Electrode material coating control method, device and equipment

Abstract

The embodiment of the invention provides an electrode material coating control method, device and equipment. The electrode material coating control method comprises the following steps: determining a winding radius corresponding to each to-be-coated area of a current collector; determining an area change coefficient of each to-be-coated area according to the winding radius, determining a target coating thickness based on the area change coefficient and a reference coating thickness of the electrode material layer, the target coating thickness being in linear positive correlation with the area change coefficient; and coating an electrode material layer on the corresponding to-be-coated area according to the target coating thickness. The target coating thickness is determined according to the winding radius, and the thicknesses of the electrode material layers of all the to-be-coated areas of the cylindrical pole group formed after the pole piece formed by coating the electrode material layers with the target coating thickness is wound are the same, so that the N / P ratios of all the areas of the cylindrical pole group can be ensured to be the same.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and specifically designs an electrode material coating control method, device and equipment. Background Art

[0002] In the related art, after the electrode material layer is coated on the current collector in a uniform coating manner to form a pole piece, the pole piece and the diaphragm are assembled according to a specific assembly process to form a pole group. In the case where the battery is a cylindrical battery, the coated pole piece and the diaphragm are wound and assembled using a winding process to form a cylindrical pole group. Since the electrode material layer on the coated pole piece is uniformly coated, in the process of winding and assembling to form a cylindrical pole group using a winding process, the coating of the electrode material layer on the concave surface of the coated pole piece is compressed, resulting in an increase in the surface thickness, and the coating of the electrode material layer on the convex surface of the coated pole piece is compressed, resulting in a decrease in the surface thickness. In addition, as the winding radius of the cylindrical pole group increases, the surface thickness of the concave electrode material layer coating gradually decreases, and the surface thickness of the convex electrode material layer gradually increases, so that the N / P ratio (the ratio of the battery negative electrode capacity to the positive electrode capacity) at each position of the pole group cross section presents a gradient change, and the different N / P ratios at each location of the pole group cross section have an adverse effect on the cycle life and safety of the finished battery cell. Summary of the invention

[0003] In order to solve the above technical problems, the embodiments of the present disclosure provide an electrode material coating control method, device, equipment and medium.

[0004] In a first aspect, an embodiment of the present disclosure provides an electrode material coating control method, comprising:

[0005] Determine the winding radius corresponding to each area to be coated of the current collector, the winding radius being the radius at the location of the area to be coated after the current collector is coated with an electrode material layer to form an electrode sheet and the electrode sheet is wound to form a cylindrical electrode group;

[0006] Determine the area variation coefficient of the area to be coated at each location according to the winding radius, and determine the target coating thickness based on the area variation coefficient and the reference coating thickness of the electrode material layer, wherein the area variation coefficient is the ratio of the area of ​​the area to be coated after winding to form the cylindrical electrode group to the area before winding to form the cylindrical electrode group, and the target coating thickness is linearly positively correlated with the area variation coefficient;

[0007] The electrode material layer is coated on the corresponding area to be coated according to the target coating thickness.

[0008] Optionally, the method further comprises: determining a surface layer type of each of the to-be-coated areas when winding to form a cylindrical pole group, the surface layer type being an inner concave surface or an outer convex surface;

[0009] Determining the area variation coefficient of each of the to-be-coated areas according to the winding radius includes:

[0010] The area variation coefficient is determined according to the winding radius and the surface layer type.

[0011] Optionally, determining the area variation coefficient according to the winding radius and the surface layer type includes:

[0012] When the surface layer type is an inner concave surface, the area variation coefficient is less than 1, and when the surface layer type is an outer convex surface, the area variation coefficient is greater than 1.

[0013] Optionally, determining the area variation coefficient according to the winding radius and the surface layer type includes:

[0014] In the case where the surface layer type is an inner concave surface, as the winding radius gradually increases, the area variation coefficient increases linearly from a first coefficient to a second coefficient, the first coefficient is between 0.95-0.99, and the second coefficient is between 0.995-0.999; and / or,

[0015] When the surface layer type is an outer convex surface, as the winding radius increases, the area variation coefficient decreases linearly from a third coefficient to a fourth coefficient, the third coefficient is between 1.01-1.05, and the fourth coefficient is between 1.001-1.005.

[0016] Optionally, the electrode material layer is a negative electrode material layer, and the surface layer type is an outer convex surface; the method further includes:

[0017] A first non-coating area is arranged outside the tail area of ​​the area to be coated, the tail area is the area of ​​the outer convex surface where the target coating thickness is the smallest, and the length of the first non-coating area is at least the outer circumference of the cylindrical pole group.

[0018] Optionally, the electrode material layer is a negative electrode material layer, and the surface layer type is a concave surface; the method further includes:

[0019] A second non-coating area is provided inside the head area of ​​the area to be coated, wherein the head area is the area in the inner concave surface where the target coating thickness is the smallest, and the length of the second non-coating area is at least equal to the circumference of the middle hole of the cylindrical pole group.

