Method, device and equipment for measuring size of gap between positive and negative pole pieces of battery cell and medium

Abstract

The invention discloses a method, a device and equipment for measuring the size of a gap between positive and negative pole pieces of a battery cell and a medium. The method for acquiring the size of the gap between the positive and negative pole pieces of the battery cell comprises the following steps: acquiring a computed tomography image of the battery cell; a plane shown by the image is perpendicular to the length direction of the battery cell; obtaining the number of gap pixels between the contours of two adjacent positive plates in the image; and obtaining the size of the gap between the positive and negative pole pieces of the battery cell according to the number of the gap pixels. According to the measurement method, the number of the gap pixels between the outlines of the two adjacent positive plates in the image is obtained, and the size of the gap between the positive and negative plates of the battery cell is obtained according to the number of the gap pixels, so that the size of the gap between the positive and negative plates of the battery cell is automatically obtained, and the consistency and the accuracy of measurement results are greatly improved; the missed killing rate is reduced, and the working efficiency is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a method, device, equipment and medium for measuring the gap size between positive and negative electrode sheets of a battery cell. Background Art

[0002] Winding or lamination is one of the key process steps in battery manufacturing. Taking the winding battery process as an example, the cathode, anode and separator are wound together in a spiral form through winding equipment to form a bare battery structure with cathode-separator-anode alternately arranged, so as to achieve the maximum facing space between the positive and negative electrodes in the smallest space. As the battery undergoes processes such as charging and discharging, the internal electrode sheets will expand. If the expansion cannot be extended, it will cause distortion. According to the deformation mechanism of the battery, the gap between the positive and negative electrode sheets (referred to as GAP) can be controlled to allow enough space for expansion, thereby reducing the deformation of the battery. The winding GAP parameters are directly related to the performance and safety performance of the battery during charging and discharging. How to accurately measure GAP is of great significance to the optimization of battery manufacturing processes and battery safety.

[0003] In the related art, the technical means to measure the gap between the positive and negative pole pieces of a battery is to manually use a measuring tool to directly mark and measure the GAP on the image. The consistency and accuracy of the measurement results are not high, and the missed rate is high.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] In view of the problems in the above-mentioned related technologies of the measurement consistency and accuracy of the gap between the positive and negative pole pieces of the battery, and the high missed kill rate, the present application provides a method, device, equipment and medium for measuring the gap size between the positive and negative pole pieces of a battery cell.

[0006] According to a first aspect of an embodiment of the present application, a method for obtaining the gap size between positive and negative electrode sheets of a battery cell is provided, comprising:

[0007] Acquire a computer tomography image of the battery cell; the plane shown in the image is perpendicular to the length direction of the battery cell;

[0008] Obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the image;

[0009] According to the number of gap pixels, the size of the gap between the positive and negative electrode sheets of the battery cell is obtained.

[0010] The first aspect of an embodiment of the present application provides a method for acquiring the size of the gap between the positive and negative electrode sheets of a battery cell, which acquires the number of gap pixels between the outlines of two adjacent positive electrode sheets in an image, and acquires the size of the gap between the positive and negative electrode sheets of the battery cell based on the number of gap pixels, thereby realizing automatic acquisition of the size of the gap between the positive and negative electrode sheets of the battery cell, greatly improving the consistency and accuracy of the measurement results, reducing the missed kill rate, and greatly improving work efficiency.

[0011] In some embodiments of the present application, obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the image includes:

[0012] Obtaining the contour of each pole piece in the image;

[0013] Based on the contours of the pole pieces, the number of gap pixels between the contours of two adjacent positive pole pieces is obtained.

[0014] Compared with the manual annotation processing method in the related art, in this embodiment, the contour of each pole piece in the image is obtained, and then the number of gap pixels between the contours of two adjacent positive pole pieces is obtained based on the contour of each pole piece. Each pixel in the image can be accurately analyzed. Through pixel-level processing, it can be accurate to a smaller size level. The contour extraction accuracy and the calculation accuracy of the gap pixel number are much higher than the accuracy of manual annotation measurement, which greatly improves the consistency and accuracy of the measurement results.

[0015] In some embodiments of the present application, the step of obtaining the number of gap pixels between the contours of two adjacent positive electrode pieces based on the contours of the electrode pieces includes:

[0016] Draw a first straight line on the image, the first straight line passes through the starting point of the convex surface contour of the first folded positive electrode piece of the battery cell, and the first straight line intersects with the contour of each electrode piece;

[0017] According to the intersection of the first straight line and the contours of the two adjacent positive electrode sheets, the number of gap pixels between the contours of the two adjacent positive electrode sheets is obtained.

[0018] By drawing a straight line at the starting point of the convex contour of the first fold of the positive electrode of the battery cell, the intersection of the straight line and the contour of the electrode is clear and reproducible. In this way, the measurement results are more accurate because each intersection is determined by the interaction between the straight line and the contour, which does not rely on human subjective judgment, thereby improving the accuracy of the measurement results. By automatically determining the intersection and obtaining the number of gap pixels, there is no need to manually mark and manually measure the pixels of each intersection. In this way, the need for manual intervention is greatly reduced, the possibility of human error is reduced, and the processing speed is improved.

[0019] In some embodiments of the present application, obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels includes:

[0020] According to the corresponding relationship between the number of pixels and the actual size, the number of gap pixels is converted into the corresponding actual size;

[0021] Based on the corresponding actual size, the size of the gap between the positive and negative electrode sheets of the battery cell is obtained.

[0022] By pre-establishing the correspondence between pixels and actual size, the number of pixels in the image can be accurately converted into the actual physical size, thus eliminating the influence of factors such as image resolution and shooting angle, ensuring high-precision measurement results. After the details captured in the image are converted to actual size, the high-precision image resolution is retained, which improves the detail and accuracy of the gap size measurement results.

[0023] In some embodiments of the present application, there are two separators and one negative electrode sheet between the two adjacent positive electrode sheets, the two separators are located between the two adjacent positive electrode sheets, and the negative electrode sheet is located between the two separators;

[0024] Before obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size, the method further includes:

[0025] Scan the label on the battery cell to obtain the formula information of the battery cell;

[0026] Acquire the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet from the formula information of the battery cell;

[0027] The obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size includes:

[0028] The size of the gap between the positive and negative electrode sheets of the battery cell is obtained according to the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation membrane, the expansion coefficient of the positive electrode sheet and the expansion coefficient of the negative electrode sheet.

[0029] By obtaining various parameters in the battery cell formula, such as the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, and the expansion coefficient, the actual gap size of the positive and negative electrode sheets inside the battery cell can be calculated more accurately. This calculation method based on formula parameters can greatly reduce the errors in manual measurement, and take into account dynamic change factors such as material expansion, thereby providing more accurate dimensional data. During the use of the battery cell, the expansion characteristics of the positive and negative electrode sheets and the separator will affect the internal gap size of the battery cell. By introducing the expansion coefficient of the positive and negative electrode sheets in the calculation, the expansion effect of the battery cell under different use conditions can be predicted and compensated, thereby accurately evaluating the gap changes of the battery cell in the actual working environment and reducing performance problems caused by excessive expansion.

