Electrode plate, electrode assembly, battery monomer, battery and electric device

Abstract

The utility model relates to an electrode plate, an electrode assembly, a battery monomer, a battery and a power utilization device, and the electrode plate comprises a current collector which comprises a covering part with a three-dimensional grid structure; the covering part is covered with the electrode material part, and part of the electrode material part is embedded into the three-dimensional grid of the covering part. According to the technical scheme, the surface of the covering part is covered with the electrode material part, and the electrode material part is partially embedded into the grid of the covering part, that is, the electrode material part can be partially embedded into the internal grid of the covering part, contact between the electrode material part and the current collector can be increased through the three-dimensional grid, and transmission of current in multiple directions of the electrode plate is enhanced. And moreover, the connection strength between the electrode material part and the current collector is high, so that the electrode material part and the current collector are not easy to fall off, and the reliability of the battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to electrode sheets, electrode assemblies, battery cells, batteries and electrical devices. Background Art

[0002] Traditional electrode sheets are generally prepared by wet method, that is, the electrode slurry is coated on the current collector, and the electrode sheet is obtained through drying and other processes. This method has a long processing cycle, high equipment requirements, high energy consumption, and large equipment space. In order to improve the above defects, the relevant technology adopts dry method preparation, which is to first roll the electrode powder into an electrode film, and then composite the electrode film on the current collector.

[0003] For dry preparation, a binder is often required to ensure the bonding between the electrode film and the current collector. The binder needs to be processed into a fiber shape to support the electrode powder, which is difficult to process and difficult to form, resulting in the electrode film easily falling off the current collector, especially for large-sized electrode sheets, and the yield rate is low. Utility Model Content

[0004] Based on this, it is necessary to provide an electrode sheet, an electrode assembly, a battery cell, a battery and an electrical device to address the problem that electrode powder easily falls off the current collector when preparing electrode sheets by dry method.

[0005] An electrode sheet, comprising:

[0006] A current collector including a covering portion in a three-dimensional grid structure; and

[0007] The electrode material portion is covered on the covering portion, and a portion of the electrode material portion is embedded in the three-dimensional grid of the covering portion.

[0008] In some embodiments, the electrode material portion is rolled and compounded on the covering portion.

[0009] In some embodiments, the maximum particle size D of the active material contained in the electrode material portion is max The average minimum inner diameter R of the three-dimensional grid of the covering portion min , satisfying: R min ≥D max .

[0010] In some embodiments, the median particle size D of the active material contained in the electrode material portion is 50 , satisfying: R min ≥3D 50 and / or,

[0011] The R min Satisfy: 20um≥R min ≥35nm.

[0012] In some embodiments, a coating thickness h of the electrode material portion on the surface of the coating portion satisfies: 0<h≤300 um.

[0013] In some embodiments, the electrode material portion is covered on at least one end of the covering portion in the thickness direction, and the depth of the entire electrode material portion embedded in the covering portion is equal to the thickness of the covering portion.

[0014] In some embodiments, the current collector further includes a pole ear portion, and in the width direction of the current collector, the pole ear portion is disposed adjacent to the covering portion, and a thickness of the pole ear portion is less than a thickness of the covering portion.

[0015] In some embodiments, the electrode material portion is obtained by coating a raw material having an electrode material content of not less than 85% by mass on the coating portion.

[0016] An electrode assembly comprises a diaphragm, a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and / or the negative electrode sheet is the electrode sheet as described in any of the above embodiments, and the diaphragm is arranged between the positive electrode sheet and the negative electrode sheet.

[0017] A battery cell comprises a shell and the electrode assembly described in the above embodiment, wherein the electrode assembly is accommodated in the shell.

[0018] A battery comprises the battery cell as described in the above embodiment.

[0019] An electrical device, characterized in that it comprises the battery as described in the above embodiment, and the battery is used to provide electrical energy.

[0020] In the above-mentioned electrode sheet, electrode assembly, battery cell, battery and electrical device, the electrode material part is covered on the surface of the covering part, and part of it is embedded in the grid of the covering part, that is, part of the electrode material part is embedded in the internal grid of the covering part, and the contact between the electrode material part and the current collector can be increased through the three-dimensional grid, and the current transmission in multiple directions of the electrode sheet can be strengthened. Moreover, the connection strength between the electrode material part and the current collector is strong, and it is not easy for the electrode material part and the current collector to fall off, which helps to improve the reliability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0022] Figure 1 Schematic diagram of the appearance of electrode sheets according to some embodiments of the present application.

[0023] Figure 2 Schematic diagram of the internal structure of the electrode sheet of some embodiments of the present application.

