Battery tab welding detection device, battery production equipment and battery production line

Abstract

The invention discloses a battery tab welding detection device, battery production equipment and a battery production line. The battery tab welding detection device comprises a conveying mechanism and a resistance measuring mechanism, the conveying mechanism is used for conveying welded pole pieces and tabs, and the resistance measuring mechanism is used for measuring the pole pieces and the tabs in the conveying process and detecting whether cold joint exists in the pole pieces and the tabs or not according to the measured resistance value. The whole detection process does not affect the transportation of the battery pole piece to the next process, and the whole detection process is automatic, so that material waste and increase of labor cost caused by manual detection are avoided.

Description

Technical Field

[0001] The present application relates to the field of battery production, and specifically to a battery tab welding detection device, battery production equipment and a battery production line. Background Art

[0002] With the rapid development of the lithium battery industry, the demand of the power battery industry has shifted from "having or not" to "higher quality": faster charging and higher safety factor. Among them, battery safety performance is even more crucial for electric vehicle users. The use of composite material pole piece substrates is a major innovation in promoting "battery safety". The pole piece substrate is a conductive layer between the active materials of the battery. The composite material substrate is based on non-metallic PET (Polyethylene Terephthalate) or PE (Polyethylene) material with a metal foil layer on the outside.

[0003] When using composite substrates, the tabs are welded to both sides of the electrode using ultrasonic roll welding to create a conductive structure that allows current to be conducted or received. Tab weld strength is a critical quality parameter in this process. A weak weld can lead to safety and quality risks such as insufficient tab current capacity, cracking in the weld mark, and even tab detachment. Therefore, timely and effective inspection of tab weld quality is a pressing issue. Summary of the Invention

[0004] In view of the above problems, the present application provides a battery tab welding detection device, battery production equipment and battery production line, which can detect in real time whether there are welding quality problems such as cold welding between the electrode sheets and the tabs.

[0005] In the first aspect, the present application provides a battery tab welding detection device, including a conveying mechanism and a resistance measuring mechanism. The conveying mechanism is used to convey the welded pole pieces and tabs, and the resistance measuring mechanism is used to measure the pole pieces and tabs being conveyed, and detect whether there is a cold weld on the pole pieces and tabs based on the measured resistance value.

[0006] In the technical solution of the embodiment of the present application, the resistance measurement mechanism continuously measures the electrode and tab during transportation and monitors the continuously measured resistance values ​​in real time. If the measured resistance values ​​show continuous abnormalities, it is determined that there is a cold weld at the electrode and tab weld. Compared with manual inspection, the technical solution of the embodiment of the present application saves time, labor and materials, and achieves real-time detection of the entire electrode and tab welding process, effectively avoiding the output of defective products.

[0007] In some embodiments, the resistance measurement mechanism includes probes configured to electrically contact the tabs on either side of the electrode sheet in the direction of travel, connecting the electrode sheet and the tabs to form a resistance measurement loop. The weld between the electrode sheet and the tab is within the resistance measurement loop, enabling the resistance measurement mechanism to measure the resistance value of the weld between the electrode sheet and the tab.

[0008] In some embodiments, the resistance measuring mechanism further comprises a pressing member for pressing the probe against the tab, so as to ensure that the probe is in continuous contact with the tab during the transportation of the electrode sheet and the tab.

[0009] In some embodiments, the resistance measuring mechanism further comprises a probe base, the probe base being provided with a limiting groove for limiting the position of the probe, and / or a retaining structure within the limiting groove for preventing the probe from escaping the limiting groove. The limiting groove limits the direction and amplitude of movement of the probe, preventing the probe from deviating from its position and separating from the tab, and the retaining structure within the limiting groove prevents the probe from escaping from the probe base.

[0010] In some embodiments, the pressing member includes a spring in a compressed state, one end of the spring abutting the probe and the other end abutting the probe base. The compressed spring always applies pressure to the probe toward the tab, ensuring that the probe always abuts the tab.

[0011] In some embodiments, the probe base is provided with an adjusting member for adjusting the pressing force of the pressing member. When the pressing force provided by the pressing member is insufficient to keep the probe in contact with the tab, the adjusting member increases the pressing force of the pressing member, thereby increasing the force applied by the pressing member on the probe and ensuring that the probe and the tab do not separate.

[0012] In some embodiments, the adjustment member includes an adjustment bolt, and the probe base is provided with a threaded hole that mates with the adjustment bolt. A compression member is disposed between the adjustment bolt and the probe. By engaging the adjustment bolt with the threaded hole in the probe base, the adjustment bolt can be rotated to change its position. The compression member is disposed between the adjustment bolt and the probe. During the adjustment bolt position change, pressure is applied to the compression member, which transmits the pressure to the probe, pressing the probe against the tab, thereby ensuring continuous contact between the probe and the tab.

[0013] In some embodiments, two sets of probes are provided, each of which contacts the tabs on either side of the electrode sheet in the conveying direction. A first adjusting member and a second adjusting member are provided on the probe base at positions corresponding to the two sets of probes, respectively, to adjust the pressing force of the corresponding pressing members of the two sets of probes. Based on the contact conditions between the two sets of probes and the tabs, the first adjusting member and the second adjusting member independently adjust the two sets of probes, ensuring that the two sets of probes can be adjusted independently without interfering with each other when they are in different states.

