Battery cell isolating membrane structure and battery cell
By using a second coating layer in the battery cell isolation film structure that is located in abutment with the base material, the problem of slow infiltration of lithium-ion battery electrolyte is solved, and rapid infiltration of electrolyte and improved battery performance are achieved.
Patent Information
- Application Number
- CN202420261574.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-02
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-02-02
AI Technical Summary
The prior art has slower in electrolyte in lithium-ion batteries, especially in tightly bonded cores, resulting in low production efficiency.
A battery cell isolation film structure is adopted, including a substrate, a first coating layer and a second coating layer. The second coating layer and the substrate are arranged in abutment at the boundary of the substrate, so that it can be decomposed under certain conditions and shortened the electrolyte infiltration path.
By fully contacting and decomposing the second coating layer with the electrolyte, the electrolyte can quickly fill the pores between the electrode sheet and the isolation film structure, improve the battery wetting ability and the electrolyte wetting speed, and enhance the conductivity and structural stability.
Smart Images
Figure CN222673238U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of battery cores, and in particular relates to a battery core isolation film structure and a battery core. Background Art
[0002] Lithium-ion batteries are mainly composed of positive electrode, negative electrode, electrolyte and separator. + It can be reversibly deintercalated between the positive and negative electrodes through the separator; and the electrolyte is Li + In order to ensure the performance of the battery, the electrolyte must completely infiltrate the positive electrode, negative electrode and separator to form a Li + Conductive path.
[0003] Usually, after the electrolyte is injected from the top of the battery, most of the electrolyte flows downward and gathers at the bottom of the battery, and then penetrates into the pores of the diaphragm and the positive and negative electrode sheets through capillary pressure. The positive and negative electrode sheets and the diaphragm are fully infiltrated by extending the static time after the injection. However, this method takes a long time, and for the tightly bonded winding core, the static time will be greatly extended, thereby reducing production efficiency. Utility Model Content
[0004] The utility model aims to provide a cell isolation membrane structure to improve the electrolyte infiltration speed 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 battery cell isolation film structure comprises a substrate, a first coating layer and a second coating layer; the first coating layer and the second coating layer are coated on at least one surface of the substrate; and at least one of the first coating layer and the second coating layer is disposed in contact with a boundary of the substrate.
[0007] Preferably: a boundary abutment and / or a gap is provided between the first coating layer and the second coating layer.
[0008] Preferably, the relationship between the thickness H1 of the first coating layer and the thickness H2 of the second coating layer is: H1-H2=A, wherein A=0 mm to 0.08 mm.
[0009] Preferably, the number of the first coating layers is at least two, the number of the second coating layers is at least one, and the second coating layer is disposed between two adjacent first coating layers.
[0010] Preferably: the first coating layer is arranged in a honeycomb shape.
[0011] Preferably: the second coating layer includes at least one first folded edge and at least one second folded edge; and the first folded edge and the second folded edge are arranged to be staggered and connected to each other; the first folded edge abuts against the first coating layer; and the second folded edge abuts against the first coating layer.
[0012] Preferably: the second coating layer includes at least one arcuate convex portion and at least one arcuate concave portion; and the arcuate convex portions and the arcuate concave portions are arranged in an interlaced manner; the arcuate convex portion abuts against the first coating layer; and the arcuate concave portion abuts against the first coating layer.
[0013] Preferably: the first coating layer is a gel material.
[0014] Preferably, the second coating layer is one of Fe3O4 nano-microspheres, a vanadium oxide second coating layer, an acrylamide material, a methacrylic acid material and an acrylonitrile material.
[0015] The utility model also discloses a battery core, comprising an anode sheet, a cathode sheet and an isolation membrane arranged between the anode sheet and the cathode sheet; the isolation membrane is the battery core isolation membrane structure described above.
