Tab, soft package battery and electric equipment

Abstract

The invention relates to a tab, a soft package battery and electric equipment, and belongs to the technical field of batteries. The tab comprises a metal plate connecting piece and double-layer tab glue, non-filling via holes are formed in a metal plate, the first and second glue coating layers form an interlocking structure through hot melting and interpenetration of the via holes, and the conductivity and the bonding strength are balanced by combining the parameter relation design of the diameter and the number of the via holes and the width of the metal plate; the sealing performance is enhanced through ultra-wide coating of the tab glue and penetration depth / thickness ratio control, the process reliability is optimized through porous combination and edge distance constraint, the battery tab structure with high binding force, permeation resistance and low cost is achieved, and the requirement of a high-energy-density soft package battery is met.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to tabs, soft-pack batteries, and electrical equipment. Background Art

[0002] With the development of technology in the field of new energy batteries, soft-pack battery technology has been widely used in the fields of consumer electronics and electric vehicles due to its advantages of high specific energy, lightweight and customizability. Soft-pack battery technology uses a flexible packaging film to wrap the electrode group and the pole ear, and achieves overall sealing through a hot pressing process. The pole ear, as the current output end, must meet both conductivity and packaging reliability requirements.

[0003] In the related art, the traditional soft-pack battery tab packaging process uses a hot-pressing method to combine the metal connecting sheet and the tab glue, and utilizes the hot-pressing temperature field to promote the formation of an adhesive layer between the polymer tab glue and the metal surface.

[0004] However, when the width of the tab is wider, there is a risk of peeling and sealing failure in the bonding area between the tab metal plate and the tab glue during use of the battery cell, resulting in battery leakage and failure; in addition, a short circuit may occur in the soft-pack battery during use, triggering thermal runaway, and the internal temperature of the battery cell will rise sharply. If the circuit cannot be effectively disconnected to avoid thermal runaway, it will threaten the safety of people and property. Summary of the Invention

[0005] Based on this, it is necessary to provide a tab, a soft-pack battery and electrical equipment to address the above problems, so as to improve the bonding strength between the tab glue and the connecting piece in the tab structure, avoid the risk of peeling and sealing failure between the two, further improve the quality of the soft-pack battery products, and avoid the risk of failure during use.

[0006] A tab comprises a connecting piece and tab glue, wherein at least one via hole is provided on the connecting piece;

[0007] The tab glue is divided into a first rubber coating layer and a second rubber coating layer, the first rubber coating layer and the second rubber coating layer respectively cover both sides of the connecting piece in the thickness direction and are connected through the via hole;

[0008] Furthermore, the first encapsulation layer and the second encapsulation layer are directly bonded together through vias to form an interlocking structure.

[0009] In one embodiment, the span d of the via in the width direction x of the connecting piece satisfies: 0.5mm≤d≤20mm, and the number n of the vias satisfies the relationship: 0.3≤(an×d) / a≤0.8, where a is the width of the connecting piece, and 5mm≤a≤100mm.

[0010] In one embodiment, the thickness t of the connecting piece satisfies: 0.2 mm ≤ t ≤ 5 mm, and the ratio between the thickness t of the connecting piece and the span d of the via in the width direction x of the connecting piece satisfies: 0.3 ≤ d / t.

[0011] In one embodiment, the shape of the via hole is selected from one or more combinations of circular, elliptical, fan-shaped or polygonal.

[0012] In one embodiment, the width C of the tab glue exceeding the side portion in the width direction x of the connecting piece satisfies: 2mm≤C≤50mm.

[0013] In one embodiment, the fusion depth h6 of the first rubber layer and the second rubber layer at the joint in the thickness direction z of the connecting piece satisfies: 0.06mm≤h6≤8mm; the thickness h5 of the tab rubber satisfies: 0.2mm≤h5≤10mm; and the ratio of the fusion depth h6 to the thickness h5 satisfies: 0.3≤h6 / h5≤0.8.

[0014] In one embodiment, the margin K1 between the via hole and the tab glue satisfies: 0.3mm≤K1≤20mm; wherein K1 is the margin between the via hole and the side edge of the tab glue along the length direction y of the connecting piece.

