Anode sheet, electrode assembly, electrochemical device, and electronic device
Patent Information
- Application Number
- CN202522071854.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-26
- Publication Date
- 2026-10-27
- Estimated Expiration
- 2035-09-26
AI Technical Summary
[0003]相关技术中，极片的单双面交界处较容易产生析锂现象
本申请实施例的方案中，沿阳极片的长度方向，第一活性物质层的尺寸大于第二活性物质层的尺寸，第二活性物质层与第一活性物质层之间形成有单双面交界处，在第一活性物质层与第二活性物质层形成有孔槽的情况下，孔槽处的可能出现电流密度过大的情况，而在孔槽的内部涂覆有固态电解质能够降低孔槽处的电流密度，减少锂离子析出，从而减少单双面交界处产生析锂现象的情况。再者，固态电解质能够与第一活性物质层或者第二活性物质层发生反应，固态电解质能够作为锂源提升能量密度。
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Figure CN224907982U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to an anode sheet, electrode assembly, electrochemical device, and electronic device. Background Technology
[0002] With the development of new energy sources, more and more fields are adopting them as power sources. Due to their advantages such as high energy density, rechargeability, safety, and environmental friendliness, electrochemical devices are widely used in new energy vehicles, consumer electronics, and energy storage systems. Typically, to increase the energy density of the battery cell, a large amount of active material is coated, resulting in excessive anode surface density and a higher likelihood of lithium plating at the interface. The industry addresses this problem by drilling holes in the anode surface to improve the lithium-ion transport rate.
[0003] In related technologies, lithium plating is more likely to occur at the junction of single and double sides of the electrode. Utility Model Content
[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an anode sheet, electrode assembly, electrochemical device, and electronic device that can reduce lithium plating at the single-sided and double-sided interface of the electrode sheet.
[0005] The anode sheet according to a first aspect embodiment of this application includes: The first current collector has a first surface and a second surface opposite to each other along the thickness direction of the anode sheet; A first active material layer is attached to the first surface; A second active material layer is attached to the second surface along the length of the anode sheet. The size of the second active material layer is smaller than that of the first active material layer. The length direction of the anode sheet is perpendicular to the thickness direction of the anode sheet. The first active material layer and the second active material layer have a plurality of pores extending along a first direction, which is perpendicular to both the length direction and the thickness direction of the anode sheet, and at least one of the pores is coated with a solid electrolyte.
[0006] The anode sheet according to the embodiments of this application has at least the following beneficial effects: In the embodiment of this application, along the length of the anode sheet, the size of the first active material layer is larger than the size of the second active material layer. A single- or double-sided interface is formed between the second and first active material layers. When a groove is formed between the first and second active material layers, the current density at the groove may be too high. Coating the inside of the groove with a solid electrolyte can reduce the current density at the groove, reduce lithium ion deposition, and thus reduce lithium deposition at the single- or double-sided interface. Furthermore, the solid electrolyte can react with either the first or second active material layer, and can act as a lithium source to increase energy density.
[0007] According to some embodiments of this application, the pores corresponding to the first active material layer are first pores, the pores corresponding to the second active material layer are second pores, and the solid electrolyte is coated inside at least one first pore and at least one second pore.
[0008] According to some embodiments of this application, at least one of the first active material layer and the second active material layer has a coating portion, the groove corresponding to the coating portion is coated with the solid electrolyte, the second surface of the first current collector has an empty foil area, the empty foil area is adjacent to the second active material layer and projected along the thickness direction of the anode sheet, and the projection area of the coating portion is adjacent to the projection area of the empty foil area.
[0009] According to some embodiments of this application, along the length direction of the anode sheet, the size of the coated portion is greater than or equal to 10 mm and less than or equal to 20 mm.
[0010] According to some embodiments of this application, both the first active material layer and the second active material layer have the coating portion. When projected along the thickness direction of the anode sheet, the projected area of the coating portion corresponding to the first active material layer overlaps with the projected area of the coating portion corresponding to the second active material layer.
[0011] According to some embodiments of this application, along the first direction, the size of the pore groove is L1, and the size of the solid electrolyte corresponding to a single pore groove is L2, wherein L2 is greater than or equal to L1, and L2 is less than or equal to L1 + 0.3 mm; and / or, Along the length of the anode plate, the size of the perforation is W1, and the size of the solid electrolyte corresponding to a single perforation is W2, wherein W2 is greater than or equal to W1, and W2 is less than or equal to W1 + 0.2 mm; and / or, Along the thickness direction of the anode plate, the size of the pore is H1, and the size of the solid electrolyte corresponding to a single pore is H2, wherein H2 is greater than or equal to H1, and H2 is less than or equal to H1+3μm.
