Cylindrical battery insulation sheet and cylindrical battery

Abstract

The utility model discloses a cylindrical battery insulating sheet and a cylindrical battery, the cylindrical battery insulating sheet comprises an insulator and a swelling body which are sequentially laminated, the middle part of the insulating sheet is provided with a through hole penetrating through the insulator and the swelling body, and the swelling body can absorb electrolyte to generate volume expansion. And after expansion, the volume is increased to fill a gap between the end part of the roll core and the shell, so that the position of the roll core is further stabilized, the roll core is prevented from shaking left and right in the shell, the problem of pseudo soldering or welding failure caused by pulling a welding point due to left-right shaking of the roll core is avoided, and the shaking resistance and vibration resistance can be effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of secondary batteries, in particular to a cylindrical battery insulating sheet and a cylindrical battery. Background Art

[0002] In the field of battery technology, cylindrical batteries are widely used in various portable electronic devices, power tools, and electric vehicles due to their compact structure and high energy density. Despite their widespread use, cylindrical batteries still have some structural stability issues during actual use. In particular, external vibration and impact during handling and transportation can cause internal connection points, especially the welds between the negative electrode tab and the battery casing, to become cold or loose. This problem not only affects battery reliability but can also lead to performance degradation and even failure.

[0003] In traditional cylindrical battery designs, the negative electrode tab is typically welded to the bottom of the battery casing via spot welding. While this welding method can meet basic mechanical fastening and electrical connection requirements in most cases, under severe shaking or prolonged vibration conditions, the welds may break or fall off due to concentrated mechanical stress. This problem is particularly prominent in batteries used in high-vibration environments such as power tools.

[0004] In addition, although existing cylindrical battery designs include insulating sheets to prevent direct contact between the positive electrode and the shell to avoid short circuits, these insulating sheets usually do not have the function of alleviating the impact of vibration on the welding point between the tab and the shell.

[0005] Therefore, how to design an insulating sheet that can provide necessary insulation protection and significantly enhance the structural stability of the battery tab and shell welds under shaking and vibration environments has become a technical problem that needs to be solved urgently in the industry. Utility Model Content

[0006] The purpose of the utility model is to provide a cylindrical battery insulating sheet to improve the anti-shake and vibration resistance of the cylindrical battery in response to the deficiencies of the prior art.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A cylindrical battery insulating sheet comprises an insulator and a swelling body stacked in sequence, wherein a through hole penetrating the insulator and the swelling body is provided in the middle of the insulating sheet, and the swelling body can absorb electrolyte to expand in volume.

[0009] Preferably, the insulator includes a first adhesive layer, an insulating base material layer and a second adhesive layer, and the insulating base material layer is arranged between the first adhesive layer and the second adhesive layer.

[0010] Preferably, the swelling body includes a first swelling layer, a supporting substrate layer and a second swelling layer, and the supporting substrate layer is arranged between the first swelling layer and the second swelling layer.

[0011] Preferably, the diameter of the insulator is 15-25 mm, and the diameter of the through hole is 3-8 mm.

[0012] Preferably, the total thickness of the insulator is 0.1-0.3 mm.

[0013] Preferably, the thickness of the swollen body is 0.1-0.3 mm.

[0014] Preferably, the thickness of the first adhesive layer and the second adhesive layer is respectively 20-25% of the total thickness of the insulator, and the thickness of the insulating base material layer is 50-60% of the total thickness of the insulator.

[0015] Preferably, the thickness of the first swelling layer and the second swelling layer are respectively 50-60% of the total thickness of the swelling body, and the thickness of the supporting substrate layer is 20-25% of the total thickness of the swelling body.

[0016] Preferably, the material of the first swelling layer and the second swelling layer are both one of polyacrylic acid resin, polyacrylamide resin and polyacrylate resin.

[0017] In addition, the present invention also provides a cylindrical battery, comprising a shell and a winding core arranged in the shell, and also comprising the cylindrical battery insulating sheet described in any of the above paragraphs.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1) The utility model provides a cylindrical battery insulating sheet, comprising an insulator and a swelling body stacked in sequence, wherein the swelling body can absorb electrolyte to expand in volume. After swelling, the volume increases to fill the gap between the end of the winding core and the outer shell, further stabilizing the position of the winding core and preventing the winding core from shaking left and right in the outer shell, avoiding the problem of cold welding or welding failure caused by pulling the welding point due to the shaking of the winding core, and can effectively improve the resistance to shake and vibration.

