Pole piece, battery and electric device

Abstract

The utility model discloses a pole piece, a battery and an electric device, the pole piece comprises a current collector, at least one surface of the current collector is provided with a coated area and an uncoated area, and the coated area is coated with a first coating, an insulating layer and a second coating; the insulating layer is connected with the uncoated area, and a gap is formed between the insulating layer and the first coating in the first direction of the pole piece; the second coating covers the surface and the gap of the first coating along the thickness direction of the pole piece; wherein the edge, close to the insulating layer, of the second coating is connected with the edge, close to the first coating, of the insulating layer; or, the edge, close to the insulating layer, of the second coating covers part of the insulating layer, so that the second coating and the insulating layer are partially overlapped in the thickness direction. Therefore, the second coating of the pole piece covers the surface of the first coating and in the gap, the gap can prevent fusion of the first coating and the insulating layer, the boundary of the second coating is clear due to the position relation of the second coating and the insulating layer, the problem of poor appearance of the pole piece is solved, and the quality of the pole piece can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to an electrode plate, a battery provided with the electrode plate, and an electrical device provided with the battery. Background Art

[0002] In recent years, batteries have combined multiple advantages such as efficient energy storage, environmental protection, long life, high adaptability, affordability, and continuous technological progress, meeting the needs of modern society for portable, clean, and efficient energy. Therefore, they are widely used in many fields such as energy storage, power tools, electric bicycles, electric motorcycles, electric vehicles, aerospace, etc. Therefore, higher requirements are also put forward for the battery structure and performance. As an important part of the battery, the electrode plate has an important impact on the battery performance. How to optimize the electrode plate structure to avoid the situation where the CCD cannot normally grasp the edge and make the battery have better overall performance is an urgent problem to be solved in this field. Summary of the Utility Model

[0003] In view of this, the purpose of the utility model is to provide an electrode plate, a battery, and an electrical device, which can improve the overall performance of the battery.

[0004] To achieve the above purpose, the utility model provides the following technical solutions:

[0005] An electrode plate, comprising:

[0006] A current collector, at least one surface of the current collector is provided with a coated area and an uncoated area, the coated area is coated with a first coating, an insulating layer, and a second coating; the insulating layer is connected to the uncoated area, and there is a gap between the insulating layer and the first coating along the first direction of the electrode plate; along the thickness direction of the electrode plate, the second coating covers the surface of the first coating and the gap.

[0007] Wherein, the edge of the second coating close to the insulating layer is connected to the edge of the insulating layer close to the first coating;

[0008] Or, the edge of the second coating close to the insulating layer covers part of the insulating layer, so that the second coating and the insulating layer partially overlap along the thickness direction.

[0009] Optionally, in the above electrode plate, when the edge of the second coating close to the insulating layer covers part of the insulating layer, along the first direction, the overlapping dimension of the second coating and the insulating layer is 0.5 mm - 1.5 mm.

[0010] Optionally, in the above electrode plate, along the thickness direction, the thickness of the second coating is greater than the thickness of the insulating layer.

[0011] Optionally, in the above-mentioned electrode, along the thickness direction, the thickness of the first coating is less than the thickness of the insulating layer.

[0012] Optionally, in the above-mentioned electrode, along the first direction, the size of the gap between the insulating layer and the first coating is 1.5 mm - 2.5 mm.

[0013] Optionally, in the above-mentioned electrode, the thickness of the first coating is 1 μm - 2 μm;

[0014] and / or, the thickness of the insulating layer is 20 μm - 60 μm.

[0015] Optionally, in the above-mentioned electrode, the thickness of the second coating is not less than 70 μm.

[0016] Optionally, in the above-mentioned electrode, the first coating is a conductive carbon layer;

[0017] and / or, the second coating is an active material layer.

[0018] A battery includes the above-mentioned electrode.

[0019] An electrical device includes the above-mentioned battery.

[0020] It can be seen from the above technical solutions that in the electrode of the present utility model, there is a gap between the insulating layer and the first coating, and the second coating covers the surface and the gap of the first coating. The setting of the gap can prevent the first coating and the insulating layer from fusing with each other to form a fusion zone and affect the coating effect of the second coating. After the first coating and the insulating layer are coated, they are dried, and then the second coating is coated. On the one hand, it can prevent the first coating and the second coating from dissolving each other and affecting the edge gripping. On the other hand, it can prevent the first coating and the insulating layer from dissolving and mixing with each other and reducing the quality of the first coating and the insulating layer. The edge of the second coating close to the insulating layer is connected to the edge of the insulating layer close to the first coating, that is, the second coating and the insulating layer do not overlap with each other along the thickness direction; or, the edge of the second coating close to the insulating layer covers a part of the insulating layer, so that the second coating and the insulating layer partially overlap along the thickness direction of the electrode, that is, the second coating covers a part of the insulating layer to form a covering area, and the second coating is located above the insulating layer along the thickness direction of the electrode in the covering area; it can make the boundary of the second coating clear and distinct, improve the problem of poor appearance of the electrode, and is beneficial to CCD recognition and edge gripping, thereby being able to improve the quality of the electrode and ensure that the battery has better integrity. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 Structural schematic diagram of the pole piece provided by the embodiment of the present invention;

[0023] Figure 2 Side view of the pole piece provided by the embodiment of the present invention;

[0024] Figure 3 For this Figure 2 Partial enlarged view in;

[0025] Figure 4 Manufacturing flowchart of the pole piece provided by the embodiment of the present invention.