[0014] In some embodiments, the conveying mechanism includes a drive roller for tensioning and conveying the welded electrode piece and electrode tab. The welded electrode piece and electrode tab are tightly attached to the surface of the drive roller. During the rotation of the drive roller, the electrode piece and electrode tab are driven by static friction.

[0015] In some embodiments, the battery tab welding detection device further includes a clamping mechanism, which is used to press the pole piece and the pole tab being transported onto the conveying mechanism to prevent the conveying mechanism, the pole piece and the pole tab from slipping.

[0016] In some embodiments, the clamping mechanism includes a clamping roller, the surface of which abuts against the surface of the pole piece. The clamping roller and the drive roller sandwich the pole piece and the pole tab. The clamping roller applies pressure to increase the static friction between the drive roller and the pole piece, thereby preventing slippage between the pole piece and the drive roller.

[0017] In some embodiments, the tab weld detection device further includes a bracket and an adjustment mechanism. The bracket is used to support the resistance measuring mechanism and the clamping mechanism. The adjustment mechanism is used to adjust the position of the bracket relative to the conveying mechanism, thereby adjusting the position of the clamping mechanism and the resistance measuring mechanism relative to the electrode sheet and the tab. By adjusting the adjustment mechanism, the position of the clamping mechanism and the resistance measuring mechanism relative to the electrode sheet and the tab is controlled, thereby controlling the clamping mechanism to press and separate the electrode sheet and the tab, and controlling the resistance measuring mechanism to measure and disconnect the electrode sheet and the tab.

[0018] In some embodiments, the probe is a graphite probe. Graphite has strong conductivity and soft texture, which can ensure a resistance measurement loop path while reducing scratches on the tab.

[0019] In a second aspect, the present application provides a battery production device, which includes the battery tab welding detection device in the above embodiment.

[0020] In a third aspect, the present application provides a battery production line, which includes the battery tab welding detection device in the above embodiment.

[0021] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0023] Figure 1 This is a schematic structural diagram of a battery tab welding detection device according to some embodiments of the present application;

[0024] Figure 2 This is a schematic diagram of the structure of the battery tab welding detection device in the Y direction according to some embodiments of the present application;

[0025] Figure 3 This is a schematic diagram of the structure of the battery tab welding detection device in the Y direction according to some embodiments of the present application;

[0026] Figure 4 for Figure 1 Enlarged view of point A in the middle;

[0027] Figure 5 for Figure 2 Schematic diagram of the cross-sectional structure along the cutting line BB;

[0028] Figure 6 for Figure 5 Enlarged view of point C in the middle;

[0029] Figure 7 for Figure 3 Schematic diagram of the cross-sectional structure along the cutting line BB;

[0030] Figure 8 for Figure 7 Enlarged view of point D in the middle;

[0031] The accompanying drawings in the specific implementation manner are as follows:

[0032] 100. Battery tab welding detection device;

[0033] 200, pole piece;

[0034] 300, tab; 301, left tab; 302, right tab;

[0035] 400, welding mark; 401, left welding mark; 402, right welding mark;

[0036] 10. Conveying mechanism;

[0037] 11. Driving roller; 12. Driving roller fixing frame;

[0038] 20. Resistance measuring mechanism;

[0039] 21. Probe; 22. Probe base; 23. DC resistance tester; 24. Lead wire; 25. Pressing piece;

[0040] 211, first probe; 212, second probe;

[0041] 221, limiting groove; 2211, anti-slip structure;

[0042] 222, adjusting member; 2221, first adjusting member; 2222, second adjusting member;

[0043] 223. Install the nut;

[0044] 30. Pressing mechanism; 31. Pressing roller; 32. Driving cylinder;

[0045] 40. Bracket; 41. Adjustment mechanism;

[0046] 411. Slider; 412. Slide rail. DETAILED DESCRIPTION

[0047] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0049] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0050] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0052] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0053] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0054] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0055] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power stations, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of power batteries continue to expand, market demand is also growing.

[0056] A battery cell is the smallest unit that makes up a battery. In a battery structure, there can be multiple battery cells, and multiple battery cells can be connected in series, in parallel, or in a mixed connection. Mixed connection means that multiple battery cells are connected both in series and in parallel. Multiple battery cells can be directly connected in series, in parallel, or in a mixed connection, and then the whole composed of multiple battery cells is accommodated in a box. Of course, the battery can also be in the form of a battery module in which multiple battery cells are first connected in series, in parallel, or in a mixed connection, and the multiple battery modules are then connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in a box. The battery can also include other structures. For example, the battery can also include a busbar component for achieving electrical connection between multiple battery cells.

[0057] Each battery cell can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell can be cylindrical, flat, rectangular, or in other shapes.

[0058] The structure of a battery cell typically includes end caps, a housing, an electrode assembly, and other functional components. The electrode assembly is the component within the battery cell where the electrochemical reaction occurs, and there may be one or more electrode assemblies placed within the housing. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator, which is typically positioned between the positive and negative electrodes. Battery cells primarily rely on the movement of metal ions between the positive and negative electrodes to function.

