Battery cell, battery device, and electric device

Abstract

The embodiment of the application provides a battery monomer, a battery device and an electric equipment, and belongs to the technical field of battery devices. The battery monomer comprises a shell, has a first wall; an electrode assembly comprising a main body part and a first tab, the first tab being located at one end of the main body part close to the first wall; a first current collector arranged between the first wall and the first tab and electrically connected with the first tab; wherein a part of the first wall protrudes towards the first current collector to form a first protruding part, the first protruding part comprises an end wall and a side wall, the side wall and the end wall enclose a first recess, the end wall is welded with the first current collector to form a first welding mark, and the end wall is provided with a liquid injection hole; the battery monomer further comprises a first sealing piece and a second sealing piece, the first sealing piece blocks the liquid injection hole, the second sealing piece is at least partially accommodated in the first recess, the edge of the second sealing piece is welded with the side wall, and the second sealing piece, the side wall and the end wall enclose a first cavity, so that the sealing effect of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of battery device technology, specifically to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] In battery device technology, the reliability of individual battery cells is a crucial issue. Therefore, improving the reliability of individual battery cells is a pressing technical problem that needs to be solved in battery device technology. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device to improve the sealing effect of the battery cell, thereby improving the reliability of the battery device.

[0005] In a first aspect, this application provides a battery cell, comprising: a housing having a first wall in a first direction; an electrode assembly disposed within the housing, the electrode assembly including a main body and a first tab, the first tab being located at one end of the main body near the first wall; a first current collector disposed between the first wall and the first tab, and electrically connected to the first tab; wherein a portion of the first wall protrudes toward the first current collector to form a first protrusion, the first protrusion including an end wall and a side wall disposed around the end wall, the side wall and the end wall forming a first groove, the end wall being welded to the first current collector to form a first weld mark, and the end wall having an injection hole; the battery cell further includes a first seal and a second seal, the first seal sealing the injection hole, the second seal being at least partially received within the first groove, the edge of the second seal being welded to the side wall, and the second seal, the side wall, and the end wall forming a first cavity.

[0006] In the technical solution of this application embodiment, a first protrusion composed of an end wall and a side wall is formed on the first wall. On the one hand, by forming an injection hole on the end wall and sealing the injection hole with a first sealing member, the injection hole is sealed. On the other hand, the welding position between the first wall and the first current collector is set on the end wall. Thus, both the first weld mark and the injection hole are located on the end wall. At this time, by welding the second sealing member to the side wall, the injection hole can be further sealed, and the first cavity formed by the second sealing member, the side wall, and the end wall can also be sealed. This allows the gas leaking from the first weld mark when the internal gas pressure of the battery cell is high to be contained in the first cavity, balancing the internal gas pressure of the battery cell. This battery cell has the injection hole and the first weld mark simultaneously located on the end wall, and the sealing effect of the battery cell can be improved by the setting of the second sealing member, thereby improving the performance and service life of the power battery device.

[0007] In an optional embodiment, the second seal is provided with a stress relief groove, which is arranged in a ring shape along the edge of the second seal.

[0008] When the second seal is welded to the side wall, the weld edge of the second seal is easily stretched due to the welding process. By setting an annular stress relief groove on the edge of the second seal, the second seal can undergo tensile deformation at the stress relief groove, thereby releasing the stress generated by the welding.

[0009] In an optional embodiment, the inner circumferential surface of the sidewall is provided with a stepped surface, and the second seal abuts against the stepped surface along the first direction.

[0010] By providing a stepped surface on the inner circumferential surface of the sidewall, and enabling the second seal to abut against the stepped surface in the first direction, the second seal can be positioned by lapping before welding through the stepped surface, so as to facilitate subsequent welding.

[0011] In an optional embodiment, the orthographic projection of the second seal overlaps the orthographic projection of the first solder mark in a projection plane perpendicular to the first direction.

[0012] By making the orthographic projection of the second seal cover the orthographic projection of the first solder mark, a sealing effect is achieved. At the same time, since the second seal is larger in size, a larger volume first cavity can be formed, which can better balance the internal air pressure of the battery cell.

[0013] In an optional embodiment, the first current collector is welded to the first electrode tab to form a third weld mark; in a projection plane perpendicular to the first direction, the orthographic projection of the third weld mark is misaligned with the orthographic projection of the first weld mark.

[0014] By misaligning the orthographic projection of the third solder mark with that of the first solder mark, damage to the third solder mark can be avoided when the end wall is welded to the first current collector.

[0015] In an optional embodiment, the edge of the second seal is welded to the sidewall to form a fourth weld mark, the fourth weld mark being annular; in a projection plane perpendicular to the first direction, the orthographic projection of the fourth weld mark surrounds the orthographic projection of the first weld mark.

[0016] By arranging the orthographic projection of the fourth weld mark around the orthographic projection of the first weld mark, the orthographic projection of the second seal can cover the orthographic projection of the first weld mark, thus achieving a sealing effect.

[0017] In an optional embodiment, the end wall includes a first region and a second region, the second region being disposed around the first region, the thickness of the first region being greater than the thickness of the second region, and the first region protruding from the second region on the side away from the first current collector, the injection hole penetrating the first region, and the second region being welded to the first current collector to form the first weld mark.

[0018] Because the second region surrounds the first region, and the thickness of the first region is greater than that of the second region, a center-thick and edge-thin end-wall structure can be formed. The thicker first region enhances the structural strength at the injection hole. Simultaneously, because the first region protrudes from the side of the second region away from the first current collector, the possibility of weld slag falling into the injection hole during penetration welding is reduced, thereby minimizing the occurrence of battery cell self-discharge and safety issues caused by weld slag entering the injection hole.

[0019] In an optional embodiment, along the first direction, the thickness of the second region is d1, the thickness of the first current collector is d2, and 75%×d2≤d1≤2×d2.

[0020] By configuring the thickness d1 of the second region to be 75%×d2≤d1≤2×d2, a larger effective weld width can be achieved when welding through the first wall to the current collector.

[0021] In an optional implementation, along the first direction, the thickness of the first region protruding from the second region is h1, where h1 ≥ 0.3 mm.

[0022] By configuring the thickness of the first region protruding from the second region to be not less than 0.3 mm, the possibility of weld slag falling into the injection hole during penetration welding is reduced.

[0023] In an optional embodiment, a crack is formed in a portion of the first solder mark.

[0024] By incorporating cracks, when the internal air pressure of the battery cell is high, the internal airflow can leak through the cracks into the first cavity, reducing the possibility of breakage at other locations of the first solder mark.