[0024] Figure 3 Schematic diagram of the internal structure of electrode sheets according to other embodiments of the present application.

[0025] Figure 4 Schematic diagrams of the appearance of electrode sheets according to other embodiments of the present application.

[0026] The reference numerals in the specific implementation manner are as follows:

[0027] 10. Electrode sheet; 11. Current collector; 11a. Covering portion; 11b. Ear portion; 12. Electrode material portion; F. Thickness direction. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0029] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are 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 device or element referred to 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.

[0030] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0031] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature “above”, “above” and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature “below”, “below” and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0034] The present application embodiment provides an electrode sheet to solve the problem that electrode powder is easy to fall off from the current collector when preparing the electrode sheet by dry method. The electrode sheet adopts a current collector with a three-dimensional grid structure to carry the electrode material part, and the electrode material in the electrode material part can be embedded in the three-dimensional grid of the current collector, so that the electrode material part is tightly combined with the current collector and is not easy to fall off.

[0035] The electrode assembly proposed in the embodiment of the present application includes a diaphragm, a positive electrode sheet and a negative electrode sheet. The electrode sheet in the embodiment of the present application can be used as the positive electrode sheet or the negative electrode sheet of the electrode assembly. The positive electrode sheet and the negative electrode sheet are separated by a diaphragm, and the diaphragm can allow ions to pass through. The diaphragm can be made of, but not limited to, polyolefin, polypropylene or polyethylene. The electrode assembly can be wound, laminated, etc.

[0036] The electrode assembly is housed in a shell to form a battery cell provided in an embodiment of the present application. In addition to the shell and the electrode assembly housed in the shell, the battery cell may also include an electrolyte injected into the shell, an insulating film wrapped around the electrode assembly, etc. The battery cell may be a secondary battery or a primary battery, and the battery cell may be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell may be cylindrical, flat, rectangular, or in other shapes.

[0037] A battery can be prepared using the battery cells in the embodiments of the present application. In some embodiments, the battery includes a housing and at least one battery cell, each of which is contained in the housing. Typically, the housing contains multiple battery cells, which can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are connected in series and in parallel. The battery may also include other structures. For example, the battery may also include a busbar component for realizing electrical connection between multiple battery cells.

[0038] The battery provided in the embodiment of the present application can be applied to an electrical device to provide electrical energy for the electrical device. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, etc. Taking the electrical device as a vehicle as an example, the battery can be set at the rear, front or bottom of the vehicle, and the battery can provide electrical energy for the drive of the vehicle, and can also provide electrical energy for the control system of the vehicle.

[0039] The electrode sheet provided in the embodiments of the present application is described in detail below.

[0040] According to some embodiments of this application, please refer to Figure 1 , Figure 2 and Figure 3 The electrode sheet 10 provided in the embodiment of the present application includes a current collector 11 and an electrode material portion 12. The current collector 11 includes a covering portion 11a having a three-dimensional grid structure. The electrode material portion 12 is covered on the covering portion 11a, and a portion of the electrode material portion 12 is embedded in the three-dimensional grid of the covering portion 11a.

[0041] The current collector 11 has a conductive function and is used to collect current. Specifically, the current collector 11 can be made of metal materials such as copper, aluminum, nickel, etc., or can be a composite of a polymer and a metal material. When the electrode sheet 10 is used as a positive electrode sheet, the current collector 11 can be made of copper or nickel. When the electrode sheet 10 is used as a negative electrode sheet, the current collector 11 can be made of aluminum.

[0042] The electrode material part 12 is a layer structure formed by electrode materials. The electrode material generally includes an active substance, a conductive agent and an adhesive. The active substance can deintercalate lithium ions in the electrochemical reaction of the battery. When the electrode sheet 10 is a positive electrode sheet, its positive electrode active material can be but not limited to lithium borate, lithium titanate, lithium manganate, lithium cobaltate, lithium nickelate, etc. When the electrode sheet 10 is a negative electrode sheet, its negative electrode active material can be but not limited to artificial graphite, natural graphite, mesophase carbon microspheres, lithium titanate, silicon-based materials, tin-based materials, etc. The conductive agent can enhance the conductivity of the electrode sheet 10, so that the electrode sheet 10 has good charge and discharge performance. The conductive agent can be but not limited to conductive graphite, carbon nanotubes, graphene, carbon fiber, etc. The adhesive is mainly used to bond the components in the electrode material so that the electrode material can be formed into a film on the current collector 11. Common adhesives include polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), etc.