[0020] 2) The utility model provides a cylindrical battery insulating sheet, comprising an insulator and a swelling body stacked in sequence, wherein the insulator comprises a first adhesive layer, an insulating base material layer and a second adhesive layer. The main function of the adhesive layer is to bond the core and the shell to prevent the core from shaking in the vertical direction during shaking and vibration. The core does not shake, which avoids the pulling of the welding point between the electrode tab and the shell caused by shaking, and avoids the problem of cold welding or welding failure caused by pulling the welding point due to the up and down shaking of the core. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a cylindrical battery insulating sheet according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of an insulator according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the cross-sectional structure of a swelling body according to an embodiment of the present invention.

[0024] Among them, 1-insulator; 2-swelling body; 3-through hole; 11-first bonding layer; 12-insulating substrate layer; 13-second bonding layer; 21-first swelling layer; 22-supporting substrate layer; 23-second swelling layer. DETAILED DESCRIPTION

[0025] In order to make the technical solutions and advantages of the present invention clearer, the present invention and its beneficial effects will be described in further detail below in conjunction with specific implementation methods and the accompanying drawings, but the implementation methods of the present invention are not limited thereto.

[0026] 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 the technical features being referred to. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0027] In order to make the technical solutions and advantages of the present invention clearer, the present invention and its beneficial effects will be described in further detail below in conjunction with specific implementation methods and the accompanying drawings, but the implementation methods of the present invention are not limited thereto.

[0028] like Figure 1-3 As shown, according to the first aspect of the present application, the present application aims to provide a cylindrical battery insulation sheet, comprising an insulator 1 and a swelling body 2 stacked in sequence. A through hole 3 is provided in the middle of the insulation sheet 1, penetrating the insulator 1 and the swelling body 2. The swelling body 2 can absorb electrolyte and expand in volume. After the swelling body absorbs the electrolyte and expands in volume, it can wrap around the winding core, filling the gap between the winding core and the outer shell, thereby preventing the winding core from swaying left and right within the outer shell. This avoids the problem of cold solder joints or welding failure caused by the winding core swaying and pulling the welding points, and can effectively improve the anti-shake resistance and vibration resistance.

[0029] In some embodiments, the insulator 1 includes a first adhesive layer 11, an insulating base material layer 12, and a second adhesive layer 13, wherein the insulating base material layer 12 is disposed between the first adhesive layer 12 and the second adhesive layer 13. The first adhesive layer and the second adhesive layer in the insulator serve to bond the winding core to the outer shell, thereby preventing the winding core from shaking in the vertical direction during shaking and vibration. The winding core does not shake, thereby avoiding the pulling of the welding point between the negative electrode tab and the outer shell due to shaking, and avoiding the problem of cold welding or welding failure caused by pulling the welding point due to the up and down shaking of the winding core. In addition to serving as a supporting adhesive layer, the insulating base material layer also has a certain strength and good insulation properties, which can prevent the pole piece from piercing the insulating piece and contacting the outer shell to form a short circuit.

[0030] In some embodiments, the materials of the first adhesive layer and the second adhesive layer are both selected from the group consisting of polyvinyl alcohol resin, polyamide resin, epoxy resin, and polyurethane resin.

[0031] In some embodiments, the swelling body 2 includes a first swelling layer 21 , a supporting substrate layer 22 and a second swelling layer 23 , wherein the supporting substrate layer 22 is disposed between the first swelling layer 21 and the second swelling layer 23 .

[0032] In some embodiments, the insulating substrate layer 12 and the supporting substrate layer 22 are both made of one of polyethylene, polypropylene, and polyvinyl chloride.

[0033] In some embodiments, the diameter of the insulator 1 is 15-25 mm, for example, 15 mm, 18 mm, 20 mm, 22 mm, or 25 mm. The diameter of the through hole 3 is 3-8 mm, for example, 3 mm, 5 mm, or 8 mm, ensuring sufficient space for electrode extraction and electrolyte injection.

[0034] In some embodiments, the total thickness of the insulator 1 is 0.1-0.3 mm, for example, 0.1 mm, 0.2 mm, or 0.3 mm. This thickness range provides sufficient insulation protection without significantly increasing the overall volume of the battery, thereby maintaining a high energy density of the battery.

[0035] In some embodiments, the total thickness of the swelling body 2 is 0.1-0.3 mm, for example, 0.1 mm, 0.2 mm, or 0.3 mm. This thickness range can provide sufficient electrolyte absorption and expansion space without excessively increasing the internal pressure of the battery.

