Adhesive tape for lithium ion battery

Abstract

The utility model provides an adhesive tape for a lithium ion battery. The adhesive tape comprises a base material layer and an adhesive layer, the lower surface of the base material layer is coated with the adhesive layer, the width of the adhesive layer is smaller than that of the base material layer, non-adhesive areas are formed on the two sides of the adhesive layer, and the widths of the two non-adhesive areas are equal. According to the adhesive tape for the lithium ion battery, due to the arrangement of the non-adhesive areas on the two sides of the adhesive, when the adhesive tape is rolled, the adhesive in the adhesive layer only diffuses into the non-adhesive areas, and the adhesive is prevented from overflowing out of the base material layer, so that the phenomenon that a battery pole piece is broken due to the fact that the adhesive tape and the battery pole piece adhere to a roller is avoided; and continuous production of a battery pole piece production line is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium - ion batteries, and particularly relates to a tape for lithium - ion batteries. Background Art

[0002] With the rapid development of lithium - ion battery technology, its applications in fields such as portable electronic devices, electric vehicles, and energy storage systems are becoming increasingly widespread. During the production process of lithium - ion batteries, as an important auxiliary material, tapes are widely used in multiple links such as cell manufacturing, outer shell encapsulation, and tab insulation.

[0003] In the rolling process of the cell electrode, traditional tapes have many deficiencies. For example, during the process of changing the roll and splicing the tape of the battery electrode, it is necessary to use the tape to bond the battery electrode, and this tape will pass through high - temperature rolling with the battery electrode.

[0004] If traditional tapes are used, when the tapes are rolled, under high - temperature and high - strength rolling conditions, the glue of traditional tapes is likely to overflow, resulting in the adhesion of the tape or the battery electrode to the pressure roller, and then leading to the fracture of the battery electrode. At this time, in order to prevent the fracture of the battery electrode, when the battery electrode passes through the roller, it is necessary to relieve the pressure of the pressure roller and skip the part bonded with the tape, which will cause a certain length of the battery electrode roll to be scrapped, and at the same time consume a certain amount of time for adjusting the pressure roller, thus seriously affecting the continuous production of the battery electrode production line. Summary of the Utility Model

[0005] In view of this, the utility model aims to provide a tape for lithium - ion batteries, which can prevent the glue from overflowing and ensure the continuous production of the battery electrode production line.

[0006] To achieve the above - mentioned purpose, the technical solution of the utility model is realized as follows:

[0007] A tape for lithium - ion batteries includes a base material layer and an adhesive layer; the adhesive layer is coated on the lower surface of the base material layer, the width of the adhesive layer is smaller than the width of the base material layer, non - adhesive areas are formed on both sides of the adhesive layer, and the widths of the two non - adhesive areas are equal.

[0008] Furthermore, the base material layer includes a PET film layer or a PI film layer.

[0009] Furthermore, the thickness H1 of the base material layer satisfies: 5μm ≤ H1 ≤ 15μm.

[0010] Furthermore, the width W1 of the base material layer and the width W2 of the adhesive layer satisfy: 0.1*W1 ≤ W2 ≤ 0.7*W1.

[0011] Furthermore, the thickness H2 of the adhesive layer satisfies: 2μm ≤ H2 ≤ 12μm.

[0012] Further, the adhesive layer includes a plurality of adhesive blocks arranged at intervals in an array along the length direction of the base material layer.

[0013] Further, the adhesive layer includes one of an acrylic glue coating, a rubber glue coating, and a silicone glue coating.

[0014] Further, it further includes: a release layer, the release layer is attached to the lower surface of the base material layer; the width of the release layer is equal to the width of the base material layer, and the adhesive layer is interposed between the release layer and the base material layer.

[0015] Further, the release layer includes one of a PET film layer, a PI film layer, and a PP film layer.

[0016] Further, the thickness H3 of the release layer satisfies: 5μm ≤ H1 ≤ 25μm.

