Battery winding method, battery winding system, battery, and electric device

Abstract

A battery winding method, a battery winding system, a battery, and an electric device. The battery winding method includes a winding step; a photographing step in which an image of a current winding layer is photographed by a camera assembly; a position data acquisition step in which position data of a first point and a second point are acquired according to the image of the current winding layer, the first point being a midpoint of an edge of a first electrode plate, and the second point being a midpoint of an edge of a second electrode plate; a conversion step in which, based on a number of layers of the current winding layer, the position data of the first point is converted to obtain converted position data of the converted first point using a pre-set conversion matrix corresponding thereto; and a judgment step in which, based on the converted position data of the converted first point and the position data of the second point, misalignment data of the first electrode plate and the second electrode plate is calculated, and it is judged whether the misalignment data is within a threshold range, when within the threshold range, winding of a next winding layer is returned to be performed, and when not within the threshold range, an alarm is issued.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery winding method, a battery winding system, a battery, and an electrical device. Background Technology

[0002] With the continuous development of battery technology, higher precision requirements have been placed on the battery manufacturing process, and it is hoped that multiple factors can be considered simultaneously during the battery manufacturing process. Summary of the Invention

[0003] This application provides a battery winding method, a battery winding system, a battery, and an electrical device, which improves manufacturing precision during the battery manufacturing process and yields high-precision battery products.

[0004] In a first aspect, a battery winding method is provided, comprising: a winding step of winding a film composition of a battery to be manufactured onto a winding shaft, the film composition comprising a first electrode, a first separator, a second electrode, and a second separator stacked sequentially; an imaging step of capturing an image of the current winding layer using a camera component positioned at a fixed position each time the film composition is wound onto the winding shaft, the image of the current winding layer comprising a first region and a second region arranged side-by-side in a first direction perpendicular to the winding shaft, the first region containing the first electrode not yet wound onto the winding shaft, and the second region containing the second electrode already wound onto the winding shaft; and a position data acquisition step of acquiring position data of a first point in the first region and, based on the captured image of the current winding layer, acquiring position data of a first point in the second region. The process involves: acquiring the position data of the second point in the domain, where the first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction; a conversion step, based on the current winding layer number, using a pre-set conversion matrix corresponding to the current winding layer, converting the position data of the first point to obtain the converted position data of the first point; and a judgment step, based on the converted position data of the first point and the position data of the second point, calculating the misalignment data between the first electrode sheet and the second electrode sheet, and determining whether the misalignment data is within a threshold range. If the misalignment data is within the threshold range, the process returns to the winding step to wind the next winding layer; if the misalignment data is not within the threshold range, an alarm is issued.

[0005] The technical solution of this application embodiment involves winding the film composition of the battery to be manufactured onto a winding shaft. Each time a winding layer is wound, an image of the current winding layer is captured, and position data of the midpoint (first point) of the edge of the first electrode parallel to the first direction and the midpoint (second point) of the edge of the second electrode parallel to the first direction are obtained from the image of the current winding layer. Since the film composition has a certain thickness, the thickness of the wound gradually increases during the winding process. The first electrode side moves away from the camera assembly, while the second electrode side moves closer to the camera assembly, affecting the positions of the first and second electrodes in the image. That is, the position data of the first point of the first electrode and the second point of the second electrode obtained from the image include errors caused by thickness variations due to the winding of the film composition. Therefore, a pre-set transformation matrix is ​​used to convert the position data of the first point of the first electrode into the transformed position data of the first point, eliminating the errors caused by thickness variations due to the winding of the film composition. Then, based on the converted position data of the first point of the first electrode and the position data of the second point of the second electrode, the misalignment data between the first electrode and the second electrode is calculated. The misalignment data for each wound layer obtained in this way is not affected by errors caused by thickness variations due to the winding of the film composition.

[0006] Furthermore, by employing image processing and data processing methods, a transformation matrix is ​​used for each winding layer to eliminate errors caused by thickness variations due to the winding of the film composition. This allows for rapid elimination of such errors without affecting the efficiency of the entire winding process, enabling efficient and accurate winding.

[0007] In some embodiments, the conversion matrix is ​​preset through the following steps: First step, selecting a reference battery and using the camera assembly to capture images of each winding layer of the reference battery, wherein the image of each winding layer of the reference battery includes both the first region and the second region, similar to the image of the current winding layer obtained in the capturing step; Second step, based on the image of each winding layer of the reference battery, similar to the position data acquisition step, acquiring position data of the first point in the first region and position data of the second point in the second region; Third step, measuring the actual misalignment distance between the first electrode and the second electrode in each winding layer, and based on the actual misalignment distance, adjusting the position data of the second point... The process involves several steps: First, a correction is performed to obtain the corrected position data of the second point. Second, for each winding layer, a transformation matrix containing the parameters to be determined is set, and a relational expression is established based on the transformation matrix to correspond the position data of the first point to the corrected position data of the second point. Third, according to the number of parameters to be determined in the transformation matrix, a corresponding number of points are selected in the first region, including the first point, and corresponding numbers of points are selected in the second region, including the corrected second point. The selected points are substituted into the relational expression to obtain the parameters to be determined in the transformation matrix, thus obtaining the transformation matrix.

[0008] Following the steps of setting the conversion matrix described above, each winding layer of the reference battery is photographed using the same camera assembly used for photographing each winding layer of the battery to be manufactured. Then, similar to the position data acquisition step, the position data of the first point of the first electrode and the second point of the second electrode are obtained from the captured images. Here, the position data of the first point of the first electrode and the second point of the second electrode contain errors due to thickness variations caused by the winding of the film composition. Instead of acquiring these errors from the images, the actual misalignment distance between the first and second electrodes in each winding layer is measured. Using this actual misalignment distance, the position data of the second point of the second electrode is corrected to obtain the corrected position data of the second point. For each winding layer, a conversion matrix containing parameters to be determined is set. Based on the conversion matrix, a relationship is established that corresponds the position data of the first point to the corrected position data of the second point. The position data of several points are substituted into the relationship to obtain the parameters to be determined in the conversion matrix, thus obtaining the conversion matrix. Since for each winding layer, the actual misalignment distance between the first electrode and the second electrode is measured and corrected to the position data of the second point of the second electrode, and the position data of the first point of the first electrode and the second point of the second electrode contain errors caused by thickness changes due to the winding of the film composition, the transformation matrix to be determined used in the relationship between the first point and the corrected second point includes the influence caused by the thickness of the winding layer. The transformation matrix obtained by the transformation matrix to be determined can transform (correspond to) the first point to the second point that does not have errors caused by thickness changes due to the winding of the film composition and has no misalignment.

[0009] In some embodiments, in the fourth step, based on the transformation matrix F to be determined i The established relation is P. n T F i 'Q n =0……(1), where P n The image of the i-th winding layer of the reference battery includes the position data (x) of eight points selected within the first region from the first point. Pn ,y Pn ,1), where n is a natural number and 0≤n≤7, x Pn It is the coordinate in the first direction, y Pn It is the coordinate in the second direction perpendicular to the first direction, P n T For P n The transpose of Q n In the image of the i-th winding layer of the reference cell, the corrected second point is included within the second region along with P. n The corresponding location data of the 8 selected points (x Qn,y Qn ,1), where n is a natural number and 0≤n≤7, x Qn It is the coordinate in the first direction, y Qn It is the coordinate in the second direction, F i 'for It includes eight parameters to be determined, A11', A12', A13', A21', A22', A23', A31', and A32', representing that P will be used in the i-th winding layer. n Convert to Q n The relationship is as follows: i represents the number of winding layers. Based on the image obtained by photographing each winding layer of the reference battery, P is obtained. n and Q n , will P n and Q n Substitute the given relation P n T F i 'Q n =0, to obtain F for each winding layer. i The parameter to be determined in '.

