Battery cell and electrical equipment

Abstract

The present application relates to the technical field of batteries, and discloses a battery cell and an electrical device. The battery cell includes a housing, an electrode terminal, an electrode assembly, a tab, and a metal sheet. The housing has a first wall, the electrode terminal is disposed on the first wall, the electrode assembly is disposed inside the housing, the tab is disposed inside the housing, the tab has a first end and a second end, the first end is connected to the electrode assembly, and the second end is disposed between the metal sheet and the electrode terminal. The metal sheet, the second end, and the electrode terminal are welded and fixed. Wherein, the metal sheet includes a body portion and a protruding portion, the protruding portion protrudes towards the electrode terminal relative to the body portion, the protruding portion includes a bottom wall and a peripheral wall, the peripheral wall surrounds the outer peripheral edge of the bottom wall and connects the bottom wall and the body portion, a welding mark is disposed on the bottom wall, the minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D, the hardness of the metal sheet is A, and the thickness of the tab is D, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB. It solves the technical problem of tab tearing in battery welding.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular, to a battery cell and an electrical device. Background Art

[0002] With the development and maturity of battery technology, the scope of application of battery technology is becoming more and more extensive, such as electrical devices like electric vehicles and small electric drones. For electrical devices, battery technology is an important factor related to their development. However, in the related art, during the welding process of the tab and the terminal, tab bulges are likely to occur, causing tab tearing and reducing the reliability of the battery during the manufacturing process. Summary of the Invention

[0003] This application provides a battery cell and an electrical device, which solve the technical problem of tab tearing during battery welding and achieve the technical effect of improving the reliability of the battery during the manufacturing process.

[0004] To achieve the above object, the main technical solutions adopted in this application include:

[0005] In a first aspect, an embodiment of this application provides a battery cell. The battery cell includes a housing, an electrode terminal, an electrode assembly, a tab, and a metal sheet. The housing has a first wall, the electrode terminal is disposed on the first wall, the electrode assembly is disposed inside the housing, the tab is disposed inside the housing, the tab has a first end and a second end, the first end is connected to the electrode assembly, the second end is disposed between the metal sheet and the electrode terminal, and the metal sheet, the second end, and the electrode terminal are welded and fixed. Among them, the metal sheet includes a body portion and a protruding portion. The protruding portion protrudes toward the electrode terminal relative to the body portion. The protruding portion includes a bottom wall and a peripheral wall. The peripheral wall surrounds the outer peripheral edge of the bottom wall and connects the bottom wall and the body portion. A welding mark is provided on the bottom wall. The minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D, the hardness of the metal sheet is A, and the thickness of the tab is W, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB.

[0006] For the battery cell proposed in the embodiment of this application, the minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D, the hardness of the metal sheet is A, and the thickness of the tab is W, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB, which can effectively reduce the probability of tab tearing under the condition of meeting the performance of the battery cell (good current flow between the tab and the electrode terminal), improve the stability of the connection between the tab and the electrode terminal, and improve the quality of battery cell manufacturing.

[0007] In a second aspect, an embodiment of this application further provides an electrical device, including any one of the battery cells described in the embodiments of this application.

[0008] For the electrical device proposed in the embodiment of the present application, the minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D, the hardness of the metal sheet is A, and the thickness of the tab is W, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB, which can effectively reduce the probability of the tab being torn under the condition of meeting the performance of the battery cell (good current flow between the tab and the electrode terminal), improve the stability of the connection between the tab and the electrode terminal, and improve the quality of manufacturing the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0010] Figure 1 It is an exploded structural view of a battery cell provided by an embodiment of the present application;

[0011] Figure 2 It shows the positional relationship among the metal sheet, the electrode terminal, and the tab in an embodiment of the present application;

[0012] Figure 3 It shows the structure of the welding mark and the metal sheet in an embodiment of the present application;

[0013] Figure 4 It shows the positional relationship among the metal sheet, the electrode terminal, and the tab in an embodiment of the present application.

[0014]

DESCRIPTION OF THE REFERENCE NUMERALS

[0015] Battery cell 100A; housing 110; first wall 111; electrode terminal 120; electrode assembly 130; tab 140; first end 141; second end 142; metal sheet 150; body portion 151; protruding portion 152; bottom wall 152A; peripheral wall 152B; welding mark 160; first welding mark 161; second welding mark 162; intermediate region 170; circumferential region 180; first body portion 210; second body portion 220; first plate 221; second plate 222; adapter 230; first annular groove 240. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.

[0017] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0018] Reference to "embodiment" in this application means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase may not necessarily refer to the same embodiment when it appears in various places in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0019] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled", and "attached" 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, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0020] The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0021] The term "plurality" as used in this application refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0022] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0023] In some embodiments, the battery may be a battery pack. The battery pack includes a battery case and battery cells, and the battery cells or battery modules are accommodated in the battery case.

[0024] In some embodiments, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be activated by charging after discharging to continue to be used. The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0025] With the development and maturity of battery technology, the scope of application of battery technology is becoming more and more extensive, such as electric vehicles, small electric drones and other electrical equipment. For electrical equipment, battery technology is an important factor related to its development. The quality of battery production and manufacturing is closely related to the service life and quality of electrical equipment. Therefore, it is crucial to ensure the quality of battery production and manufacturing.

