Battery electrode plate, electrode assembly, battery cell, battery, and power consumption device

Abstract

To provide a battery electrode plate, an electrode assembly, a battery cell, a battery, and a power consumption device in which an active material layer and an insulating layer coated on the battery electrode plate form a clear boundary, thereby improving the product yield.SOLUTION: The present application relates to a battery electrode plate, an electrode assembly, a battery cell, a battery, and a power consumption device. The battery electrode plate includes a current collector, at least one surface of the current collector comprises a coated region and an uncoated region connected to each other. An active material layer and an insulating layer are coated on the coated region. The insulating layer is located on a side closer to the uncoated region of the active material layer. Here, the insulating layer comprises a first portion and a second portion connected to each other. The second portion is located in an edge region of the insulating layer closer to the active material layer. The active material layer is configured to cover the second portion, such that the active material layer and the insulating layer partially overlap along a thickness direction of the electrode plate.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present application relates to the technical field of energy storage devices, and in particular to battery plates, electrode assemblies, battery cells, batteries, and power consuming devices. [Background technology]

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, battery-powered vehicles, electric cars, electric airplanes, electric steamships, electric toy cars, electric toy steamships, electric toy airplanes, power tools, etc. Battery cells may include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, etc.

[0003] During the use of battery cells, lithium deposition often occurs in battery cells, which can penetrate the separator and cause a short circuit, posing a safety risk. Therefore, the lithium deposition problem in battery cells needs to be resolved as soon as possible. Summary of the Invention

[0004] To solve the above problems, the present application provides a battery plate, an electrode assembly, a battery cell, a battery, and a power consumption device, in which the active material layer and the insulating layer applied to the battery plate form a clear boundary, reducing the risk of lithium deposition and improving product yield.

[0005] According to a first aspect of the present application, there is provided a battery plate, the battery plate including a current collector, at least one surface of the current collector including a coated area and an uncoated area that are connected to each other, an active material layer and an insulating layer that are coated on the coated area, the insulating layer being located closer to the uncoated area of the active material layer, the insulating layer including a first portion and a second portion that are connected to each other, the second portion being located at an edge area of the insulating layer that is closer to the active material layer, the active material layer covering the second portion but not the first portion, such that the active material layer and the insulating layer partially overlap along the thickness direction of the plate.

[0006] The second portion is covered by the active material layer, and the second portion does not penetrate into the upper surface of the active material layer. This reduces the problem of blurred boundaries due to mixing of coating slurries in the edge region of the insulating layer closer to the active material layer, thereby forming clear boundaries and reducing the problem of lithium deposition due to incorrect determination of the boundaries of the active material layer resulting in the dimensions of the positive and negative plate active material layers not meeting requirements.

[0007] In some embodiments, the thickness of the insulating layer is equal to or less than the thickness of the active material layer.

[0008] There is a difference in thickness between the active material layer and the insulating layer, which reduces the risk of the active material layer and insulating layer slurries mixing and penetrating into the upper surface of the active material layer.

[0009] In some embodiments, the thickness of the second portion is less than or equal to the thickness of the first portion.

[0010] The thickness of the insulating layer is small, and the total coating thickness in the overlapping region between the active material layer and the second portion is significantly increased, thereby reducing the problem of forming edge bulges and improving the overall thickness consistency of the battery plate.

[0011] In some embodiments, the shortest distance along the thickness direction between the surface of the second portion facing the current collector and the surface of the current collector is 0 to 90 μm.

[0012] In some embodiments, the surface of the second portion facing away from the current collector is inclined, and the inclined surface gradually approaches the current collector along the direction extending from the first portion to the active material layer.

[0013] The surface of the second portion facing away from the current collector is beveled, which reduces the risk of forming bulges at the edges due to an increase in the total coating thickness in the overlapping region between the active material layer and the second portion. Furthermore, as the coating dries, the active material layer shrinks and slips along the beveled surface, reducing penetration and mixing of the coating slurry of the second portion into the active material layer.