[0025] In an optional embodiment, the first current collector is made of aluminum, and the first wall is made of aluminum alloy.

[0026] At this point, the first current collector can act as the positive current collector, and the first wall can act as the positive electrode to conduct current. Furthermore, since the first wall is made of aluminum alloy, it has better strength compared to a pure aluminum structure.

[0027] In an optional embodiment, the first wall is made of aluminum-manganese alloy.

[0028] By selecting aluminum-manganese alloy as the material for the first wall, the first wall can possess the characteristics of aluminum-manganese alloy, thereby improving strength while also having higher formability and good weldability.

[0029] In an optional embodiment, the end wall is through-welded to the first current collector.

[0030] Through penetration welding, the end wall is fixed to the first current collector, and the current is transferred.

[0031] In an optional embodiment, the housing further includes a second wall, which is disposed opposite to the first wall along the first direction, and the second wall is provided with a through hole; the electrode assembly further includes a second tab, which is located at one end of the main body near the second wall; the battery cell further includes a second current collector and a terminal post, the second current collector being disposed between the second wall and the second tab and electrically connected to the second tab, and the terminal post passing through the through hole and welded to the second current collector to form a second solder mark.

[0032] By providing a through hole in the second wall that is opposite to the first wall, and placing the second current collector inside the second wall, the pole post can pass through the through hole to connect with the second current collector.

[0033] In an optional embodiment, the second current collector is welded to the second electrode tab to form a fifth solder mark; in a projection plane perpendicular to the first direction, the orthographic projection of the fifth solder mark is misaligned with the orthographic projection of the second solder mark.

[0034] By misaligning the orthographic projection of the fifth solder mark with that of the second solder mark, damage to the fifth solder mark can be avoided when the electrode post is welded to the second current collector.

[0035] In an optional embodiment, a second groove is provided on the side of the electrode post away from the second current collector, and the second solder mark is exposed on the bottom surface of the second groove; the battery cell further includes a third sealing member, which is welded to the electrode post and covers the opening of the second groove; the third sealing member and the second groove form a second cavity.

[0036] By welding the third seal to the terminal post and covering the opening of the second groove, the second cavity formed between the third seal and the second groove can be sealed, thereby improving the sealing performance of the battery cell.

[0037] In an optional embodiment, the third seal is welded to the pole to form a sixth weld mark, the sixth weld mark being annular; in a projection plane perpendicular to the first direction, the orthographic projection of the sixth weld mark surrounds the orthographic projection of the second weld mark.

[0038] By arranging the orthographic projection of the sixth weld mark around the orthographic projection of the second weld mark, the orthographic projection of the third seal can cover the orthographic projection of the second weld mark, thus achieving a sealing effect.

[0039] In an optional embodiment, the second current collector and the electrode post are made of copper.

[0040] At this point, the second current collector can be used as the negative current collector, and the electrode can be used as the negative electrode to achieve current output.

[0041] In an optional embodiment, the housing includes a shell and an end cap, the shell having a first opening in the first direction, the end cap closing the first opening, and the first wall being the end cap.

[0042] The first wall is configured as an end cap, thereby providing a first protrusion on the end cap.

[0043] In an optional embodiment, the first wall further includes a first connecting portion and a first supporting portion, the first supporting portion being disposed around the outer periphery of the first protrusion, and the first connecting portion being connected between the first supporting portion and the first protrusion; the end wall having a first connecting surface on the side facing the first collector; the first supporting portion having a first supporting surface on the side facing the first collector; the outer shell further includes a second wall, the second wall and the first wall being disposed opposite each other along the first direction; the first connecting surface protruding from the first supporting surface along the direction from the first wall to the second wall.

[0044] When a first support portion is provided around the outer periphery of the first protrusion, the first support portion and the first protrusion can be connected by a first connecting portion. At this time, a first connecting surface is provided on the side of the end wall facing the first current collector, and a first support surface is provided on the side of the first support portion facing the first current collector. By making the first connecting surface protrude from the first support surface in the direction from the first wall to the second wall, the first protrusion can abut against the first current collector before the first support portion when the first wall and the first current collector are assembled, reducing the possibility of assembly gaps between the first protrusion and the first current collector, thereby reducing the occurrence of weld burn-through or incomplete welding problems caused by assembly gaps. At the same time, an assembly space for insulating adhesive can be reserved between the first support portion and the first current collector.

[0045] In an optional embodiment, along the direction from the first wall to the second wall, the first connecting surface protrudes from the first supporting surface by an amount of h2, where h2 ≥ 0.2 mm.

[0046] By making the first connecting surface protrude from the first support surface by a size of not less than 0.2mm in the direction from the first wall to the second wall, the first protrusion can abut against the first current collector before the first support part, reducing the possibility of an assembly gap between the first protrusion and the first current collector. At the same time, assembly space can be reserved for insulating adhesive between the first support part and the first current collector.

[0047] In an optional embodiment, a third groove is provided on the side of the first support portion facing away from the first current collector.

[0048] By providing a third groove, the average thickness of the first support portion can be reduced, thereby reducing the amount of material used in the first wall.

[0049] In an optional embodiment, the first connecting portion has a second connecting surface on the side facing away from the first collector; the first wall further includes a second supporting portion, which is arranged around the outer periphery of the first supporting portion, and the second supporting portion has a second supporting surface on the side facing away from the first collector; the second supporting surface protrudes from the second connecting surface along the direction from the second wall to the first wall.

[0050] When a second support is provided around the outer periphery of the first support, a second connecting surface is provided on the side of the first connecting part facing away from the first current collector, and a second support surface is provided on the side of the second support that faces away from the first current collector. By making the second support surface protrude from the second connecting surface in the direction from the second wall to the first wall, the second support surface can be supported more stably on the battery device housing, reducing the possibility of other positions on the first wall, other than the second support surface, contacting the battery device housing, thereby reducing the problem of poor verticality of the battery cells caused by contact between other positions and the housing.

[0051] In an optional embodiment, along the direction from the second wall to the first wall, the second support surface protrudes from the second connecting surface by a dimension of h3, where h3 ≥ 0.2 mm.

[0052] By making the second support surface protrude from the second connecting surface by a size of not less than 0.2 mm in the direction from the second wall to the first wall, the possibility of other positions on the first wall, other than the second support surface, coming into contact with the battery device housing is reduced.

[0053] In an optional embodiment, the second support portion is provided with a fourth groove on the side facing the first current collector.

