Battery cell, battery, and electrical device

Abstract

The present application relates to a battery cell, a battery, and an electrical device. The battery cell includes an electrode assembly, which includes a first tab and a second tab, and the first tab and the second tab are respectively located at two ends of the electrode assembly in a first direction; a first electrode terminal and a second electrode terminal, and the first electrode terminal and the second electrode terminal are respectively located on two sides of the electrode assembly in the first direction; a first adapter for connecting the first tab to the first electrode terminal; and a second adapter for connecting the second tab to the second electrode terminal; wherein, both the first adapter and the second adapter include at least two non-bending portions and a bending portion connecting adjacent non-bending portions, and the number of non-bending portions of the second adapter is greater than the number of non-bending portions of the first adapter. The battery cell provided in the present application aims to solve the problem that the overall volume of the battery increases due to the improvement of the energy density of the battery.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery cell, a battery, and an electrical device. Background Art

[0002] Rechargeable batteries have the advantages of small volume, low self-discharge, no memory effect, high safety, and environmental friendliness, and are promising high-efficiency secondary batteries and chemical energy storage power sources, and have been widely used in the fields of electric vehicles, energy storage, and communication.

[0003] With the increasing requirement for the cruising range of electric vehicles and the like, the requirement for the cruising performance of rechargeable batteries is getting higher and higher. The key factor determining the cruising performance of a battery is the energy density of the battery. The improvement of the energy density usually requires an increase in the volume of the electrode assembly of the battery. The increase in the volume of the electrode assembly will cause an increase in the overall volume of the rechargeable battery. Generally, the installation space provided by an electric vehicle for the battery is limited space, so it is not conducive to the assembly of multiple groups of batteries in the limited space. Summary of the Invention

[0004] The present application provides a battery cell, a battery, and an electrical device, aiming to improve the energy density of the battery.

[0005] On the one hand, the present application provides a battery cell, which includes: an electrode assembly including a first tab and a second tab, the first tab and the second tab are respectively located at two ends of the electrode assembly in a first direction; a first electrode terminal and a second electrode terminal, the first electrode terminal and the second electrode terminal are respectively located on two sides of the electrode assembly in the first direction; a first adapter for connecting the first tab to the first electrode terminal; and a second adapter for connecting the second tab to the second electrode terminal; wherein, both the first adapter and the second adapter include at least two non-bending portions and a bending portion connecting adjacent two non-bending portions, and the number of non-bending portions of the second adapter is greater than the number of non-bending portions of the first adapter. The battery cell according to the embodiment of the present application includes a first adapter and a second adapter. Both the first adapter and the second adapter include at least two non-bending portions and a bending portion connected between each adjacent two non-bending portions. Both the first adapter and the second adapter are of a stacked structure, occupying a small space and improving the space utilization rate of the battery cell. Moreover, compared with the number of non-bending portions of the second adapter, the number of non-bending portions of the first adapter is reduced, the number of bending times of the first adapter is relatively reduced, and the occupied space of the first adapter is reduced, which can further improve the space utilization rate of the battery cell, thereby improving the energy density of the battery cell and further enhancing the cruising performance of the battery.

[0006] According to an embodiment of the present application, at least two non-bending portions of the first adapter include a first non-bending portion and a second non-bending portion, the first non-bending portion is connected to the first electrode terminal, and the second non-bending portion is connected to the first pole ear; at least two non-bending portions of the second adapter include a third non-bending portion, a fourth non-bending portion, and a fifth non-bending portion, the third non-bending portion is connected to the second electrode terminal, the fourth non-bending portion is connected to the second pole ear, and the fifth non-bending portion is arranged between the third non-bending portion and the fourth non-bending portion. The stacked first adapter does not need to be welded as a whole, which greatly reduces the difficulty of welding the first adapter, the first electrode terminal, and the first pole ear.

