Battery cell pole piece structure, battery cell and battery
By setting up misaligned connectors in the electrode plate structure of the lithium-ion cell, the discount and wrinkle problems of the electrode plate structure during winding are solved, the stability and safety of the cell are improved, and the risk of lithium-ion cell separation is avoided.
Patent Information
- Application Number
- CN202422316718.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2034-09-23
AI Technical Summary
In the existing lithium-ion cell manufacturing process, the empty foil position on the head of the anode sheet and the diaphragm head are prone to discounts and wrinkles when wound, resulting in unevenness of the cell inside and affecting the stability and safety of use.
The pole piece structure is adopted with a blank area, a single-sided area and a double-sided area on the current collector, and the connecting parts are arranged in dislocation, including the first and second connecting parts on the blank area and a single-sided area respectively, so as to improve the tensile hardness through the dislocation design to avoid folding or wrinkling of the pole piece structure during the winding process.
The stability and safety of the electrode plate structure are improved, lithium-ion cell removal caused by changes in the deintercalation lithium path is avoided, and the tensile strength and use stability of the cell are enhanced.
Smart Images
Figure CN223296825U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of batteries, and in particular relates to a battery core pole piece structure, a battery core and a battery. Background Art
[0002] Winding remains the most widely used process for manufacturing lithium-ion batteries. However, during winding, the bare foil at the end of the anode sheet and the separator are prone to folding and wrinkling. This can lead to internal unevenness during hot pressing, and deformation of the wrinkled areas during cycling, compromising stability and safety. Utility Model Content
[0003] The purpose of the present invention is to provide a battery cell pole piece structure, a battery cell and a battery in view of the deficiencies in the prior art, which can solve the existing technical problems of low stability and safety.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A battery cell electrode structure includes a current collector, a first connector and a second connector; the current collector is provided with a blank area, a single-sided area and a double-sided area; the current collector located in the single-sided area has a first active material layer on one surface; the current collector located in the double-sided area has second active material layers on both sides; the first connector is connected to the current collector and is arranged in the blank area; the second connector is connected to the current collector and is arranged opposite to the first active material layer; and the projection of the first connector toward the current collector and the projection of the second connector toward the current collector are staggered.
[0006] Preferably, the projection of the second connecting member toward the current collector is completely disposed on a single-sided area of the current collector;
[0007] And / or, a misalignment region is provided between a projection of the first connector toward the current collector and a projection of the second connector toward the current collector; and a length L3 of the misalignment region satisfies: 0<L3.
[0008] Preferably, the relationship among the length L3 of the dislocation area, the length L4 of the single-sided area, the length L1 of the first connecting member and the length L2 of the second connecting member satisfies: L3≤L4-L1-L2.
[0009] Preferably, the length L4 of the single-sided area satisfies: 30 mm ≤ L4 ≤ 110 mm.
[0010] Preferably, the relationship among the length L4 of the single-sided area, the length L1 of the first connecting member, and the length L2 of the second connecting member satisfies: 10 mm ≤ L1 ≤ L2 < L4 − L1.
[0011] Preferably, the thickness D1 of the first connecting member and the thickness D2 of the first active material layer satisfy: D1≤D2;
[0012] And / or, the thickness D3 of the second connecting member and the thickness D4 of the second active material layer satisfy the following relationship: D3≤D4.
[0013] Preferably, the first connecting member is a first adhesive paper; and / or the second connecting member is a second adhesive paper.
[0014] The present utility model also discloses a battery cell, comprising a first pole piece, a second pole piece and an isolation membrane; the first pole piece, the isolation membrane and the second pole piece are stacked in sequence and wound to form a winding body; the first pole piece and / or the second pole piece is the above-mentioned battery cell pole piece structure.
[0015] Preferably, the winding body includes a head section, a middle section and a tail section connected in sequence; the first connecting member and the second connecting member are both arranged on the head section.
[0016] The utility model also discloses a battery, comprising the battery core.
[0017] The beneficial effect of the present invention is that the technical solution can improve the tensile hardness of the blank area and the single-sided area by adopting the first connector in the blank area at one end of the current collector and the second connector in the single-sided area; and combined with the first connector and the second connector that are staggered with each other, the thickness of the additional first connector or the second connector can be increased, thereby better improving the tensile hardness of the blank area and the single-sided area, and avoiding the phenomenon of folding or wrinkling in the blank area of the pole piece structure during the winding process, thereby improving the stability and safety of use, and avoiding the change of the lithium insertion and extraction path causing lithium plating in the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The following will refer to the attached Figures 1 to 3 To describe the features, advantages and technical effects of exemplary embodiments of the present invention.
[0019] Figure 1 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;
[0020] Figure 2 This is a schematic structural diagram of a battery cell electrode structure according to an embodiment of the present invention;
[0021] Figure 3This is a schematic structural diagram of a battery cell according to an embodiment of the present invention.
