Current collector, pole piece, battery and coating roller

Abstract

The utility model relates to the technical field of batteries, and discloses a current collector, a pole piece, a battery and a coating roller. The current collector includes: a metal foil; the conductive layer is arranged on at least one surface of the metal foil; the conductive layer is provided with a first coating area used for coating the insulating layer and a second coating area used for coating the active material layer, and the first coating area is located on at least one side of the second coating area in the width direction of the conductive layer; the surface density of the first coating area is smaller than that of the second coating area. According to the current collector provided by the utility model, the first coating area and the second coating area are arranged on the conducting layer, and the surface density of the first coating area is smaller than that of the second coating area, so that the cohesiveness of the insulating coating and the metal foil is enhanced, the production cost is low, the coating areas are convenient to identify, and the service life of the current collector is prolonged. The production efficiency of the battery is improved, the cost is reduced and the product quality is ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a current collector, electrode, battery, and coating roller. Background Technology

[0002] In the battery industry, carbon-coated foil is often used as a current collector for electrodes to improve the electron transport efficiency between the current collector and the active material layer, thereby enhancing the current collector's charge-discharge performance. Carbon-coated foil consists of foil material and a carbon coating layer applied to the foil material. During electrode manufacturing, active material is typically coated onto the carbon coating layer to form an active material layer, and a ceramic coating is then applied to the foil material on both sides of the active material layer. However, the ceramic coating is prone to peeling off from the foil material, affecting the quality and effectiveness of the coating.

[0003] To address the issue of ceramic coating peeling, some technical solutions involve applying a primer layer to both sides of the carbon coating layer, with the ceramic coating then applied over the primer. However, adding a primer layer presents significant design and operational challenges, resulting in high production costs.

[0004] In some technical solutions, the width of the carbon coating layer is increased to coat part of the ceramic coating onto the carbon coating layer. However, when coating the ceramic coating and the active material layer, the lack of effective differentiation makes it difficult to quickly and accurately identify the coating areas of the ceramic coating and the active material layer, resulting in coating position deviations and an increase in product defect rates.

[0005] Therefore, designing a current collector that is easy to manufacture and allows for easy identification of the coated area during the coating process is of great significance for improving battery production efficiency, reducing costs, and ensuring product quality. Utility Model Content

[0006] In view of this, the present invention provides a current collector, electrode, battery and coating roller with high bonding strength with ceramic coating, low production cost and easy identification of coating area.

[0007] In a first aspect, the present invention provides a current collector comprising: a metal foil; a conductive layer disposed on at least one surface of the metal foil; the conductive layer having a first coating area for coating an insulating layer and a second coating area for coating an active material layer, wherein the first coating area is located on at least one side of the second coating area along the width direction of the conductive layer; and the areal density of the first coating area is less than the areal density of the second coating area.

[0008] In this embodiment, the conductive layer is divided into functional zones, namely a first coating area and a second coating area. An insulating layer is coated on the first coating area, and an active material layer is coated on the second coating area. This enhances the adhesion between the insulating layer and the metal foil, reduces or even eliminates the risk of insulation layer shedding, and allows for one-step coating, simplifying the operation and reducing production costs. Furthermore, the areal density of the first coating area is lower than that of the second coating area, resulting in different gray levels and thus different colors. During electrode manufacturing, the first and second coating areas can be accurately and quickly identified, improving the coating quality and efficiency of the insulating and active material layers and ensuring the consistency of battery performance.

[0009] In one optional embodiment, the areal density of the first coating area is 10%-90% of the areal density of the second coating area. This ensures that the first coating area and the second coating area exhibit a significant color difference, while also ensuring that the areal density of the second coating area is within a reasonable range, thereby guaranteeing the electron transport efficiency between the conductive layer and the active material layer.

[0010] In one optional embodiment, a first coating area is provided on both sides of the second coating area along the width direction of the conductive layer, so as to reduce the coating precision requirements of the active material layer and ensure the coating quality of the active material layer.