[0017] Compared with the prior art, the present utility model has the following advantages:

[0018] For the tape for lithium-ion batteries of the present utility model, through the setting of the non-adhesive areas on both sides of the glue, when the tape is roll-pressed, the glue in the adhesive layer will only diffuse into the non-adhesive areas, avoiding the glue from overflowing outside the base material layer, thereby avoiding the fracture of the battery electrode due to the adhesion of the tape and the battery electrode to the roller, and ensuring the continuous production of the battery electrode production line.

[0019] In addition, the base material layer includes a PET film layer or a PI film layer, and both the PET film layer and the PI film layer have good high-temperature resistance and mechanical strength, thereby preventing the tape from being damaged by high temperature and improving the high-temperature resistance and mechanical strength of the base material layer and the tape as a whole. The setting of the thickness H1 of the base material layer ensures that the base material layer has sufficient structural strength and can prevent the tape from cracking during the roll-pressing process and causing glue overflow. The setting of the numerical relationship between the width W1 of the base material layer and the width W2 of the adhesive layer makes the width of the non-adhesive areas on both sides of the adhesive layer appropriate, capable of accommodating the diffused and flowing glue and preventing the glue from overflowing.

[0020] In addition, the setting of the thickness H2 of the adhesive layer, while avoiding the overflow of the glue, ensures that there is sufficient glue in the adhesive layer for bonding the battery electrode and improves the bonding effect. The adhesive layer includes a plurality of adhesive blocks arranged in an array. The adhesive blocks are spaced apart from each other. When the adhesive layer is roll-pressed, the glue in each adhesive block diffuses and flows along the circumferential direction of the adhesive block, and the flowing glue can fill the gaps between the adhesive blocks to prevent the glue from overflowing. The adhesive layer includes one of an acrylic glue coating, a rubber glue coating, and a silicone glue coating to improve the bonding effect of the tape in this embodiment and prevent the tape from detaching from the battery electrode.

[0021] Furthermore, the tape further includes a release layer. Through the provision of the release layer, during the winding process of the tape, it can prevent the adhesive layer in one layer of the tape from adhering to the substrate layer of another layer of the tape, thereby facilitating the winding of the tape. Moreover, the release layer can protect the substrate layer and the adhesive layer, which is beneficial to the production and use of the tape. The release layer includes one of a PET film layer, a PI film layer, and a PP film layer, enabling the release layer to have good mechanical properties and be able to withstand folding and bending without tearing, thereby improving the overall structural strength of the tape and making the release layer have an appropriate release force to facilitate the peeling of the release layer from the substrate layer and the use of the tape. The setting of the thickness H3 of the release layer can improve the structural strength of the release layer, thereby ensuring the protective effect of the release layer on the substrate layer and the adhesive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation of the present utility model. In the drawings:

[0023] Figure 1 is a cross-sectional view of the tape for a lithium-ion battery according to an embodiment of the present utility model;

[0024] Figure 2 is a schematic layout diagram of the adhesive blocks in the adhesive layer according to an embodiment of the present utility model;

[0025] Figure 3 is a schematic layout diagram of the adhesive blocks in another embodiment form of the adhesive layer according to an embodiment of the present utility model;

[0026] Description of the reference numerals:

[0027] 1. Substrate layer; 101. Non-adhesive area;

[0028] 2. Adhesive layer; 201. Adhesive block;

[0029] 3. Release layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0031] In the following description, specific details such as specific system structures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0032] In the description of the present utility model, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present utility model. In addition, if terms such as "first", "second", etc. appear, they are also only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0033] In addition, in the description of the present utility model, unless otherwise clearly defined, the terms "installation", "connection", "connection", "connector" 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood in combination with specific situations.