[0059] Among them, the positive electrode plate includes a positive electrode current collector (usually called a positive electrode plate substrate) and a positive electrode active material layer coated on the surface of the positive electrode current collector. The positive electrode tab is cut from the positive electrode current collector that is not coated with the positive electrode active material layer. Generally, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode plate includes a negative electrode current collector (usually called a negative electrode plate substrate) and a negative electrode active material layer coated on the surface of the negative electrode current collector. The negative electrode tab is cut from the negative electrode current collector that is not coated with the negative electrode active material layer. Generally, in lithium-ion batteries, the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the diaphragm can be PP (polypropylene) or PE, etc.

[0060] The development of battery technology must take into account many factors at the same time, such as performance parameters such as energy density, discharge capacity, and charge and discharge rate. In addition, safety must also be considered.

[0061] The use of composite pole piece substrates is a major innovation in promoting battery safety. The pole piece substrate serves as the conductive layer between the battery's active materials. Composite substrates consist of a non-metallic PET or PE base coated with aluminum foil. Flame retardants can be added to the non-metallic core layer of the composite substrate to reduce the possibility of spontaneous combustion.

[0062] When using a composite material substrate, the tabs need to be welded on both sides of the electrode by ultrasonic roll welding. The principle is to use ultrasonic roll welding technology to electrically connect the aluminum / copper foil tabs to the composite material substrate. The tab welding strength is an important quality parameter of this process. If there is a cold weld, it will lead to safety and quality risks such as insufficient tab current capacity, cracking of the weld mark, and even tab detachment. Manual sampling can be used, that is, sampling once at the beginning and end of the roll, manually cutting and tearing the weld mark, and checking the remaining weld mark to determine whether there is a cold weld. This manual inspection method is prone to abnormal material outflow in the roll, and is labor-intensive, time-consuming, and material-intensive.

[0063] Based on the above considerations, the applicant designed a battery tab welding detection device, which determines whether there is a cold weld by measuring the resistance value at the welding point between the pole piece and the tab during the pole piece production process. It can detect whether there is a cold weld in the welding of the pole piece and the tab in real time throughout the entire line.

[0064] Whether it's a positive or negative electrode substrate, depending on the needs of the final product, you can generally have single-sided or double-sided tabs in the active material coating area of ​​the electrode. Regardless of whether it's single-sided or double-sided, space for cutting the tabs needs to be reserved on both sides of the electrode substrate. The difference between the two is that single-sided tabs require the electrode sheet to be split in the middle along the width direction, dividing the active material-coated electrode sheet into two parts, while double-sided tabs do not require the electrode sheet to be split in the middle.

[0065] Considering that this application involves a composite electrode substrate, whether it is a single-sided or double-sided electrode, it is necessary to pre-weld the electrode tabs on both sides of the electrode. The subsequent determination of whether the composite electrode needs to be split in the middle can be made based on actual product requirements. As for the coating area and coating amount of the active material on the electrode substrate, these are pre-set according to the requirements of different products.

[0066] The pole tab to be tested in this application refers to the entire pole tab to be cut after the metal foil is welded to the pole piece and before the pole tab is die-cut, that is, the complete metal foil on both sides of the pole piece, so that the resistance value can be continuously measured during the movement of the pole piece.

[0067] The battery tab welding detection device of the present application is suitable for detecting the welding tabs of the electrode substrate of the verification material during the battery production process, and can also be used in similar process that requires detecting the welding quality of two components.

[0068] Please refer to Figure 1 and Figure 2 The present invention provides a battery tab welding detection device 100, comprising a conveying mechanism 10 and a resistance measuring mechanism 20. The conveying mechanism 10 is used to convey welded electrode sheets 200 and tabs 300. The resistance measuring mechanism 20 is used to measure the electrode sheets 200 and tabs 300 being conveyed, and detect whether there is a cold weld in the electrode sheets 200 and tabs 300 based on the measured resistance values.

[0069] After the composite substrate is coated with the active material in the coating process, the electrode 200 is formed. It should be noted that the active material does not completely cover the surface of the electrode 200. Welding positions with the tabs 300 need to be reserved on both sides of the electrode 200. The tabs 300 can be connected to the electrode 200 by ultrasonic roll welding or other methods. After the electrode 200 and the tab 300 are welded, they are wound into a roll and prepared to enter the next process. The conveying mechanism 10 conveys the welded electrode 200 and tab 300 rolls to the next process, ensuring the continuity of the battery cell production process.

[0070] The conveying mechanism 10 can be a roller drive mechanism. The rolled material of the welded electrode sheet 200 and the electrode tab 300 is driven by the roller and unrolled against the roller surface. This allows the electrode sheet 200 and the electrode tab 300 to move at a controllable speed and position, thereby improving the stability of the moving state. The battery tab welding inspection device 100 inspects the unrolled and continuously moving electrode sheet 200 and the electrode tab 300.

[0071] During the production of the battery cell, the pole piece 200 is in a strip-shaped structure after the coating process is completed. After the pole piece 200 and the pole tab 300 are welded, they are also in a strip-shaped structure. The pole piece 200 and the pole tab 300 are transported along the length direction of the pole piece 200. The specific transport direction is along the X direction, that is, Figure 1 The direction of the arrow.