[0036] In some embodiments, the thickness of the first adhesive layer 11 and the second adhesive layer 13 is 20-25% of the total thickness of the insulator 1, for example, it can be 20%, 21%, 22%, 23%, 24% or 25%; the thickness of the insulating substrate layer 12 is 50-60% of the total thickness of the insulator 1, for example, it can be 50%, 52%, 54%, 56%, 58% or 60%.

[0037] In some embodiments, the thickness of the first swelling layer 21 and the second swelling layer 23 is 50-60% of the total thickness of the swelling body 2, for example, it can be 50%, 52%, 54%, 56%, 58% or 60%; the thickness of the supporting substrate layer 22 is 20-25% of the total thickness of the swelling body 2, for example, it can be 20%, 21%, 22%, 23%, 24% or 25%.

[0038] In some embodiments, the first swelling layer 21 and the second swelling layer 23 are each made of a polyacrylic acid resin, a polyacrylamide resin, or a polyacrylate resin. These materials have excellent electrolyte absorption and chemical stability, enabling the battery to maintain good performance over long periods of use. It should be noted that other materials capable of absorbing electrolyte and expanding in volume may also be used.

[0039] According to a second aspect of the present application, a cylindrical battery is provided, comprising a battery housing and a winding core, wherein the winding core comprises a positive electrode sheet, a separator, and a negative electrode sheet stacked and wound in sequence, and further comprises the aforementioned cylindrical battery insulating sheet. Application of this insulating sheet to cylindrical batteries can significantly improve the overall performance and reliability of the battery, particularly its service life in high-vibration environments.

[0040] In some embodiments, an insulating sheet is placed between the end of the cylindrical battery's core and the outer casing. The swollen portion of the insulating sheet simultaneously wraps around the negative-end core. The core and insulating sheet are then placed together in the outer casing, and the negative electrode tab is welded to the outer casing through a through-hole in the insulating sheet. Due to the weight of the core itself, the insulating portion of the insulating sheet firmly bonds the core to the outer casing, preventing the core from swaying and pulling on the weld. Meanwhile, the swollen portion of the negative-end core begins to absorb liquid after the battery cell is injected. As the swollen portion expands, it fills the gap between the core and the outer casing, reducing the space for the core to sway side to side, which could cause tension on the weld.

[0041] Based on the disclosure and teachings of the above description, those skilled in the art will be able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above. Any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention fall within the scope of protection of the present invention. In addition, although certain specific terms are used in this description, these terms are for convenience only and do not constitute any limitation on the present invention.

Claims

1. A cylindrical battery insulating sheet, characterized in that: The invention comprises an insulator and a swelling body which are stacked in sequence. A through hole which penetrates the insulator and the swelling body is provided in the middle of the insulating sheet. The swelling body can absorb electrolyte to expand in volume.

2. The cylindrical battery insulating sheet according to claim 1, characterized in that: The insulator includes a first adhesive layer, an insulating base material layer, and a second adhesive layer, wherein the insulating base material layer is disposed between the first adhesive layer and the second adhesive layer.

3. The cylindrical battery insulating sheet according to claim 1, characterized in that: The swelling body includes a first swelling layer, a supporting substrate layer, and a second swelling layer, wherein the supporting substrate layer is disposed between the first swelling layer and the second swelling layer.

4. The cylindrical battery insulating sheet according to claim 1, characterized in that: The diameter of the insulator is 15-25 mm, and the diameter of the through hole is 3-8 mm.

5. The cylindrical battery insulating sheet according to claim 1, characterized in that: The total thickness of the insulator is 0.1-0.3 mm.

6. The cylindrical battery insulating sheet according to claim 1, characterized in that: The total thickness of the swollen body is 0.1-0.3 mm.

7. The cylindrical battery insulating sheet according to claim 2, characterized in that: The thickness of the first adhesive layer and the second adhesive layer are respectively 20-25% of the total thickness of the insulator, and the thickness of the insulating base material layer is 50-60% of the total thickness of the insulator.

8. The cylindrical battery insulating sheet according to claim 3, characterized in that: The thickness of the first swelling layer and the second swelling layer are respectively 50-60% of the total thickness of the swelling body, and the thickness of the supporting substrate layer is 20-25% of the total thickness of the swelling body.

9. The cylindrical battery insulating sheet according to claim 3, characterized in that: The first swelling layer and the second swelling layer are both made of one of polyacrylic acid resin, polyacrylamide resin and polyacrylate resin.

10. A cylindrical battery comprising a housing and a winding core disposed within the housing, characterized in that: It also includes the cylindrical battery insulating sheet according to any one of claims 1 to 9.

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