Electrode sheet die-cutting method and electrode sheet die-cutting device

Abstract

An electrode sheet die-cutting method and an electrode sheet die-cutting device. The electrode sheet die-cutting method comprises: providing an electrode sheet material (900); in the process of die-cutting the electrode sheet material (900) by die-cutting units (120) to generate an electrode sheet (901) having a single-cell electrode sheet length, a defect detection unit performing defect detection on the electrode sheet material (900), wherein the electrode sheet (901) having the single-cell electrode sheet length is indicated by a mark (911) die-cut on the electrode sheet (901); and in response to detection of the presence of a defect (990) on the electrode sheet material (900) by the defect detection unit, depending on the position where the detected defect (990) is located on a first electrode sheet which is undergoing die-cutting, terminating the die-cutting of the first electrode sheet, and starting die-cutting of a second electrode sheet.

Description

Pole piece die-cutting method and pole piece die-cutting device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 16, 2024, with application number 202410057769.0 and invention name “Pole piece die-cutting method and pole piece die-cutting device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of batteries, and in particular to a pole piece die-cutting method and a pole piece die-cutting device. Background Art

[0003] In the process of producing the pole pieces used to form the battery cells, it is usually necessary to inspect the appearance and size of the pole pieces. In the event that a defect is detected in the pole piece, the pole piece can be marked so that bad products can be eliminated to avoid adverse effects on the subsequent battery cell manufacturing. With the development of the industry, the length of the pole piece corresponding to a single battery cell (single-cell pole piece length) is also increasing. In this way, once a defect is detected in the pole piece, even if it is only one defect, it may cause the entire pole piece used for the battery cell to be scrapped, resulting in serious waste.

[0004] Summary of the Invention

[0005] In view of the above problems, the present application provides a pole piece die-cutting method and a pole piece die-cutting device, which can alleviate the waste problem caused by the existence of defects in the pole piece.

[0006] In a first aspect, the present application provides a pole piece die-cutting method, comprising: providing pole piece material; performing defect detection on the pole piece material by a defect detection unit during the process of die-cutting the pole piece material by a die-cutting unit to produce a pole piece having the length of a single-cell pole piece, wherein the pole piece having the length of a single-cell pole piece is indicated by a mark die-cut on the pole piece; in response to the defect detection unit detecting the presence of a defect on the pole piece material, depending on the position of the detected defect on the first pole piece being die-cut, terminating the die-cutting of the first pole piece and restarting the die-cutting of the second pole piece.

[0007] In the technical solution of the embodiment of the present application, defects are detected on the electrode material. When defects are detected, it is determined whether the electrode material needs to be reset and re-cut according to the location of the defect. If the conditions are met, the die-cutting of the first electrode being die-cut is terminated and the die-cutting of the second electrode is restarted, that is, reset and re-cutting is performed to reduce the waste of electrode material.

[0008] In some embodiments, in response to a defect detected on the pole piece material by a defect detection unit, die-cutting of the first pole piece is terminated and die-cutting of the second pole piece is restarted depending on the position of the detected defect on the first pole piece being die-cut. The method includes: in response to a defect detected on the pole piece material by the defect detection unit, determining a first distance in a first direction between the defect and a preset position on the first pole piece, wherein the first direction is the direction of movement of the pole piece material during the die-cutting process; comparing the first distance with a preset length threshold; and if the first distance is less than the preset length threshold, terminating the die-cutting of the first pole piece, and performing die-cutting of the second pole piece on the pole piece material by the die-cutting unit.

[0009] In some embodiments, the pole piece die-cutting method further includes: when the first distance is greater than or equal to the preset length threshold, the marking unit marks the first pole piece as defective.

[0010] In some embodiments, the pole piece die-cutting method also includes: when the first distance is greater than or equal to the preset length threshold, the die-cutting unit continues to perform die-cutting on the pole piece material according to preset die-cutting parameters, wherein the preset die-cutting parameters correspond to the die-cutting parameters when no defects are detected on the pole piece material.

[0011] In some embodiments, a defect detection unit performs defect detection on the pole piece material based on the photographing of the pole piece material by a visual detection unit, and the visual detection unit includes a first visual detection unit located in front of the die-cutting unit in the first direction. When the pole piece material is a single-sided pole piece material with a pole ear die-cut on only one side perpendicular to the moving direction, the first length threshold is used as the preset length threshold, wherein the first length threshold is determined based on the total pole piece length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

[0012] In some embodiments, the first length threshold is equal to the total pole piece length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0013] In some embodiments, a defect detection unit performs defect detection on the pole piece material based on the photographing of the pole piece material by a visual detection unit, and the visual detection unit includes a first visual detection unit located in front of the die-cutting unit in the first direction. In the case that the pole piece material is a double-sided pole piece material with pole ears die-cut on both sides perpendicular to the moving direction, the pole piece die-cutting method further includes: in response to the detection of a defect on the pole piece material by the first visual detection unit, the defect detection unit determines the pole piece material area where the defect is located in the pole piece material, wherein the pole piece material includes two pole piece material areas, and the two pole piece material areas are defined by a cutting line extending along the first direction in the pole piece material, and the two pole piece material areas are respectively used to form different pole pieces; and the preset length threshold is determined according to the pole piece material area where the defect is located in the pole piece material.

[0014] In some embodiments, determining the preset length threshold based on the pole piece material area where the defect is located in the pole piece material includes: when the defect is distributed in the two pole piece material areas, using the first length threshold as the preset length threshold, wherein the first length threshold is determined based on the total pole piece length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0015] In some embodiments, the first length threshold is equal to the total pole piece length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0016] In some embodiments, the die-cutting unit includes a first die-cutting unit and a second die-cutting unit. When the first distance is less than the preset length threshold, the die-cutting of the first pole piece is terminated, and the die-cutting unit performs the die-cutting of the second pole piece on the pole piece material, including: for each pole piece material area in the two pole piece material areas, the die-cutting of the first pole piece is terminated, and the first die-cutting unit and the second die-cutting unit respectively perform the die-cutting of the corresponding second pole piece.

[0017] In some embodiments, when the die-cutting of two pole piece material areas of the pole piece material can be performed asynchronously, determining the preset length threshold according to the pole piece material area where the defect is located in the pole piece material includes: using the first length threshold as the preset length threshold, wherein the first length threshold is determined based on the total pole piece length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0018] In some embodiments, the first length threshold is equal to the total pole piece length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0019] In some embodiments, the die-cutting unit includes a first die-cutting unit and a second die-cutting unit. When the first distance is less than the preset length threshold, the die-cutting of the first pole piece is terminated, and the die-cutting unit performs die-cutting of the second pole piece on the pole piece material, including: terminating the die-cutting of the first pole piece on a pole piece material area where the defect exists in the two pole piece material areas, and performing die-cutting of the second pole piece on the pole piece material area by one of the first die-cutting unit and the second die-cutting unit close to the pole piece material area; and continuing to perform die-cutting on the pole piece material area according to preset die-cutting parameters by one of the first die-cutting unit and the second die-cutting unit close to the pole piece material area on the other pole piece material area where the defect does not exist in the two pole piece material areas, wherein the preset die-cutting parameters correspond to the die-cutting parameters when no defects are detected on the pole piece material.