[0015] In one embodiment, the margin K2 between the via hole and the connecting piece satisfies: 0.2 mm ≤ K2 ≤ 20 mm; wherein K2 is the margin between the via hole and the side edge of the connecting piece along the width direction x of the connecting piece.

[0016] On the other hand, the present application also provides a soft-pack battery, comprising the tab as described above.

[0017] On the other hand, the present application also provides an electrical device that is powered by the above-mentioned soft-pack battery.

[0018] The above-mentioned tabs, soft-pack batteries, and electrical equipment achieve direct hot-melt bonding of the first and second adhesive layers through vias to form a physical interlocking structure, which significantly improves the bonding strength between the tab adhesive layers. Compared with the traditional flat bonding of adhesive layers, the interlocking structure can resist peeling force. At the same time, the vias of the present application are not filled with other materials, and the tab adhesive itself is directly melted and interpenetrated for bonding, which simplifies the process steps while avoiding the compatibility problem of heterogeneous material interfaces and improving structural consistency.

[0019] This application also has the following advantages:

[0020] (1) The mathematical relationship between the via parameters (span d in the width direction x, number n) and the width a of the connecting piece (0.3≤(an×d) / a≤0.8) of the present application scientifically balances the remaining cross-sectional area of the connecting piece and the bonding area, ensuring that the connecting piece retains sufficient conductive cross-sectional area, reducing resistance, thereby providing a sufficient hot melt bonding interface and enhancing the mechanical anchoring effect; at the same time, the via parameters can maximize the utilization of the connecting piece while ensuring performance and reduce the ineffective loss of the connecting piece;

[0021] (2) The design of the tab glue of the present application that exceeds the width of the side of the connecting piece (2-50mm) forms a "edge effect", which can effectively prevent the electrolyte from penetrating along the edge of the connecting piece, while dispersing the edge stress and preventing the seal from cracking;

[0022] (3) The precise control of the penetration depth of the present application and the limitation of the ratio of the penetration depth h6 to the PP layer thickness h5 (0.3-0.8) achieve a balance between deep bonding and material integrity. Sufficient penetration depth ensures the bonding strength and retains the unmelted PP layer to maintain the material toughness, avoiding excessive melting that causes the adhesive layer to become thin and ineffective.

[0023] (4) This application simplifies the production process. No filling material is required in the via hole. The interlocking structure between the upper and lower rubber layers can be formed by hot pressing, thereby improving production efficiency.

[0024] (5) The via area of the present application forms a fuse part, and there is no filling material in the via. After the interlocking structure between the upper and lower rubber layers is completed by hot pressing, a certain degree of depression in the thickness z direction will be formed in the interlocking area, and the tab glue and the aluminum-plastic film subsequently formed on the surface of the tab glue will be stretched to a certain extent. When the fuse part is melted, the tensile force can promote the molten tab glue in the melting area to flow to the melting gap, thereby avoiding the arcing secondary short circuit of the melting part. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the tab structure of this application.

[0026] Figure 2 for Figure 1 AA section view in.

[0027] Figure 3 for Figure 2 Magnified view of part I in .

[0028] Figure 4 This is a schematic structural diagram of the connecting piece of this application.

[0029] Figure 5 for Figure 4 BB section view in.

[0030] Figure 6 Schematic diagram of various parameters in this application.

[0031] Among them: 100, connecting piece; 200, ear glue;

[0032] 110. Metal plate; 120. Via hole;

[0033] 210, first rubber layer; 220, second rubber layer. DETAILED DESCRIPTION

[0034] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0035] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does 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.

[0036] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0037] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0038] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0040] See Figure 1 , shows a schematic structural diagram of a tab in an embodiment of the present application. An embodiment of the present application provides a tab, including a connecting sheet 100 and a tab glue 200.

[0041] In some embodiments, the connecting piece 100 is made of metal, and the main structure is a metal plate 110 .

