Pole piece structure, battery cell and battery
By bending the projection in the electrode sheet structure, an empty foil area is formed, which solves the problems of concentrated stress and large volume occupancy at the electrode weld in traditional batteries, and improves the energy density and structural stability of the battery cell.
Patent Information
- Application Number
- CN202420493436.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-14
- Publication Date
- 2025-02-14
- Estimated Expiration
- 2034-03-14
AI Technical Summary
There is a stress concentration point at the welding of the electrode ear and the electrode sheet in a traditional battery, which can easily damage the current collector material area and occupy a large volume, reducing the energy density of the battery.
The projection is bent in the pole sheet structure to form a first empty foil area and a second empty foil area to reduce damage to the current collector during welding and increase the coating area.
It effectively improves the energy density and structural stability of the battery cell, and reduces damage to the current collector during welding.
Smart Images
Figure CN222483399U_ABST
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 electronic products develop towards miniaturization and multifunctionality, the energy density requirements for batteries are getting higher and higher, which requires the battery cells to provide more capacity in the same space. In the traditional wound structure of secondary batteries, blank current collectors are provided at the beginning of the positive and negative electrode sheets. One end of the positive and negative electrode tabs is directly welded to the blank current collectors on the positive and negative electrode sheets, and the other end protrudes about 10mm from the packaging bag.
[0003] However, in the existing technical solutions, the welding point between the pole tab and the cathode and anode sheets is in the longitudinal direction of the electrode sheets, and the A side and the B side of the welding point are not coated with slurry; and the position where the pole tab is installed becomes a stress concentration point during welding, which is easy to damage the material area of the collector, thereby affecting the stability of the structure; at the same time, the position where the pole tab is installed occupies a large volume, which reduces the energy density of the battery to a certain extent. Utility Model Content
[0004] The purpose of the utility model is to provide a pole piece structure, a battery cell and a battery to solve any of the above technical problems in view of the deficiencies of the prior art.
[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 first coating and a second coating; the current collector comprises a main body and a protrusion connected to the main body; and the main body has a first surface and a second surface arranged opposite to each other; the first coating is coated on the first surface; the second coating is coated on the second surface; and a first empty foil area is provided on the first surface away from the first coating; a second empty foil area is provided on the second surface away from the second coating; and the protrusion is bent toward the first empty foil area or the second empty foil area.
[0007] Preferably, a projected area of the first empty foil area toward the current collector is smaller than a projected area of the second empty foil area toward the current collector.
[0008] Preferably, the protruding portion is bent toward the second empty foil area.
[0009] Preferably: the pole piece structure also includes a pole ear; the pole ear is connected to a side surface of the protrusion close to the first empty foil area; and when the protrusion is bent and arranged in the second empty foil area, the pole ear and the main body are relatively arranged on both sides of the protrusion, and the pole ear is arranged in the second empty foil area.
[0010] Preferably: the tab comprises a connecting section and a bending section which are connected to each other obliquely; and the connecting section is connected to the protruding portion.
[0011] Preferably, the bending section is bent toward the protruding portion.
[0012] Preferably, when the protrusion is bent and arranged in the second empty foil area, the relationship between the thickness L1 of the second coating layer, the thickness L2 of the protrusion and the thickness L3 of the tab satisfies: L1<L2+L3.
[0013] Preferably: the pole piece structure further comprises an adhesive component; when the protruding portion is bent and arranged in the second empty foil area, the protruding portion and the main body are respectively connected to the adhesive component.
[0014] The utility model also discloses a battery cell, comprising a first pole piece, a second pole piece and an isolation membrane arranged between the first pole piece and the second pole piece; and the polarities of the first pole piece and the second pole piece are opposite; the first pole piece and / or the second pole piece is the pole piece structure described above.
[0015] The utility model also discloses a battery, comprising the battery core described above.
