Method of detecting a battery cell and battery cell detection device

Abstract

The present disclosure provides a method for detecting an electric core, comprising: irradiating the electric core in a first detection position with X-rays with a first direction, and obtaining a first image, the first direction being parallel to a surface of a pole piece of the electric core, and an angle between the first direction and a second side being a first predetermined angle, the first predetermined angle being no more than 30°; irradiating the electric core in a second detection position with X-rays with a second direction, and obtaining a second image, in the second detection position, an angle between the second direction and a third side being a second predetermined angle, the second predetermined angle being no more than 30°; determining a coating condition of the electric core at a first angle according to the first image, the first angle being an angle between the first side and the second side; and determining a coating condition of the electric core at a second angle according to the second image, the second angle being an angle between the second side and the third side. The present disclosure also provides an electric core detection device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of battery cell detection, and in particular, to a method for detecting a battery cell and a battery cell detection device. BACKGROUND

[0002] After battery lamination / welding, if the coating of the electrode sheet is abnormal, it will cause lithium precipitation and other hidden dangers in the battery. Therefore, after the battery lamination / welding, the alignment and coating abnormality of the lamination are needed to be detected by X-ray.

[0003] The commonly used detection method in the industry is to use X-ray detection. By using the penetration of X-ray and the different attenuation of X-ray on different density materials, the gray value of the imaging of different density materials (electrode sheet) is different when X-ray imaging, and the gray value is used to identify the difference to automatically identify and detect the coating of the electrode sheet.

[0004] However, the phenomenon of missed judgment or misjudgment of the coating abnormality of the electrode sheet still occurs from time to time. SUMMARY

[0005] The present disclosure provides a method for detecting a battery cell and a battery cell detection device to reduce the missed detection or misjudgment of the coating abnormality when detecting the battery cell.

[0006] As a first aspect of the present disclosure, a method for detecting a battery cell is provided, comprising:

[0007] X-ray is used to irradiate the battery cell in a first detection position, and a first image is obtained, the direction of the X-ray is a first direction, the first direction is parallel to the surface of the electrode sheet of the battery cell, the battery cell includes a first side, a second side adjacent to the first side, and a third side opposite to the first side, the angle between the first direction and the second side is a first predetermined angle, and the first predetermined angle is not more than 30°;

[0008] X-ray is used to irradiate the battery cell in a second detection position, and a second image is obtained, the direction of the X-ray is a second direction, and the angle between the second direction and the third side is a second predetermined angle in the second detection position, and the second predetermined angle is not more than 30°;

[0009] The coating condition of the battery cell at a first angle is determined according to the first image, the first angle is the angle between the first side and the second side;

[0010] The coating condition of the battery cell at a second angle is determined according to the second image, the second angle is the angle between the second side and the third side.

[0011] Optionally, the first predetermined angle and the second predetermined angle are both between 10° and 20°.

[0012] Optionally, the length of the first side is greater than the length of the second side, and the first predetermined angle is smaller than the second predetermined angle.

[0013] Optionally, the method further comprises:

[0014] According to the coating condition of the battery cell at the first angle and the coating condition of the battery cell at the second angle, it is determined whether the battery cell is a good product.

[0015] Optionally, the method further comprises:

[0016] In the case that the battery cell is not a good product, according to the coating condition of the battery cell at the first angle and the coating condition of the battery cell at the second angle, the type of the battery cell is determined.

[0017] Optionally, the first direction and the second direction are the same, and between the X-ray irradiation of the battery cell at the first detection position with the first direction of the ray direction and the X-ray irradiation of the battery cell at the second detection position with the second direction of the ray direction, the method further comprises:

[0018] The battery cell is rotated with the center of the battery cell as the rotation center, so that the battery cell is transformed from the first detection position to the second detection position.

[0019] As a second aspect of the present disclosure, an electric cell detection device is provided, which comprises a control module, an X-ray device, an image generation device and an image recognition device;

[0020] The control module is configured to control the X-ray device to emit X-ray with the first direction of the ray direction to the battery cell at the first detection position, and control the image generation device to generate the first image, wherein the first direction is parallel to the surface of the pole piece of the battery cell, the battery cell comprises a first side, a second side adjacent to the first side, and a third side opposite to the first side, the angle between the first direction and the second side is a first predetermined angle, and the first predetermined angle is not more than 30°.

