Methods for testing the verticality of the insulating film openings in battery cells and battery cell specifications.

Abstract

This invention relates to the field of battery technology, and discloses a method for detecting the verticality of window openings in the insulating film of a battery cell, as well as the battery cell itself. The detection method includes: arbitrarily selecting at least three columns of windows and acquiring image information of the windows using a two-dimensional image measuring instrument; based on the acquired image information, forming a line image of the windows on the display screen of the two-dimensional image measuring instrument using an image processing model; determining the center line of the opening in the window along the width direction of the insulating film, or the line connecting the centers of two openings in the window along the width direction of the insulating film, using the image processing model; determining the perpendicular line of the window in the width direction using the image processing model; acquiring the distance value A between multiple points on the center line or the center line and the corresponding perpendicular line in the length direction using the image processing model; and comparing all acquired distance values ​​A with a preset deviation value. Based on the comparison result between A and the preset deviation value, insulating films with unqualified window verticality can be screened out in advance.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to a method for detecting the verticality of the window opening in the insulating film of a battery cell and the battery cell itself. Background Technology

[0002] New energy batteries are widely used in various fields such as transportation power supply, power storage power supply, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high working voltage, strong charge retention capacity and long cycle life.

[0003] A battery pack typically consists of multiple battery cells, which are fixed inside the pack's casing. A battery cell generally includes a cover, casing, electrode assembly, electrode assembly end plates, bare cell insulating sheets, insulating film (such as blue film), and a cover plate top patch. The cover is welded to the casing and forms a sealed space protecting the electrode assembly. The bare cell insulating sheets cover the electrode assembly to protect it and prevent short circuits caused by contact between the electrode assembly and the casing. The electrode assembly end plates secure the tabs and provide space for their protection. The insulating film mainly covers the outside of the casing, providing external insulation.

[0004] In general, in order to securely assemble multiple cells inside the battery pack, structural adhesive is usually applied between two adjacent cells and between multiple cells and the inner wall of the battery pack, so as to bond and fix the cells inside the battery pack.

[0005] However, during battery pack use, insufficient adhesion at the bonding points between the insulating film and structural adhesive can lead to bonding failure, affecting the long-term reliability of the battery cells. Therefore, multiple openings are typically incorporated into the insulating film to allow some structural adhesive to directly bond to the cell casing, thereby improving bonding strength. However, during production, factors such as tension can cause the insulating film to tilt, meaning the distance between the center line of the opening and the theoretical vertical line of the insulating film is too large. This can lead to poor insulation withstand voltage testing after the battery cells are encapsulated. Summary of the Invention

[0006] In view of this, the present invention provides a method for detecting the verticality of the insulating film opening of a battery cell and a battery cell, so as to solve the problem that the insulation withstand voltage test is prone to occur after the battery cell is coated due to the tilt of the insulating film opening.

[0007] In a first aspect, the present invention provides a method for detecting the verticality of windows in the insulating film of a battery cell, wherein the surface of the insulating film is provided with multiple rows of windows spaced apart along its length, each of the windows including multiple openings spaced apart along its width, and the detection method includes:

[0008] At least three columns of the windows are arbitrarily selected, and image information of the selected windows is obtained using a two-dimensional image measuring instrument;

[0009] Based on the acquired image information of the window, the image processing model of the two-dimensional image measuring instrument is used to form a line image of the window on the display screen of the two-dimensional image measuring instrument.

[0010] The image processing model is used to determine the center line of the opening in the window along the width direction of the insulating film, or the line connecting the centers of two openings in the window along the width direction of the insulating film; the image processing model is used to determine the perpendicular line of the window along the width direction of the insulating film.

[0011] The image processing model is used to obtain the spacing value A between multiple points on the center line or the center line and the corresponding perpendicular line in the length direction of the insulating film.

[0012] Compare all the acquired spacing values ​​A with the preset deviation value;

[0013] If all spacing values ​​A are less than the preset deviation value, then the verticality of the window opening of the insulating film meets the design requirements.

[0014] If any spacing value A is greater than or equal to the preset deviation value, the verticality of the window opening of the insulating film does not meet the design requirements.