[0030] In some embodiments of the present application, the obtaining of the size of the gap between the positive and negative electrode sheets of the battery cell according to the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet includes:

[0031] Subtracting the first value, the second value and the third value from the corresponding actual size to obtain a fourth value; the first value is the product of the thickness of the positive electrode sheet and the expansion coefficient of the positive electrode sheet, the second value is the product of the thickness of the negative electrode sheet and the expansion coefficient of the negative electrode sheet, and the third value is twice the thickness of the isolation film;

[0032] The fourth value is divided by two to obtain the size of the gap between the positive and negative electrode sheets of the battery cell.

[0033] In this way, by considering the various components of the battery cell, such as the positive electrode, negative electrode and separator and their expansion coefficients, the size of the gap between the positive and negative electrode sheets can be calculated more accurately. This precise calculation takes into account the impact of material expansion in actual use, reduces the error that may be caused by simple static size calculations, and thus obtains a more accurate size of the gap between the positive and negative electrode sheets of the battery cell. Through this formulaic calculation method, the size calculation of the gap between the positive and negative electrode sheets of the battery cell during production and testing can be completed automatically, reducing manual intervention and reducing human errors. This automated calculation not only improves work efficiency, but also makes the production process of each battery cell more standardized and standardized, further optimizing the production process.

[0034] In some embodiments of the present application, the step of obtaining the contour of each pole piece in the image includes:

[0035] Acquire a contour area of ​​each positive electrode piece according to the grayscale of the positive electrode piece and the negative electrode piece in the image;

[0036] The region of interest is extracted from the contour area of ​​each positive electrode piece to obtain the contour of each positive electrode piece.

[0037] By distinguishing the contour area based on the grayscale difference between the positive and negative pole pieces, the pole piece boundaries can be identified more accurately, background interference and errors can be reduced, and the extraction accuracy can be improved. Extracting the region of interest in the contour area of ​​the positive pole piece helps to focus on key areas and reduce the interference of irrelevant background information, thereby improving processing efficiency and accuracy and obtaining an accurate contour of the positive pole piece.

[0038] In some embodiments of the present application, before converting the number of gap pixels into the corresponding actual size according to the correspondence between the number of pixels and the actual size, the method further includes:

[0039] The pixel ratio mark on the image is identified to obtain the corresponding relationship between the number of pixels and the actual size.

[0040] By identifying the pixel ratio mark on the image and obtaining the corresponding relationship between the number of pixels and the actual size, the function of converting the number of gap pixels to the actual size is realized. By accurately identifying the pixel ratio mark, it can be ensured that the conversion relationship between the number of pixels and the actual size is correct and accurate. Regardless of how the resolution of the image changes, this method can accurately convert the pixel values ​​in the image to the actual physical size, thereby reducing the errors that may be introduced by different devices or shooting conditions. By identifying the pixel ratio mark, the calculation ratio can be adjusted before each image processing to adapt to different image resolutions. This makes the method highly versatile and can be widely used in images of different sources and resolutions.

[0041] In some embodiments of the present application, the method further includes:

[0042] According to the preset size threshold of the gap between the positive and negative electrode sheets, it is judged whether the size of the gap between the positive and negative electrode sheets of the battery cell meets the gap control requirements, and a judgment result is obtained.

[0043] By setting a clear size threshold, it is possible to accurately determine whether the gap between the positive and negative plates of the battery cell meets the design standards. This threshold-based automated detection can reduce human errors and improve the accuracy of the gap size between the positive and negative plates of the battery cell, thereby improving the quality stability of the battery cell and the consistency of the battery cell performance.

[0044] According to a second aspect of an embodiment of the present application, a device for obtaining the gap size between positive and negative electrode sheets of a battery cell is provided, comprising:

[0045] An image acquisition module, used to acquire a computer tomography image of the battery cell; the plane shown in the image is perpendicular to the length direction of the battery cell;

[0046] A gap pixel number acquisition module is used to acquire the number of gap pixels between the outlines of two adjacent positive electrode sheets in the image;

[0047] The gap size acquisition module is used to acquire the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels.

[0048] The second aspect of the embodiment of the present application provides a device for acquiring the gap size between the positive and negative electrode sheets of a battery cell, which can acquire the number of gap pixels between the outlines of two adjacent positive electrode sheets in an image, and acquire the size of the gap between the positive and negative electrode sheets of the battery cell based on the number of gap pixels, thereby realizing automatic acquisition of the gap size between the positive and negative electrode sheets of the battery cell, greatly improving the consistency and accuracy of the measurement results, reducing the missed kill rate, and greatly improving work efficiency.

[0049] According to a third aspect of an embodiment of the present application, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for obtaining the gap size between the positive and negative electrode sheets of a battery cell as described in any embodiment of the present application.

[0050] The electronic device provided in the third aspect of the embodiment of the present application is capable of obtaining the number of gap pixels between the outlines of two adjacent positive plates in an image, and obtaining the size of the gap between the positive and negative plates of the battery cell based on the number of gap pixels, thereby realizing automatic acquisition of the size of the gap between the positive and negative plates of the battery cell, greatly improving the consistency and accuracy of the measurement results, reducing the missed kill rate, and greatly improving work efficiency.

[0051] According to a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and the computer program is executed by a processor to implement the method for obtaining the gap size between the positive and negative electrode sheets of a battery cell as described in any embodiment of the present application.

[0052] The computer-readable storage medium provided in the fourth aspect of the embodiment of the present application can obtain the number of gap pixels between the outlines of two adjacent positive plates in the image, and obtain the size of the gap between the positive and negative plates of the battery cell based on the number of gap pixels, thereby realizing the automatic acquisition of the gap size between the positive and negative plates of the battery cell, greatly improving the consistency and accuracy of the measurement results, reducing the missed kill rate, and greatly improving work efficiency.

[0053] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment 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 embodiment 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

[0054] By reading the detailed description of the following embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used to illustrate the embodiments of the present application and are not to be considered as limitations of the present application. In addition, the same reference numerals are used to represent the same components throughout the drawings.

[0055] Figure 1 The present invention is a flow chart of a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell according to one or more embodiments.

[0056] Figure 2 is a schematic diagram of the structure of a battery cell according to one or more embodiments.

[0057] Figure 3 is a schematic cross-sectional view of a battery cell according to one or more embodiments.

[0058] Figure 4 A flow chart of obtaining the number of gap pixels between contours of two adjacent positive electrode sheets in a CT image according to one or more embodiments.

[0059] Figure 5 CT images of a corner of a battery cell according to one or more embodiments.

[0060] Figure 6 FIG. 4 is a partial diagram of a CT image of a corner of a battery cell according to one or more embodiments.

