Battery cell structure

Abstract

The utility model relates to a battery cell structure. The battery cell structure comprises a positive plate, a negative plate, an isolating membrane, a packaging shell and tab structures, wherein the tab structures are respectively arranged on the positive plate and the negative plate; the tab structure comprises a tab body and tab glue; the tab body is provided with a connecting part, and the connecting part is opposite to the sealing edge of the packaging shell; the tab glue is arranged on the tab body and wraps the periphery of the connecting part, and the packaging shell is hermetically connected with the connecting part through the tab glue; one side of the tab glue and one side of the isolating membrane in the width direction are overlapped in the thickness direction of the battery cell structure; the tab glue is provided with a notch, an opening on one side of the notch faces the edge of one side of the isolating membrane in the width direction, and an opening on the other side faces the edge of one side of the isolating membrane close to the width direction of the packaging shell. According to the scheme provided by the invention, interference between the tab glue and the isolating membrane can be prevented.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell structure. Background Art

[0002] The battery cell of a lithium-ion battery usually has a pole piece, a pole ear and an isolation membrane. The pole ear is connected to the pole piece, and the pole ear and the isolation membrane overlap in the length direction of the battery cell. The pole ear is provided with a pole ear glue, which is used to connect the packaging shell to the part corresponding to the top seal of the battery cell, thereby realizing a sealed connection between the packaging shell and the pole ear through the pole ear glue.

[0003] In the related technology, the distance between the tab glue and the edge of the isolation membrane is relatively close, and the tab glue and the isolation membrane located on the inner circle are prone to interference, which will cause the center distance of the tab to deviate from the design value, and there is a risk that the isolation membrane will be scratched by the tab glue, causing a short circuit inside the battery cell. Utility Model Content

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a battery cell structure that can prevent the tab glue from interfering with the isolation membrane.

[0005] The present application provides a tab structure, comprising: a positive electrode sheet, a negative electrode sheet, a separator, a packaging shell and a tab structure;

[0006] The positive electrode sheet, the separator and the negative electrode sheet are sequentially stacked and wound in the packaging shell, and the positive electrode sheet and the negative electrode sheet are respectively provided with the tab structure;

[0007] The tab structure includes a tab body and tab glue; one end of the tab body extends into the packaging shell, and the other end of the tab body extends out of the packaging shell, and a connecting portion is provided on the tab body, and the connecting portion is opposite to the sealed edge of the packaging shell; the tab glue is provided on the tab body and wraps around the connecting portion, and the packaging shell is sealed and connected to the connecting portion through the tab glue;

[0008] One side of the tab glue overlaps with one side of the isolation membrane in the width direction in the thickness direction of the battery cell structure; a notch is provided on the tab glue, one side of the notch opening faces one edge of the isolation membrane in the width direction, and the other side opening faces one edge of the isolation membrane close to the width direction of the packaging shell.

[0009] Furthermore, the tab glue includes a first film and a second film;

[0010] The first film is provided on one side of the connecting portion, and the second film is provided on the other side of the connecting portion; one end of the first film is connected to one end of the second film, and the other end of the first film is connected to the other end of the second film;

[0011] The notches are provided on the first film and the second film.

[0012] Furthermore, a dimension of the notch along the width direction of the battery cell structure is d1, 1mm≤d1≤5mm.

[0013] Furthermore, the distance between the tab body and the notch is d2, 0.1 mm ≤ d2 < d1.

[0014] Furthermore, a dimension of the notch along the height direction of the battery cell structure is h1, 0.2 mm ≤ h1 ≤ 3 mm.

[0015] Furthermore, the notch is a right-angled notch, a circular arc notch or an elliptical arc notch.

[0016] Furthermore, the thickness of the tab glue is 0.03mm-0.5mm.

[0017] Furthermore, the thickness of the tab glue is 0.1mm-0.5mm.

[0018] Furthermore, the positive electrode sheet has an aluminum foil current collector, and the negative electrode sheet has a copper foil current collector.