[0015] Beneficial Effects: This invention selects at least three columns of windows, acquires images using a two-dimensional image measuring instrument, and converts them into line images. Then, an image processing model is used to determine the spacing value A between the center line, the line connecting the centers, and the vertical line. The spacing value A is then compared with a preset deviation value to detect verticality, accurately quantifying the window verticality deviation. Furthermore, since the detection process uses the spacing values ​​of multiple columns of windows and multiple points as references, it improves the comprehensiveness and accuracy of the detection. Therefore, the detection method provided by this invention can pre-screen insulating film materials with substandard window verticality, effectively reducing the probability of poor insulation withstand voltage testing after subsequent cell encapsulation.

[0016] In one optional implementation, the preset deviation value is 0.5 mm; the comparison of all acquired spacing values ​​A with the preset deviation value includes:

[0017] Compare all the obtained spacing values ​​A with 0.5 mm;

[0018] If all spacing values ​​A are less than 0.5 mm, then the verticality of the window opening of the insulating film meets the design requirements;

[0019] If any spacing value A is greater than or equal to 0.5 mm, the verticality of the window opening of the insulating film does not meet the design requirements.

[0020] Beneficial effects: By setting a preset deviation value of 0.5mm, this invention not only provides a clear and unified quantitative standard for testing, avoiding subjective judgment errors, but also accurately controls the deviation range of window verticality, ensuring that non-compliant insulation films are screened out in a timely manner. This effectively reduces the risk of insulation failure caused by non-compliant window verticality, and ensures the quality stability and consistency of battery cell production.

[0021] In one optional implementation, the two-dimensional image measuring instrument includes an optical lens and a camera transmission system; acquiring the selected window image information using the two-dimensional image measuring instrument includes:

[0022] The optical lens is used to magnify and image the window;

[0023] The magnified image information of the window is transmitted to the display screen using the camera transmission system.

[0024] Beneficial effects: This invention utilizes an optical lens to magnify and image the window opening, clearly enlarging the details and ensuring the clarity and accuracy of the image information. This provides a high-quality image foundation for the subsequent image processing model to accurately determine the center line, vertical line, and spacing value A, thereby improving detection accuracy and ensuring the reliability of the window opening verticality detection results. Furthermore, using a camera transmission system to transmit the magnified window opening image information to the display screen enables rapid and stable transmission of image information. This ensures that the image processing model on the display screen can perform analysis and calculations based on a complete and clear image, reducing image distortion or information loss during transmission.

[0025] In one optional implementation, the opening is square in shape; determining the center line of the opening in the window along the width direction of the insulating film or the center line connecting two openings in the window along the width direction of the insulating film using the image processing model includes:

[0026] Arbitrarily select line images of at least three of the openings in the window, and use the image processing model to determine the center line of the selected opening in the width direction of the insulating film.

[0027] Beneficial effects: The regular outline of the square opening makes it easier for the image processing model to accurately identify the line boundary, and the centerline data of at least three openings can form an effective reference, which can reduce errors and ensure the reliability of subsequent perpendicularity detection results.

[0028] In one optional implementation, determining the centerline of the selected opening in the width direction of the insulating film using the image processing model includes:

[0029] The image processing model is used to determine the center point of a pair of edge lines of the opening in the width direction of the insulating film;

[0030] The image processing model is used to connect a pair of center points to form the center line.

[0031] Beneficial effects: This invention determines the center point of a pair of edges in the width direction of the open line image through an image processing model, and then connects the two center points to form a center line. This method of accurately locating the center point based on the edges ensures the objectivity and accuracy of the center line position, avoids the deviation that may be caused by manually setting the benchmark, and improves the reliability and standardization of the entire detection process.

[0032] In one optional implementation, determining the center points of a pair of edges of the opening's line image in the width direction of the insulating film using the image processing model includes:

[0033] The two endpoints of the edge are selected using the image processing model to obtain the center point of the edge.

[0034] Beneficial effects: By utilizing the inherent functions of the image processing model, the center point of the edge can be automatically generated after selecting the two endpoints of the edge. This process not only reduces the errors that may be caused by human operation, but also improves the efficiency of center point determination.