[0061] Figure 7 CT images of a corner of a battery cell according to one or more embodiments.

[0062] Figure 8 Schematic diagram of two adjacent positive electrode plates at the corner of a battery cell according to one or more embodiments.

[0063] Fig. 9 is a schematic diagram of a corner portion of a battery cell according to one or more embodiments.

[0064] Fig.10 The present invention is a flow chart of a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell according to one or more embodiments.

[0065] Fig.11 The present invention is a flow chart of a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell according to one or more embodiments.

[0066] Fig.12 The present invention is a flowchart of the steps of obtaining a cell barcode and associating a recipe according to one or more embodiments.

[0067] Fig.13 FIG. 4 is a schematic diagram of the relationship among a GAP measurement system, a CT test system, and a production system according to one or more embodiments.

[0068] Fig.14 The present invention is a structural block diagram of a device for obtaining the gap size between the positive and negative electrode sheets of a battery cell according to one or more embodiments.

[0069] Fig.15 is a structural block diagram of an electronic device according to one or more embodiments.

[0070] Fig.16 is a schematic diagram of a computer-readable storage medium according to one or more embodiments. DETAILED DESCRIPTION

[0071] The following embodiments of the technical solution of the present application will be described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0072] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0073] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), unless otherwise clearly and specifically defined.

[0074] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0075] Cell production is an important process step in the battery production process, especially in the manufacture of lithium batteries and other types of batteries. The cell is the core part of the battery. The cell includes components such as positive electrode sheets, negative electrode sheets, separators, and electrolytes, which are used to store and release electrical energy. The quality of the cell determines the performance, life, safety, and reliability of the entire battery.

[0076] GAP refers to the gap length between the positive and negative pole pieces of the battery cell, that is, the distance between the positive and negative pole pieces of the battery cell, which is an important process parameter in the battery manufacturing process. After the battery undergoes processes such as charging and discharging, the internal pole pieces will expand. If the expansion cannot be extended, it will cause distortion and deformation. According to the battery deformation mechanism, the gap between the positive and negative pole pieces can be controlled to allow enough space for expansion, thereby reducing the deformation of the battery. The winding GAP parameter is directly related to the performance and safety performance of the battery during charging and discharging.

[0077] In the related art, to measure the gap between the positive and negative pole pieces of a battery, the battery GAP image is first obtained, and then the GAP on the image is manually measured using a measurement tool according to a preset measurement logic. The position of the gap measurement between the positive and negative pole pieces needs to be marked along the horizontal, positive 30-45° or negative 30-45° directions for every 5 layers of positive pole pieces, and the distance from the convex surface to the convex surface of the positive pole piece is measured. The marked data is manually entered into the offline collection form, and then the GAP is converted through the thickness parameters of the positive pole piece, the negative pole piece, the isolation film, etc.

[0078] In the related art, in order to ensure the efficiency of manual measurement, GAP measurements are not performed at more locations of the battery corners. Only the average measurement of every five layers is used in the horizontal direction and the positive 30°-45° or negative 30°-45° directions. This measurement method is similar to sampling and marking, and has a high risk of missing. In addition, the manual measurement and marking of the gap between the positive and negative pole pieces is highly subjective, and there is no marking standard for the starting and ending points of the measurement, so the consistency and accuracy are poor.

[0079] In response to the problems existing in the related art, an embodiment of the present application provides a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell, obtaining a computer tomography image of the battery cell, wherein the plane shown in the image is perpendicular to the length direction of the battery cell, and then obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the image, and obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the number of gap pixels. In this way, the automatic acquisition of the gap size between the positive and negative electrode sheets of the battery cell is achieved, which greatly improves the consistency and accuracy of the measurement results, reduces the missed kill rate, greatly improves the work efficiency, and reduces the manual workload.

[0080] The method for obtaining the gap size between the positive and negative electrode sheets of a battery cell according to an embodiment of the present application can be applied to application scenarios including battery cell manufacturing process steps, such as battery manufacturing and other scenarios.

[0081] refer to Figure 1 As shown, an embodiment of the present application provides a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell, which may include steps S30 to S50:

[0082] S30, obtaining a computerized tomography (CT) image of the battery cell; the plane shown in the CT image is perpendicular to the length direction of the battery cell.

[0083] Computed Tomography (CT) is an imaging technology that uses X-ray beams to scan objects layer by layer and uses computer processing to produce detailed images of the internal structure of the object.

[0084] The shape of the battery cell includes but is not limited to a cylinder, a cuboid, and the like. The battery cell includes multiple layers of positive electrode sheets, multiple layers of negative electrode sheets, multiple layers of isolation films, and an electrolyte. A layer of negative electrode sheets is disposed between every two layers of positive electrode sheets. The multiple layers of electrode sheets are wound from the inside to the outside. Due to the winding arrangement, there is a curved surface on each electrode sheet, and the curved surface portion can be called the corner of the battery cell.

[0085] Taking a cylindrical battery cell as an example, multiple layers of pole pieces are wound outward from the central axis of the cylinder, and a negative pole piece is arranged between each two adjacent positive pole pieces. The central axis direction of the cylinder is the length direction of the battery cell. The plane shown in the CT image is perpendicular to the length direction of the battery cell, that is, the CT image is a radial cross-sectional image of the battery cell. For a cylindrical battery cell, each pole piece is a curved surface as a whole.

[0086] Another commonly used battery cell has a "flat" rectangular shape as the overall shape, that is, the thickness of the rectangular cell is relatively small, for example, the dimensions are 102.7mm in length, 58.2mm in width, and 9.80mm in thickness. In this way, the CT image of the rectangular cell is a cross-section of 58.2mm×9.80mm in size. The shapes of the two ends of the cross-section in the width direction are arc-shaped, and the arc-shaped parts can be called the corners of the battery cell. The rectangular cell has a curved surface and a straight surface on each pole piece, and the curved surface part can be called the corner of the battery cell.

[0087] refer to Figure 2 As shown, the overall shape of the battery cell is a "flat" rectangular parallelepiped, the length direction of the battery cell is parallel to the z-axis, the width direction is parallel to the y-axis, and the thickness direction is parallel to the x-axis. The battery cell includes a tab 1, a multi-layer separator 2, a multi-layer positive electrode sheet 3, and a multi-layer negative electrode sheet 4. The battery cell has corners 5 and 6 formed on both sides in the width direction. Figure 3 Shown Figure 2 In the cross-sectional view of the middle cell perpendicular to the length direction of the cell (i.e., the direction parallel to the z-axis direction), the cell has corners 5 and 6 formed on both sides in the width direction. Figure 3 In the figure, the cross-sectional shapes of corners 5 and 6 are both semicircular.

[0088] For example, a computed tomography (CT) image of a corner of the battery cell may be directly acquired, and then the size of the gap between the positive and negative electrode sheets of the battery cell may be acquired based on the CT image of the corner.