[0007] According to an embodiment of the present application, the resistivity of the second adapter is smaller than that of the first adapter, thereby reducing the resistance difference between the first adapter and the second adapter, making the heat generated by the first adapter and the second adapter close to each other, and improving the consistency of the battery cells.

[0008] According to an embodiment of the present application, the material of the first transition component is aluminum, and the material of the second transition component is copper.

[0009] According to an embodiment of the present application, the length of the second adapter is greater than the length of the first adapter, so that the thermal design of the first adapter and the second adapter is more balanced.

[0010] According to an embodiment of the present application, the minimum thickness of the bent portion is less than the minimum thickness of the non-bent portion. The first adapter and the second adapter are easier to bend, which reduces the difficulty of inserting into the shell; and the stacked first adapter and the second adapter formed by bending have a smaller gap at the bend, which can improve the space utilization of the battery cell.

[0011] According to an embodiment of the present application, the bending portion includes a transition section, the transition section is connected to the non-bending portion, and the thickness of the transition section gradually decreases in a direction away from the connected non-bending portion. The stress at the connection between the bending portion and the connected non-bending portion can be reduced, and the possibility of the first transition member and the second transition member being broken can be reduced.

[0012] According to an embodiment of the present application, the first electrode terminal penetrates and connects the non-bending portion of the first adapter, so that the welding position of the first electrode terminal and the first adapter can be accurately positioned, thereby improving the welding yield.

[0013] According to one embodiment of the present application, the first electrode terminal includes a first terminal body and a first platform portion and a first protrusion portion respectively connected to the first terminal body, the first protrusion portion penetrates and connects to the non-bending portion of the first adapter, and the first platform portion abuts against a side of the non-bending portion of the first adapter away from the first pole ear. The first platform portion is used to limit the displacement of the first protrusion portion in the first direction to prevent the first electrode terminal from slipping out of the first adapter before welding.

[0014] In another aspect, the present application provides a battery, which includes a battery cell as in the above embodiment. By increasing the energy density of the battery cell, the endurance performance of the battery is improved accordingly.

[0015] In yet another aspect, the present application provides an electrical device, which includes a battery cell as in the above embodiment. The battery cell is used to provide electrical energy. By increasing the energy density of the battery cell, the endurance performance of the electrical device is improved accordingly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The features, advantages, and technical effects of the exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0017] Figure 1a is a schematic structural diagram of a vehicle disclosed in an embodiment of the present application;

[0018] Figure 1b is a schematic structural diagram of a battery disclosed in an embodiment of the present application;

[0019] Figure 2 is a schematic structural diagram of a battery module disclosed in an embodiment of the present application;

[0020] Figure 3 is an exploded structural diagram of a battery module disclosed in an embodiment of the present application;

[0021] Figure 4 is an exploded structural diagram of a battery cell disclosed in an embodiment of the present application;

[0022] Figure 5 is Figure 4 a top view structural diagram of

[0023] Figure 6 is Figure 5 a sectional structural diagram taken along the A-A direction;

[0024] Figure 7 is an exploded structural diagram of a second end cap assembly;

[0025] Figure 8 is a sectional view of a second end cap assembly;

[0026] Figure 9 is a schematic structural diagram of a second adapter in a non-bent state;

[0027] Figure 10 is a sectional structural diagram of a second adapter taken along the B-B direction;

[0028] Figure 11 is Figure 10 a partial enlarged structural diagram of I of

[0029] Figure 12 It is a schematic exploded view of the first end cap assembly;

[0030] Figure 13 It is a schematic view of the non-bent state structure of the first adapter;

[0031] Figure 14 It is a schematic cross-sectional view of the first adapter along the C-C direction;

[0032] Figure 15 It is a manufacturing process diagram of the battery cell.

[0033] In the drawings, the drawings are not necessarily drawn to actual scale.

