negative electrodes to electrically isolate the two electrodes with different polarities from each other. Each unit electrode, forming a single layer within the electrode assembly 10, has its own (unit) electrode tab at one terminal end of its body—typically at the longitudinal end. After the tab welding process, the stacked unit electrode tabs are welded together to form the electrode tabs 20 of the electrode assembly 10.

[0062] The inspection apparatus 100 of this embodiment is specifically configured to detect defects 30 in the electrode terminals 20 of the electrode assembly 10. The inspection apparatus 100 includes, for example, a radiation emitting device 110 configured to emit X-rays or beta rays toward the electrode terminals 20. Additionally, the inspection apparatus 100 includes a radiation measuring device 120 configured to receive X-rays or beta rays from the outside and measure their quantity. The radiation emitting device 110 and the radiation measuring device 120 are arranged on opposite sides facing each other. A space is provided between the radiation emitting device 110 and the radiation measuring device 120, in which the object of inspection—the electrode terminals 20 of the electrode assembly 10—can be positioned.

[0063] The radiation measuring device 120 can be configured to receive and measure the amount of x-rays or beta rays transmitted through the electrode tab 20. The inspection device 100 may also include a processor 130 configured to process the signal corresponding to the measured amount of x-rays or beta rays and to determine whether a defect 30 exists in the electrode tab 20 based on the amount of radiation detected at a specific location within the electrode tab 20.

[0064] The radiation used by the inspection device 100 of the present invention may include, but is not limited to, beta rays and X-rays. High-energy X-ray radiation is required to detect defects within the electrode assembly 20, which is formed by multiple stacked unit electrode tabs. Since high X-ray energy can be harmful to humans, it is subject to stringent safety requirements. Therefore, devices employing high X-ray energy typically need to be constructed as enclosed X-ray systems. On the other hand, devices employing beta rays are not subject to such stringent safety requirements and therefore do not require enclosed systems. Therefore, between the two types of radiation, beta rays have an advantage over X-rays because they are more suitable for inspecting electrode assemblies 10, for example, in… Figure 4 The real-time check is performed while the conveyor 300 is moving as shown.

[0065] For example, the presence of a defect 30 in the electrode terminal 20 can be identified by measuring the absorptivity of radiation at a corresponding location on the electrode terminal 20. Suppose a defect 30 exists at a specific location on one of the unit electrode terminals, such as... Figure 3 As shown, more β particles can pass through the electrode patch 20 at the location corresponding to the defect 30 compared to other adjacent locations on the electrode patch 20. Therefore, ultimately more β particles will reach the radiation measuring device 120 at the location corresponding to the defect 30.

[0066] The radiation measuring device 120 may be an ionization chamber filled with an inert gas and connected to a high voltage. Electrodes in this chamber are connected to a sensitive amplifier and attract beta particles entering the radiation measuring device 120 after passing through electrode tabs 20. Through this reaction, the current is amplified and converted into a voltage proportional to the number of beta particles entering the radiation measuring device 120.

[0067] Figure 5 The diagram schematically illustrates how processor 130 processes signals corresponding to the amount of β particles detected at multiple locations on electrode patch 20 along the Y-axis (i.e., along the longitudinal direction of electrode patch 20). The amount of β particles measured at the respective locations is converted into voltage signal values ​​and preferably recorded in memory along with data identifying the corresponding measurement locations on electrode patch 20.

[0068] The size of each measurement location and / or the distance between two adjacent measurement locations can be determined differently depending on various factors—including, for example, the specifications of the electrode assembly 10. For example, if it is desired not only to know the presence of a defect, but also to know the precise location of the defect, it is necessary to increase the number of measurement locations and / or decrease the distance between adjacent measurement locations.

[0069] When a detailed image of the electrode tab, including the precise location of defects, is desired, X-rays can be used as radiation. On the other hand, for real-time inspection of moving electrode tabs, beta rays are preferred as radiation because the inspection apparatus 100 can have a simpler configuration, for example, employing a moving conveyor 300. As an example, when using beta rays, the distance between measurement positions on the electrode tab 20 can be approximately 1 mm, while when using X-rays, this distance can preferably be set in the range of 100 μm to 200 μm, or, depending on the situation, less than 100 μm. Meanwhile, the resolution of beta rays can be, but is not limited to, 1 mm x 1 mm.