[0072] When the welded electrode piece 200 and electrode tab 300 are being transported by the transport mechanism 10 , the resistance measuring mechanism 20 measures the resistance of the electrode piece 200 and electrode tab 300 .

[0073] The resistance measuring mechanism 20 may include, for example, a DC resistance tester 23. The DC resistance tester 23 determines the resistance value of the conductor by applying voltage to the conductor and measuring the current passing through the conductor. During the measurement process, the DC resistance tester 23 forms a resistance measurement loop with the conductor to be measured. In the present application, the conductor to be measured is the electrode 200 and the tab 300 during the transportation process, as well as the weld mark 400 formed at the welding point between the electrode 200 and the tab 300. Because the electrode 200 and the tab 300 are both made of relatively standard materials, the resistance values ​​at different positions during the transportation process are relatively small. Therefore, the only factor affecting the change in the resistance value of the entire resistance measurement loop is the change in the resistance value of the weld mark 400 at the welding point. Therefore, it is possible to determine whether there is a cold weld between the electrode 200 and the tab 300 based on the abnormal resistance value.

[0074] A continuous weld mark 400 is formed at the welding point between the electrode 200 and the electrode tab 300. At the weld mark 400, the metal layer on the surface of the composite substrate of the electrode 200 and the electrode tab 300 made of metal are tightly connected by welding. If there is a cold weld, the welding point is not tightly connected, and the measured resistance value of the welding point is greater than the resistance value at the point where there is no cold weld. This is used to determine whether there is a cold weld between the electrode 200 and the electrode tab 300.

[0075] During the battery cell production process, the conveying mechanism 10 drives the welded electrode 200 and the electrode tab 300 to continue to move to the next process, and the resistance measuring mechanism 20 continuously measures the resistance value of the welding point of the electrode 200 and the electrode tab 300. The detected resistance value is used to determine whether there is a cold solder joint between the electrode 200 and the electrode tab 300, thereby achieving real-time detection of the entire line. In addition, compared with manual inspection after all welding is completed, it saves time, labor and materials.

[0076] According to some embodiments of this application, optionally, please continue to refer to Figure 1 and Figure 2 The resistance measuring mechanism 20 includes a probe 21, which is used to electrically contact the pole tabs 300 on both sides of the pole piece 200 in the direction of travel, and the pole piece 200 and the pole tabs 300 are connected to form a resistance measurement loop.

[0077] The probe 21 serves as a contact member with the object to be measured in the resistance measuring mechanism 20, electrically contacts the object to be measured (contacts and establishes an electrical connection), and connects the object to be measured into the resistance measurement circuit of the resistance measuring mechanism 20. In this application, the objects to be measured are the electrode 200 in the process of movement, the tabs 300 on both sides of the electrode 200 in the direction of movement, and the weld mark 400 between the electrode 200 and the tab 300. The tip of the probe 21 is against the surface of the tabs 300 on both sides of the moving direction of the pole piece 200. The DC resistance tester 23 is connected to the probe 21 through a wire 24. The DC resistance tester 23 applies voltage to the tabs 300 through the wire and the probe 21. Therefore, the probe 21 is a good conductor of electricity. Because the probe 21 is in contact with the moving tab 300, that is, the probe 21 is in sliding contact with the tab 300, the tab 300 is copper or aluminum. In order to reduce scratches on the tab 300, the material of the probe 21 is softer than the material of the tab 300. For example, the probe 21 can be tin, lead, or graphite. The probe 21 is constructed as a rod-shaped structure including a tip, that is, a needle-shaped structure. The tip of the needle-shaped probe 21 is in contact with the tab 300.

[0078] The probe 21 may also be a cone, and the tip of the cone-shaped probe 21 contacts the tab 300. The probe 21 may also be in other shapes, which are not limited here.

[0079] Because the probe 21 needs to contact the tabs 300 on both sides of the electrode 200 in the direction of travel, the probes contacting the tabs 300 on both sides are respectively the first probe 211 and the second probe 212 . Except for the different positions, the first probe 211 and the second probe 212 are exactly the same in size and material.

[0080] When the DC resistance tester 23 applies voltage to the object being measured, the current passes through the wire 24 - the first probe 211 - the left electrode tab 301 - the left weld mark 401 - the electrode 200 - the right weld mark 402 - the right electrode tab 302 - the second probe 212 in sequence, and then returns to the DC resistance tester 23 through the wire 24. The circuit through which the current flows is the resistance measurement circuit.

[0081] Through the contact between the probe 21 and the tab 300, the resistance measuring mechanism 20 can simultaneously measure the weld marks 400 on both sides of the moving direction of the electrode 200, saving measurement time. In addition, when there is a cold weld on one side or both sides of the weld marks 400, the resistance measuring mechanism 20 can detect it.

[0082] Optionally, the tip of the probe 21 is provided with a rounded corner to prevent the tab 300 from being scratched.

[0083] According to some embodiments of the present application, optionally, please refer to Figure 5 and Figure 6 The resistance measuring mechanism 20 further includes a pressing member 25 for pressing the probe 21 against the tab 300 .

[0084] The pressing member 25 can be an elastic member, which relies on its own elastic force to press the probe 21 against the surface of the tab 300. The elastic member itself has a self-recovery or reset function and deforms when subjected to force. The deformation of the pressing member 25 can provide a small amount of activity space for the position change of the probe 21.

