Parameter determination method and system of battery cell, electronic device, storage medium and battery cell

Abstract

The application provides a parameter determination method and system of an electric core, an electronic device, a storage medium and the electric core. The method comprises the following steps: obtaining the relationship between the length and the area density of the nth group of pole pieces of the electric core to be designed; under the condition that the positive and negative electrode capacity ratios corresponding to each group of pole pieces are equal, determining the relationship between the C-face area density of the (n+1)th layer of negative pole pieces and the D-face area density of the nth layer of negative pole pieces, and the relationship between the C-face area density of the (n+1)th layer of negative pole pieces and the D-face area density of the (n+1)th layer of negative pole pieces according to the relationship between the length and the area density of the nth group of pole pieces; and determining the C-face area density of the (n+1)th layer of negative pole pieces, the D-face area density of the nth layer of negative pole pieces and the D-face area density of the (n+1)th layer of negative pole pieces according to the relationship between the area densities. The application can quickly determine the parameters of the electric core, and can ensure that the electric core designed according to the parameters has equal positive and negative electrode capacity ratios corresponding to each group of pole pieces, thereby improving the cycle performance and energy density of the electric core.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery cells, and particularly relates to a parameter determination method and system of a battery cell, an electronic device, a storage medium and a battery cell. BACKGROUND

[0002] Existing battery cell structures are various, but most of the structures are structures taking a winding needle as a central axis, and winding positive and negative electrode sheets and a separator around the winding needle. The positive and negative electrode sheets are in a circular arc shape in the winding structure, and the lengths of the positive and negative electrode sheets increase with the increase of the winding layers.

[0003] The surface density of each surface of the positive and negative electrode sheets is a key parameter for designing a battery cell. At present, the battery cell is designed by setting the same surface density for each surface of the positive electrode sheets in the same layer, setting the same surface density for the same surface of the positive electrode sheets in different layers, and setting the same surface density for the same surface of the negative electrode sheets in each layer.

[0004] Since the lengths of the positive and negative electrode sheets increase with the increase of the winding layers, in the case that the surface densities of the same surface of the negative electrode sheets in each layer are equal, the capacity ratios of the groups of adjacent positive and negative electrode sheets in the designed battery cell cannot all remain consistent, resulting in poor cycle performance and energy density of the battery cell. SUMMARY

[0005] The main purpose of the embodiments of the present application is to provide a parameter determination method and system of a battery cell, an electronic device, a storage medium and a battery cell, which aims to determine the battery cell parameters that make the positive and negative capacity ratios of the groups of electrode sheets of the battery cell equal, and further improve the cycle performance and energy density of the battery cell.

[0006] The application provides a parameter determination method of a battery cell. The battery cell to be designed includes a winding needle, a plurality of positive electrode sheets and a plurality of negative electrode sheets. The winding needle is used for winding the plurality of positive electrode sheets and the plurality of negative electrode sheets. Each positive electrode sheet includes an A surface facing away from the winding needle and a B surface facing the winding needle. Each negative electrode sheet includes a C surface facing the winding needle and a D surface facing away from the winding needle. The parameter determination method includes: obtaining a relationship between a length and a surface density of an nth group of electrode sheets of the battery cell to be designed. The relationship between the length and the surface density of the nth group of electrode sheets includes a relationship between an A surface length and an A surface surface density of an nth positive electrode sheet, a relationship between a B surface length and a B surface surface density of the nth positive electrode sheet, a relationship between a C surface length and a C surface surface density of an nth+1 negative electrode sheet, and a relationship between a D surface length and a D surface surface density of the nth negative electrode sheet. The nth positive electrode sheet is located between the nth negative electrode sheet and the nth+1 negative electrode sheet. n is a positive integer. Under the condition that the positive and negative electrode capacity ratios of each group of electrode sheets are equal, the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth negative electrode sheet, and the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth+1 negative electrode sheet are determined according to the relationship between the length and the surface density of the nth group of electrode sheets, the A surface surface density and the B surface surface density of the nth positive electrode sheet, and the B surface surface density of the nth+1 positive electrode sheet. The C surface surface density of the nth+1 negative electrode sheet, the D surface surface density of the nth negative electrode sheet and the D surface surface density of the nth+1 negative electrode sheet are determined according to the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth negative electrode sheet, and the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth+1 negative electrode sheet.

[0007] In an embodiment, the battery cell to be designed further comprises a plurality of layers of separators; the winding needle is further used to wind the plurality of layers of separators; the method for obtaining the relationship between the length and the area density of each group of electrode tabs of the battery cell to be designed comprises: obtaining a first target tab surface located between the winding needle and an A-surface target point of the nth positive electrode tab; the A-surface target point of the nth positive electrode tab comprises an A-surface starting point of the nth positive electrode tab and an A-surface ending point of the nth positive electrode tab; determining first distance information between the A-surface of the nth positive electrode tab and the winding needle according to the radius of the winding needle, the thickness of each layer of separators located between the winding needle and the A-surface target point of the nth positive electrode tab, and the relationship between the thickness of the first target tab surface and the area density of the first target tab surface; the first distance information comprises a first distance between the A-surface starting point of the nth positive electrode tab and a center point of the winding needle and a second distance between the A-surface ending point of the nth positive electrode tab and the center point; determining the relationship between the A-surface length and the A-surface area density of the nth positive electrode tab according to the first distance, a first difference value, and a first angle range corresponding to the A-surface of the nth positive electrode tab; the first difference value is a difference value of the second distance relative to the first distance; and the first angle range is a range of an included angle formed by any point on the A-surface of the nth positive electrode tab, the center point of the winding needle, and the A-surface starting point of the nth positive electrode tab with the center point of the winding needle as a vertex.

[0008] In an embodiment, after the determination of the C-surface area density of the nth+1 negative electrode tab, the D-surface area density of the nth negative electrode tab, and the D-surface area density of the nth+1 negative electrode tab, the parameter determination method further comprises: determining the C-surface length of the nth+1 negative electrode tab according to the C-surface area density of the nth+1 negative electrode tab and the relationship between the C-surface length and the C-surface area density of the nth+1 negative electrode tab; and determining the D-surface length of the nth negative electrode tab according to the D-surface area density of the nth negative electrode tab and the relationship between the D-surface length and the D-surface area density of the nth negative electrode tab.

[0009] In an embodiment, the determining the C-face area density of the (n+1)th negative electrode sheet, the D-face area density of the nth negative electrode sheet, and the D-face area density of the (n+1)th negative electrode sheet according to the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the nth negative electrode sheet, the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the (n+1)th negative electrode sheet, and the first preset relationship and / or the second preset relationship comprises: determining the C-face area density of the (n+1)th negative electrode sheet, the D-face area density of the nth negative electrode sheet, and the D-face area density of the (n+1)th negative electrode sheet according to the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the nth negative electrode sheet, the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the (n+1)th negative electrode sheet, and the first preset relationship and / or the second preset relationship; wherein the first preset relationship is a preset relationship between the C-face area density and the D-face area density of the same negative electrode sheet; the second preset relationship is a preset relationship between the area densities of the same face of different negative electrode sheets; and the first preset relationship and the second preset relationship are based on the positive / negative capacity ratio.

[0010] In an embodiment, the first preset relationship is that the proportion interval of the C-face area density of each negative electrode sheet is [45%, 50%); and the second preset relationship is that the area densities of the same face of different negative electrode sheets are not equal, and the deviation of the C-face area densities of adjacent two negative electrode sheets is less than or equal to 2%.

[0011] In an embodiment, after the relationship between the length and the area density of the nth group of sheets of the battery to be designed is obtained, the parameter determination method further comprises: setting the positive / negative capacity ratio as a target capacity ratio; determining the C-face area density of the (n+1)th negative electrode sheet according to the target capacity ratio, the relationship between the A-face length and the A-face area density of the nth positive electrode sheet, the relationship between the C-face length and the C-face area density of the (n+1)th negative electrode sheet, and the A-face area density of the nth positive electrode sheet; and determining the D-face area density of the nth negative electrode sheet according to the target capacity ratio, the relationship between the B-face length and the B-face area density of the nth positive electrode sheet, the relationship between the D-face length and the D-face area density of the nth negative electrode sheet, and the B-face area density of the nth positive electrode sheet.

