Tab and soft package battery
By setting a thin structure on the end surface of the metal sheet of the electrode ear to form a smooth adhesive surface with the metal sheet, the problems of poor packaging reliability of the electrode ear and the electrolyte leakage are solved, and the packaging strength and flatness are improved.
Patent Information
- Application Number
- CN202422061796.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-23
AI Technical Summary
In the prior art, the thickness gap between the connection between the electrode metal sheet and the electrode glue is too large, resulting in poor packaging reliability and increasing the risk of electrolyte leakage.
A thin structure is provided on the end surfaces of both sides of the extreme ear metal sheet. The thickness of the thin structure decreases along the main body of the metal sheet toward the end portion. The extreme ear glue penetrates into the end surface of the thin structure in a molten state to form a smooth adhesive surface.
The packaging strength of the extreme ear metal sheet and extreme ear glue is improved, the protrusion of the overflow rubber is reduced, the edge sealing flatness is improved, and the risk of extreme ear sealing cracking and electrolyte leakage is reduced.
Smart Images
Figure CN223039090U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of battery technology, and in particular to a tab and a soft-pack battery. Background Art
[0002] New energy battery technology is constantly improving, and the tab technology is one of the keys to improving battery performance. Tabs are the conductive lead-out components of the positive and negative electrodes of the battery. Tabs lead the current from the active material layer of the battery cell and are the transmission channel for the current when the battery is charged and discharged.
[0003] In the prior art, the tabs of the battery cells of soft-pack batteries are usually made by hot-pressing composite metal sheets and tab glue. With the rapid development of the new energy vehicle industry, the demand for the capacity growth of new energy batteries is becoming increasingly urgent, and the current-carrying capacity of the tabs also needs to increase accordingly, and the production needs need to be met by increasing the thickness of the tabs. When the thickness difference between the end face where the tab metal sheet and the tab glue meet is greater than the thickness of the tab glue itself, the reliability of the tab glue packaging will deteriorate, increasing the risk of electrolyte leakage. Utility Model Content
[0004] The purpose of the present application is to provide a tab and a soft-pack battery, which can improve the packaging strength of the tab end face joint of the soft-pack battery cell and reduce the risk of tab edge cracking and electrolyte leakage.
[0005] To achieve the above-mentioned purpose, the first aspect of the embodiment of the present disclosure provides a tab, which includes: a metal sheet 1 and a tab glue 2;
[0006] The metal sheet 1 includes a thinning structure 3, which is arranged at the ends of both sides of the main body of the metal sheet, and the thickness of the thinning structure 3 decreases along the main body of the metal sheet 1 toward the ends of the metal sheet;
[0007] The ear glue 2 is used to cover the metal sheet 1 .
[0008] In some embodiments, the thickness of the metal sheet 1 is greater than or equal to 0.2 mm.
[0009] In some embodiments, the tab glue 2 in a molten state penetrates into the end surface of the thinned structure 3 so that the tab glue and the end surface of the thinned structure form a smooth occlusal surface.
[0010] In some embodiments, the upper and lower surfaces of the thinned structure 3 are both inclined surfaces.
[0011] In some embodiments, the angle between the two inclined surfaces formed by the thinning structure 3 is 30 to 40 degrees.
[0012] In some embodiments, the cross section of the thinned structure 3 is triangular.
[0013] In some embodiments, when the thickness of the metal sheet 1 increases, the angle between the two inclined planes formed by the thinning structure increases accordingly.
[0014] In some embodiments, the width of the thinning structure 3 is 2.0 to 3.0 millimeters.
[0015] In some embodiments, the upper and lower surfaces of the thinning structure 3 are symmetric structures.
[0016] In a second aspect of the embodiments of the present disclosure, a soft-pack battery is provided, including a battery cell and the above-mentioned tab, and the tab is used to connect the battery cell and an electrical appliance.
