A kind of adhesive paper structure and battery cell

Abstract

The utility model belongs to the technical field of battery production and manufacture, concretely relates to a kind of adhesive paper structure and battery cell, including adhesive paper body and conductive layer;The adhesive paper body has the first face and the second face opposite in the thickness direction;The conductive layer is arranged at the first face or the second face, and the conductive layer is arranged along the width direction of the adhesive paper body, for covering the corner area or pole piece broken strip area of battery cell.The utility model solves the problem that battery cell outer ring cathode broken strip cannot be charged and discharged by optimizing adhesive paper structure.

Description

Technical Field

[0001] This utility model belongs to the technical field of battery manufacturing, specifically relating to an adhesive paper structure and a battery cell. Background Technology

[0002] Today, lithium-ion batteries, as a new type of rechargeable battery, have advantages such as high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and environmental friendliness. They have broad application prospects in portable electrical appliances, power tools, large-scale energy storage, and electric transportation power sources.

[0003] Battery doping technology involves adding specific elements to battery materials to improve their electrochemical performance. With the widespread application of battery doping technology, the proportion of silicon doping in the anode is increasing, and the expansion of the cell during cycling is also increasing.

[0004] In the process of realizing this utility model, the inventors discovered that the prior art has at least the following problems:

[0005] As the silicon content of the battery cell increases, its expansion causes a large rebound of the anode, resulting in a large stress on the outermost cathode. There is bevel stress at the junction of the single-sided and double-sided areas of the outermost cathode, which is prone to breakage during cycling. After the cathode breaks, the outermost two cathode rings cannot charge and discharge, resulting in a sudden drop in the battery cell capacity. Utility Model Content

[0006] One of the objectives of this utility model is to provide an adhesive paper structure to address the shortcomings of existing technologies, thereby solving the problem of the inability to charge and discharge the battery cell after the outer cathode band breaks.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An adhesive tape structure includes an adhesive tape body and a conductive layer; the adhesive tape body has a first surface and a second surface opposite to each other in the thickness direction; the conductive layer is disposed on the first surface or the second surface, and the conductive layer extends along the width direction of the adhesive tape body to cover the corner area or electrode break area of ​​the battery cell.

[0009] In some possible implementations, the conductive layer is fixed to the surface of the first or second surface by electroplating or bonding; or

[0010] The surface of the first or second side is provided with a groove, and the conductive layer is fixed to the groove by electroplating or bonding.

[0011] In some possible implementations, the ratio of the length L of the adhesive tape body to the length of the battery cell is 1.01 to 1.05, and the ratio of the width W of the adhesive tape body to the thickness of the battery cell is 1.5 to 2π.

[0012] In some possible implementations, the conductive layer is centrally disposed along the width direction of the adhesive tape body, and the ratio of the width W1 of the conductive layer to the thickness of the battery cell is 0.9 to 1.1π; or

[0013] In some possible implementations, the conductive layer is disposed near one edge of the adhesive tape body in the width direction, the ratio of the width W1 of the conductive layer to the thickness of the battery cell is 0.45 to 0.55π, and the farthest distance W2 between the conductive layer and one edge of the adhesive tape body satisfies the relationship: W2 = 0.45 to 0.55π.

[0014] In some possible implementations, the conductive layer includes a plurality of conductive blocks, which are spaced apart on the surface of the adhesive paper body, and the width L1 of the conductive blocks satisfies the relationship: L1 = 0.08 to 0.2L.

[0015] In some possible implementations, a plurality of the conductive blocks are arranged at equal intervals along the length of the adhesive tape, and the distance L2 between two adjacent conductive blocks satisfies the relationship: L2 = 0.08 to 0.2L, and the proportion of the conductive blocks covering the adhesive tape body is 45% to 55%.

[0016] In some possible implementations, a plurality of conductive blocks are inclined at equal intervals along the length of the adhesive tape, the included angle θ between the conductive blocks and the edge of the conductive layer is 40° to 50°, and the distance L2 between two adjacent conductive blocks satisfies the following relationship:

[0017] L2 = 0.08~0.2L.