[0016] The beneficial effect of the utility model lies in that the technical solution can achieve full contact between the second coating layer and the electrolyte by adopting the second coating layer abutting against the upper boundary of the substrate, so that the second coating layer can be decomposed under certain conditions, thereby shortening the electrolyte infiltration path, so that the electrolyte can quickly fill the pores between the pole piece and the battery cell isolation membrane structure; thereby improving the battery infiltration ability, and increasing the electrolyte infiltration speed of the isolation membrane structure during the use of the battery cell, improving its conductive performance and facilitating the structural stability; in addition, by simultaneously arranging the first coating layer and the second coating layer on the surface of the substrate, the coating area of the first coating layer can be effectively reduced, thereby effectively saving the use of the first coating layer, and can also ensure the stability of assembly, thereby improving the safety and stability of use. 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 cell isolation membrane structure according to an embodiment of the utility model;
[0019] Figure 2 This is a schematic structural diagram of a cell isolation membrane structure according to an embodiment of the utility model;
[0020] Figure 3 A cross-sectional view of the AA section of the cell isolation membrane structure according to an embodiment of the utility model;
[0021] Figure 4 This is a structural schematic diagram of a cell isolation membrane structure of another embodiment of the utility model;
[0022] Figure 5 A schematic structural diagram of a cell isolation membrane structure according to another embodiment of the utility model;
[0023] Figure 6 It is a schematic structural diagram of a battery cell according to an embodiment of the utility model.
[0024] In the figure: 1-substrate; 2-first coating layer; 3-second coating layer; 301-first folded edge; 302-second folded edge; 303-arc-shaped convex portion; 304-arc-shaped concave portion; 4-gap; 100-isolating film; 200-anode sheet; 300-cathode sheet. 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 cell isolation membrane structure, the cell and the battery to describe the associated objects, indicating that three relationships may exist. For example, A and / or B can represent: 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 cell isolation membrane structure, a 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 As shown, in one embodiment of the utility model, the cell isolation film structure includes a substrate 1, a first coating layer 2 and a second coating layer 3; the first coating layer 2 and the second coating layer 3 are coated on at least one surface of the substrate 1; and at least one of the first coating layer 2 and the second coating layer 3 is disposed in contact with the boundary of the substrate 1. The boundary of the substrate 1 is any one, two, three or all of the boundary ends of the surface of the substrate 1 in the four directions of left, right, front and back.
[0034] The technical solution of the utility model can achieve full contact between the second coating layer and the electrolyte by adopting a second coating layer that is arranged in contact with the upper boundary of the substrate, so that the second coating layer can be decomposed under certain conditions, thereby shortening the electrolyte infiltration path, so that the electrolyte can quickly fill the pores between the pole piece and the battery cell isolation membrane structure; thereby improving the battery infiltration ability, and increasing the electrolyte infiltration speed of the isolation membrane structure during the use of the battery cell, improving its conductive performance and facilitating the structural stability; in addition, by simultaneously arranging the first coating layer and the second coating layer on the surface of the substrate 1, the coating area of the first coating layer can be effectively reduced, thereby effectively saving the use of the first coating layer, and can also ensure the stability of the assembly, thereby improving the safety and stability of use.
[0035] In some embodiments, the first coating layer 2 is a gel material; wherein the gel material may be composed of 10% to 20% gel dry powder, 2% to 6% adhesive, 0.3% to 1% dispersant and 73% to 87.7% deionized water, wherein the adhesive is one of polyurethane, polyacrylic acid and polyimide adhesives. Alternatively, the gel material may be one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile and polymethyl methacrylate.
[0036] In some embodiments, the second coating layer 3 may be one of Fe3O4 nano-microspheres, a vanadium oxide second coating layer, an acrylamide material, a methacrylic acid material and an acrylonitrile material.