[0016] The beneficial effect of the utility model lies in that the technical solution adopts a protrusion that is bent toward the first empty foil area or the second empty foil area when in use, thereby effectively reducing the first empty foil area or the second empty foil area to avoid damage to the material area of the collector when assembling the pole ear by laser or ultrasonic welding, and avoiding the position of the assembled pole ear from becoming a stress concentration point; thereby effectively increasing the coating area, and is beneficial to improving the energy density of the battery cell and improving the stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following will refer to the attached Figures 1 to 5 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 before bending operation according to an embodiment of the utility model;
[0019] Figure 2 A top view of a pole piece structure according to an embodiment of the utility model;
[0020] Figure 3 This is a schematic structural diagram of a pole piece structure before bending operation according to an embodiment of the utility model;
[0021] Figure 4 This is a schematic structural diagram of a pole piece structure of an embodiment of the utility model;
[0022] Figure 5 It is a partial enlarged view of the pole piece structure of one embodiment of the utility model.
[0023] In the figure: 1-current collector; 11-main body; 12-protrusion; 101-first empty foil area; 102-second empty foil area; 103-first surface; 104-second surface; 2-first coating; 3-second coating; 4-ear; 41-connecting section; 42-bending section; 5-adhesive component. DETAILED DESCRIPTION
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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).
[0029] 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.
[0030] 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.
[0031] The following is combined with Figure 1 to Figure 5 The utility model is further described in detail, but it is not intended to limit the utility model.
[0032] like Figure 1 and 2 As shown, in one embodiment of the utility model, the pole piece structure includes a current collector 1, a first coating 2 and a second coating 3; the current collector 1 includes a main body 11 and a protrusion 12 connected to the main body 11; and the main body 11 has a first surface 103 and a second surface 104 arranged opposite to each other; the first coating 2 is coated on the first surface 103; the second coating 3 is coated on the second surface 104; and a first empty foil area 101 is provided on the first surface 103 away from the first coating 2; a second empty foil area 102 is provided on the second surface 104 away from the second coating 3; the protrusion 12 is bent toward the first empty foil area 101 or the second empty foil area 102.
[0033] The technical solution of the utility model adopts a protrusion that is bent toward the first empty foil area or the second empty foil area when in use, thereby effectively reducing the first empty foil area or the second empty foil area to avoid damage to the material area of the collector when assembling the pole ear by laser or ultrasonic welding, and avoiding the position of the assembled pole ear from becoming a stress concentration point; thereby effectively increasing the coating area, and is beneficial to improving the energy density of the battery cell, and improving the stability of the structure.
[0034] Specifically, in some embodiments, Figure 1 and 3 As shown, the projection area of the first empty foil area 101 toward the current collector 1 is smaller than the projection area of the second empty foil area 102 toward the current collector 1; and the protrusion 12 is bent toward the second empty foil area 102. That is, the first coating 2 is a wide coating, and the second coating 3 is a narrow coating; and the protrusion 12 is bent toward the second empty foil area 102 of the narrow coating, so that the second empty foil area can be minimized to avoid damage to the material area of the current collector when assembling the pole ear by laser or ultrasonic welding, and the position of the assembled pole ear can be avoided from becoming a stress concentration point; thereby, the coating area can be effectively increased, and it is beneficial to improve the energy density of the battery cell and improve the stability of the structure.
[0035] Specifically, in some embodiments, Figure 1 and 3 As shown, the pole piece structure also includes a pole ear 4; the pole ear 4 is connected to a side surface of the protrusion 12 close to the first empty foil area 101; and when the protrusion 12 is in a bent state, the pole ear 4 and the main body 11 are relatively arranged on both sides of the protrusion 12, and the pole ear 4 is arranged in the second empty foil area 102. That is to say, the pole ear 4 is welded on the protrusion 12 on the same surface as the wide coating; after the pole ear 4 is welded to the protrusion 12, the protrusion 12 is bent and folded to the second empty foil area 102, and the pole ear 4 is coated on the protrusion 12, which can effectively increase the coating area and improve the energy density of the battery cell, and can also avoid damage to the material area by laser or ultrasonic welding.
[0036] Specifically, in some embodiments, Figure 3 As shown, the tab 4 includes a connecting section 41 and a bending section 42 connected to each other obliquely; and the connecting section 41 is connected to the protruding portion 12. In some embodiments, as Figure 3 and 4As shown, the bending section 42 is configured to be able to be bent toward the protrusion 12. That is, the electrode tab 4 is welded on the protrusion 12 on the same surface of the wide coating; then the current collector 1 and the electrode tab 4 are folded from a convex shape to a rectangle by folding, so that the second empty foil area can be reduced to avoid damage to the material area of the current collector when the electrode tab is assembled by laser or ultrasonic welding, and the position where the electrode tab is assembled can be avoided from becoming a stress concentration point; thereby improving the stability of the structure, increasing the slurry coating area, and increasing the energy density of the battery cell.