[0012] The application further provides a parameter determination system of an electric core, the electric core to be designed comprising a winding needle, a plurality of layers of positive electrode sheets and a plurality of layers of negative electrode sheets; the winding needle is used for winding the plurality of layers of positive electrode sheets and the plurality of layers of negative electrode sheets; each layer of positive electrode sheet comprises an A surface facing away from the winding needle and a B surface facing towards the winding needle; each layer of negative electrode sheet comprises a C surface facing towards the winding needle and a D surface facing away from the winding needle; the parameter determination system comprises an acquisition module, a first determination module and a second determination module; the acquisition module is used for acquiring a length and area density relationship of an nth group of electrode sheets of the electric core to be designed; the length and area density relationship of the nth group of electrode sheets comprises an A surface length and A surface area density relationship of an nth layer of positive electrode sheet, a B surface length and B surface area density relationship of the nth layer of positive electrode sheet, a C surface length and C surface area density relationship of an nth+1 layer of negative electrode sheet, and a D surface length and D surface area density relationship of the nth layer of negative electrode sheet; the nth layer of positive electrode sheet is located between the nth layer of negative electrode sheet and the nth+1 layer of negative electrode sheet; n is a positive integer; the first determination module is used for determining, according to the length and area density relationship of the nth group of electrode sheets, the A surface area density and the B surface area density of the nth layer of positive electrode sheet, and the B surface area density of the nth+1 layer of positive electrode sheet, a relationship between the C surface area density of the nth+1 layer of negative electrode sheet and the D surface area density of the nth layer of negative electrode sheet, and a relationship between the C surface area density of the nth+1 layer of negative electrode sheet and the D surface area density of the nth+1 layer of negative electrode sheet, under the condition that the positive and negative electrode capacity ratios corresponding to each group of electrode sheets are equal; and the second determination module is used for determining the C surface area density of the nth+1 layer of negative electrode sheet, the D surface area density of the nth layer of negative electrode sheet and the D surface area density of the nth+1 layer of negative electrode sheet according to the relationship between the C surface area density of the nth+1 layer of negative electrode sheet and the D surface area density of the nth layer of negative electrode sheet, and the relationship between the C surface area density of the nth+1 layer of negative electrode sheet and the D surface area density of the nth+1 layer of negative electrode sheet.

[0013] The application further provides an electronic device, which comprises a memory and a processor, the memory stores a computer program, and the processor implements the parameter determination method when executing the computer program.

[0014] The application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the parameter determination method.

[0015] The application further provides an electric core, which comprises parameters determined by the parameter determination method.

[0016] This application provides a method, system, electronic device, storage medium, and battery cell for determining battery cell parameters. Based on the relationship between the surface density of the C-side of the (n+1)th negative electrode layer and the surface density of the D-side of the nth negative electrode layer, and the relationship between the surface density of the C-side of the (n+1)th negative electrode layer and the surface density of the D-side of the (n+1)th negative electrode layer, under the condition that the positive and negative electrode capacity ratios corresponding to each group of electrode sheets are equal, the battery cell parameters can be quickly determined. Furthermore, it can ensure that the battery cell designed according to these parameters has an equal positive and negative electrode capacity ratio for each group of electrode sheets, thereby improving the cycle performance and energy density of the battery cell. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the method for determining the parameters of a battery cell provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the electrode of the battery cell provided in the embodiments of this application. Figure 1 ;

[0019] Figure 3 This is a schematic diagram of the electrode of the battery cell provided in the embodiments of this application. Figure 2 ;

[0020] Figure 4a This is a schematic diagram of the electrode length ratio of the battery cells in the scheme provided in the embodiments of this application;

[0021] Figure 4b This is a schematic diagram of the electrode surface density of the battery cells provided in the embodiments of this application;

[0022] Figure 4c This is a schematic diagram of the positive and negative electrode capacity ratio of the battery cells in the scheme provided in the embodiments of this application;

[0023] Figure 5a This is a schematic diagram of the positive and negative electrode capacity ratio of the control group cells provided in the embodiments of this application. Figure 1 ;

[0024] Figure 5b This is a schematic diagram of the positive and negative electrode capacity ratio of the control group cells provided in the embodiments of this application. Figure 2 ;

[0025] Figure 6 This is a schematic diagram of the battery cell parameter determination system provided in the embodiments of this application;

[0026] Figure 7 This is a schematic diagram of the structure of an embodiment of the electronic device provided in this application. Detailed Implementation

[0027] With reference to the drawings, the technical solutions in the embodiments of the present application will be clearly described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art are within the scope of the present application.

[0028] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a particular order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a category and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in a "or" relationship.

[0029] The parameter determination method of the battery cell provided by the embodiments of the present application can be applied to an electronic device, and further, can be applied to software of the electronic device; wherein the electronic device can be a terminal or a server. In some embodiments, the terminal can be a notebook computer, a desktop computer, etc.; the server can be configured as a stand-alone physical server, or as a server cluster or distributed system composed of multiple physical servers; the software can be an application that implements the parameter determination method of the battery cell, etc., but is not limited to the above forms.

[0030] The parameter determination method of the battery cell provided by the embodiments of the present application will be described in detail below with reference to the drawings and specific embodiments.

[0031] The parameter determination method of the battery cell provided by the embodiments of the present application, the battery cell to be designed includes a winding needle, a plurality of positive electrode sheets and a plurality of negative electrode sheets, the winding needle is used to wind the plurality of positive electrode sheets and the plurality of negative electrode sheets; each positive electrode sheet includes an A surface facing away from the winding needle and a B surface facing toward the winding needle; each negative electrode sheet includes a C surface facing toward the winding needle and a D surface facing away from the winding needle. Please refer to Figure 1 The parameter determination method of the battery cell provided by the embodiments of the present application can include:

[0032] Step S101: obtaining a length and area density relationship of an n th group of electrode sheets of the battery to be designed; the length and area density relationship of the n th group of electrode sheets comprises a relationship between an A-surface length and an A-surface area density of an n th positive electrode sheet, a relationship between a B-surface length and a B-surface area density of the n th positive electrode sheet, a relationship between a C-surface length and a C-surface area density of an n+1 th negative electrode sheet, and a relationship between a D-surface length and a D-surface area density of an n th negative electrode sheet; the n th positive electrode sheet is located between the n th negative electrode sheet and the n+1 th negative electrode sheet; n is a positive integer;

[0033] Step S102: under a condition that a positive and negative electrode capacity ratio corresponding to each group of electrode sheets is equal, determining, according to the length and area density relationship of the n th group of electrode sheets, the A-surface area density and the B-surface area density of the n th positive electrode sheet, and the B-surface area density of the n+1 th positive electrode sheet, a relationship between the C-surface area density of the n+1 th negative electrode sheet and the D-surface area density of the n th negative electrode sheet, and a relationship between the C-surface area density of the n+1 th negative electrode sheet and the D-surface area density of the n+1 th negative electrode sheet;

[0034] Step S103: determining the C-surface area density of the n+1 th negative electrode sheet, the D-surface area density of the n th negative electrode sheet, and the D-surface area density of the n+1 th negative electrode sheet according to the relationship between the C-surface area density of the n+1 th negative electrode sheet and the D-surface area density of the n th negative electrode sheet, and the relationship between the C-surface area density of the n+1 th negative electrode sheet and the D-surface area density of the n+1 th negative electrode sheet.

[0035] The embodiment of the present application can quickly determine the parameters of the battery under the condition that the positive and negative electrode capacity ratio corresponding to each group of electrode sheets is equal, and can ensure that the battery designed according to the parameters has the positive and negative electrode capacity ratio corresponding to each group of electrode sheets equal, thereby improving the cycle performance and energy density of the battery.