[0026] The battery includes tabs and terminals. The tab is a key part of the battery. It leads out the positive and negative electrodes from the battery cell and serves as a metal conductor, which is the contact point during battery charging and discharging. The terminal is the two interfaces of the battery, one is the positive electrode and the other is the negative electrode. They are the polar positions connecting the battery and the external circuit. The tab and the terminal (electrode terminal) are usually connected together by welding to establish an electrical connection relationship, so that the energy of the battery cell flows to the outside.

[0027] However, in the related art, during the welding process of the tab and the terminal, it is easy to generate tab bulges, which cause tab tearing and reduce the reliability of the battery during the manufacturing process.

[0028] In view of this, in order to solve the technical problem that tab tearing is easily caused during the welding process of the tab and the terminal, and at the same time improve the reliability of battery production and manufacturing, some embodiments of the present application provide a battery cell and an electrical equipment. The battery cell includes a housing, an electrode terminal, an electrode assembly, a tab and a metal sheet.

[0029] The housing has a first wall, on which an electrode terminal is provided. An electrode assembly is disposed inside the housing, and a tab is disposed inside the housing. The tab has a first end and a second end. The first end is connected to the electrode assembly, and the second end is disposed between the metal sheet and the electrode terminal. The metal sheet, the second end, and the electrode terminal are welded and fixed. Wherein, the metal sheet includes a body portion and a protrusion portion. The protrusion portion protrudes towards the electrode terminal relative to the body portion. The protrusion portion includes a bottom wall and a peripheral wall. The peripheral wall surrounds the outer peripheral edge of the bottom wall and connects the bottom wall and the body portion. A welding mark is provided on the bottom wall. The minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D. The hardness of the metal sheet is A, and the thickness of the tab is D, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

[0030] In the above solution, the second end is disposed between the metal sheet and the electrode terminal, which can provide buffering for the welding of the electrode terminal and the tab, reducing the probability of the tab being torn. The minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D. The hardness of the metal sheet is A, and the thickness of the tab is D, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB. In this way, while reducing the probability of the tab being torn, the current between the electrode terminal and the tab can be ensured.

[0031] The battery disclosed in the embodiment of the present application can be but is not limited to being used in vehicles, and can also be used in other electrical devices with structural beams, wherein the battery can be arranged to avoid the structural beams of other electrical devices.

[0032] The battery disclosed in the embodiment of the present application can be but is not limited to being used in electrical devices such as vehicles, ships, or aircrafts with longitudinal beams, and can enable the battery to avoid the structural beams. The power supply system of the electrical device can be composed of the batteries disclosed in the present application.

[0033] The electrode terminal disclosed in the embodiment of the present application can be a pole column, and the electrode assembly can be a battery cell. One end of the electrode terminal is electrically connected to the bus bar, and the other end is electrically connected to the tab.

[0034] The electrode assembly disclosed in the embodiment of the present application can be a unit formed by winding or laminating a stacked portion. The stacked portion includes a first electrode, a separator, and a second electrode. When the first electrode is a positive electrode, the second electrode is a negative electrode.

[0035] The embodiment of the present application provides an electrical device using a battery as a power source. The electrical device can be but is not limited to mobile phones, tablet computers, laptop computers, electric toys, power tools, electric bicycles, electric motorcycles, electric vehicles, ships, heavy trucks, buses, spacecrafts, etc. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0036] For the convenience of description, the following embodiments will take an electric device in an embodiment of the present application as a vehicle as an example for illustration.

[0037] The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The type of the vehicle can be a sedan, an off-road vehicle, a heavy truck or a bus, etc. A battery is arranged inside the vehicle, and the battery can be arranged at the bottom, the head or the tail of the vehicle. The battery can be used for power supply of the vehicle. For example, the battery can be used as the operating power source of the vehicle for the vehicle's circuit system, such as for the working power requirements during vehicle startup, navigation and operation.

[0038] The vehicle can also include a controller and a motor. The controller is used to control the battery to supply power to the motor. For example, it is used for the working power requirements during vehicle startup, navigation and driving.

[0039] In some embodiments of the present application, the battery can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0040] An embodiment of the present application provides a battery cell 100A. Please refer to Figures 1 to 3 , Figure 1 which is an exploded structural schematic diagram of the battery cell 100A provided by an embodiment of the present application; Figure 2 shows the positional relationship among the metal sheet 150, the electrode terminal 120 and the tab 140 in an embodiment of the present application; Figure 3 shows the structure of the welding mark 160 and the metal sheet 150 in an embodiment of the present application.