[0089] S40, obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the CT image.

[0090] refer to Figure 4 As shown, in some embodiments, obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the CT image may include:

[0091] S401, obtaining the contour of each pole piece in the CT image.

[0092] In some embodiments, obtaining the contour of each pole piece in the CT image may include: obtaining the contour area of ​​each positive pole piece based on the grayscale of the positive pole piece and the negative pole piece in the CT image; and performing region of interest extraction on the contour area of ​​each positive pole piece to obtain the contour of each positive pole piece.

[0093] Specifically, the contour area of ​​each positive electrode piece is obtained according to the grayscale difference between the positive electrode piece and the negative electrode piece in the CT image through the image processing algorithm. By distinguishing the contour area according to the grayscale difference between the positive and negative electrode pieces, the boundary of the electrode piece can be identified more accurately, the background interference and error can be reduced, and the extraction accuracy can be improved. The region of interest extraction of the contour area of ​​the positive electrode piece helps to focus on the key areas and reduce the interference of irrelevant background information, thereby improving the processing efficiency and accuracy and obtaining the accurate contour of the positive electrode piece.

[0094] The curved surface of the pole piece includes a concave portion and a convex portion, the concave portion is divided into a side surface of the pole piece close to the central axis of the battery cell, and the convex portion is divided into a side surface of the pole piece away from the central axis of the battery cell. The contour of the pole piece includes a concave contour portion and a convex contour portion.

[0095] Exemplarily, the edge contours of the positive and negative electrode sheets can be extracted through an image processing algorithm according to a pre-defined measurement logic. For example, the measurement logic can select the spacing between adjacent positive (or negative) electrode sheets, GAP measurement, every 1 / 3 / 5 layers of positive (or negative) electrode sheets, etc. The measurement position can be measured every 5 / 10 / 15 / 30° within the range of ±60° at the corner. It can be selected according to the needs of the actual application to meet different measurement scenarios and data analysis requirements.

[0096] refer to Figure 5 As shown, the outline 7 of the positive electrode sheet and the outline 8 of the negative electrode sheet are shown. Figure 6 As shown, the outline 7 of the positive electrode sheet and the outline 8 of the negative electrode sheet are shown.

[0097] S402: Based on the contour of each electrode piece, obtain the number of gap pixels between the contours of two adjacent positive electrode pieces.

[0098] Compared with the manual annotation processing method in the related art, in this embodiment, the contour of each pole piece in the image is obtained, and then the number of gap pixels between the contours of two adjacent positive pole pieces is obtained based on the contour of each pole piece. Each pixel in the image can be accurately analyzed. Through pixel-level processing, it can be accurate to a smaller size level. The contour extraction accuracy and the calculation accuracy of the gap pixel number are much higher than the accuracy of manual annotation measurement, which greatly improves the consistency and accuracy of the measurement results.

[0099] In some embodiments, based on the contours of each electrode piece, obtaining the number of gap pixels between the contours of two adjacent positive electrode pieces may include:

[0100] Draw a first straight line on the CT image, the first straight line passes through the starting point of the convex surface contour of the first folded positive electrode piece of the battery cell, and the first straight line intersects with the contours of each electrode piece;

[0101] According to the intersection point between the first straight line and the contours of the two adjacent positive electrode sheets, the number of gap pixels between the contours of the two adjacent positive electrode sheets is obtained.

[0102] The first folded positive electrode sheet of the battery cell is the innermost positive electrode sheet of all the positive electrode sheets of the battery cell. The first straight line intersects both the concave contour part and the convex contour part of each electrode sheet.

[0103] refer to Figure 7 As shown, in one example, Figure 7 The starting point 9 of the convex contour of the first folded positive electrode sheet is shown in the figure. The 0° straight line is parallel to the width direction of the battery cell and passes through the starting point 9 of the convex contour of the first folded positive electrode sheet. Other straight lines passing through the starting point 9 of the convex contour of the first folded positive electrode sheet are also shown, including ±10°, ±15°, ±20°, ..., ±60° straight lines, which can reduce the risk of missing.

[0104] refer to Figure 8 As shown, Figure 8 The figure shows the Nth layer of positive electrode sheet 10 and the N+1th layer of positive electrode sheet 11, as well as a plurality of straight lines passing through the starting point 9 of the convex surface contour of the first folded positive electrode sheet.

[0105] By drawing a straight line at the starting point of the convex contour of the first fold of the positive electrode of the battery cell, the intersection of the straight line and the contour of the electrode is clear and reproducible. In this way, the measurement results are more accurate because each intersection is determined by the interaction between the straight line and the contour, which does not rely on human subjective judgment, thereby improving the accuracy of the measurement results. By automatically determining the intersection and obtaining the number of gap pixels, there is no need to manually mark and manually measure the pixels of each intersection. In this way, the need for manual intervention is greatly reduced, the possibility of human error is reduced, and the processing speed is improved.

[0106] S50 , obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels.

[0107] In some embodiments, obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels may include:

[0108] S501, converting the number of gap pixels into the corresponding actual size according to the corresponding relationship between the number of pixels and the actual size;

[0109] S502: Based on the corresponding actual size, obtain the size of the gap between the positive and negative electrode sheets of the battery cell.

[0110] refer to Fig. 9 As shown, Fig. 9 The Nth layer of positive electrode sheet 10 and the N+1th layer of positive electrode sheet 11 are shown in the figure, and there are two layers of isolation membrane 13 between the Nth layer of positive electrode sheet 10 and the N+1th layer of positive electrode sheet 11, and there is a negative electrode sheet 12 between the two layers of isolation membrane 13, point A is the intersection of the first straight line and the convex contour part of the Nth layer of positive electrode sheet 10, point B is the intersection of the first straight line and the convex contour part of the N+1th layer of positive electrode sheet 11, point C is the intersection of the first straight line and the concave contour part of the N+1th layer of positive electrode sheet 11, point D is the midpoint of the line segment between the intersection of the convex contour part and the concave contour part of the negative electrode sheet 12, and the gap between the positive and negative electrode sheets of the battery cell is the length of the line segment DA, where the length of the line segment DA is equal to the length of the line segment CD.

[0111] By pre-establishing the correspondence between pixels and actual size, the number of pixels in the image can be accurately converted into the actual physical size, thus eliminating the influence of factors such as image resolution and shooting angle, ensuring high-precision measurement results. After the details captured in the image are converted to actual size, the high-precision image resolution is retained, which improves the detail and accuracy of the gap size measurement results.

[0112] In some embodiments, there are two separators and one negative electrode sheet between two adjacent positive electrode sheets, the two separators are located between the two adjacent positive electrode sheets, and the negative electrode sheet is located between the two separators; thus, reference Fig.10As shown, before obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size, the method may further include steps S10 and S20:

[0113] S10, scanning the label on the battery cell to obtain the formula information of the battery cell.

