Electrode sheet and manufacturing method thereof and battery cell

Abstract

The present application discloses an electrode plate, a manufacturing method thereof, and a battery cell. The electrode plate includes a current collector, and a first material layer and a second material layer arranged on the same side of the current collector; in the width direction of the current collector, the second material layer is arranged on at least one side of the first material layer; the second material has higher dynamic performance than the first material; the first material is the material of the first material layer, and the second material is the material of the second material layer. The embodiment of the present application helps to avoid lithium deposition at the edge of the first material layer by arranging a second material layer with higher dynamic performance on at least one side of the first material layer, thereby improving the service life of the electrode plate.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to an electrode plate and a manufacturing method thereof and a battery cell. Background Art

[0002] With the development of battery technology, users have higher and higher requirements for battery performance. For example, for the currently more commonly used lithium batteries, users may require them to have high charging efficiency and high power capacity.

[0003] In the related art, in order to make lithium batteries have higher energy capacity, materials with higher energy density are usually coated on the electrode plates. However, in practical applications, such electrode plates are prone to lithium deposition due to the low kinetic properties of the coating materials, resulting in a shorter service life of the electrode plates. Summary of the invention

[0004] The present application aims to provide an electrode plate and a method for manufacturing the same, and a battery cell, to at least solve the problem in the related art that the electrode plate is prone to lithium deposition, resulting in a short service life of the electrode plate.

[0005] In order to solve the above technical problems, this application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides an electrode plate, comprising: a current collector, and a first material layer and a second material layer disposed on the same side of the current collector; in a width direction of the current collector, the second material layer is disposed on at least one side of the first material layer;

[0007] The second material has higher dynamic performance than the first material; the first material is the material of the first material layer, and the second material is the material of the second material layer.

[0008] In a second aspect, the present application provides an electrode sheet manufacturing method, comprising:

[0009] A current collector is provided, wherein one side surface of the current collector includes a first region and a second region, and in a width direction of the current collector, the second region is located on at least one side of the first region;

[0010] Spraying a first material on a first area and spraying a second material on a second area to obtain an electrode sheet;

[0011] The dynamic performance of the second material is higher than that of the first material.

[0012] In a third aspect, an embodiment of the present application provides a battery cell, comprising a positive electrode sheet, a negative electrode sheet and a separator, wherein the positive electrode sheet and the negative electrode sheet are respectively connected to two sides of the separator in a thickness direction;

[0013] The negative electrode plate is the electrode plate as shown in the first aspect.

[0014] The electrode plate provided in the embodiment of the present application includes a current collector and a first material layer and a second material layer arranged on the same side of the current collector. In the width direction of the current collector, the second material layer is arranged on at least one side of the first material layer, and the dynamic performance of the second material in the second material layer is higher than the dynamic performance of the first material in the first material layer. In this way, by arranging the second material layer with higher dynamic performance on at least one side of the first material layer, it helps to avoid lithium deposition at the edge of the first material layer, thereby improving the service life of the electrode plate.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0017] Figure 1 A schematic diagram of the lithium deposition position of the electrode plate in the related art;

[0018] Figure 2 This is one of the structural schematic diagrams of an electrode plate provided by an embodiment of the present application;

[0019] Figure 3 This is the second structural schematic diagram of an electrode plate provided by an embodiment of the present application;

[0020] Figure 4 Is for Figure 2 An example diagram of a cross section of an electrode sheet shown;

[0021] Figure 5 This is the third structural schematic diagram of an electrode plate provided by an embodiment of the present application;

[0022] Figure 6 It is a schematic diagram of a structure in which a fourth material layer is provided on a single-sided area of ​​a current collector;

[0023] Figure 7 is one of the example diagrams of the location area of ​​the fourth material layer on the current collector;

[0024] Figure 8 This is the second example diagram of the location area of ​​the fourth material layer on the current collector;

[0025] Fig. 9 It is a schematic flow chart of a method for manufacturing an electrode sheet provided in another embodiment of the present application;

[0026] Fig.10It is made using production equipment Figure 2 Schematic diagram of the electrode plate shown;

[0027] Fig.11 This is one of the structural schematic diagrams of a battery cell provided in another embodiment of the present application;

[0028] Fig.12 This is the second structural schematic diagram of a battery cell provided by another embodiment of the present application;

[0029] Fig.13 This is the third structural schematic diagram of a battery cell provided by another embodiment of the present application;

[0030] Fig.14 is a schematic structural diagram of a negative electrode sheet in a battery cell provided in another embodiment of the present application;

[0031] in, Figures 2 to 8 It shows: 110 - current collector, 121 - first material layer, 122 - second material layer, 1221 - first sub-material layer, 1222 - second sub-material layer, 123 - third material layer, 124 - fourth material layer;

[0032] Fig.10 In the figure, it is shown that: 200 - current collector, 210 - first region, 221 - first sub-region, 222 - second sub-region;

[0033] Figures 11 to 14 It shows: 310 - positive electrode plate, 311 - first end, 312 - second end, 320 - negative electrode plate, 321 - first current collector, 322 - first material layer, 323 - second material layer, 324 - third material layer, 325 - fifth material layer, 326 - sixth material layer, 330 - separator, 340 - negative electrode ear, 350 - positive electrode adhesive. DETAILED DESCRIPTION

[0034] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0035] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Generally speaking, the performance of a battery is reflected in two aspects: power capacity and charging efficiency. For lithium batteries and other types of batteries, the choice of coating materials for the electrode plates in the battery cell has a great impact on the battery performance.

