Laminated cell detection method and detection system

Abstract

The invention discloses a detection method and a detection system for a laminated cell. The detection method comprises the following steps: a coordinate system calibration step: calibrating a plane coordinate system and a polar coordinate system in a plane perpendicular to a first direction by at least one group of ray emitting device and ray receiving device; a position calculation step: capturing a characteristic angular point of a pole piece to be measured in the plurality of pole pieces by each group of ray emitting device and ray receiving device, and positioning a coordinate of a central point of the pole piece to be measured in a plane coordinate system and a polar axis angle of the central point in a polar coordinate system according to the characteristic angular point, a radioactive ray beam between each group of ray emitting device and ray receiving device passes through two sides of the corresponding characteristic angular point; and an offset determination step: calculating the offset of the to-be-measured pole piece according to the coordinate of the central point of the to-be-measured pole piece and the polar axis angle, and determining whether the offset meets the offset requirement or not. The above technical scheme at least can effectively detect the positive and negative electrode dislocation of the laminated cell.

Description

Technical Field

[0001] The present invention relates to the technical field of battery detection, and more specifically, to a detection method and a detection system for a laminated battery cell. Background Art

[0002] The misalignment distance between the positive and negative electrodes is the core control point of the battery manufacturing process, which is related to the safety performance of the battery product. The misalignment distance between the positive and negative electrodes refers to the distance in length or width between the positive electrode sheet (also called the cathode sheet) and the negative electrode sheet (also called the anode sheet) in the battery process, where the negative electrode exceeds the positive electrode. This design is mainly to ensure that during the charging and discharging process, the lithium ions are embedded and carried by the corresponding negative electrode graphite as a container to avoid excessive precipitation of lithium ions, forming branched crystals, and causing short circuits in the battery cell, resulting in safety problems such as low voltage, overheating or fire.

[0003] At present, the main method for detecting the distance between the positive and negative poles is to irradiate the battery cell with X-rays, receive the information through a receiver, and use the difference in the absorption rate of X-rays by materials of different densities of the positive and negative poles to convert the signal on the receiver into a positive and negative pole misalignment image through an algorithm. For wound battery cells, because there is a gradual difference in the thickness of the positive and negative poles at the corners in the width direction of the battery cell, X-rays can form a clear and effective image through frontal irradiation. However, for stacked battery cells, there is no area with a gradual change in the thickness of the positive and negative poles at the corners, and it is impossible to identify the misalignment of the positive and negative poles by frontal irradiation from a mechanism level. Therefore, a method that can effectively detect the misalignment of the positive and negative poles of stacked battery cells is needed. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present application provides a detection method and a detection system for laminated battery cells, which can at least effectively detect the misalignment of the positive and negative poles of the laminated battery cells.

[0005] According to an embodiment of the present application, a detection method for a stacked battery cell is provided, wherein the stacked battery cell includes a plurality of pole pieces stacked along a first direction, and the detection method includes: a coordinate system calibration step: at least one group of ray emitting devices and ray receiving devices are used to calibrate a plane coordinate system and a polar coordinate system in a plane perpendicular to the first direction; a position calculation step: each group of ray emitting devices and ray receiving devices captures characteristic corner points of a pole piece to be tested among a plurality of pole pieces, and locates the coordinates of a center point of the pole piece to be tested in the plane coordinate system and the polar axis angle in the polar coordinate system according to the characteristic corner points, wherein a radiation beam between each group of ray emitting devices and ray receiving devices passes through two sides of the corresponding characteristic corner point; an offset determination step: the offset of the pole piece to be tested is calculated according to the coordinates of the center point of the pole piece to be tested and the polar axis angle, and it is determined whether the offset meets the offset requirement.

[0006] In some embodiments, the position calculation step includes: each group of ray emitting devices and ray receiving devices respectively captures the first characteristic corner point of a first pole piece to be measured among multiple pole pieces, and locates the first coordinate of the center point of the first pole piece to be measured in the plane coordinate system and the first polar axis angle in the polar coordinate system according to the first characteristic corner point; each group of ray emitting devices and ray receiving devices captures the second characteristic corner point of a second pole piece to be measured among multiple pole pieces, and locates the second coordinate of the center point of the second pole piece to be measured in the plane coordinate system and the second polar axis angle in the polar coordinate system according to the second characteristic corner point, wherein the first pole piece to be measured is adjacent to the second pole piece to be measured along a first direction; wherein the offset requirement is determined according to the distance requirement between the first characteristic corner point of the first pole piece to be measured and the corresponding second characteristic corner point of the second pole piece to be measured in the plane coordinate system.