[0011] In one optional embodiment, the areal density of the first coating area is 0.01-2.0 g / m²; and / or, the areal density of the second coating area is 0.05-10 g / m². Thus, the grayscale of the first and second coating areas can fall between that of the insulating layer and the active material layer, resulting in colors that are also between those of the insulating layer and the active material layer. During electrode manufacturing, the coating state can be accurately identified through color differences, avoiding problems such as incomplete coating or defective products flowing into subsequent processes, ensuring the consistency and reliability of product quality.

[0012] In one alternative embodiment, the conductive layer has at least one high-roughness region disposed on the second coating area. The high-roughness region can enhance the adhesion between the active material layer and the conductive layer, improve the peel force of the electrode, and thus ensure the stability and high efficiency of the battery performance.

[0013] In one optional embodiment, the width of the high-roughness region remains constant along the length of the conductive layer to facilitate one-time coating of the conductive layer and reduce production costs. Understandably, in this embodiment, the high-roughness region is located in the second coating area, therefore the width of the high-roughness region is less than or equal to the width of the second coating area. Furthermore, there may be one high-roughness region, or two, three, or more regions spaced apart along the width of the conductive layer.

[0014] In one optional embodiment, the conductive layer has at least one thinning region, the thickness of which gradually decreases or first gradually decreases and then gradually increases in the width direction of the conductive layer. The thickness of the thinning region exhibits a gradual changing trend, avoiding problems such as stress concentration and poor flatness, and ensuring the uniformity and stability of the current collector surface.

[0015] In one optional embodiment, the width of the thinning region remains constant along the length direction of the conductive layer, so as to facilitate one-time coating and forming of the conductive layer and reduce production costs. It is understood that in this embodiment, there may be one thinning region, or two, three, or more regions spaced apart along the width direction of the conductive layer; the specific number and width can be adjusted adaptively according to requirements. Secondly, this utility model also provides an electrode sheet, comprising: a current collector as described above; an insulating layer disposed in and covering the first coating region; and an active material layer disposed in and covering the second coating region.

[0016] In this embodiment, the conductive layer is divided into functional zones, namely a first coating area and a second coating area. An insulating layer is coated on the first coating area, and an active material layer is coated on the second coating area. This enhances the adhesion between the insulating layer and the metal foil, reduces or even eliminates the risk of insulation layer shedding, and allows for one-step coating, simplifying the operation and reducing production costs. Furthermore, the areal density of the first coating area is lower than that of the second coating area, resulting in different gray levels and thus different colors. During electrode manufacturing, the first and second coating areas can be accurately and quickly identified, improving the coating quality and efficiency of the insulating and active material layers and ensuring the consistency of battery performance.

[0017] Thirdly, the present invention also provides a battery, including a positive electrode and a negative electrode; the positive electrode and / or the negative electrode includes a current collector as described above; or, the positive electrode and / or the negative electrode is an electrode as described above.

[0018] Fourthly, this utility model also provides a coating roller for preparing the current collector as described above. The coating roller has a first coating area corresponding to the first coating area and a second coating area corresponding to the second coating area. Both the first coating area and the second coating area are provided with a mesh pattern, and multiple cavities are formed within the mesh pattern. The mesh count of the first coating area is greater than that of the second coating area. And / or, the cavity depth of the first coating area is less than that of the second coating area.

[0019] In this embodiment, by dividing the coating roller into a first coating area and a second coating area, and by differentiating the mesh count and / or cell depth of the two areas, the conductive layer can be coated and formed in one step. Furthermore, by using the same conductive layer slurry, different coating colors can be achieved in different coating areas, simplifying the operation steps and reducing production costs. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a current collector according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of another current collector structure according to an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of another type of current collector according to an embodiment of the present utility model;

[0024] Figure 4 This is a schematic diagram of another current collector according to an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Metal foil; 11. Blank area; 2. Conductive layer; 21. First coating area; 22. Second coating area; 23. High roughness area; 24. Thinning area; X, length direction; Y, width direction. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] The following is combined with Figures 1 to 4 The following describes embodiments of the present invention.