[0021] The control module is further configured to control the X-ray device to emit X-ray with the second direction of the ray direction to the battery cell at the second detection position, and control the image generation device to generate the second image, wherein the second direction is parallel to the surface of the pole piece of the battery cell, and the angle between the second direction and the third side is a second predetermined angle, and the second predetermined angle is not more than 30°.

[0022] The image recognition device is configured to determine the wrapping condition at a first corner of the battery cell according to the first image, and determine the wrapping condition at a second corner of the battery cell according to the second image, the first corner being the corner between the first edge and the second edge, and the second corner being the corner between the second edge and the third edge.

[0023] Optionally, the first predetermined angle and the second predetermined angle are both between 10° and 20°.

[0024] Optionally, the length of the first edge is less than the length of the second edge, and the first predetermined angle is greater than the second predetermined angle.

[0025] Optionally, the control module is further configured to determine whether the battery cell is a good product according to the wrapping condition at the first corner of the battery cell and the wrapping condition at the second corner of the battery cell.

[0026] Optionally, the control module is further configured to determine the bad type of the battery cell according to the wrapping condition at the first corner of the battery cell and the wrapping condition at the second corner of the battery cell, in the case that the battery cell is a non-good product.

[0027] Optionally, the first direction and the second direction are the same, and between the case that the battery cell detection device irradiates the battery cell at the first detection position with X-ray of the first direction, and the case that the battery cell detection device irradiates the battery cell at the second detection position with X-ray of the second direction, the battery cell detection device further comprises a battery cell operating device, and the control module is further configured to control the battery cell operating device to operate the battery cell to rotate around the center of the battery cell and switch between the first detection position and the second detection position.

[0028] When detecting the battery cell, the angle between the direction of the X-ray and the first edge A is not more than 30°, which is close to parallel to the first edge, so that the wrapping value measured at the first corner is closer to the real wrapping value of the positive plate and the negative plate of the battery cell at the first edge. Similarly, the angle between the direction of the X-ray and the second edge is not more than 30°, which is also close to parallel to the second edge, so that the wrapping value measured at the second corner is also closer to the wrapping value of the positive plate and the negative plate of the battery cell at the second edge. Therefore, the detection method provided by the present disclosure can at least reduce the phenomenon of false detection or missed detection, and improve the accuracy of battery cell detection. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1a is a flowchart of a method for detecting a battery cell in the related art;

[0030] Figure 1b is a schematic diagram of a battery cell detection device according to the present disclosure; Figure 1a is a schematic diagram of determining the wrapping condition at corner a and the wrapping condition at corner b by using the detection method shown in

[0031] Figure 2 is a flowchart of one embodiment of the method for detecting the battery cell provided by the present disclosure;

[0032] Figure 3 is a flowchart of one embodiment of the method for detecting the battery cell provided by the present disclosure;

[0033] Figure 4 is a schematic diagram of determining the coating condition at the first angle and the coating condition at the second angle by using the method provided by the present disclosure;

[0034] Figure 5 is several extreme coating conditions of CAD simulation and the coating values at the first angle and the second angle respectively DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the embodiments of the present disclosure will be described in detail below with reference to the drawings. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other as long as there is no conflict.

[0036] In the related art, the coating condition of the battery cell is detected by using the method shown in Figure 1a The detection process specifically includes:

[0037] The battery cell at the first position is irradiated by X-rays, wherein the angle between the direction of the X-rays and the first side of the battery cell is 45°, and an initial image is obtained;

[0038] The battery cell is rotated clockwise by 90°, so that the angle between the second side of the battery cell and the direction of the X-rays is 45°, and a secondary image is obtained.