[0014] In some embodiments, the distance between the surface of the second portion away from the current collector and the outer surface of the active material layer along the thickness direction of the electrode plate is 20 μm or more.

[0015] The distance between the surface of the second portion away from the current collector and the outer surface of the active material layer can be set so that the second portion is sufficiently separated from the outer surface of the active material layer, thereby reducing the possibility that the coating slurry of the second portion will penetrate into the outer surface of the active material layer.

[0016] In some embodiments, the maximum thickness of the second portion is between 3 and 90 μm.

[0017] By setting the thickness of the second portion relatively small, the change in coating thickness in the overlapping region between the active material layer and the second portion is also relatively small, and the coating thickness in the overlapping region between the active material layer and the insulating layer does not increase significantly, resulting in the formation of a bulge at the edge.

[0018] In some embodiments, the width of the second portion is equal to or smaller than the width of the first portion along the alignment direction of the active material layer and the insulating layer.

[0019] By setting the width of the first portion and the width of the second portion, it is possible to prevent the overlap width between the second portion and the active material layer from being too wide.

[0020] According to a second aspect of the present application, there is provided an electrode assembly including the battery plate described above.

[0021] According to a third aspect of the present application, there is provided a battery cell including the electrode assembly described above.

[0022] According to a fourth aspect of the present application, there is provided a battery including a plurality of the above-described battery cells.

[0023] According to a fifth aspect of the present application, there is provided a power consumption device, characterized in that it includes the battery described above, the battery being adapted to supply electrical energy.

[0024] It is to be understood that both the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. [Brief explanation of the drawings]

[0025] In order to more clearly explain the technical solutions in the embodiments of the present application, the following briefly describes the drawings used in the embodiments of the present application. It should be apparent that the drawings described below are only specific embodiments of the present application, and those skilled in the art can obtain other embodiments based on the following drawings without making any creative efforts. [Figure 1] 1 is a structural schematic diagram of a specific embodiment of a power consumption device according to the present application; [Figure 2] 1 is an exploded schematic view of a battery according to some embodiments of the present application. [Figure 3] FIG. 1 is an exploded schematic view of a battery cell according to some embodiments of the present application. [Figure 4] 1 is a cross-sectional schematic view of an electrode assembly according to one specific embodiment of the present application. [Figure 5] FIG. 5 is a partial schematic view of an E-E cross section of the electrode assembly in FIG. 4. [Figure 6] 1 is a comparative diagram of local development of a positive electrode plate and a negative electrode plate according to some embodiments of the present application. FIG. [Figure 7] FIG. 2 is a cross-sectional view of one embodiment of a battery plate. [Figure 8] FIG. 8 is an enlarged view of part I in FIG. [Figure 9] FIG. 4 is a cross-sectional view of another embodiment of a battery plate. [Figure 10] FIG. 10 is a cross-sectional view of yet another embodiment of a battery plate.

[0026] The drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification serve to explain the principles of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0027] In order to better understand the technical solution of the present application, the following detailed description of the embodiments of the present application is provided in conjunction with the drawings.

[0028] It should be noted that the described embodiments are only some of the embodiments of the present application, but not all of the embodiments, and all other embodiments that can be obtained by a person skilled in the art based on the embodiments of the present application without any creative work fall within the scope of protection of the present application.

[0029] The terms used in the examples of this application are merely for the purpose of describing particular examples and are not intended to limit the application. As used in the examples of this application and the appended claims, the singular forms "a," "the," and "the" are intended to include the plural forms, except where the context clearly dictates otherwise.

[0030] It should be understood that the term "and / or" in this application merely describes the relationship between related objects and indicates that three relationships may exist, for example, A and / or B may represent three cases: A alone, A and B in combination, and B alone. Also, the character " / " in the text generally indicates that the related objects before and after are in an "or" relationship.

[0031] It should be noted that the orientation terms "up," "down," "left," "right," etc. described in the embodiments of the present application are described in terms of angles shown in the drawings and should not be understood as limiting the embodiments of the present application. It should be further understood that, in context, when an element is referred to as being connected "up" or "down" to another element, it can be connected not only directly to the "up" or "down" of the other element, but also to the "up" or "down" of the other element via an intermediate element.