[0019] Furthermore, the tab body on the positive electrode sheet is made of aluminum sheet, and the tab body on the negative electrode sheet is made of nickel sheet or copper-plated nickel material.

[0020] The technical solution provided in the present application may include the following beneficial effects: one side of the tab glue overlaps with one side of the isolation membrane in the width direction in the thickness direction of the battery cell structure, and a notch is set in the tab glue, with one side of the notch opening facing one edge of the isolation membrane in the width direction, and the other side opening facing one edge of the isolation membrane close to the width direction of the packaging shell, thereby preventing interference between the tab glue and the isolation membrane in the overlapping part in the thickness direction of the battery cell structure.

[0021] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0023] Figure 1 It is a structural schematic diagram of a battery cell structure shown in the related art;

[0024] Figure 2 Schematic diagram of the structure of the battery cell shown in the embodiment of the present application;

[0025] Figure 3 Schematic diagram of the structure of the tab structure shown in the embodiment of the present application;

[0026] Figure 4 1 is a schematic structural diagram of a tab structure assembly for cutting into two tab structures, as shown in an embodiment of the present application;

[0027] Figure 5 yes Figure 4 Side view of;

[0028] Figure 6 yes Figure 4 Top view of .

[0029] Reference numerals:

[0030] 1-positive electrode sheet, 2-negative electrode sheet, 3-separator, 4-positive electrode ear, 5-negative electrode ear, 6'-electrode ear glue, 6-electrode ear glue, 7-electrode body, 8-notch. DETAILED DESCRIPTION

[0031] The following describes embodiments of the present application in more detail with reference to the accompanying drawings. Although the accompanying drawings illustrate embodiments of the present application, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0032] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0034] Unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," and the like should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0035] like Figure 1 As shown, in the related art, the cell structure of the lithium-ion battery includes a positive electrode sheet 1, a negative electrode sheet 2, a separator 3, a positive electrode ear 4 and a negative electrode ear 5, and the positive electrode ear 4 and the negative electrode ear 5 are respectively provided with an ear glue 6'. The positive electrode sheet 1, the separator 3 and the negative electrode sheet 2 are stacked and wound in sequence, and the separator 3 is located between the positive electrode sheet 1 and the negative electrode sheet 2. The positive electrode ear 4 is connected to the positive electrode sheet 1, and the negative electrode ear 5 is connected to the negative electrode sheet 2. The ear glue 6' is mainly used for sealing the ear and the aluminum-plastic film of the packaging shell. The distance between the tab glue 6' on the negative tab 5 and the edge of the innermost circle of the isolation membrane 3 in the width direction of the battery cell is D1, and the distance between the tab glue 6' on the positive tab 4 and the edge of the innermost circle of the isolation membrane 3 in the width direction of the battery cell is D2. The distance between the tab glue 6' and the edge of the isolation membrane 3 in the width direction of the battery cell is close, that is, D1 and D2 are small. The tab glue 6' and the edge of the isolation membrane 3 located in the innermost circle in the width direction of the battery cell are prone to interference, which will cause the center distance between the two tabs to deviate from the design value, and there is a risk that the isolation membrane 3 will be scratched by the tab glue 6', causing an internal short circuit in the battery cell.

[0036] In response to the above problems, an embodiment of the present application provides a battery cell structure that can prevent the tab glue from interfering with the isolation film 3 .

[0037] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0038] like Figure 2 As shown, the embodiment of the present application provides a battery cell structure, including a positive electrode sheet 1, a negative electrode sheet 2, a separator 3, a packaging case, and a tab structure. The positive electrode sheet 1, the separator 3, and the negative electrode sheet 2 are sequentially stacked and wound in the packaging case, and the positive electrode sheet 1 and the negative electrode sheet 2 are each provided with a tab structure. The tab structure provided on the positive electrode sheet 1 is a positive tab 4, and the tab structure provided on the negative electrode sheet 2 is a negative tab 5.