[0114] Exemplarily, the label on the battery cell may include a battery cell barcode. When collecting CT image samples, the battery cell barcode is scanned with a barcode scanner and the barcode information is entered into the production system. When the GAP measurement software imports the sample to be identified, the naming method of the exported sample is pre-specified to unify the position of the battery cell barcode in the sample naming, such as naming the sample in the format of "pull line-variety-battery cell barcode-measurement position". The software reads the battery cell barcode information and measurement position information in the file name. The battery cell barcode can be obtained by a barcode scanner when collecting CT test samples, which can avoid manual input errors. In addition, the software algorithm reading the barcode can check the number of barcode digits to avoid incomplete barcodes.

[0115] For example, the cell barcode can be composed of 18 digits and letters, the first 12 digits represent the base, pull line, variety and other information, and the last 6 digits represent the production date, production number and other information. Since the first 12 digits of the cell barcode of the same product are the same, the formula information of the test sample can be known based on the obtained cell barcode. The GAP measurement software transmits the obtained barcode battery code information to the production system for comparison, and the production system returns the formula information of the cell barcode to the GAP measurement software, thus completing the association of the formula information and realizing automatic formula acquisition for all products, avoiding time-consuming and error-prone manual matching.

[0116] Automatically obtain formula information by scanning the label on the battery cell, reducing the risk of manual input errors. Automatically obtaining formula information can improve the accuracy of the battery cell's formula data and reduce the risk of omissions or errors caused by manual entry.

[0117] S20, obtaining the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet from the formula information of the battery cell.

[0118] In this way, based on the corresponding actual dimensions, obtaining the size of the gap between the positive and negative electrode sheets of the battery cell can include: obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the corresponding actual dimensions, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation membrane, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet.

[0119] By obtaining various parameters in the battery cell formula, such as the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, and the expansion coefficient, the actual gap size of the positive and negative electrode sheets inside the battery cell can be calculated more accurately. This calculation method based on formula parameters can greatly reduce the errors in manual measurement, and take into account dynamic change factors such as material expansion, thereby providing more accurate dimensional data. During the use of the battery cell, the expansion characteristics of the positive and negative electrode sheets and the separator will affect the internal gap size of the battery cell. By introducing the expansion coefficient of the positive and negative electrode sheets in the calculation, the expansion effect of the battery cell under different use conditions can be predicted and compensated, thereby accurately evaluating the gap changes of the battery cell in the actual working environment and reducing performance problems caused by excessive expansion.

[0120] In some embodiments, obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet may include:

[0121] Subtracting the first value, the second value and the third value from the corresponding actual size to obtain a fourth value; the first value is the product of the thickness of the positive electrode sheet and the expansion coefficient of the positive electrode sheet, the second value is the product of the thickness of the negative electrode sheet and the expansion coefficient of the negative electrode sheet, and the third value is twice the thickness of the separator;

[0122] Divide the fourth value by two to get the size of the gap between the positive and negative electrode sheets of the battery cell.

[0123] For example, Figure 8 As an example, the size of the gap between the positive and negative electrodes of the battery cell is GAP = (L AB -α×D 正极极片厚度 -β×d 负极极片厚度 -2*E 隔离膜厚度 ) / 2, where α is the expansion coefficient of the positive electrode, β is the expansion coefficient of the negative electrode, and L AB Represents the corresponding actual size, D 正极极片厚度 Represents the thickness of the positive electrode sheet, d 负极极片厚度 Represents the thickness of the negative electrode sheet, E 隔离膜厚度 represents the thickness of the isolation film. The first value is α×D 正极极片厚度 , β×d 负极极片厚度 is the second value, 2*E 隔离膜厚度 is the third value.

[0124] During the use of the battery cell, the expansion characteristics of the positive and negative pole pieces and the separator will affect the internal gap size of the battery cell. By introducing the expansion coefficients of the positive and negative pole pieces in the calculation, the expansion effect of the battery cell under different use conditions can be predicted and compensated, thereby accurately evaluating the gap changes of the battery cell in the actual working environment and reducing performance problems caused by excessive expansion.

[0125] By considering the various components of the battery cell, such as the positive electrode, negative electrode and separator, as well as their expansion coefficients, the size of the gap between the positive and negative electrode sheets can be calculated more accurately. This precise calculation takes into account the impact of material expansion in actual use, reduces the error that may be caused by simple static size calculations, and thus obtains a more accurate size of the gap between the positive and negative electrode sheets of the battery cell. Through this formulaic calculation method, the size calculation of the gap between the positive and negative electrode sheets of the battery cell during production and testing can be completed automatically, reducing manual intervention and reducing human errors. This automated calculation not only improves work efficiency, but also makes the production process of each battery cell more standardized and standardized, further optimizing the production process.

[0126] In some embodiments, based on the correspondence between the number of pixels and the actual size, before converting the number of gap pixels into the corresponding actual size, the method may further include: identifying the pixel ratio mark on the CT image to obtain the correspondence between the number of pixels and the actual size.

[0127] The pixel ratio mark on the CT image is, for example, 34.85 μm / pixel, that is, each pixel on the CT image corresponds to 34.85 μm in actual size.

[0128] By identifying the pixel ratio mark on the image and obtaining the corresponding relationship between the number of pixels and the actual size, the function of converting the number of gap pixels to the actual size is realized. By accurately identifying the pixel ratio mark, it can be ensured that the conversion relationship between the number of pixels and the actual size is correct and accurate. Regardless of how the resolution of the image changes, this method can accurately convert the pixel values ​​in the image to the actual physical size, thereby reducing the errors that may be introduced by different devices or shooting conditions. By identifying the pixel ratio mark, the calculation ratio can be adjusted before each image processing to adapt to different image resolutions. This makes the method highly versatile and can be widely used in images of different sources and resolutions.

[0129] In some embodiments, the method may further include:

[0130] S60: According to a preset size threshold of the gap between the positive and negative electrode sheets, determine whether the size of the gap between the positive and negative electrode sheets of the battery cell meets the gap control requirement, and obtain a determination result.

[0131] For example, in the GAP measurement software, the GAP criterion threshold can be pre-set in the recipe information as required, and can be set as required according to the different layers of the battery corners. For example, the control can be carried out according to the different layers of the positive electrode sheets, and the gap control requirements can be set to include: the GAP measurement value of the positive electrode sheets of the 1st to 5th layers from the center of the battery cell from the inside to the outside is <T0, the GAP measurement value of the positive electrode sheets of the 6th to 10th layers from the inside to the outside is <T1, and the GAP measurement value of the positive electrode sheets outside the 10th layer from the inside to the outside is <T2; T0, T1 and T2 are all preset size thresholds.

[0132] In some examples, a preset size threshold may also be set for all layers, such as GAP measurement value < T3. This can meet the GAP measurement value control requirements in different scenarios, and the specific threshold setting method can be selected according to actual application needs.

