Tab structure

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a tab structure which comprises a packaging body packaged with a pole piece and an extension body connected with the packaging body, the extension body is welded with a fuse link which flows through the tab structure and is fused when the current is greater than or equal to a current threshold value of the tab structure, and the fuse link and the packaging body are arranged at an interval; on one hand, the property that the fuse link is fused after the resistance is increased at a relatively high temperature is utilized, the combustion explosion of the battery is prevented, and on the other hand, the condition that the fuse link is easily fused in the welding process of the tab packaging part and the pole piece is avoided, so that the generation of defective pole pieces and defective batteries is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to a pole ear structure. Background Art

[0002] With the rapid advancement of electronic technology, lithium-ion electrodes are increasingly being used in my country as an efficient and environmentally friendly energy storage device. However, when lithium batteries are overcharged, short-circuited, or have excessive operating current, continued operation may cause the battery temperature to rise, leading to safety hazards such as combustion and explosion.

[0003] In current battery technology, the tab structure, as a key component of the battery, is responsible for connecting the positive and negative electrodes of the battery with the external circuit, thereby realizing the transmission of electrical energy. However, the traditional tab structure has certain hidden dangers in terms of safety. For example, when the working current is too large, the input and output of the tab structure may be affected, thereby causing accidents such as battery combustion or even explosion.

[0004] Based on this, there is an urgent need for an improvement in the tab structure to solve the aforementioned technical defects. Utility Model Content

[0005] The purpose of the utility model is to propose a pole ear structure to improve the safety performance of the battery and effectively prevent accidents such as battery combustion and explosion caused by excessive working current.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A pole ear structure comprises a package body packaged with a pole piece and an extension body connected to the package body, the extension body is welded with a fuse piece which is fused when a current greater than or equal to a current threshold flows through the pole ear structure, and the fuse piece is spaced apart from the package body.

[0008] The above-mentioned pole ear structure proposed by the utility model has the following technical effects:

[0009] First, the pole ear structure design of the utility model can be quickly blown when a short circuit occurs. When a traditional battery pole ear structure encounters a short circuit, the resistance heat may cause the battery temperature to rise, thereby causing a safety accident. However, the utility model uses the design of the fuse to enable the pole ear to be quickly blown when a short circuit occurs, effectively reducing the failure rate of the battery cell. This design reduces the risk of battery failure to a certain extent and improves the safety performance of the battery.

[0010] Secondly, the utility model further enhances the stability of the tab structure by setting a gap between the fuse and the package. In view of the fact that a large amount of heat will be generated during the welding process between the tab package and the pole piece, the heat can be better dispersed through the gap between the fuse and the package, reducing the risk of the tab fuse being melted due to high temperature before being put into use. At the same time, this design also helps to maintain the stability and reliability of the battery cell, thereby further improving the safety performance of the battery.

[0011] As an improvement to the pole ear structure of the utility model, the extension body is provided with a groove portion, and the fuse piece is accommodated in the groove portion by laser welding.

[0012] As an improvement to the structure of the pole ear of the utility model, the depth of the groove portion is equal to the thickness of the fuse piece.

[0013] As an improvement to the tab structure of the utility model, the extension body includes a first body and a second body connected to the first body, the second body is connected to the first body through a groove portion, and the second body is spaced between the fuse piece and the packaging body.

[0014] As an improvement to the structure of the pole ear of the utility model, the distance D between the fuse piece and the packaging body is 2-4 mm.

[0015] As an improvement to the tab structure of the utility model, the widths of the first body, the second body and the fuse are equal. Assuming their widths are L, the width of the package is L', and L and L' satisfy the relationship: 2 / 3L'≥L≥1 / 2L'.

[0016] As an improvement to the tab structure of the utility model, the width of the extension body is smaller than the width of the packaging body.

[0017] As an improvement to the tab structure of the utility model, the packaging body includes a first part and a second part connected to the first part, the first part is connected to the extension body, and the first part is coated with tab glue.

[0018] As an improvement to the structure of the pole ear of the utility model, the structures of the first part and the second part are the same, and their area ratio is 1:2.