[0039] For example, the application of coating materials with high energy density can improve the battery's electrical energy capacity, while the application of coating materials with high kinetic performance can help improve the battery's charging efficiency.

[0040] It is easy to understand that the dynamic performance of a material can usually be reflected in indicators such as conductivity or anisotropy. For example, the better the conductivity of a material, the higher its dynamic performance can be considered to a certain extent.

[0041] Generally speaking, when the energy density of the coating material used for the electrode plate is high, the dynamic performance of the coating material will be poor.

[0042] Taking the negative electrode plate as an example, when a coating material with a higher energy density is used in the negative electrode plate, lithium deposition may occur due to the poor kinetic properties of the coating material, resulting in a reduced life of the battery cell. In the case of severe lithium deposition, it will cause safety problems for battery users.

[0043] like Figure 1 As shown, Figure 1 An example diagram showing the location of lithium deposition on the negative electrode sheet when lithium deposition occurs. Figure 1 It can be seen that the lithium deposition location is mainly located at the edge of the coating material in the negative electrode plate.

[0044] In order to solve the above lithium plating phenomenon which leads to the reduction of battery life and the resulting safety issues, Figure 2 and Figure 3 As shown, the electrode sheet provided according to some embodiments of the present application includes: a current collector 110, and a first material layer 121 and a second material layer 122 arranged on the same side of the current collector 110; in the width direction of the current collector 110, the second material layer 122 is arranged on at least one side of the first material layer 121;

[0045] The dynamic performance of the second material is higher than that of the first material; the first material is the material of the first material layer 121 , and the second material is the material of the second material layer 122 .

[0046] The electrode plate may be a negative electrode plate. Of course, in some possible implementations, in order to avoid the lithium deposition phenomenon that may exist in the positive electrode plate during the discharge of the battery cell, the electrode plate may also be a positive electrode plate. In order to simplify the description, in the following embodiments, the electrode plate is mainly used as a negative electrode plate as an example for explanation.

[0047] The electrode plate may include a current collector 110. Generally speaking, the current collector 110 may refer to a structure for collecting current. For example, in a lithium battery, the current collector 110 may be a structure such as copper foil or aluminum foil.

[0048] In this embodiment, the current collector 110 may include a surface for disposing electrode materials. Accordingly, a first material layer 121 and a second material layer 122 may be disposed on the current collector 110 .

[0049] For example, one side surface of the current collector 110 may have a first region and a second region, the first material layer 121 may be disposed on the first region, and the second material layer 122 may be disposed on the second region. In other words, the first material layer 121 and the second material layer 122 may be disposed on the same side of the current collector 110. Of course, the description of the first region and the second region here is to facilitate understanding of the arrangement of each material layer on the current collector 110, and the number, shape or area of ​​the first region and the second region can be determined according to actual needs.

[0050] In addition, the specific arrangement of the first material layer 121 and the second material layer 122 on the current collector 110 may be coating, or layer stacking, thermal penetration, etc., which is not specifically limited here. In order to simplify the description, the following mainly uses the coating method as an example for explanation.

[0051] The material of the first material layer 121 may be recorded as a first material, and the material of the second material layer 122 may be recorded as a second material. The dynamic performance of the first material is lower than the dynamic performance of the second material.

[0052] For example, the first material and the second material can be at least one of the energy storage materials of the system of graphite, graphene, silicon material, etc. For example, the first material and the second material can be specifically soft carbon, hard carbon, graphite, lithium titanate, carbon nanotubes, silicon or graphene and other lithium-inserted and alloy materials.

[0053] The material systems of the first material and the second material can be the same or different, as long as the dynamic performance of the second material is higher than that of the first material. For example, if the first material and the second material are both materials of the material system of graphite, then the second material, relative to the first material, can be a material with better anisotropy coated in the graphite, or a material with better conductivity mixed in the graphite.

[0054] The current collector 110 may be defined with a length direction and a width direction. For example, generally speaking, the current collector 110 may be rectangular in shape, and its length direction may refer to the extension direction of the longer side, and its width direction may refer to the extension direction of the shorter side. Of course, in some application scenarios, the current collector 110 in the formed battery cell may be in a wound form, in which case the width direction of the current collector 110 may correspond to the length direction of the formed battery cell.

[0055] like Figure 2 and Figure 3 As shown, the length direction of the current collector 110 can be represented by direction L, and the width direction of the current collector 110 can be represented by direction W.

[0056] In this embodiment, in the width direction of the current collector 110 , the second material layer 122 may be disposed on at least one side of the first material layer 121 .

[0057] For example, Figure 2 As shown, in one example, in the width direction of the current collector 110 , the second material layer 122 may be disposed on both sides of the first material layer 121 , that is, the second material layer 122 may occupy a plurality of regions in the current collector 110 .

[0058] For simplicity of description, the region where the first material layer 121 is located can be recorded as A, and the two regions where the second material layer 122 is located can be recorded as B and C. Accordingly, the material coated in region A can be recorded as material A, that is, the first material mentioned above; the materials coated in regions B and C can be recorded as material B and material C, respectively, and both material B and material C can be considered as the second material mentioned above.

[0059] It is worth emphasizing again that, in practical applications, the materials may be arranged in various regions by coating as in the above examples, or by layer stacking, heat penetration and other arrangements.

[0060] Since the second material has higher kinetic properties and higher diffusion capacity of lithium ions, it is not easy to produce lithium precipitation due to deposition.

[0061] In the width direction of the current collector 110, the second material layer 122 is coated on both sides of the first material layer 121, that is, Figure 1 The position where lithium deposition is prone to occur is replaced by the second material layer 122 with higher kinetic performance, thereby effectively avoiding the occurrence of lithium deposition.