[0010] In the fourth step of setting the transformation matrix, for the i-th winding layer of the reference cell, based on the transformation matrix F to be determined... i The relation established is P n T F i 'Q n =0. Where F i 'Contains 8 parameters to be determined, A11', A12', A13', A21', A22', A23', A31', and A32', which are set as a 3x3 matrix. Therefore, 8 sets of P are needed. n and Q n To obtain F i The eight parameters to be determined in 'P'. n This includes the first point of the first electrode in the image of the reference battery, and seven additional points selected in the first region where the first electrode is located. Q n This includes the corrected second point of the second electrode in the image of the reference battery, and seven other points selected in the second region where the second electrode is located, corresponding to seven other points selected in the first region. Therefore, for the i-th winding layer, the transformation matrix F to be determined, which transforms (corresponds to) the first point to the corrected second point, can be obtained. i The parameters to be determined in ' are used to obtain the transformation matrix F. i .

[0011] In some embodiments, during the transformation step, the transformation matrix is ​​used to establish equation (2) to convert the position data of the first point into the transformed position data of the transformed first point, P.T F i Q = 0……(2) where P is the position data (x) of the first point in the image of the current winding layer captured in the shooting step. P ,y P ,1), x P It is the coordinate in the first direction, y P In the image of the currently wound layer captured during the shooting step, the coordinates of the first point in a second direction perpendicular to the first direction are given by P. T The first point (x) is the transpose of P, and Q is the position data of the first point after transformation in the image of the current winding layer captured in the shooting step. Q ,y Q ,1), x Q In the image of the currently wound layer captured during the shooting step, the second point is located at the coordinates y in the first direction. Q F is the coordinate in the second direction to be determined. i for It contains 8 parameters A11, A12, A13, A21, A22, A23, A31, and A32, representing the relationship of converting P to Q in the i-th winding layer, where i represents the number of winding layers, and x P y P x Q and F i Substitute P T F i To find y, we need to set Q=0. Q In the image of the current winding layer captured during the shooting step, the coordinates in the second direction of the position data of the second point are taken and denoted as y. R Find y Q With y R The difference is used as misalignment data between the first electrode and the second electrode.

[0012] During the winding process of the battery to be manufactured, for each winding layer of the battery to be manufactured, the first point of the first electrode obtained from the captured image needs to be converted (corresponded to) to an ideal second point that is free from errors caused by thickness changes due to the winding of the film composition and without misalignment. Therefore, the relationship P is established. T F i Q = 0, where P is the position data of the first point, and Q is the transformed position data of the first point. This is achieved using a pre-defined transformation matrix F. i And the coordinates x of the first point in the first and second directions obtained from the image. P y P The first direction coordinates x of the second point QIt can determine the coordinates y in the second direction of the ideal second point. Q Here, the coordinates x in the first direction of the second point are... Q It is not affected by errors and misalignments caused by thickness variations due to the winding of the film composition; therefore, only the coordinates y of the second direction of the ideal second point need to be determined. Q That's it. At this point, the first point of the first electrode has been transformed (corresponding to) the second point of the ideal second electrode, by adjusting the coordinates y in the second direction of the transformed first point (ideal second point). Q The coordinates y of the second point obtained from the image of the wound layer in the second direction. R By performing the difference, the misalignment data between the first and second electrodes can be obtained without being affected by the error caused by the thickness variation due to the winding of the film composition.

[0013] In some embodiments, in the image of the currently wound layer captured in the shooting step, a first diaphragm that has not yet been wound onto the winding shaft appears in the first region, and a second diaphragm that has been wound onto the winding shaft appears in the second region. The first diaphragm and the second diaphragm extend beyond the first electrode and the second electrode respectively in a second direction perpendicular to the first direction. The first position data also includes position data of a third point of the first diaphragm in the first region and position data of a fourth point of the second diaphragm in the second region. The third point of the first diaphragm is the midpoint of the edge of the first diaphragm extending beyond the first electrode in the image of the currently wound layer, and the fourth point of the second diaphragm is the midpoint of the edge of the second diaphragm extending beyond the second electrode in the image of the currently wound layer. Based on the misalignment data of the first electrode and the second electrode, the first point, the second point, the third point, and the fourth point are marked on a straight line with the same coordinates in the first direction X, and the misalignment data between the first electrode, the first diaphragm, the second electrode, and the second diaphragm can be obtained.

[0014] During the winding process for manufacturing the battery, for each winding layer, the position data of the midpoint (the third point) of the first separator extending beyond the edge of the first electrode and the midpoint (the fourth point) of the second separator extending beyond the edge of the second electrode are obtained from the image. Based on the misalignment data of the first and second electrodes calculated above, the first point of the first electrode, the second point of the second electrode, the third point of the first separator, and the fourth point of the second separator can be marked on a straight line with the same coordinates in the first direction X. Thus, the misalignment data between the first electrode, the first separator, the second electrode, and the second separator can be obtained.

[0015] In a second aspect, a battery winding system is provided, comprising: a winding shaft for winding a film composition of a battery to be manufactured, the film composition comprising a first electrode, a first separator, a second electrode, and a second separator stacked sequentially; an imaging assembly spaced apart from the winding shaft and configured to capture images of each wound layer during the winding of the film composition to generate an image of the current wound layer, the image of the current wound layer including a first region and a second region arranged side-by-side in a first direction perpendicular to the winding shaft, wherein the first electrode is present in the first region but not yet wound onto the winding shaft, and the second electrode is present in the second region but already wound onto the winding shaft; and a control unit that performs the following processing: acquiring position data of a first point in the first region based on the captured image of the current wound layer. The position data of the second point is obtained in the second region. The first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction. Based on the current winding layer number, a pre-set transformation matrix corresponding to the current winding layer is used to transform the position data of the first point to obtain the transformed position data of the first point. Based on the transformed position data of the first point and the position data of the second point, the misalignment data between the first electrode sheet and the second electrode sheet is calculated. It is determined whether the misalignment data is within a threshold range. When the misalignment data is within the threshold range, the winding step is returned to perform the winding of the next winding layer. When the misalignment data is not within the threshold range, an alarm is issued.

[0016] Thirdly, a battery is provided in which the battery winding method of the first aspect is used in the manufacturing process of the battery.

[0017] Fourthly, an electrical device is provided, which includes the battery of the third aspect, said battery being used to provide electrical energy. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of a battery winding system according to an embodiment of this application;

[0020] Figure 2 This is a diagram illustrating the effect of the thickness of the film composition wound when the camera assembly in the battery winding system of one embodiment of this application takes a picture;

[0021] Figure 3This is a diagram showing the misalignment of the first electrode and the second electrode when the battery winding method of one embodiment of this application is not used;

[0022] Figure 4 This is a flowchart illustrating a battery winding method according to an embodiment of this application;

[0023] Figure 5 This is a flowchart illustrating the steps of setting a transformation matrix in one embodiment of this application;

[0024] Figure 6A This is a diagram showing the first and second points selected when obtaining the parameters to be determined in the transformation matrix according to an embodiment of this application; Figure 6B This is a diagram showing the first point and the corrected second point when obtaining the parameter to be determined in the transformation matrix according to an embodiment of this application; Figure 6C This is a graph showing the points selected in the first region and the corresponding points selected in the second region when calculating the parameters to be calculated in the transformation matrix according to an embodiment of this application.

[0025] Figure 7A This is a diagram showing the first and second points selected in the position data acquisition step of a battery winding method according to an embodiment of this application; Figure 7B This is a diagram of the first and second points that have been converted in the conversion and calculation steps of a battery winding method according to an embodiment of this application.

