Method and apparatus for determining boundary of thinned coating region of electrode sheet, electronic device, and medium

Abstract

The present application provides a method and apparatus for determining the boundary of a thinned coating region of an electrode sheet, an electronic device, and a medium. The method comprises the steps: obtaining an initial contour curve from a contour curve set of an initial thinned coating region of a target electrode sheet; on the basis of the material region surface density of a material region in the target electrode sheet and the initial contour curve, determining a corresponding initial positive and negative electrode capacity ratio; and if the initial positive and negative electrode capacity ratio meets a preset positive and negative electrode capacity ratio, determining that the initial contour curve is the boundary of the initial thinned coating region.

Description

Method and device for determining boundary of coating thinning area of pole piece, electronic equipment and medium

[0001] The present application claims priority to the Chinese patent application No. 202410410696.9, filed on April 7, 2024, to the Chinese Patent Office, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a method and device for determining the boundary of a coating thinning area of a pole piece, an electronic equipment and a medium. BACKGROUND

[0003] In the production and processing process of power batteries, a series of treatments are usually required for the substrate, and the processing and treatment process of the substrate usually consists of coating, drying and other steps. Coating is a basic process in the manufacturing process of lithium ion batteries, which involves coating slurry on foil to obtain positive and negative pole pieces of lithium ion batteries. However, when using coating to make battery pole pieces, in order to avoid abnormalities in the edges of the pole pieces, thinning treatment needs to be performed on the edges of the pole pieces, and the area in the pole piece where the thinning treatment is performed is the coating thinning area. If the surface tension of the slurry and other factors cause thick edges and drum edges during the coating process, it will directly affect the quality of the film after drying and the subsequent processing of the substrate. SUMMARY

[0004] In related technologies, the boundary of the coating thinning area of the pole piece is determined directly based on experience values, which cannot ensure the accuracy of the boundary of the coating thinning area of the pole piece, and there may be situations where the coating edge thinning area of the pole piece is insufficient or excessive. This way makes the boundary design of the coating thinning area of the pole piece unreasonable, which affects the lithium precipitation of the pole edge of the battery cell and the insufficient lithium intercalation, and is not conducive to improving the electrical performance and safety performance of the battery cell.

[0005] In a first aspect, embodiments of the present application provide a method for determining the boundary of a coating thinning area of a pole piece, the method comprising:

[0006] From a set of profile curves corresponding to the initial coating thinning area of the target pole piece, at least one profile curve constituting a thinning area topography profile is obtained as an initial profile curve, and the set of profile curves includes a plurality of profile curves constituting a plurality of thinning area topography profiles;

[0007] determining an initial positive and negative capacity ratio corresponding to the target pole piece according to the area density of the target pole piece and the initial profile curve;

[0008] If the initial positive and negative capacity ratio meets a preset positive and negative capacity ratio, the initial profile curve is determined as the boundary of the initial coating thinning area.

[0009] In a second aspect, embodiments of the present application provide a device for determining a boundary of a coating thinning area of a pole piece, the device comprising:

[0010] an acquisition module configured to acquire, from a set of profile curves corresponding to the initial coating thinning area of the target pole piece, at least one profile curve constituting a thinning area topography profile as an initial profile curve, the set of profile curves comprising a plurality of profile curves constituting a plurality of thinning area topography profiles;

[0011] a first determination module configured to determine an initial positive-negative electrode capacity ratio corresponding to the target pole piece according to a face density of a material area corresponding to the target pole piece and the initial profile curve;

[0012] a second determination module configured to determine the initial profile curve as the boundary of the initial coating thinning area if the initial positive-negative electrode capacity ratio meets a preset positive-negative electrode capacity ratio.

[0013] In a third aspect, embodiments of the present application provide an electronic device, the electronic device comprising:

[0014] one or more processors;

[0015] a memory; and

[0016] one or more application programs, wherein the one or more application programs are stored in the memory and configured to be executed by the processor to implement the steps in the method for determining the boundary of the coating thinning area of the pole piece according to any one of the first aspect.

[0017] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to execute the steps in the method for determining the boundary of the coating thinning area of the pole piece according to any one of the first aspect.

[0018] In a fifth aspect, the present application further provides a computer program product comprising computer programs / instructions, which, when executed by a processor, are used to execute the steps in the method for determining the boundary of the coating thinning area of the pole piece according to any one of the first aspect. Advantages

[0019] Advantages of embodiments of the present application:

[0020] In the embodiment of the present application, by acquiring an initial profile curve corresponding to the initial coating thinning area of the pole piece, determining the initial positive and negative electrode capacity ratio of the target pole piece according to the initial profile curve, when the initial positive and negative electrode capacity ratio meets the condition, taking the initial profile curve as the boundary of the coating thinning area of the pole piece. Since the initial profile curve quantitatively represents the profile of the thinning area, and the determination of the boundary of the coating thinning area is based on the initial profile curve, the accuracy of the boundary design of the coating thinning area is ensured, and the rationality of the boundary design of the coating thinning area is improved by using the positive and negative electrode capacity ratio for rationality verification, thereby improving the electrical performance and safety performance of the battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 is a flowchart of some embodiments of a method for determining the boundary of the coating thinning area of the pole piece according to an embodiment of the present application;

[0022] FIG. 2 is a schematic diagram of a target pole piece according to an embodiment of the present application;

[0023] FIG. 3 is a schematic diagram of a set of profile curves according to an embodiment of the present application;

[0024] FIG. 4 is a flowchart of some embodiments of a method for determining the boundary of the coating thinning area of the pole piece according to an embodiment of the present application;

[0025] FIG. 5 is a flowchart of some embodiments of a method for determining the boundary of the coating thinning area of the pole piece according to an embodiment of the present application;

[0026] FIG. 6 is a flowchart of some embodiments of a method for determining the boundary of the coating thinning area of the pole piece according to an embodiment of the present application;

[0027] FIG. 7 is a schematic diagram of some embodiments of a device for determining the boundary of the coating thinning area of the pole piece according to an embodiment of the present application;

