Battery monomer, battery device and electric equipment

Abstract

The utility model relates to a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell, the shell comprises a plurality of outer walls, a containing cavity is defined by the plurality of outer walls, at least one outer wall is provided with a mounting hole communicated with the containing cavity, and the part, surrounding the mounting hole, of the outer wall is bent towards the containing cavity to form a step part; the pressure relief mechanism comprises a main body part and a lap joint part connected to the circumferential edge of the main body part, the main body part is arranged in the mounting hole in a penetrating mode, and the lap joint part is connected with the side, away from the containing cavity, of the step part in a welded mode; the thickness h1 of the lap joint part and the thickness D1 of the outer wall meet the condition that h1 + D1 is larger than or equal to 0.9 mm and smaller than or equal to 3 mm. According to the battery monomer, the mounting quality and the mounting reliability of the pressure relief mechanism can be effectively improved, the pressure relief mechanism can be stably and reliably mounted on the thin outer wall of the shell of the battery monomer, and the energy density of the battery monomer is improved.

Description

Technical Field

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

[0002] Battery cells are usually equipped with a pressure relief mechanism. The main function of the pressure relief mechanism is to relieve pressure and vent gas. When a battery cell experiences thermal runaway, the high-temperature and high-pressure gas generated inside the battery cell can be discharged in a directional manner through the pressure relief mechanism, thereby keeping the battery cell in a stable working state.

[0003] In related technologies, the pressure relief mechanism is installed on the outer wall of the battery cell casing. Due to the installation method of the pressure relief mechanism and the structural limitations of the battery cell casing, there are problems such as high installation difficulty and low installation reliability of the pressure relief mechanism. Utility Model Content

[0004] This application aims to solve the problem of low installation reliability of pressure relief mechanisms when they are installed on the thin outer wall of the battery cell housing. To this end, this application provides a battery cell, a battery device, and an electrical device.

[0005] In a first aspect, this application provides a battery cell, comprising:

[0006] The housing includes multiple outer walls that form a receiving cavity. At least one of the outer walls has a mounting hole that communicates with the receiving cavity, and the portion of the outer wall surrounding the mounting hole is bent toward the receiving cavity to form a stepped portion.

[0007] The pressure relief mechanism includes a main body and an overlapping portion connected to the circumferential edge of the main body. The main body passes through the mounting hole, and the overlapping portion is welded to the side of the stepped portion opposite to the receiving cavity.

[0008] The thickness h1 of the overlapping part and the thickness D1 of the outer wall satisfy the following condition: 0.9mm≤h1+D1≤3mm.

[0009] The battery cell according to the first aspect of this application has at least the following beneficial effects:

[0010] The battery cell of this application is formed by bending the portion of the outer wall surrounding the mounting hole towards the receiving cavity to create a stepped portion. This reduces the probability of direct damage to the outer wall structure and does not reduce the wall thickness of the stepped portion around the mounting hole, keeping the wall thickness of the stepped portion equal to the thickness of the outer wall. At the same time, the overlapping portion of the stepped portion with the pressure relief mechanism maintains good flatness, ensuring good structural strength of the stepped portion. This improves the welding quality of the overlapping portion and the stepped portion, reduces the probability of poor welding, improves the installation quality and reliability of the pressure relief mechanism, and enables the pressure relief mechanism to be stably and reliably installed on the thinner outer wall of the battery cell casing, thereby increasing the energy density of the battery cell.

[0011] In some embodiments, the stepped portion includes a first sidewall bent relative to the outer wall and a second sidewall parallel to the outer wall, wherein the wall thickness of the first sidewall, the wall thickness of the second sidewall, and the thickness of the outer wall are equal.

[0012] This design ensures that the wall thickness at any point on the step is equal to the thickness of the outer wall, eliminating the need to thin or reduce the wall thickness of the step. Simultaneously, it maintains good flatness at the overlap between the step and the pressure relief mechanism, ensuring good structural strength. This improves the welding quality between the overlap and the step, reduces the probability of poor welding, and enhances the installation quality of the pressure relief mechanism. This allows for stable and reliable installation of the pressure relief mechanism on the thinner outer wall of the battery cell casing, thereby increasing the energy density of the battery cell.

[0013] In some embodiments, the overlapping portion is welded to the stepped portion through the weld.

