Pole piece structure, battery cell and battery
By introducing an inert coating and active material layer into the electrode sheet structure of the lithium-ion battery, the hardness of the single-sided area is improved, and the problem of deformation and wrinkling of the current collector during the rolling process is solved, and the safety and stability of the battery cell are improved.
Patent Information
- Application Number
- CN202420160420.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-23
- Publication Date
- 2025-02-28
- Estimated Expiration
- 2034-01-23
AI Technical Summary
The current collector of existing lithium-ion batteries is prone to deformation and wrinkle during rolling, resulting in unstable structure and affecting the performance and safety of the battery cell.
An electrode sheet structure is adopted, including a current collector, a single-sided area, an empty foil area and a double-sided area. A first and second active material layers are provided on the double-sided area, and a third active material layer and an inert coating are provided on the single-sided area. The hardness of the single-sided area is improved through the conductive properties and filling and fixing properties of the inert coating to avoid deformation of the current collector.
It effectively avoids deformation of the current collector during the rolling process, improves the rolling wrinkle problem in the single-sided area of the anode sheet, improves the safety and stability of the battery cell, and avoids problems such as lithium cell separation.
Smart Images
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Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a pole piece structure, a battery core and a battery. Background Art
[0002] As a secondary battery, lithium-ion batteries are widely used in 3C digital products such as mobile phones, mobile power supplies, and smart wearables. They are also rapidly developing and being used in solar street light energy storage and new energy vehicle power batteries. And with the rapid development of lithium-ion batteries, while consumer batteries are pursuing fast charging capabilities and energy density, the safety performance of the battery cells is also receiving more and more attention. It is necessary to improve the safety performance of the battery cells from multiple aspects such as the current collector, matching system, and battery cell structure.
[0003] In terms of current collectors, this goal is generally achieved by increasing the thickness and elongation of copper foil. However, as the elongation increases, the copper foil becomes softer and is easily deformed after rolling, resulting in wrinkles, which affects the structural stability of the current collector, which in turn seriously affects the process efficiency and battery performance. Utility Model Content
[0004] The purpose of the utility model is to provide a pole piece structure, a battery cell and a battery in view of the deficiencies in the prior art, so as to improve the safety and stability of use.
[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A pole piece structure comprises a current collector; a single-sided area, a hollow foil area and at least one double-sided area are provided on the current collector; a first active material layer and a second active material layer are arranged oppositely on the current collector in the double-sided area, and a third active material layer and an inert coating are arranged oppositely on the current collector in the single-sided area.
[0007] Preferably, the relationship between the thickness L1 of the inert coating layer and the thickness L2 of the third active material layer satisfies: L1≤L2.
[0008] Preferably, the relationship among the thickness L2 of the third active material layer, the thickness L3 of the first active material layer and the thickness L4 of the second active material layer satisfies: L2=L3=L4.
[0009] Preferably, the relationship between the projection area S1 of the inert coating toward the current collector and the coverage area S0 of the single-sided area toward the current collector satisfies: S1≤S0.
[0010] Preferably: the inert coating comprises an inert coating segment and a blank segment; and the projection of the third active material layer onto the current collector covers the inert coating segment; the projection of the third active material layer onto the current collector covers the blank segment.
[0011] Preferably, the inert coating is selected from one of a ceramic coating, an alumina coating and a boehmite coating.
[0012] Preferably: a first blank layer and a second blank layer which are arranged opposite to each other are also provided on the current collector in the empty foil area; and the first blank layer is located between the first active material layer and the third active material layer; and the second blank layer is located between the second active material layer and the inert coating.
[0013] Preferably, the relationship between the projection area S2 of the first blank layer toward the current collector and the projection area S3 of the second blank layer toward the current collector satisfies: S2=S3.
[0014] The utility model also discloses a battery core, comprising a positive electrode sheet and a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet and / or the negative electrode sheet is the electrode sheet structure.
[0015] The utility model also discloses a battery, comprising the battery core.