[0062] At the same time, the second material layer 122 uses a second material with relatively high dynamic performance, which helps to improve the charging rate.

[0063] In addition, since the second material layer 122 is arranged on both sides of the first material layer 121 in the width direction of the current collector 110, the second material layer 122 can extend along the length direction of the current collector 110 to cover more areas where lithium deposition may occur, thereby more effectively avoiding the occurrence of lithium deposition.

[0064] like Figure 3 As shown, in another example, in the width direction of the current collector 110 , the second material layer 122 may be disposed on one side of the first material layer 121 .

[0065] Similar to the previous example, the area where the first material layer 121 is located can be marked as A, and the two areas where the second material layer 122 is located can be marked as B.

[0066] In this example, since the second material layer 122 with higher kinetic performance is provided at the edge of the first material layer 121 where lithium deposition is likely to occur, the lithium deposition phenomenon can be effectively avoided. The specific principle will not be described in detail here.

[0067] Of course, in some feasible implementations, the first material layer 121 may occupy multiple regions on the current collector 110 , so that the first material layer 121 and the second material layer 122 may be alternately distributed in the width direction of the current collector 110 .

[0068] The electrode plate provided in the embodiment of the present application includes a current collector 110 and a first material layer 121 and a second material layer 122 coated on the same side of the current collector 110. In the width direction of the current collector 110, the second material layer 122 is arranged on at least one side of the first material layer 121, and the dynamic performance of the second material of the second material layer 122 is higher than the dynamic performance of the first material of the first material layer 121; in this way, by arranging the second material layer 122 with higher dynamic performance on at least one side of the first material layer 121, it is helpful to avoid lithium deposition at the edge of the first material layer 121, thereby improving the service life of the electrode plate.

[0069] In addition, the application of the second material layer 122 with higher dynamic performance also helps to improve the charging efficiency of the battery cell including the above electrode plates.

[0070] In some examples, the energy density of the first material described above may be greater than the energy density of the second material.

[0071] Combination Figure 2 For the electrode plates, the second material with better conductivity is used in the position where lithium deposition is likely to occur, so as to avoid the occurrence of lithium deposition and improve the charging capacity. In the middle part of the electrode plate, the first material with higher energy density can be used while ensuring the corresponding charging capacity. In this way, lithium deposition can be avoided in the position where lithium deposition often occurs on the electrode plate, and the overall energy capacity of the battery cell including the electrode plate can be improved.

[0072] like Figure 4 As shown, Figure 4 for Figure 2 An example diagram of a cross section of an electrode sheet is shown. The direction W in the diagram can also be used to represent the width direction of the current collector 110 , while the direction H can include the thickness direction of the current collector 110 .

[0073] Combination Figure 4 It can be seen that the first material layer 121 and the second material layer 122 can be coated on one side surface of the current collector 110 in the thickness direction, and both the first material layer 121 and the second material layer 122 can be directly coated on the current collector 110 .

[0074] The portion of the second material layer 122 located in the region B, the first material layer 121 , and the portion of the second material layer 122 located in the region C may be sequentially arranged along the width direction of the current collector 110 .

[0075] based on Figure 4 It can be seen that in some application scenarios, in the process of coating the material layer on the current collector 110, three coating ports arranged sequentially in the width direction of the current collector 110 can be used to simultaneously spray the material on the current collector 110, thereby improving the production efficiency of the electrode plate.

[0076] Of course, it is easy to understand that Figure 4 It is an example of a cross-section of an electrode plate. In practical applications, the second material layer 122 may also be located on one side of the first material layer 121; or, the material layer may be coated on both sides of the current collector 110 in the thickness direction; or, the boundary between the first material layer 121 and the second material layer 122 may have a certain inclination angle relative to the thickness direction of the current collector 110, or the boundary may extend in a curve, etc. Examples are not given here one by one.

[0077] Similarly, in the vertical projection of the plane where the current collector 110 is located, the boundary between the first material layer 121 and the second material layer 122 can be a straight line along the length direction of the current collector 110, or it can be a curve, a wavy line, a broken line, or a straight line with a preset angle relative to the length direction of the current collector 110, etc., which is not specifically limited here.

[0078] Optionally, the second material layer 122 includes a first sub-material layer 1221 and a second sub-material layer 1222; the first sub-material layer 1221 and the second sub-material layer 1222 are respectively disposed on both sides of the first material layer 121.

[0079] The material of the first sub-material layer 1221 is the same as or different from the material of the second sub-material layer 1222 .

[0080] like Figure 2 As shown, in the width direction of the current collector 110, the second material layer 122 may be disposed on both sides of the first material layer 121. The second material layer 122 may be considered to be located in both regions B and C shown in the figure.

[0081] Region B may correspond to the first sub-material layer 1221, and region C may correspond to the second sub-material layer 1222. Accordingly, the material of the first sub-material layer 1221 may be recorded as material B, and the material of the second sub-material layer 1222 may be recorded as material C.

[0082] In this embodiment, the relative performance of material B and material C may not be limited. For example, the dynamic performance of material B may be higher than, equal to, or lower than the dynamic performance of material C.

[0083] If the width of the first sub-material layer 1221 is recorded as W_B, and the width of the second sub-material layer 1222 is recorded as W_C, then W_B and W_C may be equal or different. In addition, the shape of the first sub-material layer 1221 and the shape of the second sub-material layer 1222 may be the same or different, and are not specifically limited here.

