Pin connection structure of battery, top cover assembly and battery

Abstract

The utility model discloses a pin connecting structure of a battery, a top cover assembly and the battery, the pin connecting structure comprises a pole connecting part, a tab connecting part and a transition part, and the transition part is respectively connected with the pole connecting part and the tab connecting part; each of the pole connecting part, the tab connecting part and the transition part adopts at least two stacked metal layers, and at least one metal layer is a copper-aluminum composite layer. The conductivity of copper is higher than that of aluminum, and compared with a battery pin with an aluminum material as a base body, the resistance can be remarkably reduced by using a metal layer containing a copper material as a conductive material of the battery pin in the embodiment of the invention. The copper-aluminum composite layer is used in the battery pin, so that the charging and discharging efficiency of the battery can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a pin connection structure of a battery, a top cover component and a battery. Background Art

[0002] Lithium-ion battery is a rechargeable battery with advantages such as high energy density and long cycle life. It is widely used in portable electronic devices and electric vehicles. The basic charging and discharging structure of lithium-ion battery is a core pack with positive and negative pole ears, but the energy of a single core pack is not large. In practice, several core packs are often connected in parallel to form a single battery cell according to the needs of use. Therefore, "battery pins" are needed to connect the pole ears of each core pack to the pole of a single battery cell, so that a single battery cell has a unified external electrode, which can improve the load capacity of the core pack and facilitate the assembly of the core pack.

[0003] In current battery design, the internal resistance of the battery is one of the key factors affecting battery performance. For example, the internal resistance of the battery includes the positive electrode resistance (R 正极 )、Core resistance (R 芯包 ) and the negative electrode resistance (R 负极 ), these resistors are related to each other through an equivalent circuit model. During high current charging and discharging, the heat concentration caused by the internal resistance of the battery will significantly reduce the performance of the battery, especially in a high temperature environment. Therefore, reducing the internal resistance of the battery is crucial to improving battery performance. In the prior art, aluminum pins are used and their flow area is increased to reduce the internal resistance of the battery. Although increasing the flow area of ​​the pins can reduce the internal resistance of the battery, it will also lead to a reduction in the internal space of the battery cell, which will sacrifice the capacity of the battery cell.

[0004] Therefore, the prior art still needs to be improved and developed. Utility Model Content

[0005] The main purpose of the utility model is to provide a battery pin connection structure, a top cover assembly and a battery, aiming to solve the problem that although increasing the flow area of ​​the pin can reduce the internal resistance of the battery, it will also lead to a reduction in the internal space of the battery cell and sacrifice the capacity of the battery cell.

[0006] To achieve the above-mentioned purpose, the utility model proposes a pin connection structure of a battery, including a pole connection part, a pole tab connection part and a transition part, wherein the transition part connects the pole connection part and the pole tab connection part respectively; the pole connection part, the pole tab connection part and the transition part all use at least two stacked metal layers, and at least one metal layer is a copper-aluminum composite layer.

[0007] In an optional implementation manner of the present application, all of the metal layers are copper-aluminum composite layers, and the thickness of each metal layer is the same.

[0008] In an optional implementation manner of the present application, the pole connecting portion, the pole lug connecting portion and the transition portion jointly define at least one first notch; and / or

[0009] The transition portion is provided with at least one second notch, and the transition portion and the tab connecting portion jointly define the second notch.

[0010] In an optional embodiment of the present application, the pole lug connection portion includes a first pole lug connection part, an intermediate connection part and a second pole lug connection part connected in sequence, and the pin connection structure also includes a bending hole arranged at the connection between the first pole lug connection part and the intermediate connection part and / or a bending hole arranged at the connection between the second pole lug connection part and the intermediate connection part.

[0011] In an optional embodiment of the present application, the transition portion is spaced apart from or flexibly connected to at least two adjacent metal layers of the pole tab connection portion, so that the transition portion is flexibly connected to the pole tab connection portion.

[0012] In an optional embodiment of the present application, the transition portion includes a transition part and a flexible part connected in sequence, and at least two adjacent metal layers of the flexible part are spaced apart or flexibly connected; one end of the transition part away from the flexible part is connected to the pole connecting part, and one end of the flexible part away from the transition part is flexibly connected to the pole ear connecting part.

[0013] In an optional embodiment of the present application, the pole lug connection portion includes a first pole lug connection portion, an intermediate connection portion and a second pole lug connection portion which are connected in sequence, and the same end of the first pole lug connection portion, the intermediate connection portion and the second pole lug connection portion is connected to an end of the flexible portion away from the transition portion; the first pole lug connection portion and the second pole lug connection portion are both bendably connected to the intermediate connection portion, so that the first pole lug connection portion and the second pole lug connection portion can be bent with the intermediate connection portion, and the first pole lug connection portion and the second pole lug connection portion can overlap with the intermediate connection portion; wherein the flexible portion can deform following the bending or flattening of the first pole lug connection portion and the second pole lug connection portion relative to the intermediate connection portion.

[0014] In an optional embodiment of the present application, the pin connection structure can switch between a flattened state and a bent state according to the flexible connection between the flexible part and the pole lug connection portion; when the pin connection structure is in the flattened state, the flexible part and the pole lug connection portion are located on the same preset plane or are approximately parallel, and both are bent together with the pole connection portion; when the pin connection structure is in the bent state, at least a portion of the flexible part and at least a portion of the pole lug connection portion are deformed.