[0036] As Figure 2As shown, each positive electrode layer includes a positive current collector r and coating areas on both sides of the positive current collector r. Optionally, for each positive electrode layer, the coating area of ​​the positive current collector r facing away from the winding needle is defined as surface A of the positive electrode layer, which is a convex surface, and the coating area of ​​the positive current collector r facing the winding needle is defined as surface B of the positive electrode layer, which is a concave surface. Similarly, each negative electrode layer includes a negative current collector s and coating areas on both sides of the negative current collector s. Optionally, for each negative electrode layer, the coating area of ​​the negative current collector s facing away from the winding needle is defined as surface D of the negative electrode layer, which is a convex surface, and the coating area of ​​the negative current collector s facing the winding needle is defined as surface C of the negative electrode layer, which is a concave surface. Optionally, the A-side of the nth positive electrode, the B-side of the nth positive electrode, the D-side of the nth negative electrode, and the C-side of the (n+1)th negative electrode are defined as the nth group of electrodes, with the A-side of the nth positive electrode facing the C-side of the (n+1)th negative electrode and the B-side of the nth positive electrode facing the D-side of the nth negative electrode.

[0037] like Figure 3 As shown, the negative electrode can be divided into multiple layers of negative electrode, and the positive electrode into multiple layers of positive electrode, according to the number of turns of the winding needle simultaneously with the positive electrode. Furthermore, the starting point C of the C-plane of the first layer of negative electrode can be defined as the intersection of the cross-section L of the winding needle in the width direction of the negative electrode and the center line of the negative current collector s of the first layer of negative electrode. 10 Starting from the C-plane of the first negative electrode sheet, point C... 10 Starting from the center line of the negative current collector 's' of the first negative electrode sheet, rotate 360 ​​degrees around the center point of the winding needle in the winding direction of the first negative electrode sheet. The position reached on the center line of the negative current collector 's' of the first negative electrode sheet is defined as the end point C of the C surface of the first negative electrode sheet. 11 Next, the end point C of the C-surface of the first layer of negative electrode sheet can be... 11 , defined as the starting point C of the C-plane of the second negative electrode sheet. 20 Starting from the C-plane of the second negative electrode sheet, point C... 20 Starting from the center line of the negative current collector 's' of the second negative electrode sheet, rotate 360 ​​degrees around the center point of the winding needle in the winding direction of the second negative electrode sheet. The position reached on the center line of the negative current collector 's' of the second negative electrode sheet is defined as the end point C of the C surface of the second negative electrode sheet. 21 Following the same pattern, the starting point C of the C-plane of the nth negative electrode sheet can be obtained. n0 The end point C of the C-plane of the nth negative electrode sheet n1 .

[0038] Likewise, the intersection of the cross line L' of the starting position of the positive electrode tab synchronously coiled with the winding needle of the negative electrode tab in the width direction and the positive electrode current collector r center line of the 1st layer positive electrode tab is defined as the B face starting point B of the 1st layer positive electrode tab 10 Optionally, the cross line L and the cross line L' are located on the same straight line; then, the position on the positive electrode current collector r center line of the 1st layer positive electrode tab reached by rotating 360 degrees around the winding needle center point from the B face starting point B of the 1st layer positive electrode tab in the winding direction of the 1st layer positive electrode tab is defined as the B face ending point B of the 1st layer positive electrode tab 10 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab 11 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab 11 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab 20 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab 20 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab 21 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab n0 ; then, the B face ending point B of the 1st layer positive electrode tab is defined as the B face starting point B of the 2nd layer positive electrode tab n1 .

[0039] Further, the intersection of the cross line L and the edge line of the 1st layer negative electrode tab D face away from the winding needle is defined as the D face starting point D of the 1st layer negative electrode tab 10 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 10 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 11 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 11 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 20 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 20 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab 21 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tab n0 ; then, the D face ending point D of the 1st layer negative electrode tab is defined as the D face starting point D of the 2nd layer negative electrode tabn1 .

[0040] Similarly, the intersection of the cross line L' and the edge line of the A face of the first layer of positive electrode tabs away from the winding needle can be defined as the A face starting point A of the first layer of positive electrode tabs 10 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs 10 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs 11 ; then, the A face ending point A of the first layer of positive electrode tabs can be defined as the A face ending point A of the first layer of positive electrode tabs 11 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs 20 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs 20 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs 21 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs n0 , the A face starting point A of the first layer of positive electrode tabs can be defined as the A face starting point A of the first layer of positive electrode tabs n1 .

[0041] Optionally, the battery to be designed further includes a plurality of layers of separators, and the winding needle is further used for winding the plurality of layers of separators. In an embodiment, the obtaining, in the step S101, of the relationship between the length and the area density of each group of tabs of the battery to be designed includes:

[0042] obtaining a first target tab face located between the winding needle and an A face target point of the nth layer of positive electrode tabs; the A face target point of the nth layer of positive electrode tabs includes the A face starting point of the nth layer of positive electrode tabs and the A face ending point of the nth layer of positive electrode tabs;

[0043] determining, according to the radius of the winding needle, the thickness of each layer of separators located between the winding needle and the A face target point of the nth layer of positive electrode tabs, and the relationship between the thickness of the first target tab face and the area density of the first target tab face, first distance information of the A face of the nth layer of positive electrode tabs from the winding needle; the first distance information includes a first distance between the A face starting point of the nth layer of positive electrode tabs and the center point of the winding needle, and a second distance between the A face ending point of the nth layer of positive electrode tabs and the center point;

[0044] According to the first distance, the first difference value, and the first angle range corresponding to the A surface of the n th layer positive electrode tab, the relationship between the A surface length and the A surface area density of the n th layer positive electrode tab is determined; the first difference value is the difference value of the second distance relative to the first distance; and the first angle range is the range of the included angle formed by the center point of the winding needle, any point on the A surface of the n th layer positive electrode tab, the center point of the winding needle, and the starting point of the A surface of the n th layer positive electrode tab, with the center point of the winding needle as the vertex.

[0045] Please combine Figure 2 and Figure 3 Before the negative electrode tab and the positive electrode tab are synchronously wound on the winding needle, the number of layers of the negative electrode tab wound on the winding needle alone is defined as the pre-winding layer number of the negative electrode tab, the number of layers of the separator wound on the winding needle before the negative electrode tab and the positive electrode tab are synchronously wound on the winding needle is defined as the pre-winding layer number of the separator, the pre-winding layer number of the negative electrode tab that is less than 1 turn from the start position of the separate winding to the start position of the synchronous winding of the negative electrode tab and the positive electrode tab is considered to be 0, and the pre-winding layer number of the separator that is less than 1 turn is considered to be 0.

[0046] Specifically, in the case where the A surface target point of the n th layer positive electrode tab is the starting point of the A surface of the n th layer positive electrode tab, if n = 1, the first target tab surface can include the following target tab surfaces: one C surface and one D surface of each layer of the pre-wound negative electrode tab, one C surface and one D surface of the first layer of the negative electrode tab, and one A surface and one B surface of the first layer of the positive electrode tab; if n > 1, the first target tab surface can include the following target tab surfaces: one C surface and one D surface of each layer of the pre-wound negative electrode tab, one C surface and one D surface of each layer of the first layer to the n th layer of the negative electrode tab, and one A surface and one B surface of each layer of the first layer to the n th layer of the positive electrode tab.

[0047] Specifically, in the case where the A surface target point of the n th layer positive electrode tab is the end point of the A surface of the n th layer positive electrode tab, if n = 1, the first target tab surface can include one C surface and one D surface of each layer of the pre-wound negative electrode tab, two C surfaces and two D surfaces of the first layer of the negative electrode tab, and two A surfaces and two B surfaces of the first layer of the positive electrode tab; if n > 1, the first target tab surface can include one C surface and one D surface of each layer of the pre-wound negative electrode tab, one C surface and one D surface of each layer of the first layer to the n-1 th layer of the negative electrode tab, two C surfaces and two D surfaces of the n th layer of the negative electrode tab, one A surface and one B surface of each layer of the first layer to the n-1 th layer of the positive electrode tab, and two A surfaces and two B surfaces of the n th layer of the positive electrode tab.