[0017] In the embodiments of the present disclosure, by providing a thinning structure at the end faces on both sides of the metal sheet of the tab, during the hot pressing and compounding process of the tab and the packaging bag, the tab glue in a molten state penetrates to the end faces of the thinning structure, and the gradually decreasing thickness difference enables the tab glue and the end faces of the metal sheet thinning structure to form a relatively smooth bonding surface. On the one hand, it can increase the packaging strength between the end of the metal sheet of the tab and the tab glue, and on the other hand, it can reduce the convex phenomenon of glue overflow and accumulation, improve the flatness of the tab edge sealing, and at the same time reduce the risks of tab edge cracking and electrolyte leakage. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0019] Figure 1 is a schematic structural diagram of the tab disclosed in the embodiments of the present disclosure;
[0020] Figure 2 is a schematic cross-sectional exploded structural diagram of the tab disclosed in the embodiments of the present disclosure.
[0021] DESCRIPTION OF THE REFERENCE NUMERALS
[0022] 1. Metal sheet
[0023] 2. Tab glue
[0024] 3. Thinning structure DETAILED DESCRIPTION OF THE EMBODIMENTS
[0025] The following will further describe in detail the embodiments of the present disclosure in conjunction with the drawings and embodiments. The detailed description and drawings of the following embodiments are used to exemplarily illustrate the principles of the present disclosure, but cannot be used to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms, not limited to the specific embodiments disclosed herein, but including all technical solutions falling within the scope of the claims.
[0026] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the compositions of materials, numerical expressions and values set forth in these embodiments should be construed as merely exemplary, rather than as limitations.
[0027] It should be noted that in the description of the present disclosure, unless otherwise specified, the meaning of "a plurality" is greater than or equal to two; the orientation or positional relationships indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are only for the convenience of describing the present disclosure 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 thus cannot be construed as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0028] In addition, the "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different parts. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range. Words such as "including" or "comprising" mean that the elements before this word cover the elements listed after this word, and do not exclude the possibility of also covering other elements.
[0029] It should also be noted that in the description of the present disclosure, unless otherwise clearly defined and limited, the terms "mounted", "connected" and "coupled" 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 directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances. When it is described that a specific device is located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device.
[0030] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as those, should be construed to have meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such here.
[0031] Techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods and devices should be regarded as part of the specification.
[0032] Example
[0033] Figure 1 Schematic diagram of the structure of the tab disclosed in the embodiment of the present disclosure. Figure 1 As shown, an embodiment of the present disclosure provides a tab, which includes: a metal sheet 1 and a tab glue 2.
[0034] Among them, the tab is an important component of lithium-ion battery components. The tab is a metal conductor that leads the positive and negative electrodes from the battery cell. It is equivalent to the "ears" of the positive and negative electrodes of the battery and is used as a contact point during charging and discharging. The positive electrode of the battery usually uses a tab made of aluminum material, while the negative electrode uses a tab made of nickel material. In some cases, the negative electrode may also use a tab made of copper-plated nickel material.
[0035] The tabs on the market are generally made of metal sheets and tab glue by hot pressing. During the battery packaging process, the tab glue is heated and hot-melt-sealed with the aluminum-plastic film to form an airtight and liquid-tight package to prevent electrolyte leakage and ensure the sealing of the battery.
[0036] The inventors of the present application discovered during the research process that when soft-pack batteries are packaged at the tabs, uneven pressure, uneven thickness of the tab glue and the PP layer structure on the inner side of the packaging bag, uneven surface, etc. often lead to uneven glue overflow strips, resulting in a large amount of glue overflow in some places, and the overflow glue blocks harden after cooling.
[0037] During the later use of the battery cell, the packaging will undergo varying degrees of deformation, and stress concentration will occur at the large overflow block, which is prone to tearing. If it occurs on the inside of the seal, the risk of electrolyte infiltration and contact with the middle metal layer of the packaging bag and electrolyte leakage will increase.