[0026] Figure 8A This is a diagram showing the first, second, third, and fourth points selected in a battery winding method according to an embodiment of this application; Figure 8B This is a diagram showing a battery winding method according to one embodiment of the present application, in which the first point, the second point, the third point, and the fourth point are marked on a straight line with the same coordinates in the first direction X;

[0027] Figure 9 This is a diagram illustrating the effect of a battery winding method according to an embodiment of this application. Specific Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0034] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack, etc.

[0035] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated current collector protrudes from the coated current collector, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated current collector protrudes from the coated current collector, serving as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, etc. To ensure that a large current can be carried without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The diaphragm can be made of PP or PE, etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiment in this application uses a wound structure.

[0036] With the continuous development of battery technology, higher requirements have been placed on the battery manufacturing process, and it is hoped that multiple factors can be considered simultaneously during the battery manufacturing process.

[0037] Lithium-ion batteries possess advantages such as light weight and small size, high energy density, high power density, high operating voltage, high cycle life, good safety, and environmental friendliness, making them widely used in various fields, including portable smart devices and electric vehicles. Lithium-ion batteries mainly include wound lithium-ion batteries and stacked lithium-ion batteries. In the manufacturing process of wound lithium-ion batteries, the positive electrode, negative electrode, and separator need to be wound. Ideally, the relative positions of the positive electrode, negative electrode, and separator should not change during the winding process. However, misalignment usually occurs as winding progresses. If the misalignment exceeds ±0.5mm, the resulting battery poses a risk of internal short circuit, potentially leading to explosion and fire. Therefore, it is necessary to monitor the misalignment between the positive electrode, negative electrode, and separator during the battery winding process to ensure it remains within a specified threshold range.

[0038] In existing technologies, the process typically involves photographing the positive electrode, negative electrode, and separator as they are being wound, and then using the captured images to determine the misalignment between them. However, as the positive electrode, negative electrode, and separator are wound layer by layer on the winding shaft, the thickness of the wound increases, which affects the position of the positive electrode, negative electrode, and separator in the image, resulting in errors between the actual positions and the actual positions.

[0039] In view of this, this application provides a technical solution, providing a battery winding method, comprising: a winding step, winding a film composition of a battery to be manufactured onto a winding shaft, wherein the film composition comprises a first electrode, a first separator, a second electrode, and a second separator stacked sequentially; an imaging step, wherein each time the film composition is wound into a winding layer on the winding shaft, an image of the current winding layer is captured using a camera component positioned at a fixed position, wherein the image of the current winding layer includes a first region and a second region arranged side by side in a first direction perpendicular to the winding shaft, wherein the first electrode is present in the first region but not yet wound onto the winding shaft, and the second electrode is present in the second region but already wound onto the winding shaft; and a position data acquisition step, acquiring position data of a first point in the first region based on the captured image of the current winding layer, and... In the second region, the position data of the second point is obtained. The first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction. A conversion step is performed: based on the current winding layer number, a pre-set conversion matrix corresponding to the current winding layer is used to convert the position data of the first point to obtain the converted position data of the first point. A judgment step is performed: based on the converted position data of the first point and the position data of the second point, the misalignment data between the first and second electrodes is calculated, and it is determined whether the misalignment data is within a threshold range. If the misalignment data is within the threshold range, the winding process is returned to the winding step to wind the next winding layer. If the misalignment data is not within the threshold range, an alarm is issued.

[0040] The technical solution of this application embodiment involves winding the film composition of the battery to be manufactured onto a winding shaft. Each time a winding layer is wound, an image of the current winding layer is captured, and position data of the midpoint (first point) of the edge of the first electrode parallel to the first direction and the midpoint (second point) of the edge of the second electrode parallel to the first direction are obtained from the image of the current winding layer. Since the film composition has a certain thickness, the thickness of the wound gradually increases during the winding process. The first electrode side moves away from the camera assembly, while the second electrode side moves closer to the camera assembly, affecting the positions of the first and second electrodes in the image. That is, the position data of the first point of the first electrode and the second point of the second electrode obtained from the image include errors caused by thickness changes due to the winding of the film composition. Therefore, a pre-set transformation matrix is ​​used to convert the position data of the first point of the first electrode into the transformed position data of the first point, eliminating the errors caused by thickness changes due to the winding of the film composition. Then, based on the converted position data of the first point of the first electrode and the position data of the second point of the second electrode, the misalignment data between the first electrode and the second electrode is calculated. The misalignment data for each wound layer obtained in this way is not affected by errors caused by thickness variations due to the winding of the film composition.

[0041] Furthermore, the technical solution of this application embodiment uses image processing and data processing methods to eliminate errors caused by thickness variations due to the winding of the film composition for each winding layer using a transformation matrix. This can quickly eliminate the error without affecting the efficiency of the entire winding process, enabling efficient and accurate winding.

[0042] This application provides a battery winding system, comprising: a winding shaft for winding a film composition of a battery to be manufactured, the film composition comprising a first electrode, a first separator, a second electrode, and a second separator stacked sequentially; an imaging assembly, spaced apart from the winding shaft and used to capture images of each wound layer during the winding process of the film composition to generate an image of the current wound layer, the image of the current wound layer including a first region and a second region arranged side-by-side in a first direction perpendicular to the winding shaft, the first region containing the first electrode not yet wound on the winding shaft, and the second region containing the second electrode wound on the winding shaft; and a control unit, the control unit performing the following processing: acquiring position data of a first point in the first region based on the captured image of the current wound layer, and... In the second region, the position data of the second point is obtained. The first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction. Based on the current winding layer number, a pre-set transformation matrix corresponding to the current winding layer is used to transform the position data of the first point to obtain the transformed position data of the first point. Based on the transformed position data of the first point and the position data of the second point, the misalignment data between the first electrode sheet and the second electrode sheet is calculated. It is determined whether the misalignment data is within a threshold range. When the misalignment data is within the threshold range, the winding step is returned to perform the winding of the next winding layer. When the misalignment data is not within the threshold range, an alarm is issued.

[0043] This application also provides a battery in which the battery winding method of this application is used in the battery manufacturing process.

[0044] This application also provides an electrical device comprising a battery manufactured using the battery winding method of this application, the battery being used to provide electrical energy.

[0045] The technical solutions described in this application are applicable to the manufacture of wound batteries, and can be used in, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, electric vehicles, ships, and spacecraft, including aircraft, rockets, space shuttles, and spacecraft. It should be understood that the wound batteries manufactured using the technical solutions described in this application are not limited to the devices described above, but can also be applied to all devices that use wound batteries.

[0046] For example, such as Figure 1 As shown in the structural diagram, a battery winding system 1 of one embodiment of this application includes a film composition 10, an unwinding roller 20, a guide roller 30 and a winding shaft 40, for winding a battery to be manufactured.

[0047] The membrane composition 10 is the core component for the battery to achieve repeated charge and discharge. Typically, the membrane composition includes electrodes and a separator. In some optional embodiments, the electrodes are two-layered, namely a first electrode 101 and a second electrode 103, and the separator is two-layered, namely a first separator 102 and a second separator 104. The first electrode 101, the first separator 102, the second electrode 103, and the second separator 104 are stacked sequentially. During battery manufacturing, the two electrode layers and the two separator layers need to be wound together.

[0048] In some alternative embodiments, four unwinding rollers 20 are provided, with a first electrode 101, a first diaphragm 102, a second electrode 103, and a second diaphragm 104 respectively placed on the four unwinding rollers 20, and their free ends released from the four unwinding rollers 20 respectively.