[0029] According to an embodiment of the present invention, in one aspect, a current collector is provided, comprising a metal foil 1 and a conductive layer 2 disposed on at least one surface of the metal foil 1. For example... Figure 1-4 As shown, the conductive layer 2 has intersecting length direction X and width direction Y. In some cases, the conductive layer 2 is rectangular, with the length direction X and width direction Y perpendicular to each other. The conductive layer 2 has a first coating area 21 for coating an insulating layer and a second coating area 22 for coating an active material layer. Along the width direction Y of the conductive layer 2, the first coating area 21 is located on at least one side of the second coating area 22, and the areal density of the first coating area 21 is less than the areal density of the second coating area 22.

[0030] In this embodiment, the conductive layer 2 is divided into functional zones, namely a first coating area 21 and a second coating area 22. An insulating layer is coated on the first coating area 21, and an active material layer is coated on the second coating area 22. This enhances the adhesion between the insulating layer and the metal foil 1, reduces or even eliminates the risk of insulation layer shedding, and allows for one-time coating, simplifying the operation and reducing production costs. Furthermore, the areal density of the first coating area 21 is lower than that of the second coating area 22, resulting in different gray levels and thus different colors. During electrode manufacturing, the first coating area 21 and the second coating area 22 can be accurately and quickly identified, improving the coating quality and efficiency of the insulating layer and the active material layer, and ensuring the consistency of battery performance.

[0031] Specifically, the metal foil 1 also has a blank area 11 without the conductive layer 2 coated on it, and the first coated area 21 is located between the blank area 11 and the second coated area 22.

[0032] Specifically, the metal foil 1 includes, but is not limited to, copper foil, aluminum foil, gold foil, silver foil, composite metal foil 1, or alloy foil. The conductive layer 2 includes, but is not limited to, a carbon coating layer, a metal layer, etc., preferably a carbon coating layer. The insulating layer includes, but is not limited to, a ceramic coating, a polymer coating, etc., preferably a ceramic coating. The active material layer can be a positive electrode active material layer or a negative electrode active material layer, preferably a positive electrode active material layer.

[0033] Understandably, in the conductive layer 2 of this utility model, the first coating area 21 and the second coating area 22 are obtained by coating the same conductive layer slurry in one step. The areal density of the first coating area 21 is less than that of the second coating area 22. Therefore, the thickness of the first coating area 21 is less than that of the second coating area 22.

[0034] In some embodiments, the areal density of the first coating area 21 is 10%-90% of the areal density of the second coating area 22. In this embodiment, by controlling the ratio of the areal densities of the first coating area 21 and the second coating area 22, it is possible to make the first coating area 21 and the second coating area 22 exhibit different gray levels, thereby making their appearance colors significantly different, while ensuring that the areal density of the second coating area 22 is within a reasonable range, thus ensuring the electron transport efficiency between the conductive layer 2 and the active material layer, and thus ensuring the overall performance of the battery.

[0035] In some embodiments, the areal density of the first coating area 21 is 0.01-2.0 g / m²; and / or, the areal density of the second coating area 22 is 0.05-10 g / m². Typically, the grayscale L value of the electrode material is low, often below 5, while the grayscale L value of the insulating coating is high, often above 95. This invention tested the grayscale of the first and second coating areas at various areal densities. The tests showed that when the areal density of the first coating area 21 is in the range of 0.01-2.0 g / m², its grayscale L value is often between 20 and 95; and when the areal density of the second coating area 22 is in the range of 0.05-10 g / m², its grayscale L value is often between 5 and 90. Thus, the grayscale of the first coating area 21 and the second coating area 22 can be between that of the insulating layer and the active material layer, resulting in an appearance color between the two layers. During electrode manufacturing, color differences can accurately identify the coating status. If problems such as missed coating occur, they can be quickly identified and reported, preventing defective products from flowing into subsequent processes, reducing the scrap rate, and ensuring the consistency and reliability of product quality.