[0048] Optionally, the relationship between the thickness of the target tab surface and the area density of the target tab surface is:

[0049] The thickness of the target tab surface = the area density of the target tab surface / the compaction thickness + the thickness of the foil;

[0050] Wherein, the compaction thickness and the foil thickness are invariants, and the foil thickness = the thickness of the target electrode tab surface / 2.

[0051] Optionally, before the positive electrode tab and the negative electrode tab are synchronously wound with the winding needle, the thickness of the pre-wound separator between the negative electrode tab and the winding needle and between the positive electrode tab and the negative electrode tab is 2F; after the positive electrode tab and the negative electrode tab are synchronously wound with the winding needle, the thickness of the wound separator between the positive electrode tab and the negative electrode tab is F.

[0052] Optionally, the first distance r between the A surface starting point of the nth layer of positive electrode tab and the winding needle is determined by formulas (1), (2), and (3). An0 :

[0053] r An0 = R0 + F + tC n + TD n + TA n + TB n , n = 1 (1)

[0054]

[0055] Wherein, TC n is the C surface thickness of the nth layer of negative electrode tab, TD n is the D surface thickness of the nth layer of negative electrode tab, TA n is the A surface thickness of the nth layer of negative electrode tab, TB n is the B surface thickness of the nth layer of negative electrode tab, TC i is the C surface thickness of the i layer of negative electrode tab, TD i is the D surface thickness of the i layer of negative electrode tab, TA i is the A surface thickness of the i layer of positive electrode tab, TB i is the B surface thickness of the i layer of negative electrode tab, Y is the pre-wound layer number of the negative electrode tab, TC j is the C surface thickness of the j layer of pre-wound negative electrode tab, TD j is the D surface thickness of the j layer of pre-wound negative electrode tab, W is the pre-wound layer number of the separator, and H is the radius of the winding needle; Y, TC j , TD j , W, Y, F, and H are preset values; TC i , TD i , TA i , TB i , TC n , TD n , TA n , and TB n may be expressed by the surface density of the corresponding surface based on the relationship between the thickness of the target electrode tab surface and the surface density of the target electrode tab surface.

[0056] Optionally, the second distance r between the A face end point of the n th positive electrode tab and the winding needle is determined by formulas (3), (4), and (5) An1 :

[0057] r An1 =R0+3xF+2x(TC n +TD n +TA n +TB n ), n=1 (4)

[0058]

[0059] Then, the relationship between the A face length and the A face area density of the n th negative electrode tab can be determined by formulas (1) to (7):

[0060]

[0061] Δr An =r An1 -r An0 (7)

[0062] wherein, LA n is the A face length of the n th positive electrode tab, θ is an angle formed by a point on the A face of the n th positive electrode tab, the center point of the winding needle, and the A face start point of the n th positive electrode tab, with the center point of the winding needle as the vertex, and the angle ranges from θ An0 to θ An1 , θ An0 corresponds to the angle at the A face start point of the n th positive electrode tab, and optionally, θ An0 = 0 degree, and θ An1 corresponds to the angle at the A face end point of the n th positive electrode tab, and optionally, θ An1 = 360 degrees.

[0063] The embodiments of the present application determine the first distance information between the A face of the n th positive electrode tab and the winding needle based on the first target tab face thickness between the A face of the n th positive electrode tab and the winding needle, and determine the A face length of the circular arc-shaped n th negative electrode tab based on the first distance information between the A face of the n th positive electrode tab and the winding needle and the first angle range corresponding to the A face of the n th positive electrode tab, so that the relationship between the A face length and the A face area density of the n th positive electrode tab can be accurately determined based on the relationship between the target tab face thickness and the target tab face area density.

[0064] In an embodiment, the obtaining of the relationship between the length and the area density of the plurality of tabs of the to-be-designed battery cell in step S101 includes:

[0065] obtaining a second target pole surface between the winder and the C-face target point of the nth negative pole piece; the C-face target point of the nth negative pole piece includes a C-face start point of the nth negative pole piece and a C-face end point of the nth negative pole piece;

[0066] determining second distance information of the C-face of the nth negative pole piece from the winder according to the relationship between the thickness of the second target pole surface and the area density of the second target pole surface; the second distance information includes a third distance between the C-face start point of the nth negative pole piece and the center point of the winder and a fourth distance between the C-face end point of the nth negative pole piece and the center point of the winder;

[0067] determining the relationship between the C-face length of the nth negative pole piece and the C-face area density according to the third distance, the second difference value and the second angle range corresponding to the C-face of the nth negative pole piece; the second difference value is the difference between the fourth distance and the third distance; the second angle range is the range of the included angle formed by any point on the C-face of the nth negative pole piece, the center point of the winder and the C-face start point of the nth negative pole piece.

[0068] Specifically, in the case that the C-face target point of the nth negative pole piece is the C-face start point of the nth positive pole piece, if n = 1, the second target pole surface can include the following target pole surfaces: one C-face and one D-face of each layer of the pre-wound negative pole pieces, one C-face of the first layer of negative pole pieces; if n > 1, the second target pole surface can include one C-face and one D-face of each layer of the pre-wound negative pole pieces, one C-face and one D-face of each layer of the first to (n-1)th negative pole pieces, one A-face and one B-face of each layer of the first to nth positive pole pieces, and one C-face of the nth negative pole piece.

[0069] Specifically, in the case that the C-face target point of the nth negative pole piece is the C-face end point of the nth positive pole piece, if n = 1, the second target pole surface can include the following target pole surfaces: one C-face and one D-face of each layer of the pre-wound negative pole pieces, two C-faces and one D-face of the first layer of negative pole pieces, and one A-face and one B-face of the first layer of positive pole pieces; if n > 1, the second target pole surface can include one C-face and one D-face of each layer of the pre-wound negative pole pieces, one C-face and one D-face of each layer of the first to (n-1)th negative pole pieces, two C-faces of the nth negative pole piece, one D-face of the nth negative pole piece, and one A-face and one B-face of each layer of the first to nth positive pole pieces.

[0070] Optionally, the third distance r Cn0 :

[0071] rCn0 = R0 + TC n , n = 1 (8)

[0072]

[0073] wherein, TC n is the C-face thickness of the nth negative electrode tab, TC i is the C-face thickness of the ith negative electrode tab, TD i is the D-face thickness of the ith negative electrode tab, TA i is the A-face thickness of the ith positive electrode tab, TB i is the B-face thickness of the ith negative electrode tab; TC n , TC i , TD i , TA i , TB i may be expressed in terms of the area density of the corresponding face based on the relationship between the thickness of the target tab face and the area density of the target tab face.

[0074] Alternatively, the fourth distance r Cn1 between the C-face end point of the nth negative electrode tab and the winding needle is determined by formula (3), (10), (11):

[0075] r Cn1 = R0 + 2xF + TC n + TD n + TA n + TB n , n = 1 (10)

[0076]

[0077] wherein, TD n is the D-face thickness of the nth negative electrode tab, TA n is the A-face thickness of the nth negative electrode tab, TB n is the B-face thickness of the nth negative electrode tab; TD n , TA n , TB n may be expressed in terms of the area density of the corresponding face based on the relationship between the thickness of the target tab face and the area density of the target tab face.