[0038] Therefore, in order to solve the problems of cracking of the edge sealing of the pole tab of the soft-pack battery cell and leakage of electrolyte from the end face of the pole tab, the inventor of the present application proposes to perform upper and lower thinning treatment on both sides of the pole tab metal sheet at the glue-coated part during the production process of the pole tab, so as to reduce the end face drop where the pole tab metal sheet and the pole tab glue are connected, thereby improving the packaging strength at the connection between the end faces of the pole tab of the soft-pack battery cell and reducing the risk of cracking of the edge sealing of the pole tab and leakage of electrolyte.
[0039] Specifically, the metal sheet 1 includes a thinning structure 3, which is arranged at the ends of both sides of the main body of the metal sheet, and the thickness of the thinning structure 3 decreases from the main body of the metal sheet to the ends of the metal sheet.
[0040] The ear glue 2 is used to cover the metal sheet 1 .
[0041] Specifically, the tab glue is the insulated part on the tab, which is used to prevent the metal strip from short-circuiting with other conductive parts of the battery or the aluminum-plastic film, ensuring the safety of the battery. The tab glue usually consists of multiple layers of materials, including a middle skeleton layer and modified PP layers on both sides. Some high-end tab glues distinguish between the modified PP materials on the two surfaces, with one side being metal-adhesive modified PP and the other side being plastic-adhesive modified PP to pursue higher bonding strength.
[0042] In some embodiments, both the upper and lower surfaces of the thinning structure 3 are inclined planes. That is, during the production of the tab, the end portions on both sides of the main body of the metal sheet 1 are thinned on both the upper and lower surfaces to form a thinning structure with inclined planes on both the upper and lower surfaces.
[0043] Figure 2 is a schematic cross-sectional exploded view of the tab disclosed in the embodiments of the present disclosure. Referring to Figure 2 Figure, the tab glue 2 is coated on the metal sheet 1, and thinning structures 3 are provided at both end portions on both sides of the metal sheet 1 coated with the tab glue 2. Moreover, the thinning structure 3 is a double-sided thinning structure, and the cross-section of the thinning structure 3 is triangular.
[0044] The thickness of the thinning structure 3 gradually decreases from the middle of the metal sheet 1 towards the end of the metal sheet 1, and it has a symmetrical inclined plane shape on the upper and lower surfaces. The included angle between the two inclined planes formed by the thinning structure 3 is about 30 to 40 degrees, and the width of the thinning structure is about 2.0 to 3.0 mm.
[0045] It should be noted that as the capacity of the battery cell increases, the current-carrying capacity that the tab needs to withstand also increases. It is necessary to increase the thickness of the tab to meet the production requirements, that is, to increase the thickness of the metal sheet. Currently, the thickness of the tab is generally 0.2 to 0.5 mm. Any thinning structure that can achieve a large-end face drop of the inclined plane structure of the metal sheet 1 connected to the tab glue 2 can meet the production requirements. For example, a thinning structure with double-sided thinning treatment or single-sided thinning treatment.
[0046] Before the thinning treatment, the included angle between the upper and lower surfaces of the thinning structure 3, the inclination angle between the upper surface and the horizontal plane, the inclination angle between the lower surface and the horizontal plane, the width of the thinning structure, and other process parameters can be set accordingly according to the thickness requirements of the metal sheet of the tab, and corresponding processing can be carried out according to the pre-set process parameters.
[0047] For example, in some embodiments, the included angle between the two inclined planes formed by the thinning structure 3 is 30 to 40 degrees, and the width of the thinning structure is 2.0 to 3.0 mm.
[0048] In some embodiments, the upper and lower surfaces of the thinning structure 3 are symmetrical structures, that is, the inclination angle between the upper surface of the thinning structure and the horizontal plane is the same as the inclination angle between the lower surface and the horizontal plane, and the cross-section of the thinning structure is triangular.
