Battery cell diaphragm structure, battery cell and secondary battery

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a battery cell diaphragm structure, a battery cell and a secondary battery. The battery cell diaphragm structure comprises a base material, a connecting coating, a heat-resistant coating and a bonding layer, the heat-resistant coating is connected to the surface of one side of the base material; the bonding layer is connected to the surface of one side, far away from the base material, of the heat-resistant coating; and the connecting coating is connected to the surface of the other side, far away from the heat-resistant coating, of the base material. According to the utility model, targeted assembly between the diaphragm structure and the positive and negative pole pieces can be realized when the diaphragm structure is used, so that the overall structural stability and the use safety and stability are improved.

Description

Technical Field

[0001] This utility model belongs to the field of battery technology, and in particular relates to a cell separator structure, a cell, and a secondary battery. Background Technology

[0002] Lithium-ion batteries have been widely used in the 3C (computer, communication, and consumer electronics) field, electric vehicles, and energy storage due to their advantages such as high energy density, high voltage, long cycle life, high-rate discharge, low self-discharge, and environmental friendliness. Lithium-ion battery technology continues to advance, with high energy density being the main development direction. Generally, a lithium-ion battery consists of a positive electrode, a negative electrode, and a battery separator between them. The battery separator is a crucial component of the battery, directly impacting battery safety and cost. Its main functions are to isolate the positive and negative electrodes, preventing electrons from freely passing through while allowing ions in the electrolyte to freely pass between them.

[0003] However, some existing battery separators offer low protection for the first or second electrode, making them prone to deformation and affecting rate and fast charging performance; thus greatly reducing safety and stability in use. Utility Model Content

[0004] The purpose of this invention is to provide a battery cell separator structure that addresses the shortcomings of existing technologies and solves the problem of poor stability in the use of existing technologies.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A battery cell separator structure includes a substrate, a connecting coating, a heat-resistant coating, and an adhesive layer; the heat-resistant coating is connected to one side surface of the substrate; the adhesive layer is connected to the side surface of the heat-resistant coating away from the substrate; and the connecting coating is connected to the other side surface of the substrate away from the heat-resistant coating.

[0007] Preferably, the thickness h1 of the connecting coating satisfies: 0.5μm≤h1≤10μm.

[0008] Preferably, the thickness h2 of the heat-resistant coating satisfies: 0.5μm≤h2≤10μm.

[0009] Preferably, the thickness h3 of the adhesive layer satisfies: 0.5μm≤h3≤10μm.

[0010] Preferably, the projection of the adhesive layer toward the substrate covers the heat-resistant coating.

[0011] Preferably, the bonding coating is made of polymethyl methacrylate or polycarbonate.

[0012] Preferably, the heat-resistant coating is made of ceramic material or nano-alumina material.

[0013] Preferably, the adhesive layer is made of polyvinylidene fluoride, perfluoroethylene propylene, or polyether ketone ketone.

[0014] This utility model also discloses a battery cell, including a second electrode and a first electrode, and the aforementioned battery cell separator structure disposed between the second electrode and the first electrode, wherein the second electrode is connected to the adhesive layer on the side surface away from the substrate; and the first electrode is connected to the connecting coating on the side surface away from the substrate.

[0015] This utility model also discloses a secondary battery, including the aforementioned battery cell.

[0016] The beneficial effects of this utility model are as follows: This technical solution uses a connecting coating and an adhesive layer mounted on two different side surfaces of the substrate, and the connecting coating and adhesive layer are respectively used for assembly with the positive and negative electrode sheets, so as to achieve targeted assembly between the diaphragm structure and the positive and negative electrode sheets during use, thereby improving the overall structural stability and the safety and stability of use; Furthermore, the high-temperature resistance of the heat-resistant coating avoids misalignment due to thermal shrinkage of the diaphragm, and also prevents burrs of the current collector foil from penetrating the diaphragm structure; thus, it is beneficial to achieve gap creation between the diaphragm structure and the positive and negative electrode sheets, and improve the immersion performance of the electrolyte. Attached Figure Description

[0017] The following will refer to the appendix. Figures 1-4 This section describes the features, advantages, and technical effects of exemplary embodiments of the present invention.

[0018] Figure 1 This is a schematic diagram of the battery cell separator structure according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the battery cell separator structure according to one embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the cell separator structure according to another embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present invention.