[0028] FIG. 8 is a schematic diagram of some embodiments of an electronic device according to an embodiment of the present application. Embodiments of the present application

[0029] At present, most of the standards of the coating thinning area of the pole piece are set by experience value, and the standards are formulated by combining the actual verification results of the gasket supplier of the pole piece of the battery cell. Usually, the width and thickness difference of the starting point and the end point of the coating thinning area are taken as the boundary of the coating thinthing area, and the edge of the pole piece is ensured to be not thick (the thick edge can be understood as the edge thickness of the pole piece being greater than the material area), not powdering (the edge thinning transition is smooth), and no process abnormality problem, etc. The determination method of the boundary of the coating thinning area leads to that the design standard of the coating thinning area is too wide and the rationality of the boundary design of the coating thinning area cannot be effectively verified, and the situation of insufficient thinning or excessive thinning often occurs in the production process. Therefore, the application provides a boundary determination method, device, electronic equipment and computer storable medium for a pole piece coating thinning area, so as to improve the rationality of the boundary design of the coating thinning area and improve the electrical performance and safety performance of the battery cell.

[0030] As shown in FIG. 1, it is an embodiment flow diagram of a boundary determination method for a pole piece coating thinning area in the application. The boundary determination method for the pole piece coating thinning area can be executed by a battery pole piece bad coating screening and judging device. The boundary determination device for the pole piece coating thinning area can be integrated in an electronic equipment, and the boundary determination device for the pole piece coating thinning area can be realized by software and / or hardware. The boundary determination method for the pole piece coating thinning area comprises the following steps:

[0031] 101. From the profile curve set corresponding to the initial coating thinning area of the target pole piece, at least one profile curve constituting a thinning area topography profile is obtained as an initial profile curve. The profile curve set comprises a plurality of profile curves constituting a plurality of thinning area topography profiles.

[0032] Wherein, the target pole piece can be a lithium ion battery cell pole piece, wherein the battery cell pole piece is composed of a positive pole piece and a negative pole piece. The target pole piece includes a coating thinning area and a material area, that is, the positive pole piece and the negative pole piece both include a corresponding coating thinning area and a material area. The coating thinning area refers to the area subjected to coating process and thinning treatment. The initial coating thinning area in the embodiment is a pole piece edge qualified thinning area, which can be determined by detecting the edge of a given original thinning area, or a data sample library of the pole piece edge qualified thinning area can be obtained, and the data corresponding to the original thinning area is compared with the data sample library, so as to screen out the pole piece edge qualified thinning area as the initial coating thinning area.

[0033] The initial profile curve is a curve corresponding to the profile of the initial coating thinning area, that is, the boundary of the initial coating thinning area. As shown in FIG. 2, it is a schematic diagram of a target pole piece, A1 is a material area, and A2 is a thinning area profile. The initial profile curve is at least one profile curve constituting a thinning area profile, wherein the profile curve constituting a thinning area profile can be one, two or more, as long as it can constitute a thinning area profile. For the case of one profile curve, a profile curve can be pre-selected, and the selected profile curve and one profile curve in the profile curve set constitute a thinning area profile. As preferred in this embodiment, the two profile curves with the largest enclosed area can be selected from the multiple profile curves constituting multiple thinning area profiles as the initial profile curve, wherein the two profile curves include an initial upper limit profile curve and an initial lower limit profile curve, and the area between the initial upper limit profile curve and the lower limit profile curve is larger than the area between any two profile curves constituting a thinning area profile. In this way, the range of the boundary of the initial coating thinning area determined first can be maximized to improve the efficiency of the boundary of the initial coating thinning area. As shown in FIG. 3, it is a schematic diagram of a profile curve set, L1, L2, L3 and L4 are profile curves, wherein L1 and L4 enclose the largest area, L1 is the initial upper limit profile curve, and L4 is the initial lower limit profile curve.

[0034] Specifically, before step 101, it further includes: determining the initial coating thinning area of the target pole piece; performing a scanning test on the initial coating thinning area and the material area in the target pole piece to measure multiple sets of widths of the initial coating thinning area and thicknesses of the material area; and performing curve fitting based on the multiple sets of widths of the initial coating thinning area and thicknesses of the material area, with the width as the independent variable and the thickness as the dependent variable, to obtain a profile curve set.

[0035] Specifically, the original thinning area of the target pole piece can be obtained according to artificial experience, and then the edges of the original thinning area are detected to screen out the original thinning area with a qualified pole piece edge as the initial coating thinning area. Alternatively, the initial coating thinning area of the target pole piece can be pre-stored in the memory of the terminal to directly obtain the initial coating thinning area. Then, the material area and the initial coating thinning area of the target pole piece are transversely scanned at a certain speed by an online detection device such as a laser profile tester, each data point is spaced apart by 0.5 mm to 1 mm, the thickness data of the pole piece along the width direction is measured, that is, the width (denoted by b) of the initial coating thinning area and the thickness (denoted by h) of the material area are obtained, and then curve fitting is performed with the width b as the independent variable and the thickness h as the dependent variable to obtain multiple profile curves b = h(x). At least one profile curve constituting a thinning area profile in the profile curve set is taken as the initial profile curve.

[0036] Understandably, in the embodiment, the profile of the initial coating thinning area is quantitatively characterized by measuring the continuous width data of the initial coating thinning area with the edge of the pole piece qualified and the thickness data of the material area, the problem of inaccurate profile of the initial coating thinning area caused by empirical value in the traditional scheme is overcome, and the profile of the initial coating thinning area is characterized in principle and data at the same time, the initial profile curve is determined by continuous function fitting, the accuracy of the initial profile curve is improved, so as to improve the accuracy of the boundary of the coating thinning area of the target pole piece based on the initial profile curve.

[0037] 102. Determine the initial positive and negative capacity ratio value of the target pole piece according to the material area surface density corresponding to the material area in the target pole piece and the initial profile curve.