[0084] As shown above, both material B and material C can be considered as the second material, and the dynamic performance of the second material is higher than the dynamic performance of the first material. In other words, the dynamic performance of material B and material C can be higher than the dynamic performance of material A.

[0085] In this embodiment, the second material layer 122 includes a first sub-material layer 1221 and a second sub-material layer 1222 respectively arranged on both sides of the first material layer 121, so that the second material layer 122 can be coated as much as possible on the area where lithium deposition may occur, thereby effectively avoiding the occurrence of lithium deposition.

[0086] Optionally, the electrode plate further includes a third material layer 123 coated on the current collector 110; in the length direction of the current collector 110, the third material layer 123 is disposed on at least one side of the first material layer 121;

[0087] The dynamic performance of the material of the third material layer 123 is higher than the dynamic performance of the first material.

[0088] As shown above, the position where lithium deposition is likely to occur in the electrode plate is usually at the edge of the first material layer 121. In the above embodiment, by arranging the first material layer 121 and the second material layer 122 in sequence in the width direction of the current collector 110, the occurrence of lithium deposition can be effectively prevented.

[0089] In this embodiment, in order to further prevent the occurrence of lithium deposition, a third material layer 123 with higher dynamic performance may be provided at at least one end of the first material layer 121 along the length direction.

[0090] like Figure 5 As shown, Figure 5 The structure of the electrode sheet including the first material layer 121, the second material layer 122 and the third material layer 123 is shown. The direction L may represent the length direction of the current collector 110, and the direction W may represent the width direction of the current collector 110.

[0091] Combination Figure 5It can be seen that the first material layer 121 can be considered as the material layer mainly coated on the current collector 110. In some application scenarios, the energy density of the first material can be relatively high to increase the energy capacity of the battery cell including the electrode plate. Of course, the kinetic performance of the first material may also be relatively low.

[0092] The area where the first material layer 121 is located is marked as A. The second material layer 122 may be arranged on both sides of the first material layer 121 in the width direction of the current collector 110, and the areas where the second material layer 122 is located are marked as B and C respectively. The third material layer 123 may be arranged on both sides of the first material layer 121 in the length direction of the current collector 110, and the areas where the third material layer 123 is located are marked as D and E respectively.

[0093] The materials of the material layers coated in the five regions A, B, C, D and E are recorded as material A, material B, material C, material D and material E. Material A corresponds to the first material, material B and material C correspond to the second material, and material D and material E correspond to the materials of the third material layer 123, respectively, and are recorded as third materials.

[0094] The kinetic properties of the second material are higher than those of the first material, that is, the kinetic properties of material B and material C are higher than those of material A, so as to effectively avoid lithium deposition on both sides of the first material layer 121 in the W direction.

[0095] Similarly, the kinetic properties of the third material are higher than those of the first material, that is, the kinetic properties of material D and material E are higher than those of material A, so as to effectively avoid lithium deposition on both sides of the first material layer 121 in the L direction.

[0096] As for the relative performance relationship between material D and material E, no limitation is imposed here, that is, the dynamic performance of material D may be higher than, equal to, or lower than the dynamic performance of material E, and the material types of material D and material E may be the same or different.

[0097] Of course, in practical applications, in the length direction of the current collector 110 , the third material layer 123 may also be disposed on one side of the first material layer 121 .

[0098] In this embodiment, the setting of the third material layer 123 can further set the material layer with higher dynamic performance in the area where lithium deposition may occur, thereby effectively avoiding the occurrence of lithium deposition in the electrode plate; in addition, it also helps to improve the charging efficiency of the battery cell including the electrode plate.

[0099] Optionally, the current collector 110 includes a single-sided region and a double-sided region that are arranged opposite to each other in the length direction;

[0100] Both sides of the double-sided area in the thickness direction are coated with a first material layer 121 and a second material layer 122; one side of the single-sided area in the thickness direction is coated with a fourth material layer 124;

[0101] The dynamic performance of the material of the fourth material layer 124 is higher than the dynamic performance of the first material.

[0102] In combination with some application scenarios, the electrode sheet may need to be wound in the process of making a battery cell. As shown above, both sides of the current collector 110 in the thickness direction may be coated with material layers. During the winding process of the electrode sheet, the material layers on both sides will have a difference in winding radius, that is, the length of the material layer on the outer side of the current collector 110 is greater than the length of the material layer on the inner side of the current collector 110.

[0103] Therefore, generally speaking, the length of the material layer on one side of the current collector 110 is greater than the length of the material layer on the other side of the current collector 110 , and at least a portion of the current collector 110 in the length direction is provided with a material layer only on one side.

[0104] like Figure 6 As shown, the area where both sides of the current collector 110 are coated with the material layer can be called a double-sided area (denoted as RD), and the area where only one side of the current collector 110 is coated with the material layer can be called a single-sided area (denoted as RS). Wherein, the direction L can represent the length direction of the current collector 110, and the direction H can represent the thickness direction of the current collector 110 (i.e., the thickness direction of the double-sided area or the thickness direction of the single-sided area).

[0105] Generally speaking, the single-sided region RS may be located at one end of the length direction of the current collector 110; or, there may be multiple single-sided regions RS, and the single-sided regions RS and the double-sided regions RD are alternately arranged in the length direction of the current collector 110. In general, it can be considered that the single-sided region RS and the double-sided region RD are arranged relatively in the length direction of the current collector 110.

[0106] In combination with some application scenarios, during the processing of the electrode sheet, the electrode sheet is usually cold pressed after the coating of the material layer on the current collector 110 is completed. Due to the different thicknesses of the single-side area RS and the double-side area RD, the pressure on the single-side area RS is usually smaller than the pressure on the double-side area RD, resulting in different compression of the material layer in the single-side area RS and the material layer in the double-side area RD.