[0012] According to some embodiments of this application, the solid electrolyte is lithium aluminum titanium phosphate or lithium lanthanum zirconium oxide.
[0013] A second aspect of this application provides an electrode assembly, comprising: Anode plates of any of the above; A diaphragm is attached to the anode plate; A cathode sheet is attached to the diaphragm, which is disposed between the anode sheet and the cathode sheet.
[0014] A third aspect of this application provides an electrochemical device, comprising: case; The electrode assembly of any of the above, wherein the electrode assembly is located within the housing.
[0015] A third aspect of this application provides an electronic device, comprising: Equipment body; The electrochemical device described above is used to supply power to the main body of the device.
[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0017] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a simplified structural diagram of the anode sheet in one embodiment of this application; Figure 2 This is a simplified structural diagram of the anode sheet in one embodiment of this application; Figure 3 for Figure 2 A local method diagram at position A in the middle.
[0018] Figure label: 100, First current collector; 100a, First surface; 100b, Second surface; 100c, Coated portion; 100d, Empty foil area; 200, First active material layer; 200a, First pore; 300, Second active material layer; 300a, Second pore; 400, Solid electrolyte. Detailed Implementation
[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0020] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying 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.
[0021] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.
[0022] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0023] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0024] Currently, judging from market trends, the application of electrochemical devices is becoming increasingly widespread. Electrochemical devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely applied in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of the application areas of electrochemical devices, the market demand is also constantly increasing.
[0025] In related technologies, to increase the energy density of the battery cell, a larger amount of active material is coated, resulting in excessive density on the anode sheet. To reduce lithium plating at the interface, holes are drilled on the anode sheet surface to improve the lithium-ion transport rate. However, due to the drilling at the single-sided / double-sided interface of the electrode, the local current density becomes excessively high, making lithium plating more likely to occur at this location.
[0026] In this embodiment, the first active material layer 200 and the second active material layer 300 of the anode sheet are coated with a solid electrolyte 400. The solid electrolyte 400 can reduce the current density at the holes, thereby reducing lithium ion deposition and further reducing lithium deposition at the single-sided / double-sided interface.
[0027] This application provides an electronic device, which includes a device body and an electrochemical device for supplying power to the device body.
[0028] Electronic devices can be, for example, mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft.
[0029] The technical solutions described in the embodiments of this application are not limited to the devices described above, but can also be applied to all devices that use electrochemical devices.
[0030] The electrochemical devices mentioned in the embodiments of this application may include one or more electrochemical device assemblies for providing voltage and capacity. An electrochemical device assembly may include multiple electrochemical devices, which are connected in series, parallel, or mixed configurations via a busbar.
[0031] In some embodiments, the electrochemical device assembly is typically formed by arranging multiple electrochemical devices.
[0032] As an example, the electrochemical device assembly can be a battery module, which consists of multiple electrochemical devices arranged and fixed together to form a single module. As another example, a battery module can be formed by bundling multiple electrochemical devices together with cable ties.
[0033] In some embodiments, the electrochemical device may be a battery pack, which includes a housing and one or more electrochemical device components housed within the housing.
[0034] This application also provides a battery pack, which includes a housing and at least one electrochemical device located inside the housing.
[0035] In some embodiments of this application, the electrochemical device can be a secondary battery, which refers to an electrochemical device that can be used again after being discharged by recharging to activate the active material.
[0036] The electrochemical device can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.
[0037] This application provides an anode sheet; please refer to [link / reference]. Figure 1 and Figure 2 The anode sheet includes a first current collector 100, a first active material layer 200, and a second active material layer 300. Exemplarily, the thickness directions of the first current collector 100, the first active material layer 200, and the second active material layer 300 are all arranged parallel to the thickness direction of the anode sheet. Exemplarily, the first current collector 100 is a metal foil or a composite current collector. In some embodiments, the metal foil is a copper foil. The composite current collector may include a metal foil substrate and a conductive layer disposed on at least one side of the metal foil substrate. In some embodiments, the conductive layer may include at least one of carbon, carbon black, graphite, expanded graphite, graphene, graphene nanosheets, carbon fibers, carbon nanofibers, graphitized carbon sheets, carbon nanotubes, carbon nanotubes, activated carbon, and mesoporous carbon. The first current collector 100 has a first surface 100a and a second surface 100b opposite each other along the thickness direction of the anode sheet. The first active material layer 200 is attached to the first surface 100a. The second active material layer 300 is attached to the second surface 100b. Along the length of the anode sheet, the size of the second active material layer 300 is smaller than the size of the first active material layer 200. The length direction of the anode sheet is perpendicular to its thickness direction. The first active material layer 200 and the second active material layer 300 have multiple slots extending along a first direction. The first active material layer 200 and the second active material layer 300 are recessed in the direction toward the first current collector 100 to form these slots. These slots can be formed by laser processing. The first direction is perpendicular to both the length direction and the thickness direction of the anode sheet. For example, the first direction... Figure 1 The direction indicated by the middle arrow R1 is the length direction of the anode plate as follows: Figure 1 The direction indicated by the middle arrow R2 is the thickness direction of the anode sheet. Figure 2 In the direction indicated by the middle arrow R3, at least one cavity is coated with a solid electrolyte 400.