[0039] The first side and the second side are adjacent. The coating condition at the angle a can be determined by identifying the initial image, and the coating condition at the angle b can be determined by identifying the secondary image. Figure 1b In the formula (1), d1 represents the coating condition at the angle a, and the coating condition at the angle a can reflect the coating condition of the pole piece of the battery cell in the height direction (i.e., the up-down direction in FIG. 1), Figure 1b In the formula (2), d2 represents the coating condition at the angle b, and the coating condition at the angle b can reflect the coating condition of the pole piece of the battery cell in the width direction (i.e., the left-right direction in FIG. 1). However, since the two detection angles are both 45°, the detection effect is the same, and the height coating abnormality and the width coating abnormality of the battery cell cannot be accurately reflected, which may cause misjudgment or missed judgment.

[0040] Therefore, as a first aspect of the present disclosure, a method for detecting a battery cell is provided, as shown in Figure 2 andFigure 3 As shown, it includes:

[0041] In step S110, the cell 100 located at the first detection position is irradiated with X-rays in the first direction and a first image is obtained. The first direction is parallel to the electrode surface of the cell 100. The cell 100 includes a first side A, a second side B adjacent to the first side A, and a third side C opposite to the first side A. The angle between the first direction and the second side B is a first predetermined angle, which does not exceed 30°.

[0042] In step S120, the cell 100 at the second detection position is irradiated with X-rays in the direction of the second direction and a second image is obtained. At the second detection position, the angle between the second direction and the third side C is a second predetermined angle, which does not exceed 30°.

[0043] In step S130, the coverage of the electrode of the cell 100 at the first corner a is determined according to the first image, where the first corner a is the angle between the first side C and the second side B;

[0044] In step S140, the coverage of the electrode of the cell 100 at the second corner b is determined according to the second image, where the second corner b is the angle between the second side B and the third side A.

[0045] In step S110, the angle between the X-ray direction and the second side B does not exceed 30°, and is nearly parallel to the second side B. Therefore, the coating value measured at the first angle is closer to the actual coating values ​​of the positive and negative electrodes of the cell 100 at the second side B. Figure 4 (The left and right coverage situation in the middle). Similarly, in step S120, the angle between the X-ray ray direction and the second side B does not exceed 30°, and is also close to parallel to the third side C. The coverage value measured at the second angle is also closer to the coverage values ​​of the positive and negative electrode plates of the cell 100 at the third side C. Figure 4 (The top and bottom covering conditions in the cell). Therefore, the detection method provided in this disclosure can at least reduce the occurrence of false detections or missed detections, and improve the accuracy of cell detection.

[0046] In this disclosure, as an optional implementation, the "coverage value measured at the first corner" can refer to the distance between the vertex of the positive electrode at the first corner and the vertex of the negative electrode at the first corner. Of course, when the corners of the positive electrode and the negative electrode substrate are rounded, the "coverage value measured at the first corner" can refer to the distance between the tangent of the X-ray to the rounded corner of the positive electrode at the first corner and the tangent of the X-ray to the rounded corner of the negative electrode at the first corner.

[0047] The "overwrap value measured at the second corner" can refer to the distance between the vertex of the positive electrode tab at the second corner and the vertex of the negative electrode tab at the second corner. Of course, when the corners of the positive electrode tab and the negative electrode tab are rounded corners, the "overwrap value measured at the second corner" can refer to the distance between the tangent of the X-ray and the rounded corner of the positive electrode tab at the second corner and the tangent of the X-ray and the rounded corner of the negative electrode tab at the second corner.

[0048] In the present disclosure, the specific values of the first predetermined angle and the second predetermined angle are not particularly limited as long as they are not more than 30°. It should be noted that the smaller the angle between the first direction and the first side, the longer the length of the overlap of the tabs is measured. In order to avoid X-ray imaging ghosting, the first predetermined angle is optionally between 10° and 20°, so that a clear first image can be obtained. Similarly, the second predetermined angle is between 10° and 20°, so that a clear second image can be obtained.

[0049] As an optional embodiment, the shape of the battery cell is rectangular. The length of the first side A is greater than the length of the second side B. In order to facilitate the distinction between the first image and the second image, the first predetermined angle can be smaller than the second predetermined angle accordingly. Optionally, the first predetermined angle is 20° and the second predetermined angle is 14°.