[0020] In some embodiments, when the die-cutting of two pole piece material areas of the pole piece material can only be performed synchronously, determining the preset length threshold according to the pole piece material area where the defect is located in the pole piece material includes: when the defect is distributed in only one of the two pole piece material areas, using the second length threshold as the preset length threshold, wherein the second length threshold is determined based on the total pole piece length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0021] In some embodiments, the second length threshold is equal to half of the total length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit.

[0022] In some embodiments, the die-cutting unit includes a first die-cutting unit and a second die-cutting unit. When the first distance is less than the preset length threshold, the die-cutting of the first pole piece is terminated, and the die-cutting unit performs the die-cutting of the second pole piece on the pole piece material, including: for each pole piece material area in the two pole piece material areas, the die-cutting of the first pole piece is terminated synchronously, and the die-cutting of the corresponding second pole piece is performed synchronously by the first die-cutting unit and the second die-cutting unit respectively.

[0023] In some embodiments, a defect detection unit performs defect detection on the pole piece material based on the photographing of the pole piece material by a visual detection unit, and the visual detection unit includes a second visual detection unit located behind the die-cutting unit in the first direction. In the case that the pole piece material is a single-sided pole piece material with a pole ear die-cut on only one side perpendicular to the moving direction, the third length threshold is used as the preset length threshold, wherein, when the final position of the first pole piece being die-cut is not between the second visual detection unit and the die-cutting unit when the defect is detected, the first distance is less than the third length threshold, and when the final position of the first pole piece being die-cut is between the second visual detection unit and the die-cutting unit when the defect is detected, the first distance is greater than or equal to the third length threshold.

[0024] In some embodiments, a defect detection unit performs defect detection on the pole piece material based on the photographing of the pole piece material by a visual detection unit, and the visual detection unit includes a second visual detection unit located behind the die-cutting unit in the first direction. When the pole piece material is a double-sided pole piece material with pole ears die-cut on both sides perpendicular to the moving direction, and the die-cutting of the two pole piece material areas of the pole piece material can be performed asynchronously, the third length threshold is used as the preset length threshold, wherein the pole piece material includes two pole piece material areas, and the two pole piece material areas are defined by a cutting line extending along the first direction in the pole piece material, and the two pole piece material areas are respectively used to form different pole pieces. When the final position of the first pole piece being die-cut when the defect is detected is not between the second visual detection unit and the die-cutting unit, the first distance is less than the third length threshold, and when the final position of the first pole piece being die-cut when the defect is detected is between the second visual detection unit and the die-cutting unit, the first distance is greater than or equal to the third length threshold.

[0025] In some embodiments, the third length threshold is equal to the total length of each pole piece plus the distance in the first direction between the second defect detection position of the second visual inspection unit and the die-cutting position of the die-cutting unit minus the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece.

[0026] In some embodiments, the pole piece die-cutting method also includes: when the first distance is greater than or equal to the third length threshold, the die-cutting unit continues to perform die-cutting on the pole piece material according to preset die-cutting parameters until the die-cutting of the first pole piece is completed, and then the die-cutting unit performs die-cutting on the second pole piece on the pole piece material, wherein the preset die-cutting parameters correspond to the die-cutting parameters when no defects are detected on the pole piece material.

[0027] In some embodiments, a defect detection unit performs defect detection on the pole piece material based on the photographing of the pole piece material by a visual detection unit, and the visual detection unit includes a second visual detection unit located behind the die-cutting unit in the first direction. When the pole piece material is a double-sided pole piece material with pole ears die-cut on both sides perpendicular to the moving direction, and the die-cutting of the two pole piece material areas of the pole piece material can only be performed synchronously, the fourth length threshold is used as the preset length threshold, wherein the pole piece material includes two pole piece material areas, and the two pole piece material areas are defined by a cutting line extending in the first direction in the pole piece material, and the two pole piece material areas are respectively used to form different pole pieces, and the fourth length threshold is determined based on the total pole piece length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the second defect detection position of the second visual detection unit and the die-cutting position of the die-cutting unit.

[0028] In some embodiments, the fourth length threshold is equal to half the total length of each pole piece plus the distance in the first direction between the second defect detection position of the second visual inspection unit and the die-cutting position of the die-cutting unit minus the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece.

[0029] In the second aspect, the present application provides a pole piece die-cutting device, comprising: a visual inspection unit, which is configured to photograph the pole piece material; a defect detection unit, which is communicatively connected to the visual inspection unit, and the defect detection unit is configured to determine whether there is a defect on the pole piece material based on the image photographed by the visual inspection unit; a die-cutting unit, which is communicatively connected to the defect detection unit, and the die-cutting unit is configured to perform die-cutting of the pole piece; and a control unit, which is communicatively connected to the defect detection unit and the die-cutting unit, and the control unit is configured to terminate the die-cutting of the first pole piece and restart the die-cutting of the second pole piece in response to detecting the presence of a defect on the pole piece material, depending on the position of the detected defect on the first pole piece being die-cut.

[0030] In the pole piece die-cutting device of the embodiment of the present application, defects are detected on the pole piece material. When defects are detected, it is determined whether the pole piece material needs to be reset and re-cut according to the location of the defect. If the conditions are met, the die-cutting of the first pole piece is terminated and the die-cutting of the second pole piece is performed, that is, reset and re-cutting is performed to reduce the waste of pole piece material.

[0031] In some embodiments, the pole piece die-cutting device further includes: an identification unit, which is communicatively connected to the defect detection unit and the control unit, and the identification unit is located in front of the visual detection unit in a first direction, and the identification unit is configured to identify the pole piece as defective.

[0032] In some embodiments, the visual inspection unit includes at least one of the following: a first visual inspection unit, which is located in front of the die-cutting unit in the first direction; and a second visual inspection unit, which is located behind the die-cutting unit in the first direction.

[0033] In some embodiments, the pole piece die-cutting device further includes: a slitting unit, wherein the slitting unit is located in front of the visual inspection unit in the first direction, and the slitting unit is configured to slit the two pole piece material areas contained in the pole piece material along a slitting line extending along the first direction in the pole piece material, and the two pole piece material areas are respectively used to form different pole pieces.

[0034] In some embodiments, the die-cutting unit includes: a first die-cutting unit; and a second die-cutting unit, wherein the first die-cutting unit and the second die-cutting unit are respectively located at two ends of a second direction perpendicular to the first direction.

[0035] 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

[0036] 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:

[0037] FIG1 is a schematic structural diagram of a pole piece in some embodiments of the present application;

[0038] FIG2 is a schematic structural diagram of a pole piece die-cutting device and a pole piece in some embodiments of the present application;

[0039] FIG3 is a schematic structural diagram of a pole piece die-cutting device and pole pieces according to other embodiments of the present application;

[0040] FIG4 is a schematic structural diagram of a pole piece die-cutting device and pole pieces according to some other embodiments of the present application;

[0041] FIG5 is a schematic structural diagram of a pole piece die-cutting device and pole pieces according to some further embodiments of the present application;

[0042] FIG6 is a schematic flow chart of a pole piece die-cutting method according to some embodiments of the present application;

[0043] FIG7 is a partial flow diagram of a pole piece die-cutting method according to some embodiments of the present application;

[0044] FIG8 is a partial flow chart of a pole piece die-cutting method according to some other embodiments of the present application.