[0070] To improve accuracy, the check can be performed more than twice at each corresponding measurement location on the electrode terminal 20. In this case, multiple measurement values ​​M1, M2, and M3 can be obtained from a single measurement location, such as... Figure 5 As shown in the diagram. The processor 130 can then derive a representative single value from those multiple measurements M1, M2, and M3. For example, the processor 130 can calculate the average of the measurements M1, M2, and M3 to subsequently determine whether a defect exists at the corresponding measurement location.

[0071] According to another embodiment of the invention, radiation measurements can be performed not only at multiple locations of the electrode terminals 20 arranged along the Y-axis, but also at multiple locations along its perpendicular direction (i.e., along the X-axis). That is, radiation measurements can be performed at several different locations on the electrode terminals 20 arranged along the width of the electrode terminals 20. For this purpose, as... Figure 6 As shown in (a), the radiation measuring device 120a includes a plurality of sensors 160 arranged not only along the Y-axis but also along the X-axis. In this case, M1, M2, and M3 may correspond to values ​​obtained from different measuring portions arranged along the X-axis. For example, M1 corresponds to the values ​​obtained from different measuring portions arranged along the X-axis. Figure 6 (a) The value measured by sensor 160-1 in the lowest row of the radiation measuring device 120a. M2 can correspond to the value measured by sensor 160-2 in the middle row. M3 can correspond to the value measured by sensor 160-2 in the middle row. Figure 6 (a) The value measured by sensor 160-3 located in the top row. If defect 30 is located not only in the middle of electrode terminal 20 along its width (X-axis) but also on its side, then multi-row sensors 160-1, 160-2, 160-3 enable inspection device 100 to detect defect 30 more accurately.

[0072] To determine whether a measured voltage value falls within the defect range, the processor 130 can compare the voltage value with a reference value or a predetermined threshold. The reference value could be, for example, the average of measurements obtained from several adjacent measurement locations within the electrode tab. Alternatively, the reference value could be an absolute value preset by the user taking into account various factors such as the type of radiation, electrode specifications, etc.

[0073] According to another embodiment of the invention, the radiation measuring device 120b may have a single row of multiple sensors 160 for measuring radiation quantities; see also Figure 6 (b). The radiation measuring device 120b according to this embodiment can be along the width direction of the electrode terminal block 20, that is, along... Figure 6 The X-axis in (b) is moved relative to the electrode assembly. Inspections using the apparatus of this embodiment can be performed while the electrode assembly 10 is stationary at the inspection position. By moving the radiation measuring device 120b along the width direction of the electrode assembly, multiple measurement values ​​M1, M2, and M3 along the width direction of the electrode tabs can be obtained.

[0074] Meanwhile, even as the electrode assembly 10 moves on the conveyor 300, multiple measurement values ​​M1, M2, and M3 can still be obtained along the width direction of the electrode tabs by appropriately setting the moving speed of the radiation measuring device 120b relative to the moving speed of the electrode assembly 20 on the conveyor 300. For example, the moving speed of the radiation measuring device 120b can be set to be significantly higher than the moving speed of the electrode assembly 20 on the conveyor 300.

[0075] According to another embodiment of the present invention, such as Figure 6 As shown in (c), the radiation measuring device 120c may have a sensor 160. The radiation measuring device 120c and the radiation emitting device 110 may be connected to the mobile systems 150-1 and 150-2, respectively, for example, as shown in [example image]. Figure 7 The track shown. Furthermore, the device may include a controller 140 configured to repeatedly perform checks on the electrode tabs 20 at multiple locations by moving the radiation emitting device 110 and the radiation measuring device 120c together relative to the electrode tabs 20. Reference Figure 7 The radiation emitting device 110 and the radiation measuring device 120c can be moved relative to the electrode terminals 20, at least in the longitudinal direction of the electrode assembly 10 and preferably also in the width direction of the electrode assembly 10. The controller 140 and the processor 130 can be configured as two separate units, or they can be integrated into a single unit.

[0076] According to another aspect of the invention, an inspection method for detecting defects in an electrode assembly, specifically an electrode tab 20, is provided. According to this inspection method, X-rays or beta rays are emitted toward the electrode tab 20 by a radiation emitting device 110. Then, a radiation measuring device 120 measures the amount of X-rays or beta rays transmitted through the electrode tab 20. Based on this measurement, if the amount of X-rays or beta rays measured at a portion within the electrode tab shows a decrease of a predetermined threshold or more compared to a reference value, a defect is identified.