[0034] The present utility model will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0035] This embodiment relates to a tape for a lithium-ion battery, which can be used to bond battery electrodes during the rolling process of battery electrode sheets. In terms of the overall structure, as Figure 1 shown, the tape of this embodiment includes a base material layer 1 and an adhesive layer 2.

[0036] Among them, the adhesive layer 2 is coated on the lower surface of the base material layer 1. The width of the adhesive layer 2 is smaller than the width of the base material layer 1. Non-adhesive areas 101 are formed on both sides of the adhesive layer 2, and the widths of the two non-adhesive areas 101 are equal. It can be understood that when the tape of this embodiment passes through the rolling process with the battery electrode sheet, the base material layer 1 and the adhesive layer 2 of the tape will be extruded. When the adhesive layer 2 is extruded, the glue constituting the adhesive layer 2 will diffuse and flow into the non-adhesive areas 101 along the transverse direction. At the same time, the widths of the two non-adhesive areas 101 are equal, which can prevent the glue from overflowing from one side of the base material layer 1.

[0037] As described above, through the setting of the non-adhesive areas 101 on both sides of the glue, when the tape of this embodiment is rolled, the glue in the adhesive layer 2 will only diffuse into the non-adhesive areas 101, avoiding the glue from overflowing outside the base material layer 1, thereby avoiding the fracture of the battery electrode sheet caused by the adhesion of the tape and the battery electrode sheet to the roller, and ensuring the continuous production of the battery electrode sheet production line.

[0038] Based on the above overall introduction, specifically, the tape of this embodiment is applied to the production process of battery electrodes of lithium-ion batteries. During the rolling process of battery electrodes, adopting an appropriate rolling temperature can improve the density and uniformity of battery electrodes, thereby enhancing the energy density and cycling performance of the battery. Rolling at a specific temperature can reduce the internal resistance of the electrode, increase the density of the battery electrode, and thus improve the discharge capacity and stability of the battery. In addition, a suitable rolling temperature also helps to improve the mechanical strength of the battery electrode and enhance the safety of the battery.

[0039] Since the tape of this embodiment also undergoes rolling with the battery electrode, to improve the structural strength of the substrate layer 1 and prevent the tape from being damaged by high temperature, the substrate layer 1 of this embodiment includes a PET film layer or a PI film layer. Both the PET film layer and the PI film layer have good high-temperature resistance and mechanical strength. The PET film layer can be used in an environment of 120°C and can be used for a short time in an environment of 150°C, while the PI film layer can be used for a long time in an environment of 280°C and can be used at a temperature of 400°C for a short time, thereby preventing the tape from being damaged by high temperature and improving the high-temperature resistance and mechanical strength of the substrate layer 1 and the overall tape. In specific implementation, due to the difference in the temperature adaptation range between the PET film layer and the PI film layer, when producing the tape of this embodiment, the specific material of the substrate layer 1 can be selected according to the rolling temperature of the battery electrode to which the tape is applied, while ensuring that the tape has appropriate high-temperature resistance and mechanical strength and minimizing the production cost of the tape of this embodiment as much as possible.

[0040] To further improve the structural strength of the substrate layer 1 and facilitate the production of battery electrodes, the thickness H1 of the substrate layer 1 of this embodiment satisfies: 5μm ≤ H1 ≤ 15μm, so as to ensure that the substrate layer 1 has sufficient structural strength to prevent the tape from cracking and causing glue overflow during the rolling process. And through the setting of the thickness range of the substrate layer 1, while ensuring the structural strength of the tape, it can be ensured that during the subsequent die-cutting process of the battery electrode roll, the cutting knife can cut the tape, thus facilitating the production of battery electrodes. When the substrate layer 1 is too thin, the strength of the substrate layer 1 is limited and it is easy to break and cause glue overflow, while when the substrate layer 1 is too thick, it is difficult for the cutting knife to cut the tape, resulting in the need for rework of the battery electrode. In specific implementation, the thickness H1 of the substrate layer 1 of this embodiment can be set to 5μm, 10μm, or 15μm, etc.