[0039] like Figure 3As shown, the tab structure includes a tab body 7 and a tab glue 6. One end of the tab body 7 extends into the packaging shell, and the other end of the tab body 7 extends out of the packaging shell. A connecting portion is provided on the tab body 7, and the connecting portion is opposite to the sealed edge of the packaging shell; the tab glue 6 is provided on the tab body 7 and wraps around the connecting portion. The packaging shell is sealed and connected to the connecting portion through the tab glue 6.

[0040] like Figure 2 As shown, one side of the tab glue 6 overlaps with one side of the isolation membrane 3 in the width direction in the thickness direction of the battery cell structure; a notch 8 is provided on the tab glue 6, and one side of the notch 8 opens to one edge of the isolation membrane 3 in the width direction, and the other side opens to one edge of the isolation membrane 3 close to the width direction of the packaging shell.

[0041] By providing a notch 8 in the tab glue 6, one side of the notch 8 faces one edge of the separator 3 in the width direction, and the other side faces one edge of the separator 3 close to the width direction of the package, thereby preventing interference between the tab glue 6 and the separator 3 at the overlapping portion in the thickness direction of the battery cell structure. The package can be an aluminum-plastic film.

[0042] like Figures 4 to 6 As shown, the embodiment of the present application provides a tab structure combination for cutting into two tab structures, a plurality of tab glues 6 are arranged on the tab body 7, and the tab body 7 is in a state of not being cut. When the tab is welded, Figures 4 to 6 The tab structure shown is cut so that the length of the cut tab body 7 is adapted to the battery cell, and each section of the tab body 7 is provided with a tab glue 6 .

[0043] In some embodiments, the tab glue 6 includes a first film and a second film; the first film is arranged on one side of the connecting part, and the second film is arranged on the other side of the connecting part; one end of the first film is connected to one end of the second film, and the other end of the first film is connected to the other end of the second film; the notch 8 is arranged on the first film and the second film.

[0044] In some embodiments, as Figure 3 As shown, the dimension of the notch 8 along the width direction of the cell structure is d1, 1mm≤d1≤5mm. The value of d1 is required not to exceed the cell body in the width direction of the cell, and d1 generally does not exceed half of the cell thickness. Generally, 1mm≤d1≤5mm.

[0045] In some embodiments, as Figure 3 As shown, the distance between the tab body 7 and the notch 8 is d2, 0.1mm≤d2<d1. d2 cannot be too small to ensure the insulation performance when the tab glue 6 wraps the tab body 7.

[0046] In some embodiments, the dimension of the gap 8 along the height direction of the cell structure is h1, and 0.2 ≤ h1 ≤ 3 mm. The lower limit of h1 can be determined based on the degree of interference between the tab glue 6 and the separator 3 in the actual cell design. The upper limit of h1 must ensure that the wide portion of the tab glue 6, i.e., h2, can completely cover the cell top seal area. Generally, 0.2 mm ≤ h1 ≤ 3 mm.

[0047] In some embodiments, the notch 8 is a right-angled notch, an arc notch or an elliptical notch. Figure 3 As shown, the notch 8 in the figure is a right-angled notch, and the shape of the notch 8 is rectangular. The tab glue 6 is also rectangular when the notch 8 is not provided, and the notch 8 cuts off a corner of the rectangle of the tab glue 6.

[0048] In some embodiments, the thickness of the tab adhesive 6 is 0.03-0.5 mm. The tab adhesive 6 can be a hot melt adhesive made of a polymer material that melts and bonds when heated. Preferably, the thickness of the tab adhesive 6 is 0.1 mm-0.5 mm.

[0049] In some embodiments, the positive electrode sheet 1 has an aluminum foil current collector, and the negative electrode sheet 2 has a copper foil current collector. One end of the positive electrode tab 4 is welded to the aluminum foil current collector, and one end of the negative electrode tab 5 is welded to the copper foil current collector.