[0041] The battery cell 100A includes a housing 110, an electrode terminal 120, an electrode assembly 130, a tab 140, and a metal sheet 150. The housing 110 has a first wall 111. The electrode terminal 120 is disposed on the first wall 111. The electrode assembly 130 is disposed within the housing 110. The tab 140 extends from an end of the electrode assembly 130 and is electrically connected to the electrode terminal 120. The tab 140 is disposed within the housing 110 and has a first end 141 and a second end 142. The first end 141 is connected to the electrode assembly 130, and the second end 142 is disposed between the metal sheet 150 and the electrode terminal 120. The metal sheet 150, the second end 142, and the electrode terminal 120 are welded and fixed. Wherein, the metal sheet 150 includes a body portion 151 and a protruding portion 152. The protruding portion 152 protrudes toward the electrode terminal 120 relative to the body portion 151. The protruding portion 152 includes a bottom wall 152A and a peripheral wall 152B. The peripheral wall 152B surrounds the outer peripheral edge of the bottom wall 152A and connects the bottom wall 152A and the body portion 151. A welding mark 160 is provided on the bottom wall 152A. The minimum distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is D. The hardness of the metal sheet 150 is A, and the thickness of the tab 140 is D, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB.

[0042] The battery cell 100A includes a housing 110, an electrode terminal 120, an electrode assembly 130, a tab 140, and a metal sheet 150. The battery cell 100A is connected to an external electrical device through the electrode terminal 120. Inside the battery cell 100A, that is, inside the housing 110, the electrode terminal 120 is electrically connected to the electrode assembly 130 through the tab 140, thereby playing a role in supplying power to the electrical device. The housing 110 has a first wall 111. The electrode terminal 120 is disposed on the first wall 111. The electrode terminal 120 penetrates both sides of the first wall 111. That is to say, the electrode terminal 120 can not only be connected to an external electrical device but also to the internal electrode assembly 130. The tab 140 has a first end 141 and a second end 142. The first end 141 is connected to the electrode assembly 130, and the second end 142 is disposed between the metal sheet 150 and the electrode terminal 120. That is to say, a part of the tab 140 is disposed between the metal sheet 150 and the electrode terminal 120, and another part of the tab 140 is connected to the electrode assembly 130.

[0043] The metal sheet 150, the second end 142 and the electrode terminal 120 are welded and fixed. Exemplarily, the metal sheet 150, the second end 142 and the electrode terminal 120 can be welded together by torque welding. The metal sheet 150 is the direct contact point of torque welding. If the tab 140 and the electrode terminal 120 are directly welded together by torque welding on the tab 140 side, it will cause tearing of the tab 140. Therefore, the second end 142 is arranged between the metal sheet 150 and the electrode terminal 120, which can reduce the direct contact between the welding and the tab 140, thus causing damage to the tab 140, reducing the probability of failure of the battery cell 100A during the manufacturing process, and improving the quality of the battery cell 100A.

[0044] The metal sheet 150 includes a body portion 151 and a protrusion portion 152. The protrusion portion 152 protrudes towards the electrode terminal 120 relative to the body portion 151. In fact, the protrusion of the protrusion portion 152 also faces the tab 140. During the process of welding the tab 140 and the electrode terminal 120, the welding head applies pressure to the metal sheet 150. Under the action of the pressure, the metal sheet 150 will squeeze towards the second end 142 of the tab 140, thereby forming the protrusion portion 152 of the metal sheet 150. The protrusion portion 152 of the metal sheet 150 includes a bottom wall 152A and a peripheral wall 152B. The peripheral wall 152B surrounds the outer peripheral edge of the bottom wall 152A and connects the bottom wall 152A and the body portion 151. This can provide a buffering effect between the metal sheet 150 and the tab 140, reducing the probability of the tab 140 being torn.

[0045] Since a welding mark 160 will be formed when the metal sheet 150 is welded to the tab 140, the welding mark 160 is provided on the bottom wall 152A, and the minimum distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is D. The area where the distance D is located is the area not covered by the welding mark 160. The hardness of the metal sheet 150 is A, and the thickness of the tab 140 is the thickness of the tab 140, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB. For example, D*W / A can be equal to 0.0015 mm² / HB, 0.002 mm² / HB, 0.0025 mm² / HB, 0.003 mm² / HB, 0.004 mm² / HB, 0.005 mm² / HB, 0.006 mm² / HB, 0.008 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.15 mm² / HB, 0.2 mm² / HB, 0.25 mm² / HB, 0.3 mm² / HB, etc. During the welding process, a protrusion 152 will be formed on the metal sheet 150. When the minimum distance D between the welding mark 160 and the outer peripheral edge of the bottom wall 152A and the thickness W of the tab 140 remain unchanged, if the hardness of the metal sheet 150 is too high, then during the protrusion process of the metal sheet 150, stress concentration may be caused to the tab 140, which may further lead to tearing of the tab 140. If the hardness of the metal sheet 150 is too low, it may cause the metal sheet 150 to fail to perform the buffering function of assisting welding and prevent the tab 140 from tearing. When the thickness W of the tab 140 and the hardness A of the metal sheet 150 remain unchanged, the closer the distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is, the greater the pressing force of the peripheral edge of the bottom wall 152A of the metal sheet 150 on the tab 140, and the easier it is to cause tearing or damage to the tab 140. However, if the distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is too far, it will result in too small an effective area of welding (i.e., the total area where the tab 140 is connected to the electrode terminal 120 through the welding mark 160), which will affect the current flow between the tab 140 and the electrode terminal 120. When the hardness A of the metal sheet 150 and the minimum distance D between the welding mark 160 and the outer peripheral edge of the bottom wall 152A remain unchanged, if the tab 140 is too thick, the function of torque welding (resistance welding) may not be exerted, and the tab 140 and the electrode terminal 120 cannot be welded together. If the thickness of the tab 140 is too small, on the one hand, it may cause the welding between the tab 140 and the electrode terminal 120 to be not firm and easily cause tearing of the tab 140. On the other hand, if the thickness of the tab 140 is too small, it will cause an increase in the internal resistance of the battery cell 100A, thereby reducing the output capacity and efficiency of the battery cell 100A.