[0018] In some possible implementations, the thickness t1 of the conductive layer is 3 to 5 μm, and the sum of the thicknesses t of the conductive layer and the adhesive tape body is 10 to 18 μm.

[0019] In some possible implementations, the adhesive tape body is made of polypropylene, polyethylene terephthalate, or polyimide, and the conductive layer is made of aluminum, nickel, or stainless steel.

[0020] The second objective of this utility model is to provide a battery cell, including a battery cell and an adhesive paper structure as described above, wherein the battery cell has a corner area or an electrode break area, and the conductive layer covers the corner area or the electrode break area.

[0021] One of the above technical solutions has the following beneficial effects.

[0022] This invention optimizes the adhesive tape structure by plating a metal material on the first or second side of the adhesive tape body. The conductive layer is designed on one side of the adhesive tape body, that is, the conductive layer is formed on the side of the adhesive tape body facing the positive electrode of the battery cell after winding. Moreover, the conductive layer covers the entire corner area of ​​the battery cell. Even if the cathode band breaks in the corner area of ​​the outer ring of the battery cell, the conductive layer on the adhesive tape body can still conduct electricity without changing the structure of the battery cell. This solves the problem of the inability to charge and discharge after the cathode band breaks in the outer ring of the battery cell, and avoids the situation of sudden drop in battery cell capacity. Attached Figure Description

[0023] The features, advantages and technical effects of exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0024] Figure 1 This is a front structural diagram of Embodiment 1 of this utility model.

[0025] Figure 2 This is a side view of Embodiment 1 of the present invention.

[0026] Figure 3 This is a front structural diagram of Embodiment 5 of this utility model.

[0027] Figure 4 This is a side view of Embodiment 5 of the present invention.

[0028] Figure 5 This is a front structural diagram of Embodiment 7 of this utility model.

[0029] Figure 6 This is a side view of Embodiment 7 of the present invention.

[0030] Figure 7 This is a front structural diagram of Embodiment 9 of this utility model.

[0031] Figure 8 This is a side view of embodiment 9 of the present invention.

[0032] Figure 9 This is a schematic diagram of the battery cell structure of this utility model.

[0033] The reference numerals in the attached figures are explained as follows:

[0034] 1-Tape body;

[0035] 2-Conductive layer; 21-Conductive block;

[0036] 3-Cell; 31-Corner area; 32-Electrode breakage area; 33-Straight area;

[0037] X - Length direction;

[0038] Y-width direction;

[0039] Z - Thickness direction. Detailed Implementation

[0040] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0041] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] The following is in conjunction with the appendix Figures 1-9 The present invention will be described in further detail, but this is not intended to limit the scope of the present invention.

[0044] Example 1

[0045] As the silicon content of the battery cell increases, its expansion causes a large rebound of the anode, resulting in a large stress on the outermost cathode. There is bevel stress at the junction of the single-sided and double-sided areas of the outermost cathode, which is prone to breakage during cycling. After the cathode breaks, the outermost two cathode rings cannot charge and discharge, resulting in a sudden drop in the battery cell capacity.

[0046] like Figures 1-2As shown, the adhesive tape structure of this utility model includes an adhesive tape body 1 and a conductive layer 2. The adhesive tape body 1 has a first surface and a second surface opposite to each other in the thickness direction Z. The conductive layer 2 is disposed on the first surface or the second surface and extends along the width direction Y of the adhesive tape body 1, covering the corner area 31 of the battery cell 3. This utility model optimizes the adhesive tape structure by plating a metal material on the first surface or the second surface of the adhesive tape body 1. The conductive layer 2 is designed on one side of the adhesive tape body 1, that is, the conductive layer 2 is formed on the surface of the adhesive tape body 1. Moreover, the conductive layer 2 covers the entire corner area 31 of the battery cell 3. After the cathode band breaks in the corner area of ​​the outer ring of the battery cell, the conductive layer 2 on the adhesive tape body 1 can conduct electricity without changing the structure of the battery cell. This solves the problem of the inability to charge and discharge after the cathode band breaks in the outer ring of the battery cell and avoids the sudden drop in battery cell capacity.