[0016] The beneficial effect of the utility model is that the technical solution can increase the hardness and other properties of the corresponding position of the single-sided area by adopting the conductive properties and filling and fixing properties of the inert coating as much as possible, thereby effectively avoiding the deformation of the current collector by the "secondary processing" of the roller, thereby achieving the purpose of improving the rolling wrinkling of the single-sided area of the anode sheet; and improving the safety and stability of use, which is conducive to avoiding problems such as lithium plating in the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following will refer to the attached Figures 1 to 6 To describe the features, advantages and technical effects of exemplary embodiments of the present utility model.
[0018] Figure 1 This is a schematic structural diagram of a pole piece structure according to an embodiment of the utility model;
[0019] Figure 2 This is a schematic structural diagram of a pole piece structure according to an embodiment of the utility model;
[0020] Figure 3 A schematic diagram of the structure of an inert coating of a pole piece structure of one embodiment of the utility model;
[0021] Figure 4A schematic diagram of the structure of an inert coating of a pole piece structure according to another embodiment of the utility model;
[0022] Figure 5 A schematic diagram of the structure of an inert coating of a pole piece structure according to another embodiment of the utility model;
[0023] Figure 6 This is a schematic structural diagram of an inert coating of a pole piece structure according to another embodiment of the utility model.
[0024] In the figure: 1-current collector; 2-double-sided area; 21-first active material layer; 22-second active material layer; 3-empty foil area; 31-first blank layer; 32-second blank layer; 4-single-sided area; 41-third active material layer; 42-inert coating; 421-inert coating section; 422-blank section. DETAILED DESCRIPTION
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.
[0026] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.
[0027] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0028] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship between the pole piece structure, the battery cell and the battery to describe the associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and multiple situations exist alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are an "or" relationship between a pole piece structure, a battery cell and a battery.
[0029] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).
[0030] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.
[0031] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.
[0032] The following is combined with Figure 1 to Figure 6 The utility model is further described in detail, but it is not intended to limit the utility model.
[0033] like Figure 1 and 2 As shown, in one embodiment of the utility model, the pole piece structure includes a current collector 1; a single-sided area 4, a hollow foil area 3 and at least one double-sided area 2 are provided on the current collector 1; a first active material layer 21 and a second active material layer 22 arranged oppositely are also provided on the current collector 1 in the double-sided area 2; a third active material layer 41 and an inert coating 42 arranged oppositely are also provided on the current collector 1 in the single-sided area 4.
[0034] The technical solution of the utility model can increase the hardness and other properties of the corresponding position of the single-sided area by utilizing the conductive properties and filling and fixing properties of the inert coating as much as possible, thereby effectively avoiding the deformation of the current collector by the "secondary processing" of the roller, thereby achieving the purpose of improving the rolling wrinkling of the single-sided area of the anode sheet; and improving the safety and stability of use, which is conducive to avoiding problems such as lithium plating in the battery cell.
[0035] Wherein, in some embodiments, Figure 1As shown, the number of double-sided regions 2 is two; one double-sided region 2 is arranged at the side end of the empty foil region 3, and is arranged at the two side ends of the empty foil region 3 opposite to the single-sided region 4; the other double-sided region 2 is arranged at the side end of the single-sided region 4, and is arranged at the two side ends of the single-sided region 4 opposite to the empty foil region 3. That is to say, the current collector 1 is sequentially provided with another double-sided region 2, the single-sided region 4, the empty foil region 3 and one of the double-sided regions 2; and one of the double-sided regions 2 is at the end of the tail section in the pole piece structure. Among them, in some embodiments, the materials selected for the first active material layer 21, the second active material layer 22 and the third active material layer 41 are the same. That is to say, both sides of the current collector 1 are coated with active coatings, one side covers a larger area, and the other side covers a smaller area; and an inert coating 42 is added to the other side with a smaller covered area to prevent the current collector 1 from being deformed by the "secondary processing" of the roller, thereby achieving the purpose of improving the rolling wrinkling of the single-sided area of the anode sheet.
