Busbar and battery pack

Abstract

The application discloses a busbar and a battery pack, comprising a first conductive busbar and a second conductive busbar arranged in a stack, the first conductive busbar is made of aluminum, and the resistivity of the second conductive busbar is less than that of the first conductive busbar; the first conductive busbar comprises a welding area, the second conductive busbar avoids the welding area, and one side of the first conductive busbar is connected with one side of the second conductive busbar. Since the resistivity of the second conductive busbar is less than that of the first conductive busbar, under the same current-carrying capacity, the second conductive busbar can be made thinner than the aluminum busbar, which helps to improve the energy density of the battery pack, and the battery pack can have a thinner and smaller size and occupy less internal space of the battery box. Since one side of the first conductive busbar and one side of the second conductive busbar are in a connected state, the current can smoothly flow from the first conductive busbar to the second conductive busbar through the joint of the side edges, and the resistance of this path is much lower than that of two conductive busbars connected by mechanical pressing and stacking, and the electrical performance is better.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a busbar and battery pack. Background Technology

[0002] Currently, batteries are generally electrically connected to the battery cells through terminals. The individual batteries in the battery pack are connected in series and parallel through the connection of the terminals to the busbar, and then connected to the power through the busbar to achieve current collection.

[0003] However, commonly used busbars are mainly made of aluminum. With the same thickness and width, aluminum busbars cannot meet the current-carrying capacity requirements of batteries, and their high current-carrying capacity can easily lead to excessive heat generation. Increasing the size or thickness of aluminum busbars would result in them occupying a larger space inside the battery casing.

[0004] Furthermore, if other conductive metals are used to make the busbar, such as copper, the busbar is generally connected to the battery terminals by welding, and since the terminals are made of aluminum, copper cannot meet the welding requirements with aluminum terminals.

[0005] Therefore, how to improve the current carrying capacity of the busbar while meeting the requirements for welding with the pole is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] In view of this, the purpose of this application is to provide a busbar that improves the current carrying capacity of the busbar while satisfying the requirements for welding with the terminal post;

[0007] Another object of this application is to provide a battery pack having the above-mentioned busbar.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] The first aspect of this application provides a bus, including a first conductive bus and a second conductive bus arranged in a stacked manner, wherein the first conductive bus is made of aluminum and the resistivity of the second conductive bus is less than that of the first conductive bus.

[0010] The first conductive bus includes a welding area, the second conductive bus avoids the welding area, one side of the first conductive bus is a first target side, the side of the second conductive bus adjacent to the first target side is a second target side, and the first target side and the second target side are connected.

[0011] The bus provided in this application includes a first conductive bus and a second conductive bus arranged in a stacked configuration. The first conductive bus is made of aluminum, and the resistivity of the second conductive bus is lower than that of the first conductive bus, meaning that the second conductive bus has a stronger current-carrying capacity than the first conductive bus. A welding area is provided on the first conductive bus, and the second conductive bus avoids this welding area, ensuring that the welding area is not obstructed by the second conductive bus. The welding area of ​​the first conductive bus can be welded to the current output terminal of a single battery cell. Since the first conductive bus is made of aluminum, welding it to the aluminum terminal of the single battery cell can achieve a strong, low-resistance weld connection. Because the resistivity of the second conductive bus is lower than that of the first conductive bus, it can be made thinner than an aluminum bus for the same current-carrying capacity, which helps to improve the energy density of the battery pack. Consequently, the bus composed of the stacked first and second conductive buses can have a thinner and smaller size than a traditional aluminum bus, reducing the space occupied inside the battery casing. With the same cross-sectional area, the lower resistance of the second conductive bus effectively reduces the heat generation and energy loss of the bus itself, improving the overall efficiency of the battery pack.

[0012] The first and second busbars are connected on one side, specifically through a rolling composite process. This process, which can be completed in a controlled factory environment, results in a connection strength, conductivity, and consistency far superior to secondary assembly on a battery module production line. This ensures the overall mechanical strength and electrical performance stability of the busbar. Because the first and second busbars are connected on one side, current can flow smoothly from the first busbar through the side joint to the second busbar. The resistance of this path is much lower than that of two busbars connected only by mechanical pressing, resulting in superior electrical performance.