[0015] In an optional embodiment of the present application, the total length of the transition portion is l1, the length of the flexible portion is l2, l1 and l2 satisfy: 0.2≤l2 / l1≤0.9 and / or; the thickness of the flexible portion is t1, the thickness of the metal layer is t2; t1 and t2 satisfy 0.1≤t2 / t1≤0.5; and / or when the pin connection structure is in a flattened state, the width value of the pole ear connection portion is equal to the width value of the transition portion; and / or when the pin connection structure is in a flattened state, the width value of the pole connection portion is equal to the width value of the transition portion.

[0016] The utility model also provides a top cover assembly, which comprises the pin connection structure, pole and pole ear of the battery as described above, wherein the pole is connected to the pole connection part; and the pole ear is connected to the pole ear connection part through a fixing layer.

[0017] In an optional embodiment of the present application, the fixed layer is an aluminum layer, and the pole lug is welded to the fixed layer; wherein the thickness of the fixed layer is t3, the sum of the thicknesses of the pole lug connecting portion and the fixed layer is t4, t3 and t4 satisfy: 0.1≤t3 / t4≤0.8; and / or the length of the fixed layer is l3, the width of the fixed layer is w1, l3 and w1 satisfy: 0.15≤w1 / l3≤0.95.

[0018] In an optional embodiment of the present application, the top cover assembly also includes a top cover sheet and a lower plastic part arranged between the top cover sheet and the pole connecting portion, and the pin, the top cover sheet and the lower plastic are connected through the pole; wherein the width value of the transition portion is w2, the width value of the top cover sheet is w3, and w2 and w3 satisfy: 0.4≤w2 / w3≤0.9.

[0019] The utility model also provides a battery, comprising a core pack and the top cover assembly as described above, wherein the pole ear comprises a bending edge and a welding portion, the welding portion can be bendably arranged on the bending edge, the bending edge is connected to the core pack, and the welding portion is connected to the pole ear connecting portion.

[0020] In order to achieve the above-mentioned purpose, the utility model provides a battery pin connection structure, which includes:

[0021] Pole connection part;

[0022] a tab connection portion; and

[0023] A transition portion, the transition portion connecting the pole connecting portion and the pole lug connecting portion;

[0024] Wherein, the transition portion is flexibly connected to the tab connection portion, so that the pin connection structure can be switched between a flattened state and a bent state;

[0025] The pin connection structure is in a flattened state, the transition portion and the pole lug connection portion are located on the same preset plane or are substantially parallel, and both are bent together with the pole connection portion;

[0026] When the pin connection structure is in a bent state, at least a portion of the transition portion and at least a portion of the tab connection portion are deformed.

[0027] In an optional implementation manner of the present application, the transition portion can deform following the deformation of the tab connecting portion.

[0028] In an optional embodiment of the present application, the transition portion includes a transition part and a flexible part connected in sequence, one end of the transition part away from the flexible part is connected to the pole connecting part, and one end of the flexible part away from the transition part is flexibly connected to the pole lug connecting part;

[0029] The tab connection portion includes a first tab connection portion, an intermediate connection portion, and a second tab connection portion which are connected in sequence, wherein the same end of the first tab connection portion, the intermediate connection portion, and the second tab connection portion is connected to an end of the flexible portion away from the transition portion;

[0030] The first tab connection portion and the second tab connection portion are both bendably connected to the middle connection portion, so that the first tab connection portion and the second tab connection portion can be bent with the middle connection portion, and the first tab connection portion and the second tab connection portion can overlap with the middle connection portion;

[0031] The flexible portion can be deformed following the bending or flattening of the first tab connecting portion and the second tab connecting portion relative to the middle connecting portion.

[0032] In an optional implementation manner of the present application, the total length of the transition portion is l1, the length of the flexible portion is l2, l1 and l2 satisfy: 0.2≤l2 / l1≤0.9 and / or;

[0033] When the pin connection structure is in a flattened state, the width of the tab connection portion is equal to the width of the transition portion; and / or

[0034] When the pin connection structure is in a flattened state, the width of the pole connection portion is equal to the width of the transition portion.

[0035] The pole connecting part of the utility model can provide electrical connection, and the pole ear connecting part can be connected to the pole ear of the battery. The pole ear is usually a part of the internal electrode of the battery and is used for external connection; the transition part connects the pole connecting part and the pole ear connecting part to ensure the continuity and stability of the electrical connection.

[0036] The pole connection part, the pole ear connection part and the transition part all use at least two stacked metal layers, at least one of which is a copper-aluminum composite layer. The electrical conductivity of copper is higher than that of aluminum. Compared with the battery pins with aluminum as the substrate, the embodiment of the present application uses a copper-containing metal layer as the conductive material of the battery pin, which can significantly reduce the resistance of the battery. Using a copper-aluminum composite layer in the battery pin can improve the charging and discharging efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0038] Figure 1 It is a schematic diagram of the structure of the battery in the embodiment of the present application;

[0039] Figure 2 Another structural schematic diagram of a battery in an embodiment of the present application;

[0040] Figure 3 This is a schematic diagram of the assembly of the top cover assembly in the embodiment of the present application;

[0041] Figure 4 for Figure 3 Enlarged view of part A in the middle;

[0042] Figure 5 It is a schematic assembly diagram of the pin connection structure in the embodiment of the present application in a bent state;

[0043] Figure 6 This is a structural schematic diagram of the pin connection structure in the intermediate state in the embodiment of the present application;

[0044] Figure 7 It is an assembly schematic diagram of the pin connection structure in the intermediate state in the embodiment of the present application;

[0045] Figure 8 This is a structural schematic diagram of the pin connection structure in the intermediate state in the embodiment of the present application;

[0046] Fig. 9 It is a schematic assembly diagram of the pin connection structure in the embodiment of the present application in a flattened state;

[0047] Fig.10 This is a schematic structural diagram of the pin connection structure in the embodiment of the present application in a flattened state;

[0048] Fig.11 for Fig.10 Enlarged view of part B in the middle.