[0019] As an improvement to the pole ear structure of the utility model, the second part is connected with a connector, the connector is symmetrically arranged along the packaging body and the extension body, and the connector is electrically connected to the pole piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0021] Figure 1 It is a schematic diagram of the structure of the pole ear in the embodiment of the utility model;

[0022] Figure 2 It is a side view of the tab structure in the embodiment of the utility model;

[0023] Figure 3 It is a side view of the structure of the pole ear in which the thickness of the groove part is greater than the thickness of the fuse piece in the embodiment of the utility model;

[0024] Figure 4 This is a schematic diagram of the relationship between the depth of the groove and the fuse in the embodiment of the utility model;

[0025] Figure 5 It is a side view of the structure of the pole ear in which the groove part and the fuse piece adopt different shapes in the embodiment of the utility model;

[0026] Figure 6 This is a schematic diagram of the relationship between the groove portion and the width of the fuse piece in the embodiment of the utility model;

[0027] Figure 7 Schematic diagram of the distance relationship between the package body and the fuse in the embodiment of the utility model.

[0028] in:

[0029] 1-Package;

[0030] 11 – Part 1; 12 – Part 2;

[0031] 121 - connector;

[0032] 2- extension body;

[0033] 21 - groove portion; 22 - first body; 23 - second body;

[0034] 3- Fuse. DETAILED DESCRIPTION

[0035] In order to make the technical solution and advantages of the utility model clearer, the utility model and its beneficial effects will be further described in detail below in conjunction with specific implementation methods and drawings of the specification, but the implementation methods of the utility model are not limited thereto.

[0036] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

[0038] Embodiment 1:

[0039] like Figure 1 As shown, a tab structure includes a package body 1 packaged with a pole piece and an extension body 2 connected to the package body 1, the extension body 2 is welded with a fuse 3 that is blown when the current flowing through the tab structure is greater than or equal to its current threshold, and the fuse 3 is spaced apart from the package body 1. Among them, the main function of the package body 1 is to package and weld with the pole piece to ensure the stability and safety of the pole piece in the tab structure. It is worth noting that there is a certain interval between the fuse 3 and the package body 1 to ensure that the heat generated by welding will not cause the fuse connected to the tab package to be heated and melted during the packaging welding of the tab package body and the pole piece. The function of the extension body 2 is to connect the package body 1 with the fuse 3 and transmit current. In a specific embodiment, the extension body 2 is usually made of a material with good conductive properties, such as copper or aluminum. One end of the extension body 2 is welded to the package body 1 or connected by other means, and the other end is welded to the fuse 3 or connected by other means. Under normal working conditions, current will flow through the extension body 2 through the fuse 3. In a specific embodiment, the fuse 3 is usually made of a metal wire with a certain cross-sectional area and a certain melting point. When the current flowing through the fuse 3 exceeds the threshold of the fuse 3, the fuse 3 will melt due to overheating, thereby cutting off the current and protecting the tab structure and the battery cell from damage caused by overcurrent.

[0040] Preferably, Figure 2As shown, the extension body 2 is equipped with a groove portion 21, and the fuse 3 is placed in the groove portion 21 by laser welding technology. The key advantage of the connection structure between the groove portion 21 and the extension body 2 is that its design is not only conducive to the placement of the fuse 3, but also improves the safety performance of the battery to a certain extent. In the case of overcharging or over-discharging of the battery, the fuse 3 can be melted in the groove portion 21 and quickly cut off the circuit to prevent the battery from short-circuiting and ensure the safety of the user. In addition, the groove portion 21 can also relieve the stress concentration of the battery during the charging and discharging process, improve the flatness of the pole ear, and indirectly extend the service life of the battery. At the same time, in addition to the connection function with the extension body 2, the groove portion 21 also has the function of supporting and protecting the fuse 2. Compared with the method of directly connecting the two ends of the fuse 3 to the extension body 2, the groove portion 21 can enable the fuse 3 to maintain a stable posture during installation and operation, and can also prevent external physical damage. In a specific embodiment, the material of the groove portion 21 may be a non-conductive material, because its main function is to assist the fuse piece 3 in connecting with the extension body 2 and it has no actual conductive property.