[0042] Furthermore, one end of the metal plate 110 is connected to the battery cell electrode group, and the other end is used for external conductive connection, such as connection to an electrical device or a busbar; at the same time, the material of the metal plate 110 is matched based on the properties of the battery cell, preferably aluminum or copper, and the width a of the metal plate 110 satisfies 5mm≤a≤100mm;

[0043] The thickness t of the metal plate 110 satisfies: 0.2mm≤t≤5mm, and the ratio between the thickness t of the metal plate 110 and the span d of the via 120 in the width direction x of the metal plate 110 satisfies: 0.3≤d / t. This ratio can be used to determine the matching relationship between the size of the via 120 and the thickness of the metal plate 110.

[0044] In a specific embodiment, a plurality of through holes 120 are provided in the width direction x of the metal plate 110, which penetrate the thickness of the metal plate 110. The shape of the through holes 120 can be circular, oblong, elliptical, fan-shaped or polygonal (eg Figure 4As shown, the vias 120 are arranged in a circular pattern, and the span d in the width direction x satisfies 0.5 mm ≤ d ≤ 20 mm. The number n is determined according to the formula 0.3 ≤ (an × d) / a ≤ 0.8 to balance the remaining conductive cross-sectional area of the metal plate 110 and the bonding area of the tab glue 200;

[0045] For example, when a=50 mm, if d=5 mm, then n must satisfy 5≤n≤8.

[0046] In another specific embodiment, the metal plate 110 is provided with only one via 120 extending through its thickness in the transverse direction x. The shape of the via 120 is circular, oblong, elliptical, sector-shaped, or polygonal. The span d of the via 120 in the width direction x of the metal plate 110 satisfies 0.5 mm ≤ d ≤ 20 mm. In particular, when there are fewer vias, such as only one, the shape of the via 120 is preferably oblong or elliptical, and the long side of the oblong or elliptical is parallel to the width direction x. This facilitates achieving a balance between the remaining conductive cross-sectional area of the metal plate 110 and the bonding area of the tab glue 200, without excessively occupying the longitudinal area of the metal plate 110.

[0047] In some embodiments, the tab glue 200 is composed of a first rubber coating layer 210 and a second rubber coating layer 220, which respectively cover the upper and lower surfaces of the metal plate 110 along the thickness direction of the metal plate 110; wherein, the first rubber coating layer 210 and the second rubber coating layer 220 are made of polypropylene (PP) material, and the thickness h5 is 0.2-10mm.

[0048] See also Figures 2 to 3 During the hot pressing process, the molten portions of the first rubber coating layer 210 and the second rubber coating layer 220 directly contact and melt each other through the via hole 120, forming an interlocking structure that penetrates the thickness of the metal plate 110; the melting depth h6 of the interlocking structure is 0.06-8mm, and satisfies 0.3≤h6 / h5≤0.8, so as to ensure a balance between bonding strength and material toughness; it can be understood that the via hole area where the via hole 120 is located forms a fuse part, and a melting area is formed under thermal runaway state by reducing the flow cross section; specifically, there is no filling material in the via hole 120. After the interlocking between the first rubber coating layer 210 and the second rubber coating layer 220 is completed by hot pressing, a certain degree of depression in the thickness direction z will be formed in the interlocking area, and the tab glue and the aluminum-plastic film subsequently formed on the surface of the tab glue will be stretched to a certain extent, that is, a force in the thickness direction z will be formed. When the fuse part is melted, the stretching force can promote the molten tab glue in the melting area to flow to the melting gap, thereby avoiding arcing and secondary short circuit of the melting part.

[0049] Please continue reading Figure 4 and Figure 5The width C of the tab glue 200 exceeding the side of the metal plate 110 in the width direction x is 2-50 mm; the ultra-wide coating forms a "edge effect", which can effectively prevent the electrolyte from penetrating along the edge of the metal plate 110, and at the same time disperse the edge stress when the tab is subjected to force.

[0050] Please continue reading Figure 6 The margin K1 (along the length direction y of the metal plate) between the via 120 and the side of the tab glue 200 is 0.3-20 mm, and the margin K2 (along the width direction x of the metal plate) between the via 120 and the side of the metal plate 110 is 0.2-20 mm. The limitation of the margins K1 and K2 can prevent the material from overflowing during hot melting and causing a short circuit, and can also prevent the via 120 from being too close to the edge and causing the metal plate 110 to break.