[0077] The emission of X-rays or beta rays and the measurement of their quantities can be repeatedly performed at multiple locations within the electrode terminal 20 by moving the radiation emitting device / radiation measuring device relative to the electrode terminal 20.

[0078] This inspection method can be performed after the electrode terminals are formed by welding multiple single-layer electrode terminals of the corresponding unit electrode individual to form the electrode assembly.

[0079] Preferably, the inspection can be performed after the lead wire has been soldered onto the electrode tab.

[0080] While specific embodiments have been shown and described herein, those skilled in the art will appreciate that various alternatives and / or equivalent implementations exist. It should be understood that the exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing overview and detailed description will provide those skilled in the art with a convenient roadmap for implementing at least one exemplary embodiment, and it should be understood that various changes can be made to the function and arrangement of the elements described in the exemplary embodiments without departing from the scope set forth in the appended claims. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.

[0081] List of reference numerals in the attached figures

[0082] 10 Electrode Assembly

[0083] 20 electrode connectors

[0084] Defects in 30 electrode terminals

[0085] 100 Inspection Device

[0086] 110 Radiation Emitting Device

[0087] 120, 120a, 120b, 120c radiation measuring devices

[0088] 130 processor

[0089] 140 Controller

[0090] 150-1 and 150-2 mobile systems

[0091] 160, 160-1, 160-2, 160-3 sensors

[0092] 300 Conveyor

[0093] 310 loudspeakers

[0094] 320 Anvil

Claims

1. An inspection apparatus for detecting defects in an electrode tab of an electrode assembly, wherein, The electrode connector is disposed at the longitudinal end of the electrode assembly, and the inspection device includes: A radiation emitting device configured to emit X-rays or beta rays toward the electrode terminals; A radiation measuring device, wherein the radiation measuring device is arranged opposite to the radiation emitting device such that the electrode terminals are positioned between them, wherein the radiation measuring device is configured to measure the amount of X-rays or beta rays transmitted through the electrode terminals; A processor configured to process a signal corresponding to the measured amount of the x-ray or beta ray, and to determine a defect if the amount of the x-ray or beta ray measured at a portion within the electrode tab shows a decrease of a predetermined threshold or more compared to a reference value.

2. The inspection device of claim 1, wherein, The reference value is the average amount of the X-rays or β-rays measured at adjacent portions within the electrode terminals.

3. The inspection device of claim 1, wherein, The reference value is the user-preset expected amount of the X-ray or the β-ray.

4. The inspection apparatus according to any one of claims 1 to 4, further comprising a controller configured to repeatedly perform inspections at multiple locations within the electrode terminals by moving the radiation emitting device / radiation measuring device relative to the electrode terminals.

5. The inspection device according to claim 4, wherein The radiation emitting device / radiation measuring device is movable relative to the electrode terminals at least in the longitudinal direction of the electrode assembly.

6. An inspection method for detecting defects in an electrode tab of an electrode assembly, wherein, The electrode connector is disposed at the longitudinal end of the electrode assembly, and the inspection method includes: 1) X-rays or beta rays are emitted from the radiation emitting device toward the electrode terminals; 2) The amount of X-rays or β-rays transmitted through the electrode terminals is measured by a radiation measuring device; 3) If the amount of X-rays or β-rays measured at a portion within the electrode tab shows a decrease of a predetermined threshold or more compared to a reference value, a defect is identified.

7. The inspection method according to claim 6, in, The reference value is the average amount of the X-rays or β-rays measured at adjacent portions within the electrode terminals.

8. The inspection method according to claim 6, wherein, The reference value is the user-preset expected amount of the X-ray or the β-ray.

9. The inspection method according to any one of claims 6 to 8, in, Steps 1) and 2) are repeatedly performed at multiple locations within the electrode terminals by moving the radiation emitting device / radiation measuring device relative to the electrode terminals.

10. The inspection method according to claim 9, in, The radiation emitting device / radiation measuring device is movable relative to the electrode terminals at least in the longitudinal direction of the electrode assembly.

11. The inspection method according to any one of claims 6 to 10, wherein, An inspection is performed after the electrode terminals are formed by welding multiple single-layer electrode terminals that form the respective electrode sheets of the electrode assembly.

12. The inspection method according to claim 11, wherein, An inspection is performed after the leads are soldered onto the electrode terminals.

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