[0047] It should be noted that the adhesive tape body 1 has a conductive layer 2 designed on one side, with the side of the adhesive tape body 1 having the conductive layer 2 facing the inside of the battery cell. This is used to wrap the broken area of ​​the battery cell, ensuring that the conductive layer 2 connects to the cathode break (after the battery cell is cycled, an initial crack forms in one section of the electrode, and as the number of cycles increases, a through crack forms on the electrode, i.e., the cathode break), forming an electronic connection channel. This ensures that after the single-sided / double-sided junction area of ​​the cathode breaks, it can conduct electricity through the conductive layer 2. Because the cathode electrode has a single-sided coating area and a double-sided coating area, the single-sided / double-sided junction area... This can be understood as the boundary between the single-sided coating area and the double-sided coating area. The battery cell has a corner area and a straight area 33. After winding, the single-sided and double-sided boundary is located at the boundary between the straight area and the corner area of ​​the battery cell. The conductive layer 2 covers the corner area to ensure that the conductive layer 2 can cover the cathode breakage area, that is, cover the single-sided and double-sided boundary. The bonding area on the adhesive tape body 1 covers the straight area 33 of the battery cell 3, which plays a bonding role, ensuring the bonding strength of the adhesive tape, improving the bonding stability between the adhesive tape and the battery cell, and preventing the adhesive tape from falling off during use.

[0048] In the adhesive tape structure according to this utility model, the conductive layer 2 is formed on the surface of the first or second side by electroplating. Specifically, the adhesive tape body 1 forms the conductive layer 2 by electroplating. The conductive layer 2 is preferably an aluminum layer, which helps to improve the conductivity of the conductive layer 2. The aluminum plating process of the adhesive tape includes, but is not limited to, adhesive tape pretreatment, magnetron sputtering of an aluminum seed layer, surface pretreatment, electroplating thickening, water washing, anti-oxidation treatment, and drying. Among these processes, the adhesive tape pretreatment can remove surface dirt and reduce coating defects; in the magnetron sputtering of the aluminum seed layer, an aluminum seed layer is formed by magnetron sputtering to provide a base layer for subsequent electroplating; in the surface pretreatment, surface cleaning is performed to remove impurities; in the electroplating thickening, an aluminum layer is formed by electroplating; in the water washing, the electroplating solution is removed; in the anti-oxidation treatment, an oxide layer is formed on the surface to prevent oxidation during subsequent transport; and in the drying, moisture from the production process is removed.

[0049] In the adhesive tape structure according to this utility model, the ratio of the length L of the adhesive tape body 1 to the length of the battery cell is 1.01 to 1.05, that is, the length L of the adhesive tape body 1 = 1.01 to 1.05 * battery cell length. The length L of the adhesive tape body 1 is slightly larger than the length of the battery cell, for example, the length L of the adhesive tape body 1 = 1.01 * battery cell length, 1.02 * battery cell length, 1.03 * battery cell length, 1.04 * battery cell length, or 1.05 * battery cell length, etc., to ensure that the adhesive tape body 1 covers the portion of the battery cell 3 in the length direction; the width W of the adhesive tape body 1 and The ratio of the cell thickness is 1.5 to 2π, that is, the width W of the adhesive tape body 1 is 1.5 to 2π * cell thickness. For example, the width W of the adhesive tape body 1 is 1.5π * cell thickness, 1.6π * cell thickness, 1.7π * cell thickness, 1.8π * cell thickness, 1.9π * cell thickness, or 2.0π * cell thickness, etc., to ensure that there is sufficient contact area between the adhesive tape and the cell, improve the adhesive tape bonding strength, and prevent the adhesive tape from falling off during use. In this embodiment, the width W of the adhesive tape body 1 is 1.8π * cell thickness.