[0035] In one optional implementation, the opening is circular; determining the center line of the opening in the window along the width direction of the insulating film or the center line connecting two openings in the window along the width direction of the insulating film using the image processing model includes:

[0036] Arbitrarily select line images of at least three openings in the window, and use the image processing model to select the line image corresponding to the selected opening to obtain the center of the circle corresponding to the opening;

[0037] The image processing model is used to connect the center of one of the openings to the center of the other openings to form the center line.

[0038] Beneficial effects: By connecting the centers of two openings, this invention can accurately and efficiently determine the center line along the width of the insulating film, improving the accuracy and reliability of the center line determination and providing a precise benchmark for subsequent operations. Furthermore, selecting line images from at least three openings can reduce errors and ensure the reliability of subsequent perpendicularity detection results.

[0039] In one optional implementation, determining the perpendicular line of the window opening in the width direction of the insulating film using the image processing model includes:

[0040] Using the image processing model, a straight line perpendicular to the side of the insulating film in its width direction is drawn from the starting point or ending point of the center line or the line connecting the centers to form the perpendicular line.

[0041] Beneficial effects: This invention uses an image processing model to draw a straight line perpendicular to the side of the insulating film's width direction from the starting point or ending point of the center line or the line connecting the centers. Using the side of the insulating film as a stable reference, combined with the precise position of the endpoint of the center line or the line connecting the centers, the standardization and accuracy of the vertical line direction are ensured. This makes the relative positional relationship between the vertical line and the center line or the line connecting the centers more accurate, providing a reliable baseline for subsequent spacing value A measurement, and further improving the accuracy of verticality detection.

[0042] In one optional implementation, the detection method further includes:

[0043] The length L of the window in the width direction of the insulating film is determined using the image processing model.

[0044] Compare 2*A / L with 0.0025;

[0045] If 2*A / L is less than or equal to 2*A / L, then the verticality of the window opening of the insulating film meets the design requirements;

[0046] If 2*A / L is greater than 0.0025, then the verticality of the window opening of the insulating film does not meet the design requirements.

[0047] Beneficial effects: This invention determines the length L in the window width direction using an image processing model, and compares 2*A / L with 0.0025 to determine whether the verticality is qualified. This proportional judgment method based on length L eliminates the influence of different window sizes on deviation assessment, realizing the relative and standardized measurement of deviation. Compared with simple absolute deviation value comparison, it is more in line with the detection needs of different window specifications in actual production, further improving the scientificity and applicability of the detection, and providing a more accurate and flexible evaluation standard for the quality control of the verticality of insulating film windows.

[0048] Secondly, the present invention also provides a battery cell, comprising:

[0049] The battery cell housing has a pair of large surfaces and a pair of narrow sides arranged opposite to each other;

[0050] The insulating film is an insulating film that meets the design requirements after being tested by the above-mentioned testing method; the insulating film wraps around the periphery of the cell housing, and the opening of the insulating film is located on the narrow side of the cell housing; along the setting direction of the pair of narrow side surfaces, the distance from the edge of the opening to the distance corresponding to the large surface is a, and the relationship between A and a satisfies: A / a≤0.15.

[0051] Beneficial effects: The battery cell of the present invention uses an insulating film that has been confirmed to be qualified by the above-mentioned testing method, and the distance 'a' between the edge of the window and the large surface and the spacing value A are limited to satisfy A / a≤0.15. In this way, it can not only ensure that the surface of the battery cell is wrapped with a qualified insulating film, but also avoid the risk of short circuit caused by insufficient insulation distance between the large surface and the edge of the window due to the deviation of the window position, thereby improving the structural stability and safety of the battery cell. Attached Figure Description

[0052] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the structure of an insulating film according to an embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of another insulating film structure according to an embodiment of the present invention;

[0055] Figure 3 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of another battery cell according to an embodiment of the present invention.