[0045] The accompanying drawings in the specific implementation manner are as follows:

[0046] 900, pole piece material; 901, pole piece; 901a, first pole piece material region; 901b, second pole piece material region; 910, pole tab; 911, mark; 990, defect;

[0047] 110. First visual inspection unit; 120. Die-cutting unit; 121. First die-cutting unit; 122. Second die-cutting unit; 130. Control unit; 140. Marking unit; 150. Second visual inspection unit; 160. Slitting unit. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] Currently, market developments indicate that power batteries (e.g., lithium batteries) are becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0057] Whether the cells in power batteries are produced based on a winding process or a stacking process, the pole pieces used in the cells need to be inspected in advance for appearance and size. In the event that a defect is detected in the pole piece, the pole piece can be marked so that before the pole piece is made into a cell, the subsequent process equipment can remove the bad products by identifying the mark to avoid adverse effects on the cell production. With the development of the industry, consumers have higher and higher requirements for battery life. In order to meet the long-term requirements, with the optimization and development of the process, the length of the pole piece corresponding to a single cell (that is, the length of the single cell pole piece or the EA length of the pole piece) is also increasing, for example, from the initial 5 meters to the current 30 meters. At the same time, in order to ensure the safety of the battery, if a defect is detected in the pole piece, even if it is only one defect, the entire pole piece with the EA length may need to be scrapped, which can easily cause serious waste.

[0058] In order to avoid the problem that the entire electrode sheet is scrapped due to the existence of a single defect, during the process of die-cutting the electrode sheet material to form an electrode sheet, reset re-cutting can be automatically performed based on the detection of defects in the electrode sheet, so as to achieve the purpose of saving materials, thereby reducing production costs and improving production efficiency at the same time. For this reason, the present application proposes an electrode sheet die-cutting method and an electrode sheet die-cutting device.

[0059] As shown in FIG. 1, the electrode sheet 901 for manufacturing an electric core can be formed by die-cutting an electrode sheet material. During the die-cutting process, the electrode sheet material can move in the direction from left (also referred to as the rear in this article) to right (also referred to as the front in this article) shown in FIG. 1, and the tab 910 is cut out at the corresponding position of the electrode sheet material by a die-cutting unit. Among them, the tab 910 can be a conductor that leads out the positive and negative electrodes from the electric core to serve as a contact point during battery charging and discharging. As shown in FIG. 1, within the range of the electrode sheet corresponding to a single electric core (that is, within the range of the length of a single-cell electrode sheet or the EA length), multiple tabs 910 can be included. According to whether the electric core is prepared based on a winding process or a stacking process, the distance setting between the tabs 910 can be different. For example, in the case of preparing an electric core by a winding process, the distance between every two adjacent tabs 910 on the electrode sheet 901 can be different. This is because as the winding process progresses, the distance between the tabs 910 in the region of the electrode sheet 901 that is farther away from the winding center needs to be set larger to achieve the desired alignment of the tabs 910. In the embodiment shown in FIG. 1, within a single EA length, the distances D1, D2, D3, …, Dn-1, and Dn between two adjacent tabs 910 can satisfy D1 < D2 < D3 < … < Dn-1 < Dn, that is, the left region of the electrode sheet 901 in FIG. 1 can be wound inside the right region of the electrode sheet 901 to form an electric core. It can be understood that when die-cutting the subsequent electrode sheet (that is, the leftmost electrode sheet shown in FIG. 1) continuously, the distance between the tabs 910 will start from Dn again and change according to the trend of Dn-1, …, D3, D2, and D1 described above. In addition, in the case of preparing an electric core based on a stacking process, the distance between every two adjacent tabs 910 on the electrode sheet can be equal, or other desired distance setting methods can also be adopted according to needs, which are not limited here. To sum up, during the process of die-cutting the electrode sheet material to form the tabs in the electrode sheet, since the distance between two adjacent tabs in the same electrode sheet may be different, once there are defects in the electrode sheet, regardless of their quantity and position, it may lead to the scrapping of the entire electrode sheet, and the intact partial area of the electrode sheet cannot be fully utilized. However, in the present application, it is desired to solve this problem by means of reset re-cutting.

[0060] In an exemplary embodiment of the present application, as shown in Figures 2 to 5, the pole piece die-cutting device may include a visual inspection unit (the first visual inspection unit 110 in Figures 2 to 5, and / or the second visual inspection unit 150 in Figures 4 and 5), a defect detection unit, a die-cutting unit (the die-cutting unit 120 in Figures 2 and 5, or the first die-cutting unit 121 and the second die-cutting unit 122 in Figures 3 and 5) and a control unit 130, which can be used to implement the pole piece die-cutting method of the present application, as will be described in detail later. It should be noted that both the first visual inspection unit 110 and the second visual inspection unit 150 are depicted in Figures 4 and 5, but it can be understood that, if necessary, only one of the first visual inspection unit 110 and the second visual inspection unit 150 can be provided in the pole piece die-cutting device.

[0061] Wherein, the visual inspection unit can be configured to photograph the pole piece material, the defect detection unit can be communicatively connected to the visual inspection unit, and the defect detection unit can be configured to determine whether there are defects on the pole piece material 900 based on the image photographed by the visual inspection unit. In some embodiments, as shown in Figures 2 to 5, the visual inspection unit may include a first visual inspection unit 110, whose shooting position is indicated by the arrow below the first visual inspection unit 110. In other embodiments, as shown in Figures 4 and 5, the visual inspection unit may include a second visual inspection unit 150, whose shooting position is indicated by the arrow below the second visual inspection unit 150. As the pole piece material moves in the direction from left (back) to right (front), the visual inspection unit can photograph the entire pole piece. Typically, the visual inspection unit can only photograph the front side of the pole piece (i.e., the side shown in Figures 2 to 5), but it can be understood that, if necessary, the visual inspection unit can also only photograph the back side of the pole piece, or photograph both the front and back sides of the pole piece. In some embodiments, the visual inspection unit may include, for example, a charge coupled device (CCD) camera, which may capture the surface to be inspected of the pole piece material 900. The defect detection unit may be communicatively connected to either the first visual inspection unit 110 or the second visual inspection unit 150, and the defect detection unit may include, for example, a processor, and analyze the image captured by the visual inspection unit to determine whether there are defects on the pole piece material.

[0062] The die-cutting unit 120 can be communicatively connected to the defect detection unit. For example, the die-cutting unit 120 can be communicatively connected to the defect detection unit directly, or can also be communicatively connected to the defect detection unit via the control unit 130 as described later. In a first direction, the die-cutting unit 120 can be located behind the first visual inspection unit 110 (or the left side as shown in Figures 2 to 5), where the first direction is the moving direction of the pole piece material 900 during the die-cutting process. In addition, the die-cutting unit 120 can be located in front of the second visual inspection unit 150 (or the right side as shown in Figures 4 and 5). The die-cutting unit 120 can be configured to perform die-cutting on the pole piece 901. In the exemplary embodiment shown in Figures 2 to 5, the position where the die-cutting unit 120 die-cuts the pole piece material 900 can be indicated by the arrow corresponding to the die-cutting unit 120 (or the first die-cutting unit 121 and the second die-cutting unit 122). That is, in the exemplary embodiments shown in Figures 2 to 5, the pole piece material 900 can move from left to right, passing through the possible second visual inspection unit 150, the die-cutting unit 120, and the possible first visual inspection unit 110 in sequence. The pole piece material 900 can first be die-cut by the die-cutting unit 120 to form structures such as the pole tab 910, and then the first visual inspection unit 110 and the defect detection unit can photograph and inspect the pole piece material 900 after die-cutting to confirm whether there are defects on the pole piece 901 obtained by die-cutting. In addition, before the pole piece material 900 is die-cut by the die-cutting unit 120, the second visual inspection unit 150 and the defect detection unit can also photograph and inspect the pole piece material 900 before die-cutting.