[0107] Generally speaking, different compaction can also lead to lithium deposition. For example, when both sides of the current collector 110 are coated with the same material layer, lithium deposition may occur in the single-sided area RS and at the junction of the single-sided area RS and the double-sided area RD.

[0108] In this embodiment, in the double-sided region RD of the current collector 110, the first material layer 121 and the second material layer 122 can be disposed on both end surfaces in the thickness direction of the current collector 110 in the manner described in the above embodiment. In the single-sided region RS of the current collector 110, a fourth material layer 124 can be disposed on one end surface in the thickness direction.

[0109] The kinetic properties of the material of the fourth material layer 124 are higher than those of the first material. That is, the fourth material layer 124 can be made of a material with higher kinetic properties, thereby effectively avoiding lithium deposition in the single-side region RS and increasing the service life of the electrode plate.

[0110] Of course, in order to further and more effectively avoid lithium deposition at the interface between the single-sided region RS and the double-sided region RD, the fourth material layer 124 may also be partially coated onto the double-sided region RD of the current collector 110 .

[0111] Figure 7 and Figure 8 1 is an example diagram of the location area of ​​the fourth material layer 124 on the current collector 110 . The direction L may represent the length direction of the current collector 110 , and the direction W may represent the width direction of the current collector 110 .

[0112] As shown above, the single-sided region RS may be located at one end of the length direction of the current collector 110 ; or, there may be multiple single-sided regions RS, and the single-sided regions RS and the double-sided regions RD are alternately arranged in the length direction of the current collector 110 .

[0113] Figure 7 The diagram shows an example of the location of the fourth material layer 124 when the single-sided region RS is located at one end of the length direction of the current collector 110. It can be seen that the fourth material layer 124 can be located at one end of the length direction of the current collector 110.

[0114] Figure 8 The diagram shows an example of the location of the fourth material layer 124 when the single-sided region RS and the double-sided region RD are alternately arranged in the length direction of the current collector 110. It can be seen that the fourth material layer 124 can be located in the middle of the length direction of the current collector 110.

[0115] Of course, in practical applications, the coating position of the fourth material layer 124 may also be selected according to the distribution of the single-sided area RS and the double-sided area RD on the current collector 110 , which will not be described one by one here.

[0116] The present application also provides a method for manufacturing an electrode plate. Fig. 9 As shown, the method includes:

[0117] Step 901, providing a current collector, wherein one side surface of the current collector includes a first region and a second region, and in a width direction of the current collector, the second region is located on at least one side of the first region;

[0118] Step 902, spraying a first material on a first region and spraying a second material on a second region to obtain an electrode sheet;

[0119] The dynamic performance of the second material is higher than that of the first material.

[0120] In the related art, the area to be sprayed on the current collector is usually regarded as a whole, and during the spraying process, one material is sprayed on the whole area at one time.

[0121] Based on the existing spraying method, if only one material is sprayed on the current collector, it is difficult to balance the needs of electric energy capacity and avoiding lithium plating; if multiple materials are sprayed on the current collector, it is usually necessary to spray one material before spraying another material, and the production efficiency of the electrode plate is low.

[0122] In this embodiment, one side surface of the current collector may include a first region and a second region. In other words, the first region and the second region may be located on the same surface of the current collector. Meanwhile, in the width direction of the current collector, the second region is located on at least one side of the first region.

[0123] The first area and the second area can be considered as areas on the current collector to be sprayed, wherein the first material can be sprayed on the first area, and the second material can be sprayed on the second area, and the kinetic properties of the second material are higher than those of the first material.

[0124] In other words, in this embodiment, there can be multiple areas on the current collector for spraying different materials, rather than treating the area for spraying materials as a whole. In this way, on the one hand, at least two materials with different dynamic properties can be sprayed on the current collector to balance the needs of electric energy capacity and avoiding lithium deposition; on the other hand, different materials can be sprayed on the current collector simultaneously as needed to improve the production efficiency of the electrode sheet.

[0125] In one example, the energy density of the first material may be greater than the energy density of the second material. In other words, the first material may be a material with a greater energy density, thereby helping to increase the energy capacity of the battery cell including the electrode plate.

[0126] Generally speaking, materials with higher energy density tend to have relatively lower dynamic performance. When the first material is used alone, it is easy to cause Figure 1 Lithium deposition occurs at the location shown.

[0127] Therefore, in this embodiment, while spraying the first material on the first region of the current collector, the second material can be sprayed on the second region of the current collector. In the width direction of the current collector, the second region is located on at least one side of the first region.

[0128] If it is defined that the first material is sprayed on the first area to form a first material layer, and the second material is sprayed on the second area to form a second material layer, then the second material layer can be considered to be located in the edge area of ​​the first material layer where lithium deposition is prone to occur. Since the second material has higher kinetic properties and stronger lithium ion diffusion ability, it can effectively avoid lithium ion deposition, thereby effectively avoiding lithium deposition in the above edge areas.

[0129] In summary, it can be seen that the electrode plate manufactured by the electrode plate manufacturing method provided in the embodiment of the present application can effectively balance the needs between electric energy capacity and avoiding lithium plating.

[0130] As for the specific structure of the electrode plate produced, please refer to Figure 2 , Figure 3 Of course, in practical applications, further processing based on the electrode plate can also obtain Figures 4 to 8 The electrode plates shown in the related embodiments are not described in detail here.

[0131] Optionally, spraying the first material in the first area and spraying the second material in the second area are performed simultaneously.