[0046] The minimum distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is D, the hardness of the metal sheet 150 is A, and the thickness of the tab 140 is W, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB. For example, D * W / A can be equal to 0.0015 mm² / HB, 0.002 mm² / HB, 0.0025 mm² / HB, 0.003 mm² / HB, 0.004 mm² / HB, 0.005 mm² / HB, 0.006 mm² / HB, 0.008 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.15 mm² / HB, 0.2 mm² / HB, 0.25 mm² / HB, 0.3 mm² / HB, etc. It can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0047] In some embodiments, the tab 140 can be directly connected to the electrode terminal 120, or the tab 140 and the electrode terminal 120 can be electrically connected through an adapter 230.

[0048] In this embodiment, 15 HB ≤ A ≤ 60 HB.

[0049] Exemplarily, the value of A can be 15 HB, 16 HB, 17 HB, 19 HB, 20 HB, 25 HB, 26 HB, 30 HB, 40 HB, 45 HB, 50 HB, 55 HB, 58 HB, 60 HB, etc. On the one hand, the hardness of the metal sheet 150 is sufficient to meet the stability of the welding connection between the auxiliary tab 140 and the electrode terminal 120, ensuring the welding quality of the tab 140 and the electrode terminal 120. On the other hand, the thickness of the metal sheet 150 is not too small, resulting in the metal sheet 150 being unable to play a buffering role in assisting welding, and thus causing the tab 140 to be torn. Therefore, 15 HB ≤ A ≤ 60 HB improves the manufacturing quality of the battery cell 100A, reduces the probability of the battery cell 100A malfunctioning, and improves the reliability of use of the battery cell 100A.

[0050] Please refer to Figures 1 to 3 , in this embodiment, 0.3 mm ≤ D ≤ 1.5 mm.

[0051] Exemplarily, the size of D can be 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc. On the one hand, the minimum distance D between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is sufficient to meet the over-current between the electrode terminal 120 and the tab 140, ensure the performance of the battery cell 100A, ensure the stable operation of the battery cell 100A, and facilitate the stable transmission of current. On the other hand, it can avoid the minimum distance D between the welding mark 160 and the outer peripheral edge of the bottom wall 152A from being too close, so as to prevent the formation of a convex bulge between the outer peripheral edge of the bottom wall 152A and the tab 140, which may cause the tab 140 to tear. Therefore, 0.3 mm ≤ D ≤ 1.5 mm, which improves the manufacturing quality of the battery cell 100A, reduces the probability of the battery cell 100A malfunctioning, and improves the reliability of use of the battery cell 100A.

[0052] Please refer to Figures 1 to 3 , in this embodiment, 0.3 mm ≤ W ≤ 3 mm.

[0053] Exemplarily, the size of W can be 0.3 mm, 0.4 mm, 0.6 mm, 0.9 mm, 1.2 mm, 1.3 mm, 1.6 mm, 1.8 mm, 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 2.9 mm, 3 mm. Setting the thickness of the tab to W improves the manufacturing quality of the battery cell 100A, reduces the probability of the battery cell 100A malfunctioning, and improves the reliability of use of the battery cell 100A.

[0054] Please refer to Figures 1 to 3 , in this embodiment, along the thickness direction of the second end 142, the projection of the bottom wall 152A is configured as a circle, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.28 mm² / HB.

[0055] Along the thickness direction of the second end 142, the projection of the bottom wall 152A is configured as a circle. That is to say, along the thickness direction of the second end 142, the projection of the bottom wall 152A on the tab 140 is a circle, and the shape of the contact surface between the bottom wall 152A and the tab 140 is a circle. On the one hand, the circular contact surface can provide a larger contact area, reduce the resistance encountered by the current during transmission, help reduce energy loss, and improve the current transmission efficiency. On the other hand, the circular contact surface is easier to achieve precise control and processing during manufacturing, reducing the production and manufacturing costs. Moreover, during the formation of the raised portion 152 on the metal sheet 150, the circular bottom wall 152A can reduce the stress generation of the tab 140 and reduce the probability of the tab 140 tearing.