[0043] The current collector 11 includes a covering portion 11a, which is used to cover the electrode material to form an electrode material portion 12. It can be understood that the electrode material portion 12 is covered on the surface of the covering portion 11a. The electrode material portion 12 is usually covered on one end surface or both end surfaces of the covering portion 11a in its thickness direction F. In each figure, F represents the thickness direction F of the covering portion 11a (i.e., the thickness direction F of the current collector 11).

[0044] The covering portion 11a is in a three-dimensional grid structure. Specifically, the covering portion 11a can be a three-dimensional grid structure formed by weaving metal wires, or it can be a three-dimensional grid structure prepared by mechanical processing methods such as 3D printing. Understandably, a three-dimensional grid structure generally refers to a continuous, regular or irregular three-dimensional grid-like structure formed in a three-dimensional space by a plurality of nodes and a plurality of edges connecting these nodes. In an embodiment of the present application, a closed hole-like structure formed by a plurality of nodes and edges connecting these nodes in a three-dimensional grid structure is referred to as a single grid in a three-dimensional grid structure. A single grid can be a circular, polygonal, elliptical or other special-shaped structure.

[0045] In the embodiment of the present application, the electrode material part 12 is covered on the surface of the covering part 11a, and part of it is embedded in the grid of the covering part 11a, that is, part of the electrode material part 12 is embedded in the internal grid of the covering part 11a, and the contact between the electrode material part 12 and the current collector 11 can be increased through the three-dimensional grid, and the current transmission in multiple directions of the electrode sheet 10 can be strengthened. In addition, the connection strength between the electrode material part 12 and the current collector 11 is strong, and it is not easy for the electrode material part 12 and the current collector 11 to fall off, which helps to improve the reliability of the battery.

[0046] In some embodiments, the electrode material part 12 is rolled and compounded on the covering part 11a. In practical applications, the dry powder electrode material or the mud / slurry obtained by mixing the electrode material with a certain solvent can be laid on the covering part 11a by rolling. Under the action of pressure, the electrode material particles in the electrode material part 12 can be embedded in the three-dimensional grid of the covering part 11a. In this way, the forming of the electrode sheet 10 is facilitated.

[0047] If the electrode material portion 12 is formed from a raw material in a mud-like or slurry state, it is usually subjected to post-treatment such as drying after rolling.

[0048] Of course, in other embodiments, the electrode material portion 12 may be disposed on the covering portion 11a in other ways, and the electrode material portion 12 may be embedded in the three-dimensional grid structure. For example, the current collector 11 is immersed in a raw material in a slurry state, and then the electrode sheet 10 with a smooth surface of the electrode material portion 12 is obtained by post-processing such as scraping. For another example, the electrode material is sprayed on the covering portion 11a by spraying.

[0049] In some embodiments, the maximum particle size D of the active material contained in the electrode material part 12 is max The average minimum inner diameter R of the three-dimensional grid of the covering portion 11a min , satisfying: R min ≥D max .

[0050] It can be understood that, as described above, the three-dimensional grid of the covering portion 11a includes a plurality of grids, and the minimum inner diameter of each grid refers to the minimum vertical distance between the inner walls of the grid. If the grid is a circular hole, its minimum inner diameter is the diameter of the circular hole. If the grid is a rectangular hole, its minimum inner diameter is the shortest distance between the two long sides. The smaller the minimum inner diameter, the smaller the particle size that can be embedded in the grid.

[0051] The average minimum inner radius R of the three-dimensional grid min It is the average value of the minimum inner diameters of multiple grids in the three-dimensional grid. The multiple grids may include all grids in the three-dimensional grid, or the multiple grids may be a three-dimensional grid structure divided into multiple regions, where the grids in several relatively dispersed regions are taken as the sampling range, and the average value of the minimum inner diameters of the grids in the sampling range is calculated. For a three-dimensional grid structure with a relatively regular and consistent grid structure, the average minimum inner diameter of the grids in some regions may be measured and calculated.

[0052] As described above, the electrode material portion 12 contains an active material, and the maximum particle size D of the active material is max It refers to the maximum particle size of the active substance.

[0053] When the average minimum inner diameter R of the three-dimensional grid of the covering portion 11a is min Greater than or equal to D max Particles of any size in the active material in the electrode material part 12 can basically be embedded in the three-dimensional grid, so that the electrode material part 12 and the current collector 11 are more tightly combined and not easy to fall off.

[0054] It is understandable that when designing the size of the conductive agent in the electrode material, it should also be ensured that the conductive agent can be smoothly embedded in the three-dimensional grid of the covering portion 11 a.