[0037] Specifically, in some embodiments, Figure 1As shown, a boundary abutment and / or a gap is provided between the first coating layer 2 and the second coating layer 3. That is to say, when the substrate 1 is in the first state, one side end of the second coating layer 3 abuts against the side end of the first coating layer 2. Among them, the first state is the state in which the first coating layer 2 and the second coating layer 3 are respectively assembled and installed on the surface of the substrate 1, or the state in which the anode sheet and the cathode sheet of the battery cell isolation membrane structure are respectively assembled. This method can effectively ensure the compactness of the assembly between the anode sheet, the cathode sheet and the battery cell isolation membrane structure, reduce the generation of excessive gaps, and thus effectively reduce the thickness of the battery cell. When the substrate 1 is in the second state, the first side end of the second coating layer 3 abuts against the side end of the first coating layer 2, and a gap 4 is provided between the second side end of the second coating layer 3 and the first coating layer 2. Among them, the second state is the state in which the battery cell isolation membrane structure is in contact with the electrolyte and the temperature and other conditions reach the preset value. That is, as the battery cell is heated to a certain preset temperature, the second coating layer 3 decomposes and its core material electrolyte is released, thereby shortening the electrolyte infiltration path and improving the battery infiltration ability, so that the generated gas is discharged through the gap 4, and then the gap is used as an electrolyte flow channel so that the electrolyte can quickly flow back during the battery cell charging and discharging process, thereby improving the battery cell performance. In addition, the gap can also improve the stress concentration caused by the expansion of the pole piece during the cycle of the battery cell, thereby improving the cycle performance.
[0038] Among them, Figure 3 As shown, the first coating layer 2 is relatively arranged on the upper and lower surfaces of the substrate 1; the second coating layer 3 is relatively arranged on the upper and lower surfaces of the substrate 1. Among them, (not shown in the figure) the first coating layer 2 is arranged on the upper and lower surfaces of the substrate 1; the second coating layer 3 is arranged on the upper and lower surfaces of the substrate 1; and on the different two side surfaces of the substrate 1, one of the first coating layers 2 and one of the second coating layers 3 are arranged oppositely; that is, the first coating layers 2 on different sides and the second coating layers 3 on different sides are arranged in an up-down staggered manner (the first coating layer 2 on the upper surface faces the second coating layer 3 on the lower surface).
[0039] Specifically, in some embodiments, Figure 3 As shown, the relationship between the thickness H1 of the first coating layer 2 and the thickness H2 of the second coating layer 3 is: H1-H2=A, where A=0mm~0.08mm. Preferably, A=0. That is to say, the first coating layer 2 and the second coating layer 3 are on the substrate 1 and are on the same horizontal plane; thereby ensuring the assembly flatness between the cell isolation membrane structure and the anode sheet and the cathode sheet, respectively, and thus effectively reducing the overall thickness of the cell.
[0040] Specifically, in some embodiments, Figure 1 and 2As shown, the number of the first coating layers 2 is at least two, the number of the second coating layers 3 is at least one; and the second coating layer 3 is disposed between two adjacent first coating layers 2. That is, the second coating layer 3 separates the first coating layers 2, and when the electrolyte contacts the second coating layer 3 and decomposes the second coating layer 3, the gap is realized as a gas channel, thereby improving the stress concentration caused by the expansion of the pole piece during the cycle of the battery cell and improving the cycle performance.
[0041] Specifically, in one embodiment, Figure 1 and 2 As shown, the first coating layers 2 are arranged side by side at equal distances or in a honeycomb shape; the second coating layer 3 is arranged between two adjacent first coating layers 2. This structure can achieve uniform distribution of the coverage area of the first coating layer 2, so that the pole pieces fit closely together, ensuring stable performance of the battery.
[0042] Specifically, in other embodiments, Figure 4 As shown, the second coating layer 3 includes at least one first fold 301 and at least one second fold 302; and the first fold 301 and the second fold 302 are arranged in a staggered manner; the first fold 301 abuts against the first coating layer 2; the second fold 302 abuts against the first coating layer 2. In other words, the first fold 301 and the second fold 302 form a V-shaped or W-shaped structure. Further, as Figure 3 As shown, the width D of the first folded edge 301 and / or the second folded edge 302 has a value range of: 1mm≤D≤10mm; further, D can be any value between 1 and 10mm, such as 1mm, 2mm, 5mm, 6.5mm, 10mm, etc. This structure can effectively ensure that the gas can be quickly discharged from the gap 4 through the second coating layer 3 of appropriate width.