[0054] By providing a fourth groove, the average thickness of the second support portion can be reduced, thereby reducing the amount of material used in the first wall.

[0055] In an optional embodiment, the housing includes a shell and an end cap. The shell has a first opening in the first direction, and the end cap closes the first opening. The first wall is the end cap. The first wall also includes a second connecting portion, which surrounds the outer periphery of the second support portion and is connected to the shell. A second gap is formed between the second connecting portion and the first current collector along the first direction. The battery cell also includes insulating tape, which at least partially covers the first tab and is located in the second gap.

[0056] By providing a second connecting part around the outer periphery of the second support, the connection between the first wall and the housing is achieved. At the same time, by forming a second gap between the second connecting part and the first current collector, assembly space can be reserved between the second connecting part and the first current collector for insulating adhesive.

[0057] In an optional embodiment, the electrode assembly is a wound structure, and the battery cell is a cylindrical battery cell.

[0058] By configuring the electrode assembly as a wound structure, it can be placed inside the casing of a cylindrical battery cell.

[0059] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.

[0060] The battery device provided according to this application includes the battery cell described in any one of the first aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0061] Thirdly, this application provides an electrical device that includes the battery device described in the above embodiments.

[0062] The electrical equipment provided according to this application includes the battery device described in any one of the first aspect embodiments, and therefore has the technical effects described in any of the above embodiments, which will not be repeated here.

[0063] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0064] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0065] Figure 1 This is a schematic diagram of the vehicle structure in some embodiments of this application;

[0066] Figure 2 This is an exploded view of the battery device in some embodiments of this application;

[0067] Figure 3 This is a schematic diagram of the structure of a single battery cell in some embodiments of this application;

[0068] Figure 4 This is a cross-sectional schematic diagram of a battery cell in some embodiments of this application;

[0069] Figure 5 for Figure 4 Enlarged view of point A in the middle;

[0070] Figure 6 for Figure 4 Enlarged view of point B in the middle;

[0071] Figure 7 for Figure 4 Enlarged view of point C in the middle;

[0072] Figure 8 This is a cross-sectional schematic diagram of the first wall of a battery cell in some embodiments of this application.

[0073] The reference numerals in the detailed embodiments are as follows:

[0074] 1000, vehicles;

[0075] 100. Battery assembly; 200. Controller; 300. Motor;

[0076] 10. Box body; 11. First part; 12. Second part;

[0077] 20. Battery cell; 21. Casing; 211. End cap; 212. Housing; 22. Electrode assembly; 221. Main body; 222. First tab; 223. Second tab; 23. Terminal post; 231. Second groove; 232. Second solder mark; 24. First current collector; 25. First seal; 26. Second seal; 261. Stress relief groove; 27. Second current collector; 28. Third seal; 29. ​​Insulating tape; 20a. Third solder mark; 20b. Fourth solder mark; 20c. Fifth solder mark; 20d. Sixth solder mark; 201. First cavity;

[0078] S10, First wall; S1, First protrusion; S11, End wall; S111, First region; S112, Second region; S113, First connecting surface; S12, Side wall; S121, Step surface; S13, First groove; S14, Injection hole; S15, First weld mark; S151, Crack; S2, First connecting part; S21, Second connecting surface; S3, First support part; S31, First support surface; S32, Third groove; S4, Second support part; S41, Second support surface; S42, Fourth groove; S5, Second connecting part;

[0079] S20, Second wall; S201, Through hole;

[0080] z, First direction. Detailed Implementation

[0081] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0082] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0083] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0084] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0085] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0086] Currently, judging from market trends, the application of power battery devices is becoming increasingly widespread. Power battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields. With the continuous expansion of the application areas of power battery devices, the market demand is also constantly increasing.

[0087] Currently, commonly used cylindrical battery cells generally adopt a full tab structure. After the electrode assembly is wound, the tabs at both ends of the electrode assembly are flattened to compress the tabs axially, resulting in a denser and flatter tab end face. Then, the shaped tab end face is connected to the current collector by welding to achieve the purpose of current carrying.

[0088] The existing cylindrical battery cells are generally made of aluminum or steel.

[0089] When the outer casing is made of aluminum, the current collector of the battery cell generally adopts a "Z"-shaped bending structure. When welding the current collector to the tab and the outer casing (or terminal post), the current collector needs to be unfolded first. After welding is completed, the current collector is folded and housed in the outer casing. The current collector requires a large housing space, which will affect the energy density of the battery cell.

[0090] To address this, and to improve assembly efficiency and the energy density of individual battery cells, a non-foldable current collector can be used to replace the existing foldable current collector. This involves first press-fitting the non-foldable current collector to the end cap, and then using laser external penetration welding to extract the current. However, to ensure the strength of the casing, the aluminum used is generally an aluminum alloy (such as 3-series aluminum alloy) rather than 1-series pure aluminum. This makes it easy for cracks to form at the weld termination of the penetration weld, leading to a risk of leakage from the individual battery cells.

[0091] To reduce the risk of leakage at the weld termination point of the battery cell in the penetration weld, research has found that a sealing pin that can be welded to the end cap can be set on the outside of the weld. A cavity structure can be formed between the sealing pin and the end cap to receive the internal gas of the battery cell from the crack. The sealing pin can achieve sealing at the crack, and the cavity structure can balance the internal gas pressure of the battery cell, thereby improving the sealing effect of the battery cell and thus improving the performance and service life of the power battery device.

[0092] Based on the above considerations, to address the issue of cracks easily forming at the weld termination of the through-weld in battery cells, leading to leakage risks, a new battery cell design is proposed. A first protrusion, consisting of an end wall and a side wall, is formed on the first wall. Firstly, an injection hole is formed on the end wall, and a first sealing element blocks the injection hole, achieving sealing. Secondly, the welding position between the first wall and the first current collector is located on the end wall. Thus, both the first weld mark and the injection hole are located on the end wall. At this point, welding a second sealing element to the side wall further seals the injection hole and also seals the first cavity formed by the second sealing element, the side wall, and the end wall. This allows gas leaking from the first weld mark when the internal pressure of the battery cell is high to be contained within the first cavity, balancing the internal pressure of the battery cell. This battery cell, by simultaneously placing the injection hole and the first weld mark on the end wall and improving the sealing effect through the second sealing element, can thereby enhance the performance and lifespan of the power battery device.

[0093] The battery device disclosed in this application can be used, but is not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power system for such electrical equipment can be constructed using the battery device disclosed in this application.