[0038] In the embodiment of this application, along the length of the anode sheet, the size of the first active material layer 200 is larger than the size of the second active material layer 300. A single- or double-sided interface is formed between the second active material layer 300 and the first active material layer 200. When a groove is formed between the first active material layer 200 and the second active material layer 300, the current density at the groove may be too high. Coating the inside of the groove with a solid electrolyte 400 can reduce the current density at the groove, reduce lithium ion deposition, and thus reduce lithium deposition at the single- or double-sided interface. Furthermore, the solid electrolyte 400 can react with either the first active material layer 200 or the second active material layer 300, and can act as a lithium source to increase energy density.
[0039] In one embodiment, please refer to Figure 2 The pores corresponding to the first active material layer 200 are designated as first pores 200a, and the pores corresponding to the second active material layer 300 are designated as second pores 300a. Exemplarily, there are multiple first pores 200a and multiple second pores 300a, with the first pores 200a and the second pores 300a arranged at intervals along the length of the anode sheet. At least one first pore 200a and at least one second pore 300a are coated with a solid electrolyte 400. Since both the first pores 200a and the second pores 300a are coated with solid electrolyte 400, the solid electrolyte 400 can improve the current density within the first active material layer 200 and the second active material layer 300, thereby reducing the occurrence of lithium plating within the first active material layer 200 and the second active material layer 300.
[0040] It is understood that other embodiments of this application are not limited to having a solid electrolyte 400 inside at least one first pore 200a and at least one second pore 300a. Exemplarily, the interior of the first pore 200a or the second pore 300a is coated with a solid electrolyte 400.
[0041] In one embodiment, please refer to Figure 2At least one of the first active material layer 200 and the second active material layer 300 has a coating portion 100c, and the corresponding groove of the coating portion 100c is coated with a solid electrolyte 400. Exemplarily, the coating portion 100c extends along the length direction of the anode sheet. When both the first groove 200a and the second groove 300a are coated with solid electrolyte 400, both the first active material layer 200 and the second active material layer 300 have a coating portion 100c. The second surface 100b of the first current collector 100 has an empty foil region 100d, which is adjacent to the second active material layer 300. Projected along the thickness direction of the anode sheet, the projection area of the coating portion is adjacent to the projection area of the empty foil region 100d. Exemplarily, along the thickness direction of the anode sheet, the portion opposite the empty foil region 100d is a portion of the first active material layer 200. Projected along the thickness direction of the anode sheet, the projection areas of the empty foil region 100d and the second active material layer 300 overlap with the projection areas of the first active material layer 200. It is understandable that the adjacentity between the projected area of the coated part and the projected area of the empty foil area 100d means that the boundary of the projected area of the coated part is adjacent to the boundary of the projected area of the empty foil area 100d, or they may overlap. Placing the coated part as close as possible to the empty foil area 100d can minimize the occurrence of lithium plating at the single-sided / double-sided interface, thereby increasing the service life of the corresponding electrochemical device.
[0042] In one embodiment, please refer to Figure 2 Along the length of the anode sheet, the size of the coated portion is greater than or equal to 10 mm and less than or equal to 20 mm. For example, the size of the coated portion along the length of the anode sheet is 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, or 20 mm. It is understood that the size of the coated portion can be obtained by measuring it with a ruler under normal temperature and pressure. Maintaining the size of the coated portion within a suitable range allows the pores coated with the solid electrolyte 400 to cover the single- and double-sided interface thinning area as much as possible, while also controlling the manufacturing cost of the anode sheet as much as possible.
[0043] In one embodiment, please refer to Figure 2 Both the first active material layer 200 and the second active material layer 300 have coating portions. Projected along the thickness direction of the anode sheet, the projected areas of the coating portions corresponding to the first active material layer 200 and the second active material layer 300 overlap. The coating portions corresponding to the first active material layer 200 and the second active material layer 300 are flush along the thickness direction of the anode sheet, which allows the lithium-ion migration rates at corresponding positions of the first active material layer 200 and the second active material layer 300 along the thickness direction to match, thereby minimizing lithium plating on the anode sheet.