[0078] Then, the relationship between the C-face length and the C-face area density of the nth negative electrode tab can be determined by formula (3), formula (8) to formula (13):

[0079]

[0080] Ar Cn = r Cn1 - r Cn0(13)

[0081] wherein, LC n is the C-face length of the nth negative electrode tab, and θ is an included angle formed by any point on the C-face of the nth negative electrode tab, the center point of the winding needle, and the starting point of the C-face of the nth negative electrode tab, the included angle ranging from [θ Cn0 , θ Cn1 ], θ Cn0 corresponding to the included angle at the starting point of the C-face of the nth negative electrode tab, and θ Cn0 = 0 degree, θ Cn1 corresponding to the included angle at the ending point of the C-face of the nth negative electrode tab, and θθ Cn1 = 360 degrees.

[0082] The embodiments of the present application determine the first distance information between the C-face of the nth negative electrode tab and the winding needle based on the second target tab-face thickness between the C-face of the nth negative electrode tab and the winding needle, and determine the C-face length of the circular-arc-shaped nth negative electrode tab based on the first distance information between the C-face of the nth negative electrode tab and the winding needle and the first angle range corresponding to the C-face of the nth negative electrode tab, so that the relationship between the C-face length of the nth negative electrode tab and the C-face area density can be accurately determined through the relationship between the target tab-face thickness and the target tab-face area density.

[0083] In addition, the relationship between the B-face length of the nth positive electrode tab and the B-face area density, and the relationship between the D-face length of the nth negative electrode tab and the D-face area density can refer to the determination process of the relationship between the A-face length of the nth positive electrode tab and the A-face area density and / or the determination process of the relationship between the C-face length of the nth negative electrode tab and the C-face area density in the above embodiments, which will not be described herein.

[0084] Then, the positive / negative capacity ratio corresponding to the nth group of tabs can be determined through formulas (14) and (15):

[0085]

[0086] wherein, CB Cn+1 / An is the capacity ratio of the C-face of the (n+1)th negative electrode tab in the nth group of tabs to the A-face of the nth positive electrode tab, LC n+1 is the C-face length of the (n+1)th negative electrode tab, σC n+1 is the C-face area density of the (n+1)th negative electrode tab, MC n+1 is the C-face mass capacity of the (n+1)th negative electrode tab, PC n+1 is the C-face active material content of the (n+1)th negative electrode tab, WC n+1 is the C-face width of the (n+1)th negative electrode tab, LA n is the A-face length of the nth positive electrode tab, and σAn MAis the A-face area density of the nth layer of positive electrode sheet n PAis the A-face capacity per unit mass of the nth layer of positive electrode sheet n WAis the A-face active material content of the nth layer of positive electrode sheet n is the A-face width of the nth layer of positive electrode sheet. Wherein, MC n+1 , PC n+1 , WC n+1 , σA n , MA n , PA n , WA n is the set value, LA n can be obtained by substituting σA n into formula (6).

[0087] CB Dn / Bn is the capacity ratio of the D-face of the nth layer of negative electrode sheet to the B-face of the nth layer of positive electrode sheet in the nth group of electrode sheets, LD n is the D-face length of the nth layer of negative electrode sheet, σD n is the D-face area density of the nth layer of negative electrode sheet, MD n is the D-face capacity per unit mass of the nth layer of negative electrode sheet, PD n is the D-face active material content of the nth layer of negative electrode sheet, WD n is the D-face width of the nth layer of negative electrode sheet, LB n is the B-face length of the nth layer of positive electrode sheet, σB n is the B-face area density of the nth layer of positive electrode sheet, MB n is the B-face capacity per unit mass of the nth layer of positive electrode sheet, PB n is the B-face active material content of the nth layer of positive electrode sheet, WB n is the B-face width of the nth layer of positive electrode sheet. Wherein, MD n , PD n , WD n , σB n , MB n , PB n , WB n is the set value, LB n can be obtained by substituting σB n into the relationship formula of the B-face length and the B-face area density of the nth layer of positive electrode sheet.

[0088] Optionally, the capacity ratio of the positive electrode to the negative electrode corresponding to each group of the pole pieces in the step S102 is equal, including: the capacity ratio of the C face of the (n+1)th layer of the negative electrode pole piece in the nth group to the A face of the nth layer of the positive electrode pole piece is equal to the capacity ratio of the D face of the nth layer of the negative electrode pole piece to the B face of the nth layer of the positive electrode pole piece, and the capacity ratio of the C face of the (n+1)th layer of the negative electrode pole piece in the nth group to the A face of the nth layer of the positive electrode pole piece is equal to the capacity ratio of the D face of the (n+1)th layer of the negative electrode pole piece in the (n+1)th group to the B face of the (n+1)th layer of the positive electrode pole piece.

[0089] In an embodiment, the step S102 is implemented as follows: under the condition that the capacity ratio of the positive electrode to the negative electrode corresponding to each group of the pole pieces is equal, the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the nth layer of the negative electrode pole piece, and the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the (n+1)th layer of the negative electrode pole piece are determined according to the length of the nth group of the pole pieces, the A face surface density and the B face surface density of the nth layer of the positive electrode pole piece, and the B face surface density of the (n+1)th layer of the positive electrode pole piece, including:

[0090] Optionally, CB Dn / Bn = CB Cn+1 / An = CB Dn+1 / Bn+1 Based on the A face surface density σA n , the B face surface density σB n of the nth layer of the positive electrode pole piece, and the B face surface density σB n+1 of the (n+1)th layer of the positive electrode pole piece, the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the nth layer of the negative electrode pole piece, and the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the (n+1)th layer of the negative electrode pole piece are obtained by referring to the above formulas (1)-(15).

[0091] In an embodiment, the determination of the C face surface density of the (n+1)th layer of the negative electrode pole piece, the D face surface density of the nth layer of the negative electrode pole piece, and the D face surface density of the (n+1)th layer of the negative electrode pole piece according to the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the nth layer of the negative electrode pole piece, and the relationship between the C face surface density of the (n+1)th layer of the negative electrode pole piece and the D face surface density of the (n+1)th layer of the negative electrode pole piece in the step S103 includes:

[0092] The D face surface density of the 1st layer of the negative electrode pole piece is set as the target surface density;

[0093] The C-face area density of the (n+1)th negative electrode tab, the D-face area density of the nth negative electrode tab, and the D-face area density of the (n+1)th negative electrode tab are determined according to the target D-face area density of the first negative electrode tab, the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the nth negative electrode tab, and the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the (n+1)th negative electrode tab.

[0094] The C-face area density of the (n+1)th negative electrode tab, the D-face area density of the nth negative electrode tab, and the D-face area density of the (n+1)th negative electrode tab are determined according to the target D-face area density of the first negative electrode tab, the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the nth negative electrode tab, and the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the (n+1)th negative electrode tab.

[0095] In an embodiment, the C-face area density of the (n+1)th negative electrode tab, the D-face area density of the nth negative electrode tab, and the D-face area density of the (n+1)th negative electrode tab are determined according to the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the nth negative electrode tab, and the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the (n+1)th negative electrode tab in the step S103, comprising:

[0096] The C-face area density of the (n+1)th negative electrode tab, the D-face area density of the nth negative electrode tab, and the D-face area density of the (n+1)th negative electrode tab are determined according to the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the nth negative electrode tab, the relationship between the C-face area density of the (n+1)th negative electrode tab and the D-face area density of the (n+1)th negative electrode tab, and the first preset relationship and / or the second preset relationship.

[0097] The first preset relationship is a preset relationship between the C-face area density and the D-face area density of the same negative electrode tab, and the second preset relationship is a preset relationship between the area densities of the same face of different negative electrode tabs. The first preset relationship and the second preset relationship are set based on the positive / negative capacity ratio.

[0098] The electrode sheet surface density of the battery cell meeting the relationship between the C surface density of the (n+1)th negative electrode sheet and the D surface density of the nth negative electrode sheet and the relationship between the C surface density of the (n+1)th negative electrode sheet and the D surface density of the (n+1)th negative electrode sheet is found by setting the first preset relationship and the second preset relationship by the positive and negative electrode capacity ratio, and using the first preset relationship and / or the second preset relationship. It can be ensured that the surface density obtained by solving meets the design requirements of the battery cell, and the efficiency and effect of determining the electrode sheet surface density of the battery cell can be improved, and then the cycle performance and energy density of the battery cell designed based on the electrode sheet surface density can be improved.