[0094] The technical solutions described in this application are applicable to various battery-powered devices, such as mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0095] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0096] Please refer to Figure 1 , Figure 1This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000, or it can be used in the vehicle 1000's electrical system, such as to meet the power requirements for starting, navigation, and operation of the vehicle 1000.

[0097] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0098] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0099] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, with the battery cells 20 housed within the housing 10. The housing 10 provides space for the battery cells 20, and the housing 10 can employ various structures.

[0100] In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, and together define a receiving space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, with the first portion 11 covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 together define the receiving space; alternatively, the first portion 11 and the second portion 12 may both be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0101] In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form battery device modules, and then these modules are connected in series, parallel, or in a mixed manner to form a whole, which is then housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0102] Each battery cell 20 can be a secondary battery device, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0103] Reference Figures 3 to 4 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. Figure 4 This is a cross-sectional schematic diagram of a battery cell 20 in some embodiments of this application. A battery cell 20 refers to the smallest unit constituting the battery device 100. For example... Figure 3 and Figure 4 The battery cell 20 includes a casing 21, an electrode assembly 22, and other functional components.

[0104] The outer casing 21 includes an end cap 211 and a housing 212. The end cap 211 is a component that covers the opening of the housing 212 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 211 can be adapted to the shape of the housing 212 to fit it. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 211 is less prone to deformation under pressure and impact, allowing the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as terminals 23 can be provided on the end cap 211. The terminals 23 can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the end cap 211 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 211. The insulating member can be used to isolate the electrical connection components in the housing 212 from the end cap 211 to reduce the risk of short circuit. For example, the insulating member can be plastic, rubber, etc.

[0105] The housing 212 is a component used to cooperate with the end cap 211 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 212 and the end cap 211 can be independent components. An opening can be provided on the housing 212, and the end cap 211 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 211 and the housing 212 can be integrated. Specifically, the end cap 211 and the housing 212 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 212, the end cap 211 closes the housing 212. The housing 212 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 212 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 212 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0106] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 212 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the terminals to form a current loop.

[0107] According to some embodiments of this application, reference is made to Figure 3 and Figure 4 and refer to Figures 5 to 8 , Figure 5 for Figure 4 Enlarged diagram of point A in the middle. Figure 6 for Figure 4 Enlarged diagram at point B in the middle. Figure 7 for Figure 4 Enlarged diagram of point C in the middle. Figure 8 This is a cross-sectional schematic diagram of the first wall S10 of the battery cell 20 in some embodiments of this application.

[0108] This application provides a battery device 100, including a housing 21, an electrode assembly 22, and a first current collector 24. The housing 21 has a first wall S10 in a first direction z. The electrode assembly 22 is disposed within the housing 21 and includes a main body 221 and a first tab 222. The first tab 222 is located at the end of the main body 221 near the first wall S10. The first current collector 24 is disposed between the first wall S10 and the first tab 222 and is electrically connected to the first tab 222.

[0109] The first wall S10 protrudes partially toward the first current collector 24 to form a first protrusion S1. The first protrusion S1 includes an end wall S11 and a side wall S12 disposed around the end wall S11. The side wall S12 and the end wall S11 form a first groove S13. The end wall S11 is welded to the first current collector 24 to form a first weld mark S15. The end wall S11 is provided with an injection hole S14.

[0110] The battery cell 20 also includes a first seal 25 and a second seal 26. The first seal 25 blocks the liquid injection hole S14. The second seal 26 is at least partially housed in the first groove S13. The edge of the second seal 26 is welded to the side wall S12. The second seal 26, the side wall S12 and the end wall S11 form a first cavity 201.

[0111] The first seal 25 can be selected as a rubber nail.

[0112] The second seal 26 can be selected as a sealing pin made of the same material as the first wall S10.

[0113] In the technical solution of this application embodiment, a first protrusion S1 is formed in the first wall S10, which is composed of an end wall S11 and a side wall S12. On the one hand, by forming an injection hole S14 in the end wall S11 and sealing the injection hole S14 with the first sealing member 25, the injection hole S14 is sealed. On the other hand, the welding position of the first wall S10 and the first current collector 24 is set in the end wall S11. Thus, the first weld mark S15 and the injection hole S14 are both located in the end wall S11. At this time, by welding the second sealing member 26 to the side wall S12, the injection hole S14 can be further sealed, and the first cavity 201 formed between the second sealing member 26, the side wall S12 and the end wall S11 can also be sealed. This allows the gas leaking from the first weld mark S15 when the internal gas pressure of the battery cell 20 is high to be contained in the first cavity 201, thereby balancing the internal gas pressure of the battery cell 20. The battery cell 20 has the liquid injection hole S14 and the first solder mark S15 simultaneously located on the end wall S11. The sealing effect of the battery cell 20 can be improved by the setting of the second sealing member 26, thereby improving the performance and service life of the battery device 100.

[0114] According to some embodiments of this application, refer to Figure 5A crack S151 is formed in a localized area of ​​the first solder mark S15.

[0115] Crack S151 may form at the end of the first solder mark S15.

[0116] By setting the crack S151, when the internal air pressure of the battery cell 20 is high, the internal airflow can leak from the crack S151 into the first cavity 201, reducing the possibility of breakage at other locations of the first solder mark S15.

[0117] According to some embodiments of this application, refer to Figure 4 and Figure 6 The first current collector 24 and the first electrode 222 are connected by welding to achieve electrical connection between the first current collector 24 and the first electrode 222.

[0118] Furthermore, when the first current collector 24 is welded to the first electrode tab 222, a third weld mark 20a will be formed. In the projection plane perpendicular to the first direction z, the orthographic projection of the third weld mark 20a can be misaligned with the orthographic projection of the first weld mark S15 to avoid damage to the third weld mark 20a when the end wall S11 is welded to the first current collector 24.

[0119] According to some embodiments of this application, refer to Figures 4-6 The edge of the second seal 26 is welded to the side wall S12 to form a fourth weld mark 20b, which is annular. In a projection plane perpendicular to the first direction z, the orthographic projection of the fourth weld mark 20b surrounds the orthographic projection of the first weld mark S15.

[0120] By arranging the orthographic projection of the fourth solder mark 20b around the orthographic projection of the first solder mark S15, the orthographic projection of the second seal 26 can cover the orthographic projection of the first solder mark S15, thereby achieving a sealing effect.

[0121] According to some embodiments of this application, refer to Figures 4-8 The second seal 26 is provided with a stress relief groove 261, which is arranged in a ring shape along the edge of the second seal 26.