[0063] In some embodiments, the electrode die-cutting device can be used to die-cut a single-sided electrode material, in which a tab is only die-cut on one side perpendicular to the first direction, as shown in Figures 2 and 4. The die-cutting unit 120 can be provided on the side close to the tab to be cut.

[0064] In other embodiments, the pole piece die-cutting device can be used to die-cut bilateral pole piece materials. In the bilateral pole piece materials, pole ears need to be die-cut on both sides perpendicular to the first direction, and then the pole piece material can be cut into two parts along the cutting line extending in the first direction, thereby forming corresponding pole pieces, as shown in Figures 3 and 5. Accordingly, in some embodiments, the die-cutting unit may include a first die-cutting unit 121 and a second die-cutting unit 122, wherein the first die-cutting unit 121 and the second die-cutting unit 122 can be respectively located at the two ends of the second direction perpendicular to the first direction, that is, respectively arranged near the two edge areas extending along the first direction of the pole piece material 900, so as to achieve die-cutting of the bilateral pole piece material, thereby helping to improve the die-cutting efficiency. In some embodiments, the first die-cutting unit 121 and the second die-cutting unit 122 can operate asynchronously, that is, they can be controlled separately to achieve die-cutting of the corresponding pole piece material areas. In other embodiments, in order to simplify the control method, the first die-cutting unit 121 and the second die-cutting unit 122 can also only operate synchronously, that is, the die-cutting of the two pole piece material areas is jointly controlled, and the die-cutting is performed synchronously or stopped synchronously.

[0065] As shown in Figures 2 to 5, the pole piece die-cutting device may further include a control unit 130, which may be communicatively connected to the defect detection unit and the die-cutting unit 120. In some embodiments, the control unit 130 may be separately provided independently of the other components of the pole piece die-cutting device. Alternatively, the control unit 130 may be integrated with other components of the pole piece die-cutting device, such as the defect detection unit, the visual inspection unit or the die-cutting unit 120. The control unit 130 may be configured to terminate the die-cutting of the first pole piece and restart the die-cutting of the second pole piece in response to detecting the presence of a defect on the pole piece material 900, depending on the position of the detected defect on the first pole piece being die-cut. For example, the control unit 130 can be configured to determine a first distance in a first direction between the defect and a preset position on the first pole piece being die-cut when the defect is detected, compare the first distance with a preset length threshold, and control the die-cutting unit 120 to terminate the die-cutting of the first pole piece when the first distance is less than the preset length threshold, and control the die-cutting unit 120 to perform die-cutting on a second pole piece different from the first pole piece on the pole piece material 900, that is, to perform resetting and re-cutting of the pole piece material when the preset conditions are met, thereby avoiding waste of the pole piece material, as will be explained in detail in the part about the pole piece die-cutting method later.

[0066] In some embodiments, the control unit 130 may include a processor and a memory to participate in implementing a pole piece die-cutting method as will be described in detail later.

[0067] Among them, the processor can perform various actions and processes according to the instructions stored in the memory. Specifically, the processor can be an integrated circuit chip with signal processing capabilities. The above-mentioned processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The various methods, steps and logic block diagrams disclosed in the embodiments of the present disclosure can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc., which can be an X86 architecture or an ARM architecture, etc.

[0068] The memory may store executable instructions that, when executed by the processor, implement the pole piece die cutting method as described herein. The memory may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. The non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus random access memory (DR RAM). It should be noted that the memory of the method described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0069] In some embodiments, as shown in Figures 2 to 5, the pole piece die-cutting device may further include an identification unit 140, which may be communicatively connected to the defect detection unit and the control unit 130. In the first direction, the identification unit 140 may be located in front of the visual inspection unit, for example, in front of the first visual inspection unit 110 (i.e., on the right side as shown in Figures 2 to 5). The identification unit 140 may be configured to identify the pole pieces as defective products so that the subsequent process equipment can identify and remove the defective products through identification, thereby avoiding adverse effects on the manufacture of the battery cells. It is understandable that the identification unit 140 may identify the pole pieces with defects therein, for example, based on a variety of identification methods including visual identification, and this is not limited here.

[0070] In some embodiments, the setting position of the second visual inspection unit 150 may not be restricted or less restricted by the die-cutting unit 120, so that it is closer to the die-cutting unit 120 than the first visual inspection unit 110, so as to facilitate the determination of whether resetting and re-cutting are required, as will be explained in detail later in the pole piece die-cutting method.

[0071] In some embodiments, in particular, in a pole piece die-cutting device for processing bilateral pole piece materials, as shown in Figures 3 and 5, the pole piece die-cutting device may further include a slitting unit 160. In the first direction, the slitting unit 160 may be located in front of the visual inspection unit, for example, in front of the first visual inspection unit 110 (for example, between the first visual inspection unit 110 and the identification unit 140), and its slitting position for the pole piece is indicated by the corresponding arrow. The slitting unit 160 may be configured to separate the first pole piece material region 901a and the second pole piece material region 901b contained in the pole piece material 900 along a slitting line extending along the first direction in the pole piece material 900, so that the two pole piece material regions can be used to form corresponding pole pieces respectively.

[0072] The present application also proposes a pole piece die-cutting method. In some embodiments, the pole piece die-cutting device as described above can be used to implement the pole piece die-cutting method of the present application, or other devices can be used to implement the pole piece die-cutting method of the present application, which is not limited here.

[0073] In an exemplary embodiment of the present application, as shown in FIG2 to FIG6 , a pole piece die cutting method may include:

[0074] Step S601, providing a pole piece material;

[0075] Step S602 , during the process of die-cutting the electrode material by the die-cutting unit to produce an electrode having the length of a single-cell electrode, the defect detection unit performs defect detection on the electrode material;

[0076] Step S603 , in response to the defect detection unit detecting a defect on the pole piece material, depending on the position of the detected defect on the first pole piece being die-cut, terminating the die-cutting of the first pole piece and restarting the die-cutting of the second pole piece.

[0077] Wherein, a pole piece having a length of a single cell pole piece can be indicated by a mark die-cut on the pole piece. In some embodiments, as shown in FIG7 , in response to a defect detection unit detecting a defect on the pole piece material, depending on the position of the detected defect on the first pole piece being die-cut, terminating the die-cutting of the first pole piece and restarting the die-cutting of the second pole piece can specifically include: step S610, in response to a defect detection unit detecting a defect 990 on the pole piece material 900, determining a first distance L1 in a first direction between the defect 990 and a preset position on the first pole piece being die-cut when the defect 990 is detected; step S620, comparing the first distance L1 with a preset length threshold; and step S631, when the first distance L1 is less than the preset length threshold, terminating the die-cutting of the first pole piece, and performing the die-cutting of the second pole piece on the pole piece material by the die-cutting unit.

