Pole piece assembly, roll core and battery

Abstract

This utility model relates to an electrode assembly, a winding core, and a battery. The electrode assembly includes an electrode and an insulating tape. The electrode is either a negative electrode or a positive electrode. The insulating tape is located at the end of the electrode along its length and extends along the length of the electrode. After the electrode assembly is wound up, the insulating tape can be wound into a support column, and the electrode is wound around the outer periphery of the support column. This electrode assembly eliminates the need for a central tube inside the winding core, avoiding the problem of electrode collapse in the central area of ​​the winding core. The manufacturing process is simple, and it is beneficial for improving the overall energy density of the battery.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, specifically to an electrode assembly, a winding core, and a battery. Background Technology

[0002] Cylindrical lithium-ion batteries are currently widely used in various fields such as energy storage, power supply, and electric vehicles. Cylindrical batteries are usually produced using a winding process. During the finished product manufacturing process, the pulling of the winding needles creates a central hole in the center of the core. During use, the electrode sheets in the central hole area are prone to collapse, which can lead to shortened battery life and safety issues.

[0003] In existing technologies, cylindrical batteries typically use a central tube structure supported inside the core along a central hole to alleviate the problem of electrode collapse in the central hole area. However, the presence of the central tube not only occupies internal space but also requires separate installation and positioning, making the battery manufacturing process more complex and costly, and hindering the improvement of the overall energy density of the battery. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, embodiments of this utility model propose an electrode assembly that eliminates the need for a central tube inside the core, thus avoiding the problem of electrode collapse in the central area of ​​the core. The manufacturing process is simple and it is beneficial to improve the energy density of the core.

[0006] An embodiment of this utility model also proposes a winding core.

[0007] An embodiment of this utility model also proposes a battery.

[0008] The electrode assembly of this utility model includes: an electrode, which is either a negative electrode or a positive electrode; and an insulating tape, which is disposed at the end of the electrode along the length direction of the electrode and extends along the length direction of the electrode. After the electrode assembly is wound up, the insulating tape can be wound into a support column, and the electrode is wound around the outer periphery of the support column.

[0009] According to the electrode assembly of the present invention, since the insulating tape is located at the end of the electrode along the length of the electrode, after the electrode assembly is wound up, the insulating tape can be wound into a support column, and the electrode is wound around the outer periphery of the support column. Thus, the electrode assembly of the present invention can eliminate the need for a central tube inside the core and avoid the problem of electrode collapse in the central area of ​​the core. The manufacturing process is simple and it is beneficial to improve the overall energy density of the battery.

[0010] In some embodiments, the insulating tape includes a connecting segment and an extension segment, one end of the connecting segment is connected to the electrode, and the other end of the connecting segment is connected to the extension segment. In a projection orthogonal to the thickness direction of the electrode, the projection of the connecting segment overlaps with the projection of the electrode.

[0011] In some embodiments, before the electrode assembly is wound up, the extension section has a dimension L1 along the length direction of the electrode, wherein 18mm≤L1≤30mm.

[0012] In some embodiments, before the electrode assembly is wound up, the dimension of the connecting segment along the length direction of the electrode is L2, wherein 4mm≤L2≤6mm.

[0013] In some embodiments, after the electrode assembly is wound, the extension section has a winding number of turns of T, where 3 ≤ T ≤ 5.

[0014] In some embodiments, there are two insulating strips, and at least a portion of the electrode is located between the two insulating strips.

[0015] In some embodiments, the insulating tape has perforated holes.

[0016] In some embodiments, there are multiple perforations, and the multiple perforations are arranged at intervals on the insulating strip.

[0017] In some embodiments, the total area of ​​the perforated holes is Q1, and the area of ​​the insulating tape is Q2, wherein Q1 / Q2 ≥ 0.3.

[0018] In some embodiments, one end of the support column protrudes beyond the electrode by a dimension H along its axial direction, where 0 < H ≤ 1 mm.

[0019] In some embodiments, the thickness of the insulating tape is M, wherein 20μm≤M≤50μm.

[0020] In some embodiments, the tensile strength of the insulating tape is ≥100MPa.

[0021] In some embodiments, the insulating tape is one of polyimide tape, polyethylene terephthalate tape, and ceramic-coated tape.

[0022] In some embodiments, the insulating tape is bonded to the electrode sheet.

[0023] In some embodiments, the electrode is a negative electrode, which includes a copper foil and a negative electrode layer, the negative electrode layer being coated on the copper foil, and the insulating tape being bonded to the negative electrode layer.