[0037] Specifically, in some embodiments, Figure 4 As shown, when the protrusion 12 is bent and arranged in the second empty foil area 102, the relationship between the thickness L1 of the second coating 3, the thickness L2 of the protrusion 12 and the thickness L3 of the tab 4 satisfies: L1<L2+L3. Among them, the thickness of the connecting section 41 is equal to the thickness of the bending section 42. That is, by folding and bending the tab 4 upward, the normal use of the tab 4 can be guaranteed, thereby improving the energy density of the battery cell.
[0038] Specifically, in some embodiments, Figure 4 and 5 As shown, the electrode structure also includes a bonding component 5; when the protrusion 12 is bent and arranged in the second empty foil area 102, the protrusion 12 and the main body 11 are respectively connected to the bonding component 5. Among them, the bonding component 5 is an adhesive. That is, the pole ear 4 is welded to the protrusion 12, and the welding surface is located on the wide coating surface; then the welded whole is folded downward toward the second empty foil area 102, so that the protrusion 12 and the main body 11 are bonded; finally, the pole ear 4 is folded upward so that the pole ear 4 can be kept at the same horizontal plane as the second coating 3 on the main body 11.
[0039] The utility model also proposes a battery cell, which includes a first pole piece, a second pole piece and an isolation membrane arranged between the first pole piece and the second pole piece; and the first pole piece and the second pole piece have opposite polarities; the first pole piece and / or the second pole piece are the pole piece structure described above. The specific structure of the pole piece structure refers to the above embodiment. Since the 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 repeated here. Among them, the first pole piece is an anode piece, and the second pole piece is a cathode piece; or, the first pole piece is a cathode piece, and the second pole piece is an anode piece. The material of the isolation membrane can be PP (polypropylene) or PE (polyethylene), etc.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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 includes a current collector, a first coating and a second coating; the current collector includes a main body and a protrusion connected to the main body; and the main body has a first surface and a second surface arranged opposite to each other; the first coating is coated on the first surface; the second coating is coated on the second surface; and a first empty foil area is provided on the first surface away from the first coating; a second empty foil area is provided on the second surface away from the second coating; the protrusion is bent toward the first empty foil area or the second empty foil area.
2. The pole piece structure according to claim 1, characterized in that: A projected area of the first empty foil region toward the current collector is smaller than a projected area of the second empty foil region toward the current collector.
3. The pole piece structure according to claim 1 or 2, characterized in that: The protruding portion is bent toward the second empty foil area.
4. The pole piece structure according to claim 1 or 2, characterized in that: The pole piece structure also includes a pole ear; the pole ear is connected to a side surface of the protrusion close to the first empty foil area; and when the protrusion is bent and arranged in the second empty foil area, the pole ear and the main body are relatively arranged on both sides of the protrusion, and the pole ear is arranged in the second empty foil area.
5. The pole piece structure according to claim 4, characterized in that: The pole ear comprises a connecting section and a bending section which are connected to each other obliquely; and the connecting section is connected to the protruding portion.
6. The pole piece structure according to claim 5, characterized in that: The bending section is bent toward the protruding portion.
7. The pole piece structure according to claim 6, characterized in that: When the protrusion is bent and disposed in the second empty foil area, the relationship between the thickness L1 of the second coating layer, the thickness L2 of the protrusion and the thickness L3 of the tab satisfies: L1<L2+L3.
8. The pole piece structure according to claim 1 or 2, characterized in that: The pole piece structure further comprises an adhesive component; when the protruding portion is bent and arranged in the second empty foil area, the protruding portion and the main body are respectively connected to the adhesive component.
9. A battery cell, characterized in that: It includes a first pole piece, a second pole piece, and an isolation membrane arranged between the first pole piece and the second pole piece; and the polarities of the first pole piece and the second pole piece are opposite; the first pole piece and / or the second pole piece are the pole piece structures described in claims 1 to 8 above.
10. A battery, characterized in that: The battery cell comprises the battery cell as claimed in claim 9.