[0049] In some alternative embodiments, the guide rollers 30 can be set individually or in pairs. The free ends of the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104 are guided to the winding shaft 40 in a stacked manner after passing through multiple guide rollers 30.

[0050] In some alternative embodiments, the winding shaft 40 is rotatable under the action of a power mechanism (not shown) and is capable of winding the stacked first electrode 101, first diaphragm 102, second electrode 103 and second diaphragm 104, i.e., the membrane composition 10, thereon.

[0051] Optionally, the winding shaft 40 consists of two semi-circular clamps joined together to form a cylindrical winding shaft 40. When winding is required, the strip-shaped first electrode 101, first diaphragm 102, second electrode 103, and second diaphragm 104 are pulled onto the winding shaft 40, and the winding shaft 40 is used to fix the free ends of the first electrode 101, first diaphragm 102, second electrode 103, and second diaphragm 104 to the winding shaft 40; that is, the free ends of the four components are clamped between the two semi-circular clamps. Then, using a motor as a power mechanism, the winding shaft 40 is rotated, pulling the stacked first electrode 101, first diaphragm 102, second electrode 103, and second diaphragm 104 onto the winding shaft 40 and winding them onto the winding shaft 40.

[0052] Due to the processing technology of the electrodes and separators, as well as the positional fluctuations of the electrodes and separators during the conveyor belt process, misalignment may occur between electrodes and between electrodes and separators during the winding process. To avoid such misalignment, it is necessary to monitor the relative positions between electrodes and between electrodes and separators in real time. Typically, the edge of the electrode (or separator) is used as a reference to monitor the relative positions between electrodes and between electrodes and separators in real time.

[0053] In some alternative embodiments, such as Figure 1 As shown, the battery winding system 1 also includes a camera assembly 50 and a control unit 60.

[0054] In some optional embodiments, the camera assembly 50 is fixedly positioned at a certain distance from the winding shaft 40 in a third direction Z (as described below, the first direction X is perpendicular to the axial direction of the winding shaft 40, the second direction Y is the axial direction of the winding shaft 40, and the third direction Z is perpendicular to the first direction X and the second direction Y), for capturing images of the film composition 10 during winding to generate images. The distance between the camera assembly 50 and the winding shaft 40 ensures that during winding, the camera assembly 50 can at least capture images of the edges of the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104 parallel to the first direction X. The first direction X is perpendicular to the axial direction of the winding shaft 40. The second direction Y is the axial direction of the winding shaft 40 and is perpendicular to the first direction X. The third direction Z is perpendicular to both the first direction X and the second direction Y.

[0055] In some optional embodiments, the control unit 60 is communicatively connected to the camera assembly 50 to receive images captured by the camera assembly 50 and process the images to calculate the positions of the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104, thereby obtaining misalignment data between the electrodes and between the electrodes and the diaphragm.

[0056] However, because the film composition 10 has a certain thickness, the thickness of the wound 70 formed by winding the film composition 10 gradually increases during the process of winding it onto the winding shaft 40. For example... Figure 2 As shown, the thickness of the wound material 70 gradually increases in the third direction Z, which separates the imaging component 50 from the winding shaft 40. As the thickness of the wound material 70 increases, the first electrode 101 side within the imaging range of the imaging component 50 gradually moves away from the imaging component 50 in the third direction Z, while the second electrode 103 side gradually moves closer to the imaging component 50 in the third direction Z. Although this positional change in the third direction Z is not directly reflected in the captured image, it affects the position of the first electrode 101 and the second electrode 103 in the second direction Y in the image. In other words, the positional data of the first electrode 101 and the second electrode 103 obtained from the image include errors caused by the thickness variation due to the winding of the film composition 10.

[0057] To illustrate the impact of errors caused by thickness variations due to the winding of the film composition 10, the inventors used a camera assembly 50 to photograph each layer of the film composition 10 wound on the winding shaft 40, and extracted the position data (pixel coordinates) of the first electrode 101 and the second electrode 103 from the captured images, such as... Figure 3The diagram shows how it was drawn.

[0058] Figure 3 middle, Figure 3 (a) represents the pixel coordinates of the midpoint of the edge L1 of the first pole piece 101 parallel to the first direction X in the second direction Y in each winding layer, where the horizontal axis represents the number of winding layers and the vertical axis represents the pixel coordinates in the second direction Y. Figure 3 (b) represents the pixel coordinates of the midpoint of the edge L2 of the second pole piece 103 parallel to the first direction X in the second direction Y in each winding layer, where the horizontal axis represents the number of winding layers and the vertical axis represents the pixel coordinates in the second direction Y. Figure 3 (c) represents the absolute value of the difference (misalignment data) between the midpoint of the edge L1 of the first electrode 101 parallel to the first direction X and the midpoint of the edge L2 of the second electrode 103 parallel to the first direction X in the second direction Y in each winding layer, where the horizontal axis represents the number of winding layers and the vertical axis represents the pixel coordinates in the second direction Y. Figure 3 (d) indicates that Figure 3 The graph of (c) after converting the vertical axis to the actual distance, where the horizontal axis represents the number of layers of the winding and the vertical axis represents the actual distance.

[0059] according to Figure 3 It can be seen that as the number of winding layers increases, the thickness of the wound material 70 gradually increases. The pixel coordinates of the midpoint of the edge L1 of the first electrode 101 in the second direction Y decrease sharply after the 13th winding layer, while the pixel coordinates of the midpoint of the edge L2 of the second electrode 103 in the second direction Y gradually increase. The distance between the midpoints of the edges L1 and L2 of the first electrode 101 and the second electrode 103 in the second direction Y increases sharply after the 13th winding layer. During the winding process, as the number of winding layers increases, the actual misalignment between the first electrode 101 and the second electrode 103 is affected by various factors and often fluctuates. Therefore, Figure 3 The results are affected by errors caused by thickness variations due to the winding of the film composition 10. Therefore, misjudgment may occur when determining whether the misalignment between the first electrode 101 and the second electrode 103 exceeds the threshold.

[0060] Furthermore, since the first diaphragm 102 and the second diaphragm 104 are respectively located on the side of the first electrode 101 and the side of the second electrode 103 within the imaging range of the imaging assembly 50, their positions in the image are also affected by errors caused by thickness variations due to the winding of the film composition 10 for the same reasons as described above.

[0061] Therefore, in one embodiment of the battery winding method of this application, by eliminating the error caused by thickness variation due to winding of the film composition 10 for each winding layer, high-precision winding can be performed during battery manufacturing, resulting in a battery with high safety. Image and data processing in the battery winding method is performed by the control unit 60.

[0062] Figure 4 This is a flowchart illustrating a battery winding method according to an embodiment of this application. Figure 5 This represents a pre-defined transformation matrix F in one embodiment of this application. i The flowchart for each step. Figure 6A This represents the process of obtaining the transformation matrix F in one embodiment of this application. i When determining the parameters to be determined in ', the first point A0 and the second point B0 are selected in the graph. Figure 6B This represents the process of obtaining the transformation matrix F in one embodiment of this application. i The graph shows the first point A0 and the corrected second point B0 when the parameter to be determined is in '. Figure 6C This represents the process of obtaining the transformation matrix F in one embodiment of this application. i When determining the parameters in ', the graph shows the points selected in the first region A and the corresponding points selected in the second region B. Figure 7A This is a diagram showing the first point A0 and the second point B0 selected in the position data acquisition step S13 of the battery winding method according to an embodiment of this application. Figure 7B This is a diagram of the converted first point A0” and second point B0 in the conversion step S14 and calculation step of the battery winding method according to an embodiment of this application. Figure 8A This diagram illustrates the selected first point A0, second point B0, third point C0, and fourth point D0 in a battery winding method according to an embodiment of this application. Figure 8B This is a diagram in one embodiment of the battery winding method of this application, in which the first point A0, the second point B0, the third point C0 and the fourth point D0 are marked on a straight line with the same coordinates in the first direction X.