[0032] The battery referred to in the embodiments of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. The battery generally includes a housing for packaging one or more battery cells. The housing can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0033] A battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode plate, a negative electrode plate, and a separator. The battery cell operates mainly by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer, and the positive electrode active material layer is applied to the surface of the positive electrode current collector. The positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer applied, and the positive electrode current collector without the positive electrode active material layer is referred to as a positive electrode tab. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is applied to the surface of the negative electrode current collector. The negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer applied, and the negative electrode current collector without the negative electrode active material layer is referred to as a negative electrode tab. To prevent melting even when a large current is passed through the electrodes, a plurality of positive electrode tabs are stacked, and a plurality of negative electrode tabs are stacked.

[0034] In the prior art, active material layers and insulating layers are generally applied to the current collectors of battery cell electrodes, but the colors of the active material layers and insulating layers do not match. After application is complete, the boundary between the active material layers and insulating layers must be visually identified to determine the width of the active material layer.

[0035] The applicant has discovered that when the active material layer and the insulating layer are applied simultaneously, interpenetration and mixing occur at the boundary between the active material layer and the insulating layer as they dry, and the insulating layer penetrates into the surface of the active material layer, ultimately causing blurring of the boundary line between the active material layer and the insulating layer after drying.

[0036] In a battery cell, it is required that the active material of the negative plate covers the active material of the positive plate, i.e., the active material layer of the negative plate is required to be wider than the active material layer of the positive plate to avoid the problem of lithium deposition. During the drying process of the active material layer and the insulating layer, interpenetration and mixing occur, resulting in a blurred boundary, which causes inconsistency in determining the position of the active material layer, and may result in a situation where the positive plate in the electrode assembly is not completely covered by the negative plate, which will cause lithium deposition at that position in the battery cell and affect the performance of the battery cell.

[0037] Based on the above problems discovered by the applicant, the applicant has improved the coating structure of the active material layer and the insulating layer applied to the battery plate, and solved the above problems by partially overlapping the active material layer and the insulating layer. The following is a further description of the examples of the present application.

[0038] FIG. 1 is a structural schematic diagram of a specific embodiment of a power consumption device according to the present application.

[0039] As shown in Figure 1, an embodiment of the present application provides a battery B and a power consumption device that uses the battery B as a power source. The power consumption device that uses the battery B as a power source includes equipment such as a vehicle A, a boat, or a small airplane, and the device employs the battery B to provide electrical energy and generate a driving force for driving the device. The device may also use electrical energy and other types of energy (e.g., fossil energy) simultaneously to generate a driving force. Any device that can use the battery B as a power source falls within the scope of protection of the present application.

[0040] As shown in Figure 1, vehicle A is taken as an example of a power consumption device. In the embodiments of the present application, vehicle A may be a new energy vehicle, which may be a pure electric vehicle, a hybrid vehicle, a range extender vehicle, etc. For example, vehicle A includes a motor M, a controller C, and a battery B. Battery B is horizontally installed at the bottom of the vehicle body, and controller C controls battery B to supply power to motor M, which is connected to wheels on the vehicle body via a transmission mechanism to drive vehicle A.

[0041] To meet various power consumption needs, battery B may include multiple battery cells D, where the multiple battery cells D may be connected in series, parallel, or series-parallel, with series-parallel connection referring to a mixture of series and parallel connections. Battery B may also be called a battery pack. Optionally, multiple battery cells D may first be connected in series, parallel, or series-parallel to form a battery module, and multiple battery modules may be connected in series, parallel, or series-parallel to form battery B. That is, multiple battery cells D may directly form battery B, or may first form a battery module, which may then form battery B.

[0042] FIG. 2 is an exploded schematic view of Battery B according to some embodiments of the present application.

[0043] 2, the battery B includes a housing F and a battery cell D housed within the housing F. The housing F may have various shapes, such as a cylindrical body or a rectangular parallelepiped. Of course, the housing F may have various structures.