[0049] Description of Figure Numbers:

[0050]

[0051]

[0052] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use. All other embodiments obtained by those skilled in the art without creative work based on the embodiments in the present application belong to the scope of protection of the present application.

[0054] Reference to "embodiment" or "implementation" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment or implementation may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] With the development of fast charging technology, batteries need to withstand greater currents. In the battery production process, battery assembly is a key link, which is related to the quality of the finished battery. Every detail in the battery assembly process, including the flattening and bending of the pins, may affect the performance and safety of the final product. The existing pin structure uses aluminum as the base and increases its flow area to reduce the internal resistance of the battery. Although increasing the flow area of ​​the pin can reduce the internal resistance of the battery, it will also lead to a reduction in the internal space of the battery cell, which will sacrifice the capacity of the battery cell.

[0056] To solve the above problems, please refer to Fig. 9 , Fig.10 and Fig.11 The present application proposes a pin connection structure 23b of a battery 1b, comprising a pole connection portion 231b, a pole tab connection portion 232b and a transition portion 233b, wherein the transition portion 233b connects the pole connection portion 231b and the pole tab connection portion 232b respectively; the pole connection portion 231b, the pole tab connection portion 232b and the transition portion 233b all adopt at least two stacked metal layers 234b, and at least one metal layer 234b is a copper-aluminum composite layer.

[0057] In this embodiment, the pole connection portion 231b can provide electrical connection, and the tab connection portion 232b can be connected to the tab 22b of the battery 1b. The tab 22b is usually a part of the internal electrode of the battery 1b and is used for external connection; the transition portion 233b connects the pole connection portion 231b and the tab connection portion 232b to ensure the continuity and stability of the electrical connection.

[0058] The pole connection part 231b, the pole ear connection part 232b and the transition part 233b all use at least two layers of stacked metal layers 234b, at least one metal layer 234b is a copper-aluminum composite layer. The electrical conductivity of copper is higher than that of aluminum. Compared with the battery 1b pin with aluminum as the substrate, the embodiment of the present application uses a copper-containing metal layer 234b as the conductive material of the battery 1b pin, which can significantly reduce the resistance of the battery 1b. The use of a copper-aluminum composite layer in the battery 1b pin can improve the charge and discharge efficiency of the battery 1b. Due to the reduction in the resistance of the battery 1b, the energy conversion efficiency of the battery 1b during the charge and discharge process is improved, which means that the battery 1b can be charged and discharged faster while reducing energy loss.

[0059] Exemplarily, the pole connection portion 231b and the transition portion 233b are bent to each other, that is, the pole connection portion 231b and the transition portion 233b are arranged at an angle. In some embodiments, the angle between the pole connection portion 231b and the transition portion 233b can be 90 degrees, that is, in an ideal state, the angle between the pole connection portion 231b and the transition portion 233b is 90 degrees. Affected by the process accuracy, the angle between the pole connection portion 231b and the transition portion 233b can be about 90 degrees, such as 89 degrees, 91 degrees, etc. The angle between the pole connection portion 231b and the transition portion 233b can be achieved by a single bending process. The angle between the pole connection portion 231b and the transition portion 233b can be set as needed, and the utility model does not limit the angle between the pole connection portion 231b and the transition portion 233b.

[0060] For example, in one implementation of the embodiment of the present application, all metal layers 234b are copper-aluminum composite layers, and the thickness of each metal layer 234b is the same. Since the thickness of each metal layer 234b is the same, this ensures that the entire pin connection structure 23b has uniform conductivity in each part, which helps to evenly distribute the current. And the uniform thickness of the metal layer 234b can simplify the manufacturing process, and standardized processes can be used to manufacture all copper-aluminum composite layers, reducing production complexity and potential inconsistencies.

[0061] In actual applications, all metal layers 234b are copper-aluminum composite layers, that is, after the current medium is changed to copper-aluminum composite material, since the electrical conductivity of copper is higher than that of aluminum, this means that the pins using copper-aluminum composite material can provide lower resistance than the pins using pure aluminum material, thereby helping to reduce the internal resistance of battery 1b. The internal resistance of pure copper pins used in batteries is about 0.09mΩ in actual measurements, and the internal resistance of pure aluminum pins used in batteries is about 0.14mΩ in actual measurements. Therefore, in this embodiment, the internal resistance of the copper-aluminum composite layer used in battery 1b is 0.02mΩ, so the internal resistance of battery 1b can be reduced by 21.4%.

[0062] In other optional embodiments, the at least two metal layers 234b are not limited to all metal layers 234b being copper-aluminum composite layers, such as at least one metal layer 234b being a copper-aluminum composite layer, at least one metal layer 234b being a copper layer or an aluminum layer.