[0133] Through information interaction between the GAP measurement software and the production system, the GAP measurement values, judgment results and algorithm recognition images can be uploaded to the production system with one click, reducing problems such as under-recording, over-recording and incorrect recording caused by manual offline data entry, and improving the efficiency and accuracy of data entry.

[0134] By setting a clear size threshold, it is possible to accurately determine whether the gap between the positive and negative plates of the battery cell meets the design standards. This threshold-based automated detection can reduce human errors and improve the accuracy of the gap size between the positive and negative plates of the battery cell, thereby improving the quality stability of the battery cell and the consistency of the battery cell performance.

[0135] For example, when it is detected that the size of the gap between the positive and negative electrode sheets of the battery cell does not meet the gap control requirements, a prompt message, such as an audible and visual prompt message or a text message prompt, may be issued to remind the staff to take timely processing measures.

[0136] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar parts can be referenced to each other, and for the sake of brevity, they will not be repeated in this article.

[0137] refer to Fig.11 As shown, a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell in a specific example may include the following steps:

[0138] Step 110: Obtain the cell barcode and associate it with the recipe information.

[0139] The formula information includes the thickness and expansion rate of the positive and negative electrodes of the battery, the thickness of the isolation film and its coating, the factory, the wire drawing, the variety, the judgment criteria and other information.

[0140] Specifically, Fig.12As shown, when collecting samples for CT testing, the barcode gun obtains the cell barcode, and the barcode information is entered into the production system. When the GAP measurement software imports the samples to be identified, the naming method of the exported samples is specified to unify the position of the cell barcode in the sample naming. For example, the sample is named in the format of "pull line-variety-cell barcode-measurement position". The software reads the cell barcode information and measurement position information in the file name. The cell barcode is obtained by the barcode gun when collecting samples for CT testing, which can avoid manual input errors. In addition, the software algorithm can read the barcode to check the number of barcode digits to avoid incomplete barcodes.

[0141] The cell barcode consists of 18 digits and letters. The first 12 digits represent the base, wire, variety, etc., and the last 6 digits represent the production date, production number, etc. Since the first 12 digits of the cell barcode for the same product are the same, the formula information of the test sample can be known based on the obtained cell barcode. Fig.12 As shown, the GAP measurement software transmits the obtained barcode information to the production system for comparison, and the production system transmits the formula information of the battery barcode back to the GAP measurement software, thus completing the association of the formula information and realizing automatic formula acquisition for all products, thus avoiding time-consuming and error-prone manual matching.

[0142] Step 120: extract the contour of the positive electrode sheet according to the grayscale difference between the positive and negative electrode sheets in the sample, and obtain the GAP measurement pixel size.

[0143] Pixel size refers to the number of pixels in which the size is measured.

[0144] Specifically, the contour of the positive electrode sheet is extracted: in the CT imaging at the corner of the battery, the bright white is the positive electrode sheet, and the dark gray is the negative electrode sheet. According to the difference in the grayscale of the contours of the positive and negative electrode sheets, since the contour features of the positive electrode sheet are bright white and the contours are clear and obvious, the image processing algorithm is used to extract the contour of the positive electrode sheet, and the contour positions of all positive electrode sheets in the imaging process are obtained. For example, an image denoising algorithm can be used to extract the feature ROI area, that is, the contour of the positive electrode sheet, and the contour line of the positive electrode sheet can be identified by the image processing algorithm. The contour line of the positive electrode sheet is divided into a convex contour line and a concave contour line.

[0145] Step 130: extract the pixel ratio mark in the sample to achieve the conversion of pixel size to measured size.

[0146] The pixel size designation means that each pixel represents the actual measured distance.

[0147] Specifically, in the CT test, the pixel ratio information will be displayed when the upper left corner of the GAP test image is exported. The background color on the image is black and the pixel mark is white. The value of the pixel ratio mark can be easily extracted through color contrast. Combined with the pixel size obtained in the previous step, the distance between the convex contour lines of the two adjacent positive electrode pieces on each angle line is obtained, realizing the conversion of pixel size to measurement size.

[0148] Step 140: Calculate the GAP measurement value between the positive and negative electrode sheets according to the recipe information.

[0149] Specifically, Fig. 9 As shown, taking the angle line in the horizontal direction as an example, its intersection points with the convex contour lines of the Nth and N+1th layers of the positive electrode sheet are points A and B respectively, and its intersection point with the convex contour line of the N+1th layer of the positive electrode sheet is point C. Assume that there is a point D in the horizontal thickness direction of the negative electrode sheet between the Nth and N+1th layers of the positive electrode sheet. According to the battery structure, there is L AD =L CD Therefore, the size of the gap between the adjacent positive and negative electrodes of the battery cell is GAP = (L AB -α×D 正极极片厚度 -β×d 负极极片厚度 -2*E 隔离膜厚度 ) / 2, where α is the expansion coefficient of the positive electrode, β is the expansion coefficient of the negative electrode, and L AB Represents the corresponding actual size, D 正极极片厚度 Represents the thickness of the positive electrode sheet, d 负极极片厚度 Represents the thickness of the negative electrode sheet, E 隔离膜厚度 Represents the thickness of the isolation film.

[0150] Step 150: According to the recipe information, the data is automatically determined and uploaded to the production system with one click.

[0151] The specific implementation process of step 150 may include:

[0152] Automatic data determination: In the GAP measurement software, the GAP judgment threshold can be set as required in the formula information. Considering the different layers of battery corners, it can be set as needed. For example, it can be controlled according to the different layers of the positive electrode: for example, the GAP measurement value of the inner 1-5 layers (referring to the positive electrode) is <T0; the GAP measurement value of the inner 6-10 layers is <T1; the GAP measurement value of >10 layers is <T2; or a unified threshold is set for all layers, and the GAP measurement value is <T3. Meet the GAP measurement value control needs in different scenarios.

[0153] One-click data upload: Through information exchange between the GAP measurement software and the production system, the GAP measurement values, judgment results and algorithm recognition images can be uploaded to the production system with one click, eliminating the need for manual offline data entry to avoid problems such as under-entry, over-entry and wrong entry, thereby improving the efficiency and accuracy of data entry.

[0154] The method for obtaining the gap size between the positive and negative electrode sheets of the battery cell in this example can be applied to the GAP measurement system. Fig.13 As shown, the CT test system may include a sample collection module, an image acquisition module and an image processing module connected in sequence. The sample collection module is used to obtain the cell barcode; the image acquisition module is used to scan and reconstruct the 3D image information of the battery; and the image processing module is used to obtain the 2D image of the cell. The GAP measurement system may include a cell barcode reading module, a recipe configuration and comparison module, a pole piece contour recognition module, an authority setting module, a data display and judgment module and a data one-key upload module. The cell barcode reading module is used to obtain the cell barcode information of the 2D image of the image processing module in the CT test system. The specific process is to manually export the 2D image in the CT operating system, and the cell barcode obtained by the sample collection module is saved in the specified position of the 2D image file name by default. The 2D image is manually opened in the GAP measurement system, and the cell barcode reading module in the GAP measurement system extracts the cell barcode information. The production system mainly includes a recipe library and a data storage module.