[0024] The core of another embodiment of the present invention includes the electrode assembly described in any one of the embodiments of the present invention.

[0025] According to the embodiment of the present invention, since the insulating tape is located at the end of the electrode along the length of the electrode, after the electrode assembly is wound up, the insulating tape can be wound into a support column, and the electrode is wound around the outer periphery of the support column. Therefore, the internal structure of the core of the embodiment of the present invention does not need to be provided with a central tube, and the problem of electrode collapse in the central area of ​​the core can be avoided. The manufacturing process is simple and it is beneficial to improve the overall energy density of the battery.

[0026] Another embodiment of the battery of this utility model includes the winding core described in the embodiment of this utility model.

[0027] According to the battery of the present invention, since the insulating tape is located at the end of the electrode along the length of the electrode, after the electrode assembly is wound up, the insulating tape can be wound into a support column, and the electrode is wound around the outer periphery of the support column. Thus, the battery of the present invention can eliminate the need to set a central tube inside the core, and can avoid the problem of electrode collapse in the central area of ​​the core. The manufacturing process is simple and it is beneficial to improve the overall energy density of the battery. Attached Figure Description

[0028] Figure 1 This is a front view of the electrode assembly before winding, according to an embodiment of this utility model.

[0029] Figure 2 This is a front view of two electrode assemblies connected together according to an embodiment of the present invention.

[0030] Figure 3 This is a top view of two electrode assemblies connected together according to an embodiment of the present invention.

[0031] Figure 4 This is a top view of the insulating strip of the electrode assembly according to an embodiment of the present invention.

[0032] Figure label:

[0033] 1. Electrode; 11. Negative electrode; 111. Copper foil; 112. Negative electrode layer;

[0034] 2. Insulating tape; 21. Connecting section; 22. Extension section; 23. Hole. Detailed Implementation

[0035] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0036] The following is a reference appendix. Figures 1 to 4This invention describes an electrode assembly, a winding core, and a battery according to embodiments of the present invention.

[0037] like Figures 1 to 4 As shown, the electrode assembly of this utility model embodiment includes: an electrode 1 and an insulating tape 2. The electrode 1 is either a negative electrode 11 or a positive electrode. The insulating tape 2 is disposed at the end of the electrode 1 along the length direction of the electrode 1. The insulating tape 2 extends along the length direction of the electrode 1. After the electrode assembly is wound up, the insulating tape 2 can be wound into a support column, and the electrode 1 is wound around the outer periphery of the support column.

[0038] According to the electrode assembly of the present invention, since the insulating tape 2 is located at the end of the electrode 1 along the length direction of the electrode 1, after the electrode assembly is wound up, the insulating tape 2 can be wound into a support column, and the electrode 1 is wound around the outer periphery of the support column. Thus, the electrode assembly of the present invention can eliminate the need to set a central tube inside the core, and can avoid the problem of the electrode 1 collapsing in the central area of ​​the core. The manufacturing process is simple and it is beneficial to improve the overall energy density of the battery.

[0039] It is understandable that during the winding process of the cylindrical core, the insulating tape 2, as the starting end of the electrode 1, can be wound into a columnar structure (i.e., a support column). Thus, the wound insulating tape 2 can support the central area of ​​the core, eliminating the need to insert a metal central tube into the central area of ​​the core. This makes the wound core lighter and occupies less space, which is beneficial to improving the overall energy density of the battery.

[0040] Optionally, such as Figure 1 As shown, the insulating tape 2 includes a connecting section 21 and an extension section 22. One end of the connecting section 21 is connected to the electrode 1, and the other end of the connecting section 21 is connected to the extension section 22. In the projection orthogonal to the thickness direction of the electrode 1, the projection of the connecting section 21 overlaps with the projection of the electrode 1. It can be understood that the connecting section 21 overlaps at least partially with the electrode 1 along the thickness direction of the electrode 1, thereby improving the reliability of the connection between the connecting section 21 and the electrode 1.

[0041] For example, the connecting segment 21 can be bonded and fixed to the electrode 1, thereby improving the convenience of connecting the insulating tape 2 to the electrode 1.

[0042] Optionally, such as Figure 1 As shown, before the electrode assembly is wound up, the extension section 22 has a dimension L1 along the length direction of the electrode 1, where 18mm≤L1≤30mm. For example, L1 can be 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, or 30mm.