[0036] Furthermore, in some embodiments, a first coating area 21 is provided on both sides of the second coating area 22 along the width direction Y of the conductive layer 2. In conventional technology, the edge of the active material layer easily overflows beyond the conductive layer 2, causing the edge of the active material layer to be coated onto the metal foil 1. On the one hand, the adhesion between the active material layer and the metal foil 1 is poor, and it is easy to lose material during the die-cutting process; on the other hand, the surface dynamism of the metal foil 1 is much lower than that of the conductive layer 2, and the active material layer on the metal foil 1 is prone to shrinkage, posing a risk of thick edges. Therefore, conventional current collectors have high requirements for the coating precision of the active material layer, and the coating quality is often difficult to guarantee. In this embodiment, by providing first coating areas 21 on both sides of the second coating area 22, even if the active material layer overflows beyond the second coating area 22, the active material layer can still fall onto the first coating area 21, avoiding problems such as material loss and thick edges. Therefore, the technical solution of this utility model can reduce the coating precision requirements of the active material layer, have a wider process window compatibility, and at the same time, ensure the coating quality of the active material layer and improve product yield.

[0037] In some embodiments, the width of the first coating area 21 and the width of the second coating area 22 remain constant along the length direction X of the conductive layer 2. It is understood that the widths of the first coating area 21 and the second coating area 22 refer to their dimensions along the width direction Y of the conductive layer 2. This facilitates the one-layer coating of the conductive layer 2 using gravure coating processes, thereby improving production efficiency and reducing production costs.

[0038] For example, the first coating area 21 and / or the second coating area 22 can be in the form of strips, rectangles or other regular or irregular geometric structures, as long as the areal density of the first coating area 21 is less than that of the second coating area 22, so as to achieve the purpose of accurately and quickly identifying the first coating area 21 and the second coating area 22, and improving the coating quality and efficiency of the insulating layer and the active material layer.

[0039] In some embodiments, the metal foil 1 has two surfaces opposite each other in the thickness direction, and a conductive layer 2 is disposed on both surfaces.

[0040] In some embodiments, on the same surface of the metal foil 1, at least two conductive layers 2 are spaced apart in the width direction Y, and a blank area 11 is formed between two adjacent conductive layers 2 on the metal foil 1 to further improve the production efficiency of the current collector and reduce production costs. For example, as shown... Figure 2 As shown, in the width direction Y of the conductive layer 2, two conductive layers 2 can be spaced apart on the same surface of the metal foil 1. Both conductive layers 2 include the aforementioned first coating area 21 and second coating area 22. For example, as... Figure 3 As shown, three conductive layers 2 can be spaced apart on the same surface of the metal foil 1 along the width direction Y of the conductive layer 2. Each of the three conductive layers 2 includes the first coating area 21 and the second coating area 22 mentioned above.

[0041] Furthermore, in some embodiments, the conductive layer 2 has at least one high-roughness region 23, which is disposed on the second coating region 22. The high-roughness region 23 can enhance the adhesion between the active material layer and the conductive layer 2, improve the peeling force of the electrode, and thus ensure the stability and high efficiency of the battery performance.

[0042] In some embodiments, the width of the high-roughness region 23 remains constant along the length direction X of the conductive layer 2, so as to facilitate the one-time coating and forming of the conductive layer 2 and reduce production costs. It is understood that the width of the high-roughness region 23 refers to its dimension in the width direction Y of the conductive layer 2.

[0043] Understandably, in this embodiment, the high roughness region 23 is disposed in the second coating region 22, therefore the width of the high roughness region 23 is less than or equal to the width of the second coating region 22. Furthermore, there may be one high roughness region 23, or two, three, or more regions spaced apart along the width direction of the conductive layer 2. In some embodiments, the conductive layer 2 has at least one thinning region 24, and the thickness of the thinning region 24 gradually decreases along the width direction Y of the conductive layer 2, or first gradually decreases and then gradually increases. The thickness of the thinning region 24 exhibits a gradual changing trend, avoiding problems such as stress concentration and poor flatness, and ensuring the uniformity and stability of the current collector surface.