[0022] In the figure: 1-substrate; 2-connecting coating; 3-heat resistant coating; 4-adhesive layer; 500-first electrode; 600-second electrode. Detailed Implementation

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0024] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0025] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0026] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or multiple situations existing alone. In addition, the character " / " in this document generally indicates that the related objects before and after are in an "or" relationship.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] The following is in conjunction with the appendix Figures 1-4 The present invention will be described in further detail, but this is not intended to limit the scope of the present invention.

[0029] like Figure 1As shown, in one embodiment of this utility model, the battery cell separator structure includes a substrate 1, a connecting coating 2, a heat-resistant coating 3, and an adhesive layer 4; the heat-resistant coating 3 is connected to one side surface of the substrate 1; the adhesive layer 4 is connected to the side surface of the heat-resistant coating 3 away from the substrate 1; and the connecting coating 2 is connected to the other side surface of the substrate 1 away from the heat-resistant coating 3.

[0030] The technical solution of this utility model employs a connecting coating and an adhesive layer mounted on two different side surfaces of a substrate. These connecting and adhesive layers are used for assembly with the positive and negative electrode sheets, respectively, to achieve targeted assembly between the diaphragm structure and the positive and negative electrode sheets during use. This improves the overall structural stability, as well as the safety and stability of its use. Furthermore, the high-temperature resistance of the heat-resistant coating prevents misalignment due to thermal shrinkage of the diaphragm and also prevents burrs from the current collector foil from penetrating the diaphragm structure. This facilitates the creation of gaps between the diaphragm structure and the positive and negative electrode sheets, and improves the electrolyte immersion performance.

[0031] The substrate 1 can be PP (polypropylene) or PE (polyethylene), etc.

[0032] Specifically, in some embodiments, the connecting coating 2 is selected from polymethyl methacrylate (PMMA) or polycarbonate (PC), etc. The connecting coating 2 is preferably polymethyl methacrylate (PMMA). This structure achieves good optical performance, weather resistance, and processability of the diaphragm structure through the PMMA material, thereby achieving more stable assembly performance with the first electrode and ensuring overall structural stability. The connecting coating 2 can be applied by gravure printing, spraying, or impregnation.

[0033] Specifically, in some embodiments, the heat-resistant coating 3 is selected from ceramic materials or nano-alumina materials. Ceramic materials are preferred. The ceramic material can be one of zirconium dioxide, silicon carbide, silicon nitride, boehmite, silicon dioxide, titanium dioxide, magnesium dioxide, barium sulfate, zirconium oxide, and calcium oxide, to improve the high-temperature resistance of the diaphragm structure.

[0034] Specifically, in some embodiments, the adhesive layer 4 is selected from polyvinylidene fluoride (PVDF), perfluoroethylene propylene (FEP), or polyether ketone ketone (PEEK). PVDF is preferred. This structure, through the dotted PVDF, can achieve stable assembly between the adhesive layer and the second electrode, and can also prevent deformation of the second electrode.

[0035] Specifically, in some implementations, such as Figure 1 and 2As shown, the thickness h1 of the connecting coating 2 satisfies: 0.5μm ≤ h1 ≤ 10μm. For example, it can be 0.1μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm. This structure, with a suitable thickness h1 of the connecting coating 2, ensures that the diaphragm structure is appropriately sized, thereby ensuring the orderly realization of the cell's performance.

[0036] Specifically, in some implementations, such as Figure 1 and 2 As shown, the thickness h2 of the heat-resistant coating 3 satisfies: 0.5μm ≤ h2 ≤ 10μm. The thickness h3 of the adhesive layer 4 satisfies: 0.5μm ≤ h3 ≤ 10μm. For example, h2 can be 0.1μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm. Similarly, h3 can be 0.1μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, or 10μm. This structure, with appropriately sized heat-resistant coating 3 thickness h2 and adhesive layer 4 thickness h3, ensures that the diaphragm structure is appropriately sized, thereby ensuring the orderly realization of the cell's performance.

[0037] Specifically, in some implementations, such as Figure 1 and 2 As shown, the relationship between the thickness h1 of the connecting coating 2, the thickness h2 of the heat-resistant coating 3, and the thickness h3 of the adhesive layer 4 satisfies: h1 = h2 + h3. This structure, through the symmetrical arrangement of the connecting coating 2, the heat-resistant coating 3, and the adhesive layer 4, ensures that the dimensions of the diaphragm structure are appropriate, thereby ensuring the orderly realization of the cell's performance.