[0063] In some alternative implementations, such as Figure 4As shown, the battery winding method includes a winding step S11, an imaging step S12, a position data acquisition step S13, a conversion step S14, and a judgment step S15. In the winding step S11, the film composition 10 of the battery to be manufactured is wound onto the winding shaft 40. The film composition 10 includes a first electrode 101, a first separator 102, a second electrode 103, and a second separator 104 stacked sequentially. In the imaging step S12, whenever the film composition 10 is wound onto the winding shaft 40 as one layer, an image of the current winding layer is captured by a camera component 50 set at a fixed position. The image of the current winding layer includes a first region A and a second region B arranged side by side in a first direction X perpendicular to the winding shaft 40. The first electrode 101, which has not yet been wound onto the winding shaft 40, appears in the first region A, and the second electrode 103, which has been wound onto the winding shaft 40, appears in the second region B. In the position data acquisition step S13, based on the captured image of the current winding layer, the position data of the first point A0 in the first region A and the position data of the second point B0 in the second region B are acquired. The first point A0 is the midpoint of the edge L1 of the first electrode 101 parallel to the first direction X, and the second point B0 is the midpoint of the edge L2 of the second electrode 103 parallel to the first direction X. In the conversion step S14, based on the current winding layer number i, a pre-set conversion matrix F corresponding to the current winding layer is used. i The position data of the first point A0 is transformed to obtain the transformed position data of the first point A0". In the judgment step S15, based on the transformed position data of the first point A0” and the position data of the second point B0, the misalignment data between the first electrode 101 and the second electrode 103 is calculated, and it is determined whether the misalignment data is within the threshold range. If the misalignment data is within the threshold range, the winding step S11 is returned to perform the winding of the next winding layer. If the misalignment data is not within the threshold range, an alarm is issued.

[0064] When the film composition 10 of the battery to be manufactured is wound onto the winding shaft 40, an image of the current winding layer is captured each time a winding layer is wound, and the image is obtained as follows: Figure 7AAs shown, from the image of the current winding layer, the position data of the midpoint of the edge L1 of the first electrode 101 parallel to the first direction X (i.e., the first point A0) and the midpoint of the edge L2 of the second electrode 103 parallel to the first direction X (i.e., the second point B0) are obtained. Since the film composition 10 has a certain thickness, during the process of winding it onto the winding shaft 40, the thickness of the wound 70 formed by the film composition 10 gradually increases, with the first electrode side moving away from the camera assembly and the second electrode side moving closer to the camera assembly. This affects the position of the first electrode 101 and the second electrode 103 in the second direction Y in the image. That is, the position data of the first point A0 of the first electrode 101 and the second point B0 of the second electrode 103 obtained from this image include errors caused by the thickness change due to the winding of the film composition 10. Therefore, a pre-set transformation matrix F is used... i The position data of the first point A0 of the first electrode 101 is converted into the converted position data of the first point A0”. Specifically, the first point A0 of the first electrode 101 is mapped to the ideal second point B0 of the second electrode 102 (the converted first point A0”), and the position data of the ideal second point B0” is obtained. This eliminates the error caused by the thickness variation due to the winding of the film composition 10. Then, based on the converted position data of the first point A0” of the first electrode 101 and the position data of the second point B0 of the second electrode 103, the misalignment data of the first electrode 101 and the second electrode 103 is calculated. The misalignment data of each wound layer obtained in this way is not affected by the error caused by the thickness variation due to the winding of the film composition 10.

[0065] Furthermore, by employing image processing and data processing methods, for each winding layer, the transformation matrix F is used. i This eliminates errors caused by thickness variations due to the winding of the film composition 10, and can quickly eliminate these errors without affecting the efficiency of the entire winding process, enabling efficient and accurate winding.

[0066] In some alternative embodiments, such as Figure 5 As shown, the transformation matrix F i The settings are pre-defined through steps S01, S02, S03, S04, and S05. In step S01, a reference battery is selected, and each winding layer of the reference battery is photographed using the camera assembly 50, such as... Figures 6A to 6CAs shown, the image of each winding layer of the reference battery, like the image of the current winding layer obtained in step S12, includes a first region A and a second region B. In the second step S02, based on the image of each winding layer of the reference battery, similar to the position data acquisition step S13, the position data of the first point A0 is acquired in the first region A, and the position data of the second point B0 is acquired in the second region B. In the third step S03, the actual misalignment distance between the first electrode 101 and the second electrode 103 in each winding layer is measured, and the second point B0 is corrected based on the actual misalignment distance to obtain the corrected position data of the second point B0. In the fourth step S04, for each winding layer, a transformation matrix F containing the parameters to be determined is set. i Based on the transformation matrix F to be determined i 'Establish a relational expression (i.e., equation (1) described later) that corresponds to the position data of the first point A0 and the corrected position data of the second point B0.' In the fifth step S05, based on the transformation matrix F to be determined... i Given the number of parameters to be determined, select a corresponding number of points in the first region A, including the first point A0. Correspondingly, select a corresponding number of points in the second region B, including the corrected second point B0. Substitute the selected points into the relational expression to obtain the transformation matrix F. i The parameters of ' are used to obtain the transformation matrix F. i .

[0067] Based on the above-mentioned setting of transformation matrix F i In each step S01 to S05, using the same camera assembly 50 as that used for photographing each winding layer of the battery to be manufactured, each winding layer of the reference battery is photographed. Then, similar to the position data acquisition step S13, the position data of the first point A0 of the first electrode 101 and the second point B0 of the second electrode 103 are acquired from the photographed images. Here, the position data of the first point A0 of the first electrode 101 and the second point B0 of the second electrode 103 contain errors due to thickness variations caused by the winding of the film composition 10. At this time, instead of acquiring the data from the images, the actual misalignment distance between the first electrode 101 and the second electrode 103 in each winding layer is actually measured. Using this actual misalignment distance, the position data of the second point B0 of the second electrode 103 is corrected to obtain the corrected position data of the second point B0'. For each winding layer, a transformation matrix F containing the parameters to be determined is set. i Based on the transformation matrix F to be determined i Establish a relational expression that corresponds the position data of the first point A0 to the corrected position data of the second point B0. Substitute the position data of several points into the relational expression to obtain the transformation matrix F to be determined. i The parameters to be determined in ' are used to obtain the transformation matrix F. i .

[0068] Since the actual misalignment distance between the first electrode 101 and the second electrode 103 was measured for each wound layer and corrected to the position data of the second point B0 of the second electrode 103, and since there are errors in the position data of the first point A0 of the first electrode 101 and the second point B0 of the second electrode 103 due to thickness variations caused by the winding of the film composition 10, the transformation matrix F to be determined in the relationship between the first point A0 and the corrected second point B0' is... i ', including the effect caused by the thickness of the winding layer, through the transformation matrix F to be determined. i The resulting transformation matrix F i It can convert (correspond to) the first point A0 to the second point B0, which has no error caused by thickness change due to the winding of the film composition 10 and no misalignment.

[0069] In some alternative implementations, a two-dimensional measuring instrument is used, for example, to measure the actual misalignment distance between the first electrode 101 and the second electrode 103 in each winding layer. Two-dimensional measuring instruments are widely used to measure angles, diameters, radii, distances from a point to a line, eccentricities of two circles, distances between two points, etc., and can accurately measure actual dimensions.

[0070] In some optional embodiments, in the fourth step S04, based on the transformation matrix F to be determined... i The established relation is

[0071] P n T F i 'Q n =0……(1).