[0038] Wherein, the positive and negative capacity ratio value (cell Balance, CB value), also known as N / P (Negative / Positive), is the ratio of the negative active material capacity to the positive active material capacity under the same condition in the same stage.

[0039] The area in the target pole piece without the initial coating thinning area is the material area, which is divided into positive material area and negative material area, that is, the material area in the positive pole piece is the positive material area, and the material area in the negative pole piece is the negative material area. The material area surface density, active material gram capacity, and active material content percentage corresponding to the positive material area, and the material area surface density, active material gram capacity, and active material content percentage corresponding to the negative material area are determined in advance in the battery preparation process, and are known quantities.

[0040] In one specific embodiment, the calculation formula of the initial positive and negative capacity ratio value, that is, CB, is:

[0041] ; (1)

[0042] In formula (1), represents the negative surface density of the negative pole piece, represents the active material gram capacity of the negative material area, represents the active material content percentage of the negative material area, represents the positive surface density of the positive pole piece, represents the active material gram capacity of the positive material area, represents the active material content percentage of the positive material area.

[0043] Since the negative face density of the negative pole piece can be calculated by the material area face density of the negative material area and the initial profile curve, and the positive face density of the positive pole piece can be calculated by the material area face density of the positive material area and the initial profile curve, in this embodiment, the initial positive and negative capacity ratio of the target pole piece is determined according to the material area face density and the initial profile curve of the positive material area and the negative material area.

[0044] Specifically, step 102 comprises: determining the face density of the target pole piece according to the material area face density and the initial profile curve of the material area; and determining the initial positive and negative capacity ratio according to the face density of the target pole piece.

[0045] Specifically, the face density of the target pole piece is determined according to the material area face density and the initial profile curve of the material area, and after the face density of the target pole piece is determined, the initial positive and negative capacity ratio is determined according to the face density of the target pole piece.

[0046] Specifically, as shown in FIG. 4, the target pole piece comprises a positive pole piece and a negative pole piece, the material area in the target pole piece without the initial coating thinning area comprises a positive material area in the positive pole piece and a negative material area in the negative pole piece, the material area face density comprises the material area face density corresponding to the positive material area and the negative material area respectively; and step 102 comprises 102A-102B.

[0047] 102A, determining the positive face density corresponding to the positive pole piece according to the material area face density corresponding to the positive material area and the initial profile curve, and determining the negative face density corresponding to the negative pole piece according to the material area face density corresponding to the negative material area and the initial profile curve.

[0048] Wherein, the negative face density is the sum of the material area face density corresponding to the negative material area and the face density corresponding to the negative thinning area, and the positive face density is the sum of the material area face density corresponding to the positive material area and the face density corresponding to the positive thinning area.

[0049] In one specific embodiment, the calculation formula of the positive face density and the negative face density is as follows:

[0050] ;(2)

[0051] ;(3)

[0052] In formula (2) and (3), represents the material area face density corresponding to the negative material area, represents the face density corresponding to the negative thinning area, represents the material area face density corresponding to the positive material area, represents the face density corresponding to the positive thinning area.

[0053] Since the area density corresponding to the negative electrode thinning area can be calculated by the initial profile curve and the area density of the negative electrode area, and the area density corresponding to the positive electrode thinning area can be calculated by the initial profile curve and the area density of the positive electrode area, the positive electrode area density and the negative electrode area density can be determined according to the area density of the positive electrode area and the negative electrode area corresponding to each other, and the initial profile curve.

[0054] Specifically, as shown in FIG. 5, the initial coating thinning area includes a positive electrode thinning area corresponding to the positive electrode sheet and a negative electrode thinning area corresponding to the negative electrode sheet; step 102A includes 102A1-102A4.

[0055] 102A1, determine the positive electrode thinning area density corresponding to the positive electrode thinning area based on the area density of the positive electrode area corresponding to the area and the initial profile curve.

[0056] Specifically, the area density of the initial coating thinning area can be calculated by the known area density of the area, and the ratio of the surface area to the cross-sectional area of the initial coating thinning area can be converted according to the coating film height, the coating film length, the width of the initial coating thinning area and the corresponding proportional relationship of the area thickness.

[0057] In formula (4), represents the length of the target sheet, b represents the width of the initial coating thinning area, represents the thickness of the area, represents the area density of the initial coating thinning area, represents the area density of the area, represents the density of the target sheet, represents the cross-sectional area of the initial coating thinning area, represents the cross-sectional area of the area, represents the surface area of the initial coating thinning area, , represents the surface area of the area, represents the length of the target sheet, and b represents the width of the initial coating thinning area.

[0058] Substitute into the above formula (4) for transformation processing, it can be known that .

[0059] The initial coating thinning area includes the positive electrode thinning area and the negative electrode thinning area. For the positive electrode thinning area density, the above formula can be replaced by , can be replaced by , can be replaced by​ , for example: ; wherein, represents the width of the positive electrode thinning area, represents the thickness of the positive electrode material area, represents the area density of the positive electrode thinning area, represents the material area density of the positive electrode material area, represents the cross-sectional area of the positive electrode thinning area.

[0060] Since the cross-sectional area of the initial coating thinning area can be calculated according to the initial profile function, based on the material area density corresponding to the positive electrode material area and the initial profile curve, the positive electrode thinning area density corresponding to the positive electrode thinning area can be determined, and based on the material area density corresponding to the negative electrode material area and the initial profile curve, the positive electrode thinning area density corresponding to the negative electrode thinning area can be determined.

[0061] Specifically, the initial profile curve includes a negative electrode profile curve corresponding to the negative electrode thinning area; based on the material area density corresponding to the negative electrode material area and the initial profile curve, the negative electrode thinning area density corresponding to the negative electrode thinning area is determined, including: determining the negative electrode cross-sectional area corresponding to the negative electrode thinning area based on the negative electrode profile curve; determining the negative electrode thinning area density based on the negative electrode profile curve, the negative electrode cross-sectional area, and the material area density corresponding to the negative electrode material area.