[0044] In some embodiments, the width of the thinning region 24 remains unchanged along the length direction X of the conductive layer 2, so as to achieve one-time coating and molding of the conductive layer 2 and reduce production costs.

[0045] Preferably, the thinning region 24 is located between different functional regions to avoid excessive thickness differences between them. The thickness variation trend of the thinning region 24 specifically depends on the thicknesses of the two adjacent functional regions. If the two adjacent functional regions have the same thickness, the thickness of the thinning region 24 can first decrease and then increase. If the two adjacent functional regions have different thicknesses, the thickness of the thinning region 24 can gradually decrease towards the direction away from the thicker functional region.

[0046] For example, such as Figure 4 As shown, both the thinning region 24 and the high-roughness region 23 are disposed in the second coating region 22, wherein the thinning region 24 connects the high-roughness region 23 and the second coating region 22, and the thickness of the thinning region 24 gradually decreases in the direction away from the high-roughness region 23. Exemplarily, in some embodiments not shown, the thinning region 24 may also be disposed at the junction of the first coating region 21 and the second coating region 22, or at the junction of the first coating region 21 and the high-roughness region 23.

[0047] Understandably, in this embodiment, there may be one thinning region 24, or there may be two, three or more regions spaced apart in the width direction of the conductive layer 2. The specific number and width dimensions can be adjusted according to the requirements.

[0048] In this invention, the conductive layer 2 of the current collector can be formed in one step using gravure coating technology, which is easy to operate, highly efficient, and low in cost. Specifically, the preparation method of the current collector is as follows:

[0049] Step 1: Apply a conductive layer paste to any surface of the metal foil 1 using a coating roller; the coating roller has a first coating area corresponding to the first coating area 21 and a second coating area corresponding to the second coating area 22; both the first coating area and the second coating area are provided with a mesh pattern, and multiple cells are formed within the mesh pattern; the mesh count of the first coating area is greater than the mesh count of the second coating area; and / or, the cell depth of the first coating area is less than the cell depth of the second coating area.

[0050] Step 2: Dry the conductive layer slurry to form conductive layer 2.

[0051] This invention controls the areal density of the first coating area 21 and the second coating area 22 by dividing the coating roller into sections and adjusting the mesh count and cell depth of different coating areas, thereby affecting the coating transfer amount and achieving a one-time coating process for the first coating area 21 and the second coating area 22. The mesh count and cell depth of the coating roller can be adaptively adjusted in conjunction with the areal density selection to ensure that different functional areas of the conductive layer 2 achieve the corresponding areal densities.

[0052] Understandably, the coating area division of the coating roller depends on the functional area division of the conductive layer 2.

[0053] In some cases, the conductive layer 2 also includes the aforementioned high-roughness region 23. At the position on the coating roller corresponding to the high-roughness region 23, by reducing the mesh count, this region becomes more conducive to carrying and transferring large particles during coating. Accordingly, the high-roughness region 23 formed by coating has a significantly larger particle size of the filler material than other areas, thereby creating a high-roughness surface characteristic.

[0054] In some cases, the conductive layer 2 is also provided with the aforementioned thinning region 24. At the position of the coating roller corresponding to the thinning region 24, the depth of the mesh is adjusted so that the depth of the mesh decreases in the axial direction or gradually decreases and then increases, thereby achieving a gradual change in the thickness of the corresponding thinning region 24.

[0055] Furthermore, in this invention, the conductive layer slurry forming the conductive layer 2 includes at least a conductive agent, a binder, and a solvent. It is understood that the conductive layer 2 of this invention forms different functional areas through a single coating of a conductive slurry, namely, a first coating area 21, a second coating area 22, a high-roughness area 23, and a thinning area 24. Since the areal density of each functional area differs, their thicknesses also differ. If the thickness of a functional area is too small, it will affect the adhesion and corrosion resistance of the corresponding area to a certain extent. Therefore, the overall adhesion and corrosion resistance of the conductive layer 2 can be improved by adjusting the material of the conductive layer slurry.