[0050] In the present disclosure, after obtaining the overwrap condition of the battery cell at the first corner and the overwrap condition of the battery cell at the second corner, the data can be output for other devices to determine whether the battery cell is a good product. In order to improve the detection efficiency, the step of determining whether the battery cell is a good product can be performed by the electronic device performing the current method. Accordingly, the method further comprises:

[0051] In step S150, it is determined whether the battery cell is a good product according to the overwrap condition of the battery cell at the first corner and the overwrap condition of the battery cell at the second corner.

[0052] In the present disclosure, it can be determined whether the battery cell is a good product by comparing the overwrap value at the first corner with the corresponding first qualified range and comparing the overwrap value at the second corner with the corresponding second qualified range. If the overwrap value at the first corner is not within the first qualified range, the battery cell is a defective product. If the overwrap value at the second corner is not within the second qualified range, the battery cell is also a defective product. Only when the overwrap value at the first corner is within the first qualified range and the overwrap value at the second corner is within the second qualified range, it can be determined that the battery cell is a good product.

[0053] In the present disclosure, how to determine the first qualified range and the second qualified range is not particularly limited. As an optional embodiment, the first qualified range and the second qualified range can be set by the process requirements of the battery cell.

[0054] As an optional embodiment, when the first predetermined angle is 20° and the second predetermined angle is 14°, the battery cell is determined to be a good product when the cladding value of the battery cell at the first angle is between 1.15 mm and 3.58 mm, and the cladding value of the battery cell at the second angle is between 1.17 mm and 4.46 mm.

[0055] In the present disclosure, various extreme cladding cases can be simulated by CAD, and the cladding values at the first angle and the second angle in various extreme cladding cases can be measured. Specifically, the X-ray in the first direction can be simulated by a straight line with the second side at a first predetermined angle, and the X-ray in the second direction can be simulated by a straight line with the third side at a second predetermined angle.

[0056] Figure 5 Shown in FIG. 1 are several extreme cladding cases simulated by CAD, and the cladding values at the first angle and the second angle, respectively. In the art, the standard cladding refers to the case where the centers of the positive and negative electrode tabs of the battery cell are aligned. In this case, the upper and lower cladding values are the same, and the left and right cladding values are also the same.

[0057] wherein, Figure 5 (a) in FIG. 1 is a schematic view of the angle b (the second angle) in the case of standard cladding;

[0058] Figure 5 (b) in FIG. 1 is a schematic view of the angle a (the first angle) in the case of standard cladding;

[0059] Figure 5 (c) in FIG. 1 is a schematic view of the angle b in the case where the fourth side of the positive electrode tab is aligned with the fourth side of the negative electrode tab, wherein the fourth side is the side opposite to the third side;

[0060] Figure 5 (d) in FIG. 1 is a schematic view of the angle a in the case where the first side of the positive electrode tab is aligned with the first side of the negative electrode tab;

[0061] Figure 5 (e) in FIG. 1 is a schematic view of the angle b in the case where the second side of the positive electrode tab is aligned with the second side of the negative electrode tab;

[0062] Figure 5 (f) in FIG. 1 is a schematic view of the angle b in the case where the third side of the positive electrode tab is aligned with the first side of the negative electrode tab;

[0063] Figure 5 (g) in FIG. 1 is a schematic view of the angle b in the case where the first side of the positive electrode tab is aligned with the first side of the negative electrode tab, and the fourth side of the positive electrode tab is aligned with the fourth side of the negative electrode tab;

[0064] Figure 5(h) is a schematic view at the angle b when the third edge of the positive electrode sheet is aligned with the third edge of the negative electrode sheet and the second edge of the positive electrode sheet is aligned with the second edge of the negative electrode sheet in FIG. 1;

[0065] Figure 5 (i) is a schematic view at the angle a when the first edge of the positive electrode sheet is aligned with the first edge of the negative electrode sheet and the second edge of the positive electrode sheet is aligned with the second edge of the negative electrode sheet in FIG. 1;