[0062] Specifically, for the negative electrode thinning area density, in the formula is replaced by , is replaced by , is replaced by , for example: ; wherein, represents the width of the negative electrode thinning area, represents the thickness of the negative electrode material area, represents the area density of the negative electrode thinning area, represents the material area density of the negative electrode material area, represents the cross-sectional area of the negative electrode thinning area.

[0063] Specifically, as shown in FIG. 6, the initial profile curve includes a positive electrode profile curve corresponding to the positive electrode thinning area, step 102A1, including 102A11-102A12.

[0064] 102A11, determining the positive electrode cross-sectional area corresponding to the positive electrode thinning area based on the positive electrode profile curve.

[0065] Specifically, step 102A11 includes: integrating the positive electrode profile curve to obtain the positive electrode cross-sectional area.

[0066] Correspondingly, the initial profile curve further comprises a negative electrode profile curve corresponding to the negative electrode thinning area.

[0067] wherein the initial profile curve comprises a positive electrode profile curve corresponding to the positive electrode thinning area and a negative electrode profile curve corresponding to the negative electrode thinning area .

[0068] Specifically, the cross-sectional area of the initial coating thinning area is the integral of the initial profile curve , that is . For the positive electrode cross-sectional area, it can be calculated by the formula .

[0069] Correspondingly, for the negative electrode cross-sectional area, it can be calculated by the formula .

[0070] 102A12, determining the positive electrode thinning area density based on the positive electrode profile curve, the positive electrode cross-sectional area, and the material area density corresponding to the positive electrode material area.

[0071] Specifically, step 102A12 comprises: obtaining the interval endpoint values corresponding to the independent variables in the positive electrode profile curve; determining the interval endpoint values corresponding to the dependent variables in the positive electrode profile curve based on the interval endpoint values corresponding to the independent variables in the positive electrode profile curve; determining the width of the initial coating thinning area and the thickness of the positive electrode material area based on the interval endpoint values corresponding to the independent variables and dependent variables in the positive electrode profile curve, to obtain the width value corresponding to the positive electrode coating thinning area and the thickness value corresponding to the positive electrode material area; and determining the positive electrode thinning area density based on the product of the thickness value corresponding to the positive electrode coating thinning area and the width value corresponding to the positive electrode material area, the material area density corresponding to the positive electrode material area, and the positive electrode cross-sectional area.

[0072] Specifically, based on the interval endpoint values corresponding to the independent variables in the positive electrode profile curve, such as [0, ], the is substituted into the positive electrode profile curve to calculate the corresponding dependent variable, such as , so as to obtain the width of the positive electrode thinning area and the thickness of the positive electrode material area. Substituting the positive electrode cross-sectional area into the calculation formula of the positive electrode thinning area density , the positive electrode thinning area density can be calculated.

[0073] Specifically, the surface density of the negative electrode thinning area is determined based on the negative electrode contour curve, the negative electrode cross-sectional area, and the material area surface density corresponding to the negative electrode material area, including: obtaining the interval endpoint value corresponding to the independent variable in the negative electrode contour curve; determining the interval endpoint value corresponding to the dependent variable in the negative electrode contour curve based on the interval endpoint value corresponding to the independent variable in the negative electrode contour curve; determining the width of the negative electrode thinning area and the thickness of the negative electrode material area based on the interval endpoint values ​​corresponding to the independent variable and the dependent variable in the negative electrode contour curve, and obtaining the width value corresponding to the negative electrode coated thinning area and the thickness value corresponding to the negative electrode material area; determining the surface density of the negative electrode thinning area according to the product of the thickness value corresponding to the negative electrode coated thinning area and the width value corresponding to the negative electrode material area, the material area surface density corresponding to the negative electrode material area, and the negative electrode cross-sectional area.

[0074] Specifically, based on the interval endpoint values ​​corresponding to the independent variables in the negative electrode contour curve, such as [0, ],Will Substitute into the negative electrode profile curve to calculate the corresponding dependent variable as follows , thereby obtaining the width of the negative electrode thinning area and the thickness of the negative electrode material area Substitute the negative electrode cross-sectional area into the calculation formula of the negative electrode thinning area density , you can calculate .

[0075] 102A2. Determine the negative electrode thinning area density corresponding to the negative electrode thinning area based on the material area area density corresponding to the negative electrode material area and the initial contour curve.

[0076] Specifically, since the calculation method of the surface density of the negative electrode thinning area is the same as that of the positive electrode thinning area, the calculation formula of the surface density of the negative electrode thinning area is as follows:

[0077] ; (5)

[0078] In formula (5), It is expressed as the width of the negative electrode thinning area, It is expressed as the thickness of the negative electrode material area,

[0079] Expressed as the surface density of the negative electrode thinning area, Expressed as The surface density of the material area corresponding to the material area, Expressed as the cross-sectional area of ​​the negative electrode thinning area.

[0080] 102A3. Determine the positive electrode areal density based on the positive electrode thinning area areal density and the material area areal density corresponding to the positive electrode material area.

[0081] Specifically, the positive electrode surface density is the sum of the surface density of the positive electrode thinning area and the surface density of the material area corresponding to the positive electrode material area, that is:

[0082] 102A4, determining the negative electrode area density based on the negative electrode thinning area density and the material area density corresponding to the negative electrode material area.

[0083] Specifically, the negative electrode area density is the sum of the negative electrode thinning area density and the material area density corresponding to the negative electrode material area, that is:

[0084] 102B, determining the initial positive and negative electrode capacity ratio based on the positive electrode area density and the negative electrode area density.

[0085] Specifically, after the positive electrode area density and the negative electrode area density are determined, the initial positive and negative electrode capacity ratio is determined based on the active material gram capacity, the active material content percentage, the positive electrode area density and the negative electrode area density corresponding to the positive electrode material area and the negative electrode material area, that is, the initial positive and negative electrode capacity ratio CB can be calculated, and the calculation formula of the initial positive and negative electrode capacity ratio is as follows:

[0086] ; (6)

[0087] Understandably, in the embodiment, the initial positive and negative electrode capacity ratio can be calculated according to the initial profile curve. Since the initial profile curve is more accurate, the initial positive and negative electrode capacity ratio is also more accurate, thereby improving the accuracy of the initial positive and negative electrode capacity ratio calculation.