[0050] In some embodiments, the tab body 7 on the positive electrode sheet 1 is made of an aluminum sheet, and the tab body 7 on the negative electrode sheet 2 is made of a nickel sheet or a copper-plated nickel material.

[0051] In summary, the embodiment of the present application provides a battery cell structure, which is provided with a pole ear structure, and the pole ear structure has a pole ear body 7 and a pole ear glue 6, and one side of the pole ear glue 6 overlaps with the side in the width direction of the isolation membrane 3 in the thickness direction of the battery cell structure; a notch 8 is provided on the pole ear glue 6, and one side of the notch 8 opens to one side edge in the width direction of the isolation membrane 3, and the other side opens to one side edge of the isolation membrane 3 close to the width direction of the packaging shell, so that even when the distance between the pole ear glue 6 and the edge of the isolation membrane 3 is close, the pole ear glue 6 can maintain a certain gap with the isolation membrane 3 through the notch 8 to prevent interference between the pole ear glue 6 and the isolation membrane 3.

[0052] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for this application. In addition, it is understood that the steps in the method of the embodiment of the present application can be adjusted in sequence, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0053] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A battery cell structure, characterized in that: include: A positive electrode sheet (1), a negative electrode sheet (2), a separator (3), a packaging shell and a tab structure; The positive electrode sheet (1), the separator (3) and the negative electrode sheet (2) are sequentially stacked and wound in the packaging shell, and the positive electrode sheet (1) and the negative electrode sheet (2) are respectively provided with the tab structure; The tab structure comprises a tab body (7) and a tab glue (6); one end of the tab body (7) extends into the packaging shell, and the other end of the tab body (7) extends out of the packaging shell, and a connecting portion is provided on the tab body (7), and the connecting portion is opposite to the sealing edge of the packaging shell; the tab glue (6) is provided on the tab body (7) and wraps around the connecting portion, and the packaging shell is sealed and connected to the connecting portion through the tab glue (6); One side of the tab glue (6) overlaps with one side of the isolation membrane (3) in the width direction in the thickness direction of the battery core structure; a notch (8) is provided on the tab glue (6), one side of the notch (8) opening faces one side edge of the isolation membrane (3) in the width direction, and the other side opening faces one side edge of the isolation membrane (3) close to the width direction of the packaging shell.

2. The battery cell structure according to claim 1, wherein: The tab glue (6) comprises a first glue sheet and a second glue sheet; The first film is provided on one side of the connecting portion, and the second film is provided on the other side of the connecting portion; one end of the first film is connected to one end of the second film, and the other end of the first film is connected to the other end of the second film; The notch (8) is provided on the first film and the second film.

3. The battery cell structure according to claim 1, wherein: The dimension of the notch (8) along the width direction of the battery core structure is d1, 1mm≤d1≤5mm.

4. The battery cell structure according to claim 3, wherein: The distance between the tab body (7) and the notch (8) is d2, 0.1 mm ≤ d2 < d1.

5. The battery cell structure according to claim 1, wherein: The dimension of the notch (8) along the height direction of the battery core structure is h1, 0.2mm≤h1≤3mm.

6. The battery cell structure according to claim 1, wherein: The notch (8) is a right-angled notch, a circular arc notch or an elliptical arc notch.

7. The battery cell structure according to claim 1, wherein: The thickness of the tab glue (6) is 0.03mm-0.5mm.

8. The battery cell structure according to claim 7, characterized in that: The thickness of the tab glue (6) is 0.1mm-0.5mm.

9. The battery cell structure according to claim 1, wherein: The positive electrode sheet (1) has an aluminum foil current collector, and the negative electrode sheet (2) has a copper foil current collector.

10. The battery cell structure according to claim 8, characterized in that: The tab body (7) on the positive electrode sheet (1) is made of an aluminum sheet, and the tab body (7) on the negative electrode sheet (2) is made of a nickel sheet or a copper-plated nickel material.

Images