[0034] Among them, the reference numerals in the drawings:

[0035] 1, vehicle; 1a, motor; 1b, controller;

[0036] 10, battery; 11, first part; 12, second part;

[0037] 20, battery module;

[0038] 30, housing; 31, cylinder; 32, first cover; 33, second cover;

[0039] 40, battery cell;

[0040] 50, housing;

[0041] 60, electrode assembly; 61, first tab; 62, second tab;

[0042] 70, end cap; 71, riveting block; 72, first insulating part; 73, top cover piece; 74, second insulating part; 75, seal;

[0043] 801, first electrode terminal; 81, first terminal body; 82, first platform part; 83, first protrusion part;

[0044] 802, second electrode terminal; 84, second terminal body; 85, second platform part; 86, second protrusion part; 90, first adapter; 91, first non-bent part; 92, second non-bent part; 93, first bent part;

[0045] 100, second adapter; 110, third non-bent part; 111, first through hole; 120, fifth non-bent part; 121, second through hole; 140, fourth non-bent part;

[0046] 130, bent part; 131, transition section; 132, middle section. Detailed implementation manners

[0047] The embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the examples and the drawings are used to exemplarily illustrate the principle of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0048] In the description of the present application, it should be noted that unless otherwise specified, the meaning of "a plurality" is more than two; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", etc. is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0049] In the description of the present application, it should also be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0050] The applicant noticed that the common way to increase the energy density of existing battery cells is usually to increase the volume of the electrode assembly of the battery. However, the increase in the volume of the electrode assembly will lead to an increase in the volume of other components associated with the electrode assembly, such as the housing that houses the electrode assembly. This will result in an increase in the overall occupied space of the battery cell, which is not conducive to the assembly of multiple battery cells in a limited space, and will also lead to a significant increase in the input cost, which is not conducive to practical applications. To avoid the adverse problems caused by the increase in the overall volume of the battery cell, the applicant started from the space utilization rate inside the battery cell, improved the space utilization rate, and thus increased the battery energy density. The applicant designed the structural form of the connecting piece and found that the connecting piece after bending and stacking occupies less space, and the current-carrying capacity of the stacked connecting piece is large, which can greatly improve the space utilization rate of the battery and increase the energy density. The positive and negative connecting pieces generally adopt the structure with the same number of stacked layers. The applicant found that even if the number of stacked layers of one end of the connecting piece is reduced, the production requirements can still be met; therefore, using the positive and negative connecting pieces with the same number of stacked layers results in a waste of the internal space of the battery cell and reduces the space utilization rate.

[0051] Based on the above problems discovered by the applicant, the applicant improved the structure of the battery cell, and the embodiments of the present application will be further described below.

[0052] To better understand the present application, the following will describe the embodiments of the present application in conjunction with Figures 1a to 15 the embodiments of the present application.

[0053] The embodiments of the present application provide an electrical device that uses the battery 10 as a power source. The electrical device may be, but is not limited to, a vehicle, a ship, an aircraft, etc. Refer to Figure 1a As shown, an embodiment of the present application provides a vehicle 1. The vehicle 1 may be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range-extended vehicle, etc. In an embodiment of the present application, the vehicle 1 may include a motor 1a, a controller 1b, and a battery 10. The controller 1b is used to control the battery 10 to supply power to the motor 1a. The motor 1a is connected to the wheels through a transmission mechanism, thereby driving the vehicle 1 to travel. The battery 10 may serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1. In one example, the battery 10 may be disposed at the bottom, the front end, or the rear end of the vehicle 1. The battery 10 may be used to supply power to the vehicle 1. In one example, the battery 10 may serve as the operating power source of the vehicle 1 and be used for the circuit system of the vehicle 1. Exemplarily, the battery 10 may be used for the power consumption requirements during the start-up, navigation, and operation of the vehicle 1.