[0072] Among them, P n The image of the i-th winding layer of the reference cell contains the position data (x) of eight points selected in the first region A, including the first point A0. Pn ,y Pn ,1), where n is a natural number and 0≤n≤7, x Pn It is the coordinate in the first direction X, y Pn P is the coordinate in the second direction Y, which is perpendicular to the first direction X. n T For P n The transpose of Q. n In the image of the i-th winding layer of the reference cell, including the corrected second point B0', in the second region B, with P n The corresponding location data of the 8 selected points (x Qn ,y Qn ,1), where n is a natural number and 0≤n≤7, x Qn It is the coordinate in the first direction X, yQn It is the coordinate in the second direction, Y. F i 'for It contains 8 parameters to be determined, A11', A12', A13', A21', A22', A23', A31', and A32', representing the P in the i-th winding layer. n Convert to Q n The relationship is as follows: i represents the number of winding layers. Based on images obtained from each winding layer of the reference battery, P is obtained. n and Q n , will P n and Q n Substitute into relation P n T F i 'Q n =0, to obtain F for each winding layer. i The parameters to be determined in '.

[0073] In setting the transformation matrix F i In the fourth step S04, for the i-th winding layer of the reference battery, based on the transformation matrix F to be determined... i The relation established is P n T F i 'Q n =0. Where F i 'Contains 8 parameters A11', A12', A13', A21', A22', A23', A31', and A32', and sets them as a 3-order matrix. Therefore, at least 8 sets of P are needed. n and Q n To obtain F i The eight parameters in '. P n The image includes a first point A0 of the first electrode 101 in the reference battery image, and seven other points selected in the first region A where the first electrode 101 is located. n The image includes the corrected second point B0' of the second electrode 103 in the image of the reference battery, and seven other points selected in the second region B where the second electrode 103 is located, corresponding to seven other points selected in the first region A. Therefore, for the i-th winding layer, the transformation matrix F that transforms (corresponds to) the first point A0 to the corrected second point B0' can be obtained. i The parameters to be determined in ' are used to obtain the transformation matrix F. i .

[0074] In some optional embodiments, within the first region A, nine points A0 to A8 are established in a grid pattern, centered on the first point A0. The actual distance between A0 to A8 in the first direction X and the second direction Y is taken as dmm (d millimeters). This distance dmm is converted into pixel dimensions in the image and marked in the figure. P n This includes any 8 points, including the first point A0, selected from A0 to A8.

[0075] In some optional embodiments, within the second region B, nine points B0' to B8, including the corrected second point B0', are established in a crisscross pattern, centered on the corrected second point B0'. Similarly, the actual distance between B0' to B8 in the first direction X and the second direction Y is taken as dmm (d millimeters), and this distance dmm is converted into pixel dimensions in the image and labeled in the figure. Q n This includes any 8 points from B0' to B8 selected in this way, including the corrected second point B0'.

[0076] In some alternative embodiments, the method of selecting 8 points, including the first point A0, in the first region A can also be to take a circle with the first point A0 as the center and rmm (r millimeters) as the radius, and select another 7 points at equal intervals or arbitrarily on the circumference.

[0077] In some alternative embodiments, the method of selecting 8 points in the second region B, including the corrected second point B0', can also be to take a circle with the corrected second point B0' as the center and rmm (r millimeters) as the radius, and select another 7 points at equal intervals or arbitrarily on the circumference.

[0078] In some optional embodiments, the method of selecting eight points, including the first point A0, in the first region A is the same as the method of selecting eight points, including the corrected second point B0', in the second region B. That is, eight points, including the first point A0, are selected in the first region A, and correspondingly, eight points, including the corrected second point B0', are selected in the second region B. Here, "correspondence" refers to a correspondence in actual distance or actual positional relationship.

[0079] In some optional embodiments, in transformation step S14, the transformation matrix F is used. i Formula (2) is established to convert the position data of the first point A0 into the transformed position data of the first point A0".

[0080] P T F i Q = 0……(2).

[0081] Where P is the position data (x, y) of the first point A0 in the image of the current winding layer captured in step S12. P ,y P ,1), x P It is the coordinate in the first direction X, y P In the image of the current winding layer captured in step S12, the coordinates of the first point A0 in the second direction Y, which is perpendicular to the first direction X, are P. T This is the transpose of P. Q is the transformed data (x) of the position of the first point A0 in the image of the current winding layer captured in step S12. Q ,y Q ,1), x Q In the image of the current wound layer captured in step S12, the coordinates of the second point B0 in the first direction X are y Q F is the coordinate in the second direction Y that needs to be determined. i for It contains eight parameters A11, A12, A13, A21, A22, A23, A31, and A32, representing the relationship of converting P to Q in the i-th winding layer. i represents the number of winding layers. x P y P x Q and F i Substitute P T F i To find y, we need to set Q=0. Q In the image of the current winding layer captured in step S12, the coordinates in the second direction Y of the position data of the second point B0 are taken and set as y. R Find y Q With y R The difference is used as misalignment data between the first electrode 101 and the second electrode 103.

[0082] During the winding process of the battery to be manufactured, for each winding layer of the battery to be manufactured captured by photography, the first point A0 of the first electrode 101 obtained from it needs to be converted (corresponding) to an ideal second point B0 that is free from errors caused by thickness changes due to the winding of the film composition 10 and without misalignment. Therefore, the relationship P is established. T F i Q = 0, where P is the position data of the first point A0, and Q is the transformed position data of the first point A0”, which is also the position data of the ideal second point B0”. This is achieved using a pre-defined transformation matrix F. i And the coordinates x in the first direction X and the second direction Y of the first point A0 obtained from the image. P y P The coordinates x of the first direction X of the second point B0 QIt is possible to obtain the coordinates y in the second direction Y of the ideal second point B0". Q Here, the coordinate x of the first direction X of the second point B0 is... Q It is not affected by errors and misalignments caused by thickness variations due to the winding of the film composition 10, therefore only the coordinates y of the second direction Y of the ideal second point B0” are determined. Q That's it. At this point, the first point A0 of the first electrode 101 has been transformed (corresponding to) the ideal second point B0 of the second electrode 103 by adjusting the coordinates y in the second direction Y of the transformed first point A0 (ideal second point B0). Q The coordinates of the second point B0 obtained from the image of the wound layer in the second direction Y are y. R By subtracting the difference, the misalignment data of the first electrode 101 and the second electrode 103 can be obtained without being affected by the error caused by the thickness change due to the winding of the film composition 10.

[0083] In addition, P n For (x) Pn ,y Pn ,1), Q n For (x) Qn ,y Qn ,1), P is (x P ,y P ,1) and Q is (x Q ,y Q ,1), while the actual coordinates obtained in the image are only the coordinates in the first direction X and the second direction Y, P n Q n P and Q should actually only include the first two terms. However, to improve accuracy, the transformation matrix F is set... i It includes 8 parameters A11, A12, A13, A21, A22, A23, A31, and A32, therefore F i Set as a 3x3 matrix The corresponding transformation matrix F to be determined i 'for To find the 3rd order transformation matrix F i The parameters in ' are used to obtain the transformation matrix F i In P n Q n Add 1 as the third term to P and Q.