[0038] Specifically, in some implementations, such as Figure 1 and 3 As shown, the projection of the adhesive layer 4 toward the substrate 1 covers the heat-resistant coating 3. That is, the adhesive layer 4 includes a connecting side and a covering surface; the covering surface covers and connects to the surface of the heat-resistant coating 3 away from the substrate 1; one end of the connecting side is connected to the substrate 1, and the other end of the connecting side is connected to the covering surface; the inner surface of the connecting side surrounds and abuts against the circumferential surface of the heat-resistant coating 3. This structure, through its surrounding and covering assembly, avoids misalignment caused by thermal shrinkage and also prevents burrs on the manifold; thereby improving safety and stability in use.

[0039] This utility model also proposes a battery cell, which includes a second electrode 600 and a first electrode 500, and a battery cell separator structure disposed between the second electrode 600 and the first electrode 500. The second electrode 600 is connected to the adhesive layer 4 on the surface away from the substrate 1; the first electrode 500 is connected to the connecting coating 2 on the surface away from the substrate 1. The specific structure of the battery cell separator structure is as described in the above embodiments. Since this secondary battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The second electrode 600 is a positive electrode; the first electrode 500 is a negative electrode.

[0040] The second electrode 600 includes a positive current collector and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector. The positive current collector includes a positive coating area and a positive electrode tab connected to the positive coating area. The positive coating area is coated with the positive active material layer, while the positive electrode tab is not coated with the positive active material layer. The material of the positive current collector can be aluminum, and the positive active material layer includes positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The first electrode 500 includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector. The negative current collector includes a negative coating area and a negative electrode tab connected to the negative coating area. The negative coating area is coated with the negative active material layer, while the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The substrate 1 can be PP (polypropylene) or PE (polyethylene), etc.

[0041] This utility model also proposes a secondary battery, which includes a battery cell. The specific structure of the battery cell is as described in the above embodiments. Since this secondary battery adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0042] A rechargeable battery, also known as a secondary battery or accumulator battery, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. Utilizing the reversibility of chemical reactions, a new battery can be constructed; that is, after a chemical reaction converts into electrical energy, the electrical energy can be used to repair the chemical system, and then the chemical reaction can be converted back into electrical energy. Therefore, it is called a secondary battery (rechargeable battery). The main types of rechargeable batteries on the market include nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid (or lead-acid) batteries, lithium-ion batteries, and polymer lithium-ion batteries.

[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0044] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this utility model are within the protection scope of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. An electrochemical cell separator structure, characterized by: The application relates to a structure of an electrode core diaphragm, which comprises a base material, a connecting coating layer, a heat-resistant coating layer and a bonding layer; the heat-resistant coating layer is connected to one side surface of the base material; the bonding layer is connected to the side surface of the heat-resistant coating layer away from the base material; and the connecting coating layer is connected to the other side surface of the base material away from the heat-resistant coating layer.

2. The cell separator structure of claim 1, wherein: The thickness h1 of the connecting coating layer satisfies 0.5 mu m<=h1<=10 mu m.

3. The cell separator structure according to claim 1 or 2, characterized by: The thickness h2 of the heat-resistant coating layer satisfies 0.5 mu m<=h2<=10 mu m.

4. The cell separator structure according to claim 1 or 2, characterized by: The thickness h3 of the bonding layer satisfies 0.5 mu m<=h3<=10 mu m.

5. The cell separator structure of claim 1, wherein: The projection of the bonding layer towards the base material covers the heat-resistant coating layer.

6. The cell separator structure of claim 1, wherein: The connecting coating layer is made of polymethyl methacrylate or polycarbonate.

7. The cell separator structure of claim 1, wherein: The heat-resistant coating layer is made of ceramic material or nano-aluminum oxide material.

8. The cell separator structure of claim 1, wherein: The bonding layer is made of polyvinylidene fluoride or polyfluoroethylene propylene or polyether ketone ketone.

9. An electric cell characterized by: The application further relates to an electrode core, which comprises a second pole piece, a first pole piece and the electrode core diaphragm structure according to any one of claims 1 to 8, and the second pole piece is connected to the side surface of the bonding layer away from the base material; and the first pole piece is connected to the side surface of the connecting coating layer away from the base material.

10. A secondary battery characterized by comprising: The application further relates to an electrode core, which comprises the electrode core according to claim 9.

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