[0078] As described above, the first direction is the direction of movement of the electrode material during the die-cutting process, that is, the direction from left to right as shown in Figures 2 to 5. In some embodiments, the first visual inspection unit 110 can be located in front of the die-cutting unit 120 in the first direction (that is, on the right side as shown in Figures 2 to 5). Whether to terminate the die-cutting of the first electrode and perform the die-cutting of the second electrode can be determined based on whether performing reset and re-cutting (that is, restarting the die-cutting of a new electrode) can effectively save electrode material. For example, it can be determined based on the comparison result between the first distance L1 and the preset length threshold. In some embodiments, the first distance can be determined based on the number of photos taken by the visual inspection unit during the period between detecting the defect and detecting the previous mark on the electrode. The first distance L1 can reflect the length of the electrode portion that has been die-cut, and is then used to determine whether resetting and re-cutting at this time can achieve the saving of electrode material. Alternatively, in some other embodiments, other methods can be used to determine the first distance L1, which is not limited here. In addition, depending on the specific electrode die-cutting method and / or the process requirements for saving electrode material, a preset length threshold can be determined, and when the first distance L1 is less than the preset length threshold, the die-cutting of the first electrode is terminated, and the die-cutting of another second electrode different from the first electrode is performed to achieve the purpose of saving electrode material. The determination method of the first distance L1 and the preset length threshold will be described in detail later. In addition, as described above, the die-cutting of the electrode by the die-cutting unit 120 on the electrode material 900 can specifically include the die-cutting unit 120 cutting at a preset interval in the edge area extending along the first direction of the electrode material 900 to form the electrode ear 910 of the electrode 901. In some embodiments, as shown in Figures 2 to 5, the die-cutting of the pole piece performed on the pole piece material 900 by the die-cutting unit 120 can also include the die-cutting unit 120 cutting on at least one of the first pole ear 910 and the last pole ear 910 of the pole piece 901 to form a pole piece mark 911, which can be used to determine the start and end of the pole piece 901 in the subsequent battery cell manufacturing process, thereby helping to correctly manufacture the battery cell.

[0079] In some embodiments, as shown in Figures 2 to 5 and 8, the electrode die-cutting method may further include: Step S632, when the first distance is greater than or equal to a preset length threshold, the identification unit 140 identifies the first electrode as defective. In this way, during the battery cell manufacturing process, defective electrode sheets can be removed by subsequent process equipment based on the defective identification, thereby ensuring the reliability of battery cell manufacturing.

[0080] In some embodiments, as shown in Figures 2 to 5 and 8, the pole piece die-cutting method may further include: step S633, when the first distance L1 is greater than or equal to the preset length threshold, the die-cutting unit 120 continues to perform die-cutting on the pole piece material according to the preset die-cutting parameters. The preset die-cutting parameters may correspond to the die-cutting parameters when no defects are detected on the pole piece material 900. That is, when the first distance is greater than or equal to the preset length threshold, it indicates that there is no need to perform reset and re-cutting, or it is necessary to wait until the die-cutting of the first pole piece is completed before reset and re-cutting can be performed. At this time, the original die-cutting process can be continued. It is understandable that in some embodiments, the order between step S632 and step S633 may not be limited to the order shown in Figure 8. They may be performed one after another, or simultaneously, or only one of step S632 and step S633 may be performed. There is no limitation here.

[0081] The following will specifically describe how to determine the first distance and the preset length threshold according to the pole piece material properties and the pole piece die-cutting method, and perform the reset and re-cutting operation accordingly.

[0082] In some embodiments, as shown in FIG2 , when the electrode material is a single-sided electrode material, the first length threshold Lt1 can be used as a preset length threshold. For example, the first length threshold is determined based on the total length of each electrode, the distance in the first direction between the preset position on the first electrode and the starting position of the first electrode, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit. In some embodiments, the first length threshold Lt1 is equal to the total length L0 of each electrode (i.e., the EA length of the electrode) minus the distance Ls in the first direction between the preset position on the first electrode and the starting position of the first electrode minus the distance Lc1 in the first direction between the first defect detection position of the first visual inspection unit 110 and the die-cutting position of the die-cutting unit 120, i.e., Lt1=L0-Ls-Lc1. The preset position on the first electrode can be selected as needed, and can be calculated as long as the distance in the first direction between it and the starting position of the first electrode is known. When the preset position is in front of the defect 990, L1 takes a positive value, and when the preset position is behind the defect 990, L1 takes a negative value. In a specific example, for the convenience of calculation, the starting position of the first pole piece (such as represented by the rightmost pole ear 910 with a mark 911 in the first pole piece, or the starting position of the first pole ear of the first pole piece in the first direction) itself can be used as the preset position on the first pole piece, so that Ls=0, that is, the above formula evolves into Lt1=L0-Lc1. However, it can be understood that in some other embodiments, other positions on the pole piece that are convenient for positioning can also be used as preset positions. In this case, Ls≠0, but the first length threshold can still be determined according to Lt1=L0-Ls-Lc1.

[0083] As shown in FIG2 , in the case of L1<Lt1, the die-cutting of the first pole piece can be terminated, and the die-cutting unit 120 performs the die-cutting of the second pole piece on the pole piece material, which can save the pole piece material length Lt1-L1 compared to the case where the reset and re-cutting is not performed. In addition, in the case of L1≥Lt1, it indicates that the die-cutting of the first pole piece has been completed (for example, the die-cutting of the last pole ear 910 of the first pole piece and the mark 911 on the pole ear 910 has been completed), so there is no need to perform reset and re-cutting, and the original die-cutting process can be continued, and the first pole piece can be marked as defective for subsequent removal.

[0084] In some embodiments, as shown in FIG3 , in the case where the pole piece material is a double-sided pole piece material, the pole piece die-cutting method may further include: in response to the first visual inspection unit 110 detecting the presence of a defect 990 on the pole piece material 900, determining by the defect detection unit the pole piece material region where the defect 990 is located in the pole piece material 900; and determining a preset length threshold value based on the pole piece material region where the defect 990 is located in the pole piece material 900. Here, the pole piece material 900 may include two pole piece material regions, namely the first pole piece material region 901a and the second pole piece material region 901b shown in FIG3 . The two pole piece material regions may be defined by a cutting line extending along a first direction in the pole piece material 900, or in other words, the two pole piece material regions may be arranged in a second direction perpendicular to the first direction. In this way, the two pole piece material regions may be used to form different pole pieces respectively.

[0085] In the case of double-sided pole piece materials, the corresponding preset length threshold can be determined based on the distribution of defects and whether the pole piece die-cutting device is capable of performing asynchronous die-cutting.

[0086] Specifically, in some embodiments, determining the preset length threshold based on the electrode material region where the defect 990 is located in the electrode material 900 may include: in the case where the defect 990 is distributed in two electrode material regions, using the first length threshold Lt1 as the preset length threshold, for example, based on the total length of each electrode piece, the distance in the first direction between the preset position on the first electrode piece and the starting position of the first electrode piece, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit. In some embodiments, the first length threshold Lt1 is equal to the total length L0 of each electrode piece (i.e., the EA length of the electrode piece) minus the distance Ls in the first direction between the preset position on the first electrode piece and the starting position of the first electrode piece minus the distance Lc1 in the first direction between the first defect detection position of the first visual inspection unit 110 and the die-cutting position of the die-cutting unit 120, i.e., Lt1=L0-Ls-Lc1. That is to say, when the defect 990 is distributed in two pole piece material areas, there is no need to consider whether the pole piece die-cutting device can perform asynchronous die-cutting, because the two pole piece material parts with defects cannot be used anymore. Therefore, this situation is similar to the case of the single-sided pole piece material described above, and the first length threshold can be similarly used as the preset length threshold, and the pole piece material length of Lt1-L1 can be saved when L1<Lt1.