[0155] The cell barcode information obtained by the sampling module in the CT test system can be uploaded to the production system through LAN communication. The production system matches the recipe information of the cell barcode according to the recipe library, such as base, factory, wire drawing, variety, system and other information.

[0156] The GAP measurement system can upload the cell barcode information to the production system through the LAN communication, and request the production system to feedback the formula information. According to the uniqueness of the formula information fed back by the production system, the formula configuration and comparison module in the GAP measurement system are used to associate the criterion information. As shown in step 110, the formula information is automatically obtained, avoiding the time-consuming and error-prone manual formula matching.

[0157] The GAP measurement system can automatically identify the positive electrode piece contour in the 2D image exported by the CT test system, as shown in step 120, to obtain the GAP measurement pixel size. In step 130, the GAP measurement system can also capture the pixel ratio mark in the 2D image and realize the conversion of pixel size to measurement size. Automatic recognition avoids manual subjective labeling, greatly improving the test efficiency and accuracy of the pole piece contour capture.

[0158] The GAP measurement system can set permissions. Operator and administrator permissions can be set in the software to ensure that formula information can only be modified by administrators, preventing front-line operators from arbitrarily changing formula information and causing test abnormalities.

[0159] The GAP measurement system recipe configuration and comparison module includes parameters such as the thickness and expansion rate of the positive and negative electrode sheets, the thickness of the isolation film, etc. Through the calculation formula in step 140, the automatic calculation of the GAP measurement value between the positive and negative electrode sheets is realized, avoiding the situation of wrong recording, over-recording, under-recording, etc. of the offline table collection data, and also improving the efficiency of data processing. In addition, the formula configuration and comparison module can define the judgment basis according to the needs to realize the automatic judgment of the GAP measurement value OK or NG. Through the data display and judgment module, the data of different measurement positions in the horizontal, positive and negative directions can be displayed by color. When the data is NG, all abnormal positions and abnormal values ​​will be displayed, realizing the synchronous display of the measurement data and the judgment results, solving the lagging situation that the measurement results can only be obtained after the measurement data is converted offline. In step 150, the GAP measurement system uploads the GAP measurement value and the judgment result to the production system through the local area network communication, avoiding the problems of under-recording, over-recording, and wrong recording in the manual offline data entry, and improving the efficiency and accuracy of data entry.

[0160] The method of the embodiment of the present application has achieved stable industrial application. The method of the embodiment of the present application reduces the average test efficiency from 300S / battery to 40.8S / battery, increases the efficiency by about 7 times, and significantly improves the test efficiency. In addition, automatic identification measurement can significantly improve measurement accuracy and consistency compared to manual labeling measurement.

[0161] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0162] refer to Fig.14 As shown, another embodiment of the present application provides a device for obtaining the gap size between the positive and negative electrode sheets of a battery cell, which may include:

[0163] An image acquisition module, used to acquire a computer tomography image of the battery cell; the plane shown in the image is perpendicular to the length direction of the battery cell;

[0164] A gap pixel number acquisition module is used to acquire the number of gap pixels between the contours of two adjacent positive electrode sheets in the image;

[0165] The gap size acquisition module is used to obtain the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels.

[0166] Exemplarily, the gap pixel number acquisition module may include:

[0167] The contour acquisition submodule is used to obtain the contour of each pole piece in the image;

[0168] The pixel number acquisition submodule is used to acquire the number of gap pixels between the contours of two adjacent positive electrode pieces based on the contours of each electrode piece.

[0169] Exemplarily, the pixel number acquisition submodule is further specifically used for:

[0170] Draw a first straight line on the image, the first straight line passes through the starting point of the convex surface contour of the first folded positive electrode piece of the battery cell, and the first straight line intersects with the contours of each electrode piece;

[0171] According to the intersection point between the first straight line and the contours of the two adjacent positive electrode sheets, the number of gap pixels between the contours of the two adjacent positive electrode sheets is obtained.

[0172] Exemplarily, the gap size acquisition module may include:

[0173] A conversion submodule, used for converting the number of gap pixels into the corresponding actual size according to the corresponding relationship between the number of pixels and the actual size;

[0174] The size acquisition submodule is used to obtain the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size.

[0175] Exemplarily, there are two separators and one negative electrode sheet between two adjacent positive electrode sheets, the two separators are located between the two adjacent positive electrode sheets, and the negative electrode sheet is located between the two separators.

[0176] Exemplarily, the device further comprises:

[0177] A scanning module is used to scan the label on the battery cell to obtain the formula information of the battery cell;

[0178] The parameter extraction module is used to obtain the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation film, the expansion coefficient of the positive electrode sheet and the expansion coefficient of the negative electrode sheet from the formula information of the battery cell.

[0179] Specifically, the parameter extraction module is used to obtain the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation film, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet from the formula information of the battery cell before the size acquisition submodule obtains the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size.

[0180] The size acquisition submodule can be further used to obtain the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation membrane, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet.

[0181] The size acquisition submodule can be further used for:

[0182] Subtracting the first value, the second value and the third value from the corresponding actual size to obtain a fourth value; the first value is the product of the thickness of the positive electrode sheet and the expansion coefficient of the positive electrode sheet, the second value is the product of the thickness of the negative electrode sheet and the expansion coefficient of the negative electrode sheet, and the third value is twice the thickness of the separator;

[0183] Divide the fourth value by two to get the size of the gap between the positive and negative electrode sheets of the battery cell.

[0184] Exemplarily, the contour acquisition submodule may include:

[0185] A contour region acquisition unit, used to acquire a contour region of each positive electrode piece according to the grayscale of the positive electrode piece and the negative electrode piece in the image;

[0186] The region of interest extraction unit is used to extract the region of interest from the contour area of ​​each positive electrode piece to obtain the contour of each positive electrode piece.

[0187] Exemplarily, the device may further include:

[0188] The pixel ratio identification module is used to identify the pixel ratio identification on the image and obtain the corresponding relationship between the number of pixels and the actual size.

[0189] Exemplarily, the device may further include a judgment module, which is used to judge whether the size of the gap between the positive and negative electrode sheets of the battery cell meets the gap control requirements based on a preset size threshold of the gap between the positive and negative electrode sheets, and obtain a judgment result.

[0190] The device for acquiring the gap size between the positive and negative electrode sheets of a battery cell in the embodiment of the present application can acquire the number of gap pixels between the outlines of two adjacent positive electrode sheets in an image, and acquire the size of the gap between the positive and negative electrode sheets of the battery cell based on the number of gap pixels, thereby realizing automatic acquisition of the gap size between the positive and negative electrode sheets of the battery cell, greatly improving the consistency and accuracy of the measurement results, reducing the missed kill rate, and greatly improving work efficiency.