[0063] In other optional embodiments, at least two metal layers 234b are not limited to all metal layers 234b having the same thickness, such as at least two metal layers 234b having the same thickness, wherein the thickness of one metal layer 234b is greater than or less than the thickness of the other metal layers 234b.

[0064] Exemplarily, the flattening and bending process of the pin connection structure 23b of the battery 1b plays an important role in the assembly process of the battery 1b. In battery manufacturing, if the battery pin is bent or deformed in the previous process, the flattening process can restore the pin connection structure 23b to its original flat state to facilitate subsequent assembly or welding; the bending process is more related to the formation of the internal structure of the battery 1b, especially in the wound battery cell, the bending process of the pin connection structure 23b is used to ensure the shell state of the battery pin connection structure 23b, and ensure the overall structural stability of the battery 1b and the reliability of the electrical connection. That is, the pin connection structure 23b has a flattened state and a bent state, and is in an intermediate state before achieving a fully bent state after bending.

[0065] In this regard, the embodiment of the present application sets a prefabricated notch on the pin connection structure, and the prefabricated notch facilitates the bending process of the tab connection part. Figures 2 to 6 In another implementation of the embodiment of the present application, the pole connection portion 231a and the pole lug connection portion 232a and the transition portion 233a jointly define at least one first notch 2333a. Exemplarily, the pole connection portion 231a and the pole lug connection portion 232a and the two sides of the transition portion 233a jointly define two first notches 2333a, and the two first notches 2333a are located on both sides of the transition portion 233a. The two notches 2333a in the embodiment of the present application facilitate the bending and forming of the transition portion 233a relative to the pole connection portion 231a. It should be understood that the first notches 2333a in the embodiment of the present application are taken as two as an example, and the number of the first notches 2333a can also be designed to be one, which will not be illustrated one by one here.

[0066] It should be noted that the shape and size of the first notch 2333a are not limited in the embodiment of the present application, and the shape and size of the first notch 2333a can be set according to actual needs.

[0067] Exemplarily, the transition portion 233a is provided with at least one second notch 2334a, and the transition portion 233a and the pole ear connection portion 232a jointly define the second notch 2334a. Exemplarily, the transition portion 233a is provided with two second notches 2334a on both sides thereof, that is, a second notch 2334a is provided on one side of the transition portion 233a, and a second notch 2334a is provided on the other side of the transition portion 233a. The second notch 2334a of the embodiment of the present application is jointly defined by the transition portion 233a and the pole ear connection portion 232a, which is conducive to the deformation of the pole ear connection portion 232a relative to the excess portion 233a. Or it can be understood that during the deformation of the pole ear connection portion 232a relative to the transition portion 233a, the design of the second notch 2334a can reduce resistance, which is more conducive to the deformation of the pole ear connection portion 232a. It should be understood that the embodiment of the present application takes two second notches 2334a as an example, and the number of second notches 2334a can also be designed to be one, which will not be illustrated one by one here.

[0068] It should be noted that the shape and size of the second notch 2334a are not limited in the embodiment of the present application, and the shape and size of the second notch 2334a can be set according to actual needs.

[0069] In the embodiment of the present application, at least one first notch 2333a and at least one second notch 2334a are provided to define the size of the tab connection portion 232a that needs to be connected to the tab 22a, and more positioning points can be provided, thereby improving the positioning accuracy when assembling the tab 22a, reducing assembly errors, and adapting to more diverse battery design and assembly requirements. And by accurately defining the size of the first notch 2333a and the second notch 2334a, the cutting and forming of the pin structure can be accurately controlled, and then through an automated or semi-automated assembly process, the production efficiency is improved and the manufacturing process is simplified.

[0070] Exemplarily, the first notch 2333a and the second notch 2334a are connected, and the first notch 2333a and the second notch 2334a located on the same side of the pin connection structure 23a are connected. The distance between the two first notches 2333a is greater than the distance between the two second notches 2334a.

[0071] In other optional embodiments, the transition portion 233a has no notch.

[0072] Exemplarily, the spacing between the two second notches 2334a is smaller than the width of the tab connection portion 232a. That is, whether the tab connection portion 232a is in a flattened state, an intermediate state, or a bent state, the spacing between the two second notches 2334a is smaller than the width of the tab connection portion 232a. In other optional embodiments, the spacing between the two second notches 2334a is equal to the width of the tab connection portion 232a in the bent state.

[0073] Exemplarily, the distance between the two first notches 2333a is smaller than the width of the tab connection portion 232a in the unfolded state. Exemplarily, the distance between the two first notches 2333a is equal to the width of the tab connection portion 232a in the bent state.

[0074] The transition portion 233a of the embodiment of the present application includes a first transition portion 2331a and a second transition portion 2332a connected to each other, wherein one end of the first transition portion 2331a away from the second transition portion 2332a is connected to the pole connecting portion 231a, and one end of the second transition portion 2332a away from the first transition portion 2331a is connected to the pole lug connecting portion 232a. The two first notches 2333a are located on both sides of the first transition portion 2331a, and the two second notches 2334a are located on both sides of the second transition portion 332a.