[0043] The electrode assembly of this utility model, by designing the extension section 22 with the above-mentioned size parameters, can ensure that the insulating tape 2 has sufficient support strength after winding, and can also avoid the problem that the support column formed by the winding of the insulating tape 2 is too large and occupies too much space of the core.

[0044] like Figure 1 As shown, before the electrode assembly is wound up, the dimension of the connecting segment 21 along the length of the electrode 1 is L2, where 4mm ≤ L2 ≤ 6mm. For example, L2 can be 4mm, 5mm, or 6mm. This ensures the strong connection between the electrode 1 and the insulating tape 2, while avoiding the problem of too much space in the winding core due to an excessively long connecting segment 21.

[0045] After the electrode assembly is wound, the extension section 22 has a winding number of turns of T, where 3 ≤ T ≤ 5. For example, T can be 3, 4, or 5. This ensures that the insulating tape 2 has sufficient support strength after winding, while avoiding the problem of the large size of the support column formed by the winding of the insulating tape 2 occupying too much space in the core.

[0046] like Figure 1 As shown, there are two insulating tapes 2, with at least a portion of the electrode 1 located between the two insulating tapes 2, thereby increasing the support strength of the insulating tapes 2 after winding. Furthermore, since the insulating tapes 2 are bonded to the electrode 1, one side of the insulating tape 2 is adhesive. The adhesive sides of the two insulating tapes 2 can be joined together to cover the adhesive side of the insulating tape 2, which helps improve the smoothness of the electrode assembly winding process.

[0047] Optionally, such as Figure 4 As shown, the insulating tape 2 has perforated holes 23. The perforated holes 23 can accelerate the flow of electrolyte to improve the wetting effect in the center area of ​​the core, which is beneficial to improving the overall service life of the battery.

[0048] For example, such as Figure 4 As shown, there are multiple perforated holes 23, which are arranged at intervals on the insulating strip 2. This can further accelerate the flow of electrolyte and improve the wetting effect in the central area of ​​the core.

[0049] The total area of ​​the perforated holes 23 is Q1, and the area of ​​the insulating tape 2 is Q2, where Q1 / Q2 ≥ 0.3. This means that the perforated holes 23 account for more than 30% of the total area of ​​the insulating tape 2. This further accelerates the flow of the electrolyte and improves the wetting effect in the central area of ​​the core.

[0050] For example, the hollow hole 23 can be a round hole, an elliptical hole, a triangular hole or a rectangular hole, and the present invention does not limit it in this respect.

[0051] Optionally, such as Figure 3As shown, one end of the support column protrudes beyond the electrode 1 by a dimension H, where 0 < H ≤ 1 mm. It can be understood that, in the height direction of the core, the height of the insulating tape 2 must exceed the height of the negative (positive) electrode material area of ​​the electrode 1. This improves the support effect of the support column and reduces the probability of collapse in the central area of ​​the core.

[0052] For example, such as Figure 3 As shown, H can be 0.1mm, 0.3mm, 0.5mm, 0.7mm, or 1mm.

[0053] Optionally, such as Figure 1 As shown, the thickness of the insulating tape 2 is M, where 20μm ≤ M ≤ 50μm. For example, M can be 20μm, 30μm, 40μm, or 50μm. This ensures that the insulating tape 2 has sufficient support strength after winding, while avoiding the problem of the large size of the support column formed by the winding of the insulating tape 2 occupying too much space in the core.

[0054] The tensile strength of the insulating tape 2 is ≥100MPa to prevent the insulating tape 2 from breaking during the winding process and to ensure the structural stability of the insulating tape 2.

[0055] For example, insulating tape 2 is one of polyimide tape (PI tape), polyethylene terephthalate tape (PET tape), and ceramic coated tape (PP tape).

[0056] It is understood that electrode 1 can be either a negative electrode 11 or a positive electrode. In the example of this utility model, electrode 1 is a negative electrode 11. During the winding process of the core, the negative electrode 11 is wound before the positive electrode. Therefore, the insulating tape 2 is placed at the starting end of the negative electrode 11, which allows the support column formed by the winding of the insulating tape 2 to be closer to the center of the core.

[0057] like Figure 1 As shown, the negative electrode 11 includes a copper foil 111 and a negative electrode layer 112. The negative electrode layer 112 is coated on the copper foil 111, and the insulating tape 2 is bonded to the negative electrode layer 112, which facilitates the processing and manufacturing of the electrode assembly.