[0020] Optionally, the current collector is a continuous current collector that is not cut in the winding direction, and the continuous current collector is cut to form the electrode sheet after coating the electrode material layer;

[0021] The step of coating the electrode material layer on the corresponding area to be coated according to the target coating thickness comprises:

[0022] Periodically coating an electrode material layer on the to-be-coated area of ​​the continuous current collector according to the target coating thickness;

[0023] The method further includes: pausing coating between two coating cycles so as to form a cutting region on the continuous current collector, wherein the cutting region is used to cut off the coated continuous current collector to form the pole piece.

[0024] In a second aspect, an embodiment of the present disclosure provides an electrode material layer coating control device, comprising:

[0025] A radius determination unit, used to determine the winding radius corresponding to each to-be-coated area of ​​the current collector, wherein the winding radius is the radius of the to-be-coated area after the current collector is coated with an electrode material layer to form an electrode sheet and the electrode sheet is wound to form a cylindrical electrode group;

[0026] A coating thickness determination unit, for determining an area variation coefficient of each of the to-be-coated regions according to the winding radius, and determining a target coating thickness based on the area variation coefficient and a reference coating thickness of the electrode material layer, wherein the area variation coefficient is a ratio of an area of ​​the to-be-coated region after winding to form the cylindrical electrode group to an area of ​​the to-be-coated region before winding to form the cylindrical electrode group, and the target coating thickness is linearly positively correlated with the area variation coefficient;

[0027] A control unit is used to coat the electrode material layer in the corresponding area to be coated according to the target coating thickness.

[0028] In a third aspect, an embodiment of the present disclosure provides a control device, comprising a processor, a memory and a signal receiving device, wherein the memory is used to store a computer program, and the signal collector is used to collect signals; when the computer program is loaded by the processor, the processor controls the signal collector to collect signals to execute the electrode material coating control method as described above.

[0029] In a fourth aspect, an embodiment of the present disclosure provides a computer-readable storage medium, wherein the storage medium stores a computer program. When the computer program is executed by a processor, the processor implements the electrode material coating control method as described above.

[0030] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0031] Adopt the scheme provided by the example of the present disclosure, determine the winding radius corresponding to each area to be coated of the current collector, determine the area variation coefficient of the corresponding area to be coated according to the winding radius, determine the target coating thickness based on the variation coefficient and the reference coating thickness of the electrode material layer, and coat the electrode material layer in the area to be coated corresponding to the current collector according to the target coating thickness. Because the target coating thickness is determined according to the winding radius, and the electrode material layer thickness of each area to be coated of the cylindrical pole group formed after the pole piece coated with the electrode material layer at the target coating thickness is the same, the N / P ratio of each area of ​​the cylindrical pole group can be the same, thereby improving the cycle life and safety of the finished battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work, including:

[0034] Figure 1 is a flow chart of the electrode material coating control method provided by an embodiment of the present disclosure;

[0035] Figure 2 is a cross-sectional schematic diagram of a cylindrical pole group provided in some embodiments of the present disclosure;

[0036] Figure 3 is a cross-sectional view of a continuous current collector formed by coating in some embodiments of the present disclosure;

[0037] Figure 4 is a cross-sectional view of a continuous current collector formed by coating provided in some other embodiments of the present disclosure;

[0038] Figure 5 Is adopted Figure 4 A cross-sectional view of a pole piece formed by cutting a continuous current collector as shown;

[0039] Figure 6 is a cross-sectional schematic diagram of an electrode material layer coating control device provided in an embodiment of the present disclosure;

[0040] Figure 7 It is a structural diagram of a control device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0042] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the description below. It should be noted that the concepts of "first", "second", etc. mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0043] It should be noted that the modifications of "one" and "plurality" mentioned in the present disclosure are illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0044] In order to solve the problem in the related art that after the electrode material layer is coated on the current collector in a uniform coating manner to form a pole piece, the pole piece is then wound into a cylindrical pole group, which will cause different electrode material layers in different areas of the pole piece, thereby causing different N / P ratios in each area, the embodiment of the present disclosure provides a new electrode material coating control method. The new electrode material coating control method adaptively adjusts the target coating thickness of the electrode material layer coated in the previous coating process according to the size characteristics of the cylindrical pole group formed by winding the pole piece, ensuring that the thickness of the electrode material layer at each position of the cylindrical pole group formed by subsequent winding is the same, thereby making the N / P ratio of each area of ​​the cylindrical pole group the same.

[0045] Figure 1 : is a flow chart of the electrode material coating control method provided by the embodiment of the present disclosure. Figure 1 As shown, the electrode material coating control method provided by the example of the present disclosure includes S110-S130.

[0046] The electrode material coating control method provided in the embodiment of the present disclosure can be executed by a control device. The control device is a device used to control the operation of the coating device to achieve electrode material layer coating.

[0047] S110: Determine the winding radius corresponding to each area to be coated of the current collector.