[0088] It should be noted that the initial profile curve includes an initial upper limit profile curve and an initial lower limit profile curve. For the positive electrode profile curve, it includes a positive electrode upper limit profile curve and a positive electrode lower limit profile curve ; for the negative electrode profile curve , it includes a negative electrode upper limit profile curve and a negative electrode lower limit profile curve , in order to ensure the accuracy of the subsequent verification of the initial positive and negative electrode capacity ratio, the maximum value CBmax and the minimum value CBmin of the initial positive and negative electrode capacity ratio can be calculated:

[0089] ;(7)

[0090] ;(8)

[0091] 103, if the initial positive and negative electrode capacity ratio meets the preset positive and negative electrode capacity ratio, the initial profile curve is determined as the boundary of the initial coating thinning area.

[0092] The preset positive and negative electrode capacity ratio is a preset positive and negative electrode capacity ratio threshold value used to determine whether the initial coating thinning area is accurate. In this embodiment, the preset positive and negative electrode capacity ratio CB0 includes a lower limit value CB0min and an upper limit value CB0max of the positive and negative electrode capacity ratio.

[0093] Specifically, when the maximum value of the initial positive and negative electrode capacity ratio is less than the upper limit value of the positive and negative electrode capacity ratio, and the minimum value of the initial positive and negative electrode capacity ratio is greater than the lower limit value of the positive and negative electrode capacity ratio, i.e., CBmax < CB0max and CBmin > CB0min, it is determined that the initial positive and negative electrode capacity ratio satisfies the preset positive and negative electrode capacity ratio, indicating that the initial profile curve satisfies the electrode coating process condition, and therefore, the initial profile curve is determined as the boundary of the initial coating thinning area, achieving determination of the boundary of the coating thinning area of the target electrode.

[0094] Specifically, the method further includes: if the initial positive and negative electrode capacity ratio does not satisfy the preset positive and negative electrode capacity ratio, obtaining at least one profile curve constituting a next thinning area topography profile from the set of profile curves corresponding to the initial coating thinning area of the target electrode as the initial profile curve, until the boundary of the initial coating thinning area is determined.

[0095] Specifically, if the initial positive and negative electrode capacity ratio does not satisfy the preset positive and negative electrode capacity ratio, at least one profile curve constituting a next thinning area topography profile is obtained from the set of profile curves corresponding to the initial coating thinning area of the target electrode as the initial profile curve, and the step of determining the initial positive and negative electrode capacity ratio corresponding to the target electrode according to the material area surface density corresponding to the material area in the target electrode and the initial profile curve is performed, until the boundary of the initial coating thinning area is obtained.

[0096] More specifically, when the initial positive and negative electrode capacity ratio does not satisfy the preset positive and negative electrode capacity ratio, it indicates that the initial profile curve does not satisfy the electrode coating process condition, and at this time, the initial profile curve needs to be adjusted, at least one profile curve constituting a thinning area topography profile is obtained as the initial profile curve, and the corresponding initial positive and negative electrode capacity ratio is continued to be determined. When the at least one curve with the largest enclosed area is selected as the initial profile curve, the original set of profile curves can be narrowed, i.e., the initial upper limit profile curve or the lower limit profile curve is deleted, and the initial profile curve is determined in the remaining set of profile curves, i.e., the updated initial profile curve is obtained, and then the embodiment of steps 102-103 is repeatedly executed until the initial positive and negative electrode capacity ratio corresponding to the updated initial profile curve satisfies the preset positive and negative electrode capacity ratio, the updated initial profile curve is determined as the boundary of the initial coating thinning area, and thus the boundary of the initial coating thinning area is obtained.

[0097] In one example, the detection device of the laser profiler scans at a certain speed, measures the thickness data of the material area and the thinning area of the positive and negative electrode sheets transversely every 0.5 mm, fits the function h(x) = ax4+bx3+cx2+dx+e, and the upper and lower profile curves of the coating thinning area of the corresponding negative electrode sheet are respectively: h(x) 负1 = -0.0220 x 4 + 1.2588 x 3 - 26.8828 x 2 + 254.2183 x - 817.4318、h(x) 负2 = -0.0150 x 4 + 0.8585 x 3 - 18.3276 x 2 + 172.4165 x - 527.1755, and the upper and lower profile curves of the coating thinning area of the positive electrode sheet are respectively: h(x) 正1 =0.0207x 4 -1.1670x 3 +23.6862x 2 -201.1107x+677.0181、h(x)2=-0.0002 x 4 +0.0222x 3 -0.9451x 2 +17.1150x-19.3267, the width range of the positive electrode thinning area is 13mm~19mm, the width range of the corresponding negative electrode thinning area is 11.5mm~17.5mm, other physical quantities are known, and the CBmin=1.1434, CBmax=1.2492 are calculated to meet the CB value control requirements, and the production of the coating thinning area is normal, and the upper and lower profile curves of the coating thinning area of the negative electrode sheet and the upper and lower profile curves of the coating thinning area of the positive electrode sheet can be used as the boundary model of the positive and negative electrode sheet thinning area control standard of the product type.

[0098] The above boundary determination method of the electrode sheet coating thinning area, by obtaining the initial profile curve corresponding to the initial coating thinning area of the electrode sheet, determining the initial positive and negative electrode capacity ratio of the target electrode sheet according to the initial profile curve, when the initial positive and negative electrode capacity ratio meets the condition, taking the initial profile curve as the boundary of the coating thinning area of the electrode sheet, since the initial profile curve quantitatively represents the profile of the thinning area, and the determination of the boundary of the coating thinning area is based on the initial profile curve, the accuracy of the boundary design of the coating thinning area is ensured, and the rationality of the boundary design of the coating thinning area is improved by using the initial positive and negative electrode capacity ratio for rationality verification, thereby improving the electrical performance and safety performance of the battery cell.