[0007] In some embodiments, at least one set of ray emitting devices and ray receiving devices includes four sets of ray emitting devices and ray receiving devices, which are respectively used to capture four characteristic corner points of the pole piece to be tested, wherein the four characteristic corner points are respectively located in four quadrants of the plane coordinate system.

[0008] In some embodiments, one of the four quadrants has two characteristic corner points, and a corresponding set of ray emitting devices and ray receiving devices for capturing the two characteristic corner points are arranged so that their radiation beams pass through the edges forming the two characteristic corner points.

[0009] In some embodiments, the radiation beam arranged in each group of radiation emitting devices and radiation receiving devices is perpendicular to the radiation beam arranged in an adjacent group of radiation emitting devices and radiation receiving devices.

[0010] According to an embodiment of the present application, a detection system for a stacked battery cell is also provided, wherein the stacked battery cell includes a plurality of pole pieces stacked along a first direction, and the detection system includes: at least one group of ray emitting devices and ray receiving devices, used to calibrate a plane coordinate system and a polar coordinate system in a plane perpendicular to the first direction, and used to capture characteristic corner points of a pole piece to be tested among the plurality of pole pieces, wherein the radiation beam between each group of ray emitting devices and ray receiving devices passes through two sides of the corresponding characteristic corner point; a position calculation unit: used to locate the coordinates of the center point of the pole piece to be tested in the plane coordinate system and the polar axis angle in the polar coordinate system according to the characteristic corner point; an offset determination unit: used to calculate the offset of the pole piece to be tested according to the coordinates of the center point of the pole piece to be tested and the polar axis angle, and determine whether the offset meets the offset requirement.

[0011] In some embodiments, each group of ray emitting devices and ray receiving devices respectively captures a first characteristic corner point of a first pole piece to be measured among multiple pole pieces, and locates a first coordinate of a center point of the first pole piece to be measured in a plane coordinate system and a first polar axis angle in a polar coordinate system based on the first characteristic corner point; each group of ray emitting devices and ray receiving devices captures a second characteristic corner point of a second pole piece to be measured among multiple pole pieces, and locates a second coordinate of a center point of the second pole piece to be measured in a plane coordinate system and a second polar axis angle in a polar coordinate system based on the second characteristic corner point, wherein the first pole piece to be measured and the second pole piece to be measured are adjacent to each other along a first direction; wherein the position calculation unit determines the offset requirement based on the distance requirement between the first characteristic corner point of the first pole piece to be measured and the corresponding second characteristic corner point of the second pole piece to be measured in the plane coordinate system.

[0012] In some embodiments, at least one set of ray emitting devices and ray receiving devices includes four sets of ray emitting devices and ray receiving devices, which are respectively used to capture four characteristic corner points of the pole piece to be tested, wherein the four characteristic corner points are respectively located in four quadrants of the plane coordinate system.

[0013] In some embodiments, one of the four quadrants has two characteristic corner points, and a corresponding set of ray emitting devices and ray receiving devices for capturing the two characteristic corner points are arranged so that their radiation beams pass through the edges forming the two characteristic corner points.

[0014] In some embodiments, the number of the at least one group of radiation emitting devices and radiation receiving devices is from one group to four groups.

[0015] The above technical scheme of the present invention captures the characteristic corner points of the pole piece through irradiation by a ray emitting device and a ray receiving device, and then uses the coordinate pole piece offset obtained by calculation of the characteristic corner points to determine whether the positive and negative pole misalignment distance requirements are met. Based on the conditions of existing equipment and hardware, more accurate measurement of the misalignment distance of the positive and negative pole pieces of the battery cell is achieved, which can reduce or eliminate the situation of missing poles. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of an existing method for detecting misalignment of stacked batteries.

[0018] Figure 2 It is a flow chart of a method for detecting a laminated battery cell according to an embodiment of the present application.

[0019] Figure 3-Figure 4 It is a structural schematic diagram of different stages of testing a laminated battery cell according to the testing method of the present invention.