[0055] In some embodiments, the median particle size D of the active material contained in the electrode material portion 12 is 50 , satisfying: R min ≥3D 50 . Median particle size D 50 It refers to the particle size corresponding to the percentage of particle size distribution of active particles in the active substance reaching 50%, usually for particles with a median particle size D 50 The active particles nearby account for a larger weight of the active material. At this time, for particles of conventional particle size in the active material, a grid can accommodate multiple particles. This helps to increase the content of active material in the electrode sheet 10, thereby increasing the capacity of the battery.

[0056] In some embodiments, R min Satisfy: 20um≥R min ≥35nm. Specifically, R min The values ​​can be 35nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1um, 5um, 10um, 15um, 20um and any value between adjacent values. min Meeting the above conditions can adapt to the preparation of most electrode sheets 10 .

[0057] In some embodiments, reference Figure 1 The coating thickness h of the electrode material portion 12 on the surface of the coating portion 11 a satisfies: 0<h≤300um.

[0058] It can be understood that the electrode material part 12 is partially embedded in the covering part 11a and partially covered on the surface of the covering part 11a. The covering thickness h of the electrode material part 12 refers to the thickness of the electrode material part 12 part covered on the surface of the covering part 11a, that is, the vertical distance between the outer surface of the electrode material part 12 and the surface covered by it in the covering part 11a. Usually, the protruding thickness h of the electrode material part 12 is equal everywhere. For example, the covering thickness h of the electrode material part 12 can be 10um, 20um, 50um, 80um, 100um, 130um, 150um, 180um, 200um, 220um, 260um, 300um and any value between adjacent values.

[0059] When the protruding thickness h of the electrode material portion 12 satisfies the above range, a battery manufactured using the electrode sheet 10 has a good electric capacity.

[0060] In some embodiments, reference Figure 3 The electrode material portion 12 is covered on at least one end of the covering portion 11a in the thickness direction F, and the depth of all the electrode material portions 12 embedded in the covering portion 11a is equal to the thickness of the covering portion 11a.

[0061] That is to say, along the thickness direction F of the covering portion 11a, the electrode material of the electrode material portion 12 is embedded from one end of the covering portion 11a to the other end of the covering portion 11a. When the electrode material portion 12 is arranged only at one end of the covering portion 11a, the electrode material portion 12 itself is embedded from one end of the covering portion 11a to the other end of the covering portion 11a. When the electrode material portion 12 is arranged at both ends of the covering portion 11a, the electrode material portions 12 at both ends can be, but are not limited to, embedded from the ends thereof to the 1 / 2 thickness position of the covering portion 11a. It can be understood that the embedding depth of the electrode material portions 12 at both ends can be equal, and the embedding positions can intersect in the thickness direction F.

[0062] In this way, the internal space of the covering portion 11a can be used as an expansion space for filling active materials, which greatly increases the content of active materials and greatly improves the capacity of the electrode sheet 10. Moreover, when the electrode material portion 12 is arranged on both the front and back sides of the covering portion 11a, the electrode material portions 12 at both ends can jointly cover the active materials inside the covering portion 11a to carry out lithium ion deintercalation, which can make the lithium ion deintercalation on both sides of the electrode sheet 10 more uniform, reduce the undesirable phenomenon of "yin and yang sides" on the electrode sheet 10, and at the same time reduce the uniformity requirements for the surface density of the electrode materials on the front and back sides of the electrode sheet 10.

[0063] In some embodiments, reference Figure 4 The current collector 11 further includes a pole ear portion 11 b . In the width direction of the current collector 11 , the pole ear portion 11 b is disposed adjacent to the covering portion 11 a , and the thickness of the pole ear portion 11 b is less than the thickness of the covering portion 11 a .

[0064] The pole ear portion 11b is used to connect (such as welding) an external bus structure, and the electrode sheet 10 is connected to an external circuit. The pole ear portion 11b can be welded to the covering portion 11a by welding or the like, or the covering portion 11a can be integrally formed. For example, the pole ear portion 11b is obtained by compacting both ends of a current collector 11 having a three-dimensional grid structure in the width direction.

[0065] The thickness of the pole ear portion 11 b is smaller than the thickness of the covering portion 11 a , so that the pole ear portion 11 b is easily connected to the external bus structure.

[0066] In some embodiments, the electrode material portion 12 is obtained by coating a raw material having an electrode material content of not less than 85% by mass on the coating portion 11 a .

[0067] As mentioned above, the electrode material of the electrode material part 12 mainly includes active materials, conductive agents, adhesives, etc. The raw materials can be formed on the covering part 11a by dry or wet preparation.