[0050] In the adhesive tape structure according to this utility model, the conductive layer 2 is centrally located along the width direction Y of the adhesive tape body 1. This central location can be understood as the centerline of the conductive layer 2 coinciding with the centerline of the width direction Y of the adhesive tape body 1. This ensures that the conductive layer 2 covers the corner area 31, guaranteeing that the conductive layer 2 covers the cathode break zone. The area on the adhesive tape body 1 other than the conductive layer 2 is the bonding area, correspondingly covering the straight area 33 of the battery cell 3, thus providing adhesion and ensuring the adhesive strength of the adhesive tape. The width W1 of the conductive layer 2... The ratio of the conductive layer 2 to the cell thickness is 0.9 to 1.1π, that is, the width W1 of the conductive layer 2 is 0.9 to 1.1π * cell thickness. For example, the width W1 of the conductive layer 2 is 0.9π * cell thickness, 1.0π * cell thickness, or 1.1π * cell thickness, etc., to ensure that the corner area 31 of the cell 3 is covered. After the cathode strip breaks in the corner area of ​​the outer ring of the cell, it can conduct electricity through the conductive layer 2 on the adhesive paper body 1. In this embodiment, the width W1 of the conductive layer 2 is 1.0π * cell thickness.

[0051] In the adhesive tape structure according to this utility model, the thickness t1 of the conductive layer 2 is 3 to 5 μm, for example, the thickness t1 of the conductive layer 2 is 3 μm, 4 μm or 5 μm, etc., to reduce the influence of the thickness of the conductive layer 2 on the overall thickness of the battery cell 3, and at the same time to avoid the situation where the resistance increases due to the thickness being too small. The sum of the thicknesses t of the conductive layer 2 and the adhesive tape body 1 is 10 to 18 μm, for example, the sum of the thicknesses t of the conductive layer 2 and the adhesive tape body 1 is 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, etc., to prevent the overall thickness of the adhesive tape from being too thick, resulting in the battery cell being too thick, and at the same time to prevent the adhesive tape body 1 from being too small, resulting in the resistance increasing. In this embodiment, the thickness t1 of the conductive layer 2 is 5 μm.

[0052] In the adhesive tape structure according to this utility model, the material of the adhesive tape body 1 is polypropylene (PP), polyethylene terephthalate (PET) or polyimide (PI), or other battery winding insulating tape commonly used in the art, without limitation. The material of the conductive layer 2 is aluminum, nickel or stainless steel. The conductive layer 2 is preferably made of aluminum, which helps to improve the conductivity of the conductive layer 2. Nickel or stainless steel can also be used, which helps to improve the mechanical strength and corrosion resistance of the conductive layer 2.

[0053] The working principle of this utility model is as follows:

[0054] This invention optimizes the adhesive tape structure by plating a metal material on the first or second side of the adhesive tape body 1. The conductive layer is designed on one side of the adhesive tape body, that is, a conductive layer 2 is formed on the surface of the adhesive tape body 1. Moreover, the conductive layer 2 covers the entire corner area 31 of the battery cell 3. After the cathode band breaks in the corner area of ​​the outer ring of the battery cell, it can conduct electricity through the conductive layer 2 on the adhesive tape body 1 without changing the structure of the battery cell. This solves the problem of being unable to charge and discharge after the cathode band breaks in the outer ring of the battery cell and avoids the situation of sudden drop in battery cell capacity.

[0055] Example 2

[0056] Unlike Example 1, the width W of the adhesive tape body 1 is 1.5π * cell thickness, the width W1 of the conductive layer 2 is 1.0π * cell thickness, and the thickness t1 of the conductive layer 2 is 5μm.

[0057] The other structures are the same as in Example 1, and will not be described again here.

[0058] Example 3

[0059] Unlike Example 1, the width W of the adhesive tape body 1 is 1.8π * cell thickness, the width W1 of the conductive layer 2 is 0.9π * cell thickness, and the thickness t1 of the conductive layer 2 is 5μm.

[0060] The other structures are the same as in Example 1, and will not be described again here.

[0061] Example 4

[0062] Unlike Example 1, the width W of the adhesive tape body 1 is 1.8π * cell thickness, the width W1 of the conductive layer 2 is 1.0π * cell thickness, and the thickness t1 of the conductive layer 2 is 3μm.

[0063] The other structures are the same as in Example 1, and will not be described again here.