[0013] A second aspect of this application provides a battery pack comprising a plurality of individual cells electrically connected via a bus, said bus being a bus as described in any of the preceding claims.

[0014] The battery pack provided in this application has all the technical effects of the aforementioned busbar, and will not be described in detail here. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the first type of bus disclosed in the embodiments of this application;

[0017] Figure 2 This is a schematic diagram of the structure of the second type of bus disclosed in the embodiments of this application at a certain angle;

[0018] Figure 3 This is a schematic diagram of the structure of the second type of bus disclosed in the embodiments of this application from another angle.

[0019] Figure 4 This is a top view of the second type of bus disclosed in the embodiments of this application;

[0020] Figure 5 for Figure 4 Sectional view along AA;

[0021] Figure 6 for Figure 4 A cross-sectional view along BB.

[0022] The meanings of the various reference numerals in the figure are as follows:

[0023] 100 - First conductive bar; 110 - Welding area; 120 - First shaped surface; 130 - First target side; 140 - First disconnection side; 150 - Bending portion;

[0024] 200 - Second conductive busbar; 210 - Clearance hole; 220 - Second face shape; 230 - Second target side; 240 - Second disconnection side. Detailed Implementation

[0025] This application discloses a busbar to improve its current carrying capacity while still satisfying the requirements for welding with the terminal post.

[0026] This application also discloses a battery pack having the above-described busbar.

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] Battery systems can be categorized from highest to lowest system level, one method being the division into battery packs, battery modules, and individual cells. This means that most lithium battery manufacturers produce battery modules based on individual cells as the smallest unit. In existing technology, individual cells are first produced, then two or more individual cells are assembled into a battery module via series-parallel connections using busbars, and finally, two or more battery modules are connected in series-parallel connections to form a battery pack.

[0029] For a battery system, the most basic functional requirement is the ability to input and output electrical energy, making the busbar particularly important. Currently, the busbar is connected to the terminals of the individual battery cells by welding.

[0030] The terminals of a single battery cell are made of aluminum, and the busbar is also made of aluminum to facilitate welding to the terminals. Because aluminum has poor current-carrying capacity, to meet battery requirements and avoid excessive heat generation due to insufficient current-carrying capacity, the busbar is usually enlarged or thickened, resulting in it occupying a significant amount of space inside the battery casing.

[0031] Based on this, embodiments of this application disclose a bus, such as Figures 1-3 As shown, the busbar includes a first conductive bus 100 and a second conductive bus 200 arranged in a stacked manner. The stacked arrangement of the first conductive bus 100 and the second conductive bus 200 means that the surfaces of the first conductive bus 100 and the second conductive bus 200 with the largest areas are bonded together. That is, the first conductive bus 100 and the second conductive bus 200 are stacked together along the thickness direction of the busbar.

[0032] The first busbar 100 is made of aluminum, and the resistivity of the second busbar 200 is lower than that of the first busbar 100. Resistivity is a physical quantity that measures the conductivity of a material. It depends only on the type of material and the ambient temperature, and is independent of the material's specific shape, size, thickness, etc. A low resistivity indicates that the material is a good conductor, and current can pass through more easily.

[0033] Among common conductors, copper and silver have lower resistivity than aluminum. Therefore, in this embodiment, copper, silver, or a copper-silver composite material can be selected as the material for the second busbar 200. Taking copper as an example, copper has a conductivity that is about 60% higher than aluminum. Under the same current carrying capacity, copper busbars can be made thinner and narrower than aluminum busbars, which helps to improve the energy density of the battery pack.

[0034] For the same cross-sectional area, copper busbars have lower resistance, effectively reducing heat generation and energy loss, and improving the overall efficiency of the battery pack. Furthermore, copper has better thermal conductivity than aluminum, allowing heat to be conducted away more quickly through the second busbar 200 during high-rate charging and discharging, helping to lower the temperature at the connection points and improve battery thermal safety and lifespan.