[0068] When dry preparation is adopted, the raw material is completely composed of electrode materials, that is, the mass content of the electrode powder is 100%, and the electrode powder can be partially embedded in the covering portion 11a by means of calendering (such as rolling, flat pressing).

[0069] For wet preparation, that is, adding a certain solvent to the electrode material, when the mass content of the electrode material in the raw material is 85% or above, a muddy raw material can be obtained by mixing the electrode material and the solvent. When the raw material is covered on the covering portion 11a, the electrode material in the raw material is easily embedded in the three-dimensional grid, and the material distribution in the electrode material on the covering portion 11a is more uniform, and the mass component of the electrode material is larger, which helps to ensure the compactness of the electrode material on the electrode sheet 10 and the capacitance of the electrode sheet 10.

[0070] It should be pointed out that the content of the electrode material is not less than 85% of the raw material mass or even reaches 100% of the raw material mass, which is a relatively conventional configuration ratio for those skilled in the art in wet and dry preparation. The content range value itself is not the main improvement point of the present application. The present application only applies the raw materials whose mass content of the electrode material is within the content range to the electrode sheet 10 of the present application. It has been verified that when the mass content of the electrode material is not less than 85%, the coating effect of the electrode material part 12 is small, the active material can be well embedded in the three-dimensional grid, and the capacitance of the electrode sheet 10 is good.

[0071] In addition, the present application also provides an electrode assembly, including a separator, a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and / or the negative electrode sheet is the electrode sheet 10 in any of the above embodiments, and a separator is provided between the positive electrode sheet and the negative electrode sheet. The electrode assembly can be wound or laminated, and its structure and material selection can be conventionally set.

[0072] In addition, the embodiment of the present application further provides a battery cell, comprising a housing and the click assembly of the above embodiment, wherein the electrode assembly is contained in the housing. Generally, the housing comprises a bottom housing and an end cover, wherein the bottom housing forms a cavity for containing the electrode assembly, and the end cover covers an open end of the cavity. A pole, an explosion-proof structure, etc. may be provided on the end cover. With regard to the specific structure of the battery cell, reference may be made to conventional settings.

[0073] In addition, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell. In some embodiments, the battery may further include a box body, wherein a plurality of battery cells are accommodated in the box body.

[0074] In addition, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery, and the battery is used to provide electrical energy.

[0075] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An electrode sheet (10), characterized in that: The electrode sheet (10) comprises: A current collector (11) comprising a covering portion (11a) in a three-dimensional grid structure; and An electrode material portion (12) is covered on the covering portion (11a), and a portion of the electrode material portion (12) is embedded in the three-dimensional grid of the covering portion (11a); The maximum particle size D of the active material contained in the electrode material part (12) is max The average minimum inner diameter R of the three-dimensional grid of the covering portion (11a) min , satisfying: R min ≥D max .

2. The electrode sheet (10) according to claim 1, characterized in that: The electrode material portion (12) is rolled and composited on the covering portion (11a).

3. The electrode sheet (10) according to claim 1, characterized in that: The median particle size D of the active material contained in the electrode material part (12) is 50 , satisfying: R min ≥3D 50 and / or, The R min Satisfy: 20um≥R min ≥35nm.

4. The electrode sheet (10) according to claim 1, characterized in that: The coating thickness h of the electrode material portion (12) on the surface of the coating portion (11a) satisfies: 0<h≤300um; and / or, The electrode material portion (12) is covered on at least one end of the covering portion (11a) in the thickness direction (F), and the depth of the entire electrode material portion (12) embedded in the covering portion (11a) is equal to the thickness of the covering portion (11a).

5. The electrode sheet (10) according to claim 1, characterized in that: The current collector (11) further comprises a pole ear portion (11b), which is arranged adjacent to the covering portion (11a) in the width direction of the current collector (11), and the thickness of the pole ear portion (11b) is smaller than the thickness of the covering portion (11a).

6. The electrode sheet (10) according to claim 5, characterized in that: The pole ear portion (11b) is welded to the covering portion (11a), or the pole ear portion (11b) and the covering portion (11a) are integrally formed.

7. An electrode assembly, characterized in that: It comprises a separator, a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet and / or the negative electrode sheet is the electrode sheet (10) according to any one of claims 1 to 6, and the separator is arranged between the positive electrode sheet and the negative electrode sheet.

8. A battery cell, characterized in that: The invention comprises a shell and the electrode assembly as claimed in claim 7, wherein the electrode assembly is accommodated in the shell.

9. A battery, characterized in that: Comprising the battery cell as claimed in claim 8.

10. An electrical device, characterized in that: Comprising a battery as claimed in claim 9, the battery is used to provide electrical energy.

Images