[0041] In this embodiment, the fuse 3 and the extension body 2 are connected by laser welding. Laser welding is a high-precision and high-efficiency welding method. By focusing the laser beam to generate high temperature in the welding area, the fuse 3 and the extension body 2 are welded together. This welding method has the advantages of precise welding point area, fast welding speed, high weld quality, and high welding strength, ensuring the firm connection between the fuse 3 and the extension body 2. At the same time, laser welding will not cause the fuse 3 to be completely melted due to high temperature, thereby losing the function of protecting the tab structure and the battery cell from overcurrent damage. In addition, in order to cooperate with the laser welding with the fuse 3, the extension body 2 also optimizes the selection of its material and the shape of the extension body 2. Specifically, the material of the extension body 2 is selected from high-quality materials with good welding performance and strength, such as stainless steel or aluminum alloy. The selection of this material not only ensures the strength of the extension body 2, but also enables it to be closely combined with the fuse 3 during the laser welding process, thereby improving the welding effect. In addition, the shape of the extension body 2 is designed to be a groove shape matching the fuse 3 to facilitate laser welding. This design makes the connection between the fuse piece 3 and the extension body 2 more stable, which is conducive to the fuse piece 3 playing a role in protecting the tab structure and the battery cell.

[0042] Preferably, the depth of the groove 21 is equal to the thickness of the fuse 3. Figure 2 As shown, by adjusting the depth of the groove 21 to be equal to the thickness of the fuse 3, the groove 21 can better interact with the fuse 3, which indirectly helps to reduce resistance and energy loss, so that the product can maintain stable performance during long-term operation. Figure 3As shown, when the depth of the groove 21 is less than the depth of the fuse 3, it can ensure that the fuse 3 can be smoothly fused after exceeding the threshold current. The purpose of such a design is to ensure that the fuse 3 can be fully expanded when the current exceeds the threshold current, thereby ensuring the smooth fusing process. In addition, the wide groove 21 can also improve the stability of the fuse 3 and avoid deformation or cracking in a high temperature environment.

[0043] like Figure 4 As shown, in a specific embodiment, the width of the groove portion 21 can be adjusted according to specific circuit requirements and design parameters. Generally speaking, the ratio of the thickness H of the groove portion 21 to the thickness h of the fuse 3 should be between 1.5:1 and 2:1. Such a ratio can ensure that the fuse 3 can be fully expanded and quickly blown when the current exceeds the threshold.

[0044] like Figure 5 As shown, based on the above embodiment, the groove portion 21 can be designed as a trapezoidal, triangular or non-circular structure. For example, Figure 5 The groove portion 21 is in a trapezoidal shape, and this design is conducive to improving the stability of the fuse piece 3, making it less likely to deform during high-temperature welding.

[0045] At the same time, the width of the groove portion 21 can also be adjusted according to actual needs. By comparing the groove portions 21 with different widths, the applicant has found that Figure 6 As shown, when the width of the groove portion 21 is smaller than that of the extension body 2, the product can better disperse stress and reduce the risk of breakage when subjected to external force. In addition, the width of the groove portion 21 is smaller than the width of the extension body 2, which also helps to improve the bending resistance of the product. In practical applications, when the product is subjected to bending stress, the narrow design of the groove portion 21 can effectively reduce the concentration of bending stress and make the stress distribution more uniform. At the same time, this design has a positive effect on the wear resistance of the pole ear. Since the width of the groove portion 21 is small and the width of the extension body 2 is large, the transition area between the two is relatively smooth, which reduces the wear of the product during movement and enables the extension body 2 to maintain good performance during long-term use.

[0046] In a specific embodiment, in order to further improve the fusing performance of the fuse 3, an alloy material with a melting point of 90-110 degrees, good electrical conductivity and thermal conductivity, such as Wood's alloy, tin-bismuth alloy, etc., can be selected to make the fuse 3, and coated with an anti-oxidation coating such as ceramic materials such as aluminum oxide and silicon oxide. Through the above-mentioned optimization of the fuse material, the working stability of the fuse 3 in a more severe environment can be improved. (For example, in an extremely high temperature working environment, the impact of the external environment on the fuse in the ear structure inside the battery cell can be reduced through optimization.) At the same time, in a specific embodiment, the surface of the fuse 3 is coated with a layer of anti-oxidation coating, which can effectively prevent the fuse 3 from oxidizing during high-temperature welding, thereby increasing its service life.

[0047] Preferably, the extension body 2 includes a first body 22 and a second body 23 connected to the first body 22, the second body 23 is connected to the first body 22 through the groove portion 21, and the second body 23 is spaced between the fuse 3 and the package body 1. In a specific embodiment, the second body 23 of the extension body 2 is intended to ensure that the fuse 3 will not be melted during the welding process between the tab package body 1 and the pole piece package, and its shape and length can be adaptively adjusted according to the specific working environment and different specifications of the battery cell, so as to more comprehensively ensure the safety performance of the battery cell.