[0043] Specifically, in some other embodiments, Figure 5 As shown, the second coating layer 3 includes at least one arc-shaped convex portion 303 and at least one arc-shaped concave portion 304; and the arc-shaped convex portion 303 and the arc-shaped concave portion 304 are arranged in an interlaced manner; the arc-shaped convex portion 303 abuts against the first coating layer 2; and the arc-shaped concave portion 304 abuts against the first coating layer 2. In other words, the second coating layer 3 is connected in a wavy manner with a horizontal interval, which is conducive to the retention of electrolyte in the internal area of the battery cell during the charging and discharging process, so as to avoid the expansion of the pole piece affecting the reflux of the electrolyte and causing the electrolyte to move to the two ends of the battery cell; thereby improving the flow uniformity of the electrolyte and improving the performance of the battery cell.
[0044] The utility model also provides a battery cell, such as Figure 6As shown, the battery cell includes an anode sheet 200, a cathode sheet 300 and an isolation membrane 100 arranged between the anode sheet 200 and the cathode sheet 300; the isolation membrane 100 is the above-mentioned battery cell isolation membrane structure, and the specific structure of the battery cell isolation membrane structure refers to the above-mentioned embodiment. Since this subject two 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.
[0045] The anode sheet 200 includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector; the positive electrode current collector includes a positive electrode coating area and a positive electrode tab 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 tab is not coated with the positive electrode active material layer. The cathode sheet 300 includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area, the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode tab is not coated with a negative electrode active material layer.
[0046] 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.
[0047] 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 cell isolation membrane structure, characterized in that: It comprises a substrate, a first coating layer and a second coating layer; the first coating layer and the second coating layer are coated on at least one surface of the substrate; and at least one of the first coating layer and the second coating layer is disposed in contact with the boundary of the substrate.
2. The cell isolation membrane structure according to claim 1, characterized in that: A boundary abutment and / or a gap is provided between the first coating layer and the second coating layer.
3. The cell isolation membrane structure according to claim 1, characterized in that: The relationship between the thickness H1 of the first coating layer and the thickness H2 of the second coating layer is: H1-H2=A, wherein A=0 mm to 0.08 mm.
4. The cell isolation membrane structure according to any one of claims 1 to 3, characterized in that: The number of the first coating layers is at least two, the number of the second coating layers is at least one; and the second coating layer is disposed between two adjacent first coating layers.
5. The cell isolation membrane structure according to claim 4, characterized in that: The first coating layer is arranged in a honeycomb shape.
6. The cell isolation membrane structure according to claim 4, characterized in that: The second coating layer includes at least one first folded edge and at least one second folded edge; the first folded edge and the second folded edge are arranged to be staggered and connected to each other; the first folded edge abuts against the first coating layer; and the second folded edge abuts against the first coating layer.
7. The cell isolation membrane structure according to claim 4, characterized in that: The second coating layer includes at least one arcuate convex portion and at least one arcuate concave portion; and the arcuate convex portions and the arcuate concave portions are arranged in an interlaced manner; the arcuate convex portion abuts against the first coating layer; and the arcuate concave portion abuts against the first coating layer.
8. The cell isolation membrane structure according to claim 1, characterized in that: The first coating layer is a gel material.
9. The cell isolation membrane structure according to claim 1, characterized in that: The second coating layer is one of Fe3O4 nano-microspheres, a vanadium oxide second coating layer, an acrylamide material, a methacrylic acid material and an acrylonitrile material.
10. A battery cell, characterized in that: It comprises an anode sheet, a cathode sheet and an isolation membrane arranged between the anode sheet and the cathode sheet; the isolation membrane is the battery cell isolation membrane structure as described in any one of claims 1 to 8 above.