[0099] As shown in FIG. 7, the embodiment of the present application also provides a boundary determination device 200 of a coated thinning area of a pole piece, the boundary determination device of the coated thinning area of the pole piece comprising:

[0100] The acquisition module 201 is configured to acquire at least one profile curve constituting a thinning area topography profile from a profile curve set corresponding to an initial coated thinning area of a target pole piece as an initial profile curve, the profile curve set comprising a plurality of profile curves constituting a plurality of thinning area topography profiles.

[0101] The first determination module 202 is configured to determine an initial positive and negative electrode capacity ratio corresponding to the target pole piece according to a material area surface density corresponding to a material area in the target pole piece and the initial profile curve.

[0102] The second determination module 203 is configured to determine the initial profile curve as the boundary of the initial coated thinning area if the initial positive and negative electrode capacity ratio meets a preset positive and negative electrode capacity ratio.

[0103] In an embodiment, the device further comprises:

[0104] The third determination module is configured to acquire at least one profile curve constituting a next thinning area topography profile from the profile curve set corresponding to the initial coated thinning area of the target pole piece as the initial profile curve until the boundary of the initial coated thinning area is determined if the initial positive and negative electrode capacity ratio does not meet the preset positive and negative electrode capacity ratio.

[0105] In an embodiment, the device further comprises:

[0106] The fourth determination module is configured to determine the initial coated thinning area of the target pole piece.

[0107] The test module is configured to perform a scanning test on the initial coated thinning area and the material area in the target pole piece to measure a plurality of groups of widths of the initial coated thinning area and thicknesses of the material area.

[0108] The fitting module is configured to perform curve fitting based on the plurality of groups of widths of the initial coated thinning area and the thicknesses of the material area, with the width as the independent variable and the thickness as the dependent variable, to obtain the profile curve set.

[0109] In an embodiment, the first determination module 202 is specifically configured to:

[0110] determine a surface density of the target pole piece according to the material area surface density corresponding to the material area and the initial profile curve;

[0111] determine the initial positive and negative electrode capacity ratio according to the surface density of the target pole piece.

[0112] In an embodiment, the target pole piece includes a positive pole piece and a negative pole piece, the material area in the target pole piece includes a positive material area in the positive pole piece and a negative material area in the negative pole piece, the material area surface density includes a respective material area surface density of the positive material area and the negative material area; the first determining module 202 is specifically further used for:

[0113] determining the positive surface density of the positive pole piece according to the material area surface density corresponding to the positive material area and the initial profile curve, and determining the negative surface density of the negative pole piece according to the material area surface density corresponding to the negative material area and the initial profile curve;

[0114] determining the initial positive-negative capacity ratio according to the positive surface density and the negative surface density.

[0115] In an embodiment, the initial coating thinning area includes a positive thinning area corresponding to the positive pole piece and a negative thinning area corresponding to the negative pole piece; the first determining module 202 is specifically further used for:

[0116] determining the positive thinning area surface density corresponding to the positive thinning area based on the material area surface density corresponding to the positive material area and the initial profile curve;

[0117] determining the negative thinning area surface density corresponding to the negative thinning area based on the material area surface density corresponding to the negative material area and the initial profile curve;

[0118] determining the positive surface density based on the positive thinning area surface density and the material area surface density corresponding to the positive material area;

[0119] determining the negative surface density based on the negative thinning area surface density and the material area surface density corresponding to the negative material area.

[0120] In an embodiment, the initial profile curve includes a positive profile curve corresponding to the positive thinning area; the first determining module 202 is specifically further used for:

[0121] determining the positive cross-sectional area corresponding to the positive thinning area based on the positive profile curve;

[0122] determining the positive thinning area surface density based on the positive profile curve, the positive cross-sectional area, and the material area surface density corresponding to the positive material area.

[0123] In an embodiment, the first determining module 202 is specifically further used for:

[0124] integrating the positive profile curve to obtain the positive cross-sectional area.

[0125] In an embodiment, the first determining module 202 is specifically further used for:

[0126] Determine the width of the positive electrode thinning area and the thickness of the positive electrode material area based on the respective end point values of the independent variable and the dependent variable in the positive electrode profile curve, to obtain the width value corresponding to the positive electrode coating thinning area and the thickness value corresponding to the positive electrode material area.

[0127] Determine the positive electrode thinning area surface density based on the product of the thickness value and the width value, the material area surface density corresponding to the positive electrode material area, and the positive electrode cross-sectional area.

[0128] The embodiment of the present application also provides an electronic device integrating any one of the boundary determination devices of the electrode piece coating thinning area provided by the embodiment of the present application. The electronic device comprises:

[0129] One or more processors;

[0130] Memory; and

[0131] One or more application programs, wherein the one or more application programs are stored in the memory and are configured to execute the electrode piece coating thinning area boundary determination method in any one of the electrode piece coating thinning area boundary determination method embodiments by the processor.

[0132] The embodiment of the present application also provides an electronic device integrating any one of the boundary determination devices of the electrode piece coating thinning area provided by the embodiment of the present application. As shown in FIG. 8, a structure schematic diagram of the electronic device related to the embodiment of the present application is shown, in particular:

[0133] The electronic device can include a processor 301 with one or more processing cores, a memory 302 with one or more computer readable storage media, a power supply 303, and an input unit 304, and the like. Those skilled in the art can understand that the electronic device structure shown in FIG. 8 does not constitute a limitation on the electronic device, and can include more or fewer components than shown, or combine certain components, or different component arrangements. Among them:

[0134] The processor 301 is the control center of the electronic device, which connects various parts of the entire electronic device through various interfaces and lines, executes various functions of the electronic device and processes data by running or executing software programs and / or modules stored in the memory 302, and calling data stored in the memory 302, thereby overall monitoring the electronic device. Optionally, the processor 301 can include one or more processing cores; preferably, the processor 301 can integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface and application program, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor can also not be integrated into the processor 301.