[0026] Wherein:

[0027] 1 - current collector, 11 - coating area, 12 - non - coating area, 111 - void,

[0028] 2 - first coating, 3 - insulating layer, 4 - second coating. Detailed implementation manners

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is the orientation or positional relationship based on the drawings or the orientation or positional relationship when the product of the present invention is usually placed. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] Such as Figures 1 - 4As shown, the embodiment of the present utility model provides a pole piece, which can improve the overall performance of the battery.

[0032] First of all, the pole piece includes a current collector 1. At least one surface of the current collector 1 is provided with a coated area 11 and an uncoated area 12 (that is, one surface of the current collector 1 is provided with a coated area 11 and an uncoated area 12, or the two opposite surfaces of the current collector 1 are respectively provided with their own coated areas 11 and uncoated areas 12). The coated area 11 is coated with a first coating 2, an insulating layer 3, and a second coating 4; the insulating layer 3 is connected to the uncoated area 12, and there is a gap 111 between the insulating layer 3 and the first coating 2 along the first direction of the pole piece; along the thickness direction of the pole piece, the second coating 4 covers the surface of the first coating 2 and the inside of the gap 111; wherein, the edge of the second coating 4 close to the insulating layer 3 is connected to the edge of the insulating layer 3 close to the first coating 2; or, the edge of the second coating 4 close to the insulating layer 3 covers a part of the insulating layer 3, so that the second coating 4 and the insulating layer 3 partially overlap in the thickness direction. The second coating 4 and the insulating layer 3 of the pole piece are clearly demarcated, preventing the problem of the insulating layer 3 being mixed with the slurry layer or the insulating layer 3 covering the slurry layer resulting in poor appearance of the pole piece, and being able to avoid the situation where the CCD cannot normally grasp the edge. Furthermore, the quality of the pole piece can be improved, the drawback that the double-sided deviation correction cannot be normally started in subsequent operations can be solved, which helps to improve the ability level of the overhang (the length and width directions of the negative pole piece are more than those of the positive pole piece) process between the positive and negative pole pieces, and also provides more reference ideas and directions for manufacturing a high-quality pole piece structure. It should be noted that the first direction is perpendicular to the thickness direction of the pole piece, and the first direction is shown in Figure 1 the arrow direction in. In addition, Figures 1 - 4 It shows that a first coating 2, an insulating layer 3, and a second coating 4 are provided on one surface of the current collector 1.

[0033] It can be seen that there is a gap 111 between the insulating layer 3 and the first coating 2 in the pole piece provided by the embodiment of the present utility model. The second coating 4 covers the surface of the first coating 2 and the inside of the gap 111. The setting of the gap 111 can prevent the first coating 2 and the insulating layer 3 from fusing with each other to form a fusion zone, which affects the coating effect of the second coating 4. After the first coating 2 and the insulating layer 3 are coated, they are dried, and then the second coating 4 is coated. On the one hand, it can prevent the first coating 2 and the second coating 4 from dissolving with each other and affecting the edge gripping. On the other hand, it can prevent the first coating 2 and the insulating layer 3 from dissolving with each other and causing cross-material flow, which reduces the quality of the first coating 2 and the insulating layer 3. The edge of the second coating 4 close to the insulating layer 3 is connected to the edge of the insulating layer 3 close to the first coating 2, that is, the second coating 4 and the insulating layer 3 do not overlap each other in the thickness direction; or, the edge of the second coating 4 close to the insulating layer 3 covers a part of the insulating layer 3, so that the second coating 4 and the insulating layer 3 partially overlap in the thickness direction of the pole piece, that is, the second coating 4 covers a part of the insulating layer 3 to form a covering area, and in the covering area, the second coating 4 is located above the insulating layer 3 in the thickness direction of the pole piece; it can make the boundary of the second coating 4 clear and distinct, improve the problem of poor appearance of the pole piece, and is beneficial to CCD recognition of edge gripping, thereby improving the quality of the pole piece and ensuring better overall performance of the battery.