[0087] Further, as shown in Figure 3, the die-cutting unit may include a first die-cutting unit 121 and a second die-cutting unit 122. When the first distance is less than a preset length threshold, the die-cutting of the first pole piece is terminated, and the die-cutting unit performs die-cutting of the second pole piece on the pole piece material. This may include: for each pole piece material area in the two pole piece material areas, the die-cutting of the first pole piece is terminated, and the first die-cutting unit 121 and the second die-cutting unit 122 respectively perform die-cutting on the corresponding second pole piece, that is, the first die-cutting unit 121 and the second die-cutting unit 122 can respectively die-cut the pole ear 910 of the corresponding pole piece in the adjacent side edge area of ​​the pole piece material.

[0088] In other embodiments, when die-cutting of two electrode sheet material regions of the electrode sheet material 900 can be performed asynchronously, determining the preset length threshold based on the electrode sheet material region in which the defect 990 is located in the electrode sheet material 900 may include: using a first length threshold Lt1 as the preset length threshold, for example, based on the total electrode length of each electrode sheet, the distance in the first direction between a preset position on the first electrode sheet and the starting position of the first electrode sheet, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit. In some embodiments, the first length threshold Lt1 is equal to the total electrode length L0 of each electrode sheet minus the distance in the first direction Ls between the preset position on the first electrode sheet and the starting position of the first electrode sheet minus the distance in the first direction Lc1 between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit, i.e., Lt1 = L0 - Ls - Lc1. That is, when asynchronous die-cutting is possible, the situation of the electrode sheet material region on one side with a defect is similar to the situation of the electrode sheet material on one side, and the first length threshold Lt1 can be used as the preset length threshold. Accordingly, in the case of L1<Lt1, the pole piece material length Lt1-L1 can be saved.

[0089] Furthermore, in the case where the die-cutting of two pole piece material areas of the pole piece material 900 can be performed asynchronously and the die-cutting unit includes a first die-cutting unit 121 and a second die-cutting unit 122, if the first distance is less than a preset length threshold, the die-cutting of the first pole piece is terminated, and the die-cutting unit performs die-cutting of the second pole piece on the pole piece material, which may include: terminating the die-cutting of the first pole piece on a pole piece material area where there is a defect in the two pole piece material areas, and performing die-cutting of the second pole piece on the pole piece material area by a die-cutting unit of the first die-cutting unit 121 and the second die-cutting unit 122 close to the pole piece material area; and continuing to perform die-cutting on the pole piece material area according to preset die-cutting parameters by a die-cutting unit of the first die-cutting unit 121 and the second die-cutting unit 122 close to the pole piece material area on the other pole piece material area where there is no defect in the two pole piece material areas, wherein the preset die-cutting parameters correspond to the die-cutting parameters when no defects are detected on the pole piece material. In other words, in the area of ​​the pole piece material on one side where there is a defect, the corresponding die-cutting unit can perform resetting and re-cutting, while in the area of ​​the pole piece material where there is no defect, another die-cutting unit can continue to perform die-cutting according to the original die-cutting procedure.

[0090] In some embodiments, when die-cutting of two electrode sheet material regions of the electrode sheet material 900 can only be performed simultaneously, determining the preset length threshold based on the electrode sheet material region where the defect is located in the electrode sheet material may include: when the defect is distributed in only one of the two electrode sheet material regions, using a second length threshold Lt2 as the preset length threshold, for example, based on the total length of each electrode sheet, the distance in the first direction between a preset position on the first electrode sheet and the starting position of the first electrode sheet, and the distance in the first direction between the first defect detection position of the first visual inspection unit and the die-cutting position of the die-cutting unit. In some embodiments, the second length threshold Lt2 is equal to half the total length L0 of each electrode sheet minus the distance in the first direction Ls between the preset position on the first electrode sheet and the starting position of the first electrode sheet minus the distance in the first direction Lc1 between the first defect detection position of the first visual inspection unit 110 and the die-cutting position of the die-cutting unit 120, that is, Lt2 = L0 / 2-Ls-Lc1. Here, since the two pole piece material areas can only be die-cut synchronously, the waste of the pole piece material area without defects during the reset and re-cutting must be considered to determine the preset length threshold. Here, the second length threshold Lt2 as the preset length threshold satisfies Lt2 = L0 / 2-Ls-Lc1, which is generally not equal to the first length threshold Lt1 as described above.

[0091] Accordingly, when the first distance is less than a preset length threshold, terminating the die-cutting of the first pole piece, and performing the die-cutting of the second pole piece on the pole piece material by the die-cutting unit may include: for each pole piece material area in the two pole piece material areas, synchronously terminating the die-cutting of the first pole piece, and synchronously performing the die-cutting of the corresponding second pole piece by the first die-cutting unit 121 and the second die-cutting unit 122 respectively.

[0092] In some embodiments, as shown in Figures 4 and 5, the defect detection unit may include a second visual inspection unit 150 located behind the die-cutting unit, so as to combine with the defect detection unit to pre-determine whether there are defects on the pole piece material 900 before the die-cutting unit 120 performs die-cutting of the pole piece, so as to perform resetting and re-cutting earlier and reduce waste of the pole piece material 900.

[0093] In some embodiments, as shown in FIG4 , when the pole piece material 900 is a single-sided pole piece material, the third length threshold Lt3 can be used as a preset length threshold. In particular, when the final position of the first pole piece being die-cut is not located between the second visual inspection unit 150 and the die-cutting unit 120 when the defect 990 is detected, that is, when the final position of the first pole piece (for example, the mark 911 on the left side of FIG4 ) has not yet reached the second defect detection position of the second visual inspection unit 150, it indicates that there is a defect 990 on the first pole piece. In this case, the third length threshold should be set so that the first distance L1 should be less than the third length threshold. At this time, resetting and re-cutting should be performed immediately to avoid waste of pole piece length caused by the defect 990. On the other hand, when the final position of the first pole piece being die-cut is located between the second visual inspection unit 150 and the die-cutting unit 120 when the defect 990 is detected, it indicates that the defect 990 detected at this time is not located on the first pole piece being die-cut. Then the third length threshold should be set so that the first distance L1 is greater than or equal to the third length threshold, so that the die-cutting of the intact first pole piece can be completed to avoid waste of pole piece length.

[0094] Similarly, as shown in FIG5 , when the pole piece material 900 is a double-sided pole piece material and the die-cutting of the two pole piece material areas of the pole piece material can be performed asynchronously, the third length threshold can be used as a preset length threshold. Wherein, when the final position of the first pole piece being die-cut is not located between the second visual inspection unit 150 and the die-cutting unit 120 when the defect 990 is detected, that is, when the final position of the first pole piece (for example, the mark 911 on the left side of FIG4 ) has not yet reached the second defect detection position of the second visual inspection unit 150, it indicates that there is a defect 990 on the first pole piece, then the third length threshold should be set so that the first distance L1 should be less than the third length threshold, and at this time, resetting and re-cutting should be performed immediately to avoid waste of pole piece length caused by the defect 990. On the other hand, when the final position of the first pole piece being die-cut is located between the second visual inspection unit 150 and the die-cutting unit 120 when the defect 990 is detected, it indicates that the defect 990 detected at this time is not located on the first pole piece being die-cut. In this case, the third length threshold should be set so that the first distance L1 is greater than or equal to the third length threshold, so that the die-cutting of the intact first pole piece can be completed to avoid wasting the length of the pole piece. For example, when the first distance is greater than or equal to the third length threshold, the die-cutting unit can continue to perform die-cutting on the pole piece material according to the preset die-cutting parameters until the die-cutting of the first pole piece is completed, and then the die-cutting unit performs die-cutting on the second pole piece on the pole piece material, wherein the preset die-cutting parameters correspond to the die-cutting parameters when no defects are detected on the pole piece material.