[0075] Illustratively, the pole lug connection portion 232a disclosed in this embodiment includes a first pole lug connection portion 2321a, an intermediate connection portion 2323a and a second pole lug connection portion 2322a which are connected in sequence. The first pole lug connection portion 2321a and the second pole lug connection portion 2322a are both bent from the intermediate connection portion 2323a, and the bending directions are opposite. The bent portions are used to provide additional surface area for fixed connection with the pole lug 22a, thereby increasing the stability and reliability of the connection.

[0076] For example, Figure 2 , Figure 3 and Figure 4 As shown, the pin connection structure 23a is in an intermediate state before the bent state is fully realized after bending. The pin connection structure 23a disclosed in this embodiment also includes a bending hole 2324a provided at the connection between the first pole ear connection part 2321a and the middle connection part 2323a, and a bending hole 2324a provided at the connection between the second pole ear connection part 2322a and the middle connection part 2323a. The bending hole 2324a is provided along the length direction of the middle connection part 2323a, and at least one bending hole 2324a is provided. The bending hole 2324a can be used as a reference point for positioning the pole ear connection part 232a in the intermediate state and the bent state, so as to ensure accurate alignment during the assembly process of the battery 1a.

[0077] It is understandable that the bending hole 2324a can reduce the length required for bending, thereby reducing the force required for bending, and the prefabricated bending hole 2324a provides a precise positioning point for bending, which helps to achieve a consistent bending angle and shape, and facilitates subsequent welding with a tab 22a of uniform size, which is crucial to ensuring product quality and reliability. And by adjusting the position of the bending hole 2324a, the pin connection structure 23a can be customized according to different battery 1a design requirements.

[0078] In an optional manner, in order to achieve the bending effect, a prefabricated notch is provided as in the above embodiment. However, due to the presence of this prefabricated notch, a weak area of ​​overcurrent will be formed on the structure of the pin. In the application scenario of fast charging and high current, the demand for fast charging and high current cannot be met.

[0079] In this regard, the present application satisfies the requirement that the pin connection structure does not exceed the assembly space. By setting a flexibly connected transition portion 233b and a pole ear connection portion 232b, during the ultrasonic welding process, the pin connection structure 23b is allowed to weld the pole ear 22b in an intermediate state without setting a prefabricated notch, and to enter the shell in a bent state, thereby achieving rapid switching of the pin connection structure 23b between a flattened state and a bent state, and also improving the deformation capacity of the connection between the transition portion 233b and the pole ear connection portion 232b, thereby reducing the occurrence of breakage of the pin connection structure 23b during the production, transportation and assembly of the battery 1b, which is beneficial to ensuring the working reliability of the pin of the battery 1b.

[0080] Please refer to Figure 7 , Figure 8 , Fig. 9 and Fig.10 In another implementation of the embodiment of the present application, the transition portion 233b is spaced apart from or flexibly connected to at least two adjacent metal layers 234b of the tab connection portion 232b, so that the transition portion 233b is flexibly connected to the tab connection portion 232b. This helps to adapt to the bending and flattening process, and at least part of the transition portion 233b is flexibly connected to the tab connection portion 232b, so that the pin connection structure 23b can switch between the flattened state and the bent state.

[0081] Furthermore, the flexible connection can reduce material fatigue caused by mechanical stress caused by repeated bending actions of the tab connection portion 232b, thereby extending the service life of the pin connection structure 23b of the battery 1b.

[0082] Exemplarily, at least two adjacent metal layers 234b of the pole connection portion 231b disclosed in this embodiment are rigidly connected; at least two adjacent metal layers 234b of the pole ear connection portion 232b are rigidly connected, and the at least two rigidly connected metal layers 234b are made, which provides the strength and stability required for connection with other structures.

[0083] Exemplarily, in one implementation of the embodiment of the present application, the transition portion 233b includes a transition portion 2331b and a flexible portion 2332b connected in sequence, and at least two adjacent metal layers 234b of the flexible portion 2332b are spaced apart or flexibly connected, that is, there is a gap layer between at least two adjacent metal layers 234b, so that the flexible portion 2332b has the ability to bend and deform, and the flexible portion 2332b can also serve as a stress buffer to disperse the stress caused by volume changes or mechanical impacts during the charging and discharging process of the battery 1b, thereby reducing stress concentration at the connection point.

[0084] Exemplarily, the end of the transition portion 2331b disclosed in this embodiment away from the flexible portion 2332b is connected to the pole connection portion 231b, and the fixed connection between the transition portion 2331b and the pole connection portion 231b provides a stable electrical and mechanical connection point, which helps to maintain the stability of the entire battery 1b system. The end of the flexible portion 2332b away from the transition portion 2331b is flexibly connected to the pole lug connection portion 232b, and the flexible portion 2332b can deform as the pole lug connection portion 232b is displaced during the bending process, and can still maintain the integrity of the connection.

[0085] Therefore, the pin connection structure 23b disclosed in this embodiment can be switched between a flattened state and a bent state according to the flexible connection between the flexible portion 2332b and the tab connection portion 232b; the pin connection structure 23b is in a flattened state, such as Figure 8 In the pin connection structure 23b shown, the flexible portion 2332b and the pole tab connection portion 232b are located on the same preset plane or are roughly parallel, and both are bent together with the pole connection portion 231b; when the pin connection structure 23b is in a bent state, at least a portion of the flexible portion 2332b and at least a portion of the pole tab connection portion 232b are deformed.