[0054] Refer to Figure 1b As shown, the battery 10 includes a box body. The type of the box body is not limited. The box body may be a frame-shaped box body, a disk-shaped box body, a box-shaped box body, etc. Exemplarily, the box body includes a first part 11 and a second part 12 that covers the first part 11. After the second part 12 and the first part 11 are covered, a receiving portion is formed.

[0055] Figure 2 Schematically shows a battery module 20 of an embodiment, and the battery module 20 is disposed in the box body. The battery module 20 includes a plurality of battery cells 40.

[0056] In some embodiments, in order to meet different power usage requirements, the battery 10 may include a plurality of battery cells 40. Among them, the plurality of battery cells 40 may be connected in series, in parallel, or in a series-parallel combination. The series-parallel combination refers to the combination of series and parallel. That is to say, the plurality of battery cells 40 may be directly disposed in the receiving portion of the box body to form the battery 10.

[0057] Refer to Figure 2 and Figure 3As shown, the battery module 20 includes a housing 30 and battery cells 40 disposed within the housing 30. In one example, the housing 30 includes a cylindrical body 31, a first cover 32, and a second cover 33. The first cover 32 and the second cover 33 are respectively disposed at both ends of the cylindrical body 31. The first cover 32 and the second cover 33 are respectively detachably connected to the cylindrical body 31. For example, the first cover 32 and the second cover 33 can be respectively snap-fitted or screwed to the cylindrical body 31. After the cylindrical body 31, the first cover 32, and the second cover 33 are assembled, an accommodation space is formed. The battery cells 40 are disposed within the accommodation space of the housing 30.

[0058] It should be understood that the structure of the housing 30 is not limited to the above embodiments. For example, the housing 30 is formed by snap-fitting two open cover-like parts, as long as it can achieve the assembly of multiple battery cells 40.

[0059] See Figure 4 As shown, the battery cell 40 of the embodiment of the present application includes a housing 50 and an electrode assembly 60 disposed within the housing 50. The housing 50 of the embodiment of the present application is a cylindrical structure or other structures. The housing 50 has an internal space for accommodating the electrode assembly 60 and electrolyte and an opening communicating with the internal space. The housing 50 can be made of materials such as aluminum, aluminum alloy, or plastic. The electrode assembly 60 of the embodiment of the present application can be formed by stacking or winding a first electrode tab, a second electrode tab, and a separator together, where the separator is an insulator between the first electrode tab and the second electrode tab. In this embodiment, for example, the first electrode tab is used as the positive electrode tab and the second electrode tab is used as the negative electrode tab for illustration. Both the positive electrode tab and the negative electrode tab include a coated area and an uncoated area. The positive electrode active material is coated on the coated area of the positive electrode tab, while the negative electrode active material is coated on the coated area of the negative electrode tab. On the coated area, the active material is coated on a current collector formed by a metal thin plate, and no active material is coated on the uncoated area.

[0060] See Figure 5 and Figure 6 As shown, the electrode assembly 60 includes a main body portion, a first electrode tab 61, and a second electrode tab 62. The main body portion has two opposite ends. The first electrode tab 61 and the second electrode tab 62 are respectively located at both ends of the electrode assembly 60 in a first direction. It can be understood that the first direction can be the length direction of the electrode assembly 60. In the embodiment of the present application, for example, the first electrode tab 61 is used as the positive electrode tab and the second electrode tab 62 is used as the negative electrode tab for illustration. The uncoated areas of the positive electrode tabs are stacked to form the positive electrode tab, while the uncoated areas of the negative electrode tabs are stacked to form the negative electrode tab. The positive electrode tab and the negative electrode tab respectively extend from one end of the main body portion.