[0035] The first conductive bus 100 includes a welding area 110, which is the location where the first conductive bus 100 is welded to the terminal post. The first conductive bus 100 generally includes two welding areas 110, for welding to the terminal posts of two individual cells respectively.

[0036] A single battery cell typically has a positive terminal and a negative terminal. When two single cells are connected in series, the busbar needs to electrically connect the positive terminal of one cell and the negative terminal of the other. When two single cells are connected in parallel, the busbar needs to electrically connect the terminals of the same polarity of both cells. A single battery cell has a positive tab and a negative tab. The positive tab is electrically connected to the positive terminal, and the negative tab is electrically connected to the negative terminal. The terminals (positive and negative terminals) are crucial components connecting the single battery cell to an external circuit. They transfer the electrical energy generated by the cell to the external circuit and simultaneously introduce electrical energy from the external circuit into the cell for charging, acting as a bridge for current conduction.

[0037] The second conductive bus 200 needs to avoid the welding area 110. That is, the second conductive bus 200 cannot be stacked on the welding area 110 of the first conductive bus 100. In other words, there is no solid material of the second conductive bus 200 at the welding area 110. This allows the other side of the welding area 110 to be welded by the welding device after one side of the welding area 110 is attached to the pole. This avoids the second conductive bus 200 blocking the welding area 110, which would prevent the welding from being completed.

[0038] The bus disclosed in this application includes a first conductive bus 100 and a second conductive bus 200 arranged in a stacked manner. The first conductive bus 100 is made of aluminum, and the resistivity of the second conductive bus 200 is lower than that of the first conductive bus 100, meaning that the current carrying capacity of the second conductive bus 200 is stronger than that of the first conductive bus 100. A welding area 110 is provided on the first conductive bus 100, and the second conductive bus 200 avoids the welding area 110, so that the welding area 110 is not blocked by the second conductive bus 200. The welding area 110 of the first conductive bus 100 can be welded to the current output terminal of a single battery cell. Since the first conductive bus 100 is made of aluminum, welding it to the aluminum terminal of the single battery cell can achieve a strong, low-resistance weld connection. Because the resistivity of the second conductive bus 200 is lower than that of the first conductive bus 100, it can be made thinner than the aluminum bus for the same current carrying capacity. This helps to improve the energy density of the battery pack. Consequently, the busbar composed of the first conductive bus 100 and the second conductive bus 200 stacked together can be thinner and smaller than a traditional aluminum busbar, reducing its footprint within the battery housing. At the same cross-sectional area, the lower resistance of the second conductive bus 200 effectively reduces heat generation and energy loss within the busbar itself, improving the overall efficiency of the battery pack.

[0039] In this embodiment, one side of the first conductive bus 100 is the first target side 130, and the side of the second conductive bus 200 adjacent to the first target side 130 is the second target side 230. The first target side 130 and the second target side 230 are connected. The first conductive bus 100 and the second conductive bus 200 are connected on one side, specifically through a rolling composite process, where one side of the first conductive bus 100 and the second conductive bus 200 are rolled together to form a plate with the first conductive bus 100 on the left and the second conductive bus 200 on the right. However, bending can be performed at the connection point, causing the large surfaces of the first conductive bus 100 and the second conductive bus 200 to be stacked. This process can be completed in a controlled factory environment, and its connection strength, conductivity, and consistency are far superior to secondary assembly on a battery module production line, ensuring the overall mechanical strength and electrical performance stability of the busbar. Since the first conductive bus 100 and the second conductive bus 200 are connected on one side, current can flow smoothly from the first conductive bus 100 through the side joint to the second conductive bus 200. The resistance of this path is much lower than that of two conductive buses that are only mechanically pressed and stacked, resulting in better electrical performance.