[0048] The current collector is a conductive film material that carries the electrode material layer in the battery and can collect and output the current generated by the chemical reaction of the electrode material layer. In specific implementations, the current collector can be a copper current collector, an aluminum current collector, a stainless steel current collector, or a carbon current collector, which is not limited in the embodiments of the present disclosure.

[0049] In order to enable readers to clearly understand this embodiment, the following first briefly analyzes the production process of cylindrical batteries from current collectors to cylindrical pole groups. The production process of cylindrical batteries from current collectors to cylindrical pole groups includes the following 1 and 2.

[0050] 1. Preparation of electrode sheets. The preparation of electrode sheets includes the preparation of electrode material layer strips and the slitting of electrode material layer strips. The preparation of electrode material layer strips is to use a specific coating process to coat the electrode material layer (mostly electrode slurry) onto the current collector, and then undergo a drying process to allow the electrode material layer to adhere to the current collector to form the aforementioned electrode material layer strip. After obtaining the electrode material layer strip, the electrode material layer strip is then slit to obtain electrode sheets. For positive electrode materials and negative electrode materials, the aforementioned coating processes need to be used to form corresponding positive electrode sheets and negative electrode sheets, respectively.

[0051] 2. Winding of cylindrical electrode group. After obtaining the aforementioned positive electrode sheet and negative electrode sheet, use a winding machine to wind the positive electrode sheet, negative electrode sheet and separator to form a cylindrical electrode group. In the cylindrical electrode group, the separator isolates the positive electrode sheet and the negative electrode sheet to prevent the positive and negative electrodes from short-circuiting.

[0052] Figure 2 Schematic diagram of a cross section of a cylindrical pole group provided in some embodiments of the present disclosure. Figure 2 As shown, the positive electrode sheet 201 is formed by coating a positive electrode material 2011 on a current collector 2012, and the negative electrode sheet 202 is formed by coating a negative electrode material 2021 on a current collector 2012. A separator 203 is provided between the positive electrode sheet and the negative electrode sheet.

[0053] The winding radius of the area to be coated in the embodiment of the present disclosure refers to the radius of the area to be coated when the current collector is coated with the electrode material layer to form the electrode sheet and the electrode sheet is wound to form a cylindrical electrode group. For example, for the area to be coated C on the current collector 2012, the corresponding winding radius is Figure 2 For the area D to be coated on the current collector 2012, the corresponding winding radius is Figure 2 R2 in.

[0054] In a specific implementation, the control device can determine the winding radius corresponding to each area to be coated at the current collector in various ways.

[0055] In some embodiments, the control device stores cylindrical battery structure data. According to the cylindrical battery structure data, the length of the pole piece constituting the cylindrical battery and the winding radius corresponding to each area to be coated of the pole piece can be determined. The computing device can directly use the aforementioned winding radius as the winding radius of the current collector corresponding to the area to be coated.

[0056] In some other embodiments, the control device is configured with structural simulation software and with the size data of the winding needle (the winding needle is a winding shaft used for winding to form a cylindrical electrode group), the positive electrode sheet, the negative electrode sheet and the separator. After determining the size of the cylindrical electrode group to be processed, the control device can use the size data of the winding needle, the positive electrode sheet, the negative electrode sheet and the separator to perform winding simulation by means of structural simulation, determine the winding radius of each area to be coated of the positive electrode sheet and the negative electrode sheet after winding, and directly use the aforementioned winding radius as the winding radius of the area to be coated corresponding to the current collector.

[0057] S120: determining the area variation coefficient of each area to be coated according to the winding radius, and determining the target coating thickness based on the area variation coefficient and the reference coating thickness of the electrode material layer.

[0058] according to Figure 2 The structure of the cylindrical electrode group shown in the figure, in the process of forming the cylindrical electrode group by winding the electrode piece: (1) the concave surface area on the inner side of the electrode piece becomes smaller, so that the electrode material layer is compressed, thereby increasing the thickness of the coated electrode material layer; (2) the convex surface area on the outer side of the electrode piece increases, so that the electrode material layer is stretched, thereby reducing the thickness of the coated electrode material layer.

[0059] In order to ensure that the thickness of the electrode material layer in each area of ​​the pole piece formed by winding using the winding process is the same, it is necessary to perform advance compensation during the electrode material layer coating stage to achieve the following goals: (1) The electrode material layer coated on the concave surface of the inner side of the pole piece is compressed so that the coating thickness reaches the set value; (2) The electrode material layer coated on the convex surface of the outer side of the pole piece is stretched so that the coating thickness also reaches the set value.

[0060] In a specific implementation, advance compensation is performed during the electrode material layer coating stage to adjust the thickness of the electrode material layer coating in each area to be coated so that the thickness of the electrode material layer reaches a set value after the electrode material layer coating in the corresponding area is stretched or compressed, that is, the thickness of the electrode material layer in each area to be coated is the same.