[0057] Explanation of reference numerals in the attached figures:

[0058] 1. Large surface; 2. Narrow side surface; 3. Insulating film; 301. Window opening; 3011. Opening; 4. Center line; 5. Vertical line; 6. Center line. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] To address the problem that tilted openings in the insulating film can lead to poor insulation withstand voltage tests after cell encapsulation, this invention provides a method for detecting the verticality of the insulating film openings in a battery cell, as well as the battery cell itself.

[0061] The following is combined Figures 1 to 4 The following describes embodiments of the present invention.

[0062] According to embodiments of the present invention, such as Figure 1 and Figure 2 As shown, on one hand, a method for detecting the perpendicularity of the window 301 of the insulating film 3 of a battery cell is provided. The surface of the insulating film 3 has multiple rows of windows 301 spaced apart along its length direction. Each window 301 includes multiple openings 3011 spaced apart along its width direction. The detection method includes:

[0063] At least three columns of windows 301 are randomly selected, and the image information of the selected windows 301 is obtained using a two-dimensional image measuring instrument.

[0064] Based on the acquired image information of window 301, the image processing model of the two-dimensional image measuring instrument is used to form a line image of window 301 on the display screen of the two-dimensional image measuring instrument.

[0065] The image processing model is used to determine the center line 4 of the window 301 in the width direction of the insulating film 3 or the center line connecting the two openings 3011 in the window 301 in the width direction of the insulating film 3; the image processing model is used to determine the perpendicular line 5 of the window 301 in the width direction of the insulating film 3.

[0066] The spacing value A between multiple points on the center line 4 or the center connecting line 6 and the corresponding perpendicular line 5 along the length of the insulating film 3 is obtained using an image processing model.

[0067] Compare all the acquired spacing values ​​A with the preset deviation value;

[0068] If all spacing values ​​A are less than the preset deviation value, then the verticality of the opening 301 of the insulating film 3 meets the design requirements;

[0069] If any spacing value A is greater than or equal to the preset deviation value, the verticality of the opening 301 of the insulating film 3 does not meet the design requirements.

[0070] This invention employs at least three columns of windowed sections 301, acquires images using a two-dimensional image measuring instrument, and converts them into line images. Then, an image processing model is used to determine the spacing value A between the center line 4, the center connecting line 6, and the vertical line 5. The spacing value A is then compared with a preset deviation value to detect the verticality deviation of the windowed sections 301, enabling precise quantification of the verticality deviation. Furthermore, since the detection process uses the spacing values ​​of multiple columns of windowed sections 301 and multiple points as references, the comprehensiveness and accuracy of the detection are improved. Therefore, the detection method provided by this invention can pre-screen incoming insulating film 3 materials with substandard windowed section verticality, thereby effectively reducing the probability of poor insulation withstand voltage testing after subsequent cell encapsulation.

[0071] It should be noted that the two-dimensional image measuring instrument in this embodiment is a two-dimensional precision measuring instrument that combines optical imaging, mechanical transmission, and computer image processing in the prior art. The image processing model used in the two-dimensional image measuring instrument can be, but is not limited to, image processing models such as Metus, M2D-IMG Measurement software, PRECIV, and GSAImage Analyser.

[0072] According to one embodiment of the present invention, the preset deviation value is 0.5 mm; comparing all the obtained spacing values ​​A with the preset deviation value includes: comparing all the obtained spacing values ​​A with 0.5 mm; if all spacing values ​​A are less than 0.5 mm, then the verticality of the window 301 of the insulating film 3 meets the design requirements; if any spacing value A is greater than or equal to 0.5 mm, then the verticality of the window 301 of the insulating film 3 does not meet the design requirements. By specifying a preset deviation value of 0.5 mm, this embodiment of the present invention not only provides a clear and unified quantitative standard for testing, avoiding subjective judgment errors, but also accurately controls the deviation range of the verticality of the window 301, ensuring that non-compliant insulating films 3 are promptly screened out. This effectively reduces the risk of insulation failure caused by non-compliant verticality of the window 301, ensuring the quality stability and consistency of battery cell production.