[0040] In this embodiment, one side of the first conductive bus 100 and the second conductive bus 200 are connected as a single unit. Compared to a configuration where the sides are not connected and only large areas are stacked, this makes the bus disclosed in this embodiment less prone to minor misalignment during handling, positioning, and welding. This will not affect the subsequent welding quality to the battery terminals.

[0041] like Figure 1 As shown in a specific embodiment of this application, the first conductive bus 100 includes two welding areas 110, which are arranged along a first direction. The first conductive bus 100 and the second conductive bus 200 have a non-overlapping area, where the welding area 110 is formed. That is, in this embodiment, the size of the second conductive bus 200 in the first direction can be reduced, making the first conductive bus 100 larger than the second conductive bus 200 in the first direction, thereby creating a non-overlapping area. It should be noted that the first direction can be either the length direction of the first conductive bus 100 or the width direction of the second conductive bus 200, as long as a non-overlapping area can be formed on the first conductive bus 100.

[0042] Furthermore, the length of the first conductive bus 100 can be designed to be greater than the length of the second conductive bus 200, and the lengths of the first conductive bus 100 and the second conductive bus 200 are dimensions along the first direction. This results in a region in the length direction of the first conductive bus 100 that does not overlap with the second conductive bus 200, and the non-overlapping region of the first conductive bus 100 and the second conductive bus 200 forms the welding area 110.

[0043] Furthermore, along the first direction, the second conductive bus 200 is located in the middle region of the first conductive bus 100, such that the two welding areas 110 of the first conductive bus 100 have the same area, and the two welding areas 110 of the first conductive bus 100 are respectively located at both ends of the first conductive bus 100 along the first direction. This ensures that, with a fixed bus length, the two welding areas 110 have a large distance between them; it also allows the bus to have a shorter length while maintaining a suitable distance between the two welding areas 110, thereby reducing manufacturing costs.

[0044] In this embodiment, by shortening the length of the second conductive bus 200, the second conductive bus 200 will not completely cover the first conductive bus 100, thereby forming the welding area 110 in the uncovered area. This solution can reduce the amount of the second conductive bus 200 used and reduce manufacturing costs.

[0045] Furthermore, for ease of understanding, the surface where the first conductive busbar 100 and the second conductive busbar 200 are attached is defined as the target surface, the area of ​​the target surface of the first conductive busbar 100 is defined as the first area, and the projected area of ​​the second conductive busbar 200 on the target surface is defined as the second area.

[0046] In this embodiment, the ratio of the second area to the first area is 15% to 60%. For example, the ratio of the second area to the first area can be 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, etc. This embodiment does not limit the specific ratio of the second area to the first area, and those skilled in the art can select within the range of 15% to 60% based on design requirements.

[0047] This configuration avoids the problem that if the ratio is too large, the area of ​​the welding zone 110 will be too small, resulting in greater welding difficulty and lower welding strength; it also avoids the problem that if the ratio is too small, the area of ​​the second conductive bus 200 will be too small, resulting in an insignificant increase in current carrying capacity.

[0048] like Figure 2 and Figure 3As shown, in another embodiment of this application, a through-hole 210 with a wall thickness can also be formed at the position corresponding to the welding area 110 on the second conductive bus 200. That is, in this embodiment, by providing a through-hole 210 on the second conductive bus 200, the second conductive bus 200 will not completely cover the first conductive bus 100, thereby forming the welding area 110 in the area corresponding to the through-hole 210. This solution can ensure that the second conductive bus 200 has a large coverage area, ensuring the current carrying capacity of the bus. The through-hole 210 can be a round hole, a polygonal hole, etc. This embodiment does not limit the shape of the through-hole 210. Those skilled in the art can design the shape of the through-hole 210 based on the shape of the welding area 110 to be formed.

[0049] Furthermore, the first conductive bus 100 includes two welding areas 110 arranged along a first direction. Along this first direction, the two ends of the second conductive bus 200 are aligned with the two ends of the first conductive bus 100. In other words, the length of the second conductive bus 200 along the first direction is equal to the length of the first conductive bus 100 along the first direction, and their ends are aligned. The clearance holes 210 on the second conductive bus 200 can be obtained by stamping. Stamping the clearance holes 210 on the second conductive bus 200 can be performed before bending the first conductive bus 100 and the second conductive bus 200 at the connection point. That is, after stamping the clearance holes 210, bending is performed, ensuring that the first conductive bus 100 and the second conductive bus 200 remain in a stacked and fitted state.