[0061] See Figure 4 and Figure 6As shown, the battery cell 40 of the embodiment of the present application also includes an end cap assembly, and the end cap assembly includes an end cap 70, an electrode terminal and an adapter. The end cap 70 is sealed and connected to the shell 50. The electrode terminal is arranged on the end cap 70. The electrode terminal is electrically connected to the electrode assembly 60 through the adapter. The adapter has a drainage effect on the electrode terminal and the electrode assembly 60, which can ensure normal current conduction between the electrode terminal and the electrode assembly 60. The number of end caps 70, the number of electrode terminals and the number of adapters are all two. An end cap assembly is correspondingly arranged on each of the two sides of the first direction of the electrode assembly 60 (i.e., the two sides opposite to each other in the length direction of the electrode assembly 60).

[0062] See also Figure 6 and Figure 7 as well as Figure 12 ,in, Figure 6 The adapter in the battery cell shown is a structure in a bent state; Figure 7 The adapter in the second end cap assembly shown is a structure in a non-bent state; Figure 12 The adapter in the first end cap assembly shown is a structure in a non-bent state; illustratively, the first end cap assembly and the second end cap assembly are respectively arranged on both sides of the first direction of the electrode assembly 60. The first end cap assembly includes an end cap 70, a first electrode terminal 801 and a first adapter 90, and the first electrode terminal 801 and the first electrode tab 61 can be connected through the first adapter 90. The second end cap assembly can include an end cap 70, a second electrode terminal 802 and a second adapter 100, and the second electrode terminal 802 and the second electrode tab 62 can be connected through the second adapter 100.

[0063] See also Figures 6 to 12 , the first adapter 90 and the second adapter 100 may each include at least two non-bending portions and a bending portion 130 connected between each two adjacent non-bending portions, and the number of non-bending portions of the second adapter 100 is greater than the number of non-bending portions of the first adapter 90. After being inserted into the shell, the first adapter 90 and the second adapter 100 are both stacked structures, which occupy a small space and can improve the space utilization rate of the battery cell 40 and further improve the energy density of the battery cell 40; and compared with the number of non-bending portions of the second adapter 100, the number of non-bending portions of the first adapter 90 is reduced, the number of bending times of the first adapter 90 is relatively reduced, and the space occupied by the first adapter 90 is reduced, which can further improve the space utilization rate of the battery cell, thereby improving the energy density of the battery cell 40, and further improving the battery life performance.

[0064] See also Figures 6 to 11, exemplarily, the at least two non-bending portions of the second adapter 100 include a third non-bending portion 110, a fourth non-bending portion 140 and a fifth non-bending portion 120, the third non-bending portion 110 is connected to the second electrode terminal 802, the fourth non-bending portion 140 is connected to the second electrode ear 62, and the fifth non-bending portion 120 is arranged between the third non-bending portion 110 and the fourth non-bending portion 140. The second adapter 100 and the second pole lug 62 and the second electrode terminal 802 are usually connected by welding, such as laser welding or ultrasonic welding. When welding the second adapter 100 and the second pole lug 62, it is only necessary to weld the fourth non-bending portion 140 and the second pole lug 62; when welding the second adapter 100 and the second electrode terminal 802, it is only necessary to weld the third non-bending portion 110 and the second electrode terminal 802; the stacked second adapter 100 does not require the overall welding of the second adapter 100, which greatly reduces the difficulty of welding the second adapter 100, the second electrode terminal 802 and the second pole lug 62.

[0065] In some embodiments, the second electrode terminal 802 may also penetrate and connect the non-bending portion of the second adapter 100. As an example, the second electrode terminal 802 includes a second terminal body 84 and a second protrusion 86. The non-bending portion of the second adapter 100 is provided with a third through hole, and the second protrusion 86 is arranged in the third through hole to achieve the connection between the second protrusion 86 and the second adapter 100. Through the cooperation of the second protrusion 86 and the third through hole, the total height occupied by the second electrode terminal 802 and the second adapter 100 can be reduced, and the energy density of the battery cell 40 can be further improved. At the same time, the welding position can be accurately positioned, and the welding process is simple and easy to assemble. Exemplarily, the second protrusion 86 and the second adapter 100 can be welded by seam welding. Of course, the second electrode terminal 802 can also be directly welded to one side of the non-bending portion of the second adapter 100, without the need for the second electrode terminal 802 and the second adapter 100 to be welded as a whole, which can reduce the difficulty of welding. The specific welding method between the second electrode terminal 802 and the second adapter 100 is not limited here.