[0099] Optionally, the first preset relationship is that the proportion interval of the C surface density of each negative electrode sheet is [45%, 50%).

[0100] Optionally, the second preset relationship is that the surface densities of the same face of different layers of negative electrode sheets are not equal, and the deviation of the C surface densities of adjacent two layers of negative electrode sheets is less than or equal to 2%.

[0101] The first preset relationship is set as the proportion interval of the C surface density of each negative electrode sheet is [45%, 50%), and the second preset relationship is set as the surface densities of the same face of different layers of negative electrode sheets are not equal, and the deviation of the C surface densities of adjacent two layers of negative electrode sheets is less than or equal to 2%, so that the surface density obtained by solving based on the above step S103 can not only meet the condition that the positive and negative electrode capacity ratios corresponding to each group of electrode sheets of the battery cell are equal, but also make the positive and negative electrode capacity ratios in the range of [1.01, 1.2], so that the battery cell designed based on the surface density has better cycle performance and energy density.

[0102] In an embodiment, after obtaining the relationship between the length and the surface density of the nth group of electrode sheets of the battery cell to be designed in the above step S101, the parameter determination method provided by the present application further comprises:

[0103] Setting the positive and negative electrode capacity ratio as a target capacity ratio;

[0104] Determining the C surface density of the (n+1)th negative electrode sheet according to the target capacity ratio, the relationship between the A surface length and the A surface density of the nth positive electrode sheet, the relationship between the C surface length and the C surface density of the (n+1)th negative electrode sheet, and the A surface density of the nth positive electrode sheet;

[0105] Determining the D surface density of the nth negative electrode sheet according to the target capacity ratio, the relationship between the B surface length and the B surface density of the nth positive electrode sheet, the relationship between the D surface length and the D surface density of the nth negative electrode sheet, and the B surface density of the nth positive electrode sheet.

[0106] Optionally, CB Dn / Bn = CBCn+1 / An = CB0, substituting the A-face area density of the n-th positive electrode tab into the above formula (14) to obtain the C-face area density of the (n+1)-th negative electrode tab; through CB Cn+1 / An = CB0, substituting the A-face area density of the n-th positive electrode tab into the above formula (14) to obtain the C-face area density of the (n+1)-th negative electrode tab; through CB Dn / Bn = CB0, substituting the B-face area density of the n-th positive electrode tab into the above formula (14) to obtain the C-face area density of the (n+1)-th negative electrode tab.

[0107] The embodiments of the present application set the positive and negative capacity ratio corresponding to each group of tabs as the target capacity ratio, which can directly obtain the tab area density of the battery cell based on the target capacity ratio, and can ensure that the battery cell designed based on the obtained tab area density has the equal positive and negative capacity ratio corresponding to each group of tabs, thereby improving the efficiency and effect of determining the tab area density of the battery cell, and further improving the cycle performance and energy density of the battery cell designed based on the tab area density.

[0108] In an embodiment, after determining the C-face area density of the (n+1)-th negative electrode tab, the D-face area density of the n-th negative electrode tab, and the D-face area density of the (n+1)-th negative electrode tab in the above step S103, the parameter determination method provided by the embodiments of the present application further comprises:

[0109] determining the C-face length of the (n+1)-th negative electrode tab according to the C-face area density of the (n+1)-th negative electrode tab and the relationship between the C-face length and the C-face area density of the (n+1)-th negative electrode tab;

[0110] determining the D-face length of the n-th negative electrode tab according to the D-face area density of the n-th negative electrode tab and the relationship between the D-face length and the D-face area density of the n-th negative electrode tab.

[0111] Optionally, after determining the C-face area density of the (n+1)-th negative electrode tab, the C-face area density of the (n+1)-th negative electrode tab can be substituted into the relationship between the C-face length and the C-face area density of the (n+1)-th negative electrode tab to obtain the C-face length of the (n+1)-th negative electrode tab. Similarly, after determining the D-face area density of the n-th negative electrode tab, the D-face area density of the n-th negative electrode tab can be substituted into the relationship between the D-face length and the D-face area density of the n-th negative electrode tab to obtain the D-face length of the n-th negative electrode tab.

[0112] Based on the accurate construction of the relationship between the arc-shaped tab length and the tab area density, the embodiments of the present application can accurately solve the length of each face of the arc-shaped tab by solving the tab area density that makes the positive and negative capacity ratio corresponding to each group of electrode tabs of the battery cell equal, and the battery wire designed based on the solved length of each face of the tab has the equal positive and negative capacity ratio corresponding to each group of tabs, which can improve the efficiency and effect of determining the tab length of the battery cell, and further improve the cycle performance and energy density of the battery cell designed based on the tab length.

[0113] Optionally, under the condition: the A surface density of each layer of positive electrode tab = the B surface density of each layer of positive electrode tab = 10.65 mg / cm 2 , the A surface thickness of each layer of positive electrode tab = the B surface thickness of each layer of positive electrode tab = 0.025 mm, the C surface density of the 1st layer of negative electrode tab = 4.60 mg / cm 2 , the C surface thickness of the 1st layer of negative electrode tab = 0.029 mm, the D surface density of the 1st layer of negative electrode tab = 4.80 mg / cm 2 , the D surface thickness of the 1st layer of negative electrode tab = 0.031 mm, the tab surface length obtained by the parameter determination method of the battery provided in the embodiments of the present application has the relationship shown in Figure 4a : the D surface length of the nth layer of negative electrode tab and the B surface length of the nth layer of positive electrode tab decrease with the increase of n value; the C surface length of the (n+1)th layer of negative electrode tab and the A surface length of the nth layer of positive electrode tab increase with the increase of n value; the negative electrode tab surface density obtained by the parameter determination method of the battery provided in the embodiments of the present application has the relationship shown in Figure 4b : the D surface density of the nth layer of negative electrode tab decreases with the increase of n value; the C surface density of the nth layer of negative electrode tab increases with the increase of n value; the battery designed based on the tab surface length in Figure 4a and the tab surface density in Figure 4b has the following relationship in the positive and negative electrode capacity ratio: CB Dn / Bn = CB Cn+1 / An = 1.03, that is, as shown in Figure 4c : the design average CB = 1.03, CB min = 1.03, CB max = 1.03, and the energy density = 54.62 mAh.

[0114] As shown in Figure 5a , under the parameters set by the conventional parameter determination method: the A surface density of each layer of positive electrode tab = the B surface density of each layer of positive electrode tab = 10.65 mg / cm 2 , the A surface thickness of each layer of positive electrode tab = the B surface thickness of each layer of positive electrode tab = 0.025 mm; the C surface density of each layer of negative electrode tab = the D surface density of each layer of negative electrode tab = 4.89 mg / cm 2 , the C surface of each layer of negative electrode tab = the D surface thickness of each layer of negative electrode tab = 0.0311 mm, the battery designed therefrom has the positive and negative electrode capacity ratio of each tab group not equal, the average CB of the positive and negative electrode capacity ratio of each tab group = 1.075, the minimum CB min = 1.031, the maximum CBmax = 1.117, and the energy density = 53.48 mAh.

[0115] AsFigure 5b The parameters set by another conventional parameter determination method are shown in the following table: the A-face area density of each layer of positive electrode sheet = the B-face area density of each layer of positive electrode sheet = 10.65 mg / cm 2 The A-face thickness of each layer of positive electrode sheet = the B-face thickness of each layer of positive electrode sheet = 0.025 mm; the C-face area density of each layer of negative electrode sheet = 4.66 mg / cm 2 The D-face area density of each layer of negative electrode sheet = 4.89 mg / cm 2 The C-face thickness of each layer of negative electrode sheet = 0.0297 mm, and the D-face thickness of each layer of negative electrode sheet = 0.0311 mm. The capacity ratio of the positive electrode to the negative electrode of each electrode sheet group of the designed battery is not equal. The average of the capacity ratio of the positive electrode to the negative electrode of each electrode sheet group is CB = 1.05. The minimum of the capacity ratio of the positive electrode to the negative electrode of each electrode sheet group is CB min = 1.031, and the maximum of the capacity ratio of the positive electrode to the negative electrode of each electrode sheet group is CB max = 1.07. The energy density of the battery is 54.22 mAh.