[0020] Figure 5A and Figure 5B Schematic diagram of different feature corner points captured by the detection method of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0022] like Figure 1 As shown, for the laminated battery cells 10, 10' including the stacked positive pole piece 12 and the negative pole piece 14, the common method for detecting the misalignment of the positive and negative poles in the industry is to irradiate the positive pole piece 12 and the negative pole piece 14 at an oblique angle (the angle corresponding to the distance difference D01) by X-ray, measure the projection distance difference D01 between the positive pole piece 12 and the negative pole piece 14 in the oblique direction, and calculate a certain specification according to the misalignment distance of the positive and negative poles for control, but this method has significant omissions. Specifically, Figure 1 As shown, the relative position size control of the positive and negative electrodes of the stacked battery cell requires a fixed distance difference D01 between the positive electrode piece 12 and the negative electrode piece 14. For the current stacked X-ray detection technology, the measured distance difference D01 is the projection of the misalignment distance of the positive and negative electrodes in the angular direction. The misalignment distance of the stacked battery cell 10' at position 22 does not meet the requirements, but the measured distance difference D01 does meet the requirements. Therefore, this projection measurement method determines in principle that there will be some omissions.

[0023] An embodiment of the present application provides a method for detecting a laminated battery cell. Figure 2 It is a flow chart of a method for detecting a laminated battery cell according to an embodiment of the present application. Figure 3-Figure 4 1 is a schematic diagram of the structure at different stages of testing a laminated battery cell according to the testing method of the present invention. Figure 2 and Figure 3As shown, the detection method 200 includes a coordinate system calibration step S202: at least one group of ray (such as X-ray) emitting devices and ray (such as X-ray) receiving devices are used to calibrate the plane coordinate system XY and the polar coordinate system U in the plane perpendicular to the first direction. In this embodiment, four groups of ray emitting devices 140a and ray receiving devices 150a, ray emitting devices 140b and ray receiving devices 150b, ray emitting devices 140c and ray receiving devices 150c, and ray emitting devices 140d and ray receiving devices 150d are shown as examples to calibrate and calibrate the physical space position and establish the plane coordinate system XY and the polar coordinate system U within the detection range. The plane coordinate system XY is perpendicular to the stacking direction of the pole pieces in the battery cell. The ray emitting devices 140a, 140b, 140c, and 140d are used to emit radiation beams 145 (such as X-rays), and the radiation beams 145 are received by the ray receiving devices 150a, 150b, 150c, and 150d.

[0024] Combination Figure 2 and Figure 4 As shown, the detection method 200 also includes a position calculation step S204: each group of ray emitting devices 140a and ray receiving devices 150a, ray emitting devices 140b and ray receiving devices 150b, ray emitting devices 140c and ray receiving devices 150c, and ray emitting devices 140d and ray receiving devices 150d captures the characteristic corner points of the first pole piece 110 to be tested. In this embodiment, the first pole piece 110 and the second pole piece 120 are shown, and the first pole piece 110 is stacked on the second pole piece 120. In this embodiment, the first pole piece 110 is a positive pole piece, and the second pole piece 120 is a negative pole piece. C1, C2, C3, and C4 are the four corner positions of the battery cell. Reference Figure 5A , showing four characteristic corner points P1, P21, P31, P4 that can be grasped, and the four characteristic corner points P1, P21, P31, P4 are respectively located in the four quadrants of the plane coordinate system XY. Figure 5BAs shown, four additional characteristic corner points P1, P22, P32, and P4 that can be captured are shown, and the four characteristic corner points P1, P22, P32, and P4 are respectively located in four quadrants of the plane coordinate system XY. The radiation beam 145 between each group of ray emitting device 140a and ray receiving device 150a, ray emitting device 140b and ray receiving device 150b, ray emitting device 140c and ray receiving device 150c, and ray emitting device 140d and ray receiving device 150d can pass through each edge (including the end points of the edge) of the corresponding characteristic corner points P1, P21, P22, P31, P32, and P4. In the four quadrants of the plane coordinate system XY, the characteristic corner points P21, P22, P61, and P62 are located in the same quadrant, and a corresponding set of ray emitting devices 140b and ray receiving devices 150b for capturing the characteristic corner points P21, P22, P61, and P62 can be arranged so that their radiation beams 145 pass through the edges that constitute the characteristic corner points P21, P22, P61, and P62. Similarly, the characteristic corner points P31, P32, P71, and P72 are located in the same quadrant, and a corresponding set of ray emitting devices 140c and ray receiving devices 150c for capturing the characteristic corner points P31, P32, P71, and P72 can be arranged so that their radiation beams 145 pass through the edges that constitute the characteristic corner points P31, P32, P71, and P72.