[0086] In actual use, the design of the flexible portion 2332b makes it unnecessary to set a prefabricated notch in the pin connection structure 23b, which optimizes the connection method of the pin and reduces the structural weaknesses caused by the prefabricated notch. It also reduces the weak area, improves the current carrying capacity of the pin, and meets the needs of fast charging and high current. Compared with the solution of setting a prefabricated notch, through actual calculations, the ratio of the width of the overcurrent weak area to the width of the prefabricated notch in this embodiment is 1:2.5. Therefore, this embodiment can increase the overcurrent rate by about 150% based on the existing technology.

[0087] Since there is no need to set a prefabricated notch, it is understandable that when the pin connection structure 23b is in a flattened state, the width value of the pole ear connection portion 232b is equal to the width value of the transition portion 233b, and the width value of the pole connection portion 231b is equal to the width value of the transition portion 233b. By ensuring that the width of each part is the same, the equal width design helps to achieve uniform current flow in the connecting part, especially in fast charging and high current application scenarios, it can withstand a larger current, improve the use efficiency of the battery 1b, and avoid the reduction of the flow area due to the sudden reduction of the width.

[0088] Exemplarily, the tab connection portion 232b disclosed in this embodiment includes a first tab connection portion 2321b, an intermediate connection portion 2323b and a second tab connection portion 2322b connected in sequence, and the same end of the first tab connection portion 2321b, the intermediate connection portion 2323b and the second tab connection portion 2322b is connected to an end of the flexible portion 2332b away from the transition portion, which can maintain the connection state and adapt to the need for the tab connection portion 232b to rotate. The first tab connection portion 2321b and the second tab connection portion 2322b are both bendably connected to the intermediate connection portion 2323b, so that the first tab connection portion 2321b and the second tab connection portion 2322b can be bent with the intermediate connection portion 2323b, driving the flexible portion 2332b to deform autonomously, realizing that the pin connection structure 23b is in an intermediate state, and facilitating welding of the tab 22b on the first tab connection portion 2321b and the second tab connection portion 2322b.

[0089] The first tab connection portion 2321b and the second tab connection portion 2322b can overlap with the middle connection portion 2323b to achieve a bent state of the pin connection structure 23b, making it easier for the pin connection structure 23b of the battery 1b to fit into the shell.

[0090] The flexible portion 2332b can be deformed following the bending or flattening of the first tab connection portion 2321b and the second tab connection portion 2322b relative to the middle connection portion 2323b.

[0091] Illustratively, the present embodiment discloses that the first pole tab connection portion 2321b, the middle connection portion 2323b and the second pole tab connection portion 2322b are integrally formed, which can reduce the potential risk of connection point breakage and improve the reliability of the battery 1b.

[0092] For example, in one implementation of the embodiment of the present application, the total length of the transition portion 233b is l1, and the length of the flexible portion 2332b is l2, and l1 and l2 satisfy: 0.2≤l2 / l1≤0.9. By setting the range of the length ratio, it can be ensured that the flexible portion 2332b has sufficient length to provide the required flexibility, but is not too long to affect the stability of the overall structure.

[0093] In an optional embodiment of the present application, at least two adjacent metal layers 234b are first welded to each other to form a transition portion 2331b, which has the characteristics of high strength and easy CNC processing; while the unwelded portion remains in its original state to form a flexible portion 2332b, which can remain soft to facilitate deformation.

[0094] Exemplarily, all metal layers 234b are copper-aluminum composite layers, and the multiple layers of copper-aluminum composite layers are connected by low-temperature brazing. Compared with traditional welding, low-temperature brazing generates less heat, has a small heat-affected zone on the copper-aluminum composite material, prevents the copper in the copper-aluminum composite layer from melting, and helps to protect the original properties of the material.

[0095] Exemplarily, the metal layers 234b of the flexible portion 2332b of the embodiment of the present application are described by way of example by being spaced apart from each other, so that a gap 235b is formed between two adjacent metal layers 234b. In particular, when the pin connection structure 23b is in a flattened state, the two adjacent metal layers 234b are separated by the gap 235b. When the pin connection structure 23b is in an intermediate state and a bent state, it can be understood that at least the portion of the flexible portion 2332b connected to the tab connection portion 232b is deformed, and therefore the gap 235b between the metal layers 234b where the flexible portion 2332b is deformed also changes accordingly.

[0096] In one implementation of the embodiment of the present application, the thickness of the flexible portion 2332b is t1, and the thickness of the metal layer 234b is t2; t1 and t2 satisfy 0.1≤t2 / t1≤0.5. By setting the thickness ratio of the metal layer 234b to the flexible portion 2332b, the mechanical properties of the overall structure, including its flexibility and strength, can be optimized. The optimization of the thickness ratio can reduce the use of thicker materials, thereby reducing material costs without sacrificing performance.

[0097] The technical solution of the utility model also proposes a top cover assembly 20b, including the pin connection structure 23b, the pole 21b and the pole ear 22b of the above battery 1b; the pole 21b is connected to the pole connecting part 231b; the pole ear 22b is connected to the pole ear connecting part 232b through a fixing layer, and the pole ear 22b is fixedly connected to the pole ear connecting part 232b through the fixing layer. The setting of the fixing layer enhances the mechanical strength of the pole ear connecting part 232b, so that the entire top cover assembly 20b can withstand greater mechanical stress.