[0085] The conveying process of the electrode piece 200 and the electrode tab 300 is a dynamic process. During the continuous conveying process, the electrode piece 200 and the electrode tab 300 will inevitably have a slight position shift, resulting in a change in the position of the electrode tab 300 relative to the probe 21. After the position of the electrode tab 300 relative to the probe 21 changes, the probe 21 is always pressed against the surface of the electrode tab 300 by the clamping member 25.

[0086] For example, after the tab 300 slightly changes position in the direction away from the probe 21, because the clamping member 25 continues to apply force to the probe 21, the probe 21 can change position following the position change of the tab 300 through the force applied by the clamping member 25, and maintain continuous electrical contact with the tab 300.

[0087] The pressing member 25 can not only apply pressure to the probe 21, but also provide space for the probe 21 to retract. When there are wrinkles on the surface of the tab 300, the wrinkles will interfere with or even collide with the probe 21. After the pressing member 25 is set, the wrinkles of the tab 300 are in contact with the probe 21, which will lift the probe 21, that is, drive the probe 21 to retract a certain distance. After the probe 21 is forced to change its position, force is applied to the pressing member 25, and the pressing member 25 is deformed to provide space for the position change of the probe 21, which not only ensures the continuous contact between the probe 21 and the tab 300, but also protects the probe 21 and the tab 300, avoiding the probe 21 from being broken by the wrinkles of the tab 300, and avoiding the tab 300 being scratched by the probe 21 and causing the tape to break.

[0088] The pressing member 25 presses the probe 21 against the surface of the tab 300 , ensuring that the probe 21 always maintains electrical contact with the tab 300 during the continuous transportation of the electrode piece 200 and the tab 300 .

[0089] According to some embodiments of this application, optionally, please continue to refer to Figure 5 and Figure 6 The resistance measuring mechanism 20 further includes a probe base 22 , on which a limiting groove 221 for limiting the probe 21 is provided.

[0090] The probe base 22 provides support for the probe 21, and the probe 21 is set in the limit groove 221. The limit groove 221 determines the relative position of the probe 21 and the tab 300, limits the movement direction and amplitude of the probe 21, and prevents the position of the probe 21 from shifting during the contact process between the probe 21 and the tab 300.

[0091] Preferably, an anti-detachment structure 2211 is provided in the limiting groove 221 to prevent the probe 21 from detaching from the limiting groove 221 , thereby preventing the probe 21 from detaching from the probe base 22 .

[0092] Taking the needle-shaped probe 21 as an example, specifically, the limiting groove 221 is constructed into a cylindrical shape, and the first open end of the cylindrical limiting groove 221 abuts against the probe base 22. The needle-shaped probe 21 is installed in the limiting groove 221 with the tip exposed. The second open end of the cylindrical limiting groove 221 for inserting the probe 21 is provided with an anti-slip structure 2211. The anti-slip structure 2211 is a circle of limiting bosses provided on the inner wall of the cylindrical limiting groove 221 near the second open end. Correspondingly, a limiting protrusion is provided at one end of the probe 21 located inside the limiting groove 221. The limiting protrusion cooperates with the limiting protrusion to limit the probe 21 and prevent the probe 21 from falling out of the limiting groove 221.

[0093] Preferably, the limiting groove 221 is installed on the probe base 22 through the mounting nut 223. For probes 21 of different shapes and types, the corresponding limiting groove 221 can be replaced. When the probe 21 is worn or damaged due to other reasons, the limiting groove 221 can be removed and replaced with a new probe 21.

[0094] According to some embodiments of this application, optionally, please continue to refer to Figure 5 and Figure 6 The pressing member 25 includes a spring in a compressed state, one end of the spring abuts against the probe 21 , and the other end abuts against the probe base 22 .

[0095] The compressed spring applies pressure to the probe 21, pressing the probe 21 against the surface of the tab 300, maintaining continuous contact between the probe 21 and the tab 300. When the wrinkles on the tab 300 interfere with the probe 21, the probe 21 retracts to avoid it, changing its position and compressing the spring. The compressed spring continues to compress and deform, providing space for the probe 21 to retract.

[0096] According to some embodiments of this application, optionally, please refer to Figure 7 and Figure 8 The probe base 22 is provided with an adjusting member 222 for adjusting the pressing force of the pressing member 25 .

[0097] When the clamping member 25 is fatigued and the clamping force provided by the clamping member 25 is insufficient to make the probe 21 press against the surface of the tab 300, the clamping force of the clamping member 25 is increased by adjusting the adjusting member 222, and the clamping member 25 applies more force to the probe 21 to ensure that the probe 21 continues to press against the surface of the tab 300 without separation.

[0098] According to some embodiments of this application, optionally, please continue to refer to Figure 7 and Figure 8 The adjusting member 222 includes an adjusting bolt, and a threaded hole that cooperates with the adjusting bolt is provided on the probe base 22; the pressing member 25 is arranged between the adjusting bolt and the probe 21.