[0049] During the hot pressing and compounding process of the tab and the packaging bag, the tab glue in the molten state penetrates into the end face of the thinned structure. The gently decreasing thickness difference makes the tab glue and the end face of the metal sheet thinned structure form a smoother bite surface, which, on the one hand, increases the packaging strength between the end of the metal sheet of the tab and the tab glue, and on the other hand, reduces the bulge phenomenon of overflow glue accumulation, improves the flatness of the tab edge sealing, and reduces the risk of tab edge cracking and electrolyte leakage.
[0050] In some embodiments, the thickness of the metal sheet 1 is greater than or equal to 0.2 mm. It should also be noted that in the specific implementation of the embodiments of the present disclosure, for the tabs with a thickness greater than or equal to 0.2 mm, the corresponding bending times of the tabs made of aluminum, nickel and nickel-plated copper materials should reach 5 times or more to meet the shock resistance and fatigue toughness tests of EV power applications. These requirements ensure the reliability and durability of the tab metal sheet during battery use.
[0051] In some embodiments, the thinning structure 3 has a conical shape and a curved surface. The round and thick end of the conical thinning structure is connected to the ends of both sides of the main body of the metal sheet 1, and the sharp end of the conical thinning structure is away from the ends of both sides of the main body of the metal sheet.
[0052] In some embodiments, the thinned structure 3 is a single-sided thinned structure, that is, only the upper surface or the lower surface of the thinned structure is an inclined surface.
[0053] Specifically, during the production of the tab, only the ends on both sides of the main body of the metal sheet 1 are subjected to upper surface thinning or lower surface thinning to form a thinning structure with a single surface (upper surface or lower surface) being an inclined surface.
[0054] In some embodiments, when the tab metal sheet is relatively thin, for example, the thickness of the metal sheet 1 is greater than or equal to 0.2 mm, after thinning the ends of both sides of the metal sheet, a smaller angle is formed at the junction of the upper and lower inclined surfaces of the thinning structure 3. During the hot pressing and compounding process of the tab and the packaging bag, the upper and lower layers of tab glue change smoothly with the angle of the bevel of the thinning area until the upper and lower glue layers are connected and bonded together.
[0055] In some embodiments, when the thickness of the metal sheet 1 increases, the angle between the two inclined surfaces formed by the thinning structure 3 increases accordingly.
[0056] Specifically, when the metal sheet of the tab becomes thicker, as the capacity of the battery cell increases, the current-carrying capacity of the tab also needs to increase, and the production needs can be met by increasing the thickness of the tab (i.e., the thickness of the metal sheet).
[0057] Therefore, for the thickened metal sheet, after thinning the ends on both sides of the metal sheet, a thinning structure is formed, and the angle formed by the connection between the upper and lower inclined planes of the thinning structure increases accordingly. During the hot pressing and compounding process of the tab and the packaging bag, the upper and lower tab adhesives fit smoothly with the change of the inclined angle of the thinning area until the upper and lower adhesive layers are connected and fitted together. Compared with the tab without the thinning structure, the tab manufactured according to this embodiment can significantly increase the adhesion between the tab adhesive and the metal sheet.
[0058] In the case of the thickening of the tab metal sheet, by setting a thinning structure on the end faces on both sides of the metal sheet of the tab, the problem that the end face drop between the connection of the metal sheet and the tab adhesive is greater than the thickness of the tab adhesive itself can also be solved. During the hot pressing and compounding process of the tab and the packaging bag, the tab adhesive in the molten state penetrates to the end face of the thinning structure, and the gradually decreasing thickness drop makes the end face of the tab adhesive and the metal sheet thinning structure form a relatively smooth bonding surface. On the one hand, it can increase the packaging strength between the end of the tab metal sheet and the tab adhesive, and on the other hand, it can reduce the raised phenomenon of glue overflow and accumulation, improve the flatness of the tab edge sealing, and at the same time reduce the risks of tab edge cracking and electrolyte leakage.