[0058] like Figure 2 and Figure 3 As shown, to facilitate the processing and manufacturing of the core, multiple electrode assemblies can be connected together, with an insulating strip 2 between every two adjacent electrodes 1. Figure 2 As shown, the insulating tape 2 can be cut at the cutting line P to separate two adjacent electrode assemblies.

[0059] For example, such as Figure 2 As shown, the dimension of the insulating tape 2 along the length of the electrode 1 is L0, and the distance of the cutting line P from the previous electrode 1 (e.g.) Figure 1The size of electrode 1 on the left side is L3, and the distance from the cutting line P to the next electrode 1 (e.g.) Figure 1 The size of the electrode 1) on the right side is L1. Among them, L0 is selected between 30mm and 45mm, L1 is selected between 18mm and 30mm, and L3 is selected between 2mm and 4mm.

[0060] Another embodiment of the present invention includes a winding core comprising the electrode assembly of the present invention.

[0061] According to the embodiment of the present invention, since the insulating tape 2 is located at the end of the electrode 1 along the length direction of the electrode 1, after the electrode assembly is wound up, the insulating tape 2 can be wound into a support column, and the electrode 1 is wound around the outer periphery of the support column. Therefore, the internal structure of the core of the embodiment of the present invention does not need to be provided with a central tube, and the problem of the electrode 1 collapsing in the central area of ​​the core can be avoided. The manufacturing process is simple and it is beneficial to improve the overall energy density of the battery.

[0062] Another embodiment of the battery of this utility model includes the winding core of this utility model. The technical effects of the battery of this utility model are the same as those of the winding core and electrode assembly of this utility model, and will not be described in detail here.

[0063] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0065] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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, an electrical connection, or a connection that allows communication between them; 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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0066] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0067] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0068] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A pole piece assembly, characterized by, include: Electrode (1), wherein the electrode (1) is one of a negative electrode (11) and a positive electrode; Insulating tape (2) is provided at the end of the electrode (1) along the length direction of the electrode (1). The insulating tape (2) extends along the length direction of the electrode (1). After the electrode assembly is wound up, the insulating tape (2) can be wound into a support column, and the electrode (1) is wound around the outer periphery of the support column.

2. The pole piece assembly of claim 1, wherein, The insulating tape (2) includes a connecting section (21) and an extension section (22). One end of the connecting section (21) is connected to the electrode (1), and the other end of the connecting section (21) is connected to the extension section (22). In the projection orthogonal to the thickness direction of the electrode (1), the projection of the connecting section (21) overlaps with the projection of the electrode (1).

3. The pole piece assembly of claim 2, wherein, Before the electrode assembly is wound up, the extension section (22) has a dimension of L1 along the length direction of the electrode (1), wherein 18mm≤L1≤30mm; And / or, before the electrode assembly is wound up, the dimension of the connecting segment (21) along the length direction of the electrode (1) is L2, wherein 4mm≤L2≤6mm; And / or, after the electrode assembly is wound, the extension section (22) has a winding number of turns of T, where 3≤T≤5.

4. The pole piece assembly of claim 1, wherein, There are two insulating strips (2), and at least part of the electrode (1) is located between the two insulating strips (2).

5. The pole piece assembly of claim 1, wherein, The insulating tape (2) is provided with perforated holes (23).

6. The pole piece assembly of claim 5, wherein, There are multiple hollow holes (23), and the multiple hollow holes (23) are arranged at intervals on the insulating strip (2); And / or, the total area of ​​the hollow hole (23) is Q1, and the area of ​​the insulating tape (2) is Q2, wherein Q1 / Q2≥0.

3.

7. The pole piece assembly of any of claims 1-6, wherein, The dimension of the support column protruding from the electrode (1) at one end along its axial direction is H, where 0 < H ≤ 1 mm; And / or, the thickness of the insulating tape (2) is M, wherein 20μm≤M≤50μm; And / or, the tensile strength of the insulating tape (2) is ≥100MPa; And / or, the insulating tape (2) is one of polyimide tape, polyethylene terephthalate tape, and ceramic coated tape; And / or, the insulating tape (2) is bonded to the electrode (1).

8. The pole piece assembly of any of claims 1-6, wherein, The electrode (1) is a negative electrode (11), which includes a copper foil (111) and a negative electrode layer (112). The negative electrode layer (112) is coated on the copper foil (111), and the insulating tape (2) is bonded to the negative electrode layer (112).

9. A core, characterized by The electrode assembly includes any one of claims 1-8.

10. A battery, characterized in that, Includes the core as described in claim 9.

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