[0099] By rotating the adjusting bolt, the adjusting bolt moves axially within the threaded hole, thereby changing its position. A pressing member 25 is disposed between the adjusting bolt and the probe 21. The adjusting bolt rotates toward the pressing member 25, applying pressure to the pressing member 25. The pressing member 25 transmits the pressure to the probe 21, pressing the probe 21 against the surface of the tab 300, ensuring continuous contact between the probe 21 and the tab 300.

[0100] Preferably, the tail end of the adjusting bolt is configured to fit a wrench, such as an external hexagonal or internal hexagonal, which is not specifically limited here. If it is difficult to rotate the adjusting bolt by hand, it can be adjusted with a tool such as a wrench.

[0101] According to some embodiments of the present application, optionally, please refer to Figure 7 Two groups of probes 21 are provided, and the two groups of probes 21 are in contact with the pole ears 300 on both sides of the conveying direction of the pole piece 200 respectively. The positions corresponding to the two groups of probes 21 are provided with a first adjusting member 2221 and a second adjusting member 2222 on the probe base 22, respectively, to adjust the clamping force of the clamping member 25 corresponding to the two groups of probes 21.

[0102] Because the two groups of probes 21 are in contact with the pole tabs 300 on both sides of the conveying direction of the pole piece 200 respectively, the contact conditions between the pole tabs 300 on both sides and the two groups of probes 21 are different, and the degree of wear of the two groups of probes 21 is also different. Therefore, according to the contact conditions between the two groups of probes 21 and the pole tabs 300 and the wear conditions of the two groups of probes 21, the first adjustment member 2221 and the second adjustment member 2222 independently adjust the two groups of probes 21 respectively to ensure that when the two groups of probes 21 are in different states, they can be adjusted separately without interfering with each other, thereby ensuring that both groups of probes 21 can be in continuous contact with the surface of the pole tab 300.

[0103] According to some embodiments of the present application, optionally, please refer to Figure 1 and Figure 4 The conveying mechanism 10 includes a driving roller 11 for tensioning and conveying the welded pole piece 200 and the pole tab 300 .

[0104] The welded pole piece 200 and pole tab 300 are in close contact with the surface of the driving roller 11 . During the rotation of the driving roller 11 , the pole piece 200 and pole tab 300 are driven to move by static friction.

[0105] According to some embodiments of this application, optionally, please continue to refer to Figure 1 and Figure 4 The battery tab welding detection device 100 further includes a pressing mechanism 30, which is used to press the pole piece 200 and the pole tab 300 being transported onto the conveying mechanism 10 to prevent the conveying mechanism 10 from slipping with the pole piece 200 and the pole tab 300.

[0106] The pressing mechanism 30 applies pressure to the pole piece 200 and the pole tab 300 to increase the static friction between the pole piece 200 and the pole tab 300 and the conveying mechanism 10 , thereby preventing slipping.

[0107] According to some embodiments of this application, optionally, please continue to refer to Figure 1 and Figure 4 The pressing mechanism 30 includes a pressing roller 31 , and the surface of the pressing roller 31 abuts against the surface of the pole piece 200 .

[0108] The pinch roller 31 and the conveying mechanism 10 sandwich the pole piece 200 and the pole tab 300 . The pinch roller 31 applies pressure to increase the static friction between the conveying mechanism 10 and the pole piece 200 , thereby preventing the pole piece 200 and the conveying mechanism 10 from slipping.

[0109] Preferably, the conveying mechanism 10 is a driving roller 11, and the pressing roller 31 and the driving roller 11 are both cylindrical rollers. The pressing roller 31 and the driving roller 11 are arranged in parallel to ensure that the contact area between the pressing roller 31 and the driving roller 11 is maximized. After the pressing roller 31 presses the pole piece 200 on the driving roller 11, the pressing roller 31 and the driving roller 11 remain in a pressed state, and the conveyor belt of the pole piece 200 drives the pressing roller 31 to rotate. The pressing roller 31 is in rolling contact with the pole piece 200, which can not only avoid scratching the pole piece 200 and the pole ear 300, but also further compact the active material coated on the surface of the pole piece 200.

[0110] Preferably, the clamping mechanism 30 further includes a driving cylinder 32, the cylinder body of the driving cylinder 32 is fixed by a fixing device, and the piston rod of the driving cylinder 32 is connected to the clamping roller 31. The driving cylinder 32 controls the distance between the clamping roller 31 and the conveying mechanism 10 by the extension and contraction of the piston rod. On the one hand, it can control the contact and separation of the clamping roller 31 and the conveying mechanism 10. After the clamping roller 31 and the conveying mechanism 10 are separated, it is convenient to arrange the electrode 200 and the electrode tab 300 on the conveying mechanism 10; on the other hand, after the electrode 200 and the conveying mechanism 10 slip, the clamping force of the clamping roller 31 on the conveying mechanism 10 is increased by the driving cylinder 32, thereby increasing the static friction between the electrode 200 and the conveying mechanism 10, and controlling the electrode 200 to stop slipping.

[0111] Preferably, a flexible layer is provided on the surface of the pressing roller 31 to further avoid scratching the electrode sheet 200 and the electrode tab 300 . The material of the flexible layer can be rubber or foam, etc., which is not specifically limited here.