[0116] As shown in the following table, the parameters of the 5 groups of schemes are designed based on the parameter determination method provided in the present application, and the parameters of the 5 groups of controls are designed based on the conventional parameter determination method. By comparing the implementation data of the 5 groups of schemes and the 5 groups of controls, it can be known that the energy density (ED) of the battery corresponding to the 5 groups of schemes is higher than the energy density of the battery corresponding to the 5 groups of controls, which indicates that the electrode sheet area density obtained based on the parameter determination method of the battery provided in the present application can be used to design a battery with higher energy density.

[0117]

[0118] The present application also provides a parameter determination system of a battery. The battery to be designed includes a winding needle, a plurality of layers of positive electrode sheets, and a plurality of layers of negative electrode sheets. The winding needle is used to wind the plurality of layers of positive electrode sheets and the plurality of layers of negative electrode sheets. Each layer of positive electrode sheet includes an A-face facing away from the winding needle and a B-face facing toward the winding needle. Each layer of negative electrode sheet includes a C-face facing toward the winding needle and a D-face facing away from the winding needle. Figure 6 As shown in the following table, the parameters of the 5 groups of schemes are designed based on the parameter determination method provided in the present application, and the parameters of the 5 groups of controls are designed based on the conventional parameter determination method. By comparing the implementation data of the 5 groups of schemes and the 5 groups of controls, it can be known that the energy density (ED) of the battery corresponding to the 5 groups of schemes is higher than the energy density of the battery corresponding to the 5 groups of controls, which indicates that the electrode sheet area density obtained based on the parameter determination method of the battery provided in the present application can be used to design a battery with higher energy density.

[0119] The acquisition module is configured to acquire the relationship between the length and the area density of the nth group of electrode sheets of the battery to be designed. The relationship between the length and the area density of the nth group of electrode sheets includes the relationship between the A-face length and the A-face area density of the nth layer of positive electrode sheet, the relationship between the B-face length and the B-face area density of the nth layer of positive electrode sheet, the relationship between the C-face length and the C-face area density of the (n+1)th layer of negative electrode sheet, and the relationship between the D-face length and the D-face area density of the nth layer of negative electrode sheet. The nth layer of positive electrode sheet is located between the nth layer of negative electrode sheet and the (n+1)th layer of negative electrode sheet. n is a positive integer.

[0120] The first determining module is configured to determine, under the condition that the positive / negative capacity ratios of the groups of pole pieces are equal, the relationship between the length and the area density of the nth group of pole pieces, the A-face area density of the nth positive pole piece, the B-face area density of the nth positive pole piece, the B-face area density of the (n+1)th positive pole piece, the relationship between the C-face area density of the (n+1)th negative pole piece and the D-face area density of the nth negative pole piece, and the relationship between the C-face area density of the (n+1)th negative pole piece and the D-face area density of the (n+1)th negative pole piece.

[0121] The second determining module is configured to determine, according to the relationship between the C-face area density of the (n+1)th negative pole piece and the D-face area density of the nth negative pole piece, and the relationship between the C-face area density of the (n+1)th negative pole piece and the D-face area density of the (n+1)th negative pole piece, the C-face area density of the (n+1)th negative pole piece, the D-face area density of the nth negative pole piece, and the D-face area density of the (n+1)th negative pole piece.

[0122] The parameter determination system of the nuclear power unit provided in the embodiments of the present application can implement each step of the parameter determination method of the battery cell and achieve the same technical effects. To avoid repetition, no further description is given here.

[0123] Optionally, the embodiments of the present application further provide a battery cell, which comprises the parameters determined by the parameter determination method of the battery cell.

[0124] Optionally, the embodiments of the present application further provide an electronic device, which comprises a processor and a memory. The memory stores programs or instructions executable on the processor. When the programs or instructions are executed by the processor, each step of the parameter determination method of the battery cell is implemented, and the same technical effects are achieved. To avoid repetition, no further description is given here. It should be noted that the electronic device in the embodiments of the present application includes the mobile electronic device and the non-mobile electronic device.

[0125] Figure 7 To realize the hardware structure of the electronic device in the embodiments of the present application, the electronic device comprises:

[0126] The processor 701 can be implemented in the form of a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute related programs to implement the technical solutions provided in the embodiments of the present application.

[0127] The memory 702 can be implemented in the form of a read only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM), etc. The memory 702 can store an operating system and other application programs. When the technical solutions provided by the embodiments of the present specification are implemented by software or firmware, the related program codes are stored in the memory 702 and are called and executed by the processor 701 to implement the parameter determination method of the battery cell of the embodiments of the present application;

[0128] The input / output interface 703 is configured to realize information input and output.

[0129] The communication interface 704 is configured to realize the communication interaction between the device and other devices, and the communication can be realized by a wired manner (for example, a USB, a network cable, an optical fiber, etc.).

[0130] The bus 707 is configured to transmit information between various components (for example, the processor 701, the memory 702, the input / output interface 703, and the communication interface 704) of the device.

[0131] The processor 701, the memory 702, the input / output interface 703, and the communication interface 704 are connected to each other through the bus 707 to realize the communication connection between the device.

[0132] The electronic device provided by the embodiments of the present application can realize each step of the parameter determination method of the battery cell provided by the above-mentioned embodiments, and can achieve the same technical effects. To avoid repetition, details are not repeated here.

[0133] The embodiments of the present application also provide a computer readable storage medium, and the computer readable storage medium stores a program or instructions. When the program or instructions are executed by the processor, each step of the parameter determination method of the battery cell provided by the above-mentioned embodiments is realized, and the same technical effects can be achieved. To avoid repetition, details are not repeated here.

[0134] The processor is the processor in the electronic device described in the above-mentioned embodiments. The computer readable storage medium includes a computer readable storage medium, such as a computer readable memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0135] The embodiments of the present application further provide a chip, and the chip includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is configured to run a program or instructions to realize each step of the parameter determination method of the battery cell provided by the above-mentioned embodiments, and the same technical effects can be achieved. To avoid repetition, details are not repeated here.

[0136] It should be understood that the chip mentioned in the embodiments of the present application can also be referred to as a system-level chip, a system chip, a chip system, or a system-on-chip, etc.

[0137] The embodiments of the present application provide a computer program product stored in a storage medium, which is executed by at least one processor to implement each step of the parameter determination method of the battery cell as described above, and can achieve the same technical effects. To avoid repetition, it will not be described here.

[0138] It should be noted that in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such a process, method, article, or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or device that includes the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to the order of performing the functions shown or discussed, but can also include performing the functions in a substantially simultaneous manner or in reverse order, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted, or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0139] From the above description of the embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment method can be realized by means of software and the necessary general hardware platform, of course, it can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), including a plurality of instructions for making a terminal (which can be a computer, server, or network device, etc.) execute the method described in each embodiment of the present application.

[0140] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative, not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the protection scope of the claims.