[0025] Then, refer to Figure 4 and Figure 5A As shown, taking the capture of four characteristic corner points P1, P21, P31, and P4 as an example, the coordinates (S, T) of the center point O1 of the first pole piece 110 in the plane coordinate system XY and the polar axis angle U1 in the polar coordinate system U are located according to the captured four characteristic corner points P1, P21, P31, and P4.

[0026] Then, the offset determination step S206 may be performed to calculate the offset of the first pole piece 110 according to the coordinates (S, T) of the center point O1 of the first pole piece 110 and the polar angle U1, and determine whether the offset meets the offset requirement. In this embodiment, the offset of the center point O1 along the X axis in the plane coordinate system XY is S, and the offset along the Y axis is T.

[0027] The above-mentioned detection method 200 of the present invention redefines a new measurement logic, captures the characteristic corner points of the pole piece through irradiation by a group of ray emitting devices and ray receiving devices, and then uses the coordinate pole piece offset obtained by calculating the characteristic corner points to determine whether it meets the positive and negative pole misalignment distance requirements. Based on the conditions of existing equipment and hardware, it realizes a more accurate measurement of the positive and negative pole misalignment distance of the battery cell, which can reduce or eliminate the situation of equipment missing.

[0028] In some embodiments, specifically in the position calculation step S204, after each group of ray emitting devices 140a and ray receiving devices 150a, ray emitting devices 140b and ray receiving devices 150b, ray emitting devices 140c and ray receiving devices 150c, and ray emitting devices 140d and ray receiving devices 150d respectively capture the characteristic corner points P1, P21, P31, and P4 of the first pole piece 110 to locate the coordinates and polar axis angles of the center point of the first pole piece 110 in the plane coordinate system, other characteristic corner points P1, P22, P32, and P4 can be captured to calculate the offset.

[0029] In some embodiments, after capturing the characteristic corner points of the first pole piece 112, the characteristic corner points of the second pole piece 120 of the next layer can be captured. The corresponding characteristic corner points P5, P61, P71, and P8 of the second pole piece 120 are captured by each group of ray emitting devices 140a and ray receiving devices 150a, ray emitting devices 140b and ray receiving devices 150b, ray emitting devices 140c and ray receiving devices 150c, and ray emitting devices 140d and ray receiving devices 150d, and similarly, the coordinates of the center point of the second pole piece 120 to be measured in the plane coordinate system XY and the polar axis angle in the polar coordinate system U are located according to the second characteristic corner points P5, P61, P71, and P8 to determine the offset of the second pole piece 120. In some embodiments, the characteristic corner points P5, P62, P72, and P8 of the second pole piece 120 can also be continuously captured to calculate the offset. As described above, the existing ray emitting device and ray receiving device can be used to capture the characteristic corner points corresponding to the first pole piece and the second pole piece of each layer in a side irradiation manner.

[0030] In some embodiments, in the offset determination step S206, the offset requirement can be determined according to the distance requirements between the characteristic corner points P1, P21, P22, P31, P32, P4 of the first pole piece 110 and the corresponding characteristic corner points P1, P21, P22, P31, P32, P4 of the second pole piece 120 in the plane coordinate system XY. The following Table 1 is the distance requirements between multiple characteristic corner points in an embodiment. In this embodiment, the width of the first pole piece 110 in the X-axis direction is 96.1 mm, and the length in the Y-axis direction is 503 mm.

[0031] Table 1

[0032]

[0033] According to the coordinates and polar axis angles of the center points of the first pole piece 110 and the second pole piece 120 obtained in step S204, the relative offsets of the first pole piece 110 and the second pole piece 120 relative to the origin of the plane coordinate system XY on the X-axis, Y-axis and polar axis U can be calculated, so that the corresponding misalignment distances of the first pole piece 110 and the second pole piece 120 can be calculated by simple tolerance chain conversion. At step S206, the control requirements of S, T, and U1 of the first pole piece and the second pole piece can be inferred from the requirements of the positive and negative pole misalignment distances of the actual product risk demand control (such as AC1 to AC12 in Table 1), and it can be determined whether the first pole piece and the second pole piece tested meet the requirements based on the requirements.