[0066] In some embodiments, the second electrode terminal 802 may also be provided with a second platform portion 85 , which abuts against a side of the non-bending portion of the second adapter 100 away from the second electrode tab 62 , and the second platform portion 85 abuts against the third non-bending portion 110 .

[0067] In some embodiments, to increase the infiltration of the electrolyte, a through hole may be provided on the non-bending portion connected to the second electrode tab 62. As an example, the second through hole 121 may be provided on the fourth non-bending portion of the second adapter 100.

[0068] See also Figure 6 and Figures 12 to 14, illustratively, the at least two non-bending portions of the first adapter 90 may include a first non-bending portion 91 and a second non-bending portion 92, the first non-bending portion 91 is connected to the first electrode terminal 801, and the second non-bending portion 92 is connected to the first pole tab 61. The first adapter 90 and the first pole tab 61 and the first electrode terminal 801 are usually connected by welding, such as laser welding, ultrasonic welding, etc. When welding the first adapter 90 and the first pole tab 61, only the second non-bending portion 92 and the first pole tab 61 need to be welded; when welding the first adapter 90 and the first electrode terminal 801, only the first non-bending portion 91 and the first electrode terminal 801 need to be welded; the stacked first adapter 90 does not need to be welded as a whole of the first adapter 90, which greatly reduces the difficulty of welding the first adapter 90 and the first electrode terminal 801 and the first pole tab 61.

[0069] In some embodiments, the first electrode terminal 801 can penetrate and connect the non-bending portion of the first adapter 90; as an example, the first electrode terminal 801 includes a first terminal body 81 and a first protrusion 83, the first non-bending portion 91 of the first adapter 90 is provided with a first through hole 111, and the first protrusion 83 is arranged in the first through hole 111 to achieve the connection between the first protrusion 83 and the first adapter 90. Through the cooperation of the first protrusion 83 and the first through hole 111, the total height occupied by the first electrode terminal 801 and the first adapter 90 can be reduced, and the energy density of the battery cell 40 can be further improved. At the same time, the welding position can be accurately positioned, and the welding process is simple and easy to assemble. Exemplarily, the first protrusion 83 and the first adapter 90 can be welded by butt welding. Of course, the first electrode terminal 801 can also be directly welded to one side of the non-bending portion of the first adapter 90, without the need for the first electrode terminal 801 and the first adapter 90 to be welded as a whole, which can reduce the difficulty of welding. The specific welding method between the first electrode terminal 801 and the first adapter 90 is not limited here.

[0070] In some embodiments, the first electrode terminal 801 may also be provided with a first platform portion 82, and the first platform portion 82 abuts against the side of the first non-bending portion 91 of the first adapter 90 away from the first pole ear 61. The first platform portion 82 abuts against the first non-bending portion 91, and can limit the first protrusion 83, thereby limiting the displacement of the first protrusion 83 in the first direction, and preventing the first electrode terminal 801 from slipping out of the first adapter 90 before welding.

[0071] In some embodiments, to increase the infiltration of the electrolyte, a through hole may be provided on the non-bending portion connected to the first electrode tab 61. As an example, a second through hole 121 may be provided on the second non-bending portion 92 of the first adapter 90.