[0064] Example 5

[0065] Unlike Example 1: See Figures 3-4As shown, in this embodiment, the conductive layer 2 extends along the width direction Y of the adhesive tape body 1, precisely covering the electrode breakage area 32 of the battery cell 3. This ensures that after the single-sided / double-sided junction area of ​​the cathode breaks, conductivity can be achieved through the conductive layer 2. The conductive layer 2 is positioned near the edge of the adhesive tape body 1 along the width direction Y. Compared to the structure of Embodiment 1, which directly covers the electrode breakage area 32, the conductive layer 2 has a smaller area, eliminating the need to cover the entire large corner area 31, thus saving material. The ratio of the width W1 of the conductive layer 2 to the battery cell thickness is 0.45 to 0.55π, i.e., the width W1 of the conductive layer 2 = 0.45 to 0.55π. The thickness of the battery cell, for example, the width W1 of the conductive layer 2 is 0.45π * battery cell thickness, 0.46π * battery cell thickness, 0.47π * battery cell thickness, 0.48π * battery cell thickness, 0.49π * battery cell thickness, 0.50π * battery cell thickness, 0.51π * battery cell thickness, 0.52π * battery cell thickness, 0.53π * battery cell thickness, 0.54π * battery cell thickness, or 0.55π * battery cell thickness, etc. In this embodiment, the width of the conductive layer 2 is smaller than that of the conductive layer 2 in embodiment 1. This also prevents the area of ​​the conductive layer 2 from being too large, which would encroach on the bonding area of ​​the adhesive tape and affect the bonding effect of the adhesive tape. The farthest distance W2 between the conductive layer 2 and one edge of the adhesive tape body 1 satisfies the relationship: W2 = 0.45~0.55W. Specifically, the conductive layer 2 is biased towards one edge of the adhesive tape body 1 in the width direction Y, corresponding to the coverage of the electrode break zone 32 of the battery cell 3. This avoids the conductive layer 2 being too large or too small, causing it to deviate from the break zone. That is, even after the single-sided and double-sided junction zone of the cathode breaks, it can still conduct electricity through the conductive layer 2 in this embodiment. In this embodiment, the width W of the adhesive tape body 1 is 1.8π * battery cell thickness, the width W1 of the conductive layer 2 is 0.55π * battery cell thickness, and the thickness t1 of the conductive layer 2 is 5μm.

[0066] The other structures are the same as in Example 1, and will not be described again here.

[0067] Example 6

[0068] The difference from Example 5 is that the width W of the adhesive tape body 1 is 1.8π * cell thickness, the width W1 of the conductive layer 2 is 0.45π * cell thickness, and the thickness t1 of the conductive layer 2 is 5μm.

[0069] The other structures are the same as in Example 5, and will not be described again here.

[0070] Example 7

[0071] Unlike Example 1: See Figures 5-6As shown, the conductive layer 2 in this embodiment includes multiple conductive blocks 21, which are spaced apart on the surface of the adhesive tape body 1. The conductive blocks 21 cover 45% to 55% of the adhesive tape body 1 to avoid the coverage area being too large or too small, which would cause the conductive layer 2 to deviate from the broken area. The width L1 of the conductive blocks 21 satisfies the relationship: L1 = 0.08 to 0.2L, where L is the length of the adhesive tape body 1. For example, the width L1 of the conductive blocks 21 can be 0.08L, 0.09L, 0.11L, 0.12L, 0.13L, 0.14L, 0.15L, 0.16L, 0.17L, 0.18L, 0.19L, or 0.2L, etc. The multiple conductive blocks 21 are distributed along the surface of the adhesive tape body 1. The adhesive tape is arranged at equal intervals along its length X. The distance L2 between two adjacent conductive blocks 21 satisfies the relationship: L2 = 0.08 ~ 0.2L. For example, the distance L2 between two adjacent conductive blocks 21 is 0.08L, 0.09L, 0.11L, 0.12L, 0.13L, 0.14L, 0.15L, 0.16L, 0.17L, 0.18L, 0.19L, or 0.2L, etc. Compared with the structure of Embodiment 1, it can save material of conductive layer 2. Moreover, the gap between adjacent conductive blocks 21 also forms an adhesive area, which helps to increase the area of ​​the adhesive area of ​​the adhesive tape, thereby improving the overall adhesive performance of the adhesive tape and preventing the adhesive tape from falling off the battery core. The width L1 of the conductive block 21 and the distance L2 between two adjacent conductive blocks 21 can be the same or different, which is not limited here. The shape of the conductive block 21 is preferably square, and the shapes of each conductive block 21 are roughly the same. In some embodiments, the conductive block 21 can also be other regular or irregular shapes, and the shapes of each conductive block 21 can also be different, which is not limited here. In this embodiment, the width W of the adhesive tape body 1 is 1.8π * battery cell thickness, the width W1 of the conductive layer 2 is 1.0π * battery cell thickness, the thickness t1 of the conductive layer 2 is 5μm, and the distance L2 between two adjacent conductive blocks 21 is 0.1 * L.

