Pole piece and coating method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-08-11
AI Technical Summary
[0016]与现有技术相比，由于本申请实施例的极片包括基材、第一涂层和第二涂层，且第一涂层设置于基材的侧面，第二涂层设置于第一涂层的背离基材的侧面，并呈网格状布置，使得本申请的极片的表面积更大，提升极片的孔隙结构，大幅度提升锂离子电池性能，例如：倍率性能及安全性能，还可以改善锂离子电池的循环寿命；第一涂层和第二涂层的配合还能提高极片的柔韧性，能有效改善卷芯制备过程中的一致性；还可以创造一定的涂层内部空间，为锂离子电池充电时提供膨胀应力释放空间，可以有效改善锂离子电池的体积膨胀问题，降低锂离子电池形变风险；第一涂层和第二涂层的配合还可提高锂离子电池的保液能力，内部封闭空间能提供电解液存储空间，且在锂离子电池体积膨胀时，能防止电解液被挤走，极大地改善了电解液在充放电时的迁移运动。能大幅度提升锂离子电池的电化学性能。
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Figure CN122552460A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of batteries, and more particularly to an electrode. Background Technology
[0002] The coatings on existing electrodes are generally uniform and regular. The improvement effect on the electrochemical performance and safety of lithium-ion batteries under extreme conditions is generally limited. However, the demand for customized lithium-ion batteries is increasing. Their diversity and high requirements urgently necessitate improving the rate performance and extending the cycle life of batteries by changing the electrode structure while ensuring electrical and safety performance.
[0003] Therefore, there is an urgent need for an electrode that can improve battery performance and extend cycle life to overcome the above-mentioned defects. Summary of the Invention
[0004] The purpose of this application is to provide an electrode that can improve battery performance and extend cycle life.
[0005] To achieve the above objectives, embodiments of this application provide an electrode sheet, including a substrate, a first coating, and a second coating. The first coating is disposed on the side of the substrate, and the second coating is disposed on the side of the first coating opposite to the substrate, and arranged in a grid pattern.
[0006] In some embodiments, the thickness of the first coating is not less than the thickness of the second coating.
[0007] In some embodiments, the second coating includes a first linear coating area extending along a first direction and a second linear coating area extending along a second direction, wherein the first direction and the second direction are not parallel, and a plurality of the first linear coating areas are spaced apart along the second direction, and a plurality of the second linear coating areas are spaced apart along the first direction.
[0008] In some embodiments, the second coating includes a plurality of block coating areas, all of which can be divided into a plurality of first arrangement groups, each of which includes a plurality of block coating areas arranged at intervals along the first direction; all of which can also be divided into a plurality of second arrangement groups, each of which includes a plurality of block coating areas arranged at intervals along the second direction; the first direction and the second direction are not parallel.
[0009] In some embodiments, all the first arrangement groups are arranged at intervals along the second direction, and all the second arrangement groups are arranged at intervals along the first direction.
[0010] In some embodiments, the number of block coating regions in each of the first arrangement groups is the same; the number of block coating regions in each of the second arrangement groups is the same.
[0011] In some embodiments, the block coating areas in any two of the first arrangement groups are aligned one-to-one along the second direction; and / or, the block coating areas in any two of the second arrangement groups are aligned one-to-one along the first direction.
[0012] In some embodiments, the block coating areas in any two adjacent first arrangement groups are staggered along the second direction; and / or, the block coating areas in any two second arrangement groups are staggered along the first direction.
[0013] In some embodiments, the number of block coating regions in any two adjacent first arrangement groups is different, and / or the number of block coating regions in any two adjacent second arrangement groups is different.
[0014] In some embodiments, in any three adjacent first arrangement groups, the number of block coating areas in the first and last first arrangement groups along the second direction is the same, and the number is different from that in the middle first arrangement group.
[0015] This application also provides a coating method applicable to manufacturing electrode sheets as described above using a coating die. The coating die includes a plurality of first modules, second modules, and third modules. The second module is disposed between the plurality of first modules and the third module. Each first module and the second module form a first mold cavity, and the third module and the second module form a second mold cavity. The coating method includes: After the substrate is unwound, it is moved to the coating die head by the transfer roller. The second die cavity extrudes the first coating material to coat the substrate, thereby forming the first coating layer on the substrate. Each of the first cavities extrudes a second coating material to coat the substrate coated with the first coating, thereby forming the second coating on the first coating.