[0084] In some optional embodiments, in the image of the currently wound layer captured in step S12, a first diaphragm 102 not yet wound onto the winding shaft 40 appears in a first region A, and a second diaphragm 104 wound onto the winding shaft 40 appears in a second region B. The first diaphragm 102 and the second diaphragm 104 extend beyond the first electrode 101 and the second electrode 103 respectively in a second direction Y perpendicular to the first direction X. The first position data also includes the position data of the third point C0 of the first diaphragm 102 in the first region A and the position data of the fourth point D0 of the second diaphragm 104 in the second region B. The third point C0 is the midpoint of the edge L3 of the first diaphragm 102 extending beyond the first electrode 101 in the current image of the wound layer. The fourth point D0 of the second diaphragm 104 is the midpoint of the edge L4 of the second diaphragm 104 extending beyond the second electrode 103 in the current image of the wound layer. Based on the misalignment data of the first electrode 101 and the second electrode 103, the first point A0, the second point B0, the third point C0, and the fourth point D0 are marked on a straight line with the same coordinates in the first direction X. This allows us to obtain the misalignment data between the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104.

[0085] During the winding process of manufacturing the battery, for each winding layer, the position data of the midpoint of the first separator 102 beyond the edge L3 of the first electrode 101 (i.e., the third point C0) and the midpoint of the second separator 104 beyond the edge L4 of the second electrode 103 (i.e., the fourth point D0) are obtained from the image. Based on the misalignment data of the first electrode 101 and the second electrode 103 calculated above, the first point A0 of the first electrode 101, the second point B0 of the second electrode 103, the third point C0 of the first separator 102, and the fourth point D0 of the second separator 104 can be marked on a straight line with the same coordinates in the first direction X. Thus, the misalignment data between the first electrode 101, the first separator 102, the second electrode 103, and the second separator 104 can be obtained.

[0086] Additionally, it should be noted that during the winding process, the edges of the membrane winding 10 may not be strictly parallel to the first direction X (i.e., perpendicular to the winding axis), which is one of the reasons for misalignment between electrodes and between electrodes and the separator. Therefore, the "edge parallel to the first direction X" mentioned in this specification is not strictly parallel, but rather refers to an edge that is approximately parallel to the first direction X. Since the misalignment threshold between the first electrode and the second electrode is ±0.5 mm, which is very small, "approximately parallel to the first direction X" is visually equivalent to an edge parallel to the first direction X.

[0087] Furthermore, the coordinates mentioned in this specification can be pixel coordinates obtained from the image, or actual coordinates converted from pixel coordinates.

[0088] The following describes the flow of the battery winding method in some optional embodiments.

[0089] First, for the transformation matrix F i Make the preset settings.

[0090] A wound battery was selected as a reference battery, disassembled, and each wound layer was photographed using the camera component 50.

[0091] like Figure 6A As shown, in the captured image of the i-th winding layer of the reference battery, in the first region A, the midpoint of the edge L1 of the first electrode 101 parallel to the first direction X is selected as the first point A0. And in the second region B, the midpoint of the edge L2 of the second electrode 103 parallel to the first direction X is selected as the second point B0.

[0092] Then, as Figure 6B As shown, the actual misalignment distance (distance in the second direction Y) between the first electrode 101 and the second electrode 103 in the i-th winding layer of the reference battery is measured using a two-dimensional measuring instrument, and corrected to the second point B0 to obtain the corrected second point B0'.

[0093] Next, as Figure 6C As shown, in the first region A, nine points A0 to A8 are established in a crisscross pattern, centered on the first point A0. The actual distance between A0 to A8 in the first direction X and the second direction Y is dmm. This distance dmm is converted into pixel size in the image and labeled A1 to A8. Similarly, in the second region B, nine points B0' to B8 are established in a crisscross pattern, centered on the corrected second point B0'. Likewise, the actual distance between B0' to B8 in the first direction X and the second direction Y is dmm. This distance dmm is converted into pixel size in the image and labeled B1 to B8. Thus, the corresponding A0 to A8 and B0' to B8 are obtained.

[0094] Next, based on the transformation matrix F containing the parameters to be determined... i ', establish P n T F i 'Q n =0. P n (x Pn ,y Pn ,1) represents the location data of any 8 points from A0 to A8, including A0. Q n (x Qn ,y Qn,1) represents the position data of any 8 points from B0' to B8, including B0'. i 'for It contains eight parameters to be determined: A11', A12', A13', A21', A22', A23', A31', and A32'. Therefore, select any seven corresponding sets of points from A1 to A8 and B1 to B8, and substitute them along with A0 and B0' into P. n T F i 'Q n Given 0, we can find F. i The eight parameters to be determined are obtained by extracting F from all the parameters to be determined. i F i That is, the transformation matrix of the i-th winding layer, which can transform the first point A0 to the ideal second point B0 during the winding process of the battery to be manufactured.

[0095] The corresponding transformation matrix F was obtained for each winding layer. i After determining the parameters to be solved in ', the transformation matrix F is pre-defined. i The processing flow has ended. The pre-set transformation matrix F i It will be applied to the winding process of the battery to be manufactured.

[0096] During the winding process of the battery to be manufactured, firstly, for each winding layer, the current winding layer is photographed using the camera component 50.

[0097] like Figure 7A As shown, in the captured image of the current winding layer of the battery to be manufactured, in the first region A, the midpoint of the edge L1 of the first electrode 101 parallel to the first direction X is selected as the first point A0. And in the second region B, the midpoint of the edge L2 of the second electrode 103 parallel to the first direction X is selected as the second point B0.

[0098] Next, as Figure 7B As shown, using the transformation matrix, based on P T F i Q = 0, transform the first point A0 to the ideal second point B0. P(x) P ,y P ,1) represents the position data of the first point A0, Q(x Q ,y Q ,1) represents the position data of the ideal second point B0".

[0099] Since the misalignment between the first electrode 101 and the second electrode 103 exists only in the second direction Y, let the coordinate of the second point B0 in the second direction Y be y. R Find y Q With yR The difference is used to obtain the misalignment data between the first electrode 101 and the second electrode 103.

[0100] In some optional embodiments, the misalignment data between the first electrode 101 and the second electrode 103 is also used to mark the first point A0, the second point B0, and the fourth point D0 on a straight line with the same coordinates in the first direction X, so as to obtain the misalignment data between the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104.

[0101] like Figure 8A As shown, in the first region A, the midpoint of the edge L3 of the first diaphragm 102 extending beyond the first electrode 101 is selected as the third point C0 of the first diaphragm 102. And in the second region B, the midpoint of the edge L4 of the second diaphragm 104 extending beyond the second electrode 103 is selected as the fourth point D0 of the second diaphragm 104. Since the first point A0 and the third point C0 are both located on the first direction X, their coordinates are x... P On a straight line, the first point A0 and the third point C0 can only be misaligned in the second direction Y. Furthermore, since the second point B0 and the fourth point D0 are both located in the first direction X with coordinates x... Q Since it is on a straight line, the second point B0 and the fourth point D0 can only be misaligned in the second direction Y.

[0102] like Figure 8B As shown, the transformation matrix F will be used to transform the first point A0. i The ideal second point B0 is transformed and positioned on the same straight line as the first point B0 in the X direction. Then, based on the positional relationship between the first point A0 and the third point C0, the third point C0 is positioned on the same straight line as the ideal second point B0 in the X direction, thus becoming C0". Therefore, the first point A0, the second point B0, and the fourth point D0 can be positioned on the same straight line in the X direction, allowing for a direct and comprehensive observation of the degree of misalignment, and the determination of the misalignment data between the first electrode 101, the first diaphragm 102, the second electrode 103, and the second diaphragm 104.

[0103] Figure 9 This is a diagram illustrating the effect of a battery winding method according to an embodiment of this application. Figure 9 In the diagram, the horizontal axis represents the number of winding layers, and the vertical axis represents the actual distance. The solid line represents the actual misalignment distance between the first electrode 101 and the second electrode 103, while the dashed line represents the misalignment distance between the first electrode 101 and the second electrode 103 obtained through position data conversion processing using the aforementioned battery winding method. Figure 9 As shown, the difference between the solid line and the dashed line is less than 0.2 mm, which is much smaller than the required misalignment threshold of ±0.5 mm.