[0044] In some embodiments, the housing F may include an upper housing F1 and a lower housing F2, which are fitted together to define an accommodating space for accommodating the battery cells D.

[0045] The battery B may have one or more battery cells D. If there are multiple battery cells D, the multiple battery cells D may be connected in series, parallel, or series-parallel, and a series-parallel connection means that the multiple battery cells D may be connected in series or parallel.

[0046] FIG. 3 is an exploded schematic view of a battery cell D according to some embodiments of the present application.

[0047] As shown in FIG. 3 , a battery cell D generally includes an electrode assembly 100, a case 200, and an end cap assembly 300. The end cap assembly 300 fits into an opening in the case 200 to provide a sealed space for the electrode assembly 100 and the electrolyte. The case 200 may have various shapes, such as a cylindrical shape or a rectangular parallelepiped shape. The shape of the case 200 can be determined based on the specific shape of the electrode assembly 100. For example, if the electrode assembly 100 has a cylindrical structure, the case 200 may have a cylindrical structure, and if the electrode assembly 100 has a rectangular parallelepiped structure, the case 200 may have a rectangular parallelepiped structure. As can be appreciated, the shape of the case 200 and the shape of the electrode assembly 100 may be different.

[0048] 3, the case 200 has a hollow rectangular parallelepiped structure with one end open. The case 200 may be made of various materials, such as plastic, copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application are not particularly limited thereto.

[0049] 3, the end cap assembly 300 is used to close the opening of the case 200. When assembling the battery cell D, the electrode assembly 100 is first placed in the case 200, and the electrode assembly 100 and the end cap assembly 300 are electrically connected and fixed, and then both sides of the end cap assembly 300 are fixedly connected to the case 200 to complete the assembly of the battery cell D.

[0050] FIG. 4 is a cross-sectional schematic view of an electrode assembly 100 according to one exemplary embodiment of the present application.

[0051] As shown in FIG. 4, in one specific embodiment of the present application, an electrode assembly 100 is formed by winding a battery plate 1 and a separator 2, where the battery plate 1 includes a positive electrode plate 1a and a negative electrode plate 1b, and the separator 2 is an insulator interposed between the positive electrode plate 1a and the negative electrode plate 1b.

[0052] FIG. 5 is a top-down schematic diagram of an E-E cross section of the electrode assembly 100 in FIG.

[0053] 5, the positive electrode plate 1a includes a positive electrode current collector 11a and a positive electrode active material layer 12a. The positive electrode current collector 11a includes a coated region and an uncoated region. The positive electrode active material layer 12a is coated on the surface of the coated region of the positive electrode current collector 11a. The uncoated region of the positive electrode current collector 11a protrudes from the coated region along the width direction X of the plate to form a positive electrode tab 111a (as shown in FIG. 6). Taking a lithium-ion battery as an example, the material of the positive electrode current collector 11a may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, a ternary lithium, lithium manganese oxide, or the like. Along the thickness direction Z of the electrode plate, the positive electrode active material layer 12a may be applied to only one surface of the positive electrode current collector 11a, or the positive electrode active material layer 12a may be applied to both surfaces of the positive electrode current collector 11a simultaneously. The positive electrode current collector 11a shown in FIG. 5 has the positive electrode active material layer 12a applied to both surfaces simultaneously.

[0054] The negative electrode plate 1b includes a negative electrode current collector 11b and a negative electrode active material layer 12b. The negative electrode current collector 11b includes a coated area and an uncoated area. The negative electrode active material layer 12b is coated on the surface of the negative electrode current collector 11b. Along the width direction X of the plate, the uncoated area of the negative electrode current collector 11b protrudes from the coated area to form a negative electrode tab 111b (as shown in FIG. 6). The material of the negative electrode current collector 11b may be copper, and the negative electrode active material may be carbon or silicon. Along the thickness direction Z of the plate, the negative electrode active material layer 12b may be coated on only one surface of the negative electrode current collector 11b. Alternatively, the positive electrode active material layer 12a may be coated on both surfaces of the negative electrode current collector 11b simultaneously. The negative electrode current collector 11b shown in FIG. 5 has the negative electrode active material layer 12b coated on both surfaces simultaneously.