[0066] Figure 5 (j) is a schematic view at the angle a when the first edge of the positive electrode sheet is aligned with the first edge of the negative electrode sheet and the fourth edge of the positive electrode sheet is aligned with the fourth edge of the negative electrode sheet in FIG. 1;

[0067] Figure 5 (k) is a schematic view at the angle b when the third edge of the negative electrode sheet covers the third edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0068] Figure 5 (l) is a schematic view at the angle a when the first edge of the negative electrode sheet covers the first edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0069] Figure 5 (m) is a schematic view at the angle a when the second edge of the negative electrode sheet covers the second edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0070] Figure 5 (n) is a schematic view at the angle b when the third edge of the negative electrode sheet covers the third edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0071] Figure 5 (o) is a schematic view at the angle a when the fourth edge of the negative electrode sheet covers the fourth edge of the positive electrode sheet by 0.5 mm and the first edge of the negative electrode sheet covers the first edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0072] Figure 5 (p) is a schematic view at the angle b when the third edge of the negative electrode sheet covers the third edge of the positive electrode sheet by 0.5 mm and the second edge of the negative electrode sheet covers the second edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0073] Figure 5 (q) is a schematic view at the angle a when the first edge of the negative electrode sheet covers the first edge of the positive electrode sheet by 0.5 mm and the second edge of the negative electrode sheet covers the second edge of the positive electrode sheet by 0.5 mm in FIG. 1;

[0074] Figure 5 (r) is a schematic view at the angle b when the first edge of the negative electrode sheet covers the first edge of the positive electrode sheet by 0.5 mm and the second edge of the negative electrode sheet covers the second edge of the positive electrode sheet by 0.5 mm in FIG. 1.

[0075] Table 1 shows ​Simulation values of the covering of the angle a and the angle b in each of (a) to (r) in Table 1, and X-ray measured values.

[0076] Table 1

[0077]

[0078]

[0079] In the present disclosure, in the case that the battery cell is a non-good product, the bad type of the battery cell is determined according to the covering of the battery cell at a first angle and the covering of the battery cell at a second angle.

[0080] For example, when the covering value at the first angle is identified as 2.97 and the covering value at the first angle is identified as 4.93, it indicates that the bad condition at this time is that the fourth edge of the positive electrode plate is aligned with the fourth edge of the negative electrode plate.

[0081] In the present disclosure, steps S110 and S120 can be realized by changing the direction of the X-ray, or alternatively, to facilitate operation, the state of the battery cell can be changed to realize steps S110 and S120, that is, the first direction and the second direction are the same, and correspondingly, between the battery cell in the first detection position irradiated by the X-ray with the first direction and the battery cell in the second detection position irradiated by the X-ray with the second direction, the method further comprises:

[0082] Rotating the battery cell with the center of the battery cell as the rotation center, so that the battery cell is transformed from the first detection position to the second detection position.

[0083] As a second aspect of the present disclosure, a battery cell detection device is provided, which comprises a control module, an X-ray device 200, an image generation device 300 and an image recognition device.

[0084] The control module is configured to control the X-ray device 200 to emit X-ray with the first direction to the battery cell 100 in the first detection position, and control the image generation device 300 to generate the first image, wherein the first direction is parallel to the surface of the electrode plate of the battery cell, the battery cell comprises a first edge, a second edge adjacent to the first edge, and a third edge opposite to the first edge, the angle between the first direction and the second edge is a first predetermined angle, and the first predetermined angle is not more than 30°.

[0085] The control module is further configured to control the X-ray device 200 to emit X-rays in a second direction parallel to the surface of the pole piece of the battery cell 100 in the second detection position, and control the image generation device 300 to generate a second image, wherein the second direction forms a second predetermined angle with the third side, and the second predetermined angle is not more than 30°.

[0086] The image recognition device is configured to determine the coating condition of the battery cell at a first angle between the first side and the second side according to the first image, and determine the coating condition of the battery cell at a second angle between the second side and the third side according to the second image.