[0061] To achieve the aforementioned objectives, in the disclosed embodiment, the corresponding area variation coefficient is determined according to the winding radius of the current collector area to be coated, and then the target coating thickness is determined according to the area variation coefficient and the reference coating thickness of the store material. The aforementioned area variation coefficient is the ratio of the area of ​​the area to be coated after winding to form a cylindrical pole group to the area before winding to form a cylindrical pole group. The aforementioned target coating thickness is linearly positively correlated with the area variation coefficient, that is, the larger the area variation coefficient, the larger the corresponding target coating thickness.

[0062] How to determine the target coating thickness of the corresponding area to be coated based on the winding radius will be analyzed in detail later. Here, it is only necessary to know that after the electrode material layer is coated according to the target coating thickness and the electrode piece is formed, and then the cylindrical electrode group is formed by winding the electrode piece, the thickness of the electrode material layer in each area to be coated can be the same.

[0063] S130: coating an electrode material layer at a corresponding area to be coated according to a target coating thickness.

[0064] After obtaining the target coating thickness corresponding to each area to be coated, the control device then controls the coating device to coat the electrode material layer in the corresponding area to be coated according to the designed coating thickness, so that the thickness of the electrode material layer coated in the corresponding area to be coated is the target coating thickness.

[0065] The electrode material coating control method provided by the embodiment of the present disclosure first determines the winding radius corresponding to each area to be coated of the current collector, determines the area variation coefficient of the area to be coated according to the winding radius, and then determines the target coating thickness of the corresponding area to be coated according to the area variation coefficient and the reference coating thickness of the electrode material layer, and coats the electrode material layer in the area to be coated corresponding to the current collector according to the target coating thickness. Because the target coating thickness is determined according to the winding radius, and the electrode material layer thickness of each area to be coated of the cylindrical electrode group formed after the pole piece coated with the electrode material layer at the target coating thickness is the same, it can ensure that the N / P ratio of each area of ​​the cylindrical electrode group is the same, thereby improving the cycle life and safety of the finished battery cell.

[0066] As analyzed above, when executing S120 , it is necessary to determine the area variation coefficient of each area to be coated according to the winding radius.

[0067] In some embodiments, two area variation coefficients may be determined based on a winding radius, the two area variation coefficients being an area variation coefficient corresponding to the inner concave surface and an area variation coefficient corresponding to the outer convex surface, wherein the area variation coefficient corresponding to the inner concave surface is smaller than the area variation coefficient corresponding to the outer convex surface.

[0068] In this case, the computing device needs to execute S140 before executing the aforementioned S120.

[0069] S140: Determine the surface layer type of each area to be coated when it is wound to form a cylindrical pole group.

[0070] In a specific implementation, the surface layer type of the area to be coated when it is wound to form a cylindrical pole group may be an inner concave surface or an inner convex surface, which needs to be determined according to actual conditions.

[0071] Correspondingly, the aforementioned S120 of determining the target coating thickness of the corresponding area to be coated according to the winding radius may specifically include the following S121.

[0072] S121: Determine the area variation coefficient according to the winding radius and the surface layer type of the area to be coated.

[0073] In a specific implementation, the specific steps of determining the area variation coefficient according to the winding radius and the surface type of the area to be coated are as follows: first, two area variation coefficients to be selected are determined according to the winding radius. Then, the calculation device determines the selected area variation coefficient from the two coating thicknesses to be selected according to the surface type of the area to be coated. In the case where the surface type of the area to be coated is an inner concave surface, the control device selects a smaller value as the area variation coefficient; and in the case where the surface type of the area to be coated is an outer convex surface, the control device selects a larger value as the area variation coefficient.

[0074] In some embodiments, the computing device stores a correlation between the winding radius and the area variation coefficient. After determining the winding radius, the control device uses the winding radius to perform data retrieval to determine the area variation coefficient to be selected.

[0075] After determining the area variation coefficient, the target coating thickness can be obtained by multiplying the area variation coefficient and the reference coating thickness.

[0076] According to the material winding deformation principle, combined with Figure 2 It can be seen that the area variation coefficients corresponding to different winding radii are not the same.

[0077] For example, for Figure 2 In the inner concave surface of the area to be coated C and the inner concave surface of the area to be coated D, because the deformation of the inner concave surface of the area to be coated C is greater than the deformation of the inner concave surface of the area to be coated D, the area change coefficient corresponding to the inner concave surface of the area to be coated C is smaller than the area change coefficient corresponding to the inner concave surface of the area to be coated D, so as to ensure that after winding, the thickness of the electrode material layer of the inner concave surface of the area to be coated C and the area to be coated D is the same. Similarly, because the deformation of the outer convex surface of the area to be coated C is greater than the deformation of the outer convex surface of the area to be coated D, the area change coefficient corresponding to the outer convex surface of the area to be coated C is greater than the area change coefficient corresponding to the outer convex surface of the area to be coated D.

[0078] In the disclosed embodiments, the control device may use various methods to determine the area variation coefficient corresponding to the area to be coated according to the winding radius.

[0079] In some embodiments, the control device stores data corresponding to various winding radii and area variation coefficients. After determining the winding radius, the computing device can determine the corresponding area variation coefficient through data retrieval.