[0055] FIG. 6 is a comparative diagram of local development of a positive electrode plate 1a and a negative electrode plate 1b according to some embodiments of the present application.

[0056] In some embodiments, the electrode assembly 100 is formed by winding a positive electrode plate 1a, a negative electrode plate 1b, and a separator 2 interposed between the positive electrode plate 1a and the negative electrode plate 1b. After the electrode assembly 100 is unfolded, a laminated structure of the positive electrode plate 1a, the separator 2, and the negative electrode plate 1b is formed. Fig. 6 shows a local schematic diagram of the positive electrode plate 1a and the negative electrode plate 1b in the electrode assembly 100 after unfolding. In order to clearly show the dimensional relationship between the positive electrode plate 1a and the negative electrode plate 1b, Fig. 6 does not show the unfolded separator 2, and a portion of the negative electrode plate 1b has been removed from the right side of the dashed line in the figure to show the dimensional state of the positive electrode plate 1a.

[0057] As shown in Fig. 6, a positive electrode active material layer 12a is applied to the coated area of the positive electrode plate 1a, and the uncoated area forms positive electrode tabs 111a. The positive electrode tabs 111a are spaced apart along the longitudinal direction Y of the electrode plate, and overlap with a plurality of positive electrode tabs 111a when winding the electrode assembly 100. A negative electrode active material layer 12b is applied to the coated area of the negative electrode plate 1b, and the uncoated area forms negative electrode tabs 111b. The negative electrode tabs 111b are spaced apart along the longitudinal direction Y of the electrode plate, and overlap with a plurality of negative electrode tabs 111b when assembling the electrode assembly 100. Fig. 6 does not show the overall lengths of the positive electrode plate 1a and the negative electrode plate 1b, nor does it show all of the positive electrode tabs 111a and the negative electrode tabs 111b.

[0058] Along the width direction X of the electrode plates, the negative electrode active material layer 12b of the negative electrode plate 1b must cover the positive electrode active material layer 12a of the positive electrode plate 1a. That is, the width H1 of the positive electrode active material layer 12a must be smaller than the width H2 of the negative electrode active material layer 1b, so that the positive electrode active material layer 12a and the negative electrode active material layer 1b maintain at least a width difference ΔH. To meet the battery performance requirements, the width difference ΔH generally needs to satisfy the formula 0≦ΔH≦2.5 mm, so that the negative electrode active material layer 12b of the negative electrode plate 1b covers the positive electrode plate active material layer 12a and reduces the risk of lithium deposition problems.

[0059] FIG. 7 is a cross-sectional view of one embodiment of a battery plate 1.

[0060] As shown in FIG. 7, in one specific embodiment, the current collector 11 of the battery plate 1 of the present application has an active material layer 12 and an insulating layer 14 applied to both surfaces along the thickness direction Z of the plate. However, this is just one example, and the active material layer 12 and the insulating layer 14 may be applied to only one surface of the current collector 11.

[0061] In some embodiments, the battery plate 1 includes a current collector 11, at least one side of which includes a connected uncoated area and a coated area. The coated area is coated with an active material layer 12 and an insulating layer 14, and the insulating layer 14 is located closer to the uncoated area of the active material layer 12, with the uncoated area forming a tab 111. The battery plate 1 may be a positive electrode plate 1a or a negative electrode plate 1b. Both the positive electrode plate 1a and the negative electrode plate 1b can be used in the following embodiments. When the battery plate 1 is a positive electrode plate 1a, the current collector 11 is a positive electrode current collector 11a, and the tab 111 is a positive electrode tab 111a. When the battery plate 1 is a negative electrode plate 1b, the current collector 11 is a negative electrode current collector 11b, and the tab 111 is a negative electrode tab 111b.