Claims

1. A method of determining parameters of an electric cell, characterized in that, The to-be-designed battery cell includes a winding needle, a plurality of positive electrode sheets, and a plurality of negative electrode sheets. The winding needle is used to wind the plurality of positive electrode sheets and the plurality of negative electrode sheets. Each positive electrode sheet includes an A surface facing away from the winding needle and a B surface facing toward the winding needle. Each negative electrode sheet includes a C surface facing toward the winding needle and a D surface facing away from the winding needle. The parameter determination method includes the following steps. Obtaining a relationship between a length and a surface density of an nth group of electrode sheets of the to-be-designed battery cell. The relationship between the length and the surface density of the nth group of electrode sheets includes a relationship between an A surface length and an A surface surface density of an nth positive electrode sheet, a relationship between a B surface length and a B surface surface density of the nth positive electrode sheet, a relationship between a C surface length and a C surface surface density of an nth+1 negative electrode sheet, and a relationship between a D surface length and a D surface surface density of the nth negative electrode sheet. The nth positive electrode sheet is located between the nth negative electrode sheet and the nth+1 negative electrode sheet. n is a positive integer. Under the condition that a positive-negative capacity ratio of each group of electrode sheets is equal, determining, according to the relationship between the length and the surface density of the nth group of electrode sheets, the A surface surface density of the nth positive electrode sheet, the B surface surface density of the nth positive electrode sheet, and the B surface surface density of the nth+1 positive electrode sheet, a relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth negative electrode sheet, and a relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth+1 negative electrode sheet. Determining the C surface surface density of the nth+1 negative electrode sheet, the D surface surface density of the nth negative electrode sheet, and the D surface surface density of the nth+1 negative electrode sheet according to the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth negative electrode sheet, and the relationship between the C surface surface density of the nth+1 negative electrode sheet and the D surface surface density of the nth+1 negative electrode sheet.

2. The parameter determination method of claim 1, wherein, The to-be-designed battery cell further includes a plurality of separators. The winding needle is further used to wind the plurality of separators. The obtaining the relationship between the length and the surface density of the nth group of electrode sheets includes the following steps. Obtaining a first target electrode sheet surface located between the winding needle and an A surface target point of the nth positive electrode sheet. The A surface target point of the nth positive electrode sheet includes an A surface starting point of the nth positive electrode sheet and an A surface ending point of the nth positive electrode sheet. Determining first distance information between the A surface of the nth positive electrode sheet and the winding needle according to a radius of the winding needle, a thickness of each separator located between the winding needle and the A surface target point of the nth positive electrode sheet, and a relationship between a thickness of the first target electrode sheet surface and a surface density of the first target electrode sheet surface. The first distance information includes a first distance between the A surface starting point of the nth positive electrode sheet and a center point of the winding needle and a second distance between the A surface ending point of the nth positive electrode sheet and the center point. determining a relationship between the A-face length and the A-face area density of the nth positive electrode sheet according to the first distance, a first difference value, and a first angle range corresponding to the A-face of the nth positive electrode sheet; the first difference value is a difference value of the second distance relative to the first distance; and the first angle range is a range of an angle formed by a point on the A-face of the nth positive electrode sheet, a center point of the winding needle, and a starting point of the A-face of the nth positive electrode sheet, with the center point of the winding needle as a vertex.

3. The parameter determination method of claim 1, wherein, After the C-face area density of the (n+1)th negative electrode sheet, the D-face area density of the nth negative electrode sheet, and the D-face area density of the (n+1)th negative electrode sheet are determined, the parameter determination method further comprises: determining the C-face length of the (n+1)th negative electrode sheet according to the C-face area density of the (n+1)th negative electrode sheet and a relationship between the C-face length and the C-face area density of the (n+1)th negative electrode sheet; determining the D-face length of the nth negative electrode sheet according to the D-face area density of the nth negative electrode sheet and a relationship between the D-face length and the D-face area density of the nth negative electrode sheet.

4. The parameter determination method of claim 1, wherein The determining the C-face area density of the (n+1)th negative electrode sheet, the D-face area density of the nth negative electrode sheet, and the D-face area density of the (n+1)th negative electrode sheet according to the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the nth negative electrode sheet, and the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the (n+1)th negative electrode sheet comprises: determining the C-face area density of the (n+1)th negative electrode sheet, the D-face area density of the nth negative electrode sheet, and the D-face area density of the (n+1)th negative electrode sheet according to the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the nth negative electrode sheet, the relationship between the C-face area density of the (n+1)th negative electrode sheet and the D-face area density of the (n+1)th negative electrode sheet, and a first preset relationship and / or a second preset relationship; wherein the first preset relationship is a preset relationship between the C-face area density and the D-face area density of the same layer of negative electrode sheet; the second preset relationship is a preset relationship between the area densities of the same face of different layers of negative electrode sheet; and the first preset relationship and the second preset relationship are based on the positive / negative electrode capacity ratio.

5. The parameter determination method of claim 4, wherein, The first preset relationship is that the proportion interval of the C-face area density of each layer of negative electrode sheet is [45%, 50%]. The second preset relationship is that the area densities of the same face of different layers of negative electrode sheet are not equal, and the deviation of the C-face area densities of adjacent two layers of negative electrode sheet is less than or equal to 2%.

6. The parameter determination method of claim 1, wherein, After the relationship between the length and the area density of the nth group of sheets of the to-be-designed battery cell is obtained, the parameter determination method further comprises: setting the positive / negative electrode capacity ratio as a target capacity ratio; determining the C-face area density of the (n+1)th negative electrode sheet according to the target capacity ratio, the relationship between the A-face length and the A-face area density of the nth positive electrode sheet, the relationship between the C-face length and the C-face area density of the (n+1)th negative electrode sheet, and the A-face area density of the nth positive electrode sheet; and The D-face area density of the n-th negative electrode sheet is determined according to the target capacity ratio, the relationship between the B-face length and the B-face area density of the n-th positive electrode sheet, the relationship between the D-face length and the D-face area density of the n-th negative electrode sheet, and the B-face area density of the n-th positive electrode sheet.

7. A parameter determination system for a battery cell, characterized by The to-be-designed battery cell includes a winding needle, a plurality of positive electrode sheets, and a plurality of negative electrode sheets; the winding needle is used to wind the plurality of positive electrode sheets and the plurality of negative electrode sheets; each positive electrode sheet includes an A-face away from the winding needle and a B-face toward the winding needle; each negative electrode sheet includes a C-face toward the winding needle and a D-face away from the winding needle; and the parameter determination system includes an acquisition module, a first determination module, and a second determination module. The acquisition module is configured to acquire a relationship between lengths and area densities of an n-th group of electrode sheets of the to-be-designed battery cell; the relationship between the lengths and the area densities of the n-th group of electrode sheets includes a relationship between an A-face length and an A-face area density of an n-th positive electrode sheet, a relationship between a B-face length and a B-face area density of the n-th positive electrode sheet, a relationship between a C-face length and a C-face area density of an n+1-th negative electrode sheet, and a relationship between a D-face length and a D-face area density of the n-th negative electrode sheet; the n-th positive electrode sheet is located between the n-th negative electrode sheet and the n+1-th negative electrode sheet; and n is a positive integer. The first determination module is configured to, under a condition that positive and negative electrode capacity ratios corresponding to each group of electrode sheets are equal, determine, according to the relationship between the lengths and the area densities of the n-th group of electrode sheets, the A-face area density and the B-face area density of the n-th positive electrode sheet, and a B-face area density of an n+1-th positive electrode sheet, a relationship between a C-face area density of the n+1-th negative electrode sheet and a D-face area density of the n-th negative electrode sheet, and a relationship between the C-face area density of the n+1-th negative electrode sheet and a D-face area density of the n+1-th negative electrode sheet. The second determination module is configured to determine the C-face area density of the n+1-th negative electrode sheet, the D-face area density of the n-th negative electrode sheet, and the D-face area density of the n+1-th negative electrode sheet according to the relationship between the C-face area density of the n+1-th negative electrode sheet and the D-face area density of the n-th negative electrode sheet, and the relationship between the C-face area density of the n+1-th negative electrode sheet and the D-face area density of the n+1-th negative electrode sheet.

8. An electronic device, comprising: The electronic device includes a memory and a processor; the memory stores a computer program; and the processor implements the parameter determination method in any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer program is executed by the processor to implement the parameter determination method in any one of claims 1 to 6.

10. An electric cell characterized by The battery cell includes parameters determined by the parameter determination method in any one of claims 1 to 6.

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