[0016] Compared with the prior art, the electrode of this application includes a substrate, a first coating, and a second coating. The first coating is disposed on the side of the substrate, and the second coating is disposed on the side of the first coating opposite to the substrate, arranged in a grid pattern. This results in a larger surface area for the electrode, improving its porosity and significantly enhancing the performance of the lithium-ion battery, such as rate performance and safety performance. It also improves the cycle life of the lithium-ion battery. The combination of the first and second coatings also improves the flexibility of the electrode, effectively improving the consistency during the core fabrication process. Furthermore, it creates internal space within the coatings, providing space for stress release during charging, effectively mitigating the volume expansion problem of lithium-ion batteries and reducing the risk of deformation. The combination of the first and second coatings also improves the electrolyte retention capacity of the lithium-ion battery. The enclosed internal space provides electrolyte storage space and prevents the electrolyte from being squeezed out during battery volume expansion, greatly improving electrolyte migration during charging and discharging. This significantly enhances the electrochemical performance of the lithium-ion battery. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a side view of the electrode sheet of the first embodiment of this application.
[0019] Figure 2 for Figure 1 The front view of the electrode shown.
[0020] Figure 3 This is a side view of the electrode sheet according to the second embodiment of this application.
[0021] Figure 4 for Figure 3 The front view of the electrode shown.
[0022] Figure 5 This is a side view of the electrode sheet according to the third embodiment of this application.
[0023] Figure 6 for Figure 5 The front view of the electrode shown.
[0024] Figure 7 This is a three-dimensional view of the coating die.
[0025] Figure 8 for Figure 7 The front view of the coating die head shown.
[0026] Figure 9 for Figure 7 The side view of the coating die shown.
[0027] Figure 10 for Figure 7 The rear view of the coating die head shown.
[0028] Figure 11 This is a flowchart of the electrode manufacturing method of this application. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0030] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0032] First, in the description of the embodiments of this application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0033] Secondly, the terms "first," "second," and "third" are used only to distinguish descriptions and have no order or distinction of importance. They should not be interpreted as indicating or implying relative importance. Features marked "first" or "second" may explicitly or implicitly include one or more of the same feature.
[0034] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted; the term "along a certain direction" does not imply that it must be absolutely parallel to that direction, but can be offset, that is, it can have a component in that direction.
[0035] Furthermore, it should be noted in the description of this application that, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, electromagnetic connections, or even communication connections; they can refer to direct connections or indirect connections through an intermediate medium, or even internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0036] Furthermore, in this application, "and / or," such as "feature 1 and / or feature 2," refers to three possibilities: feature 1 alone, feature 2 alone, or feature 1 plus feature 2.
[0037] Please see Figure 1-2 The electrode 100a of the first embodiment of this application includes a substrate 10, a first coating 20, and a second coating 30. The first coating 20 is disposed on the side of the substrate 10, and the second coating 30 is disposed on the side of the first coating 20 facing away from the substrate 10, and arranged in a grid pattern. More specifically, as follows: In some embodiments, when the electrode is a positive electrode, the first coating 20 may include one or more materials selected from lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide, and the second coating 30 may include one or more materials selected from lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, alumina, lithium iron phosphate, lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide, lithium lanthanum zirconium titanium oxide, lithium lanthanum titanium oxide, lithium aluminum germanium phosphate, titanium oxide, and zirconium oxide. The electrode structure design in this embodiment can significantly improve the safety performance of lithium-ion batteries.
[0038] In some embodiments, when the electrode is a negative electrode, the first coating 20 includes one or more materials selected from graphite, silicon-carbon negative electrode, silicon-oxygen negative electrode, and graphite and silicon negative electrode, and the second coating 30 includes one or more materials selected from graphite, silicon-carbon negative electrode, silicon-oxygen negative electrode, and silicon-graphite composite negative electrode. The coating structure design in this embodiment can significantly improve the rate performance and cycle stability of lithium-ion batteries, and is beneficial in reducing volume expansion during the charging and discharging process of lithium-ion batteries, thus reducing the risk of deformation.
[0039] In some embodiments, the thickness of the first coating 20 is not less than the thickness of the second coating 30.
[0040] like Figure 1-2 As shown, in the electrode 100a of the first embodiment of this application, the second coating 30 includes a first linear coating area 41 extending along a first direction and a second linear coating area 42 extending along a second direction. The first direction and the second direction are not parallel. Multiple first linear coating areas 41 are spaced apart along the second direction, and multiple second linear coating areas 42 are spaced apart along the first direction, forming a crisscrossing grid, which is beneficial to increase the surface area of the electrode and improve the pore structure and flexibility of the electrode.