[0022] In the figure: 1-current collector; 101-blank area; 102-single-sided area; 103-double-sided area; 2-first active material layer; 3-second active material layer; 4-first connecting member; 401-offset area; 5-second connecting member; 100-first pole piece; 200-second pole piece; 300-isolating film; 601-tail section; 602-middle section; 603-head section; 700-winding body. DETAILED DESCRIPTION
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art 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" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.
[0024] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.
[0025] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0026] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or multiple situations exist. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.
[0027] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.
[0028] The following is combined with Figures 1 to 3 The present invention is further described in detail, but is not intended to limit the present invention.
[0029] like Figure 1 As shown, in one embodiment of the present invention, the battery cell electrode structure includes a current collector 1, a first connector 4, and a second connector 5. The current collector 1 is sequentially provided with a blank area 101, a single-sided area 102, and a double-sided area 103. The current collector 1 located in the single-sided area 102 has a first active material layer 2 on one side thereof; the current collector 1 located in the double-sided area 103 has a second active material layer 3 on both sides thereof. The first connector 4 is connected to the current collector 1 and is disposed in the blank area 101. The second connector 5 is connected to the current collector 1 and is disposed opposite to the first active material layer 2. The projection of the first connector 4 toward the current collector 1 and the projection of the second connector 5 toward the current collector 1 are staggered. The first active material layer 2 and the second active material layer 3 are integrally formed on the same side of the current collector 1.
[0030] The technical solution of the present invention can improve the tensile hardness of the blank area and the single-sided area by adopting a first connector in the blank area at one end of the current collector and a second connector in the single-sided area; and combined with the first connector and the second connector that are staggered with each other, the thickness of the additional first connector or the second connector can be increased, thereby better improving the tensile hardness of the blank area and the single-sided area, and avoiding folding or wrinkling in the blank area of the pole piece structure during the winding process, thereby improving the stability and safety of the structure, and avoiding changes in the lithium insertion and extraction path causing lithium plating in the battery cell.
[0031] Specifically, in some embodiments, the first connector 4 is a first adhesive paper, which may be green adhesive paper. And / or, the second connector 5 is a second adhesive paper, which may be green adhesive paper. This structure, by attaching the second adhesive paper to a single-sided area at one end of the pole piece structure and the first adhesive paper to a blank area, can ensure insulation between the pole piece structure and other components, reduce material costs, and increase the strength of the blank area, facilitating folding during winding, thereby avoiding folding and wrinkling.
[0032] Specifically, in some embodiments, Figure 1 and 2 As shown, the projection of the second connector 5 toward the current collector 1 is completely disposed on the single-sided area 102 of the current collector 1. In other words, to ensure smooth winding and folding and avoid folding and wrinkling, the length of the second connector 5 needs to be controlled to be less than or equal to the length of the first active material layer 2 in the single-sided area 102.
[0033] Specifically, in some embodiments, Figure 1 and 2 As shown, a staggered region 401 is provided between the projection of the first connector 4 toward the current collector 1 and the projection of the second connector 5 toward the current collector 1; and the length L3 of the staggered region 401 satisfies the following: 0 < L3. This structure, with staggered regions 401 and gaps between them, effectively prevents loss of cell thickness margin due to tape overlap.
[0034] Specifically, in some embodiments, Figure 1 and 2 As shown, the relationship between the length L3 of the offset region 401, the length L4 of the single-sided area 102, the length L1 of the first connector 4, and the length L2 of the second connector 5 satisfies the following equation: L3 ≤ L4 - L1 - L2. This structure achieves this by staggering the two non-overlapping tape cuts while maintaining the corresponding length relationships. This improves the hardness of the blank area 101 and the single-sided area 102, thereby enhancing the stability and safety of the structure and preventing changes in the lithium insertion and extraction pathways that could cause lithium deposition in the battery cell.
[0035] Specifically, in some embodiments, Figure 2 As shown, the length L4 of the single-sided area 102 satisfies the following conditions: 30mm≤L4≤110mm. This structure, with the appropriate length of the single-sided area 102, ensures the ease of assembly of the second adhesive tape and the hardness of the single-sided area 102, thereby improving the stability and safety of the structure and preventing changes in the lithium insertion and extraction pathways that could cause lithium deposition in the battery cell.
[0036] Specifically, in some embodiments, Figure 2As shown, the relationship between the length L4 of the single-sided area 102, the length L1 of the first connector 4, and the length L2 of the second connector 5 satisfies the following equation: 10mm ≤ L1 ≤ L2 < L4 - L1. This structure, by appropriately matching the lengths of the first connector 4 and the second connector 5, enhances the strength of the blank area 101 and the single-sided area 102, effectively preventing an increase in the thickness of the battery cell and the risk of wrinkling.