[0050] like Figures 4-6 As shown in a specific embodiment of this application, one side of the two sides of the first conductive busbar 100 arranged along the second direction is the first target side 130, and the other side is the first disconnection side 140; one side of the two sides of the second conductive busbar 200 arranged along the second direction is the second target side 230, and the other side is the second disconnection side 240, with the first disconnection side 140 and the second disconnection side 240 aligned. The second direction is perpendicular to the first direction, and both the first and second directions are parallel to the mating surfaces of the first conductive busbar 100 and the second conductive busbar 200.

[0051] Taking the first conductive busbar 100 and the second conductive busbar 200 as examples where the outer contours are both rectangular, the first direction is the length direction of the first conductive busbar 100 and the second conductive busbar 200. That is, the two welding areas 110 are arranged along the length direction of the first conductive busbar 100. In order to ensure that the first conductive busbar 100 has a small area while satisfying the spacing between the two welding areas 110 (the spacing between the two welding areas 110 is related to the distance between the two poles to be welded), the material usage of the busbar can be reduced and the cost can be lowered.

[0052] The second direction is the width direction of the first conductive bus 100 and the second conductive bus 200. In this embodiment, one side of the first conductive bus 100 and the second conductive bus 200 is connected, while the other side is disconnected and aligned. This arrangement makes the long and wide sides of the bus substrate (the bus substrate is the structure of the first conductive bus 100 and the second conductive bus 200 before bending, that is, the first conductive bus 100 and the second conductive bus 200 have not yet been stacked and are in a coplanar state) more uniform, avoiding an excessively large aspect ratio, which would be difficult to store and easily lead to deformation before bending.

[0053] In one specific embodiment of this application, the first target side 130 of the first conductive bus 100 has a bent portion 150, so that the main body of the first conductive bus 100 and the second conductive bus 200 are stacked together. Taking the first conductive bus 100 as an aluminum bus and the second conductive bus 200 as a copper bus as an example, since aluminum is softer than copper, in this embodiment, the bending position of the first conductive bus 100 and the second conductive bus 200 is set on the first conductive bus 100, that is, the actual bent part is the aluminum first conductive bus 100. Since aluminum is softer, it is easier to bend.

[0054] like Figure 6 As shown, the bending portion 150 is further characterized by an arc-shaped bend, meaning the rounded corner (rather than a sharp angle) formed at the bend itself acts as a stress-relieving zone. This allows for better absorption and dispersion of stress generated by thermal expansion and contraction during charge-discharge cycles, improving fatigue resistance and reducing the risk of cracking at the connection between the first busbar 100 and the second busbar 200. The arc-shaped structure formed by the bend itself possesses higher bending rigidity, making the entire busbar more robust and contributing to improved overall structural stability of the battery module.

[0055] In one specific embodiment of this application, a first conductive bus 100 is provided with a first facet 120, and a second conductive bus 200 is provided with a second facet 220 stacked on top of the first facet 120. The first facet 120 and the second facet 220 can have a groove structure, and the first facet 120 and the second facet 220 are kept in a close fit. This arrangement gives the busbar composed of the first conductive busbar 100 and the second conductive busbar 200 greater resistance to deformation and torsion, further making the entire busbar more robust and helping to improve the overall structural stability of the battery module.

[0056] The first type face 120 and the second type face 220 can be located between the two welding areas 110. Specifically, the first type face 120 and the second type face 220 are located in the middle of the two welding areas 110. In other words, the two welding areas 110 can be arranged symmetrically along the first type face 120 and the second type face 220.