[0132] For ease of understanding, the following mainly uses the production Figure 2 The process of the electrode piece shown is illustrated by way of example.

[0133] like Fig.10 As shown, Fig.10 Made for use with production equipment Figure 2 The schematic diagram of the electrode plate shown in FIG. 1 may include three coating ports, which are respectively referred to as coating port A, coating port B and coating port C, and are used to spray material A, material B and material C respectively.

[0134] Among them, material A may correspond to the first material mentioned above, and material B and material C may correspond to the second material mentioned above. That is to say, the dynamic performance of material B and the dynamic performance of material C may both be higher than the dynamic performance of material A, and the relative performance relationship between material B and material C is not specifically limited here.

[0135] The current collector 200 includes a first region 210 and a second region, wherein the second region may specifically include a first sub-region 221 and a second sub-region 222 , and the first sub-region 221 and the second sub-region 222 are respectively located on both sides of the width direction (denoted as direction W) of the first region 210 .

[0136] When performing the spraying operation shown in step 902, the first sub-region 221, the first region 210, and the second region may respectively face the coating port A, the coating port B, and the coating port C. During the movement of the current collector 200 in the length direction (denoted as direction L) relative to each coating port, each coating port may simultaneously spray material into the corresponding region on the current collector 200 to form a corresponding material layer on the current collector 200.

[0137] Of course, the simultaneous spraying of materials at each coating port described here can be understood as the simultaneous processing of the first material layer and the second material layer on the current collector 200. In practical applications, one or more coating ports can be selectively opened or closed according to the distribution of the first region 210 and the second region on the current collector 200. For example, when the current collector 200 needs to be provided with Figure 8 When the coating port A passes through the region on the current collector 200 corresponding to the fourth material layer, the coating port A may be closed.

[0138] In addition, the current collector 200 moves relative to each coating port along its length direction. The current collector 200 may move actively, or each coating port may move actively, or the current collector 200 and the coating port may move toward each other simultaneously, etc., which is not specifically limited here.

[0139] In one example, if the spraying widths corresponding to coating port A, coating port B and coating port C are recorded as W_A, W_B and W_C respectively, W_A>W_B and W_A>W_C can be set. While avoiding lithium deposition at the edge of the formed first material layer, as much first material with high energy density as possible is sprayed to increase the energy capacity of the battery cell including the prepared electrode plate.

[0140] The above examples are for processing Figure 2 When the electrode sheet shown in FIG. 1 is used, the electrode sheet manufacturing equipment used is the description of the manufacturing process. In practical applications, when processing is required, Figure 3 When the electrode sheet shown or other similar electrode sheets are used, the number or position of the coating ports in the electrode sheet manufacturing equipment can be adjusted as needed. But in general, multiple coating ports can be arranged in sequence along the width direction of the current collector to be sprayed, so that the first material is sprayed in the first area and the second material is sprayed in the second area simultaneously, thereby improving the processing efficiency of the electrode sheet.

[0141] The present application also provides a battery cell, including a positive electrode sheet 310, a negative electrode sheet 320 and a separator 330. Fig.11 As shown, the positive electrode sheet 310 and the negative electrode sheet 320 are respectively connected to the two sides of the thickness direction of the separator 330;

[0142] The negative electrode plate 320 is the above-mentioned electrode plate.

[0143] In other words, in the battery cell provided in this embodiment, the negative electrode sheet 320 may include a current collector, and a first material layer 322 and a second material layer 323 coated on the current collector; in the width direction of the current collector, the second material layer 323 is disposed on at least one side of the first material layer 322;

[0144] The dynamic performance of the second material is higher than that of the first material; the first material is the material of the first material layer 322 , and the second material is the material of the second material layer 323 .

[0145] Among them, Fig.11 As shown, the thickness direction of the separator 330 can be consistent with the thickness direction of the current collector, which can be represented by direction H; the width direction of the current collector can be considered to be the direction perpendicular to the paper surface; in addition, the length direction of the current collector can be represented by direction L.

[0146] It should be noted that the implementation method of the above-mentioned electrode plate embodiment is also applicable to the embodiment of the battery cell and can achieve the same technical effect, which will not be repeated here.

[0147] In some examples, the battery cell can be applied to electronic devices, such as mobile phones, tablet computers, laptop computers, PDAs, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPC), netbooks or personal digital assistants (PDA), etc.

[0148] Of course, in other examples, the above-mentioned battery cells can also be applied to electrical equipment such as vehicles and robots, which are not listed here one by one.

[0149] Optionally, the vertical projection of the first end 311 of the positive electrode sheet 310 on the diaphragm 330 is located in the vertical projection of the second material layer 323 of the negative electrode sheet 320 on the diaphragm 330; the first end 311 is at least one end of the positive electrode sheet 310 in the width direction.

[0150] As shown above, the electrode sheets in the battery cell may be in a wound state, and accordingly, in such a battery cell, the positive electrode sheet 310, the negative electrode sheet 320 and the separator 330 may all be in a wound state. In this embodiment, the vertical projection of the positive electrode sheet 310 and the negative electrode sheet 320 on the separator 330 can be understood as a vertical projection in a flattened state to a certain extent.

[0151] Alternatively, in the wound state, in the length direction of the electrode sheet, the positive electrode sheet 310 and the negative electrode sheet 320 and the separator 330 therebetween can be considered to have a one-to-one correspondence. The vertical projection of the electrode sheet on the separator can be considered to be the projection of the electrode sheet on the corresponding separator 330 along the normal direction of the corresponding separator 330.