[0037] Specifically, in some embodiments, Figure 2 As shown, the thickness D1 of the first connector 4 and the thickness D2 of the first active material layer 2 satisfy the relationship D1 ≤ D2; the thickness D3 of the second connector 5 and the thickness D4 of the second active material layer 3 satisfy the relationship D3 ≤ D4. This structure, through the appropriate thickness of the first connector 4, second connector 5, first active material layer 2, and second active material layer 3, ensures the uniformity of the overall thickness of the electrode structure, avoids increasing the thickness of the battery cell, and effectively reduces the risk of wrinkling.
[0038] The present invention also provides a battery cell, such as Figure 3 As shown, the battery cell includes a first electrode sheet 100, a second electrode sheet 200 and a separator 300; the first electrode sheet 100, the separator 300 and the second electrode sheet 200 are stacked in sequence and wound to form a winding body 700; the first electrode sheet 100 and / or the second electrode sheet 200 are a battery cell electrode sheet structure; the specific structure of the battery cell electrode sheet structure refers to the above embodiment. Since the present battery cell 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. Among them, the first electrode sheet 100 is a positive electrode sheet, and the second electrode sheet 200 is a negative electrode sheet; or the first electrode sheet 100 is a negative electrode sheet, and the second electrode sheet 200 is a positive electrode sheet. Further, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer connected to at least one side of the surface of the positive electrode current collector; the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer connected to at least one side of the surface of the negative electrode current collector. Furthermore, the positive electrode current collector can be made of aluminum, and the positive electrode active material layer includes a positive electrode active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode current collector can be made of copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon. The separator 300 can be made of PP (polypropylene) or PE (polyethylene).
[0039] Specifically, in some embodiments, Figure 3As shown, the winding body 700 includes a head section 603 (winding starting section), a middle section 602 and a tail section 601 connected in sequence; the first connector 4 and the second connector 5 are both arranged in the head section 603. Among them, the first connector 4 and the second connector 5 are both arranged in the head section 603 of the negative electrode sheet. That is to say, the first connector 4 (first adhesive tape) and the second connector 5 (second adhesive tape) are added to the blank area 101 and the single-sided area 102 of the negative electrode sheet (anode sheet) to avoid the deformation of the wrinkled area during the winding process of the negative electrode sheet (anode sheet); and the thickness of the additional adhesive tape is not increased by staggering; thereby improving the tensile strength of the empty foil area, thereby improving the stability and safety of use, and avoiding the change of the lithium insertion and extraction path causing lithium plating in the battery cell.
[0040] Example 1
[0041] A first connector 4 (first adhesive tape) is attached to the blank area 101 in the head section 603 of the anode sheet, and the length of the first connector 4 (first adhesive tape) is 12 mm; at the same time, a second connector 5 is attached to the single-sided area 102 in the head section 603 of the anode sheet, and the length of the second connector 5 (second adhesive tape) is 15 mm; at the same time, the length of the single-sided area 102 in the head section 603 of the anode sheet is 40 mm; then the electrode structure is wound on a winding machine, and the thickness of the bare cell is tested after winding; the bare cell is disassembled to check the folding condition of the anode sheet head and the condition of the adhesive tape.
[0042] Example 2
[0043] The difference between Example 2 and Example 1 is that the length of the first connecting member 4 (first adhesive tape) is 15 mm; the length of the second connecting member 5 (second adhesive tape) is 20 mm.
[0044] Example 3
[0045] The difference between Example 3 and Example 1 is that the length of the first connecting member 4 (first adhesive tape) is 16 mm; the length of the second connecting member 5 (second adhesive tape) is 20 mm.
[0046] Comparative Example 1
[0047] The difference between Comparative Example 1 and Example 1 is that the first connecting member 4 (first adhesive tape) is not attached to the blank area 101 in the head section 603 of the anode sheet; and the second connecting member 5 is not attached to the single-sided area 102 in the head section 603 of the anode sheet.
[0048] Comparative Example 2
[0049] The difference between Comparative Example 2 and Example 1 is that the length of the first connecting member 4 (first adhesive tape) is 25 mm; the length of the second connecting member 5 (second adhesive tape) is 15 mm.
[0050] Comparative Example 3
[0051] The difference between Comparative Example 3 and Example 1 is that the length of the first connecting member 4 (first adhesive tape) is 6 mm; the length of the second connecting member 5 (second adhesive tape) is 8 mm.
[0052] Comparative Example 4
[0053] The difference between Comparative Example 4 and Example 1 is that the length of the first connecting member 4 (first adhesive tape) is 25 mm; the length of the second connecting member 5 (second adhesive tape) is 25 mm.