[0056] Exemplarily, when the projection of the bottom wall 152A is circular along the thickness direction of the second end 142, the value of D*W / A can be 0.0015 mm² / HB, 0.0018 mm² / HB, 0.002 mm² / HB, 0.11 mm² / HB, 0.15 mm² / HB, 0.20 mm² / HB, 0.22 mm² / HB, 0.23 mm² / HB, 0.25 mm² / HB, 0.28 mm² / HB, etc. It can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0057] Please refer to Figures 1 to 3 , in this embodiment, along the thickness direction of the second end 142, the projection of the bottom wall 152A is square, satisfying: 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

[0058] For example, D*W / A can be 0.0018 mm² / HB, 0.002 mm² / HB, 0.003 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.11 mm² / HB, 0.12 mm² / HB, 0.13 mm² / HB, 0.15 mm² / HB, 0.16 mm² / HB, 0.17 mm² / HB, 0.18 mm² / HB, 0.19 mm² / HB, 0.20 mm² / HB, 0.21 mm² / HB, 0.22 mm² / HB, 023 mm² / HB, 0.24 mm² / HB, 0.25 mm² / HB, 0.26 mm² / HB, 0.27 mm² / HB, 0.28 mm² / HB, 0.29 mm² / HB, 0.30 mm² / HB, etc. The shape of the contact surface between the bottom wall 152A and the tab 140 is square. Compared with a circle, a square is more likely to generate stress concentration. Therefore, the minimum distance D between the square weld mark 160 and the outer periphery of the bottom wall 152A needs to be set farther compared with a circle. Thus, along the thickness direction of the second end 142, the projection of the bottom wall 152A is square, satisfying: 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB, which can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0059] Please refer to Figures 1 to 3, in this embodiment, the bottom wall 152A includes an intermediate region 170 and a circumferential region 180. The circumferential region 180 is disposed around the intermediate region 170. There are multiple welding imprints 160, including a first welding imprint 161 and a second welding imprint 162. The first welding imprint 161 is disposed in the circumferential region 180, and the second welding imprint 162 is disposed in the intermediate region 170. The depth of the first welding imprint 161 is less than the depth of the second welding imprint 162.

[0060] The bottom wall 152A includes an intermediate region 170 and a circumferential region 180. The circumferential region 180 is disposed around the intermediate region 170. That is to say, the intermediate region 170 is enveloped by the circumferential region 180. There are multiple welding imprints 160, which can enhance the connection strength between the tab 140 and the electrode terminal 120, improve the welding quality of the tab 140 and the electrode terminal 120, and increasing the number of welding imprints 160 means that the heat and pressure during the welding process between the tab 140 and the electrode terminal 120 can be dispersed, reducing the probability of stress concentration occurring in the tab 140 and the electrode terminal 120, improving the manufacturing quality of the battery cell 100A, and improving the reliability of use of the battery cell 100A.

[0061] The multiple welding imprints 160 include a first welding imprint 161 and a second welding imprint 162. The multiple first welding imprints 161 can be evenly and spacedly disposed in the circumferential region 180, and the multiple second welding imprints 162 can be evenly and spacedly disposed in the intermediate region 170. The multiple first welding imprints 161 envelop the multiple second welding imprints 162. The depth of the first welding imprint 161 is less than the depth of the second welding imprint 162. In fact, it means that the welding strength (connection strength) between the tab 140 and the electrode terminal 120 at the second welding imprint 162 is greater than that of the first welding imprint 161. Since during the auxiliary welding process of the metal sheet 150, the stress generated between the metal sheet 150 and the tab 140 is mainly concentrated at the periphery of the bottom wall 152A and the tab 140, then reducing the depth of the first welding imprint 161 can reduce the stress between the metal sheet 150 at the periphery of the bottom wall 152A and the tab 140, and further reduce the probability of the tab 140 being torn.

[0062] And the depth of the second welding imprint 162 is greater than the depth of the first welding imprint 161. That is to say, the welding strength between the metal sheet 150 and the tab 140 in the intermediate region 170 is greater, which can enhance the stability and reliability of the connection between the metal sheet 150 and the tab 140, and further improve the stability and reliability of the operation of the battery cell 100A.

[0063] Please refer to Figures 1 to 3 , in this embodiment, along the thickness direction of the second end 142, the projection of the first welding imprint 161 is circular, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.28 mm² / HB.

[0064] For example, D*W / A can be 0.0015 mm² / HB, 0.0016 mm² / HB, 0.0017 mm² / HB, 0.0018 mm² / HB, 0.002 mm² / HB, 0.003 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.11 mm² / HB, 0.12 mm² / HB, 0.13 mm² / HB, 0.15 mm² / HB, 0.16 mm² / HB, 0.17 mm² / HB, 0.18 mm² / HB, 0.19 mm² / HB, 0.20 mm² / HB, 0.21 mm² / HB, 0.22 mm² / HB, 0.23 mm² / HB, 0.24 mm² / HB, 0.25 mm² / HB, 0.26 mm² / HB, 0.27 mm² / HB, 0.28 mm² / HB, etc. Along the thickness direction of the second end 142, the projection of the first welding mark 161 is circular, and the shape of the first welding mark 161 is circular. The circular welding mark 160 helps to reduce stress concentration. Since the first welding mark 161 is arranged in the circumferential area 180 of the bottom wall 152A and is close to the periphery of the bottom wall 152A, the first welding mark 161 is set to be circular, which can reduce the probability of the tab 140 being torn or damaged. Thus, along the thickness direction of the second end 142, the projection of the first welding mark 161 is circular, satisfying 0.0015 mm² / HB ≤ D*W / A ≤ 0.28 mm² / HB, which can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0065] In some embodiments, when the first welding mark 161 is circular, the second welding mark 162 can be square or circular.