[0122] When the second seal 26 is welded to the side wall S12, the weld edge of the second seal 26 is easily stretched due to the welding. By setting an annular stress relief groove 261 on the edge of the second seal 26, the second seal 26 can be stretched at the stress relief groove 261 to release the stress generated by welding.

[0123] According to some embodiments of this application, refer to Figures 4-8 The inner circumferential surface of the side wall S12 is provided with a stepped surface S121, and the second sealing member 26 abuts against the stepped surface S121 along the first direction z.

[0124] By providing a stepped surface S121 on the inner circumferential surface of the side wall S12, and enabling the second sealing member 26 to abut against the stepped surface S121 along the first direction z, the second sealing member 26 can be lapped and positioned before welding through the stepped surface S121, so as to facilitate subsequent welding.

[0125] According to some embodiments of this application, refer to Figures 4-8 The thickness h4 of the sidewall S12 is not less than 1.2 mm.

[0126] By setting the thickness h4 of the sidewall S12 to not less than 1.2 mm, the sidewall S12 is prevented from being welded through during the welding of the second seal 26. If the sidewall S12 is welded through or the laser leaks into the interior of the battery cell 20, the laser will be reflected and burn the battery cell 20.

[0127] According to some embodiments of this application, refer to Figures 4-8 In the projection plane perpendicular to the first direction z, the orthographic projection of the second seal 26 covers the orthographic projection of the first solder mark S15.

[0128] By making the orthographic projection of the second seal 26 cover the orthographic projection of the first solder mark S15, a sealing effect is achieved. At the same time, since the second seal 26 is larger in size, a larger volume first cavity 201 can be formed, which can better balance the internal air pressure of the battery cell 20.

[0129] According to some embodiments of this application, refer to Figures 4-8 The end wall S11 includes a first region S111 and a second region S112. The second region S112 is arranged around the first region S111. The thickness of the first region S111 is greater than the thickness of the second region S112. The first region S111 protrudes from the side of the second region S112 away from the first collector 24. The injection hole S14 penetrates the first region S111. The second region S112 is welded to the first collector 24 to form a first weld mark S15.

[0130] Since the second region S112 surrounds the first region S111, and the thickness of the first region S111 is greater than the thickness of the second region S112, a center-thick and edge-thin endwall S11 structure can be formed. The thicker first region S111 enhances the structural strength at the injection hole S14. Simultaneously, since the first region S111 protrudes from the side of the second region S112 away from the first current collector 24, the possibility of weld slag falling into the injection hole S14 during penetration welding can be reduced, thereby reducing the occurrence of self-discharge and safety issues in the battery cell 20 caused by weld slag falling into the injection hole S14.

[0131] According to some embodiments of this application, refer to Figures 4-8Along the first direction z, the thickness of the second region S112 is d1, and the thickness of the first current collector 24 is d2, where 75%×d2≤d1≤2×d2. Optionally, d2=d1.

[0132] The thickness of the second region S112 can be changed by local thinning.

[0133] By configuring the thickness d1 of the second region S112 to 75%×d2≤d1≤2×d2, a larger effective weld width can be achieved when welding through the first wall S10 to the first current collector 24.

[0134] According to some embodiments of this application, refer to Figures 4-8 Along the first direction z, the thickness h1 of the first region S111 protruding from the second region S112 is not less than 0.3mm.

[0135] By configuring the thickness h1 of the first region S111 protruding from the second region S112 to be not less than 0.3 mm, the possibility of weld slag falling into the injection hole S14 during penetration welding is reduced.

[0136] According to some embodiments of this application, refer to Figures 4-8 The first current collector 24 is made of aluminum, and the first wall S10 is made of aluminum alloy.

[0137] At this time, the first current collector 24 can be used as the positive current collector, and the first wall S10 can be used as the positive electrode to realize current conduction. Since the first wall S10 is made of aluminum alloy, it has better strength than a pure aluminum structure.

[0138] According to some embodiments of this application, refer to Figures 4-8 The first wall S10 is made of aluminum-manganese alloy.

[0139] Aluminum-manganese alloy (Al-Mn) is a rust-resistant aluminum alloy with manganese as the main alloying element. The manganese content is usually between 1.0% and 1.5%. It has higher strength than 1-series aluminum (formed by adding a small amount of copper to pure aluminum) and has good formability, weldability, thermal conductivity and corrosion resistance.

[0140] By selecting 3-series aluminum alloy as the material for the first wall S10, the first wall S10 can have the characteristics of 3-series aluminum alloy, which improves strength while also having higher formability and good weldability.

[0141] According to some embodiments of this application, refer to Figures 4-8 The end wall S11 is welded through to the first current collector 24.

[0142] Penetration welding utilizes the high temperature and energy of an electric arc to melt and weld metals. It typically requires an inert gas shield to prevent impurities such as oxygen and moisture from affecting the weld. Penetration welding is a simple and low-cost process.

[0143] Through penetration welding, the fixation between the end wall S11 and the first current collector 24 and the current transfer are achieved.

[0144] According to some embodiments of this application, refer to Figures 4-8 The outer casing 21 also includes a second wall S20, which is disposed opposite to the first wall S10 along the first direction z, and the second wall S20 is provided with a through hole S201.

[0145] The electrode assembly 22 also includes a second tab 223, which is located at one end of the main body 221 near the second wall S20.

[0146] The battery cell 20 also includes a second current collector 27 and a terminal post 23. The second current collector 27 is disposed between the second wall S20 and the second tab 223 and is electrically connected to the second tab 223. The terminal post 23 passes through the through hole S201 and is welded to the second current collector 27 to form a second solder mark 232.

[0147] By providing a through hole S201 at the second wall S20 which is opposite to the first wall S10, and placing the second current collector 27 inside the second wall S20, the pole post 23 can pass through the through hole S201 to connect with the second current collector 27.

[0148] According to some embodiments of this application, refer to Figure 4 and Figure 7 The second current collector 27 is welded to the second electrode tab 223 to form a fifth weld mark 20c. In the projection plane perpendicular to the first direction z, the orthographic projection of the fifth weld mark 20c is offset from the orthographic projection of the second weld mark 232.

[0149] By misaligning the orthographic projection of the fifth solder mark 20c with the orthographic projection of the second solder mark 232, damage to the fifth solder mark 20c can be avoided when the pole post 23 is welded to the second current collector 27.

[0150] According to some embodiments of this application, refer to Figures 4-8 The pole post 23 has a second groove 231 on the side away from the second current collector 27, and the second solder mark 232 is exposed on the bottom surface of the second groove 231.