[0073] According to one embodiment of the present invention, a two-dimensional image measuring instrument includes an optical lens and a camera transmission system. Acquiring image information of a selected window 301 using the two-dimensional image measuring instrument includes: magnifying and imaging the window 301 using the optical lens; and transmitting the magnified image information of the window 301 to a display screen using the camera transmission system. This embodiment of the invention utilizes an optical lens to magnify and image the window 301, clearly magnifying the details of the window 301, ensuring the clarity and accuracy of the image information. This provides a high-quality image foundation for the subsequent image processing model to accurately determine the center line 4, the vertical line 5, and the spacing value A, thereby improving detection accuracy and ensuring the reliability of the perpendicularity detection results of the window 301. Furthermore, using the camera transmission system to transmit the magnified image information of the window 301 to the display screen enables rapid and stable transmission of image information, ensuring that the image processing model on the display screen can perform analysis and calculations based on a complete and clear image, reducing image distortion or information loss during transmission.

[0074] It should be noted that the camera transmission system in this embodiment may be, but is not limited to, a CCD (Charge Coupled Device) camera system.

[0075] According to one embodiment of the present invention, such as Figure 1 As shown, the opening 3011 is square. Determining the centerline 4 of the window 301 along the width of the insulating film 3, or the centerline 6 connecting the centers of two openings 3011 along the width of the insulating film 3, using an image processing model, includes: arbitrarily selecting line images of at least three openings 3011 within the window 301, and using the image processing model to determine the centerline 4 of the selected opening 3011 along the width of the insulating film 3. It can be understood that the regular contour of the square opening 3011 facilitates accurate line boundary identification by the image processing model, while the centerline 4 data of at least three openings 3011 form a valid reference, reducing errors and ensuring the reliability of subsequent perpendicularity detection results.

[0076] Specifically, in this embodiment, the opening 3011 is rectangular in shape, wherein the length direction of the opening 3011 is consistent with the width direction of the insulating film 3, and the width direction of the opening 3011 is consistent with the length direction of the insulating film 3.

[0077] According to one embodiment of the present invention, determining the center line 4 of the selected opening 3011 in the width direction of the insulating film 3 using an image processing model includes: determining the center points of a pair of edge lines of the line image of the opening 3011 in the width direction of the insulating film 3 using an image processing model; and connecting the pair of center points using an image processing model to form the center line 4. This embodiment of the present invention determines the center points of a pair of edge lines in the width direction of the line image of the opening 3011 using an image processing model, and then connects the two center points to form the center line 4. This method of accurately locating the center point based on the edge lines ensures the objectivity and accuracy of the center line 4's position, avoids deviations that may occur due to manually setting a reference, and improves the reliability and standardization of the entire detection process.

[0078] According to one embodiment of the present invention, determining the center point of a pair of edges of the line image of the opening 3011 in the width direction of the insulating film 3 using an image processing model includes: selecting the two endpoints of the edges using the image processing model to obtain the center point of the edges. Utilizing the inherent function of the image processing model, after selecting the two endpoints of the edges, the center point of the edges can be automatically generated. This process not only reduces errors that may be caused by manual operation but also improves the efficiency of center point determination.

[0079] According to one embodiment of the present invention, such as Figure 2 As shown, the opening 3011 is circular. Determining the center line 4 of each opening 3011 in the width direction of the insulating film 3, or the center line 6 connecting two openings 3011 in the width direction of the insulating film 3, using an image processing model, includes: arbitrarily selecting line images of at least three openings 3011 in the window 301; using an image processing model to determine the line image corresponding to the selected opening 3011 to obtain the center of the circle corresponding to the opening 3011; and using an image processing model to connect the center of one opening 3011 with the centers of the other openings 3011 to form the center line 6. This embodiment of the invention connects the centers of two openings 3011, which can accurately and efficiently determine the center line 6 in the width direction of the insulating film 3, improving the accuracy and reliability of the center line 6 determination and providing a precise benchmark for subsequent related operations. Selecting line images of at least three openings 3011 can reduce errors and ensure the reliability of subsequent perpendicularity detection results.