[0066] Please refer to Figures 1 to 3 , in this embodiment, along the thickness direction of the second end 142, the projection of the first welding mark 161 is square, satisfying 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

[0067] For example, D*W / A can be 0.0018 mm² / HB, 0.002 mm² / HB, 0.003 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.11 mm² / HB, 0.12 mm² / HB, 0.13 mm² / HB, 0.15 mm² / HB, 0.16 mm² / HB, 0.17 mm² / HB, 0.18 mm² / HB, 0.19 mm² / HB, 0.20 mm² / HB, 0.21 mm² / HB, 0.22 mm² / HB, 023 mm² / HB, 0.24 mm² / HB, 0.25 mm² / HB, 0.26 mm² / HB, 0.27 mm² / HB, 0.28 mm² / HB, 0.29 mm² / HB, 0.30 mm² / HB, etc. The shape of the contact surface between the bottom wall 152A and the tab 140 is square. Compared with a circle, a square is more likely to generate stress concentration. Therefore, the minimum distance D between the square weld mark 160 and the outer peripheral edge of the bottom wall 152A needs to be set farther compared with a circle. Along the thickness direction of the second end 142, the projection of the first weld mark 161 is square, satisfying 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB. It can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0068] In some embodiments, when the first weld mark 161 is circular, the second weld mark 162 can be square or circular.

[0069] Please refer to Figures 1 to 3 , in this embodiment, the contact area between the weld mark 160 and the tab 140 is S1, 20 mm² ≤ S1 ≤ 120 mm², 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

[0070] For example, S1 can be 20 mm², 30 mm², 40 mm², 50 mm², 60 mm², 70 mm², 80 mm², 90 mm², 100 mm², 110 mm², 120 mm², etc. D*W / A can be 0.0015 mm² / HB, 0.0016 mm² / HB, 0.0017 mm² / HB, 0.0018 mm² / HB, 0.002 mm² / HB, 0.003 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.11 mm² / HB, 0.12 mm² / HB, 0.13 mm² / HB, 0.15 mm² / HB, 0.16 mm² / HB, 0.17 mm² / HB, 0.18 mm² / HB, 0.19 mm² / HB, 0.20 mm² / HB, 0.21 mm² / HB, 0.22 mm² / HB, 023 mm² / HB, 0.24 mm² / HB, 0.25 mm² / HB, 0.26 mm² / HB, 0.27 mm² / HB, 0.28 mm² / HB, 0.29 mm² / HB, 30 mm² / HB, etc.

[0071] The larger the contact area between the welding mark 160 and the tab 140, the greater the welding strength of the connection between the tab 140 and the metal sheet 150 and between the tab 140 and the electrode terminal 120. Within a certain range, the larger the contact area between the welding mark 160 and the tab 140, the more stable the connection between the tab 140 and the metal sheet 150 and between the tab 140 and the electrode terminal 120. The contact area between the welding mark 160 and the tab 140 is S1, S1≥W1; F1≤D*W / A≤F2, which can enhance the stability of the connection between the tab 140 and the electrode terminal 120, while reducing the probability of the tab 140 being torn or damaged, improving the quality of the battery cell 100A, and improving the use stability and reliability of the battery cell 100A.

[0072] Please refer to Figures 1 to 3 , in this embodiment, the bottom wall 152A has a first side facing away from the electrode terminal 120, and a first annular groove 240 is provided on the first side, and the first annular groove 240 surrounds the outer periphery of the welding mark 160.

[0073] During the welding process, the welding head will exert a certain pressure on the metal sheet 150. Therefore, a certain depression will also occur between the welding mark 160 and the tab 140. While the outer peripheral edge of the welding mark 160 causes the tab 140 to form a depression, it is easy to form a bulge on the tab 140. If a welding mark 160 is formed again at the position of the bulge, it is easy to tear the tab 140, resulting in damage to the tab 140. Therefore, the bottom wall 152A has a first side facing away from the electrode terminal 120, and a first annular groove 240 is provided on the first side. The first annular groove 240 surrounds the outer peripheral edge of the welding mark 160, which can effectively reduce the probability of the tab 140 forming a bulge, enhance the stability of the connection between the tab 140 and the electrode terminal 120, and at the same time reduce the probability of the tab 140 being torn or damaged, improve the quality of the battery cell 100A, and improve the use stability and reliability of the battery cell 100A.

[0074] Please refer to Figures 1 to 3 , in this embodiment, both the welding mark 160 and the first annular groove 240 are multiple and correspond one by one. The minimum distance between two adjacent first annular grooves 240 is f, satisfying: 0.5 mm ≤ f ≤ 3 mm.

[0075] For example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.5 mm, 2.6 mm, 3.0 mm, etc. Both the welding mark 160 and the first annular groove 240 are multiple and correspond one by one. That is to say, a first annular groove 240 is provided on the outer peripheral edge of each welding mark 160. The minimum distance between two adjacent first annular grooves 240 is f, satisfying: 0.5 mm ≤ f ≤ 3 mm, which can enhance the stability of the connection between the tab 140 and the electrode terminal 120, and at the same time reduce the probability of the tab 140 being torn or damaged, improve the quality of the battery cell 100A, and improve the use stability and reliability of the battery cell 100A.

[0076] Please refer to Figures 1 to 3 , in this embodiment, the contact area between the welding mark 160 and the tab 140 is S1, and the area of the first annular groove 240 is S3, satisfying 2.5 ≤ S1 / S3 ≤ 240.