[0041] Compared with the electrode 100a of the first embodiment of this application, the electrode 100b of the second embodiment of this application differs only in the specific structure of the second coating 20. The second coating 30 in the electrode 100b of the second embodiment of this application does not include the first linear coating area 41 and the second linear coating area 42. The second coating 30 in the electrode 100b of the second embodiment of this application is as follows: like Figure 3-4 As shown, the electrode 100b of the second embodiment of this application includes a second coating 30 comprising a plurality of block coating areas 50. All block coating areas 50 can be divided into a plurality of first arrangement groups 51, each of which includes a plurality of block coating areas 50 arranged at intervals along a first direction. All block coating areas 50 can also be divided into a plurality of second arrangement groups 52, each of which includes a plurality of block coating areas 50 arranged at intervals along a second direction. The first and second directions are not parallel, which is beneficial to increasing the surface area of the electrode and improving the pore structure and flexibility of the electrode.
[0042] like Figure 3-4 As shown, in the electrode 100b of the second embodiment of this application, all the first arrangement groups 51 are arranged at intervals along the second direction, and all the second arrangement groups 52 are arranged at intervals along the first direction, which is beneficial to further improve the flexibility of the electrode and effectively improve the consistency in the core preparation process.
[0043] like Figure 3-4As shown, in the electrode 100b of the second embodiment of this application, the number of block coating areas 50 in each first arrangement group 51 is the same; the number of block coating areas 50 in each second arrangement group 52 is the same, and the uniform layout is conducive to the balance of flexibility.
[0044] like Figure 3-4 As shown, in the electrode 100b of the second embodiment of this application, the block coating areas 50 in any two first arrangement groups 51 are aligned one by one along the second direction; and / or, the block coating areas 50 in any two second arrangement groups 52 are aligned one by one along the first direction, which is beneficial to further improve the flexibility of the electrode and effectively improve the consistency in the core preparation process.
[0045] Since the remaining structure of the electrode 100b in the second embodiment is the same as that of the electrode 100a in the first embodiment, it will not be described in detail here.
[0046] Compared with the electrode 100b of the second embodiment of this application, the electrode 100c of the third embodiment of this application differs only in the specific arrangement of the block coating areas 50 in the first arrangement group 51 and the second arrangement group 52, as follows: like Figure 5-6 As shown, the electrode 100c of the third embodiment of this application is arranged in a way that the block coating areas 50 in any two adjacent first arrangement groups 51 are staggered along the second direction, which is beneficial to increasing the surface area of the electrode 100.
[0047] like Figure 5-6 As shown, in the third embodiment of this application, the electrode 100c has block coating areas 50 in any two second arrangement groups 52 staggered along the first direction, which is beneficial to increasing the surface area of the electrode.
[0048] like Figure 5-6 As shown, in the electrode 100c of the third embodiment of this application, the number of block coating areas 50 in any two adjacent first arrangement groups 51 is different, which is beneficial to improving the pore structure and flexibility of the electrode.
[0049] like Figure 5-6 As shown, the number of blocky coating areas 50 in any two adjacent second arrangement groups 52 is different, which is beneficial to improving the pore structure and flexibility of the electrode.
[0050] like Figure 5-6 As shown, in the electrode 100c of the third embodiment of this application, in any three adjacent first arrangement groups 51, the number of block coating areas 50 in the first first arrangement group 51 and the last first arrangement group 51 along the second direction is the same, and the number is different from that of the middle first arrangement group 51, which is beneficial to improving the uniformity of electrode flexibility.
[0051] Since the remaining structure of the electrode 100c in the third embodiment is the same as that of the electrode 100b in the second embodiment, it will not be described in detail here.
[0052] Please see Figure 7-11 The coating die head 200 of this application embodiment includes a plurality of first modules 210, second modules 220, and third modules 230. The second module 220 is disposed between the plurality of first modules 210 and third modules 230. A second mold cavity 200b is formed between the third module 230 and the second module 220 for forming a first coating 20 on the substrate 10. Each first module 210 and the second module 220 form a first mold cavity 200a. Each first mold cavity 200a is an independent cavity for forming a grid-like arrangement of the second coating 30 on the first coating 20. More specifically, as follows: like Figure 7-11 As shown, each of the first mold cavity 200a and the second mold cavity 200b is provided with an independent mold cavity inlet 200c for independent feeding. Preferably, each mold cavity inlet 200c is provided with an intermittent valve 240 for independent, regular intermittent coating.
[0053] like Figure 7-11 As shown, both the first mold cavity 200a and the second mold cavity 220b are provided with buffer grooves 200d to adjust the pressure of the coating material entering the mold cavity, thereby achieving pressure buffering and playing a role in stabilizing and controlling the coating thickness and areal density.