[0051] In other embodiments, the present application also provides a soft-pack battery comprising the above-mentioned tab.

[0052] Furthermore, after welding the tabs to the cell electrode assembly, the soft pack battery is packaged according to the following steps:

[0053] Place the electrode group in the lower aluminum-plastic film punching hole, with the positive and negative tabs leading out from both ends;

[0054] Cover with aluminum plastic film, align the four sides and then perform hot melt plastic sealing;

[0055] Pressure is applied to the tab region to fully fuse the first encapsulation layer 210 and the second encapsulation layer 220 through the via hole 120 to form an interlocking sealing structure without filling material.

[0056] In other embodiments, the soft-pack battery of the present application can be integrated into electrical equipment such as electric vehicles, portable electronic devices or energy storage devices; the battery tabs can maintain sealing integrity under various harsh working conditions due to the high bonding strength of the interlocking structure between the upper and lower layers of rubber and the wide-edge sealing design (C ≥ 2mm), thereby preventing electrolyte leakage.

[0057] Compared with traditional tabs, the tabs in this application have improved bonding strength and improved packaging qualification rate; the parameter design of the via 120 balances the remaining cross-sectional area and the bonding area on the metal plate 110, ensuring that the metal plate 110 retains sufficient conductive cross-sectional area, reduces resistance, and also provides sufficient hot melt bonding interface to enhance the mechanical anchoring effect; at the same time, no other materials are filled in the via 120, and the tab glue 200 itself is directly used for melting and interpenetrating bonding, which simplifies the process steps while avoiding the compatibility problem of heterogeneous material interfaces and improving structural consistency.

[0058] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A tab, comprising a connecting sheet and tab glue, characterized in that: At least one via hole is provided on the connecting piece; The tab glue is divided into a first rubber coating layer and a second rubber coating layer. The first rubber coating layer and the second rubber coating layer respectively cover both sides of the connecting piece in the thickness direction (z) and are connected through the via hole.

2. The tab according to claim 1, wherein: The span d of the via in the width direction (x) of the connecting piece satisfies: 0.5mm≤d≤20mm, and the number n of the vias satisfies the relationship: 0.3≤(an×d) / a≤0.8, where a is the width of the connecting piece, and 5mm≤a≤100mm.

3. The tab according to claim 2, wherein: The thickness t of the connecting piece satisfies: 0.2 mm ≤ t ≤ 5 mm, and the ratio between the thickness t of the connecting piece and the span d of the via hole in the width direction (x) of the connecting piece satisfies: 0.3 ≤ d / t.

4. The tab according to claim 1, wherein: The shape of the via is selected from one or more combinations of circular, oblong, elliptical, fan-shaped and polygonal; preferably, the via includes at least one of oblong and elliptical shapes, and the long side of the oblong and elliptical shape is parallel to the width direction (x) of the connecting piece.

5. The tab according to claim 1, wherein: The width C of the tab glue exceeding the side portion in the width direction (x) of the connecting piece satisfies the following: 2mm≤C≤50mm.

6. The tab according to claim 1, wherein: The fusion depth h6 of the first and second rubber layers at the joint in the thickness direction (z) of the connecting piece satisfies: 0.06mm≤h6≤8mm; the thickness h5 of the tab rubber satisfies: 0.2mm≤h5≤10mm; and the ratio of the fusion depth h6 to the thickness h5 satisfies: 0.3≤h6 / h5≤0.

8.

7. The tab according to claim 1, wherein: The margin K1 between the via hole and the side edge of the tab glue along the length direction (y) of the connecting piece satisfies the following conditions: 0.3 mm ≤ K1 ≤ 20 mm.

8. The tab according to claim 1, wherein: A margin K2 between the via hole and the side edge of the connecting piece along the width direction (x) of the connecting piece satisfies the following: 0.2 mm ≤ K2 ≤ 20 mm.

9. A soft pack battery, characterized in that: The method comprises the tab according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The soft pack battery as claimed in claim 9 is used for power supply.

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