[0077] For example, S1 / S3 can be 2.5, 3, 6, 9, 10, 25, 30, 35, 60, 80, 90, 100, 110, 120, 140, 150, 160, 180, 190, 220, 230, 240, etc. A first annular groove 240 is provided around the weld mark 160 to reduce the probability of the tab 140 being torn and reduce the stress concentration of the tab 140. If S1 / S3 is too large, it means that the area of the first annular groove 240 is too small, which is not conducive to reducing the stress concentration of the tab 140. If S1 / S3 is too large, it means that the contact area between the weld mark 160 and the tab 140 is too small, which will affect the fixed connection area between the tab 140 and the electrode terminal 120 to be too small, thereby increasing the resistance inside the battery cell 100A and reducing the current-carrying capacity of the tab 140, and further reducing the battery current output capacity. Therefore, the contact area between the weld mark 160 and the tab 140 is S1, and the area of the first annular groove 240 is S3, satisfying 2.5 ≤ S1 / S3 ≤ 240, which can enhance the connection stability between the tab 140 and the electrode terminal 120, while reducing the probability of the tab 140 being torn or damaged, improving the quality of the battery cell 100A, and improving the use stability and reliability of the battery cell 100A.

[0078] Please refer to Figures 1 to 3 , in this embodiment, the body portion 151 includes a first body portion 210 and a second body portion 151. The second body portion 151 surrounds the outer periphery of the first body portion 210. The first body portion 210 connects the second body portion 151 and the protrusion portion 152. The second body portion 151 bends away from the tab 140.

[0079] The metal sheet 150 includes a body portion 151 and a protrusion portion 152. The body portion 151 includes a first body portion 210 and a second body portion 151. The second body portion 151 surrounds the outer periphery of the first body portion 210. That is to say, the second body portion 151 is disposed outside the first body portion 210, and the first body portion 210 is disposed inside the second body portion 151. The second body portion 151 and the protrusion portion 152 are connected through the first body portion 210. The second body portion 151 bends away from the tab 140. Actually, it is also the outer periphery of the metal sheet 150 that bends away from the tab 140. This can reduce the probability of the second body portion 151 (the edge of the metal sheet 150) rubbing against the tab 140, reduce the probability of the tab 140 being damaged, improve the quality of the battery cell 100A, and improve the use stability and reliability of the battery cell 100A.

[0080] Please refer to Figure 4 , in this embodiment, along the thickness direction of the second end 142, a part of the projection of the second body portion 151 overlaps with the projection of the first body portion 210.

[0081] During the assembly and manufacturing process of the battery cell 100A, when the battery cores are combined, the second body portion 151 of the metal sheet 150 is likely to cut other components inside the battery cell 100A, such as the ear 140, the electrode terminal 120, or the plastic separator.

[0082] The second body portion 151 has a first plate 221 and a second plate 222. The first plate 221 is perpendicular to the second plate 222. The second plate 222 is connected to the first body portion 210 through the first plate 221. Along the thickness direction of the second end 142, a part of the projection of the second body portion 151 overlaps with the projection of the first body portion 210. That is to say, along the thickness direction of the second end 142, the projection of the second plate 222 overlaps with the projection of the first body portion 210. This can reduce the probability of the second body cutting other components inside the battery during battery assembly, improve the battery assembly quality, and improve the operation stability and use reliability of the battery cell 100A.

[0083] Please refer to Figures 1 to 3 , in this embodiment, the metal sheet 150 is configured as a circular metal sheet 150.

[0084] Compared with setting the metal sheet 150 as a square, the circular metal sheet 150 has no sharp corners, which can reduce the probability of the metal sheet 150 scratching the ear 140 or other components inside the battery cell 100A, reduce the probability of the ear 140 being damaged, improve the quality of the battery cell 100A, and improve the use stability and reliability of the battery cell 100A.

[0085] Please refer to Figures 1 to 3 , in this embodiment, the ear 140, the electrode terminal 120, and the metal sheet 150 are fixedly connected by ultrasonic welding.

[0086] The ear 140, the electrode terminal 120, and the metal sheet 150 are fixedly connected by ultrasonic welding. On the one hand, the stability and reliability of ultrasonic welding are high, which can improve the connection stability of the ear 140, the electrode terminal 120, and the metal sheet 150. On the other hand, ultrasonic welding has an extremely high welding speed, which can significantly improve the production efficiency in mass production operations and increase the production rate of the battery cell 100A.

[0087] Moreover, during the ultrasonic welding process, no connecting bolts, nails, adhesives, or welding materials are required, so no smoke, harmful gases, or pollutants are generated. This is not only beneficial to environmental protection but also reduces the health risks of workers. Compared with other welding processes, ultrasonic welding has lower costs. On the one hand, the ultrasonic welding equipment is simple, and the mold design is relatively easy, enabling rapid mold change, which increases the utilization rate and versatility of the equipment. On the other hand, since the welding time is short, no complex ventilation system is required to remove smoke, and no cooling system is required to remove excess heat, thus saving energy.

[0088] Please refer to Figures 1 to 4 , this embodiment of the present application also provides an electrical device, which includes the battery cell 100A described in any one of the embodiments of the present application.