[0034] In addition, if Figure 4 As shown, in this embodiment, the first pole piece 110 and the second pole piece 120 are respectively provided with a first pole ear (positive pole ear) and a second pole ear (negative pole ear) on opposite sides along the Y axis. An insulating layer 129 is coated between the first pole ear and the active material layer of the first pole piece 110, and the characteristic corners P1 and P4 of the first pole piece 110 can be covered by the insulating layer 129. In this embodiment, the width of the insulating layer 129 in the length direction of the battery cell is 3mm. In this embodiment where some characteristic corners are covered by the insulating layer 129, the first pole piece 110 can also be detected by the above method 200.

[0035] In this embodiment, the radiation beam arranged in each group of radiation emitting devices and radiation receiving devices is perpendicular to the radiation beam arranged in the adjacent group of radiation emitting devices and radiation receiving devices.

[0036] According to an embodiment of the present invention, a detection system for laminated battery cells is also provided, and the detection system may include at least one group of ray emitting devices and ray receiving devices, such as the above-mentioned ray emitting device 140a and ray receiving device 150a, ray emitting device 140b and ray receiving device 150b, ray emitting device 140c and ray receiving device 150c, ray emitting device 140d and ray receiving device 150d. At least one group of ray emitting devices and ray receiving devices is used to calibrate the plane coordinate system and polar coordinate system in the plane perpendicular to the first direction, and is used to capture the characteristic corner points of the pole piece to be tested in multiple pole pieces, such as the above-mentioned characteristic corner points P1, P21, P22, P31, P32, P4, P5, P61, P62, P71, P72, P8. The radiation beam between each group of ray emitting devices and ray receiving devices passes through the edge of the corresponding characteristic corner point.

[0037] The detection system may further include a position calculation unit for locating the coordinates of the center point of the pole piece to be tested in the plane coordinate system and the polar axis angle in the polar coordinate system according to the characteristic corner point. The detection system may further include an offset determination unit for calculating the offset of the pole piece to be tested according to the coordinates of the center point of the pole piece to be tested and the polar axis angle, and determining whether the offset meets the offset requirement.

[0038] In some embodiments, each group of ray emitting devices and ray receiving devices respectively captures a first characteristic corner point of a first pole piece to be measured among multiple pole pieces, and locates a first coordinate of a center point of the first pole piece to be measured in a plane coordinate system and a first polar axis angle in a polar coordinate system based on the first characteristic corner point; each group of ray emitting devices and ray receiving devices captures a second characteristic corner point of a second pole piece to be measured among multiple pole pieces, and locates a second coordinate of a center point of the second pole piece to be measured in a plane coordinate system and a second polar axis angle in a polar coordinate system based on the second characteristic corner point, wherein the first pole piece to be measured and the second pole piece to be measured are adjacent to each other along a first direction; wherein the position calculation unit determines the offset requirement based on the distance requirement between the first characteristic corner point of the first pole piece to be measured and the corresponding second characteristic corner point of the second pole piece to be measured in the plane coordinate system.

[0039] To summarize, the embodiments of the present invention provide a detection method and a detection system that redefine a new measurement logic. The characteristic corner points of the pole piece are captured by irradiating a group of ray emitting devices and ray receiving devices. The coordinate pole piece offset obtained by calculating the characteristic corner points is then used to determine whether the positive and negative pole misalignment distance requirements are met. Based on the conditions of existing equipment and hardware, more accurate measurement of the positive and negative pole misalignment distance of the battery cell is achieved, which can reduce or eliminate equipment omissions.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting a laminated battery cell, characterized in that: The laminated battery core includes a plurality of pole pieces stacked along a first direction, and the detection method includes: A coordinate system calibration step: calibrating a plane coordinate system and a polar coordinate system in a plane perpendicular to the first direction by at least one set of ray emitting devices and ray receiving devices; Position calculation step: each set of ray emitting devices and ray receiving devices captures the characteristic corner points of the pole piece to be measured among the multiple pole pieces, and locates the coordinates of the center point of the pole piece to be measured in the plane coordinate system and the polar axis angle in the polar coordinate system according to the characteristic corner points, wherein the radiation beam between each set of ray emitting devices and ray receiving devices passes through two sides of the corresponding characteristic corner points; Offset determination step: calculating the offset of the pole piece to be tested according to the coordinates of the center point of the pole piece to be tested and the polar axis angle, and determining whether the offset meets the offset requirement.