[0072] In some embodiments, seeFigures 7 to 12 The minimum thickness of the bent portion 130 of the adapter can be less than the minimum thickness of the non-bent portion. If the bent portion 130 and the non-bent portion have the same thickness, when the adapter is bent, the bent portion 130 will protrude towards the direction of the connected non-bent portion, and the height of the bent portion 130 after bending is higher than the height of the connected non-bent portion, resulting in a higher height of the stacked adapter and a large occupied space. However, the minimum thickness of the bent portion 130 in this embodiment is smaller, so when the adapter is bent, the bending pressure is smaller and the bending is easier; and bending the bent portion 130 into an arc shape can reduce the possibility of the bent portion 130 protruding towards the direction of the connected non-bent portion. The gap at the bent portion of the formed stacked adapter is smaller, thereby reducing the occupied space of the bent portion 130, improving the space utilization rate of the battery cell, and further enhancing the energy density of the battery cell. It can reduce the space occupied by the stacked adapter, improve the space utilization rate of the battery cell, and further enhance the energy density of the battery cell.

[0073] As an example, the minimum thickness of the bent portion 130 of the first adapter 90 can be less than the thickness of the non-bent portion. It can be that the minimum thickness of the bent portion 130 of the first adapter 90 is less than the minimum thickness of any one of the first non-bent portion 91 and the second non-bent portion 92, or the minimum thickness of the bent portion 130 of the first adapter 90 is less than the minimum thickness of one of the first non-bent portion 91 and the second non-bent portion 92.

[0074] As an example, the minimum thickness of the bent portion 130 of the second adapter 100 can be less than the minimum thickness of the non-bent portion. The minimum thickness of the bent portion 130 of the second adapter 100 can be less than the minimum thickness of any one of the third non-bent portion 110, the fourth non-bent portion 140, and the fifth non-bent portion 120.

[0075] In some embodiments, the bent portion 130 may include a transition section 131 and an intermediate section 132. The two ends of the intermediate section 132 are respectively connected to a transition section 131. The transition section 131 is connected to the non-bent portion, and the thickness of the transition section 131 gradually decreases in the direction away from the connected non-bent portion; the bent portion 130 and the connected non-bent portion are smoothly transitionally connected. The stress at the connection between the bent portion 130 and the connected non-bent portion is reduced, and the possibility of the first adapter 90 and the second adapter 100 breaking is lowered. It can be understood that the bent portion 130 and the non-bent portion can be an integral structure; of course, the bent portion 130 and the non-bent portion can also be a split structure, connected by welding, etc., and specific limitations are not imposed here.

[0076] Please refer to Figure 15 , Figure 15 a shows a schematic diagram of the laser welding of the second adapter 100 and the second tab 62. Figure 15b shows a schematic diagram of the second adapter 100 after secondary bending. Figure 15 c shows a schematic diagram of laser welding between the first adapter 90 and the first tab 61. Figure 15 d shows a schematic diagram of the first adapter 90 and the second adapter 100 after being bent and inserted into the housing. In the embodiments of the present application, the process of inserting the first adapter 90 and the second adapter 100 into the housing may include the following steps:

[0077] S100, laser-weld the second adapter 100 to the second tab 62 of the electrode assembly 60;

[0078] S200, perform primary bending on the second adapter 100;

[0079] S300, perform secondary bending on the second adapter 100;

[0080] S400, insert the second adapter 100 and the electrode assembly 60 into the housing, so that the end of the main body portion of the first tab 61 formed by extension is higher than the opening of the housing 50;

[0081] S500, laser-weld the first adapter 90 to the first tab 61 of the electrode assembly 60;

[0082] S600, perform primary bending on the first adapter 90;

[0083] S700, bend and insert the first adapter 90 and the second adapter 100 into the housing.

[0084] In the second adapter 100 of this embodiment and the electrode assembly 60, there is no need to be flipped during the battery assembly process, and the assembly is easy to implement; in the first adapter 90 and the electrode assembly 60, only one bending is required during the battery assembly process, which can accurately position with the electrode assembly 60 and facilitate insertion into the housing.