[0080] It is understandable that when the opening 3011 is square, the same detection scheme as for the circular opening 3011 can be used, that is, first determine the center point of the opening 3011, and then connect the center points of the two openings 3011 to form a center line. The process of obtaining the center point of the square opening 3011 is as follows: using an image processing model, determine the center points of a pair of edge lines in the width direction and a pair of edge lines in the length direction of the insulating film 3 of the line image of the opening 3011. Then connect the center points in the width direction and the length direction respectively. The intersection of the two lines is the center point corresponding to the square opening 3011.

[0081] According to one embodiment of the present invention, determining the perpendicular line 5 of the window 301 in the width direction of the insulating film 3 using an image processing model includes: drawing a straight line perpendicular to the side edge of the insulating film 3 in its width direction from the starting point or ending point of the center line 4 or the center connecting line 6 using an image processing model to form the perpendicular line 5. This embodiment of the present invention uses an image processing model to draw a straight line perpendicular to the side edge of the insulating film 3 in the width direction from the starting point or ending point of the center line 4 or the center connecting line 6 as the perpendicular line 5. Using the stable reference of the side edge of the insulating film 3, combined with the precise position of the endpoint of the center line 4 or the center connecting line 6, ensures the standardization and accuracy of the direction of the perpendicular line 5, making the relative positional relationship between the perpendicular line 5 and the center line 4 or the center connecting line 6 more accurate. This provides a reliable baseline for subsequent measurement of the spacing value A, further improving the accuracy of perpendicularity detection.

[0082] According to one embodiment of the present invention, the detection method further includes: determining the length L of the window 301 in the width direction of the insulating film 3 using an image processing model; comparing 2*A / L with 0.0025; if 2*A / L is less than or equal to 2*A / L, the perpendicularity of the window 301 of the insulating film 3 meets the design requirements; if 2*A / L is greater than 0.0025, the perpendicularity of the window 301 of the insulating film 3 does not meet the design requirements. This embodiment of the present invention determines the length L in the width direction of the window 301 using an image processing model and compares 2*A / L with 0.0025 to determine whether the perpendicularity is qualified. This proportional judgment method based on length L can eliminate the influence of different window 301 sizes on deviation evaluation, realizing the relative and standardized measurement of deviation. Compared with simple absolute deviation value comparison, it is more in line with the detection needs of different specifications of window 301 in actual production, further improving the scientificity and applicability of the detection, and providing a more accurate and flexible evaluation standard for the quality control of the perpendicularity of the window 301 of the insulating film 3.

[0083] According to an embodiment of the present invention, on the other hand, such as Figure 3 and Figure 4As shown, a battery cell is also provided, comprising: a battery cell housing having a pair of large surfaces 1 and a pair of narrow side surfaces 2 arranged opposite to each other; an insulating film 3, which is an insulating film 3 that meets the design requirements after being tested by the above-mentioned testing method; the insulating film 3 is wrapped around the periphery of the battery cell housing, and the opening 301 of the insulating film 3 is located on the narrow side surface 2 of the battery cell housing; along the setting direction of the pair of narrow side surfaces 2, the distance from the edge of the opening 301 to the corresponding large surface 1 is a, and the relationship between A and a satisfies: A / a≤0.15. In this embodiment of the invention, the battery cell uses an insulating film 3 that has been confirmed to be qualified by the above-mentioned testing method, and the distance a from the edge of the opening 301 to the large surface 1 is limited to the spacing value A satisfying A / a≤0.15. In this way, it can not only ensure that the surface of the battery cell housing is wrapped with a qualified insulating film 3, but also avoid the risk of short circuit caused by insufficient insulation distance between the large surface 1 and the edge of the opening 301 due to the positional deviation of the opening 301, thereby improving the structural stability and safety of the battery cell.