[0048] Embodiment 2:

[0049] like Figure 1 As shown, the width of the extension body 2 is smaller than the width of the package body 1. This width difference can effectively reduce the risk of the extension body 2 breaking during the packaging of the pole ear and the pole piece. The specific reason is that when the width of the extension body 2 is smaller than the width of the package body 1, the package body 1 can withstand greater stress (compared to the extension body 2), thereby greatly reducing the possibility of damage to the extension body 2. In addition, in a specific embodiment, the hardness of the package body 1 is higher than that of the extension body 2. Through this design, the package body 1 can also exert anti-wear performance during the packaging process, thereby extending the service life of the produced pole ear. Even under frequent use and wear, the package body 1 can maintain good performance and ensure the stability and reliability of the extension body 2.

[0050] Embodiment 3:

[0051] like Figure 7As shown, the distance D between the fuse piece 3 and the package body 1 is 2-4mm. Specifically, the spacing distance can be set to: 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, etc. In a specific embodiment, the spacing distance can be appropriately adjusted according to the specifications of the battery cell to be prepared. However, too large or too small a spacing distance will affect the fusing performance of the fuse piece 3 and the packaging effect of the package body 1. Specifically, if the spacing is reduced to 2.5mm, it may have certain advantages in terms of cost saving, because a smaller spacing usually means a lower manufacturing cost. However, too small a spacing may also increase the risk of the fuse piece 3 being blown during welding.

[0052] Embodiment 4:

[0053] like Figure 1 and Figure 2 As shown, the package body 1 in this embodiment includes a first part 11 and a second part 12 connected to the first part 11, the first part 11 is connected to the extension body 2, and the first part 11 is coated with a tab glue. As a high-performance packaging material, the tab glue has excellent heat resistance, insulation and corrosion resistance, and it can provide all-round protection for the package body 1, thereby ensuring its stability and reliability during use.

[0054] Preferably, the first part 11 and the second part 12 have the same structure, and their area ratio is 1:2. Since the battery has higher requirements for welding stability, in order to ensure the stability of the pole piece under the influence of external force, this type of battery needs to reduce the coating area of ​​the ear glue and increase the welding area. However, in a specific embodiment, another part of the battery cell needs to ensure the stability of the pole piece under the influence of external force and increase the coating amount of the ear glue. In this process, we need to note that increasing the coating amount of the ear glue does not mean that it can be increased indefinitely. Too much ear glue may cause the battery to increase in size and weight, thereby affecting the portability of the battery.

[0055] Preferably, the widths of the first body 22, the second body 23 and the fuse 3 are equal. Let their widths be L, and the width of the package body 1 be L'. L and L' satisfy the relationship: 2 / 3L'≥L≥1 / 2L'. In a specific embodiment, when L satisfies the range of 2 / 3L'≥L≥1 / 2L', it can ensure that the components (the first body, the second body and the fuse) have enough space in the package body, and at the same time, too much space will not be wasted. This appropriate spatial distribution can help heat dissipation and prevent overheating. At the same time, having enough space can ensure that the connection between components is more stable, reduce the influence of mechanical stress, and on the other hand, reduce the manufacturing cost. If the width of the selected first body 22, the second body 23 and the fuse 3 is greater than 2 / 3 of the package body width L', the space utilization rate in the package body is reduced, which may cause heat dissipation problems, increase manufacturing costs, and may affect mechanical stability. If the width of the selected first body 22, the second body 23 and the fuse 3 is less than 1 / 2 of the package body width L', the space between the tab structures may be too compact, affecting heat dissipation, mechanical stability and assembly efficiency. Furthermore, too small a width may increase manufacturing costs because higher precision and a more complicated assembly process are required.

[0056] In addition, this design effectively plays the role of the fuse 3, ensures the mechanical strength of the pole ear, and prevents the pole ear from being torn along the length direction under the action of external force. Furthermore, in order to ensure that the fuse 3 can effectively play its protective role, the material selection of the fuse 3 is also crucial. Generally, the material of the fuse 3 should have good conductivity, appropriate melting point and high mechanical strength. The conductivity can ensure that the fuse 3 can smoothly transmit the current under normal working conditions, and the appropriate melting point can be blown in time to protect the circuit safety when the circuit is overcurrent. At the same time, the higher mechanical strength can ensure that the fuse is not easily damaged when subjected to external force, thereby maintaining the stability of the circuit.