[0041] In this embodiment, by setting the glue-free area 101, a certain accommodation space is provided for the glue that diffuses and flows due to rolling. To prevent the glue from overflowing, the width W1 of the base material layer 1 and the width W2 of the glue layer 2 in this embodiment satisfy: 0.1*W1 ≤ W2 ≤ 0.7*W1, so that the widths of the glue-free areas 101 on both sides of the glue layer 2 are appropriate, capable of accommodating the diffused and flowing glue and preventing the glue from overflowing. When the glue layer 2 is too narrow, the adhesive area is too small, and it is difficult for the tape to stably adhere to the battery electrode. When the glue layer 2 is too wide, the area of the glue layer 2 is large, its glue content is high, and during rolling, the amount of diffused and flowing glue is large, while the width of the glue-free area 101 is too small, and the flowing glue will fill the glue-free area 101 and overflow outside the base material layer 1. In this embodiment, the width W2 of the glue layer 2 can be set to 0.25*W2, 0.3*W2, 0.5*W2, 0.7*W2, etc., to ensure that the glue layer 2 has sufficient adhesive area and at the same time can avoid glue overflow.

[0042] To ensure the bonding effect of the tape, the thickness H2 of the glue layer 2 in this embodiment satisfies: 2μm ≤ H2 ≤ 12μm, while avoiding glue overflow, ensuring that there is sufficient glue in the glue layer 2 for bonding the battery electrode and improving the bonding effect. When the glue layer 2 is too thin, the amount of glue in the glue layer 2 is too small, and the bonding effect between the tape and the battery electrode is poor. When the glue layer 2 is too thick, when the glue layer 2 is rolled, the amount of overflowing glue in the glue layer 2 is large, and the glue is easy to overflow outside the base material layer 1, resulting in the occurrence of sticky roller conditions. In this embodiment, the thickness H2 of the glue layer 2 can be set to 2μm, 4μm, 6μm, 10μm, 12μm, etc.

[0043] The glue layer 2 of this embodiment can be uniformly and continuously coated on the base material layer 1. To further prevent glue overflow while ensuring the bonding effect of the tape, as Figure 2 and Figure 3 shown, the glue layer 2 of this embodiment includes a plurality of glue blocks 201 arranged at intervals in an array along the length direction of the base material layer 1. It can be understood that the glue blocks 201 are arranged at intervals. When the glue layer 2 is rolled, the glue in each glue block 201 diffuses and flows along the circumferential direction of the glue block 201, and the flowing glue can fill the gaps between the glue blocks 201, so as to ensure that the glue layer 2 has sufficient adhesive area while reducing the flowing area of the glue due to rolling and preventing the glue from overflowing. In addition, by arranging a plurality of glue blocks 201 at intervals in an array, the coating amount of the glue in the glue layer 2 can be reduced, thereby reducing the production cost of the tape to a certain extent. In specific implementation, each glue block 201 can be circular or rectangular and is coated on the base material layer 1 at intervals in an array.

[0044] In this embodiment, the adhesive layer 2 includes one of an acrylic glue coating, a rubber glue coating, and a silicone glue coating. By providing the above glue coating, the bonding effect of the tape in this embodiment is improved, and the tape is prevented from detaching from the battery electrode.

[0045] In addition, the tape of this embodiment further includes a release layer 3. Among them, the release layer 3 is attached to the lower surface of the substrate layer 1. The width of the release layer 3 is equal to the width of the substrate layer 1, and an adhesive layer 2 is interposed between the release layer 3 and the substrate layer 1. The edge of the release layer 3 fits the non-adhesive area 101 of the substrate layer 1. It can be understood that during the production of the tape in this embodiment, the tape needs to be wound into a roll. By providing the release layer 3, during the winding process of the tape, the adhesive layer 2 in one layer of the tape can be prevented from adhering to the substrate layer 1 of another layer of the tape, thus facilitating the winding of the tape. And the release layer 3 can protect the substrate layer 1 and the adhesive layer 2, which is beneficial to the production and use of the tape. When using the tape, the release layer 3 needs to be peeled off from the substrate layer 1, and then the tape is bonded to the battery electrode.