[0112] According to some embodiments of the present application, optionally, please refer to Figure 3 and Figure 4 The battery tab welding detection device 100 also includes a bracket 40 and an adjustment mechanism 41. The bracket 40 is used to support the resistance measuring mechanism 20 and the pressing mechanism 30; the adjustment mechanism 41 is used to adjust the position of the bracket 40 relative to the conveying mechanism 10, so as to adjust the position of the pressing mechanism 30 and the resistance measuring mechanism 20 relative to the electrode 200 and the tab 300.

[0113] By adjusting the adjustment mechanism 41, the positions of the clamping mechanism 30 and the resistance measuring mechanism 20 relative to the pole piece 200 and the pole tab 300 are controlled, thereby controlling the clamping mechanism 30 to clamp and separate the pole piece 200 and the pole tab 300, and controlling the resistance measuring mechanism 20 to measure and disconnect the pole piece 200 and the pole tab 300.

[0114] Preferably, the adjusting mechanism 41 includes a slider 411, a slide rail 412 and an adjusting cylinder (not shown in the figure). The slide rail 412 is fixed by a fixing device so that the position of the slide rail 412 and the conveying mechanism 10 remain relatively fixed. The cylinder body of the adjusting cylinder is fixed on the slide rail 412, the piston rod of the adjusting cylinder is connected to the slider 411, and the slider 411 is connected to the bracket 40.

[0115] The piston rod of the regulating cylinder is extended and retracted to control the slider 411 to slide along the slide rail 412, thereby adjusting the position of the bracket 40 relative to the conveying mechanism 10, so as to adjust the position of the pressing mechanism 30 and the resistance measuring mechanism 20 relative to the electrode 200 and the electrode tab 300.

[0116] The adjustment mechanism 41 can also include a screw and nut mechanism, the nut is fixed by a fixing device and remains relatively fixed in position with the conveying mechanism 10, the screw is connected to the bracket 40, and a motor is set at the end of the screw. The motor drives the screw to rotate, and the screw moves axially relative to the nut, thereby driving the bracket 40 to move.

[0117] The adjustment mechanism 41 can also include a gear rack mechanism. The gear is fixed by a fixing device and remains relatively fixed in position with the conveying mechanism 10. The rack is connected to the bracket 40. The axle of the gear is connected to the electrode. The electrode drives the gear to rotate, and the gear drives the rack to move axially, thereby driving the bracket 40 to move.

[0118] The adjustment mechanism 41 may also be other mechanisms such as a worm gear mechanism, which is not specifically limited in this application.

[0119] According to some embodiments of the present application, the probe 21 is optionally a graphite probe, that is, the material of the probe 21 is graphite. Compared with tin and lead, graphite has the characteristics of strong conductivity, soft material, and low cost. Under the premise of ensuring the resistance measurement circuit path, it will not scratch the tab 300, and the replacement of the probe is cost-effective.

[0120] According to some embodiments of the present application, the present application also provides a battery production equipment, including the battery tab welding detection device described in any of the above solutions.

[0121] The battery production equipment provided in this application has the same advantages as the battery tab welding detection equipment provided in this application, which will not be repeated here.

[0122] According to some embodiments of the present application, the present application also provides a battery production line, comprising the battery tab welding detection device described in any of the above schemes.

[0123] The battery production line provided in this application has the same advantages as the battery tab welding detection equipment provided in this application, which will not be repeated here.

[0124] According to some embodiments of this application, please refer to Figure 1 , Figure 3 , Figure 4 , Figure 7 and Figure 8 The present application provides a battery tab welding detection device 100, which includes a conveying mechanism 10, a resistance measuring mechanism 20, a pressing roller 31, a bracket 40 and an adjustment mechanism 41, and also includes a controller and an alarm.

[0125] The conveying mechanism 10 includes a driving roller 11 and a driving roller fixing frame 12. The driving roller 11 conveys the welded electrode 200 and the electrode tab 300. The left electrode tab 301 and the electrode 200 are ultrasonically rolled to form a left weld mark 401. The right electrode tab 302 and the electrode 200 are ultrasonically rolled to form a right weld mark 402.

[0126] The resistance measuring mechanism 20 includes a DC resistance tester 23 and a probe 21. The first probe 211 contacts the left pole ear 301, and the second probe 212 contacts the right pole ear 302. The DC resistance tester 23 is connected to the first probe 211 and the second probe 212 respectively through the wire 24. In this way, a resistance measurement circuit of DC resistance tester 23 - wire 24 - first probe 211 - left pole ear 301 - left weld mark 401 - pole piece - right weld mark 402 - right pole ear 302 - second probe 212 - wire 24 - DC resistance tester 23 is formed, which is used to measure whether there is a cold solder joint between the left weld mark 401 and the right weld mark 402.

[0127] The resistance measuring mechanism 20 and the pressure roller 31 are supported by a bracket 40 . The adjustment mechanism 41 adjusts the position of the bracket 40 , thereby adjusting the position of the resistance measuring mechanism 20 and the pressure roller 31 relative to the conveying mechanism 10 .