[0036] Specifically, in some embodiments, the inert coating 42 is selected from one of a ceramic coating, an alumina coating, and a boehmite coating. One of the ceramic coating, the alumina coating, and the boehmite coating can significantly improve the thermal stability of the current collector 1, thereby improving the safety of the lithium-ion battery, and can improve the rate performance and cycle performance of the battery. At the same time, a thinner coating thickness helps to improve the volume energy density and weight energy density of the lithium-ion battery.
[0037] Specifically, in some embodiments, Figure 2 As shown, the relationship between the thickness L1 of the inert coating 42 and the thickness L2 of the third active material layer 41 satisfies: L1≤L2. This structure can adjust the overall thickness of the battery cell by controlling the coating thickness parameter, thereby helping to improve the volume energy density and weight energy density of the lithium-ion battery.
[0038] Specifically, in some embodiments, Figure 2 As shown, the relationship between the thickness L2 of the third active material layer 41, the thickness L3 of the first active material layer 21, and the thickness L4 of the second active material layer 22 satisfies: L2=L3=L4.
[0039] Specifically, in some embodiments, the relationship between the projection area S1 of the inert coating 42 toward the current collector 1 and the coverage area S0 of the single-sided area 4 toward the current collector 1 satisfies: S1≤S0. That is, the coating area of the inert coating 42 accounts for 0% to 100% of the entire area of the single-sided area 4. This structure can adjust the overall weight of the battery cell by controlling the parameter of the coating coverage area, thereby helping to improve the volume energy density and weight energy density of the lithium-ion battery.
[0040] Specifically, in one embodiment, Figure 3As shown, the relationship between the projection area S1 of the inert coating 42 toward the current collector 1 and the coverage area S0 of the single-sided area 4 toward the current collector 1 satisfies: S1 = S0. This structure can effectively simplify the coating operation process and improve processing efficiency.
[0041] Specifically, in some embodiments, the inert coating 42 includes an inert coating segment 421 and a blank segment 422; and the projection of the third active material layer 41 onto the current collector 1 covers the inert coating segment 421; and the projection of the third active material layer 41 onto the current collector 1 covers the blank segment 422. The number of the inert coating segments 421 is at least two, and the number of the blank segments 422 is at least two; and the inert coating segments 421 and the blank segments 422 are alternately arranged. Further, as Figure 4 As shown, the inert coating section 421 and the blank section 422 are alternately arranged in sequence along the length direction of the single-sided area 4. Figure 5 As shown, the inert coating segments 421 and the blank segments 422 are alternately arranged in sequence along the width direction of the single-sided area 4. In other embodiments, as Figure 6 As shown, the inert coating segment 421 is located inside the blank segment 422 , and the inert coating segment 421 is arranged in a slanted and parallel manner in the single-sided area 4 or in a scattered manner in the single-sided area 4 ; so that the blank segment 422 separates two adjacent inert coating segments 421 .
[0042] Specifically, in some embodiments, Figure 1 As shown, the current collector 1 in the empty foil area 3 is also provided with a first blank layer 31 and a second blank layer 32 arranged opposite to each other; and the first blank layer 31 is located between the first active material layer 21 and the third active material layer 41; the second blank layer 32 is located between the second active material layer 22 and the inert coating 42; and the first active material layer 21 and the second active material layer 22 are arranged opposite to each other at the two side ends of the same double-sided area 2. Figure 1 and 2 As shown, the relationship between the projection area S2 of the first blank layer 31 toward the current collector 1 and the projection area S3 of the second blank layer 32 toward the current collector 1 satisfies: S2 = S3. This structure can achieve the coating area of the two sides of the current collector 1 to be as equal as possible, and can effectively improve the structural stability of the current collector 1, so that the current collector 1 can be protected from the deformation of the "secondary processing" of the roller, thereby achieving the purpose of improving the rolling wrinkling of the single-side area of the anode sheet.
[0043] The utility model also proposes a battery cell, which includes a positive electrode sheet and a negative electrode sheet and an isolation membrane arranged between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet and / or the negative electrode sheet is a electrode sheet structure, and the specific structure of the electrode sheet structure refers to the above-mentioned embodiment. Since the battery cell adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.