[0080] In some other embodiments, the control device stores a function formula of the change of the winding radius and the change of the area change coefficient. After determining the winding radius, the computing device inputs the winding radius into the above function formula to determine the corresponding area change coefficient.

[0081] In some further embodiments, the control device stores simulation software, and the thickness change rate of the electrode material layer corresponding to each area to be coated can be determined by using the simulation software to perform winding simulation. The area change coefficient can be determined inversely based on the aforementioned area change rate.

[0082] After the area variation coefficient is determined, the value obtained by multiplying the area variation coefficient and the standard coating thickness is the target coating thickness corresponding to the area to be coated.

[0083] In some embodiments of the present disclosure, the size of the cylindrical pole group formed by winding the pole piece is determined, and the area variation coefficient corresponding to the corresponding area to be coated can be set within a specific range.

[0084] In some examples, when the surface layer type is an inner concave surface, as the winding radius gradually increases, the area variation coefficient of the inner concave surface increases linearly from the first coefficient to the second coefficient. When the cylindrical battery pole group is a pole group of a certain size, the first coefficient can be set between 0.95-0.99, and the second coefficient can be set between 0.995-0.999. If the diameter of the innermost winding area of ​​the cylindrical battery pole group is smaller, the first coefficient can be set smaller, for example, it can be set to 0.95; and if the outer diameter of the cylindrical pole group is larger, the second coefficient can be set larger, for example, it can be set to 0.999.

[0085] In some embodiments, when the surface layer type is an outer convex surface, as the winding radius component increases, the area variation coefficient of the outer convex surface decreases linearly from the third coefficient to the fourth coefficient. In the case where the cylindrical battery pole group is a pole group of a certain size, the third coefficient can be set between 1.01-1.05, and the fourth coefficient can be set between 1.001-1.005. If the diameter of the innermost winding area of ​​the cylindrical battery pole group is smaller, the third coefficient can be set larger, for example, it can be set to 1.05; and if the outer diameter of the cylindrical pole group is larger, the fourth coefficient can be set smaller, for example, it can be set to 1.001.

[0086] As mentioned above, in practical applications, the current collector is mostly a continuous current collector that is not cut in the winding direction. In order to improve the coating efficiency of the electrode material layer, in the prior art, after the electrode material layer is coated on the continuous current collector to form an electrode material layer strip, the current collector is cut along the axial direction to form a pole piece for assembling a cylindrical pole group. In this case, in order to continuously form an electrode material layer with a gradual thickness on the current collector, the control device executes S130 specifically as S131.

[0087] S131: Periodically coating an electrode material layer on the to-be-coated area of ​​the continuous current collector according to a target coating thickness.

[0088] The aforementioned periodic coating of the electrode material layer on the to-be-coated area of ​​the continuous current collector according to the target coating thickness means that after gradually completing the coating of the corresponding area of ​​a pole piece according to the target coating thickness of each to-be-coated area, the aforementioned steps are re-executed from the new to-be-coated area, and the cycle is repeated until the continuous current collector is completely coated.

[0089] In addition, according to the above analysis, after the continuous current collector is coated to form the electrode material layer strip, the electrode material layer strip needs to be cut to form the pole piece. In the embodiment of the present disclosure, in order to facilitate the cutting of the electrode material layer and avoid damaging the electrode material layer during the cutting process, while executing S131, the control device can also execute the following S150.

[0090] S150: Pause coating between two coating cycles to form a cut-off area on the continuous current collector, where the cut-off area is used to cut off the coated continuous current collector to form a pole piece.

[0091] Figure 3 is a cross-sectional view of a continuous current collector formed by coating in some embodiments of the present disclosure. Figure 3 As shown, the upper and lower surfaces of the continuous current collector 301 are coated with an electrode material layer 302, and a cut-off area 303 is provided in the continuously coated electrode material layer 302. No electrode material layer is coated outside the cut-off area 303. In the subsequent process, the continuous current collector can be cut from the cut-off area to form a pole piece of a specific length. The aforementioned specific length is determined according to the circumference of the cylindrical pole group and the various winding materials (including the positive pole piece, the negative pole piece and the separator) constituting the cylindrical pole group.

[0092] In actual production, cylindrical batteries that can be repeatedly charged and discharged are mostly lithium batteries, and their positive electrode material coatings are mostly high-cost coatings such as ternary lithium coatings and lithium iron phosphate coatings, while negative electrode materials are mostly low-cost coatings such as graphite coatings. Because the coating cost of the positive electrode material is higher than that of the negative electrode material, the positive electrode material is mostly saved as much as possible during the production process, and there are relatively few problems with the waste of negative electrode materials. In addition, in order to ensure the safety of cylindrical batteries during use, the negative electrode material is often set slightly more than the positive electrode material, so that the N / P ratio is greater than 1. In order to achieve the above goals, during the winding process of the cylindrical electrode group, the positive and negative electrode sheets are used as follows: Figure 2 The winding relationship shown in the figure shows that the innermost and outermost layers are both negative electrode material layers. Figure 2 When the winding relationship shown is used, if the negative electrode material layer is coated on the inner concave surface of the innermost circle and the outer convex surface of the outermost circle of the negative electrode sheet, the negative electrode material layer cannot be effectively utilized. In order to avoid the waste of negative electrode materials, in some embodiments, the inner concave surface of the innermost circle or the outer convex surface of the outermost circle of the negative electrode sheet is not coated with the electrode material layer. That is, while executing the aforementioned S130, the control device can also execute the following S160 or S170.