[0085] In some embodiments, the resistivity of the second adapter 100 is less than that of the first adapter 90, so as to reduce the resistance difference between the two adapters, make the heat generated by the first adapter 90 and the second adapter 100 close, and improve the consistency of the battery cell 40. Exemplarily, taking the first adapter 90 as the positive adapter and the second adapter 100 as the negative adapter as an example for illustration. For example, the material of the first adapter 90 is aluminum, and the material of the second adapter 100 is copper. The resistivity of the positive adapter is greater than that of the negative adapter. For positive and negative adapters of the same specification, compared with the positive adapter, the negative adapter will generate more heat, and there will be problems such as uneven temperature distribution and excessive local temperature rise between the positive and negative adapters.

[0086] In some embodiments, to make the thermal design of the positive electrode adapter and the negative electrode adapter more balanced, the length of the second adapter 100 is greater than the length of the first adapter 90. Exemplarily, taking the first adapter 90 as the positive electrode adapter and the second adapter 100 as the negative electrode adapter as an example, the length of the negative electrode adapter can be set to be greater than the length of the positive electrode adapter.

[0087] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any manner. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, it includes: An electrode assembly (60), including a first tab (61) and a second tab (62), the first tab (61) and the second tab (62) are respectively located at two ends of the electrode assembly (60) in a first direction; A first electrode terminal (801) and a second electrode terminal (802), the first electrode terminal (801) and the second electrode terminal (802) are respectively located on two sides of the electrode assembly (60) in the first direction; A first adapter (90) for connecting the first tab (61) and the first electrode terminal (801); and A second adapter (100) for connecting the second tab (62) and the second electrode terminal (802); wherein, both the first adapter (90) and the second adapter (100) include at least two non-bent portions and a bent portion (130) connecting adjacent two of the non-bent portions, all the non-bent portions of the first adapter (90) are stacked along the first direction, and all the non-bent portions of the second adapter (100) are stacked along the first direction; the number of the non-bent portions of the second adapter (100) is greater than the number of the non-bent portions of the first adapter (90), the length of the second adapter (100) is greater than the length of the first adapter (90), the resistivity of the second adapter (100) is less than the resistivity of the first adapter (90).

2. The battery cell according to claim 1, characterized in that, the at least two non-bent portions of the first adapter (90) include a first non-bent portion (91) and a second non-bent portion (92), the first non-bent portion (91) is connected to the first electrode terminal (801), and the second non-bent portion (92) is connected to the first tab (61); the at least two non-bent portions of the second adapter (100) include a third non-bent portion (110), a fourth non-bent portion (140) and a fifth non-bent portion (120), the third non-bent portion (110) is connected to the second electrode terminal (802), the fourth non-bent portion (140) is connected to the second tab (62), and the fifth non-bent portion (120) is arranged between the third non-bent portion (110) and the fourth non-bent portion (140).

3. The battery cell according to claim 1, characterized in that, the material of the first adapter (90) is aluminum, and the material of the second adapter (100) is copper.

4. The battery cell according to claim 1, characterized in that, the minimum thickness of the bent portion (130) is less than the minimum thickness of the non-bent portion.

5. The battery cell according to claim 1, characterized in that, the bent portion (130) includes a transition section (131), the transition section (131) is connected to the non-bent portion, and the thickness of the transition section (131) gradually decreases in a direction away from the connected non-bent portion.

6. The battery cell according to claim 1, wherein, the first electrode terminal (801) penetrates and connects to the non-bent portion of the first adapter (90).

7. The battery cell according to claim 6, wherein, the first electrode terminal (801) includes a first terminal body (81), a first platform portion (82) and a first protrusion portion (83), the first terminal body (81) is respectively connected to the first platform portion (82) and the first protrusion portion (83), the first protrusion portion (83) penetrates and connects to the non-bent portion of the first adapter (90), and the first platform portion (82) abuts against the side of the non-bent portion of the first adapter (90) away from the first tab (61).

8. A battery, wherein, it includes the battery cell according to any one of claims 1 to 7.

9. An electrical device, wherein, it includes the battery according to claim 8, and the battery is used to provide electrical energy.

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