[0044] The battery cell or battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode collector; the positive electrode collector includes a positive electrode coating area and a positive electrode ear connected to the positive electrode coating area, the positive electrode coating area is coated with a positive electrode active material layer, and the positive electrode ear is not coated with a positive electrode active material layer.
[0045] The utility model also proposes a battery, which includes a battery cell. The specific structure of the battery cell refers to the above embodiment. Since the battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.
[0046] Among them, battery refers to a cup, trough or other container or part of a composite container that contains electrolyte solution and metal electrodes to generate current, and is a device that can convert chemical energy into electrical energy; the battery has positive and negative electrodes. With the advancement of science and technology, batteries generally refer to small devices that can generate electrical energy, such as solar cells. The performance parameters of batteries mainly include electromotive force, capacity, specific energy and resistance. Battery principle: In chemical batteries, the direct conversion of chemical energy into electrical energy is the result of spontaneous oxidation, reduction and other chemical reactions inside the battery, which are carried out on the two electrodes respectively. The negative electrode active material is composed of a reducing agent with a relatively negative potential and stable in the electrolyte, such as active metals such as zinc, cadmium, and lead, and hydrogen or hydrocarbons. The positive electrode active material is composed of an oxidizing agent with a relatively positive potential and stable in the electrolyte, such as metal oxides such as manganese dioxide, lead dioxide, and nickel oxide, oxygen or air, halogens and their salts, oxygen-containing acids and their salts, etc. The electrolyte is a material with good ionic conductivity, such as an aqueous solution of acid, alkali, or salt, an organic or inorganic non-aqueous solution, a molten salt, or a solid electrolyte.
[0047] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
[0048] According to the disclosure and teaching of the above description, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the above specific implementation, and any obvious improvement, replacement or modification made by the technicians in this field on the basis of the utility model belongs to the protection scope of the utility model. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the utility model.
Claims
1. A pole piece structure, characterized in that: It comprises a current collector; a single-sided area, a hollow foil area and at least one double-sided area are provided on the current collector; a first active material layer and a second active material layer arranged oppositely are also provided on the current collector in the double-sided area, and a third active material layer and an inert coating arranged oppositely are also provided on the current collector in the single-sided area.
2. The pole piece structure according to claim 1, characterized in that: The relationship between the thickness L1 of the inert coating layer and the thickness L2 of the third active material layer satisfies: L1≤L2.
3. The pole piece structure according to claim 1 or 2, characterized in that: The relationship between the thickness L2 of the third active material layer, the thickness L3 of the first active material layer, and the thickness L4 of the second active material layer satisfies: L2=L3=L4.
4. The pole piece structure according to claim 1 or 2, characterized in that: The relationship between the projection area S1 of the inert coating toward the current collector and the coverage area S0 of the single-sided area toward the current collector satisfies: S1≤S0.
5. The pole piece structure according to claim 4, characterized in that: The inert coating layer includes an inert coating segment and a blank segment; and the projection of the third active material layer onto the current collector covers the inert coating segment; and the projection of the third active material layer onto the current collector covers the blank segment.
6. The pole piece structure according to claim 1, characterized in that: The inert coating is selected from one of a ceramic coating, an alumina coating and a boehmite coating.
7. The pole piece structure according to claim 1, characterized in that: A first blank layer and a second blank layer are arranged opposite to each other on the current collector in the empty foil area; the first blank layer is located between the first active material layer and the third active material layer; and the second blank layer is located between the second active material layer and the inert coating.
8. The pole piece structure according to claim 7, characterized in that: The relationship between the projection area S2 of the first blank layer toward the current collector and the projection area S3 of the second blank layer toward the current collector satisfies: S2=S3.
9. A battery cell, characterized in that: It comprises a positive electrode sheet and a negative electrode sheet and a separator arranged between the positive electrode sheet and the negative electrode sheet; the positive electrode sheet and / or the negative electrode sheet is the electrode sheet structure as described in any one of claims 1 to 8 above.
10. A battery, characterized in that: The battery cell comprises the battery cell as claimed in claim 9.