[0093] S160: When the electrode material layer is a negative electrode material layer and the surface layer type is an outer convex surface, a first non-coating area is set in the tail area of ​​the area to be coated.

[0094] In the disclosed embodiment, the tail area of ​​the outer convex surface to be coated is the area with the smallest thickness of the electrode material layer in the outer convex surface, and is also the area that is last attached to the separator when the negative electrode sheet is wound. Correspondingly, the first non-coated area is the outer convex surface area of ​​the outermost circle of the negative electrode sheet when the negative electrode sheet is wound to form a cylindrical electrode group.

[0095] In a specific implementation, the length of the first non-coated area needs to be determined based on the winding radius of the outermost layer of the cylindrical pole piece. It should be noted that due to the winding characteristics of the pole piece, the arc formed by the outermost layer of the cylindrical pole piece is not a circle. However, in practical applications, the outermost layer of the cylindrical pole piece can be simplified to a circle, and the length of the first non-coated area can be determined based on the radius of the outermost layer. In some other embodiments, the control device can determine the length of the first non-coated area by winding simulation.

[0096] S170: When the electrode material layer is a negative electrode material layer and the surface layer type is an inner concave surface, a second non-coating area is provided inside the head area of ​​the area to be coated.

[0097] In the disclosed embodiment, the head area of ​​the inner concave surface to be coated is the area with the smallest target coating thickness in the inner concave surface, that is, the area that first contacts the separator when the negative electrode sheet is wound. The corresponding second non-coating area is the inner concave surface area of ​​the innermost circle of the negative electrode sheet when the negative electrode sheet is wound to form a cylindrical electrode group.

[0098] In a specific implementation, the length of the second non-coated area needs to be determined according to the winding radius of the innermost layer of the cylindrical pole group. It should be noted that due to the winding characteristics of the pole piece, the arc formed by the innermost layer of the cylindrical pole piece is not a circle. However, in practical applications, the innermost layer can be simplified to a circle, and the length of the second non-coated area can be determined according to the radius of the circle. Of course, in some embodiments, the length of the second non-coated area can also be determined by winding simulation.

[0099] Figure 4 is a cross-sectional view of a continuous current collector formed by coating provided in some other embodiments of the present disclosure, Figure 5 Is adopted Figure 4 The cross-sectional view of the pole piece formed by cutting the continuous current collector is shown. Figure 4 The continuous current collector 401 shown is a current collector with negative electrode material layer 402 coated on both sides. The upper side of the continuous current collector 401 forms an inner concave surface after subsequent cutting to form a pole piece and winding, and the lower side forms an outer convex surface after subsequent cutting and winding. Combined with the previous description and the length of the uncoated area of ​​the upper and lower sides, it can be known that the uncoated area on the lower side is the first uncoated area 403, and the uncoated area on the upper side is the second uncoated area 404. Figure 4 The current collector shown is a continuous current collector. Figure 4 A cutting region is also provided at the end opposite regions of the first non-coated region 403 and the second non-coated region 404, so as to cut the continuous current collector coated with the electrode material layer into pole pieces by using the cutting region, so as to form a Figure 5 Pole piece shown.

[0100] In addition to providing the aforementioned electrode material coating control method, the embodiment of the present disclosure also provides an electrode material layer coating control device. Figure 6 Schematic diagram of a cross-sectional view of an electrode material layer coating control device provided in an embodiment of the present disclosure. Figure 6 As shown, the electrode material layer coating control device 600 provided in the embodiment of the present disclosure includes a radius determination unit 601 , a coating thickness determination unit 602 and a control unit 603 .

[0101] The radius determination unit 601 is used to determine the winding radius corresponding to each area to be coated on the current collector. The winding radius is the radius of the area to be coated after the current collector is coated with an electrode material layer to form a pole piece and the pole piece is wound to form a cylindrical pole group.

[0102] The coating thickness determination unit 602 is used to determine the area variation coefficient of each area to be coated according to the winding radius, and determine the target coating thickness based on the area variation coefficient and the baseline coating thickness of the electrode material layer. The area variation coefficient is the ratio of the area of ​​the area to be coated after winding to form a cylindrical pole group to the area before winding to form a cylindrical pole group. The target coating thickness is linearly positively correlated with the area variation coefficient.

[0103] The control unit 603 is used to coat the electrode material layer at the corresponding area to be coated according to the target coating thickness.