[0054] Table 1 Performance parameters of all embodiments and comparative examples
[0055]
[0056] Result analysis:
[0057] 1. When the empty foil area of the anode head and the folded single-sided fabric area of the head are not glued, the wrinkle resistance of the empty foil area and the folded single-sided area is weak, and folds and wrinkles are prone to occur.
[0058] 2. The length parameters of the first adhesive tape in the blank area 101 and the second adhesive tape in the single-sided area are designed so that the adhesive length L1 of the blank area 101 of the head section 603 of the anode and the adhesive width L2 of the single-sided area satisfy: L1≤L2≤L4-L1, thereby achieving a suitable match between length and function; and enhancing the strength of the blank area 101 and the single-sided area, effectively avoiding an increase in the thickness of the battery cell, and effectively avoiding the risk of wrinkles.
[0059] The present invention also provides a battery, which includes a battery cell. The specific structure of the battery cell refers to the above embodiments. 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.
[0060] A battery refers to a cup, tank, or other container, or a portion of a composite container, that contains an electrolyte solution and metal electrodes to generate an electric current. It is a device capable of converting chemical energy into electrical energy. Batteries have positive and negative electrodes. With technological advancements, batteries have become a general term for small devices that can generate electrical energy, such as solar cells. Key battery performance parameters include electromotive force, capacity, specific energy, and resistance. Battery Principle: In chemical batteries, the direct conversion of chemical energy into electrical energy occurs through spontaneous chemical reactions within the battery, such as oxidation and reduction, which occur at the two electrodes. The negative electrode active material consists of a reducing agent with a relatively negative potential and is stable in the electrolyte, such as active metals like zinc, cadmium, and lead, and hydrogen or hydrocarbons. The positive electrode active material consists of an oxidizing agent with a relatively positive potential and is stable in the electrolyte, such as metal oxides like manganese dioxide, lead dioxide, and nickel oxide, oxygen or air, halogens and their salts, and oxygen-containing acids and their salts. The electrolyte is a material with good ionic conductivity, such as aqueous solutions of acids, bases, and salts, organic or inorganic non-aqueous solutions, molten salts, or solid electrolytes.
[0061] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method 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 methods that can be understood by those skilled in the art.
[0062] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.
Claims
1. A battery cell electrode structure, characterized by: It includes a current collector, a first connecting member and a second connecting member; a blank area, a single-sided area and a double-sided area are provided on the current collector; a first active material layer is provided on one surface of the current collector located in the single-sided area; a second active material layer is provided on both side surfaces of the current collector located in the double-sided area; the first connecting member is connected to the current collector and is arranged in the blank area; the second connecting member is connected to the current collector and is arranged opposite to the first active material layer; and the projection of the first connecting member toward the current collector and the projection of the second connecting member toward the current collector are staggered.
2. The battery cell electrode structure according to claim 1, characterized in that: The projection of the second connecting member toward the current collector is completely disposed on a single-side area of the current collector; And / or, a misalignment region is provided between a projection of the first connector toward the current collector and a projection of the second connector toward the current collector; and a length L3 of the misalignment region satisfies: 0<L3.
3. The battery cell electrode structure according to claim 2, characterized in that: The relationship between the length L3 of the dislocation area, the length L4 of the single-sided area, the length L1 of the first connecting member, and the length L2 of the second connecting member satisfies: L3≤L4-L1-L2.
4. The battery cell electrode structure according to claim 1 or 3, characterized in that: The length L4 of the single-sided area satisfies: 30mm≤L4≤110mm.
5. The battery cell electrode structure according to claim 1 or 3, characterized in that: The relationship between the length L4 of the single-sided area, the length L1 of the first connecting member, and the length L2 of the second connecting member satisfies the following formula: 10 mm ≤ L1 ≤ L2 < L4 − L1.
6. The battery cell electrode structure according to claim 1 or 3, characterized in that: The thickness D1 of the first connecting member and the thickness D2 of the first active material layer satisfy: D1≤D2; And / or, the thickness D3 of the second connecting member and the thickness D4 of the second active material layer satisfy: D3≤D4.
7. The battery cell electrode structure according to claim 1, characterized in that: The first connecting member is a first adhesive paper; and / or the second connecting member is a second adhesive paper.
8. A battery cell, characterized in that: It includes a first pole piece, a second pole piece and an isolation membrane; the first pole piece, the isolation membrane and the second pole piece are stacked in sequence and wound to form a winding body; the first pole piece and / or the second pole piece is the battery cell pole piece structure as described in any one of claims 1 to 7 above.
9. The battery cell according to claim 8, characterized in that: The winding body includes a head section, a middle section and a tail section which are connected in sequence; the first connecting member and the second connecting member are both arranged on the head section.
10. A battery, characterized in that: Comprising the battery cell according to claim 8 or 9.