[0104] Therefore, the battery winding method of this application can eliminate errors caused by thickness variations due to the winding of the film composition, improve manufacturing accuracy, and obtain high-precision battery products.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery winding method, comprising: The winding step involves winding the film composition of the battery to be manufactured onto a winding shaft. The film composition includes a first electrode, a first separator, a second electrode, and a second separator stacked sequentially. In the imaging step, whenever the film composition is wound into a winding layer on the winding shaft, an image of the current winding layer is captured by a camera component set at a fixed position. The image of the current winding layer includes a first region and a second region arranged side by side in a first direction perpendicular to the winding shaft. The first region contains the first electrode sheet that has not yet been wound onto the winding shaft, and the second region contains the second electrode sheet that has been wound onto the winding shaft. The position data acquisition step involves acquiring position data of a first point in the first region and position data of a second point in the second region based on the captured image of the current winding layer. The first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction. The conversion step involves using a pre-set conversion matrix corresponding to the current winding layer to convert the position data of the first point based on the number of layers in the current winding layer, thereby obtaining the converted position data of the first point. and The judgment step involves calculating the misalignment data between the first electrode and the second electrode based on the converted position data of the first point and the position data of the second point, and determining whether the misalignment data is within a threshold range. If the misalignment data is within the threshold range, the winding step is returned to perform the winding of the next winding layer. If the misalignment data is not within the threshold range, an alarm is issued.

2. The battery winding method according to claim 1, wherein, The transformation matrix is ​​preset through the following steps: The first step is to select a reference battery and use the camera assembly to capture images of each winding layer of the reference battery. The images of each winding layer of the reference battery and the images of the current winding layer obtained in the shooting step also include the first region and the second region. The second step involves acquiring the location data of the first point in the first region and the location data of the second point in the second region, based on the image of each winding layer of the reference battery, similar to the location data acquisition step. The third step is to measure the actual misalignment distance between the first electrode and the second electrode in each winding layer, and to correct the second point based on the actual misalignment distance to obtain the corrected position data of the second point. The fourth step is to set a transformation matrix containing the parameters to be determined for each winding layer, and to establish a relationship between the position data of the first point and the corrected position data of the corrected second point based on the transformation matrix to be determined. and The fifth step involves selecting a corresponding number of points in the first region, including the first point, based on the number of parameters to be determined in the transformation matrix. Correspondingly, a corresponding number of points are selected in the second region, including the corrected second point. The selected points are then substituted into the relational expression to obtain the parameters to be determined in the transformation matrix, thus obtaining the transformation matrix.

3. The battery winding method according to claim 2, wherein, In the fourth step, the relation established based on the transformation matrix to be determined is: P n T F i ’Q n =0……(1), Among them, P n The image of the i-th winding layer of the reference battery includes the position data (x) of eight points selected within the first region from the first point. Pn ,y Pn ,1), n ​​is a natural number and 0≤n≤7, x Pn It is the coordinate in the first direction, y Pn It is the coordinate in the second direction perpendicular to the first direction, P n T For P n transpose, Q n In the image of the i-th winding layer of the reference cell, the corrected second point is included within the second region along with P. n The corresponding location data of the 8 selected points (x Qn ,y Qn ,1), n ​​is a natural number and 0≤n≤7, x Qn It is the coordinate in the first direction, y Qn It is the coordinate in the second direction. F i 'for It includes eight parameters to be determined, A11', A12', A13', A21', A22', A23', A31', and A32', representing that P will be used in the i-th winding layer. n Convert to Q n Relationship, i represents the number of winding layers. Based on the images obtained from photographing each of the winding layers of the reference battery, obtain P n and Q n , will P n and Q n Substitute the given relation P n T F i 'Q n =0, to obtain the F of each winding layer. i The parameter to be determined in '.

4. The battery winding method according to any one of claims 1 to 3, wherein, In the transformation step, the transformation matrix is ​​used to establish equation (2) to transform the position data of the first point into the transformed position data of the first point. P T F i Q=0……(2), Wherein, P is the position data (x, y) of the first point in the image of the current winding layer captured during the shooting step. P ,y P ,1),x P It is the coordinate in the first direction, y P In the image of the currently wound layer captured during the shooting step, the coordinates of the first point in a second direction perpendicular to the first direction are given by P. T Let P be the transpose of P. Q is the positional data (x) of the first point in the image of the current winding layer captured during the shooting step. Q ,y Q ,1),x Q In the image of the currently wound layer captured during the shooting step, the second point is located at the coordinates y in the first direction. Q These are the coordinates in the second direction that need to be determined. F i for It contains eight parameters A11, A12, A13, A21, A22, A23, A31, and A32, representing the relationship of converting P to Q in the i-th winding layer. i represents the number of winding layers. x P y P x Q and F i Substitute P T F i Q=0 to find y Q , In the image of the current winding layer captured during the shooting step, the coordinates in the second direction of the position data of the second point are taken and denoted as y. R , Find y Q With y R The difference is used as misalignment data between the first electrode and the second electrode.

5. The battery winding method according to any one of claims 1 to 3, wherein, In the image of the currently wound layer captured during the shooting step, a first diaphragm that has not yet been wound onto the winding shaft appears in the first region, and a second diaphragm that has been wound onto the winding shaft appears in the second region. The first diaphragm and the second diaphragm extend beyond the first electrode and the second electrode, respectively, in a second direction perpendicular to the first direction. The location data of the first point also includes the location data of the third point of the first diaphragm in the first region and the location data of the fourth point of the second diaphragm in the second region. The third point of the first diaphragm is, in the image of the current wound layer, the midpoint of the first diaphragm extending beyond the edge of the first electrode. The fourth point of the second diaphragm is, in the image of the current wound layer, the midpoint of the second diaphragm extending beyond the edge of the second electrode. Based on the misalignment data of the first electrode and the second electrode, the first point, the second point, the third point, and the fourth point are marked on a straight line with the same coordinates in the first direction X, and the misalignment data between the first electrode, the first diaphragm, the second electrode, and the second diaphragm can be obtained.

6. A battery winding system, comprising: A winding shaft for winding a film composition for a battery to be manufactured, the film composition comprising a first electrode, a first separator, a second electrode, and a second separator stacked sequentially; A camera assembly, spaced apart from the winding axis and used to capture images of each wound layer during the winding of the film composition to generate an image of the current wound layer, the image of the current wound layer including a first region and a second region side by side in a first direction perpendicular to the winding axis, the first region showing the first electrode sheet not yet wound on the winding axis, and the second region showing the second electrode sheet wound on the winding axis. and Control Department The control unit performs the following processing: Based on the captured image of the current winding layer, position data of a first point is obtained in the first region, and position data of a second point is obtained in the second region. The first point is the midpoint of the edge of the first electrode sheet parallel to the first direction, and the second point is the midpoint of the edge of the second electrode sheet parallel to the first direction. Based on the number of layers in the current winding layer, the position data of the first point is transformed using a pre-set transformation matrix corresponding to the current winding layer to obtain the transformed position data of the first point. Based on the converted position data of the first point and the position data of the second point, the misalignment data between the first electrode and the second electrode is calculated. It is determined whether the misalignment data is within a threshold range. When the misalignment data is within the threshold range, the winding axis is returned to wind the next winding layer. When the misalignment data is not within the threshold range, an alarm is issued.

7. A battery, wherein the battery winding method according to any one of claims 1 to 5 is used in the manufacturing process of the battery.

8. An electrical device comprising the battery of claim 7, the battery being used to provide electrical energy.

Images