[0072] The other structures are the same as in Example 1, and will not be described again here.

[0073] Example 8

[0074] The difference from Example 7 is that the width W of the adhesive tape body 1 is 1.8π * battery cell thickness, the width W1 of the conductive layer 2 is 1.0π * battery cell thickness, the thickness t1 of the conductive layer 2 is 5μm, and the distance L2 between two adjacent conductive blocks 21 is 0.2 * L.

[0075] The other structures are the same as in Example 7, and will not be described again here.

[0076] Example 9

[0077] Unlike Example 7: See Figures 7-8As shown, in this embodiment, multiple conductive blocks 21 are arranged at equal intervals along the length X of the adhesive paper. The included angle θ formed between the conductive block 21 and the edge of the conductive layer 2 is 40° to 50°. In this embodiment, the edge of the conductive layer 2 can be understood as the edge of the long side of the conductive layer 2. For example, the included angle θ formed between the conductive block 21 and the edge of the conductive layer 2 is 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49° or 50°, etc. The tilt angle θ can be adjusted according to the actual structure of the adhesive paper, and is not limited here. The distance L2 between two adjacent conductive blocks 21 satisfies the relationship: L2 = 0.08~0.2L. The distance L2 between two adjacent conductive blocks 21 can be 0.08L, 0.09L, 0.11L, 0.12L, 0.13L, 0.14L, 0.15L, 0.16L, 0.17L, 0.18L, 0.19L, or 0.2L, etc. This distance can also form an adhesive area between adjacent conductive blocks 21, helping to increase the area of ​​the adhesive tape's adhesive region, thereby improving the overall adhesive performance of the adhesive tape and preventing the adhesive tape from detaching from the battery cell. The conductive blocks 21 have approximately the same shape. In some embodiments, the shape of the conductive blocks 21 is preferably a parallelogram, and the shapes are generally similar. In some embodiments, the conductive blocks 21 can also have other regular or irregular shapes, and the shapes of each conductive block 21 can also be different; this is not limited here. In this embodiment, the width W of the adhesive tape body 1 is 1.8π * battery cell thickness, the width W1 of the conductive layer 2 is 1.0π * battery cell thickness, the thickness t1 of the conductive layer 2 is 5μm, the distance L2 between two adjacent conductive blocks 21 is 0.2 * L, and the included angle θ formed between the conductive block 21 and the edge of the conductive layer (2) is 42°.

[0078] The other structures are the same as in Example 7, and will not be described again here.

[0079] Example 10

[0080] The difference from Example 9 is that the width W of the adhesive tape body 1 is 1.8π * the thickness of the battery cell, the width W1 of the conductive layer 2 is 1.0π * the thickness of the battery cell, the thickness t1 of the conductive layer 2 is 5μm, the distance L2 between two adjacent conductive blocks 21 is 0.2 * L, and the included angle θ formed between the conductive block 21 and the edge of the conductive layer (2) is 48°.

[0081] The other structures are the same as in Example 9, and will not be described again here.

[0082] Example 11

[0083] Unlike Embodiment 1, in this embodiment, the conductive layer 2 is fixed to the surface of the first or second side by adhesive bonding. Specifically, an adhesive layer is provided between the conductive layer 2 and the adhesive paper body 1, which fixes the conductive layer 2 to the surface of the first or second side. This also covers the electrode breakage area 32 of the battery cell 3, ensuring that after the single- or double-sided junction area of ​​the cathode breaks, it can still conduct electricity through the conductive layer 2. This solves the problem that the battery cell cannot be charged and discharged after the outer cathode breaks, and avoids a sudden drop in battery cell capacity.