[0104] In some embodiments, the electrode material layer coating control device 600 further includes a surface layer type determination unit, which is used to determine the surface layer type of each area to be coated of the current collector when winding to form a cylindrical electrode group, and the surface layer type is an inner concave surface or an outer convex surface. Correspondingly, the coating thickness determination unit 602 determines the target coating thickness according to the winding radius and the surface layer type of the area to be coated.

[0105] In some embodiments, when the surface layer type is an inner concave surface, the area variation coefficient is less than 1, and when the surface layer type is an outer convex surface, the area variation coefficient is greater than 1.

[0106] In some embodiments, when the surface layer type is an inner concave surface, as the winding radius gradually increases, the coefficient determination subunit causes the area variation coefficient to increase linearly from a first coefficient to a second coefficient, the first coefficient is between 0.95-0.99, and the second coefficient is between 0.995-0.999;

[0107] When the surface layer type is an outer convex surface, as the winding radius increases, the coefficient determination subunit causes the area variation coefficient to linearly decrease from the third coefficient to the fourth coefficient, the third coefficient is between 1.01-1.05, and the fourth coefficient is between 1.001-1.005.

[0108] In some embodiments, the electrode material layer is a negative electrode material layer, and the surface layer type is an outer convex surface; the control unit 603 is also used to set a first non-coating area outside the tail area of ​​the area to be coated, and the tail area is the area with the smallest target coating thickness in the outer convex surface, and the length of the first non-coating area is at least the outer circumference of the cylindrical pole group.

[0109] In some embodiments, the electrode material layer is a negative electrode material layer, and the surface layer type is a concave surface; the control unit 603 is also used to set a second non-coating area inside the head area of ​​the area to be coated, the area in the concave surface in the head area where the target coating thickness is the smallest, and the length of the second non-coating area is at least equal to the circumference of the middle hole of the cylindrical pole group.

[0110] In some embodiments, the current collector is a continuous current collector that is not cut in the winding direction, and the continuous current collector is cut to form a pole piece after coating the electrode material layer. Correspondingly, the control unit 603 periodically coats the electrode material layer on the to-be-coated area of ​​the continuous current collector according to the target coating thickness, and suspends the coating between two coating cycles, so that a cut-off area is formed on the continuous current collector, and the cut-off area is used to cut the coated continuous current collector to form a pole piece.

[0111] An embodiment of the present disclosure also provides a control device, which includes a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the test method of the screen projection function of any of the above embodiments can be implemented.

[0112] Figure 7 Schematic diagram of the structure of the control device provided by the embodiment of the present disclosure. Figure 7 , which shows a structural schematic diagram of a control device 700 suitable for implementing the embodiments of the present disclosure. Figure 7 The control device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0113] like Figure 7 As shown, the control device 700 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory ROM 702 or a program loaded from a storage device 708 to a random access memory RAM 703. In the RAM 703, various programs and data required for the operation of the control device 700 are also stored. The processing device 701, the ROM 702, and the RAM 703 are connected to each other via a bus 704. An input / output I / O interface 705 is also connected to the bus 704.

[0114] Typically, the following devices may be connected to the I / O interface 705: input devices 706 including, for example, a touch screen, a touch pad, a camera, a microphone, an accelerometer, a gyroscope, etc.; output devices 707 including, for example, a liquid crystal display 204 (LCD), a speaker, a vibrator, etc.; storage devices 708 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 709. The communication devices 709 may allow the control device 700 to communicate with other devices wirelessly or by wire to exchange data. Although Figure 7 The control device 700 is shown with various devices, but it should be understood that it is not required to implement or have all the devices shown. More or fewer devices may be implemented or have instead.

[0115] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device 709, or installed from a storage device 708, or installed from a ROM 702. When the computer program is executed by the processing device 701, the above-mentioned functions defined in the method of the embodiment of the present disclosure are executed.

[0116] It should be noted that the computer-readable medium disclosed above may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in combination with an instruction execution system, device or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which a computer-readable program code is carried. This propagated data signal may take a variety of forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0117] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (Hypertext Transfer Protocol), and may be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an ad hoc peer-to-peer network), as well as any currently known or future developed network.

[0118] The computer-readable medium may be included in the control device, or may exist independently without being assembled into the control device.

[0119] The above-mentioned computer-readable medium carries one or more programs. When the above-mentioned one or more programs are executed by the control device, the control device: determines the winding radius corresponding to each to-be-coated area of ​​the current collector, the winding radius is the radius at the location of the to-be-coated area after the current collector is coated with an electrode material layer to form a pole piece and the pole piece is wound to form a cylindrical pole group; determines the area variation coefficient of each to-be-coated area according to the winding radius, and determines the target coating thickness based on the area variation coefficient and the reference coating thickness of the electrode material layer, the area variation coefficient is the ratio of the area of ​​the to-be-coated area after the cylindrical pole group is wound to the area before the cylindrical pole group is wound, and the target coating thickness is linearly positively correlated with the area variation coefficient; and coats the electrode material layer in the corresponding to-be-coated area according to the target coating thickness.