[0062] As shown in Figure 7, the insulating layer 14 includes a first portion 141 and a second portion 142 that are connected to each other, and the second portion 142 is located in an edge region of the insulating layer 14 that is closer to the active material layer 12. The active material layer 12 is configured to cover the second portion 142 but not the first portion 141, thereby partially overlapping the projections of the active material layer 12 and the insulating layer 14 along the thickness direction Z of the electrode plate.

[0063] The edge of active material layer 12 abuts first portion 141, forming boundary line 15. Second portion 142 is covered by active material layer 12, and second portion 142 does not penetrate into the upper surface of active material layer 12. This prevents the problem of blurred boundary line due to mixing of the coating slurry in the edge region of insulating layer 14 closer to active material layer 12, thereby forming a clear boundary line 15.

[0064] FIG. 8 is an enlarged view of part I in FIG.

[0065] As shown in FIG. 8 , the thickness w1 of the insulating layer 14 along the thickness direction Z of the electrode plate is less than or equal to the thickness w2 of the active material layer 12, i.e., w1≦w2. In this embodiment, the thickness w1 of the insulating layer 14 refers to the maximum thickness of the insulating layer 14. The thickness w2 of the active material layer 12 is preferably in the range of 50 to 400 micrometers (μm), and the thickness w1 of the insulating layer is preferably in the range of 3 to 90 μm. When the active material layer 12 covers the second portion 142, the coating slurry of the second portion 142 comes into contact with the coating slurry inside the active material layer 12. Because there is a large difference in thickness between the thickness w2 of the active material layer 12 and the thickness w1 of the insulating layer 14, even if the coating slurry of the second portion 142 and the coating slurry inside the active material layer 12 mix together, the mixed slurry does not seep out onto the upper surface of the active material layer 12.

[0066] In one specific embodiment, the thickness w4 of the first portion 141 is the maximum thickness of the insulating layer 14, i.e., w4=w1.

[0067] The thickness w3 of the second portion 142 is less than the thickness w4 of the first portion 141, i.e., w3≦w4. The thickness w3 of the second portion 142 is smaller than the thickness w4 of the first portion 141 outside the exposed active material layer 12, and the thinner second portion 142 protrudes into the active material layer 12. Because the thickness w3 of the second portion is small, the coating thickness in the area of the second portion 142 covered by the active material layer 12 does not increase significantly, thereby preventing the formation of edge bulges. This ensures that the overall thickness of the battery plate 1 is consistent, and when the coated battery plate 1 is wound to form a plate winding, the presence of edge bulges in the battery plate 1 reduces the risk of expansion fracture or tearing during winding.

[0068] The range of the shortest distance w5 between the surface of second portion 142 facing current collector 11 and the surface of current collector 11 along thickness direction Z of the electrode plate should satisfy the formula 0≦w5≦0.9×w2, that is, the shortest distance w5 between the surface of second portion 142 facing current collector 11 and the surface of current collector 11 should be 0.9 times or less the thickness w2 of active material layer 12. In one specific embodiment, the shortest distance w5 between inclined surface 1421 of second portion 142 facing current collector 11 and the surface of current collector 11 is 0 to 90 μm.

[0069] The surface of the second portion 142 facing the current collector 11 is the lower surface of the second portion 142 along the thickness direction Z of the electrode plate, and the surface of the second portion 142 facing away from the current collector 11 is the upper surface of the second portion 142 along the thickness direction Z of the electrode plate.

[0070] The second portion 142 extends into the active material layer 12, and the active material layer 12 can cover the upper and lower surfaces of the second portion 142 along the thickness direction Z of the electrode plate, and the end faces of the second portion 142 that extend into the active material layer 12 along the width direction X of the electrode plate. The active material layer 12 may cover only the upper surface and end faces of the second portion 142 along the thickness direction Z of the electrode plate. In this case, the shortest distance w5 between the surface of the second portion 142 facing the current collector 11 and the surface of the current collector 11 is 0, i.e., the surface of the second portion 142 facing the current collector 11 is directly applied to the current collector 11.

[0071] By setting the shortest distance w5 between the surface of second portion 142 facing current collector 11 and the surface of current collector 11, second portion 142 can be ensured to be sufficiently close to current collector 11 and sufficiently far from the outer surface of active material layer 12, thereby reducing the possibility of the coating slurry of second portion 142 penetrating into the outer surface of active material layer 12.