[0151] The battery cell 20 also includes a third seal 28, which is welded to the terminal post 23 and covers the opening of the second groove 231.

[0152] The third seal 28 and the second groove 231 form a second cavity.

[0153] The third seal 28 can be selected as a sealing pin made of the same material as the pole post 23.

[0154] By welding the third seal 28 to the pole post 23 and covering the opening of the second groove 231, the second cavity formed between the third seal 28 and the second groove 231 can be sealed, thereby improving the sealing performance of the battery cell 20.

[0155] According to some embodiments of this application, refer to Figure 4 and Figure 7 The third seal 28 is welded to the pole post to form a sixth weld mark 20d, which is annular. In the projection plane perpendicular to the first direction z, the orthographic projection of the sixth weld mark 20d surrounds the orthographic projection of the second weld mark 232.

[0156] By arranging the orthographic projection of the sixth weld mark 20d around the orthographic projection of the second weld mark 232, the orthographic projection of the third seal 28 can cover the orthographic projection of the second weld mark 232, thus achieving a sealing effect.

[0157] According to some embodiments of this application, refer to Figures 4-8 The second current collector 27 and the pole post 23 are made of copper.

[0158] At this time, the second current collector 27 can be used as the negative current collector, and the electrode 23 can be used as the negative electrode to realize current output.

[0159] According to some embodiments of this application, refer to Figures 4-8 The outer casing 21 includes a housing 212 and an end cap 211. The housing 212 has a first opening in the first direction z, and the end cap 211 closes the first opening. The first wall S10 is the end cap 211.

[0160] The first wall S10 is configured as an end cap 211, so that a first protrusion S1 can be provided on the end cap 211.

[0161] According to some embodiments of this application, refer to Figures 4-8 The first wall S10 also includes a first connecting portion S2 and a first supporting portion S3. The first supporting portion S3 is disposed around the outer periphery of the first protrusion S1, and the first connecting portion S2 connects the first supporting portion S3 and the first protrusion S1. The end wall S11 is provided with a first connecting surface S113 on the side facing the first current collector 24.

[0162] The first support part S3 has a first support surface S31 on the side facing the first current collector 24.

[0163] The outer casing 21 also includes a second wall S20, which is disposed opposite to the first wall S10 along the first direction z.

[0164] Along the direction from the first wall S10 to the second wall S20, the first connecting surface S113 protrudes from the first supporting surface S31.

[0165] When the first support portion S3 is provided around the outer periphery of the first protrusion S1, the first support portion S3 and the first protrusion S1 can be connected by the first connecting portion S2. At this time, the first connecting surface S113 is provided on the side of the end wall S11 facing the first current collector 24, and the first support surface S31 is provided on the side of the first support portion S3 facing the first current collector 24. By making the first connecting surface S113 protrude from the first support surface S31 in the direction from the first wall S10 to the second wall S20, the first protrusion S1 can abut against the first current collector 24 before the first support portion S3 when the first wall S10 is assembled with the first current collector 24, thereby reducing the possibility of assembly gap between the first protrusion S1 and the first current collector 24, and thus reducing the occurrence of weld penetration or incomplete welding caused by assembly gap. At the same time, an assembly space for insulating glue can be reserved between the first support portion S3 and the first current collector 24.

[0166] According to some embodiments of this application, refer to Figures 4-8 Along the direction from the first wall S10 to the second wall S20, the first connecting surface S113 protrudes from the first supporting surface S31 by a dimension h2 of not less than 0.2mm, such as 0.25mm, 0.4mm, 0.6mm, etc.

[0167] By making the first connecting surface S113 protrude from the first support surface S31 by a size h2 of not less than 0.2mm in the direction from the first wall S10 to the second wall S20, the first protrusion S1 can abut against the first current collector 24 before the first support S3, reducing the possibility of an assembly gap between the first protrusion S1 and the first current collector 24. At the same time, assembly space can be reserved for insulating adhesive between the first support S3 and the first current collector 24.

[0168] According to some embodiments of this application, refer to Figures 4-8 A third groove S32 is provided on the side of the first support part S3 facing away from the first current collector 24.

[0169] By setting the third groove S32, the average thickness of the first support S3 can be reduced, thereby reducing the material used in the first wall S10.

[0170] According to some embodiments of this application, refer to Figures 4-8 The first connecting part S2 has a second connecting surface S21 on the side opposite to the first current collector 24.

[0171] The first wall S10 also includes a second support portion S4, which is arranged around the outer periphery of the first support portion S3. A second support surface S41 is provided on the side of the second support portion S4 facing away from the first current collector 24.

[0172] Along the direction from the second wall S20 to the first wall S10, the second support surface S41 protrudes from the second connecting surface S21.

[0173] When the second support S4 is arranged around the outer periphery of the first support S3, a second connecting surface S21 is provided on the side of the first connecting part S2 facing away from the first current collector 24, and a second support surface S41 is provided on the side of the second support S4 facing away from the first current collector 24. By making the second support surface S41 protrude from the second connecting surface S21 in the direction from the second wall S20 to the first wall S10, the second support surface S41 can be supported more stably on the housing 10 of the battery device 100, reducing the possibility of other positions on the first wall S10 (such as the first connecting part S2, the second seal 26, and the weld between the second seal 26 and the side wall S12) coming into contact with the housing 10 of the battery device 100, thereby reducing the occurrence of the problem of poor verticality of the battery cells caused by other positions coming into contact with the housing 10.

[0174] According to some embodiments of this application, refer to Figures 4-8 To reduce the possibility of the second seal 26 coming into contact with the housing 10, the second support surface S41 protrudes from the second seal 26 in the direction from the second wall S20 to the first wall S10.

[0175] To reduce the possibility of the weld between the second seal 26 and the side wall S12 coming into contact with the housing 10, the second support surface S41 protrudes from the weld between the second seal 26 and the side wall S12 in the direction from the second wall S20 to the first wall S10.

[0176] According to some embodiments of this application, refer to Figures 4-8 Along the direction from the second wall S20 to the first wall S10, the second support surface S41 protrudes from the second connecting surface S21 by a dimension h3 of not less than 0.2mm, such as 0.25mm, 0.4mm, 0.6mm, etc.

[0177] By making the second support surface S41 protrude by a dimension h3 of not less than 0.2 mm from the second connecting surface S21 in the direction from the second wall S20 to the first wall S10, the possibility of other positions on the first wall S10 other than the second support surface S41 coming into contact with the housing 10 of the battery device 100 is reduced.