[0034] During specific implementation, when the edge of the second coating 4 close to the insulating layer 3 covers a part of the insulating layer 3, along the first direction, the overlapping dimension of the second coating 4 and the insulating layer 3 is 0.5 mm - 1.5 mm. An appropriate covering dimension can ensure the effective connection between the second coating 4 and the insulating layer 3, prevent them from peeling or breaking due to volume change during the charge and discharge process of the battery, and improve the cycle life of the battery.

[0035] During specific implementation, in the thickness direction, the thickness of the second coating 4 is greater than the thickness of the insulating layer 3. It should be noted that since the second coating 4 covers a part of the first coating 2, a part of the gap, and a part of the insulating layer 3, the thickness of the second coating 4 in the statement that the thickness of the second coating 4 is greater than the thickness of the insulating layer 3 specifically refers to the thickness of the second coating 4 covering the part of the first coating 2. The second coating 4 is the active part of the battery electrode and directly participates in the electrochemical reaction. A thicker thickness of the second coating 4 can accommodate more active substances, thereby improving the total energy storage capacity of the battery. The main function of the insulating layer 3 is to provide insulation or semi-insulation performance, prevent internal short circuit, and improve the safety of the battery. And in the thickness direction, the top surface of the second coating 4 is higher than the top surface of the insulating layer 3, which is beneficial to realizing the second coating 4 covering the insulating layer 3, and can ensure the flatness of the surface of the second coating 4, improve the appearance quality of the pole piece, and in addition, in the subsequent rolling process, it can effectively prevent the insulating layer from sticking to the roller.

[0036] In specific implementation, along the thickness direction, the thickness of the first coating 2 is less than that of the insulating layer 3. The first coating 2 is a conductive carbon layer, which is mainly used to improve the adhesion between the current collector 1 and the second coating 4. Its thickness only needs to meet the bonding effect, and too large thickness is not conducive to improving the total energy storage capacity of the battery.

[0037] In specific implementation, along the first direction, the size of the gap 111 between the insulating layer 3 and the first coating 2 is 1.5 mm - 2.5 mm. This can effectively prevent the mutual dissolution between the first coating 2 and the insulating layer 3. The preferred size of the gap is 2 mm, but it is not limited thereto. As long as the gap size can avoid the situation that the gap is too small to prevent the mutual dissolution between the first coating 2 and the insulating layer 3, and at the same time avoid the situation that the gap is too large to affect the connection effect between the second coating 4 and the current collector 1, the specific size of the gap can be specifically designed by those skilled in the art according to actual needs.

[0038] In specific implementation, the thickness of the first coating 2 is 1 μm - 2 μm; this can effectively improve the adhesion and make the second coating 4 better adhere to the current collector 1. The preferred thickness is 1.5 μm, but it is not limited thereto. The specific thickness of the first coating 2 can be specifically designed by those skilled in the art according to actual needs. And / or, the thickness of the insulating layer 3 is 20 μm - 60 μm. It should be noted that this thickness is the thickness of the insulating layer 3 provided on one side of the current collector 1. When insulating layers 3 are provided on both surfaces of the current collector 1, the thickness of the insulating layer 3 on each surface is 20 μm - 60 μm. It should be noted that the insulating layer 3 is composed of a binder and alumina. The insulating layer 3 can not only prevent the short circuit between the positive and negative electrode plates, but also serve as the subsequent die-cutting and slitting cutting position, and even can serve as the tab support position. The thickness of the insulating layer 3 can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, but it is not limited thereto. The specific thickness of the insulating layer 3 can be specifically designed by those skilled in the art according to actual needs.

[0039] In specific implementation, the thickness of the second coating 4 is not less than 70 μm. The second coating 4 is a non-Newtonian fluid with a thickness of more than 70 μm. The second coating 4 is ejected from the slit outlet of the coater die head and coated on the current collector 1 with the dried first coating 2 attached, and coated on the current collector 1 with the dried insulating layer 3 and the first coating 2 attached; the thickness of the insulating layer 3 is lower than that of the second coating 4, and the slurry of the second coating will slightly cover the insulating layer 3. The second coating 4 is the active part of the battery electrode and directly participates in the electrochemical reaction. A thicker thickness of the second coating 4 can accommodate more active substances, thereby improving the total energy storage capacity of the battery. The specific thickness of the second coating 4 can be specifically designed by those skilled in the art according to actual needs.

[0040] In specific implementation, the first coating 2 is a conductive carbon layer. The first coating 2 can not only make the connection effect between the current collector 1 and the second coating 4 better, but also conduct electricity. The first coating 2 includes conductive carbon and a binder, and the conductive carbon layer can be coated into a gravure material layer. The gravure material layer can protect the current collector 1 from being eroded by the electrolyte, but is not limited to this. The conductive carbon layer can also be coated into a planar layer; and / or, the second coating 4 is an active material layer, and the second coating 4 includes a conductive agent, a binder, an active material and an additive.