[0072] In some embodiments, the range of the distance w6 between the surface of second portion 142 away from current collector 11 and the outer surface of active material layer 12 along the thickness direction Z of the electrode plate should satisfy the formula 0.01 × w2 ≦ w6 ≦ 0.9 × w2. In one specific embodiment, the distance w6 between the surface of second portion 142 away from current collector 11 and the outer surface of active material layer 12 is 20 μm or more.

[0073] Setting the distance w6 between the surface of the second portion 142 facing away from the current collector 11 and the outer surface of the active material layer 12 ensures that the second portion 142 is sufficiently separated from the outer surface of the active material layer 12, thereby reducing the possibility that the coating slurry of the second portion 142 will penetrate into the outer surface of the active material layer 12.

[0074] In some embodiments, the range of the thickness w3 of the second portion 142 should satisfy the formula 0.01×w2≦w3≦0.9×w2. In one specific embodiment, the thickness w3 of the second portion 142 is 3 to 90 μm.

[0075] By setting the thickness w3 of the second portion 142 relatively small, the change in coating thickness in the overlapping region between the active material layer 12 and the second portion 142 is also relatively small, and the coating thickness in the overlapping region between the active material layer 12 and the insulating layer 14 does not increase significantly, resulting in the formation of edge bulges. This ensures that the overall thickness of the battery plate 1 is consistent, and reduces the risk of edge bulges of the battery plate 1 when winding the electrode assembly 100 around the battery plate 1.

[0076] Generally, the tab 111 is obtained by die-cutting the base material of the battery plate 1. Since the die-cut position of the tab 111 must be located on the insulating layer 14, the insulating layer 14 must have a certain width. In some embodiments, the width L1 of the first portion 141 is in the range of 0.1 to 15 millimeters (mm), thereby ensuring that the die-cut position of the tab 111 is located on the first portion 141.

[0077] Along the arrangement direction of the active material layers 12 and the insulating layers 14 (width direction X of the electrode plate), the width L2 of the second portions 142 is equal to or less than the width L1 of the first portions 141, i.e., L2≦L1. In some embodiments, the width L2 of the second portions 142 is in the range of 0.01 to 2 mm, which ensures that the projections of the active material layers 12 and the second portions 142 in the thickness direction Z of the electrode plate overlap, while also preventing the overlap width between the second portions 142 and the active material layers 12 from being too wide.

[0078] FIG. 9 is a cross-sectional view of another embodiment of the battery plate 1.

[0079] As shown in FIG. 9 , in some embodiments, the surface of the second portion 142 facing away from the current collector 11 is a slope 1421, which gradually approaches the current collector 11 along the direction extending from the first portion 141 to the active material layer 12. In this case, the projection of the active material layer 12 along the thickness direction of the electrode plate overlaps with the second portion 142. The thickness w3 of the second portion 142 gradually decreases from the position where the second portion 142 contacts the first portion 141 in the direction opposite the width direction X of the electrode plate. This increases the total coating thickness in the overlapping region between the active material layer 12 and the second portion 142, thereby reducing the risk of forming bulges at the edges. After the active material layer 12 and the second portion 142 are simultaneously applied, as the coating dries, the active material layer 12 shrinks and slips along the slope 1421, reducing penetration and mixing of the coating slurry from the second portion 142 into the active material layer 12.

[0080] In FIG. 9, the thickness w4 of the first portion 141 along the thickness direction Z of the electrode plate is equal to the thickness w2 of the active material layer, but this is just one example.

[0081] FIG. 10 is a cross-sectional view of another embodiment of a battery plate 1.

[0082] 10 , in some other embodiments, the surface of second portion 142 facing away from current collector 11 is inclined 1421, and the thickness w4 of first portion 141 along thickness direction Z of the electrode plate is smaller than the thickness w2 of the active material layer. In these embodiments, insulating layer 14 has a smaller thickness than active material layer 12, which can reduce the problem of bulging edges caused by a significant increase in coating thickness in the overlapping region between active material layer 12 and insulating layer 14 due to mixing of the coating slurry.