[0084] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for detecting the verticality of windows in an insulation film of an electric cell, the surface of the insulation film being provided with a plurality of rows of windows spaced apart along the length direction thereof, any of the windows comprising a plurality of openings spaced apart along the width direction thereof, characterized in that, The detection method includes: At least three columns of the windows are arbitrarily selected, and image information of the selected windows is obtained using a two-dimensional image measuring instrument; Based on the acquired image information of the window, the image processing model of the two-dimensional image measuring instrument is used to form a line image of the window on the display screen of the two-dimensional image measuring instrument. The image processing model is used to determine the center line of the opening in the window along the width direction of the insulating film, or the line connecting the centers of two openings in the window along the width direction of the insulating film; the image processing model is used to determine the perpendicular line of the window along the width direction of the insulating film. The image processing model is used to obtain the spacing value A between multiple points on the center line or the center line and the corresponding perpendicular line in the length direction of the insulating film. Compare all the acquired spacing values ​​A with the preset deviation value; If all spacing values ​​A are less than the preset deviation value, then the verticality of the window opening of the insulating film meets the design requirements. If any spacing value A is greater than or equal to the preset deviation value, the verticality of the window opening of the insulating film does not meet the design requirements.

2. The detection method according to claim 1, characterized in that, The preset deviation value is 0.5mm; the comparison of all acquired spacing values ​​A with the preset deviation value includes: Compare all the obtained spacing values ​​A with 0.5 mm; If all spacing values ​​A are less than 0.5 mm, then the verticality of the window opening of the insulating film meets the design requirements; If any spacing value A is greater than or equal to 0.5 mm, the verticality of the window opening of the insulating film does not meet the design requirements.

3. The detection method according to claim 1, characterized in that, The two-dimensional image measuring instrument includes an optical lens and a camera transmission system; acquiring the selected window image information using the two-dimensional image measuring instrument includes: The optical lens is used to magnify and image the window; The magnified image information of the window is transmitted to the display screen using the camera transmission system.

4. The detection method according to claim 1, characterized in that, The opening is square in shape; determining the center line of the opening in the window along the width direction of the insulating film, or the line connecting the centers of two openings in the window along the width direction of the insulating film, using the image processing model, includes: Arbitrarily select line images of at least three of the openings in the window, and use the image processing model to determine the center line of the selected opening in the width direction of the insulating film.

5. The detection method according to claim 4, characterized in that, Determining the center line of the selected opening in the width direction of the insulating film using the image processing model includes: The image processing model is used to determine the center point of a pair of edge lines of the opening in the width direction of the insulating film; The image processing model is used to connect a pair of center points to form the center line.

6. The detection method according to claim 4, characterized in that, The step of using the image processing model to determine the center points of a pair of edges of the opening in the width direction of the insulating film includes: The two endpoints of the edge are selected using the image processing model to obtain the center point of the edge.

7. The detection method according to claim 1, characterized in that, The opening is circular in shape; determining the center line of the opening in the window along the width direction of the insulating film or the center line connecting the centers of two openings in the window along the width direction of the insulating film using the image processing model includes: Arbitrarily select line images of at least three openings in the window, and use the image processing model to determine the line image corresponding to the selected opening, so as to obtain the center of the circle corresponding to the opening; The image processing model is used to connect the center of one of the openings to the center of the other openings to form the center line.

8. The detection method according to claim 1, characterized in that, Determining the perpendicular line of the window opening in the width direction of the insulating film using the image processing model includes: Using the image processing model, a straight line perpendicular to the side of the insulating film in its width direction is drawn from the starting point or ending point of the center line or the line connecting the centers to form the perpendicular line.

9. The detection method according to any one of claims 1 to 8, characterized in that, Also includes: The length L of the window in the width direction of the insulating film is determined using the image processing model. Compare 2*A / L with 0.0025; If 2*A / L is less than or equal to 2*A / L, then the verticality of the window opening of the insulating film meets the design requirements; If 2*A / L is greater than 0.0025, then the verticality of the window opening of the insulating film does not meet the design requirements.

10. A battery cell, characterized in that, include: The battery cell housing has a pair of large surfaces and a pair of narrow sides arranged opposite to each other; The insulating film is an insulating film that meets the design requirements after being tested by the testing method described in any one of claims 1 to 9; the insulating film wraps around the periphery of the cell housing, and the opening of the insulating film is located on the narrow side of the cell housing; along the setting direction of the pair of narrow side surfaces, the distance from the edge of the opening to the distance corresponding to the large surface is a, and the relationship between A and a satisfies: A / a≤0.15.

Images