[0098] Exemplarily, the pole connecting portion 231b disclosed in this embodiment is provided with a fixing hole 2311b, and the pole 21b is fixedly connected to the pole connecting portion 231b through the fixing hole 2311b; by fixing the pole 21b to the pole connecting portion 231b through the fixing hole 2311b, the structural stability of the assembly is enhanced and loosening or displacement during use is reduced.

[0099] For example, in one implementation of the embodiment of the present application, the fixed layer is an aluminum layer, and the tab 22b is welded to the fixed layer; aluminum generally has good weldability and can form a high-quality welded joint. The oxide layer formed when aluminum is welded can be effectively removed under a proper welding process, thereby ensuring the formation of a good weld, and aluminum is relatively cheap, which can reduce the manufacturing cost of the battery 1b on the basis of ensuring a strong weld.

[0100] Among them, the thickness of the fixed layer is t3, the sum of the thickness of the pole ear connection part 232b and the fixed layer is t4, t3 and t4 satisfy: 0.1≤t3 / t4≤0.8. By setting the thickness ratio of the fixed layer, the use of materials can be reduced and the rational use of materials can be achieved while ensuring the structural strength and electrical performance.

[0101] Exemplarily, the length of the fixed layer is l3, the width of the fixed layer is w1, l3 and w1 satisfy: 0.15≤w1 / l3≤0.95; the ratio of the width to the length of the fixed layer affects its electrical properties, and an appropriate ratio helps to reduce resistance and improve the charge and discharge efficiency of battery 1b.

[0102] It should be noted that the area of ​​the fixing layer needs to be larger than the actual welding area. This ratio range provides design flexibility and the size of the fixing layer can be adjusted according to the specific needs of the battery 1b to meet different design requirements.

[0103] Exemplarily, in one implementation of the embodiment of the present application, the top cover assembly 20b also includes a top cover sheet and a lower plastic part arranged between the top cover sheet and the pole connecting portion 231b. The pins, the top cover sheet and the lower plastic are connected through the pole 21b to form a stable structure, which helps to improve the mechanical stability of the top cover assembly 20b.

[0104] The width of the top cover sheet needs to be greater than the unfolded width of the pin connection structure 23b. Some space margin should be left in the design, otherwise there will be a risk of cutting the insulating film when entering the shell. Therefore, the width value of the transition portion 233b is w2, and the width value of the top cover sheet is w3. w2 and w3 satisfy: 0.4≤w2 / w3≤0.9. The appropriate width ratio can simplify the assembly process, improve production efficiency, and reduce assembly time.

[0105] See also Figure 1 , Figure 2 and Figure 5 The utility model also provides a battery 1a, including a core pack 10a and a top cover assembly 20a as described in the above embodiment, wherein the pole tab 22a includes a bending edge 221a and a welding portion 222a, wherein the welding portion 222a is bendably disposed on the bending edge 221a, and the bending edge 221a is connected to the core pack 10a. The design of the bending edge 221a can enhance the connection strength between the pole tab 22a and the core pack 10a, and reduce connection failures caused by mechanical vibration or impact. The welding portion 222a is connected to the pole tab connection portion 232a, and the stable connection between the welding portion 222a and the pole tab connection portion 232a helps to prevent safety problems caused by poor connection during use of the battery 1a.

[0106] The battery of the embodiment of the present application may be a lithium battery, which is a lithium-based rechargeable battery widely used in portable electronic devices, power tools, electric vehicles, energy storage systems and other fields. Lithium batteries have become the preferred power supply solution in modern electronic devices due to their high energy density, low self-discharge rate, long life and good temperature adaptability. The lithium battery includes a top cover assembly. In the structure of the lithium battery, the top cover assembly is a key part. It is located at the top of the lithium battery and plays a role in connecting the internal and external circuits of the battery and ensuring the sealing and safety of the battery.

[0107] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A pin connection structure of a battery, characterized in that: include: Pole connection part; Tab connection part; as well as A transition portion, wherein the transition portion is connected to the pole connecting portion and the pole lug connecting portion respectively; The pole connecting portion, the pole lug connecting portion and the transition portion all use at least two stacked metal layers, and at least one metal layer is a copper-aluminum composite layer.

2. The pin connection structure of a battery according to claim 1, characterized in that: All the metal layers are copper-aluminum composite layers, and the thickness of each metal layer is the same.

3. The pin connection structure of a battery according to claim 2, characterized in that: The pole connecting portion, the pole lug connecting portion and the transition portion together define at least one first notch; and / or The transition portion is provided with at least one second notch, and the transition portion and the tab connecting portion jointly define the second notch.

4. The pin connection structure of a battery according to claim 3, characterized in that: The tab connection portion includes a first tab connection portion, an intermediate connection portion and a second tab connection portion which are connected in sequence, and the pin connection structure also includes a bending hole arranged at the connection between the first tab connection portion and the intermediate connection portion and / or a bending hole arranged at the connection between the second tab connection portion and the intermediate connection portion.

5. The pin connection structure of a battery according to claim 2, characterized in that: The transition portion is spaced apart from or flexibly connected to at least two adjacent metal layers of the tab connection portion, so that the transition portion is flexibly connected to the tab connection portion.

6. The pin connection structure of a battery according to claim 5, characterized in that: The transition portion comprises a transition part and a flexible part connected in sequence, and at least two adjacent metal layers of the flexible part are arranged at intervals or flexibly connected; One end of the transition portion away from the flexible portion is connected to the pole connecting portion, and one end of the flexible portion away from the transition portion is flexibly connected to the pole lug connecting portion.