[0059] The tabs prepared by applying the present utility model and the tabs without the thinning structure are encapsulated, and the peeling force of the tab adhesive of the two types of tab samples is tested. The test comparison results are shown in Table 1. The tabs prepared by applying the present utility model can increase the peeling force of the tab adhesive by more than 15%.
[0060] Table 1
[0061]
[0062] The embodiment of the present disclosure also provides a soft-pack battery, including a battery cell and the above-mentioned tab, wherein the tab is used to connect the battery cell and an electrical appliance.
[0063] Specifically, the soft-pack battery is a lithium-ion battery, and its name comes from the packaging form of the battery. Compared with traditional cylindrical or prismatic batteries, the soft-pack battery uses a flexible external material for packaging, usually an aluminum-plastic composite film. The outer shell of the soft-pack battery is made of an aluminum-plastic composite film, which has good flexibility and formability and can be made into different shapes and sizes according to needs.
[0064] The battery cell is the part of the battery responsible for storing and releasing electrical energy, and is composed of a positive electrode, a negative electrode, a separator, an electrolyte, etc. The battery cell realizes the storage and release of electrical energy through chemical reactions.
[0065] The tabs are led out from the positive and negative electrodes of the battery cell and serve as the current collection and transmission points. Through the tabs, the battery cell is connected to an external electrical appliance to provide electrical energy to the external electrical appliance.
[0066] In the embodiments of the present disclosure, by providing a thinning structure on the end faces on both sides of the metal sheet of the tab, during the thermocompression lamination process of the tab and the packaging bag, the tab glue in a molten state penetrates to the end faces of the thinning structure, and the gradually decreasing thickness difference enables the tab glue and the end faces of the metal sheet thinning structure to form a relatively smooth bonding surface. On the one hand, it can increase the packaging strength between the end of the metal sheet of the tab and the tab glue, and on the other hand, it can reduce the raised phenomenon of glue overflow and accumulation, improve the flatness of the tab edge sealing, and at the same time reduce the risks of tab edge cracking and electrolyte leakage.
[0067] So far, the embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Those skilled in the art can clearly understand how to implement the technical solutions disclosed herein based on the above description.
[0068] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be equivalently replaced without departing from the scope and spirit of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way.
Claims
1. A tab, characterized in that: The tab comprises: a metal sheet (1) and tab glue (2); The metal sheet (1) comprises a thinning structure (3), wherein the thinning structure (3) is arranged at the ends of both sides of the main body of the metal sheet, and the thickness of the thinning structure decreases along the main body of the metal sheet towards the ends of the metal sheet; The tab glue (2) is used to cover the metal sheet (1).
2. The tab according to claim 1, characterized in that: The thickness of the metal sheet (1) is greater than or equal to 0.2 mm.
3. The tab according to claim 1, characterized in that: The tab glue (2) in a molten state penetrates into the end surface of the thinned structure (3), so that the tab glue (2) and the end surface of the thinned structure form a smooth occlusal surface.
4. The tab according to claim 1, characterized in that: The upper and lower surfaces of the thinning structure (3) are both inclined surfaces.
5. The electrode tab according to claim 4, characterized in that: The included angle between the two inclined surfaces formed by the thinning structure (3) is 30 to 40 degrees.
6. The tab according to claim 4, characterized in that: The cross section of the thinned structure (3) is triangular.
7. The tab according to claim 4, characterized in that: When the thickness of the metal sheet (1) increases, the angle between the two inclined surfaces formed by the thinning structure (3) increases accordingly.
8. The tab according to claim 1, characterized in that: The width of the thinning structure (3) is 2.0 to 3.0 millimeters.
9. The tab according to claim 1, characterized in that: The upper and lower surfaces of the thinning structure (3) are symmetrical structures.
10. A soft pack battery, characterized in that: It comprises a battery cell and the electrode tab as claimed in any one of claims 1 to 9, wherein the electrode tab is used to connect the battery cell and an electrical appliance.