[0057] In a specific implementation, the material of the fuse 3 can be metal or alloy materials, such as copper, aluminum, nickel, iron, etc., or their alloys. These materials have good electrical conductivity and high mechanical strength, which can meet the basic requirements of the fuse. At the same time, by adjusting the composition of the material and the processing technology, the fuse can have an appropriate melting point to meet the needs of circuit protection.

[0058] Preferably, the second part 12 is connected to a connector 121, which is symmetrical along the package body 1 and the extension body 2, and the connector 121 is electrically connected to the pole piece. The connector 121 has good conductivity and stability, and can ensure smooth transmission of current between the package body 1 and the extension body 2. At the same time, the material selection of the connector 121 has also been carefully considered, not only to ensure good electrical connection between it and the pole piece, but also to take into account its wear resistance and corrosion resistance to extend the service life of the product. In the second part 12, the connector 121 is symmetrically distributed along the package body 1 and the extension body 2, and is electrically connected to the pole piece. Through this design, the pole ear presents a "cross"-shaped structure, which effectively prevents the fragile fracture of the pole ear while reducing the use of consumables. In addition, the connector 121 is directly connected to the current collector of the pole piece, and its width is much smaller than the package body, thereby indirectly increasing the area of ​​​​active material in the material area, which helps to improve the energy density and charge and discharge performance of the battery.

[0059] It is known that the fuse 3 will melt quickly when the battery temperature rises abnormally, cut off the current, and prevent the occurrence of thermal runaway accidents. The design of the "cross"-shaped structure ear also increases the stability of the structure, improves the uniformity of current distribution, prevents local overheating caused by current concentration, and achieves the purpose of effective heat dissipation. The two have good compatibility and provide double protection for the safety of the battery. The "cross"-shaped ear structure preferentially disperses the current within a certain temperature range to avoid local high temperature. After exceeding a certain temperature range, the fuse 3 plays the role of the last safety line of defense and effectively ensures its safety.

[0060] The above description shows and describes several preferred embodiments of the utility model, but as shown above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept of this article through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A tab structure, characterized in that: The invention comprises a packaging body (1) packaged with a pole piece and an extension body (2) connected to the packaging body (1); the extension body (2) is welded with a fuse piece (3) which is fused when a current flows through the pole ear structure and is greater than or equal to a current threshold; the fuse piece (3) is spaced apart from the packaging body (1).

2. The tab structure according to claim 1, characterized in that: The extension body (2) is provided with a groove portion (21), and the fuse piece (3) is accommodated in the groove portion (21) by laser welding.

3. The tab structure according to claim 2, characterized in that: The depth of the groove portion (21) is equal to the thickness of the fuse piece (3).

4. The tab structure according to claim 2, characterized in that: The extension body (2) comprises a first body (22) and a second body (23) connected to the first body (22); the second body (23) is connected to the first body (22) via the groove portion (21); and the second body (23) is spaced between the fuse piece (3) and the packaging body (1).

5. The tab structure according to claim 4, characterized in that: The widths of the first body (22), the second body (23) and the fuse (3) are all equal. Assuming their widths are L, the width of the package (1) is L', and L and L' satisfy the relationship: 2 / 3L'≥L≥1 / 2L'.

6. The tab structure according to claim 1, characterized in that: The distance D between the fuse piece (3) and the packaging body (1) is 2-4 mm.

7. The tab structure according to claim 1, characterized in that: The width of the extension body (2) is smaller than the width of the packaging body (1).

8. The tab structure according to claim 1, characterized in that: The packaging body (1) comprises a first part (11) and a second part (12) connected to the first part (11), the first part (11) is connected to the extension body (2), and the first part (11) is coated with tab glue.

9. The tab structure according to claim 8, characterized in that: The first part (11) and the second part (12) have the same structure, and their area ratio is 1:

2.

10. The tab structure according to claim 8, characterized in that: The second portion (12) is connected to a connecting body (121), the connecting body (121) is symmetrically arranged along the packaging body (1) and the extension body (2), and the connecting body (121) is electrically connected to the electrode piece.

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