2. The method for detecting laminated battery cells according to claim 1, characterized in that: The position calculation step comprises: Each group of ray emitting devices and ray receiving devices respectively captures a first characteristic corner point of a first pole piece to be tested in the pole pieces to be tested, and locates a first coordinate of a center point of the first pole piece to be tested in the plane coordinate system and a first polar axis angle in the polar coordinate system according to the first characteristic corner point; Each group of ray emitting devices and ray receiving devices captures a second characteristic corner point of a second pole piece to be tested in the pole piece to be tested, and locates a second coordinate of a center point of the second pole piece to be tested in the plane coordinate system and a second polar axis angle in the polar coordinate system according to the second characteristic corner point, wherein the first pole piece to be tested is adjacent to the second pole piece to be tested along the first direction; The offset requirement is determined according to a distance requirement between the first characteristic corner point of the first pole piece to be measured and the corresponding second characteristic corner point of the second pole piece to be measured in the plane coordinate system.

3. The method for detecting laminated battery cells according to claim 1, characterized in that: The at least one group of ray emitting devices and ray receiving devices includes four groups of ray emitting devices and ray receiving devices, which are respectively used to capture four characteristic corner points of the pole piece to be measured, wherein the four characteristic corner points are respectively located in four quadrants of the plane coordinate system.

4. The method for detecting laminated battery cells according to claim 3, characterized in that: There are two characteristic corner points in one of the four quadrants, and a corresponding set of ray emitting devices and ray receiving devices for capturing the two characteristic corner points are arranged so that their radiation beams pass through the edges forming the two characteristic corner points.

5. The method for detecting laminated battery cells according to claim 1, characterized in that: The radiation beam arranged in each group of radiation emitting devices and radiation receiving devices is perpendicular to the radiation beam arranged in an adjacent group of radiation emitting devices and radiation receiving devices.

6. A detection system for laminated battery cells, characterized in that: The laminated battery core includes a plurality of pole pieces stacked along a first direction, and the detection system includes: At least one set of ray emitting devices and ray receiving devices, used to calibrate a plane coordinate system and a polar coordinate system in a plane perpendicular to the first direction, and used to capture characteristic corner points of the pole pieces to be tested among the plurality of pole pieces, wherein the radiation beam between each set of ray emitting devices and ray receiving devices passes through two sides of the corresponding characteristic corner points; Position calculation unit: used for locating the coordinates of the center point of the pole piece to be measured in the plane coordinate system and the polar axis angle in the polar coordinate system according to the characteristic corner point; An offset determination unit is used to calculate the offset of the pole piece to be tested according to the coordinates of the center point of the pole piece to be tested and the polar axis angle, and to determine whether the offset meets the offset requirement.

7. The detection system for laminated battery cells according to claim 6, characterized in that: Each group of ray emitting devices and ray receiving devices respectively captures a first characteristic corner point of a first pole piece to be measured among the multiple pole pieces, and locates a first coordinate of a center point of the first pole piece to be measured in the plane coordinate system and a first polar axis angle in the polar coordinate system according to the first characteristic corner point; Each group of ray emitting devices and ray receiving devices captures a second characteristic corner point of a second pole piece to be measured among the multiple pole pieces, and locates a second coordinate of a center point of the second pole piece to be measured in the plane coordinate system and a second polar axis angle in the polar coordinate system according to the second characteristic corner point, wherein the first pole piece to be measured is adjacent to the second pole piece to be measured along the first direction; The position calculation unit determines the offset requirement according to a distance requirement between the first characteristic corner point of the first pole piece to be measured and the corresponding second characteristic corner point of the second pole piece to be measured in the plane coordinate system.

8. The detection system for laminated battery cells according to claim 6, characterized in that: The at least one group of ray emitting devices and ray receiving devices includes four groups of ray emitting devices and ray receiving devices, which are respectively used to capture four characteristic corner points of the pole piece to be measured, wherein the four characteristic corner points are respectively located in four quadrants of the plane coordinate system.

9. The detection system for laminated battery cells according to claim 8, characterized in that: There are two characteristic corner points in one of the four quadrants, and a corresponding set of ray emitting devices and ray receiving devices for capturing the two characteristic corner points are arranged so that their radiation beams pass through the edges forming the two characteristic corner points.

10. The detection system for laminated battery cells according to claim 6, characterized in that: The number of the at least one group of ray emitting devices and ray receiving devices is one to four groups.

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