[0056] To improve the adhesion of conductive layer 2, an appropriate amount of adhesion promoter, such as silane coupling agent or titanate coupling agent, can be added to the conductive layer slurry. The adhesion promoter can form chemical bonds between conductive layer 2 and the insulating coating and active material layer, thereby enhancing the bonding force.

[0057] To improve the corrosion resistance of conductive layer 2, appropriate amounts of polymeric additives or fillers can be added to the conductive layer slurry to increase its density and thus enhance its corrosion resistance. The polymeric additives can be resins with large molecular weights, regular molecular chain structures, and good cross-linking properties. These resins can form a tight three-dimensional network structure during curing, thereby improving the density of conductive layer 2. The fillers can be substances with fine particle size, regular shape, and uniform distribution, preferably one or more of carbon black, carbon nanotubes, or micron-sized graphite powder, graphene, etc. Using these substances as fillers can improve the conductivity of conductive layer 2 while ensuring coverage and density at low areal density.

[0058] According to an embodiment of the present invention, another aspect provides an electrode sheet, comprising a current collector, an insulating layer, and an active material layer as described in the above embodiments. The insulating layer is disposed in and covers the first coating region 21. The active material layer is disposed in and covers the second coating region 22.

[0059] Understandably, the electrode of this invention can be either a positive electrode or a negative electrode.

[0060] In this embodiment, the conductive layer 2 is divided into functional zones, namely a first coating area 21 and a second coating area 22. An insulating layer is coated on the first coating area 21, and an active material layer is coated on the second coating area 22. This enhances the adhesion between the insulating layer and the metal foil 1, reduces or even eliminates the risk of insulation layer shedding, and allows for one-time coating, simplifying the operation and reducing production costs. Furthermore, the areal density of the first coating area 21 is lower than that of the second coating area 22, resulting in different gray levels and thus different colors. During electrode manufacturing, the first coating area 21 and the second coating area 22 can be accurately and quickly identified, improving the coating quality and efficiency of the insulating layer and the active material layer, and ensuring the consistency of battery performance.

[0061] In some embodiments, the width of the insulating layer may be equal to the width of the first coating area 21, and the width of the active material layer may be equal to the width of the second coating area 22.

[0062] According to an embodiment of the present invention, in another aspect, a battery is also provided, including a positive electrode, a negative electrode, a separator, an electrolyte, and a casing. The positive electrode and / or negative electrode may include the current collector described in the above embodiments, and may be the electrode as described in the above embodiments. The positive electrode, separator, and negative electrode together form an electrode assembly, and the electrode assembly and electrolyte are sealed within the casing.

[0063] Since the battery of this utility model includes the above-mentioned current collector or electrode, it has the same technical effects as the current collector and electrode of this utility model, and will not be described again here.

[0064] According to an embodiment of the present invention, in another aspect, a coating roller is also provided for preparing a current collector as described in the above embodiments. The coating roller has a first coating area corresponding to a first coating area 21 and a second coating area corresponding to a second coating area 22. Both the first coating area and the second coating area are provided with a mesh pattern, and a plurality of cells are formed within the mesh pattern. The mesh count of the first coating area is greater than that of the second coating area; and / or, the cell depth of the first coating area is less than that of the second coating area.

[0065] In this embodiment, by dividing the coating roller into a first coating area and a second coating area, and by differentiating the mesh count and / or cell depth of the two areas, the conductive layer 2 can be coated and formed in one step. Furthermore, by using the same conductive layer slurry, different coating colors can be achieved in different coating areas, which simplifies the operation steps and reduces production costs.