[0044] In one embodiment, please refer to Figure 2 and Figure 3 Along the first direction, the size of the perforation is L1, and the size of the solid electrolyte 400 corresponding to a single perforation is L2, where L2 is greater than or equal to L1, and L2 is less than or equal to L1 + 0.3 mm. Along the length direction of the anode plate, the size of the perforation is W1, and the size of the solid electrolyte 400 corresponding to a single perforation is W2, where W2 is greater than or equal to W1, and W2 is less than or equal to W1 + 0.2 mm. Along the thickness direction of the anode plate, the size of the perforation is H1, and the size of the solid electrolyte 400 corresponding to a single perforation is H2, where H2 is greater than or equal to H1, and H2 is less than or equal to H1 + 3 μm. The dimensions W2 and H2 are as follows: Figure 3 As shown, the size of the solid electrolyte 400 corresponding to a single hole is larger than the size of the corresponding hole in the first direction, the length direction of the anode plate, and the thickness direction of the anode plate. The solid electrolyte 400 can completely cover the corresponding hole, thereby further reducing the occurrence of lithium plating at the hole.
[0045] In one embodiment, the solid electrolyte 400 is lithium aluminum titanium phosphate (LATP) or lithium lanthanum zirconium oxide (LLZO). Both lithium aluminum titanium phosphate and lithium lanthanum zirconium oxide are oxide solid electrolytes 400, which have high stability and can remain stable at high temperatures. Furthermore, the solid electrolyte 400 has the characteristic of high energy density, which can increase the energy density of the electrode assembly to a certain extent.
[0046] Embodiments of this application also provide an electrode assembly, which includes an anode sheet, a diaphragm, and a cathode sheet as described above. The diaphragm is attached to the anode sheet, the cathode sheet is attached to the diaphragm, and the diaphragm is disposed between the anode sheet and the cathode sheet. Exemplarily, the electrode assembly is a wound battery cell.
[0047] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of the specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of protection.
Claims
1. An anode plate, characterized in that, include: The first current collector has a first surface and a second surface opposite to each other along the thickness direction of the anode sheet; A first active material layer is attached to the first surface; A second active material layer is attached to the second surface along the length of the anode sheet. The size of the second active material layer is smaller than that of the first active material layer. The length direction of the anode sheet is perpendicular to the thickness direction of the anode sheet. The first active material layer and the second active material layer have a plurality of pores extending along a first direction, which is perpendicular to both the length direction and the thickness direction of the anode sheet, and at least one of the pores is coated with a solid electrolyte.
2. The anode plate according to claim 1, characterized in that, The pores corresponding to the first active material layer are called first pores, and the pores corresponding to the second active material layer are called second pores. The solid electrolyte is coated inside at least one first pore and at least one second pore.
3. The anode plate according to claim 1, characterized in that, At least one of the first active material layer and the second active material layer has a coating portion, and the solid electrolyte is coated on the groove corresponding to the coating portion. The second surface of the first current collector has an empty foil area, which is adjacent to the second active material layer and projected along the thickness direction of the anode sheet. The projection area of the coating portion is adjacent to the projection area of the empty foil area.
4. The anode sheet according to claim 3, characterized in that, Along the length of the anode sheet, the size of the coated portion is greater than or equal to 10 mm and less than or equal to 20 mm.
5. The anode plate according to claim 3, characterized in that, Both the first active material layer and the second active material layer have the coating portion. When projected along the thickness direction of the anode sheet, the projected area of the coating portion corresponding to the first active material layer overlaps with the projected area of the coating portion corresponding to the second active material layer.
6. The anode plate according to claim 1, characterized in that, Along the first direction, the size of the pore is L1, and the size of the solid electrolyte corresponding to a single pore is L2, wherein L2 is greater than or equal to L1, and L2 is less than or equal to L1 + 0.3 mm; and / or, Along the length of the anode plate, the size of the perforation is W1, and the size of the solid electrolyte corresponding to a single perforation is W2, wherein W2 is greater than or equal to W1, and W2 is less than or equal to W1 + 0.2 mm; and / or, Along the thickness direction of the anode plate, the size of the pore is H1, and the size of the solid electrolyte corresponding to a single pore is H2, wherein H2 is greater than or equal to H1, and H2 is less than or equal to H1+3μm.
7. The anode plate according to claim 1, characterized in that, The solid electrolyte is lithium aluminum titanium phosphate or lithium lanthanum zirconium oxide.
8. An electrode assembly, characterized in that, include: The anode sheet as described in any one of claims 1 to 7; A diaphragm is attached to the anode plate; A cathode sheet is attached to the diaphragm, which is disposed between the anode sheet and the cathode sheet.
9. An electrochemical device, characterized in that, include: case; The electrode assembly as claimed in claim 8, wherein the electrode assembly is located within the housing.
10. An electronic device, characterized in that, include: Equipment body; At least one electrochemical device as described in claim 9, wherein the electrochemical device is used to supply power to the main body of the device.