[0095] In some embodiments, as shown in Figures 4 and 5, the third length threshold Lt3 is equal to the total pole piece length L0 of each pole piece plus the distance Lc2 in the first direction between the second defect detection position of the second visual inspection unit 150 and the die-cutting position of the die-cutting unit 120 minus the distance Ls in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, that is, the third length threshold Lt3 satisfies Lt3 = L0-Ls+Lc2.

[0096] In some embodiments, when the electrode material is a double-sided electrode material and the die-cutting of the two electrode material regions of the electrode material can only be performed synchronously, the fourth length threshold can be used as a preset length threshold. The fourth length threshold can be determined based on the total length of each electrode, the distance in the first direction between the preset position on the first electrode and the starting position of the first electrode, and the distance in the first direction between the second defect detection position of the second visual inspection unit and the die-cutting position of the die-cutting unit. For example, as shown in FIG5 , the fourth length threshold Lt4 is equal to half of the total length L0 of each electrode plus the distance Lc2 in the first direction between the second defect detection position of the second visual inspection unit 150 and the die-cutting position of the die-cutting unit minus the distance Ls in the first direction between the preset position on the first electrode and the starting position of the first electrode, that is, Lt4 = L0 / 2-Ls+Lc2. Here, since the die-cutting of the double-sided electrode material can only be performed synchronously, the waste of performing reset and re-cutting on the electrode material region without defects must be considered to determine the corresponding preset length threshold, that is, the fourth length threshold Lt4.

[0097] Finally, 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 method for die-cutting a pole piece, characterized in that, The method for die-cutting a pole piece includes: Providing a pole piece material; During the process of die-cutting the pole piece material by a die-cutting unit to produce a pole piece with the length of a single-cell pole piece, defect detection of the pole piece material is performed by a defect detection unit, wherein the pole piece with the length of a single-cell pole piece is indicated by a mark die-cut on the pole piece; In response to detecting a defect on the pole piece material by the defect detection unit, depending on the position of the detected defect on the first pole piece being die-cut, terminating the die-cutting of the first pole piece and restarting the die-cutting of the second pole piece.

2. The method for die-cutting an electrode tab according to claim 1, wherein In response to detecting a defect on the pole piece material by the defect detection unit, depending on the position of the detected defect on the first pole piece being die-cut, terminating the die-cutting of the first pole piece and restarting the die-cutting of the second pole piece includes: In response to detecting a defect on the pole piece material by the defect detection unit, determining a first distance in a first direction between the defect and a preset position on the first pole piece, wherein the first direction is the moving direction of the pole piece material during the die-cutting process; Comparing the first distance with a preset length threshold; and In the case where the first distance is less than the preset length threshold, terminating the die-cutting of the first pole piece and having the die-cutting unit perform die-cutting of the second pole piece on the pole piece material.

3. The method for die-cutting the pole piece according to claim 2, wherein, The method for die-cutting a pole piece further includes: In the case where the first distance is greater than or equal to the preset length threshold, performing defective product identification on the first pole piece by an identification unit.

4. The method for die-cutting a pole piece according to claim 2, wherein, The method for die-cutting a pole piece further includes: In the case where the first distance is greater than or equal to the preset length threshold, having the die-cutting unit continue to perform die-cutting on the pole piece material according to preset die-cutting parameters, wherein the preset die-cutting parameters correspond to the die-cutting parameters in the case where no defect is detected on the pole piece material.

5. The method for die-cutting the pole piece according to claim 2, wherein, The defect detection unit performs defect detection on the pole piece material according to the photographing of the pole piece material by a visual detection unit. The visual detection unit includes a first visual detection unit located in front of the die-cutting unit in the first direction. In the case where the pole piece material is a single-sided pole piece material with pole tabs die-cut on only one side perpendicular to the moving direction, using a first length threshold as the preset length threshold, wherein the first length threshold is determined based on the total length of each pole piece, the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

6. The method for die-cutting an electrode sheet according to claim 5, characterized in that The first length threshold is equal to the total length of each pole piece minus the distance in the first direction between the preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

7. The method for die-cutting a pole piece according to claim 2, characterized in that, The defect detection unit performs defect detection on the pole piece material according to the photographing of the pole piece material by a visual detection unit. The visual detection unit includes a first visual detection unit located in front of the die-cutting unit in the first direction. In the case where the pole piece material is a double-sided pole piece material with pole tabs die-cut on both sides perpendicular to the moving direction, the method for die-cutting a pole piece further includes: In response to a defect being detected on the pole piece material by the first visual detection unit, the defect detection unit determines the pole piece material region in the pole piece material where the defect is located. The pole piece material includes two pole piece material regions, and the two pole piece material regions are defined by a tangent line extending in a first direction in the pole piece material. The two pole piece material regions are respectively used to form different pole pieces; and Based on the pole piece material region in the pole piece material where the defect is located, the preset length threshold is determined.

8. The method for die-cutting a pole piece according to claim 7, wherein, Determining the preset length threshold based on the pole piece material region in the pole piece material where the defect is located includes: When the defect is distributed in the two pole piece material regions, the first length threshold is used as the preset length threshold. The first length threshold is determined based on the total length of each pole piece, the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

9. The method for die-cutting a pole piece according to claim 8, wherein, The first length threshold is equal to the total length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

10. The method for die-cutting the pole piece according to claim 8 or 9, characterized in that, The die-cutting unit includes a first die-cutting unit and a second die-cutting unit. When the first distance is less than the preset length threshold, terminating the die-cutting of the first pole piece and the die-cutting unit performing die-cutting of the second pole piece on the pole piece material includes: For each of the two pole piece material regions, terminating the die-cutting of the first pole piece, and the first die-cutting unit and the second die-cutting unit respectively performing die-cutting of the corresponding second pole piece.

11. The method for die-cutting a pole piece according to claim 7, wherein When the die-cutting of the two pole piece material regions of the pole piece material can be performed asynchronously, determining the preset length threshold based on the pole piece material region in the pole piece material where the defect is located includes: Using the first length threshold as the preset length threshold. The first length threshold is determined based on the total length of each pole piece, the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece, and the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

12. The method for die-cutting a pole piece according to claim 11, wherein The first length threshold is equal to the total length of each pole piece minus the distance in the first direction between a preset position on the first pole piece and the starting position of the first pole piece minus the distance in the first direction between the first defect detection position of the first visual detection unit and the die-cutting position of the die-cutting unit.

13. The method for die-cutting the pole piece according to claim 11 or 12, characterized in that, The die-cutting unit includes a first die-cutting unit and a second die-cutting unit. When the first distance is less than the preset length threshold, terminating the die-cutting of the first pole piece and the die-cutting unit performing die-cutting of the second pole piece on the pole piece material includes: On one of the two electrode sheet material regions where the defect exists in the electrode sheet material regions, the die-cutting of the first electrode sheet is terminated, and the die-cutting of the second electrode sheet is performed on this electrode sheet material region by one of the first die-cutting unit and the second die-cutting unit that is closer to this electrode sheet material region; and On the other electrode sheet material region where the defect does not exist in the two electrode sheet material regions, by the first die-cutting unit and one of the second die-cutting units that is closer to this electrode sheet material region, continue to perform die-cutting on this electrode sheet material region according to the preset die-cutting parameters, where the preset die-cutting parameters correspond to the die-cutting parameters in the case where no defect is detected on the electrode sheet material.