[0087] The battery cell detection device provided by the present disclosure is configured to detect the coating condition of the battery cell according to the method for detecting the battery cell provided by the present disclosure. The principle and advantages of the above method have been described in detail above, and will not be described here again.

[0088] As described above, the first predetermined angle and the second predetermined angle are both between 10° and 20°.

[0089] Optionally, the length of the first side is less than the length of the second side, and the first predetermined angle is greater than the second predetermined angle.

[0090] In the present disclosure, the specific values of the first predetermined angle and the second predetermined angle are not specially limited, as long as they are not more than 30°. It should be noted that the smaller the angle between the first direction and the first side, the longer the measured pole piece overlap length. In order to avoid X-ray imaging ghosting, the first predetermined angle is optionally between 10° and 20°, so that a clear first image can be obtained. Similarly, the second predetermined angle is between 10° and 20°, so that a clear second image can be obtained.

[0091] As an optional implementation, the shape of the battery cell is rectangular. The length of the first side A is greater than the length of the second side B. In order to facilitate the distinction between the first image and the second image, the first predetermined angle can be less than the second predetermined angle accordingly. Optionally, the first predetermined angle is 20°, and the second predetermined angle is 14°.

[0092] Optionally, the control module is further configured to determine whether the battery cell is a good product according to the coating condition of the battery cell at the first angle and the coating condition of the battery cell at the second angle.

[0093] Optionally, the control module is further configured to determine the type of defect of the battery cell according to the coating condition of the battery cell at the first angle and the coating condition of the battery cell at the second angle in the case that the battery cell is a non-good product.

[0094] Optionally, the first direction and the second direction are the same, and between the X-ray irradiation of the battery cell at the first detection position in the first direction and the X-ray irradiation of the battery cell at the second detection position in the second direction, the battery cell detection device further comprises a battery cell operating device, and the control module is further configured to control the battery cell operating device to operate the battery cell to rotate around the center of the battery cell and switch between the first detection position and the second detection position.

[0095] The above merely describes exemplary embodiments of the present disclosure, and is not intended to limit the protection scope of the present disclosure. Generally, various embodiments of the present disclosure can be implemented in hardware or special-purpose circuitry, software, logic, or any combination thereof. For example, some aspects can be implemented in hardware, while other aspects can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device, although the present disclosure is not limited thereto.

[0096] Embodiments of the present disclosure can be implemented by a data processor of a mobile device executing computer program instructions, for example, in a processor entity, or by hardware, or by a combination of software and hardware. The computer program instructions can be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages.

[0097] Any block diagrams of logical flows of the present disclosure can represent program steps, or can represent interconnected logic circuits, modules, and functions, or can represent a combination of program steps and logic circuits, modules, and functions. The computer program can be stored on a memory. The memory can be of any suitable type and can be implemented using any suitable data storage technology, such as, but not limited to, read-only memory (ROM), random access memory (RAM), optical storage devices, and systems (digital versatile disc DVD or CD disc), and the like. The computer readable medium can include a non-transitory storage medium. The data processor can be of any suitable type and can be implemented using any suitable technology, such as, but not limited to, a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), and a processor based on a multi-core processor architecture.

[0098] A detailed description of exemplary embodiments of the present disclosure has been provided above with reference to the accompanying drawings. However, various modifications and alterations of the above embodiments will be apparent to those skilled in the art without departing from the scope of the present disclosure, which is defined by the appended claims. Thus, the proper scope of the present disclosure is to be determined by the appended claims.

Claims

1. A method for detecting an electric core, comprising: irradiating the electric core in a first detection position with X-rays having a first direction, and obtaining a first image, the first direction being parallel to a surface of a pole piece of the electric core, the electric core comprising a first side, a second side adjacent to the first side, and a third side opposite to the first side, an angle between the first direction and the second side being a first predetermined angle, the first predetermined angle being no more than 30°; irradiating the electric core in a second detection position with X-rays having a second direction, and obtaining a second image, in the second detection position, an angle between the second direction and the third side being a second predetermined angle, the second predetermined angle being no more than 30°; determining, according to the first image, a wrapping condition of the pole piece of the electric core at a first angle, the first angle being an angle between the first side and the second side, the wrapping condition at the first angle reflecting a wrapping condition of the pole piece of the electric core in a height direction; determining, according to the second image, a wrapping condition of the pole piece of the electric core at a second angle, the second angle being an angle between the second side and the third side, the wrapping condition at the second angle reflecting a wrapping condition of the pole piece of the electric core in a width direction.