[0152] To simplify the description, the length direction of the electrode plate may be recorded as direction L, the width direction of the electrode plate may be recorded as direction W, and the thickness direction of the electrode plate may be recorded as direction H.

[0153] Generally speaking, the width of the negative electrode sheet 320 may be greater than the width of the positive electrode sheet 310 , and the vertical projection of the negative electrode sheet 320 on the separator 330 may cover the vertical projection of the positive electrode sheet 310 on the separator 330 .

[0154] like Fig.12 As shown, in one example, the first end 311 of the positive electrode plate 310 may refer to two ends in the direction W, and the second material layer 323 of the negative electrode plate 320 may be located in two regions, region B and region C in the figure.

[0155] On the side where region B is located, the width of the negative electrode plate 320 exceeding the positive electrode plate 310 can be recorded as ΔWB, and the width of region B can be recorded as W_B, then the following relationship W_B≥ΔWB can exist, so that the vertical projection of the corresponding end of the positive electrode plate 310 on the side of region B on the diaphragm 330 can fall into the vertical projection of region B on the diaphragm 330.

[0156] Similarly, on the side where region C is located, the width of the negative electrode sheet 320 exceeding the positive electrode sheet 310 can be recorded as ΔWC, and the width of region C can be recorded as W_C, then the following relationship W_C≥ΔWC can exist, so that the vertical projection of the corresponding end of the positive electrode sheet 310 on the side of region C on the diaphragm 330 can fall into the vertical projection of region C on the diaphragm 330.

[0157] As shown above, the second material used in the second material layer 323 can have high dynamic performance. In the vertical projection of the separator 330, the area where the second material layer 323 is located covers the first end 311 of the positive electrode plate 310, which can effectively prevent lithium deposition from occurring in the area corresponding to the first end 311 of the negative electrode plate 320, thereby improving the service life of the battery cell.

[0158] Of course, combined Figure 3 , the second material layer 323 may also be located only in the above-mentioned region B or region C, and accordingly, the first end 311 of the positive electrode sheet 310 may refer to the end on the same side as the second material layer 323 in the direction W. Alternatively, the second material layer 323 may be located in the above-mentioned region B and region C, but the first end 311 of the positive electrode sheet 310 may refer to any end in the direction W, and so on.

[0159] Optionally, the negative electrode plate 320 further includes a third material layer 324;

[0160] The vertical projection of the second end 312 of the positive electrode sheet 310 on the diaphragm 330 is located in the vertical projection of the third material layer 324 on the diaphragm 330 ; the second end 312 is at least one end of the positive electrode sheet 310 in the length direction.

[0161] Generally speaking, the length of the negative electrode sheet 320 may be greater than the length of the positive electrode sheet 310 , and the vertical projection of the negative electrode sheet 320 on the diaphragm 330 may cover the vertical projection of the positive electrode sheet 310 on the diaphragm 330 .

[0162] Combination Fig.13 The third material layer 324 may be located in the region D and the region E shown in the figure, and the second end portion 312 may be two ends of the positive electrode sheet 310 in the length direction.

[0163] On the side where region D is located, the length of the negative electrode plate 320 exceeding the positive electrode plate 310 can be recorded as ΔLD, and the length of region D can be recorded as L_D, then the following relationship L_D≥ΔLD can exist, so that the vertical projection of the corresponding end of the positive electrode plate 310 on the side of region D on the diaphragm 330 can fall into the vertical projection of region D on the diaphragm 330.

[0164] Similarly, on the side where region E is located, the length of the negative electrode plate 320 exceeding the positive electrode plate 310 can be recorded as ΔLE, and the length of region E can be recorded as L_E, then the following relationship L_E≥ΔLE can exist, so that the vertical projection of the corresponding end of the positive electrode plate 310 on the side of region E on the diaphragm 330 can fall into the vertical projection of region E on the diaphragm 330.

[0165] Similar to the previous embodiment, this embodiment can effectively prevent lithium deposition from occurring in the area of ​​the negative electrode sheet 320 corresponding to the second end 312 , thereby increasing the service life of the battery cell.

[0166] Of course, in practical applications, the second end 312 of the positive electrode sheet 310 may also refer to any end in the direction L, which will not be elaborated here.

[0167] Optionally, the battery cell further includes a negative electrode tab 340, and the negative electrode tab 340 is connected to the third region of the first current collector 321, and the first current collector 321 is a current collector included in the negative electrode sheet 320;

[0168] When the third region is adjacent to the first region, a fifth material layer 325 is coated on a region of the third region close to the first region;

[0169] The first region is a region on the first current collector 321 coated with the first material layer 322 ; the dynamic performance of the material of the fifth material layer 325 is higher than the dynamic performance of the first material.

[0170] The negative electrode tab 340 may be a current collector electrically connected to the negative electrode plate 320 , that is, the first current collector 321 mentioned above, and the area of ​​the first current collector 321 used to connect to the negative electrode tab 340 may correspond to the third area (marked as R3 in the figure).

[0171] Generally speaking, the length direction of the negative electrode tab 340 may be consistent with the width direction of the negative electrode plate 320 . Therefore, in the direction W, the third region for connecting the negative electrode tab 340 may reach within the width range of the first region (marked as R1 in the figure).

[0172] The first region is coated with a first material layer 322 . Relatively speaking, the first material layer 322 has relatively low dynamic performance. If the first material layer 322 is directly adjacent to the third region, lithium deposition is likely to occur in the adjacent region.