7. The pin connection structure of a battery according to claim 6, characterized in that: The tab connection portion includes a first tab connection portion, an intermediate connection portion, and a second tab connection portion which are connected in sequence, wherein the same end of the first tab connection portion, the intermediate connection portion, and the second tab connection portion is connected to an end of the flexible portion away from the transition portion; The first tab connection portion and the second tab connection portion are both bendably connected to the middle connection portion, so that the first tab connection portion and the second tab connection portion can be bent with the middle connection portion, and the first tab connection portion and the second tab connection portion can overlap with the middle connection portion; The flexible portion can be deformed following the bending or flattening of the first tab connecting portion and the second tab connecting portion relative to the middle connecting portion.

8. The pin connection structure of a battery according to claim 6, characterized in that: The pin connection structure can be switched between a flattened state and a bent state according to the flexible connection between the flexible portion and the tab connection portion; The pin connection structure is in a flattened state, the flexible portion and the pole lug connection portion are located on the same preset plane or are substantially parallel, and both are bent together with the pole connection portion; When the pin connection structure is in a bent state, at least a portion of the flexible portion and at least a portion of the tab connection portion are deformed.

9. The pin connection structure of a battery according to claim 6, characterized in that: The total length of the transition portion is l1, the length of the flexible portion is l2, l1 and l2 satisfy: 0.2≤l2 / l1≤0.9 and / or; The thickness of the flexible portion is t1, the thickness of the metal layer is t2; t1 and t2 satisfy 0.1≤t2 / t1≤0.5; and / or When the pin connection structure is in a flattened state, the width of the tab connection portion is equal to the width of the transition portion; and / or When the pin connection structure is in a flattened state, the width of the pole connection portion is equal to the width of the transition portion.

10. A top cover assembly, characterized in that: The top cover assembly comprises: The pin connection structure of a battery as claimed in any one of claims 1 to 7; a pole connected to the pole connecting portion; and The pole tab is connected to the pole tab connecting portion through a fixing layer.

11. The top cover assembly according to claim 10, characterized in that: The fixed layer is an aluminum layer, and the pole tab is welded to the fixed layer; The thickness of the fixing layer is t3, the sum of the thickness of the tab connection portion and the fixing layer is t4, and t3 and t4 satisfy: 0.1≤t3 / t4≤0.8; and / or The length of the fixed layer is l3, the width of the fixed layer is w1, and l3 and w1 satisfy: 0.15≤w1 / l3≤0.

95.

12. The top cover assembly according to claim 10, characterized in that: The top cover assembly also includes a top cover sheet and a lower plastic part arranged between the top cover sheet and the pole connecting portion, and the pin, the top cover sheet and the lower plastic are connected through the pole; The width of the transition portion is w2, the width of the top cover sheet is w3, and w2 and w3 satisfy: 0.4≤w2 / w3≤0.

9.

13. A battery, characterized in that: include: Core package; as well as According to the top cover assembly as described in any one of claims 10-12, the pole ear includes a bending edge and a welding portion, the welding portion can be bendably arranged on the bending edge, the bending edge is connected to the core package, and the welding portion is connected to the pole ear connecting portion.

14. A pin connection structure of a battery, characterized in that: include: Pole connection part; Tab connection part; as well as A transition portion, the transition portion connecting the pole connecting portion and the pole lug connecting portion; Wherein, the transition portion is flexibly connected to the tab connection portion, so that the pin connection structure can be switched between a flattened state and a bent state; The pin connection structure is in a flattened state, the transition portion and the pole lug connection portion are located on the same preset plane or are substantially parallel, and both are bent together with the pole connection portion; When the pin connection structure is in a bent state, at least a portion of the transition portion and at least a portion of the tab connection portion are deformed.

15. The pin connection structure of a battery according to claim 14, characterized in that: The transition portion can deform following the deformation of the tab connecting portion.

16. The pin connection structure of a battery according to claim 15, characterized in that: The transition portion comprises a transition part and a flexible part connected in sequence, one end of the transition part away from the flexible part is connected to the pole connecting part, and one end of the flexible part away from the transition part is flexibly connected to the pole lug connecting part; The tab connection portion includes a first tab connection portion, an intermediate connection portion, and a second tab connection portion which are connected in sequence, wherein the same end of the first tab connection portion, the intermediate connection portion, and the second tab connection portion is connected to an end of the flexible portion away from the transition portion; The first tab connection portion and the second tab connection portion are both bendably connected to the middle connection portion, so that the first tab connection portion and the second tab connection portion can be bent with the middle connection portion, and the first tab connection portion and the second tab connection portion can overlap with the middle connection portion; The flexible portion can be deformed following the bending or flattening of the first tab connecting portion and the second tab connecting portion relative to the middle connecting portion.

17. The pin connection structure of a battery according to claim 16, characterized in that: The total length of the transition portion is l1, the length of the flexible portion is l2, l1 and l2 satisfy: 0.2≤l2 / l1≤0.9 and / or; When the pin connection structure is in a flattened state, the width of the tab connection portion is equal to the width of the transition portion; and / or When the pin connection structure is in a flattened state, the width of the pole connection portion is equal to the width of the transition portion.

Images