[0057] The thickness of the second conductive bus 200 is less than the thickness of the first conductive bus 100. The surfaces where the first conductive bus 100 and the second conductive bus 200 are bonded are called bonding surfaces, and the thicknesses of the first conductive bus 100 and the second conductive bus 200 are dimensions along a direction perpendicular to the bonding surfaces. Taking the second conductive bus 200 as a copper bus as an example, the price of copper is typically 3-4 times that of aluminum. While ensuring a sufficient conductive cross-sectional area, reducing the amount of expensive copper and increasing the amount of relatively inexpensive aluminum can significantly reduce material costs. Aluminum has a much lower density than copper; designing the first conductive bus 100 to be thicker than the second conductive bus 200, while achieving the same or similar conductive performance, further reduces the overall weight of the bus, which is crucial for applications where weight is extremely sensitive, such as electric vehicles.

[0058] Furthermore, aluminum is less hard than copper, making it softer and more ductile. Making the thicker first conductive busbar 100 the main body allows for greater flexibility throughout the busbar, making it easier to install and bend. In vibration environments, this structure better absorbs stress, reducing the risk of fracture due to metal fatigue. For the welding area 110, the thicker first conductive busbar 100 means more welding material. This provides greater tolerance for processes such as laser welding, enabling the formation of larger, stronger welds and significantly improving the mechanical strength and electrical stability of the welded area.

[0059] In this embodiment, the thickness of the first conductive bus 100 is 1mm to 2mm. For example, the thickness of the first conductive bus 100 can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc. This embodiment does not limit the thickness of the first conductive bus 100; those skilled in the art can select a thickness within the range of 1mm to 2mm based on design requirements.

[0060] The thickness of the second conductive bus 200 is 1mm to 2mm. For example, the thickness of the second conductive bus 200 can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc. This embodiment does not limit the thickness of the second conductive bus 200; those skilled in the art can select a thickness within the range of 1mm to 2mm based on design requirements.

[0061] In a specific embodiment of this application, the thickness of the welding area 110 is defined as the first thickness, and the thickness of the other areas of the first conductive bus 100 excluding the welding area 110 is defined as the second thickness. Those skilled in the art will understand that the welding area 110 of the first conductive bus 100 is welded to the electrode post using a laser welding process. To ensure welding quality, the thickness of the first conductive bus 100 has certain requirements. Typically, the thickness of the first conductive bus 100 is between 1mm and 2mm, such as 1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, etc.

[0062] In this embodiment, the second thickness can be designed to be greater than the first thickness. The thickness of the welding area 110 is designed according to the thickness required for laser welding, while the thickness of the other areas of the first conductive bus 100, excluding the welding area 110, is designed according to the current carrying capacity. Specifically, when preparing the first conductive bus 100, a first conductive bus 100 with uniform thickness can be prepared first, and then the thickness of the welding area 110 can be thinned by a machine tool.

[0063] Alternatively, the second thickness can be designed to be equal to the first thickness. In this case, the thickness of the first busbar 100 needs to be designed according to the thickness required for laser welding to meet the welding quality requirements. The current carrying capacity of the busbar is compensated by the second busbar 200, that is, by adjusting the thickness of the second busbar 200, the current carrying capacity of the busbar meets the design requirements.

[0064] This application also discloses a battery pack comprising multiple individual cells electrically connected via a busbar, wherein the busbar is the one disclosed in the previous embodiment. Because it has the aforementioned busbar, it possesses all the technical effects of the aforementioned busbar, which will not be elaborated upon further herein.

[0065] As illustrated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0066] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0068] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A busbar, characterized in that, It includes a first conductive bus (100) and a second conductive bus (200) arranged in a stacked manner. The first conductive bus (100) is made of aluminum, and the resistivity of the second conductive bus (200) is less than that of the first conductive bus (100). The first conductive bus (100) includes a welding area (110), the second conductive bus (200) avoids the welding area (110), one side of the first conductive bus (100) is a first target side (130), the side of the second conductive bus (200) adjacent to the first target side (130) is a second target side (230), and the first target side (130) and the second target side (230) are connected.