[0135] The memory 302 can be used to store software programs and modules, and the processor 301 executes various function applications and data processing by running the software programs and modules stored in the memory 302. The memory 302 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, application programs required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; and the data storage area can store data created according to the use of the electronic device, etc. In addition, the memory 302 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. Accordingly, the memory 302 can also include a memory controller to provide the processor 301 with access to the memory 302.

[0136] The electronic device also includes a power supply 303 for powering various components. Preferably, the power supply 303 can be logically connected to the processor 301 through a power management system, so as to realize functions such as management of charging, discharging, and power consumption management through the power management system. The power supply 303 can also include one or more direct current or alternating current power supplies, a recharging system, a power supply fault detection circuit, a power supply converter or inverter, a power supply status indicator, and the like.

[0137] The electronic device can also include an input unit 304, which can be used to receive input digital or character information, and generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function controls.

[0138] Although not shown, the electronic device can also include a display unit and the like, which will not be described here. Specifically, in the present embodiment, the processor 301 in the electronic device will load the executable file corresponding to the process of one or more application programs into the memory 302 according to the following instructions, and run the application programs stored in the memory 302 by the processor 301, so as to realize various functions, as follows:

[0139] From the profile curve set corresponding to the initial coating thinning area of the target pole piece, at least one profile curve constituting a thinning area topography profile is obtained as an initial profile curve, and the profile curve set includes a plurality of profile curves constituting a plurality of thinning area topography profiles;

[0140] According to the initial profile curve and the area face density corresponding to the area of the target pole piece, an initial positive and negative electrode capacity ratio of the target pole piece is determined.

[0141] If the initial positive and negative electrode capacity ratio meets a preset positive and negative electrode capacity ratio, the initial profile curve is determined as the boundary of the initial coating thinning area.

[0142] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructions, or by controlling relevant hardware by the instructions, which can be stored in a computer readable storage medium and loaded and executed by a processor.

[0143] To this end, an embodiment of the present application provides a computer readable storage medium, which can be non-volatile or volatile, and can include a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc. A computer program is stored on the storage medium, and the computer program is loaded by a processor to execute the steps in any of the methods for determining the boundary of a coated thinning area of a pole piece provided by the embodiments of the present application. For example, the computer program loaded by the processor can execute the following steps:

[0144] From the set of profile curves corresponding to the initial coated thinning area of the target pole piece, at least one profile curve constituting a thinning area topography profile is obtained as an initial profile curve, and the set of profile curves includes a plurality of profile curves constituting a plurality of thinning area topography profiles;

[0145] According to the initial profile curve and the area face density corresponding to the material area in the target pole piece, an initial positive and negative electrode capacity ratio corresponding to the target pole piece is determined.

[0146] If the initial positive and negative electrode capacity ratio meets a preset positive and negative electrode capacity ratio, the initial profile curve is determined as the boundary of the initial coated thinning area.

[0147] An embodiment of the present application also provides a computer program product, which includes a computer program / instruction, and the computer program / instruction is used to execute the steps in any of the methods for determining the boundary of a coated thinning area of a pole piece provided by the embodiments of the present application when executed by a processor.

Claims

1. A method for determining the boundary of a pole piece coating thinning area, the method comprising: Acquire at least one contour curve constituting a profile of a thinned area from a set of contour curves corresponding to an initially coated thinned area of ​​a target electrode as an initial contour curve, wherein the set of contour curves includes a plurality of contour curves constituting a plurality of profiles of thinned areas; Determine the initial positive and negative electrode capacity ratio corresponding to the target electrode piece according to the material area surface density corresponding to the material area in the target electrode piece and the initial contour curve; If the initial positive-to-negative electrode capacity ratio satisfies a preset positive-to-negative electrode capacity ratio, the initial contour curve is determined as the boundary of the initial coating thinning area.

2. The method for determining the boundary of the electrode coating thinning area according to claim 1, further comprising: If the initial positive-to-negative electrode capacity ratio does not meet the preset positive-to-negative electrode capacity ratio, at least one contour curve constituting the morphological contour of the next thinning area is obtained as the initial contour curve from the contour curve set corresponding to the initial coated thinning area of ​​the target electrode until the boundary of the initial coated thinning area is determined.

3. The method for determining the boundary of the electrode coating and thinning area according to claim 1, before obtaining at least one contour curve constituting a thinning area topography profile from the contour curve set corresponding to the initial coating and thinning area of ​​the target electrode as the initial contour curve, further comprising: Determine the initial coating thinning area of ​​the target electrode; Performing a scanning test on the initial coating and thinning area and the material area in the target electrode, and measuring multiple sets of widths of the initial coating and thinning area and thicknesses of the material area; Based on multiple sets of widths of the initial coating thinning areas and the thickness of the material area, curve fitting is performed with the width as the independent variable and the thickness as the dependent variable to obtain the contour curve set.

4. The method for determining the boundary of the electrode coating thinning area according to claim 3, wherein: The determining the initial positive and negative electrode capacity ratio corresponding to the target electrode piece according to the material area surface density corresponding to the material area in the target electrode piece and the initial contour curve includes: Determining the surface density of the target electrode according to the material area surface density corresponding to the material area and the initial contour curve; The initial positive and negative electrode capacity ratio is determined according to the surface density of the target electrode.

5. The method for determining the boundary of the electrode coating thinning area according to claim 4, wherein: The target electrode sheet includes a positive electrode sheet and a negative electrode sheet, the material area in the target electrode sheet includes a positive electrode material area in the positive electrode sheet and a negative electrode material area in the negative electrode sheet, the material area surface density includes the material area surface density corresponding to each of the positive electrode material area and the negative electrode material area, and the surface density of the target electrode sheet includes the positive electrode surface density corresponding to the positive electrode sheet and the negative electrode surface density corresponding to the negative electrode sheet; and determining the surface density of the target electrode sheet according to the material area surface density corresponding to the material area and the initial contour curve includes: Determining the positive electrode surface density corresponding to the positive electrode plate according to the material area surface density corresponding to the positive electrode material area and the initial contour curve, and determining the negative electrode surface density corresponding to the negative electrode plate according to the material area surface density corresponding to the negative electrode material area and the initial contour curve; The determining of the initial positive-to-negative electrode capacity ratio according to the target electrode surface density includes: The initial positive-to-negative electrode capacity ratio is determined according to the positive electrode areal density and the negative electrode areal density.