[0173] Therefore, if Fig.14 As shown, in this embodiment, when the third region R3 is adjacent to the first region R1, a fifth material layer 325 is coated in the region of the third region R3 close to the first region R1. The kinetic properties of the material of the fifth material layer 325 are higher than those of the first material, thereby effectively avoiding lithium deposition in the adjacent region of the third region R3 and the first region R1, and improving the service life of the battery cell.

[0174] Optionally, the battery cell further includes a positive electrode adhesive 350 , and the positive electrode adhesive 350 is connected to the fourth region of the first current collector 321 ;

[0175] When the fourth region is adjacent to the first region, a sixth material layer 326 is coated on a region of the fourth region close to the first region;

[0176] The dynamic performance of the material of the sixth material layer 326 is higher than the dynamic performance of the first material.

[0177] The current collector included in the positive electrode sheet 310 is defined as a second current collector. Generally speaking, the positive electrode tab is connected to the second current collector, and the positive electrode adhesive 350 is usually arranged at a position corresponding to the positive electrode tab on the first current collector 321.

[0178] The positive electrode sheet 310 may be specifically connected to the fourth region (marked as R4 in the figure) of the first current collector 321. Similar to the third region R3, the fourth region R4 may also be adjacent to the first region R1 coated with the first material layer 322. The adjacent region is prone to lithium deposition.

[0179] Therefore, if Fig.14 As shown, in this embodiment, when the fourth region R4 is adjacent to the first region R1, the region of the fourth region R4 close to the first region R1 is coated with a sixth material layer 326. The kinetic properties of the material of the sixth material layer 326 are higher than those of the first material, thereby effectively avoiding lithium deposition in the adjacent region of the fourth region R4 and the first region R1, and improving the service life of the battery cell.

[0180] It is worth noting that the second material, the material of the third material layer 324 , the material of the fifth material layer 325 , and the material of the sixth material layer 326 may be the same or different, which is not specifically limited here.

[0181] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0182] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An electrode plate, It is characterized in that include: A current collector, and a first material layer and a second material layer disposed on the same side of the current collector; In the width direction of the current collector, the second material layer is disposed on at least one side of the first material layer; The second material has a higher kinetic property than the first material; the first material is the material of the first material layer, the second material is the material of the second material layer, and the energy density of the first material is greater than the energy density of the second material; The current collector comprises a plurality of single-sided regions and a plurality of double-sided regions, wherein the plurality of single-sided regions and the plurality of double-sided regions are alternately arranged in the length direction of the current collector, the double-sided regions are regions coated with a material layer on both sides of the current collector, and the single-sided regions are regions coated with the material layer only on one side of the current collector; The first material layer and the second material layer are provided on both sides of the double-sided area in the thickness direction; a fourth material layer is provided on one side of the single-sided area in the thickness direction, and in order to avoid lithium deposition at the junction of the single-sided area and the double-sided area, the fourth material layer is partially coated on the double-sided area of ​​the current collector; The dynamic properties of the material of the fourth material layer are higher than the dynamic properties of the first material; The electrode plate further comprises a third material layer disposed on the current collector; in the length direction of the current collector, the third material layer is disposed on at least one side of the first material layer; The dynamic performance of the material of the third material layer is higher than the dynamic performance of the first material.

2. The electrode sheet according to claim 1, It is characterized in that The second material layer includes a first sub-material layer and a second sub-material layer; the first sub-material layer and the second sub-material layer are respectively arranged on both sides of the first material layer, The material of the first sub-material layer is the same as or different from the material of the second sub-material layer.

3. A method for manufacturing an electrode plate, It is characterized in that include: A current collector is provided, wherein a surface of one side of the current collector comprises a first region and a second region, and in a width direction of the current collector, the second region is located on at least one side of the first region; Spraying a first material on the first region through a coating port, and simultaneously spraying a second material on the second region, to obtain the electrode sheet according to any one of claims 1 to 2, wherein the coating ports are arranged sequentially along the width direction of the current collector; Wherein, the dynamic performance of the second material is higher than the dynamic performance of the first material.

4. A battery cell, It is characterized in that It includes a positive electrode sheet, a negative electrode sheet and a separator, wherein the positive electrode sheet and the negative electrode sheet are respectively connected to two sides of the separator in the thickness direction; The negative electrode plate is the electrode plate according to any one of claims 1 to 2.

5. The battery cell according to claim 4, It is characterized in that The vertical projection of the first end of the positive electrode sheet on the diaphragm is located in the vertical projection of the second material layer of the negative electrode sheet on the diaphragm; the first end is at least one end of the positive electrode sheet in the width direction.

6. The battery cell according to claim 4, It is characterized in that The negative electrode plate further includes a third material layer; The vertical projection of the second end of the positive electrode sheet on the diaphragm is located in the vertical projection of the third material layer on the diaphragm; the second end is at least one end of the positive electrode sheet in the length direction.

7. The battery cell according to claim 4, It is characterized in that The battery cell further includes a negative electrode tab, wherein the negative electrode tab is connected to the third region of the first current collector, and the first current collector is the current collector included in the negative electrode plate; In the case where the third region is adjacent to the first region, a fifth material layer is provided in a region of the third region close to the first region; The first region is a region on the first current collector where a first material layer is provided; and the dynamic performance of the material of the fifth material layer is higher than the dynamic performance of the first material.

8. The battery cell according to claim 4, It is characterized in that The battery cell further includes a positive electrode adhesive, wherein the positive electrode adhesive is connected to the fourth region of the first current collector; In the case where the fourth region is adjacent to the first region, a sixth material layer is provided in a region of the fourth region close to the first region; The dynamic performance of the material of the sixth material layer is higher than the dynamic performance of the first material.

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