2. The busbar as described in claim 1, characterized in that, The first conductive bus (100) includes two welding areas (110) arranged along a first direction. The first conductive bus (100) and the second conductive bus (200) have a non-overlapping area, and the welding area (110) is formed in the non-overlapping area.

3. The busbar as described in claim 2, characterized in that, The length of the first conductive bus (100) is greater than the length of the second conductive bus (200), and the lengths of the first conductive bus (100) and the second conductive bus (200) are the dimensions along the first direction.

4. The busbar as described in claim 3, characterized in that, Along the first direction, the second conductive bus (200) is located in the middle region of the first conductive bus (100) such that the two welding areas (110) of the first conductive bus (100) have the same area.

5. The busbar as described in claim 3, characterized in that, The surface on which the first conductive bus (100) and the second conductive bus (200) are attached is the target surface. The area of ​​the target surface of the first conductive bus (100) is the first area, and the projected area of ​​the second conductive bus (200) on the target surface is the second area. The ratio of the second area to the first area is 15% to 60%.

6. The busbar as described in claim 1, characterized in that, The first conductive bus (100) includes two welding areas (110), and the second conductive bus (200) has a clearance hole (210) that extends through the wall thickness at the position corresponding to the welding area (110).

7. The busbar as described in claim 6, characterized in that, The first conductive bus (100) includes two welding areas (110) arranged along a first direction. Along the first direction, the two ends of the second conductive bus (200) are respectively aligned with the two ends of the first conductive bus (100).

8. The busbar as described in claim 6, characterized in that, The clearance hole (210) is a round hole or a polygonal hole.

9. The busbar as described in claim 1, characterized in that, The first conductive bus (100) includes two welding areas (110) arranged along a first direction; One side of the first conductive bus (100) arranged along the second direction is the first target side (130), and the other side is the first disconnection side (140); one side of the second conductive bus (200) arranged along the second direction is the second target side (230), and the other side is the second disconnection side (240), and the first disconnection side (140) is aligned with the second disconnection side (240); The second direction is perpendicular to the first direction, and both the first direction and the second direction are parallel to the mating surfaces of the first conductive bus (100) and the second conductive bus (200).

10. The busbar as described in claim 1, characterized in that, The first target side (130) of the first conductive bus (100) has a bend (150) so that the main body of the first conductive bus (100) is stacked with the second conductive bus (200).

11. The busbar as described in claim 10, characterized in that, The bending portion (150) is an arc-shaped bending portion.

12. The busbar as described in claim 1, characterized in that, The first conductive bus (100) is provided with a first face part (120), and the second conductive bus (200) is provided with a second face part (220) stacked with the first face part (120).

13. The busbar as described in claim 12, characterized in that, The first conductive bus (100) includes two welding areas (110), with the first face portion (120) and the second face portion (220) located between the two welding areas (110).

14. The busbar as described in claim 13, characterized in that, The first face (120) and the second face (220) are located between the two welding areas (110).

15. The busbar as described in any one of claims 1-14, characterized in that, The thickness of the second conductive bus (200) is less than the thickness of the first conductive bus (100); The surfaces on which the first conductive bus (100) and the second conductive bus (200) are attached are called the bonding surfaces, and the thicknesses of the first conductive bus (100) and the second conductive bus (200) are dimensions along a direction perpendicular to the bonding surfaces.

16. The bus as described in any one of claims 1-14, characterized in that, The thickness of the first conductive bus (100) is 1mm~2mm; And / or, The thickness of the second conductive bus (200) is 1mm~2mm.

17. The busbar according to any one of claims 1-14, characterized in that, The thickness of the welding area (110) is a first thickness, and the thickness of the other areas of the first conductive bus (100) excluding the welding area (110) is a second thickness, the second thickness being greater than or equal to the first thickness.

18. The busbar according to any one of claims 1-14, characterized in that, The second conductive bus (200) is made of copper, silver or copper-silver composite material.

19. A battery pack, characterized in that, It includes multiple individual cells electrically connected by a bus, wherein the bus is a bus as described in any one of claims 1-18.

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