6. The method for determining the boundary of the electrode coating thinning area according to claim 5, wherein: The initial coating and skived area includes a positive electrode skived area corresponding to the positive electrode sheet and a negative electrode skived area corresponding to the negative electrode sheet; determining the positive electrode surface density corresponding to the positive electrode sheet according to the material area surface density corresponding to the positive electrode material area and the initial contour curve, and determining the negative electrode surface density corresponding to the negative electrode sheet according to the material area surface density corresponding to the negative electrode material area and the initial contour curve, including: Determining the positive electrode skived area surface density corresponding to the positive electrode skived area based on the material area surface density corresponding to the positive electrode material area and the initial contour curve; Determining the negative electrode skived area area density corresponding to the negative electrode skived area based on the material area area density corresponding to the negative electrode material area and the initial contour curve; Determining the positive electrode areal density based on the positive electrode skived area areal density and the material area areal density corresponding to the positive electrode material area; The negative electrode areal density is determined based on the negative electrode thinning area areal density and the material area areal density corresponding to the negative electrode material area.

7. The method for determining the boundary of the electrode coating thinning area according to claim 6, wherein: The initial contour curve includes a positive electrode contour curve corresponding to the positive electrode thinning area; and determining the positive electrode thinning area area density corresponding to the positive electrode thinning area based on the material area area density corresponding to the positive electrode material area and the initial contour curve includes: Determining a positive electrode cross-sectional area corresponding to the positive electrode thinning region based on the positive electrode profile curve; The positive electrode thinning area surface density is determined based on the positive electrode contour curve, the positive electrode cross-sectional area, and the material area surface density corresponding to the positive electrode material area.

8. The method for determining the boundary of the electrode coating thinning area according to claim 7, wherein: The determining the positive electrode cross-sectional area corresponding to the positive electrode thinning region based on the positive electrode contour curve includes: The positive electrode profile curve is integrated and calculated to obtain the positive electrode cross-sectional area.

9. The method for determining the boundary of the electrode coating thinning area according to claim 7, wherein: The determining the positive electrode thinning area surface density based on the positive electrode contour curve, the positive electrode cross-sectional area, and the material area surface density corresponding to the positive electrode material area includes: Obtaining the interval endpoint value corresponding to the independent variable in the positive electrode profile curve; Determining the interval endpoint value corresponding to the dependent variable in the positive electrode profile curve based on the interval endpoint value corresponding to the independent variable in the positive electrode profile curve; Determine the width of the positive electrode skived area and the thickness of the positive electrode material area based on the interval endpoint values ​​corresponding to the independent variable and the dependent variable in the positive electrode profile curve, and obtain the width value corresponding to the positive electrode coated skived area and the thickness value corresponding to the positive electrode material area; The surface density of the positive electrode thinning area is determined according to the product of the thickness value corresponding to the positive electrode coating thinning area and the width value corresponding to the positive electrode material area, the surface density of the material area corresponding to the positive electrode material area and the positive electrode cross-sectional area.

10. The method for determining the boundary of the electrode coating thinning area according to claim 6, wherein: The initial contour curve includes a negative electrode contour curve corresponding to the negative electrode thinning area; and determining the negative electrode thinning area area density corresponding to the negative electrode thinning area based on the material area area density corresponding to the negative electrode material area and the initial contour curve includes: Determining a negative electrode cross-sectional area corresponding to the negative electrode thinning region based on the negative electrode contour curve; The negative electrode thinning area surface density is determined based on the negative electrode contour curve, the negative electrode cross-sectional area, and the material area surface density corresponding to the negative electrode material area.

11. The method for determining the boundary of the electrode coating thinning area according to claim 10, wherein: The determining the negative electrode thinning area surface density based on the negative electrode contour curve, the negative electrode cross-sectional area, and the material area surface density corresponding to the negative electrode material area includes: Obtaining the interval endpoint value corresponding to the independent variable in the negative electrode profile curve; Determining the interval endpoint value corresponding to the dependent variable in the negative electrode profile curve based on the interval endpoint value corresponding to the independent variable in the negative electrode profile curve; Determine the width of the negative electrode skived area and the thickness of the negative electrode material area based on the interval endpoint values ​​corresponding to the independent variable and the dependent variable in the negative electrode profile curve, and obtain the width value corresponding to the negative electrode coating skived area and the thickness value corresponding to the negative electrode material area; The surface density of the negative electrode thinning area is determined according to the product of the thickness value corresponding to the negative electrode coating thinning area and the width value corresponding to the negative electrode material area, the surface density of the material area corresponding to the negative electrode material area and the negative electrode cross-sectional area.

12. A device for determining the boundary of a pole piece coating thinning area, the device comprising: an acquisition module, configured to acquire, from a set of contour curves corresponding to the initial coated thinning area of ​​the target electrode, at least one contour curve constituting a profile of the thinning area as an initial contour curve, wherein the set of contour curves includes a plurality of contour curves constituting a plurality of profiles of the thinning area; A first determining module is used to determine the initial positive and negative electrode capacity ratio corresponding to the target electrode piece according to the material area surface density corresponding to the material area in the target electrode piece and the initial contour curve; The second determining module is configured to determine the initial contour curve as the boundary of the initial coating thinning area if the initial positive-to-negative electrode capacity ratio satisfies a preset positive-to-negative electrode capacity ratio.

13. An electronic device, comprising: one or more processors; Memory; as well as One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the method for determining the boundary of the pole piece coating thinning area according to any one of claims 1 to 11.

14. A computer-readable storage medium having a computer program stored thereon, wherein the computer program is loaded by a processor to execute the method for determining the boundary of a pole piece coating thinning area according to any one of claims 1 to 11.

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