[0128] The regulating mechanism 41 controls the contact and pressing of the pressing roller 31 and the driving roller 11, thereby pressing the electrode 200 and the electrode tab 300. The driving roller 11 is driven to rotate by the motor, and the welded electrode 200 and the electrode tab 300 are driven to move by static friction. The pressing roller 31 can prevent the electrode 200 from slipping. After the first probe 211 and the second probe 212 respectively contact the left electrode tab 301 and the right electrode tab 302, the DC resistance tester 23 measures the resistance of the left weld mark 401 and the right weld mark 402 through the resistance measurement circuit during the transportation of the electrode 200. The resistance curve measured by the resistance tester is used to determine whether there is a cold weld. Specifically, in order to eliminate the short-term abnormality of the resistance measurement value caused by interference, a warning value Ns for the duration of the resistance abnormal state is set. If the continuous abnormal resistance time is greater than Ns, it is determined that there is a cold weld. At this time, the DC resistance tester 23 sends a resistance abnormality signal to the controller, and the controller controls the driving mechanism to stop. The controller also controls the alarm to send an alarm signal.

[0129] Specifically, the resistance measurement mechanism includes a probe base 22, which is provided with a limiting groove 221 for mounting and limiting the position of the probe 21. The probe 21 is restricted to move only along the axial direction of the probe 21 within the limiting groove 221. A spring serving as a pressing member 25 is also contained within the limiting groove 221. The spring is in a compressed state and continuously applies force toward the tab 300 to the probe 21, ensuring continuous contact between the probe 21 and the tab 300. In addition, if the tab 300 becomes wrinkled or there is tape on the surface of the tab 300, which increases the thickness of the tab 300, the probe 21 is lifted and retracted to prevent the probe 21 from scratching or damaging the tab 300, resulting in a breakage of the tab. The probe base 22 is also provided with an adjustment member 222. When the probe 21 wears, the adjustment member 222 increases the pressure of the spring. When the spring pressure increases, the pressing force on the probe 21 increases, that is, the length of the probe 21 extending from the limit groove 221 is increased, ensuring continuous contact between the probe 21 and the tab 300. Specifically, the adjustment member is an adjustment bolt. The probe base 22 is provided with a threaded hole that cooperates with the adjustment bolt. The axial movement of the adjustment member can be adjusted by rotating the adjustment bolt.

[0130] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery tab welding detection device, characterized in that: include: Conveying mechanism, used to convey the welded pole pieces and pole ears; and The resistance measuring mechanism is used to measure the electrode piece and the electrode tab during transportation, and detect whether there is a cold solder joint between the electrode piece and the electrode tab based on the measured resistance value.

2. The battery tab welding detection device according to claim 1, characterized in that: The resistance measuring mechanism includes a probe, which is used to electrically contact the pole tabs on both sides of the moving direction of the pole piece, respectively, to connect the pole piece and the pole tabs to form a loop.

3. The battery tab welding detection device according to claim 2, characterized in that: The resistance measuring mechanism further includes a pressing member for pressing the probe against the electrode tab.

4. The battery tab welding detection device according to claim 3, characterized in that: The resistance measuring mechanism further comprises a probe base, wherein the probe base is provided with a limiting groove for limiting the position of the probe, and / or the limiting groove is provided with an anti-detachment structure for preventing the probe from escaping from the limiting groove.

5. The battery tab welding detection device according to claim 4, characterized in that: The pressing member includes a spring in a compressed state, one end of the spring abuts against the probe, and the other end abuts against the probe base.

6. The battery tab welding detection device according to claim 4, characterized in that: The probe base is provided with an adjusting member for adjusting the pressing force of the pressing member.

7. The battery tab welding detection device according to claim 6, characterized in that: The adjusting member includes an adjusting bolt, and the probe base is provided with a threaded hole matched with the adjusting bolt; the pressing member is arranged between the adjusting bolt and the probe.

8. The battery tab welding detection device according to claim 6, characterized in that: Two groups of probes are provided, and the two groups of probes are in contact with the pole ears on both sides of the pole piece conveying direction respectively. The positions corresponding to the two groups of probes are provided with a first adjusting member and a second adjusting member on the probe base respectively, for adjusting the clamping force of the clamping members corresponding to the two groups of probes respectively.

9. The battery tab welding detection device according to any one of claims 1 to 8, characterized in that: The conveying mechanism includes a driving roller for tensioning and conveying the welded pole piece and the pole tab.

10. The battery tab welding detection device according to any one of claims 1 to 8, characterized in that: The battery tab welding detection device further includes a pressing mechanism, which is used to press the pole piece and the pole tab being conveyed onto the conveying mechanism to prevent the conveying mechanism, the pole piece and the pole tab from slipping.

11. The battery tab welding detection device according to claim 10, characterized in that: The pressing mechanism includes a pressing roller, and a surface of the pressing roller abuts against a surface of the pole piece.

12. The battery tab welding detection device according to claim 10, characterized in that: The tab cold welding detection device further comprises: A bracket, used for supporting the resistance measuring mechanism and the pressing mechanism; The adjusting mechanism is used to adjust the position of the bracket relative to the conveying mechanism, so as to adjust the position of the pressing mechanism and the resistance measuring mechanism relative to the pole piece and the pole ear.

13. The battery tab welding detection device according to any one of claims 2 to 8, characterized in that: The probe is a graphite probe.

14. A battery production device, characterized in that: It comprises the battery tab welding detection device as described in any one of claims 1-13.

15. A battery production line, characterized in that: It comprises the battery tab welding detection device as described in any one of claims 1-13.

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