[0046] Specifically, the release layer 3 of this embodiment includes one of a PET film layer, a PI film layer, and a PP film layer. By using the above film layer to form the release layer 3, the release layer 3 has good mechanical properties and can withstand folding and bending without tearing, thereby improving the overall structural strength of the tape. At the same time, by using the above film layer, the release layer 3 has an appropriate release force, so as to facilitate the peeling of the release layer 3 from the substrate layer 1 and facilitate the use of the tape.

[0047] Finally, the thickness H3 of the release layer 3 in this embodiment satisfies: 5μm ≤ H1 ≤ 25μm, so as to improve the structural strength of the release layer 3, thereby ensuring the protective effect of the release layer 3 on the substrate layer 1 and the adhesive layer 2. When the release layer 3 is too thin, the release layer 3 is easily torn and the adhesive layer 2 is exposed, making it difficult to protect the substrate layer 1 and the adhesive layer 2. When the release layer 3 is too thick, the overall thickness of the tape will increase, which is not conducive to the winding of the tape. At the same time, since the release layer 3 will be peeled off from the tape during use and the release layer 3 itself will not have an additional effect on the bonding between the tape and the battery electrode, so when the release layer 3 is too thick, it will cause material waste and increase the production cost of the tape. In this embodiment, the thickness of the release layer 3 can be set to 5μm, 10μm, 15μm, 20μm or 25μm, etc.

[0048] In summary, for the tape for lithium-ion batteries in this embodiment, through the setting of the non-adhesive areas 101 on both sides of the glue, when the tape in this embodiment is roll-pressed, the glue in the adhesive layer 2 will only diffuse into the non-adhesive areas 101, and the glue is prevented from overflowing outside the substrate layer 1, thereby avoiding the fracture of the battery electrode caused by the sticking of the tape and the battery electrode to the roller, and ensuring the continuous production of the battery electrode production line.

[0049] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An adhesive tape for lithium-ion batteries, characterized in that: including a substrate layer and an adhesive layer; The adhesive layer is coated on the lower surface of the substrate layer, the width of the adhesive layer is smaller than the width of the substrate layer, adhesive-free areas are formed on both sides of the adhesive layer, and the widths of the two adhesive-free areas are equal.

2. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The substrate layer includes a PET film layer or a PI film layer.

3. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The thickness H1 of the substrate layer satisfies: 5 μm≤H1≤15 μm.

4. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The width W1 of the substrate layer and the width W2 of the adhesive layer satisfy: 0.1*W1≤W2≤0.7*W1.

5. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The thickness H2 of the adhesive layer satisfies: 2 μm≤H2≤12 μm.

6. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The adhesive layer includes a plurality of adhesive blocks arranged in an array and spaced apart from each other along the length direction of the substrate layer.

7. The adhesive tape for lithium-ion batteries according to claim 1, characterized in that: The adhesive layer includes one of organic glass glue coating, rubber glue coating and silicone glue coating.

8. The adhesive tape for lithium-ion batteries according to any one of claims 1 to 7, characterized in that: Also includes: A release layer, the release layer being attached to the lower surface of the substrate layer; The width of the release layer is equal to that of the substrate layer, and the adhesive layer is sandwiched between the release layer and the substrate layer.

9. The adhesive tape for lithium-ion batteries according to claim 8, characterized in that: The release layer includes one of a PET film layer, a PI film layer and a PP film layer.

10. The adhesive tape for lithium-ion batteries according to claim 8, characterized in that: The thickness H3 of the release layer satisfies: 5 μm≤H1≤25 μm.

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