2. The method of claim 1, wherein, The first predetermined angle and the second predetermined angle are both between 10° and 20°.

3. The method of claim 2, wherein, The length of the first side is greater than the length of the second side, and the first predetermined angle is less than the second predetermined angle.

4. The method according to any one of claims 1 to 3, wherein, The method further comprises: determining, according to the wrapping condition of the pole piece of the electric core at the first angle and the wrapping condition of the pole piece of the electric core at the second angle, whether the electric core is a good product.

5. The method of claim 4, wherein, The method further comprises: in a case where the electric core is not a good product, determining a bad type of the electric core according to the wrapping condition of the electric core at the first angle and the wrapping condition of the electric core at the second angle.

6. The method of any one of claims 1 to 3, wherein, The first direction and the second direction are the same, and between the irradiating the electric core in the first detection position with X-rays having the first direction and the irradiating the electric core in the second detection position with X-rays having the second direction, the method further comprises: rotating the electric core with a center of the electric core as a rotation center, so that the electric core is transformed from the first detection position to the second detection position. 7.An electric core detection device, comprising a control module, an X-ray device, an image generation device, and an image recognition device; The control module is configured to control the X-ray device to emit X-rays with a first direction of emission to the battery cell in the first detection position, and control the image generation device to generate a first image, wherein The first direction is parallel to a surface of a pole piece of the electric core, the electric core comprising a first side, a second side adjacent to the first side, and a third side opposite to the first side, an angle between the first direction and the second side being a first predetermined angle, the first predetermined angle being no more than 30°; The control module is further configured to control the X-ray device to emit X-rays having a second direction to an electric core in a second detection position, and control the image generation device to generate a second image, wherein the second direction is parallel to a surface of a pole piece of the electric core, and an angle between the second direction and the third side is a second predetermined angle, the second predetermined angle being no more than 30°. The image recognition device is configured to determine the wrapping condition at a first corner of the battery cell according to the first image and determine the wrapping condition at a second corner of the battery cell according to the second image, the first corner being an angle between the first edge and the second edge, and the second corner being an angle between the second edge and the third edge. The wrapping condition at the first corner reflects the wrapping condition of the pole piece of the battery cell in the height direction, and the wrapping condition at the second corner reflects the wrapping condition of the pole piece of the battery cell in the width direction.

8. The battery cell testing apparatus of claim 7, wherein, The first predetermined angle and the second predetermined angle are both between 10° and 20°.

9. The battery cell testing apparatus of claim 8, wherein, The length of the first edge is less than the length of the second edge, and the first predetermined angle is greater than the second predetermined angle.

10. The battery cell testing apparatus according to any one of claims 7 to 9, wherein The control module is further configured to determine whether the battery cell is a good product according to the wrapping condition of the pole piece of the battery cell at the first corner and the wrapping condition of the pole piece of the battery cell at the second corner.

11. The battery cell testing apparatus of claim 10, wherein, The control module is further configured to determine the bad type of the battery cell according to the wrapping condition of the pole piece of the battery cell at the first corner and the wrapping condition of the pole piece of the battery cell at the second corner when the battery cell is a non-good product.

12. The battery cell testing apparatus according to any one of claims 7 to 9, wherein The first direction and the second direction are the same, and between the battery cell in the first detection position irradiated by the X-ray with the first direction of the ray and the battery cell in the second detection position irradiated by the X-ray with the second direction of the ray, the battery cell detection device further comprises a battery cell operating device, and the control module is further configured to control the battery cell operating device to operate the battery cell to rotate around the center of the battery cell and switch between the first detection position and the second detection position.

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