[0089] In the electrical device proposed in the embodiment of the present application, the minimum distance between the welding mark 160 and the outer peripheral edge of the bottom wall 152A is D, the hardness of the metal sheet 150 is A, and the thickness of the tab 140 is W, satisfying: 0.0015 mm² / HB ≤ D * W / A ≤ 0.3 mm² / HB. For example, D * W / A can be 0.0015 mm² / HB, 0.002 mm² / HB, 0.0025 mm² / HB, 0.003 mm² / HB, 0.004 mm² / HB, 0.005 mm² / HB, 0.006 mm² / HB, 0.008 mm² / HB, 0.01 mm² / HB, 0.02 mm² / HB, 0.05 mm² / HB, 0.1 mm² / HB, 0.15 mm² / HB, 0.2 mm² / HB, 0.25 mm² / HB, 0.3 mm² / HB, etc. It can effectively reduce the probability of the tab 140 being torn under the condition of meeting the performance of the battery cell 100A (good current flow between the tab 140 and the electrode terminal 120), improve the stability of the connection between the tab 140 and the electrode terminal 120, and improve the manufacturing quality of the battery cell 100A.

[0090] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements but also includes other elements not expressly listed, or also includes elements inherent to such process, method, commodity or device. Without further limitations, the element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, commodity or device including the said element.

[0091] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for the relevant parts, reference can be made to the description of the method embodiment.

[0092] The above description is only for the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the scope of the claims of the present application.

[0093] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing having a first wall; An electrode terminal disposed on the first wall; An electrode assembly disposed within the housing; A tab extending from an end of the electrode assembly and electrically connected to the electrode terminal, disposed within the housing, the tab having a first end and a second end, the first end being connected to the electrode assembly; A metal sheet, the second end being disposed between the metal sheet and the electrode terminal, the metal sheet, the second end and the electrode terminal being welded and fixed; Wherein, the metal sheet includes a body portion and a protruding portion, the protruding portion protrudes towards the electrode terminal relative to the body portion, the protruding portion includes a bottom wall and a peripheral wall, the peripheral wall surrounds the outer peripheral edge of the bottom wall and connects the bottom wall and the body portion, a welding mark is provided on the bottom wall, the minimum distance between the welding mark and the outer peripheral edge of the bottom wall is D, the hardness of the metal sheet is A, and the thickness of the tab is W, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB, 15 HB ≤ A ≤ 60 HB, 0.3 mm ≤ D ≤ 1.5 mm, 0.3 mm ≤ W ≤ 3 mm.

2. The battery cell according to claim 1, wherein In the thickness direction of the second end, the projection of the bottom wall is configured as a circle, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.28 mm² / HB.

3. The battery cell according to claim 1, characterized in that, In the thickness direction of the second end, the projection of the bottom wall is configured as a square, satisfying: 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

4. The battery cell according to claim 1, wherein The bottom wall includes an intermediate region and a circumferential region, the circumferential region is disposed around the intermediate region; The welding marks are multiple and include a first welding mark and a second welding mark, the first welding mark is disposed in the circumferential region, the second welding mark is disposed in the intermediate region, and the depth of the first welding mark is less than the depth of the second welding mark.

5. The battery cell according to claim 4, wherein In the thickness direction of the second end, the projection of the first welding mark is a circle, satisfying: 0.0015 mm² / HB ≤ D*W / A ≤ 0.28 mm² / HB.

6. The battery cell according to claim 4, wherein, In the thickness direction of the second end, the projection of the first welding mark is a square, satisfying: 0.0018 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

7. The battery cell according to claim 1, characterized in that, The contact area between the welding mark and the tab is S1, 20 mm² ≤ S1 ≤ 120 mm²; 0.0015 mm² / HB ≤ D*W / A ≤ 0.3 mm² / HB.

8. The battery cell according to claim 1, wherein The bottom wall has a first side facing away from the electrode terminal, and a first annular groove is provided on the first side, and the first annular groove surrounds the outer peripheral edge of the welding mark.

9. The battery cell according to claim 8, wherein, The welding marks and the first annular grooves are both multiple and correspond one by one, and the minimum distance between two adjacent first annular grooves is f, satisfying: 0.5 mm ≤ f ≤ 3 mm.

10. The battery cell according to claim 8, characterized in that, The contact area between the welding mark and the tab is S1, and the area of the first annular groove is S3, satisfying: 20 mm² ≤ S1 ≤ 120 mm², 2.5 ≤ S1 / S3 ≤ 240.

11. The battery cell according to claim 1, wherein, The body part includes a first body part and a second body part. The second body part surrounds the outer periphery of the first body part. The first body part connects the second body part and the convex part. The second body part is bent away from the tab.

12. The battery cell according to claim 11, wherein, In the thickness direction of the second end, a part of the projection of the second body part overlaps with the projection of the first body part.

13. The battery cell according to claim 1, wherein The metal sheet is configured as a circular metal sheet.

14. The battery cell according to claim 1, wherein The tab, the electrode terminal, and the metal sheet are fixedly connected by ultrasonic welding.

15. An electrical device, which includes the battery cell according to any one of claims 1-14.

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