14. The method for die-cutting the pole piece according to claim 7, wherein In the case where the die-cutting of the two electrode sheet material regions of the electrode sheet material can only be performed synchronously, determining the preset length threshold according to the electrode sheet material region where the defect is located in the electrode sheet material includes: In the case where the defect is distributed in only one of the two electrode sheet material regions, taking the second length threshold as the preset length threshold, where the second length threshold is determined based on the total length of each electrode sheet, the distance in the first direction between the preset position on the first electrode sheet and the starting position of the first electrode sheet, and the distance in the first direction between the first defect detection position of the first vision detection unit and the die-cutting position of the die-cutting unit.

15. The method for die-cutting the pole piece according to claim 14, wherein The second length threshold is equal to half of the total length of each electrode sheet minus the distance in the first direction between the preset position on the first electrode sheet and the starting position of the first electrode sheet minus the distance in the first direction between the first defect detection position of the first vision detection unit and the die-cutting position of the die-cutting unit.

16. The pole piece die-cutting method according to claim 14 or 15, characterized in that The die-cutting unit includes a first die-cutting unit and a second die-cutting unit. In the case where the first distance is less than the preset length threshold, terminating the die-cutting of the first electrode sheet, and the die-cutting of the second electrode sheet performed by the die-cutting unit on the electrode sheet material includes: For each of the two electrode sheet material regions, terminate the die-cutting of the first electrode sheet synchronously, and respectively perform the die-cutting of the corresponding second electrode sheet synchronously by the first die-cutting unit and the second die-cutting unit.

17. The method for die-cutting the pole piece according to claim 2, characterized in that, The defect detection unit performs defect detection on the electrode sheet material according to the photographing of the electrode sheet material by the vision detection unit. The vision detection unit includes a second vision detection unit located behind the die-cutting unit in the first direction. In the case where the electrode sheet material is a single-sided electrode sheet material with tabs die-cut on only one side perpendicular to the moving direction, taking the third length threshold as the preset length threshold, where in the case where the end position of the first electrode sheet being die-cut when the defect is detected is not located between the second vision detection unit and the die-cutting unit, the first distance is less than the third length threshold, and in the case where the end position of the first electrode sheet being die-cut when the defect is detected is located between the second vision detection unit and the die-cutting unit, the first distance is greater than or equal to the third length threshold.

18. The method for die-cutting the pole piece according to claim 2, wherein The defect detection unit performs defect detection on the electrode sheet material based on the photographing of the electrode sheet material by the vision detection unit. The vision detection unit includes a second vision detection unit located behind the die-cutting unit in the first direction. When the electrode sheet material is a double-sided electrode sheet material with tabs die-cut on both sides perpendicular to the moving direction, and the die-cutting of the two electrode sheet material regions of the electrode sheet material can be performed asynchronously, the third length threshold is used as the preset length threshold. Here, the electrode sheet material includes two electrode sheet material regions, the two electrode sheet material regions are defined by a dividing tangent line extending in the first direction in the electrode sheet material, and the two electrode sheet material regions are respectively used to form different electrode sheets. When the end position of the first electrode sheet being die-cut at the time of detecting the defect is not located between the second vision detection unit and the die-cutting unit, the first distance is less than the third length threshold, and when the end position of the first electrode sheet being die-cut at the time of detecting the defect is located between the second vision detection unit and the die-cutting unit, the first distance is greater than or equal to the third length threshold.

19. The pole piece die-cutting method according to claim 17 or 18, characterized in that, The third length threshold is equal to the total length of each electrode sheet plus the distance in the first direction between the second defect detection position of the second vision detection unit and the die-cutting position of the die-cutting unit minus the distance in the first direction between the preset position on the first electrode sheet and the starting position of the first electrode sheet.

20. The pole piece die-cutting method according to claim 17 or 18, characterized in that, The electrode sheet die-cutting method further includes: When the first distance is greater than or equal to the third length threshold, the die-cutting unit continues to perform die-cutting on the electrode sheet material according to the preset die-cutting parameters until the die-cutting of the first electrode sheet is completed, and then the die-cutting unit performs die-cutting on the second electrode sheet on the electrode sheet material, where the preset die-cutting parameters correspond to the die-cutting parameters in the case where no defect is detected on the electrode sheet material.

21. The method for die-cutting a pole piece according to claim 2, characterized in that, The defect detection unit performs defect detection on the electrode sheet material based on the photographing of the electrode sheet material by the vision detection unit. The vision detection unit includes a second vision detection unit located behind the die-cutting unit in the first direction. When the electrode sheet material is a double-sided electrode sheet material with tabs die-cut on both sides perpendicular to the moving direction, and the die-cutting of the two electrode sheet material regions of the electrode sheet material can only be performed synchronously, the fourth length threshold is used as the preset length threshold. Here, the electrode sheet material includes two electrode sheet material regions, the two electrode sheet material regions are defined by a dividing tangent line extending in the first direction in the electrode sheet material, and the two electrode sheet material regions are respectively used to form different electrode sheets. The fourth length threshold is determined based on the total length of each electrode sheet, the distance in the first direction between the preset position on the first electrode sheet and the starting position of the first electrode sheet, and the distance in the first direction between the second defect detection position of the second vision detection unit and the die-cutting position of the die-cutting unit.

22. The method for die-cutting the pole piece according to claim 21, wherein, The fourth length threshold is equal to half of the total length of each electrode sheet plus the distance in the first direction between the second defect detection position of the second vision detection unit and the die-cutting position of the die-cutting unit minus the distance in the first direction between the preset position on the first electrode sheet and the starting position of the first electrode sheet.

23. A pole piece die-cutting device, characterized in that, The pole piece die-cutting device includes: a vision detection unit configured to photograph the pole piece material; a defect detection unit communicatively connected to the vision detection unit and configured to determine whether there is a defect on the pole piece material based on the image photographed by the vision detection unit; a die-cutting unit communicatively connected to the defect detection unit and configured to perform die-cutting of the pole piece; and a control unit communicatively connected to the defect detection unit and the die-cutting unit and configured to, in response to detecting a defect on the pole piece material, depending on the position of the detected defect on the first pole piece being die-cut, terminate the die-cutting of the first pole piece and restart die-cutting the second pole piece.

24. The pole piece die-cutting device according to claim 23, wherein, The pole piece die-cutting device further includes: an identification unit communicatively connected to the defect detection unit and the control unit, the identification unit being located in front of the vision detection unit in a first direction and configured to identify defective pole pieces.

25. The pole piece die-cutting device according to claim 23, wherein, The vision detection unit includes at least one of the following: a first vision detection unit located in front of the die-cutting unit in a first direction; and a second vision detection unit located behind the die-cutting unit in a first direction.

26. The pole piece die-cutting device according to claim 23, wherein, The pole piece die-cutting device further includes: a slitting unit located in front of the vision detection unit in a first direction and configured to slit two pole piece material regions included in the pole piece material along a slitting line extending in the first direction in the pole piece material, the two pole piece material regions being respectively used to form different pole pieces.

27. The pole piece die-cutting device according to claim 26, wherein The die-cutting unit includes: a first die-cutting unit; and a second die-cutting unit, wherein the first die-cutting unit and the second die-cutting unit are respectively located at two ends in a second direction perpendicular to the first direction.

Images