[0041] In specific implementation, for details, see Figure 4 , the preparation of the electrode includes:

[0042] First, spray the insulating layer 3 and the first coating 2 on the current collector 1 at the same time, and ensure a gap between them;

[0043] After the insulating layer 3 and the first coating 2 are sprayed, then dry them by baking;

[0044] After drying, spray the second coating 4;

[0045] After that, perform cutting to obtain the shape of the electrode required in the battery. The uncoated area 12 of the electrode is an empty foil area, and the tab can be cut out.

[0046] The embodiment of the present invention provides a battery including the above electrode.

[0047] It can be seen that there is a gap 111 between the insulating layer 3 and the first coating 2 of the electrode in the battery provided by the embodiment of the present invention. The second coating 4 covers the surface of the first coating 2 and the gap 111. The setting of the gap 111 can prevent the first coating 2 and the insulating layer 3 from fusing with each other to form a fusion zone, which affects the coating effect of the second coating 4. And after the first coating 2 and the insulating layer 3 are coated, they are dried by baking, and then the second coating 4 is coated. On the one hand, it can prevent the first coating 2 and the second coating 4 from dissolving each other and affecting the edge gripping. On the other hand, it can prevent the first coating 2 and the insulating layer 3 from dissolving and mixing materials, which reduces the quality of the first coating 2 and the insulating layer 3. The edge of the second coating 4 close to the insulating layer 3 is connected to the edge of the insulating layer 3 close to the first coating 2, that is, the second coating 4 and the insulating layer 3 do not overlap with each other in the thickness direction; or, the edge of the second coating 4 close to the insulating layer 3 covers a part of the insulating layer 3, so that the second coating 4 and the insulating layer 3 partially overlap in the thickness direction of the electrode, that is, the second coating 4 covers a part of the insulating layer 3 to form a covering area. In the covering area, the second coating 4 is located above the insulating layer 3 in the thickness direction of the electrode; this can make the boundary of the second coating 4 clear and distinct, improve the problem of poor appearance of the electrode, and is conducive to CCD recognition and edge gripping, thereby improving the quality of the electrode and ensuring better overall performance of the battery.

[0048] The embodiment of the present invention provides an electrical device including the above battery.

[0049] The electrical devices of the present utility model are not particularly limited, and may include, but are not limited to: laptop computers, pen-input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets, video recorders, LCD TVs, portable cleaners, portable CD players, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, motorcycles, motorized bicycles, bicycles, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, large household batteries, and lithium-ion capacitors, etc.

[0050] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0051] In this specification, the various embodiments are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0052] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present utility model. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present utility model. Therefore, the present utility model will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pole piece, characterized in that, Comprising: A current collector (1), at least one surface of the current collector (1) being provided with a coated area (11) and an uncoated area (12), the coated area (11) being coated with a first coating (2), an insulating layer (3), and a second coating (4); the insulating layer (3) being connected to the uncoated area (12), and there being a gap (111) between the insulating layer (3) and the first coating (2) along the first direction of the electrode; along the thickness direction of the electrode, the second coating (4) covers the surface of the first coating (2) and the inside of the gap (111); Wherein, the edge of the second coating (4) close to the insulating layer (3) is connected to the edge of the insulating layer (3) close to the first coating (2); Or, the edge of the second coating (4) close to the insulating layer (3) is provided to cover a part of the insulating layer (3), so that the second coating (4) and the insulating layer (3) partially overlap along the thickness direction.

2. The pole piece according to claim 1, characterized in that, When the edge of the second coating (4) close to the insulating layer (3) is provided to cover a part of the insulating layer (3), along the first direction, the overlapping dimension of the second coating (4) and the insulating layer (3) is 0.5 mm - 1.5 mm.

3. The pole piece according to any one of claims 1 to 2, characterized in that, Along the thickness direction, the thickness of the second coating (4) is greater than the thickness of the insulating layer (3).

4. The pole piece according to any one of claims 1 to 2, characterized in that, Along the thickness direction, the thickness of the first coating (2) is less than the thickness of the insulating layer (3).

5. The pole piece according to claim 1, wherein Along the first direction, the dimension of the gap (111) between the insulating layer (3) and the first coating (2) is 1.5 mm - 2.5 mm.

6. The pole piece according to claim 1, wherein, The thickness of the first coating (2) is 1 μm - 2 μm; And / or, the thickness of the insulating layer (3) is 20 μm - 60 μm.

7. The pole piece according to claim 1, characterized in that, The thickness of the second coating (4) is not less than 70 μm.

8. The pole piece according to claim 1, characterized in that, The first coating (2) is a conductive carbon layer; And / or, the second coating (4) is an active material layer.

9. A battery, characterized in that, Comprising an electrode as described in any one of claims 1 - 8.

10. An electrical device, characterized in that, Comprising a battery according to claim 9.

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