[0066] In some embodiments, the mesh count of the second coating region is 10%-90% of the mesh count of the first coating region. Thus, the mesh count of the first coating region is larger than that of the second coating region, resulting in a smaller cell area, a smaller transfer amount, and a smaller surface density of the coating obtained, so that the surface density of the first coating region 21 is less than that of the second coating region 22.

[0067] In some embodiments, the cell depth of the first coating region is 10%-90% of the cell depth of the second coating region. Thus, the cell depth of the first coating region is smaller than that of the second coating region, which can accommodate less coating material, resulting in a smaller transfer amount and a smaller areal density of the coating obtained, so that the areal density of the first coating region 21 is less than that of the second coating region 22.

[0068] In some embodiments, the coating roller may further have a third coating region corresponding to the high roughness region 23, and / or a fourth coating region corresponding to the thinning region 24. The width of each coating region is 0.2 mm to 1000 mm along the axial direction of the coating roller. It is understood that the coating roller includes, but is not limited to, having the aforementioned coating regions, and the distribution of the coating regions on the coating roller specifically depends on the functional partitioning of the conductive layer 2.

[0069] In some embodiments, the mesh count of the coating roller can be 10-500 mesh, and the cell depth can be 5-100 μm. The specific mesh count and cell depth of each coating area can be adjusted adaptively according to the areal density of the corresponding coating area.

[0070] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A current collector characterized by comprising: The application relates to a current collector, a battery electrode, a battery and a coating roller. The current collector comprises: a metal foil (1); a conductive layer (2) provided on at least one surface of the metal foil (1); the conductive layer (2) has a first coating area (21) for coating an insulating layer and a second coating area (22) for coating an active material layer, the first coating area (21) is located on at least one side of the second coating area (22) along the width direction (Y) of the conductive layer (2); 2. The current collector of claim 1, wherein the area density of the first coating area (21) is less than that of the second coating area (22).

3. The current collector of claim 1, wherein The area density of the first coating area (21) is 10%-90% of that of the second coating area (22).

4. The current collector of claim 1, wherein The areal density of the first coating zone (21) is 0.01-2.0 g / m 2 ; and / or, the areal density of the second coating zone (22) is 0.05-10 g / m 2 .

5. The current collector according to any one of claims 1 to 4, wherein The second coating area (22) is provided with the first coating area (21) on both sides along the width direction (Y) of the conductive layer (2).

6. The current collector of claim 5, wherein The conductive layer (2) has at least one high-roughness area (23) provided on the second coating area (22).

7. The current collector of any one of claims 1-4, wherein The width of the high-roughness area (23) remains unchanged along the length direction (X) of the conductive layer (2).

8. The current collector of claim 7, wherein The conductive layer (2) has at least one thinning area (24), the thickness of the thinning area (24) gradually decreases or first gradually decreases and then gradually increases along the width direction (Y) of the conductive layer (2).

9. A pole piece characterized by, The width of the thinning area (24) remains unchanged along the length direction (X) of the conductive layer (2). The application relates to a current collector, a battery electrode, a battery and a coating roller. The current collector comprises: a current collector according to any one of claims 1-8; 10. A battery, characterized by an insulating layer provided on the first coating area (21) and covering the first coating area (21); an active material layer provided on the second coating area (22) and covering the second coating area (22).

11. A coating roll for producing a current collector according to any one of claims 1 to 8, characterized in that The application relates to a battery electrode, a battery and a coating roller. The battery electrode comprises: a positive electrode sheet and a negative electrode sheet; the positive electrode sheet and / or the negative electrode sheet comprises the current collector according to any one of claims 1-8; or the positive electrode sheet and / or the negative electrode sheet is the electrode sheet according to claim 9. The coating roller has a first coating area corresponding to the first coating area (21) and a second coating area corresponding to the second coating area (22); the first coating area and the second coating area are provided with a mesh pattern, and a plurality of mesh holes are formed in the mesh pattern; wherein the mesh number of the first coating area is greater than that of the second coating area; and / or the mesh hole depth of the first coating area is less than that of the second coating area.

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