[0178] According to some embodiments of this application, refer to Figures 4-8 The second support S4 has a fourth groove S42 on the side facing the first current collector 24.

[0179] By providing the fourth groove S42, the average thickness of the second support S4 can be reduced, thereby reducing the material used in the first wall S10.

[0180] According to some embodiments of this application, refer to Figures 4-8 The outer casing 21 includes a housing 212 and an end cap 211. The housing 212 has a first opening in the first direction z, and the end cap 211 closes the first opening. The first wall S10 is the end cap 211.

[0181] The first wall S10 also includes a second connecting part S5, which is arranged around the outer periphery of the second support part S4 and is connected to the housing 212.

[0182] Along the first direction z, a second gap is formed between the second connecting part S5 and the first current collector 24.

[0183] The battery cell 20 also includes insulating tape 29, which at least partially covers the first tab 222 and at least part of the insulating tape 29 is located in the second gap.

[0184] By providing a second connecting part S5 around the outer periphery of the second support part S4, the connection between the first wall S10 and the housing 212 is realized. At the same time, by forming a second gap between the second connecting part S5 and the first current collector 24, assembly space can be reserved for insulating adhesive between the second connecting part S5 and the first current collector 24.

[0185] According to some embodiments of this application, refer to Figures 4-8 The electrode assembly 22 has a wound structure, and the battery cell 20 is a cylindrical battery cell 20.

[0186] The electrode assembly 22 is configured as a wound structure so that it can be placed inside the housing 21 of the cylindrical battery cell 20.

[0187] According to some embodiments of this application, the tabs of the battery cell 20 are all tabs.

[0188] According to some embodiments of this application, this application also provides a battery device 100, including a battery cell 20 of any of the above schemes.

[0189] According to some embodiments of this application, this application also provides an electrical device including a battery device 100 of any of the above schemes, the battery device 100 being used to provide electrical energy to the electrical device.

[0190] The electrical equipment can be any of the aforementioned devices or systems that utilize battery devices 100.

[0191] According to some embodiments of this application, see Figure 2 , Figures 4-8This application provides a battery device 100, whose housing 10 includes a plurality of battery cells 20, which are arranged in multiple rows and columns.

[0192] The battery cell 20 includes a housing 21, an electrode assembly 22, a terminal post 23, a first current collector 24, a second current collector 27, a first seal 25, a second seal 26, and a third seal 28. The housing 21 includes a first wall S10 and a second wall S20 disposed opposite to each other along a first direction z.

[0193] The first wall S10 includes a first protrusion S1, a first connecting part S2, a first supporting part S3, a second supporting part S4, and a second connecting part S5 connected in sequence.

[0194] The first protrusion S1 includes an end wall S11 and a side wall S12 disposed around the end wall S11. The side wall S12 and the end wall S11 form a first groove S13. The end wall S11 includes a first region S111 and a second region S112 disposed around the first region S111. The injection hole S14 is disposed through the first region S111. The second region S112 is welded to the first current collector 24 to form a first weld mark S15.

[0195] The first seal 25 blocks the injection hole S14, and the second seal 26 is at least partially housed within the first groove S13. The edge of the second seal 26 is welded to the side wall S12, and the second seal 26, the side wall S12, and the end wall S11 form a first cavity 201. A stress relief groove 261 is provided on the second seal 26, and the stress relief groove 261 is arranged in a ring shape along the edge of the second seal 26.

[0196] Along the direction from the first wall S10 to the second wall S20, the end wall S11 protrudes from the first connecting surface S113 of the first current collector 24, which is opposite to the first support surface S31 of the first support part S3 facing the first support surface S31 of the first current collector 24.

[0197] Along the direction from the second wall S20 to the first wall S10, the second support surface S41 of the second support part S4, which faces away from the first collector 24, protrudes from the second connecting surface S21 of the first connecting part S2, which faces away from the first collector 24.

[0198] The electrode assembly 22 includes a main body 221, a first electrode tab 222 and a second electrode tab 223. The first electrode tab 222 is located at the end of the main body 221 near the first wall S10, and the second electrode tab 223 is located at the end of the main body 221 near the second wall S20.

[0199] The second current collector 27 is disposed between the second wall S20 and the second electrode 223 and is electrically connected to the second electrode 223. The electrode post 23 passes through the through hole S201. A second groove 231 is provided on the side of the electrode post 23 away from the second current collector 27. The bottom surface of the groove 231 is welded to the second current collector 27 to form a second weld mark exposed in the second groove 231. The third sealing member 28 is welded to the electrode post 23 and covers the opening of the second groove 231.

[0200] The assembly process of the battery cell 20 provided in this application is as follows:

[0201] (1) The positive electrode, negative electrode and separator are wound together to form a bare cell (i.e., electrode assembly).

[0202] (2) Weld the first tab 222 (i.e., the positive tab) of the bare cell to the first current collector 24, and weld the second tab 223 (i.e., the negative tab) to the second current collector 27;

[0203] (3) After welding the first current collector 24 and the second current collector 27, perform tab insulation treatment on the bare battery cell: wrap the positive and negative electrodes with insulating tape 29 respectively. The end face of the insulating tape 29 on the positive electrode side extends 3mm~8mm beyond the outer end face of the first current collector 24. The insulating tape 29 extending beyond the outer end face of the first current collector 24 is smoothed towards the first current collector 24 to adhere to the outer end face of the first current collector 24. The end face of the insulating tape 29 on the negative electrode side extends 3mm~8mm beyond the outer end face of the second current collector 27. The insulating tape 29 extending beyond the outer end face of the second current collector 27 is smoothed towards the second current collector 27 to adhere to the outer end face of the second current collector 27.

[0204] (4) Insert the bare battery cell with insulation completed into the casing;

[0205] (5) Close the end cap 211 to the housing 212 and complete the laser welding seal;

[0206] (6) The end cap 211 is welded to the first current collector 24 by laser penetration welding;

[0207] (7) The penetration electrode 23 is welded to the second current collector 27;

[0208] (8) Weld the third seal 28 to the pole post 23;

[0209] (9) Testing procedures such as liquid injection;

[0210] (10) Install the first seal 25 into the injection hole S14;

[0211] (11) Weld the second seal 26 to the side wall S12 of the first protrusion S1.