[0120] Computer program code for performing the operations of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the tester computer, partially on the tester computer, as a separate software package, partially on the tester computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the tester computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0121] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present disclosure. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated system based on hardware that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0122] The units involved in the embodiments described in the present disclosure may be implemented by software or hardware, wherein the name of a unit does not, in some cases, limit the unit itself.

[0123] The functions described above herein may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), and the like.

[0124] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection according to one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0125] The embodiments of the present disclosure also provide a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the method of any of the above method embodiments can be implemented. The execution method and beneficial effects are similar and will not be repeated here.

[0126] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0127] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling electrode material coating, characterized in that: include: Determine the winding radius corresponding to each area to be coated of the current collector, the winding radius being the radius at the location of the area to be coated after the current collector is coated with an electrode material layer to form an electrode sheet and the electrode sheet is wound to form a cylindrical electrode group; Determine the area variation coefficient of the area to be coated at each location according to the winding radius, and determine the target coating thickness based on the area variation coefficient and the reference coating thickness of the electrode material layer, wherein the area variation coefficient is the ratio of the area of ​​the area to be coated after winding to form the cylindrical electrode group to the area before winding to form the cylindrical electrode group, and the target coating thickness is linearly positively correlated with the area variation coefficient; The electrode material layer is coated on the corresponding area to be coated according to the target coating thickness.

2. The method according to claim 1, characterized in that The method further comprises: Determining the surface layer type of each of the to-be-coated areas when winding to form a cylindrical pole group, the surface layer type being an inner concave surface or an outer convex surface; Determining the area variation coefficient of each of the to-be-coated areas according to the winding radius includes: The area variation coefficient is determined according to the winding radius and the surface layer type.

3. The method according to claim 2, characterized in that The determining the area variation coefficient according to the winding radius and the surface layer type includes: When the surface layer type is an inner concave surface, the area variation coefficient is less than 1, and / or, when the surface layer type is an outer convex surface, the area variation coefficient is greater than 1.

4. The method according to claim 3, characterized in that: The determining the area variation coefficient according to the winding radius and the surface layer type includes: In the case where the surface layer type is an inner concave surface, as the winding radius gradually increases, the area variation coefficient increases linearly from a first coefficient to a second coefficient, the first coefficient is between 0.95-0.99, and the second coefficient is between 0.995-0.999; and / or, When the surface layer type is an outer convex surface, as the winding radius increases, the area variation coefficient decreases linearly from a third coefficient to a fourth coefficient, the third coefficient is between 1.01-1.05, and the fourth coefficient is between 1.001-1.

005.

5. The method according to claim 2, characterized in that: The electrode material layer is a negative electrode material layer, and the surface layer type is an outer convex surface; the method further comprises: A first non-coating area is arranged outside the tail area of ​​the area to be coated, the tail area is the area of ​​the outer convex surface where the target coating thickness is the smallest, and the length of the first non-coating area is at least the outer circumference of the cylindrical pole group.

6. The method according to claim 2, characterized in that The electrode material layer is a negative electrode material layer, and the surface layer type is an inner concave surface; the method further includes: A second non-coating area is provided inside the head area of ​​the area to be coated, wherein the head area is the area in the inner concave surface where the target coating thickness is the smallest, and the length of the second non-coating area is at least equal to the circumference of the middle hole of the cylindrical pole group.

7. The method according to any one of claims 1 to 6, characterized in that: The current collector is a continuous current collector that is not cut in the winding direction, and the continuous current collector is cut to form the electrode sheet after coating the electrode material layer; The step of coating the electrode material layer on the corresponding area to be coated according to the target coating thickness comprises: Periodically coating an electrode material layer on the to-be-coated area of ​​the continuous current collector according to the target coating thickness; The method further includes: pausing coating between two coating cycles so as to form a cutting region on the continuous current collector, wherein the cutting region is used to cut off the coated continuous current collector to form the pole piece.

8. An electrode material coating control device, characterized in that: include: A radius determination unit, used to determine the winding radius corresponding to each to-be-coated area of ​​the current collector, wherein the winding radius is the radius of the to-be-coated area after the current collector is coated with an electrode material layer to form an electrode sheet and the electrode sheet is wound to form a cylindrical electrode group; A coating thickness determination unit, used to determine the area variation coefficient of each area to be coated according to the winding radius, and determine the target coating thickness based on the area variation coefficient and the reference coating thickness of the electrode material layer, wherein the area variation coefficient is the ratio of the area of ​​the area to be coated after being wound to form the cylindrical electrode group to the area before being wound to form the cylindrical electrode group, and the target coating thickness is linearly positively correlated with the area variation coefficient; A control unit is used to coat the electrode material layer in the corresponding area to be coated according to the target coating thickness.

9. A control device, characterized in that: It includes a processor, a memory and a signal receiving device, wherein the memory is used to store computer programs, and the signal collector is used to collect signals; When the computer program is loaded by the processor, the processor controls the signal collector to collect signals to execute the electrode material coating control method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the processor implements the electrode material coating control method as described in any one of claims 1 to 7.

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