[0083] Of course, the shape of the second portion 142 in the present application is not limited to the situation described in the above embodiments, and it may be a combination of various structural shapes in each embodiment of the present application.

[0084] The battery plate 1 of the present application is coated with an active material layer 12 and an insulating layer 14, and the insulating layer 14 includes a connecting first portion 141 and a second portion 142. The second portion 142 is located in the edge region of the insulating layer 14 closer to the active material layer 12. The active material layer 12 is configured to cover the second portion 142, so that the projections of the active material layer 12 and the insulating layer 14 along the thickness direction Z of the plate partially overlap. The second portion 142 does not penetrate into the upper surface of the active material layer 12. Therefore, in the edge region of the insulating layer 14 closer to the active material layer 12, there is no problem of blurring of the boundary due to mixing of the coating slurry, and a clear boundary line 15 is formed.

[0085] By using the electrode assembly 100 constructed with the battery plate 1 of the present application, the battery cell D, and the battery B, it is possible to ensure that the negative electrode plate 1b covers the positive electrode plate 1a, thereby reducing the risk of lithium deposition in the battery and improving the safety of the battery.

[0086] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Those skilled in the art may make various modifications and variations to the present application. All modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application. [Explanation of symbols]

[0087] A-vehicle B-Battery C-Controller D-battery cell F-chassis F1-Upper housing F2-lower housing M-motor 100-electrode assembly 200-case 300-End Cap Assembly 1-Battery plate 1a-positive electrode plate 1b-Negative plate 11-Current Collector 11a-Positive current collector 11b-Negative electrode current collector 111-Tab 111a-positive electrode tab 111b-negative electrode tab 12-Active material layer 12a-Cathode active material layer 12b-Anode active material layer 14-Insulating layer 141-First part 142-Second Part 15-Border 2-Separator X - width direction of pole plate Y-electrode plate longitudinal direction Z-thickness direction of electrode plate

Claims

1. A battery plate comprising: the battery plate includes a current collector; at least one surface of the current collector includes a coated region and an uncoated region that are connected to each other, an active material layer and an insulating layer are coated on the coated region, and the insulating layer is located on a side of the active material layer that is closer to the uncoated region; wherein the insulating layer includes a first portion and a second portion that are connected to each other, the second portion is located in an edge region of the insulating layer that is closer to the active material layer, and the active material layer is configured to cover the second portion but not the first portion, thereby causing the active material layer and the insulating layer to partially overlap along the thickness direction of the plate.

2. 2. The battery plate of claim 1, wherein the maximum thickness of the insulating layer is equal to or less than the maximum thickness of the active material layer.

3. 10. The battery plate of claim 1, wherein the maximum thickness of the second portion is less than or equal to the maximum thickness of the first portion.

4. 2. The battery plate according to claim 1, wherein the shortest distance between the surface of the second portion facing the current collector and the surface of the current collector along the thickness direction of the plate is 0 to 90 μm.

5. 2. The battery plate according to claim 1, wherein a surface of the second portion facing away from the current collector is an inclined surface, and the inclined surface gradually approaches the current collector along a direction extending from the first portion to the active material layer.

6. 2. The battery plate according to claim 1, wherein the distance between the surface of the second portion away from the current collector and the outer surface of the active material layer along the thickness direction of the plate is 20 μm or more.

7. The battery plate of claim 1 , wherein the second portion has a maximum thickness of 3 to 90 μm.

8. 8. The battery plate according to claim 1, wherein the maximum width of the second portion is equal to or less than the maximum width of the first portion along the arrangement direction of the active material layer and the insulating layer.

9. An electrode assembly comprising a battery plate according to any one of claims 1 to 8.

10. A battery cell comprising the electrode assembly of claim 9.

11. A battery comprising a plurality of battery cells according to claim 10.

12. 12. A power consuming device comprising the battery of claim 11, said battery being adapted to provide electrical energy.

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