[0212] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This 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, include: A housing having a first wall in a first direction; An electrode assembly is disposed within the housing. The electrode assembly includes a main body and a first electrode tab, wherein the first electrode tab is located at one end of the main body near the first wall. The first current collector is disposed between the first wall and the first electrode tab, and is electrically connected to the first electrode tab; Wherein, a portion of the first wall protrudes toward the first current collector to form a first protrusion, the first protrusion includes an end wall and a side wall disposed around the end wall, the side wall and the end wall form a first groove, the end wall is welded to the first current collector to form a first weld mark, and the end wall is provided with a liquid injection hole; The battery cell further includes a first seal and a second seal. The first seal blocks the liquid injection hole, and the second seal is at least partially housed in the first groove. The edge of the second seal is welded to the side wall, and the second seal, the side wall, and the end wall form a first cavity.

2. The battery cell according to claim 1, characterized in that, The second seal is provided with a stress relief groove, which is arranged in a ring shape along the edge of the second seal.

3. The battery cell according to claim 1, characterized in that, The inner circumferential surface of the sidewall is provided with a stepped surface, and the second sealing member abuts against the stepped surface along the first direction.

4. The battery cell according to claim 1, characterized in that, In a projection plane perpendicular to the first direction, the orthographic projection of the second seal overlaps the orthographic projection of the first solder mark.

5. The battery cell according to claim 1, characterized in that, The first current collector is welded to the first electrode tab to form a third solder mark; In a projection plane perpendicular to the first direction, the orthographic projection of the third solder mark is misaligned with the orthographic projection of the first solder mark.

6. The battery cell according to claim 1, characterized in that, The edge of the second seal is welded to the sidewall to form a fourth weld mark, which is annular. In a projection plane perpendicular to the first direction, the orthographic projection of the fourth solder mark is arranged around the orthographic projection of the first solder mark.

7. The battery cell according to claim 1, characterized in that, The end wall includes a first region and a second region, the second region is disposed around the first region, the thickness of the first region is greater than the thickness of the second region, and the first region protrudes from the second region on the side away from the first current collector, the injection hole penetrates through the first region, and the second region is welded to the first current collector to form the first weld mark.

8. The battery cell according to claim 7, characterized in that, Along the first direction, the thickness of the second region is d1, the thickness of the first current collector is d2, and 75%×d2≤d1≤2×d2.

9. The battery cell according to claim 7, characterized in that, Along the first direction, the thickness of the first region protruding from the second region is h1, where h1 ≥ 0.3 mm.

10. The battery cell according to claim 1, characterized in that, The first solder mark has a localized crack.

11. The battery cell according to claim 1, characterized in that, The first current collector is made of aluminum, and the first wall is made of aluminum alloy.

12. The battery cell according to claim 11, characterized in that, The first wall is made of aluminum-manganese alloy.

13. The battery cell according to claim 1, characterized in that, The end wall is welded through to the first current collector.

14. The battery cell according to claim 1, characterized in that, The outer casing also includes a second wall, which is disposed opposite to the first wall along the first direction, and the second wall is provided with a through hole; The electrode assembly further includes a second electrode tab, which is located at one end of the main body near the second wall; The battery cell also includes a second current collector and a terminal post. The second current collector is disposed between the second wall and the second tab and is electrically connected to the second tab. The terminal post passes through the through hole and is welded to the second current collector to form a second weld mark.

15. The battery cell according to claim 14, characterized in that, The second current collector is welded to the second electrode tab to form a fifth solder mark; In a projection plane perpendicular to the first direction, the orthographic projection of the fifth solder mark is misaligned with the orthographic projection of the second solder mark.

16. The battery cell according to claim 14, characterized in that, The pole post is provided with a second groove on the side away from the second current collector, and the second solder mark is exposed on the bottom surface of the second groove. The battery cell also includes a third sealing element, which is welded to the terminal post and covers the opening of the second groove; The third seal and the second groove form a second cavity.

17. The battery cell according to claim 16, characterized in that, The third sealing element is welded to the pole post to form a sixth weld mark, which is ring-shaped; In a projection plane perpendicular to the first direction, the orthographic projection of the sixth solder mark is arranged around the orthographic projection of the second solder mark.

18. The battery cell according to claim 14, characterized in that, The second current collector and the electrode post are made of copper.

19. The battery cell according to claim 1, characterized in that, The outer casing includes a housing and an end cap. The housing has a first opening in the first direction, and the end cap closes the first opening. The first wall is the end cap.

20. The battery cell according to any one of claims 1-19, characterized in that, The first wall further includes a first connecting portion and a first supporting portion. The first supporting portion is disposed around the outer periphery of the first protrusion, and the first connecting portion is connected between the first supporting portion and the first protrusion. The end wall is provided with a first connecting surface on the side facing the first current collector. The first support portion has a first support surface on the side facing the first current collector; The outer casing further includes a second wall, which is disposed opposite to the first wall along the first direction; Along the direction from the first wall to the second wall, the first connecting surface protrudes from the first supporting surface.

21. The battery cell according to claim 20, characterized in that, Along the direction from the first wall to the second wall, the first connecting surface protrudes from the first supporting surface by an amount of h2, where h2 ≥ 0.2 mm.

22. The battery cell according to claim 20, characterized in that, A third groove is provided on the side of the first support portion facing away from the first current collector.

23. The battery cell according to claim 20, characterized in that, A second connecting surface is provided on the side of the first connecting portion facing away from the first current collector; The first wall also includes a second support portion, which is arranged around the outer periphery of the first support portion, and a second support surface is provided on the side of the second support portion facing away from the first collector. Along the direction from the second wall to the first wall, the second support surface protrudes from the second connecting surface.

24. The battery cell according to claim 23, characterized in that, Along the direction from the second wall to the first wall, the second support surface protrudes from the second connecting surface by a dimension of h3, where h3 ≥ 0.2 mm.

25. The battery cell according to claim 23, characterized in that, The second support portion has a fourth groove on the side facing the first current collector.

26. The battery cell according to claim 23, characterized in that, The outer casing includes a housing and an end cap, the housing having a first opening in the first direction, the end cap closing the first opening, and the first wall being the end cap; The first wall also includes a second connecting portion, which is disposed around the outer periphery of the second support portion and is connected to the housing; Along the first direction, a second gap is formed between the second connecting portion and the first current collector; The battery cell also includes insulating tape, which at least partially covers the first tab and at least a portion of the insulating tape is located in the second gap.

27. The battery cell according to claim 1, characterized in that, The electrode assembly has a wound structure, and the battery cell is a cylindrical battery cell.

28. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-27.

29. An electrical appliance, characterized in that, Includes the battery device as described in claim 28.

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