[0054] Please see Figure 11 The coating method of this application embodiment is applicable to manufacturing electrode sheets 100a, 100b, and 100c using the coating die 200 described above, and includes: After the substrate 10 is unwound, it is moved to the coating die head 200 by the transfer roller. The second die cavity 200b extrudes the first coating material to coat the substrate 10, so as to form a first coating 20 on the substrate 10. Each first mold cavity 200a extrudes a second coating material to coat the substrate 10 coated with the first coating layer 20, thereby forming a second coating layer 30 on the first coating layer 20.
[0055] Specifically, during the manufacturing process, the coating of each mold cavity can be carried out independently and intermittently using an intermittent valve. Compared with the prior art, the electrode sheet of this application includes a substrate 10, a first coating 20, and a second coating 30. The first coating 20 is disposed on the side of the substrate 10, and the second coating 30 is disposed on the side of the first coating 20 away from the substrate 10 and arranged in a grid pattern. This results in a larger surface area and improved porosity of the electrode sheet, which can significantly improve the performance of lithium-ion batteries, such as rate performance and safety performance, and also improve the cycle life of lithium-ion batteries. The combination of the first coating 20 and the second coating 30 can also improve the flexibility of the electrode sheet, effectively improving the consistency in the core preparation process. It can also create a certain internal space within the coating, providing space for the expansion stress release during lithium-ion battery charging, which can effectively improve the volume expansion problem of lithium-ion batteries and reduce the risk of lithium-ion battery deformation. The combination of the first coating 20 and the second coating 30 can also improve the electrolyte retention capacity of lithium-ion batteries. The internal closed space can provide electrolyte storage space, and when the volume of lithium-ion batteries expands, it can prevent the electrolyte from being squeezed out, greatly improving the migration movement of electrolyte during charging and discharging. It can significantly improve the electrochemical performance of lithium-ion batteries.
[0056] The above-disclosed examples are merely preferred embodiments of this application, intended to facilitate understanding and implementation by those skilled in the art. However, they cannot be used to limit the scope of this application. Therefore, equivalent variations made within the scope of this application are still within the scope of this application.
Claims
1. A pole piece, characterized in that, It includes a substrate, a first coating and a second coating, wherein the first coating is disposed on the side of the substrate and the second coating is disposed on the side of the first coating opposite to the substrate and arranged in a grid pattern.
2. The pole piece of claim 1, wherein The thickness of the first coating is not less than the thickness of the second coating.
3. The pole piece of claim 1, wherein The second coating includes a first linear coating area extending along a first direction and a second linear coating area extending along a second direction. The first direction and the second direction are not parallel. Multiple first linear coating areas are spaced apart along the second direction, and multiple second linear coating areas are spaced apart along the first direction.
4. The pole piece of claim 1, wherein The second coating includes multiple block coating areas, all of which can be divided into multiple first arrangement groups, each of which includes multiple block coating areas arranged at intervals along the first direction; all of which can also be divided into multiple second arrangement groups, each of which includes multiple block coating areas arranged at intervals along the second direction; the first direction and the second direction are not parallel.
5. The pole piece of claim 4, wherein All the first arrangement groups are arranged at intervals along the second direction, and all the second arrangement groups are arranged at intervals along the first direction.
6. The pole piece of claim 5, wherein The number of block coating areas is the same in each of the first arrangement groups; the number of block coating areas is the same in each of the second arrangement groups.
7. The pole piece of claim 6, wherein The block coating areas in any two of the first arrangement groups are aligned one-to-one along the second direction; and / or, the block coating areas in any two of the second arrangement groups are aligned one-to-one along the first direction.
8. The pole piece of claim 4, wherein The block coating areas in any two adjacent first arrangement groups are staggered along the second direction; and / or, the block coating areas in any two second arrangement groups are staggered along the first direction.
9. The electrode sheet as described in claim 8, characterized in that, The number of block coating areas in any two adjacent first arrangement groups is different. In any three adjacent first arrangement groups, the number of block coating areas in the first and last first arrangement groups along the second direction is the same, but different from the number in the middle first arrangement group. And / or, The number of blocky coating areas in any two adjacent second arrangement groups is different. In any three adjacent second arrangement groups, the number of blocky coating areas in the first and last second arrangement groups along the first direction is the same, but different from the number in the middle second arrangement group.
10. A coating method suitable for manufacturing a pole piece according to any one of claims 1-9 by means of a coating die, characterized in that, The coating die head includes multiple first modules, second modules, and third modules. The second module is disposed between the multiple first modules and the third module. Each first module and the second module together form a first mold cavity, and the third module and the second module together form a second mold cavity. The coating method includes: After the substrate is unwound, it is moved to the coating die head by the transfer roller. The second die cavity extrudes the first coating material to coat the substrate, thereby forming the first coating layer on the substrate. Each of the first cavities extrudes a second coating material to coat the substrate coated with the first coating, thereby forming the second coating on the first coating.