[0084] The other structures are the same as in Example 1, and will not be described again here.

[0085] Example 12

[0086] Unlike Embodiment 1, the surface of the first or second side of this embodiment is provided with a groove. The groove can be formed by laser grooving or other processes. The conductive layer 2 is fixed to the groove by electroplating, which helps to reduce the overall thickness of the adhesive paper, thereby reducing the impact of the adhesive paper on the overall thickness of the battery cell. It can also cover the electrode breakage area 32 of the battery cell 3, ensuring that after the single- and double-sided junction area of ​​the cathode breaks, it can conduct electricity through the conductive layer 2, solving the problem that the battery cell cannot be charged and discharged after the outer ring cathode breaks, and avoiding the sudden drop in battery cell capacity.

[0087] The other structures are the same as in Example 1, and will not be described again here.

[0088] Example 13

[0089] Unlike Embodiment 1, this embodiment has a groove on the surface of the first or second side, and the conductive layer 2 is fixed to the groove by adhesive bonding. Specifically, an adhesive layer is provided between the conductive layer 2 and the bottom of the groove, embedding the conductive layer 2 into the first or second side. This also helps to reduce the overall thickness of the adhesive tape and its impact on the overall thickness of the battery cell. At the same time, it can cover the electrode breakage area 32 of the battery cell 3, ensuring that after the single- or double-sided junction area of ​​the cathode breaks, it can still conduct electricity through the conductive layer 2. This solves the problem that the battery cell cannot be charged and discharged after the outer cathode breaks, and avoids a sudden drop in battery cell capacity.

[0090] The other structures are the same as in Example 1, and will not be described again here.

[0091] Comparative Example 1

[0092] In this embodiment, the adhesive tape surface has no conductive layer, and the width of the adhesive tape body 1 is 1.8π * the cell thickness.

[0093] The adhesive tapes obtained in Examples 1-10 and Comparative Example 1 were applied to lithium-ion batteries, and capacity changes after cathode strip breakage were tested. The experimental results are shown in Table 1 below.

[0094] Table 1. Test results of capacity change after cathode breakage in lithium-ion batteries

[0095]

[0096]

[0097] As can be seen from Table 1 above, the capacity change test and capacity reduction rate of the batteries prepared in Examples 1 to 10 after cathode breakage are all better than those of Comparative Example 1. This indicates that by covering the entire corner area 31 of the cell 3 with the conductive layer 2 on the adhesive paper, the battery can conduct electricity through the conductive layer 2 on the adhesive paper body 1 after the cathode breaks in the corner area of ​​the outer ring of the cell, without changing the structure of the cell. This solves the problem of the inability to charge and discharge after the cathode breaks in the outer ring of the cell and avoids the sudden drop in cell capacity.

[0098] battery cells

[0099] This utility model includes the adhesive paper structure of Examples 1 to 13.

[0100] Specifically, it includes a battery cell 3 and an adhesive tape structure as described above. The battery cell 3 has a corner area 31 or an electrode break area 32, and the conductive layer 2 covers the corner area 31 or the electrode break area 32.

[0101] Cell 3 includes a first electrode, a separator, and a second electrode, which are sequentially wound to form a core. The battery is encapsulated in a casing or aluminum-plastic film. The first and second electrodes are respectively provided with tabs, the positions of which correspond to the positive and negative electrodes on the casing or cover. To prevent short circuits between the positive and negative electrodes, a separator is provided between every two adjacent electrodes, achieving electrical isolation between electrodes of opposite polarity. The first electrode can be a positive electrode or a cathode, and the second electrode can be a negative electrode or an anode; alternatively, the first electrode can be a negative electrode or an anode, and the second electrode can be a positive electrode or a cathode; no restrictions are placed here.