[0191] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0192] Another embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method of any of the above embodiments.

[0193] refer to Fig.15As shown, the electronic device 10 may include: a processor 100, a memory 101, a bus 102 and a communication interface 103, and the processor 100, the communication interface 103 and the memory 101 are connected via the bus 102; the memory 101 stores a computer program that can be run on the processor 100, and when the processor 100 runs the computer program, it executes the method provided in any of the aforementioned embodiments of the present application.

[0194] The memory 101 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage. The communication connection between the device network element and at least one other network element is realized through at least one communication interface 103 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0195] The bus 102 may be an ISA bus, a PCI bus, or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory 101 is used to store a program, and the processor 100 executes the program after receiving an execution instruction. The method disclosed in any implementation of the aforementioned embodiment of the present application may be applied to the processor 100, or implemented by the processor 100.

[0196] The processor 100 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor 100 or an instruction in the form of software. The above processor 100 may be a general-purpose processor, which may include a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module may be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 101, and the processor 100 reads the information in the memory 101 and completes the steps of the above method in combination with its hardware.

[0197] The electronic device provided in the embodiment of the present application and the method provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, operated or implemented by them.

[0198] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0199] Another embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored, and the computer program is executed by a processor to implement the method of any of the above embodiments. Fig.16 As shown, the computer-readable storage medium shown is a CD 20 on which a computer program (ie, a program product) is stored. When the computer program is run by a processor, the method provided by any of the aforementioned embodiments will be executed.

[0200] It should be noted that examples of computer-readable storage media may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0201] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0202] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0203] It should be noted that:

[0204] The term "module" is not intended to be limited to a specific physical form. Depending on the specific application, a module can be implemented as hardware, firmware, software, and / or a combination thereof. In addition, different modules can share common components or even be implemented by the same components. There may or may not be clear boundaries between different modules.

[0205] The algorithm and display provided herein are not inherently related to any specific computer, virtual device or other equipment. Various general devices can also be used together with examples based on this. According to the above description, it is obvious to construct the structure required for this type of device. In addition, the application is not directed to any specific programming language yet. It should be understood that various programming languages ​​can be utilized to realize the content of the application described herein, and the description made to specific languages ​​above is for the purpose of disclosing the best mode of implementation of the application.

[0206] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0207] The above embodiments only express the implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for obtaining the gap size between positive and negative electrode sheets of a battery cell, characterized in that: include: Acquire a computer tomography image of the battery cell; the plane shown in the image is perpendicular to the length direction of the battery cell; Obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the image; According to the number of gap pixels, the size of the gap between the positive and negative electrode sheets of the battery cell is obtained.

2. The method according to claim 1, characterized in that: The step of obtaining the number of gap pixels between the contours of two adjacent positive electrode sheets in the image includes: Obtaining the contour of each pole piece in the image; Based on the contours of the pole pieces, the number of gap pixels between the contours of two adjacent positive pole pieces is obtained.

3. The method according to claim 2, characterized in that The step of obtaining the number of gap pixels between the contours of two adjacent positive electrode pieces based on the contours of the electrode pieces includes: Draw a first straight line on the image, the first straight line passes through the starting point of the convex surface contour of the first folded positive electrode piece of the battery cell, and the first straight line intersects with the contour of each electrode piece; According to the intersection of the first straight line and the contours of the two adjacent positive electrode sheets, the number of gap pixels between the contours of the two adjacent positive electrode sheets is obtained.

4. The method according to any one of claims 1 to 3, characterized in that The obtaining, according to the number of gap pixels, the size of the gap between the positive and negative electrode sheets of the battery cell comprises: According to the corresponding relationship between the number of pixels and the actual size, the number of gap pixels is converted into the corresponding actual size; Based on the corresponding actual size, the size of the gap between the positive and negative electrode sheets of the battery cell is obtained.

5. The method according to claim 4, characterized in that There are two separators and one negative electrode sheet between the two adjacent positive electrode sheets, the two separators are located between the two adjacent positive electrode sheets, and the negative electrode sheet is located between the two separators; Before obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size, the method further includes: Scan the label on the battery cell to obtain the formula information of the battery cell; Acquire the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet, and the expansion coefficient of the negative electrode sheet from the formula information of the battery cell; The obtaining the size of the gap between the positive and negative electrode sheets of the battery cell based on the corresponding actual size includes: The size of the gap between the positive and negative electrode sheets of the battery cell is obtained according to the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the isolation membrane, the expansion coefficient of the positive electrode sheet and the expansion coefficient of the negative electrode sheet.

6. The method according to claim 5, characterized in that The obtaining the size of the gap between the positive and negative electrode sheets of the battery cell according to the corresponding actual size, the thickness of the positive electrode sheet, the thickness of the negative electrode sheet, the thickness of the separator, the expansion coefficient of the positive electrode sheet and the expansion coefficient of the negative electrode sheet comprises: Subtracting the first value, the second value and the third value from the corresponding actual size to obtain a fourth value; the first value is the product of the thickness of the positive electrode sheet and the expansion coefficient of the positive electrode sheet, the second value is the product of the thickness of the negative electrode sheet and the expansion coefficient of the negative electrode sheet, and the third value is twice the thickness of the isolation film; The fourth value is divided by two to obtain the size of the gap between the positive and negative electrode sheets of the battery cell.

7. The method according to claim 2, characterized in that The obtaining of the contour of each pole piece in the image comprises: Acquire a contour area of ​​each positive electrode piece according to the grayscale of the positive electrode piece and the negative electrode piece in the image; The region of interest is extracted from the contour area of ​​each positive electrode piece to obtain the contour of each positive electrode piece.

8. The method according to claim 4, characterized in that Before converting the number of gap pixels into the corresponding actual size according to the correspondence between the number of pixels and the actual size, the method further includes: The pixel ratio mark on the image is identified to obtain the corresponding relationship between the number of pixels and the actual size.

9. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: According to the preset size threshold of the gap between the positive and negative electrode sheets, it is judged whether the size of the gap between the positive and negative electrode sheets of the battery cell meets the gap control requirements, and a judgment result is obtained.

10. A device for obtaining the gap size between positive and negative electrode sheets of a battery cell, characterized in that: include: An image acquisition module, used to acquire a computer tomography image of the battery cell; the plane shown in the image is perpendicular to the length direction of the battery cell; A gap pixel number acquisition module is used to acquire the number of gap pixels between the outlines of two adjacent positive electrode sheets in the image; The gap size acquisition module is used to acquire the size of the gap between the positive and negative electrode sheets of the battery cell according to the number of gap pixels.

11. An electronic device, characterized in that: It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for obtaining the gap size between the positive and negative electrode sheets of a battery cell as described in any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the method for obtaining the gap size between the positive and negative electrode sheets of a battery cell as described in any one of claims 1-9.

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