[0102] See Figure 9 As shown, the outermost ring of cell 3 is the cathode. The tail section of the cathode is coated with active material on one side, while the middle section of the cathode is coated with active material on both sides. The junction area between the single and double sides of the cathode, i.e., the electrode breakage area 32, has bevel stress, which is prone to breakage during battery cycling. Therefore, the conductive layer 2 of the adhesive tape is used to cover the electrode breakage area 32 of cell 3 to ensure that after the electrode breakage area of ​​the single and double sides of the cathode, it can conduct electricity through the conductive layer 2, solving the problem that the outer ring cathode cannot be charged and discharged after the electrode breakage area, and avoiding the sudden drop in cell capacity. In addition, the area on the adhesive tape body 1 other than the conductive layer 2 is the bonding area, which covers the flat area 33 of cell 3, playing a bonding role, ensuring the bonding strength of the adhesive tape, and preventing the adhesive tape from falling off during use.

[0103] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this utility model are within the protection scope of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model.

Claims

1. A type of adhesive tape structure, characterized in that, It includes an adhesive tape body (1) and a conductive layer (2); The adhesive tape body (1) has a first surface and a second surface that are opposite each other in the thickness direction (Z); The conductive layer (2) is disposed on the first surface or the second surface. The conductive layer (2) extends along the width direction (Y) of the adhesive paper body (1) and is used to cover the corner area (31) or electrode break area (32) of the battery cell (3).

2. The adhesive tape structure as described in claim 1, characterized in that: The conductive layer (2) is fixed to the surface of the first or second surface by electroplating or bonding; or The surface of the first or second surface is provided with a groove, and the conductive layer (2) is fixed to the groove by electroplating or bonding.

3. The adhesive tape structure as described in claim 2, characterized in that: The ratio of the length L of the adhesive tape body (1) to the length of the battery cell is 1.01 to 1.05, and the ratio of the width W of the adhesive tape body (1) to the thickness of the battery cell is 1.5 to 2π.

4. The adhesive tape structure as described in claim 3, characterized in that: The conductive layer (2) is centrally disposed along the width direction (Y) of the adhesive tape body (1), and the ratio of the width W1 of the conductive layer (2) to the thickness of the battery cell is 0.9 to 1.1π; or The conductive layer (2) is disposed on one side edge of the adhesive tape body (1) in the width direction (Y). The ratio of the width W1 of the conductive layer (2) to the thickness of the battery cell is 0.45 to 0.55π. The farthest distance W2 between the conductive layer (2) and one side edge of the adhesive tape body (1) satisfies the relationship: W2 = 0.45 to 0.55π.

5. The adhesive tape structure as described in claim 3 or 4, characterized in that: The conductive layer (2) includes a plurality of conductive blocks (21), which are spaced apart on the surface of the adhesive tape body (1). The width L1 of the conductive block (21) satisfies the following relationship: L1 = 0.08 to 0.2L. The proportion of the conductive block (21) covering the adhesive tape body (1) is 45% to 55%.

6. The adhesive tape structure as described in claim 5, characterized in that: Multiple conductive blocks (21) are arranged at equal intervals along the length direction (X) of the adhesive paper, and the distance L2 between two adjacent conductive blocks (21) satisfies the relationship: L2 = 0.08 ~ 0.2L.

7. The adhesive tape structure as described in claim 5, characterized in that: Multiple conductive blocks (21) are inclined at equal intervals along the length direction (X) of the adhesive paper. The included angle θ formed between the conductive block (21) and the edge of the conductive layer (2) is 40° to 50°. The distance L2 between two adjacent conductive blocks (21) satisfies the relationship: L2 = 0.08 to 0.2L.

8. The adhesive tape structure as described in claim 3 or 4, characterized in that: The thickness t1 of the conductive layer (2) is 3 to 5 μm, and the sum of the thicknesses t of the conductive layer (2) and the adhesive paper body (1) is 10 to 18 μm.

9. The adhesive tape structure as described in claim 1, characterized in that: The adhesive tape body (1) is made of polypropylene, polyethylene terephthalate or polyimide, and the conductive layer (2) is made of aluminum, nickel or stainless steel.

10. A battery cell, characterized in that: The battery cell (3) includes a cell (3) and a paper structure as described in any one of claims 1-9, wherein the cell (3) has a corner region (31) or an electrode break region (32), and the conductive layer (2) covers the corner region (31) or the electrode break region (32).

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