[0014] This configuration, which secures the lap joint to the stepped portion, reduces the probability of weld seams between the lap joint and the stepped portion, and improves the welding quality of the lap joint and the stepped portion.

[0015] In some embodiments, the thickness h1 of the overlapping portion and the thickness D1 of the outer wall satisfy: h1 < D1.

[0016] With this design, when the lap joint is welded to the step, the thicker step provides lap positioning for the lap joint while also providing good structural support, reducing the probability of the step and lap joint being damaged during the welding process, and thus improving the welding quality of the lap joint and the step.

[0017] In some embodiments, the thickness D1 of the outer wall satisfies: 0.4mm≤D1≤1.5mm; and / or, the thickness h1 of the overlapping portion satisfies: 0.4mm≤h1≤1.5mm.

[0018] This design ensures better welding quality between the overlapping section and the stepped section formed by the bending of part of the outer wall.

[0019] In some embodiments, the housing has a side wall, a top wall, and a bottom wall, and the outer wall having the mounting hole is a side wall of the housing.

[0020] This configuration allows the pressure relief mechanism to be mounted on the side wall of the housing, reducing the assembly space occupied by the pressure relief mechanism and enabling the housing cavity to accommodate more electrode components, thereby increasing the energy density of the battery cells.

[0021] In some embodiments, along the axial direction of the mounting hole, the thickness h1 of the overlap and the depth h3 of the step satisfy: h1≤h3.

[0022] With this configuration, when the overlapping part is overlapped and welded to the wall surface of the stepped part, the entire overlapping part is located in the groove cavity formed by the stepped part, so that the overlapping part will not protrude relative to the stepped part towards the outer wall of the shell, which facilitates the protective sticker of the pressure relief mechanism to be attached to the surface of the overlapping part or the corresponding outer wall surface of the shell.

[0023] In some embodiments, the thickness h1 of the overlapping portion and the depth h3 of the stepped portion satisfy: 1 / 6 ≤ h1 / h3 ≤ 1.

[0024] This design ensures that after the overlapping part and the stepped part are welded together, the overlapping part will not protrude relative to the stepped part towards the outer wall of the shell, making it convenient for the protective sticker of the pressure relief mechanism to fit and connect with the surface of the overlapping part or the corresponding outer wall surface of the shell.

[0025] In some embodiments, the thickness h1 of the overlapping portion and the depth h3 of the step portion satisfy: 1 / 3≤h1 / h3≤1.

[0026] This design serves two purposes: firstly, it ensures that after the overlapping part and the stepped part are welded together, the overlapping part will not protrude relative to the stepped part towards the outer wall of the shell, facilitating the bonding of the protective sticker of the pressure relief mechanism with the surface of the overlapping part or the corresponding outer wall surface of the shell; secondly, it ensures that the thickness h1 of the overlapping part and the depth h3 of the stepped part will not differ too much, facilitating the welding connection operation between the overlapping part and the stepped part.

[0027] In some embodiments, the depth h3 of the step portion satisfies: 0.4mm≤h3≤2mm.

[0028] This design prevents the stepped portion from occupying too much space in the housing's cavity, allowing the housing to accommodate more electrode components and thus further improve the energy density of the battery cells.

[0029] In some embodiments, the stepped portion includes a first sidewall that bends relative to the outer wall and a second sidewall that is parallel to the outer wall, wherein the first sidewall and the second sidewall are connected by a rounded corner transition.

[0030] This design eliminates the rectangular corner structure on the side of the stepped portion near the receiving cavity, reducing the probability of structural damage to the electrode assembly due to hard collisions with the stepped portion, and correspondingly improving the structural stability and reliability of the battery cell.

[0031] In some embodiments, the thickness h2 of the main body and the thickness D1 of the outer wall satisfy: h2≤D1.

[0032] With this configuration, the main body is contained within the mounting hole under the limiting constraint of the overlapping part, preventing the main body from protruding from the side of the stepped part closer to the receiving cavity. On the one hand, this prevents the main body from occupying the space of the receiving cavity of the casing, further improving the energy density of the battery cell; on the other hand, the electrode assembly in the receiving cavity will not come into contact with or collide with the main body, ensuring that the pressure relief mechanism as a whole and the electrode assembly maintain good structural stability, thereby improving the structural stability and reliability of the battery cell.

[0033] In some embodiments, the battery cell further includes at least two electrode assemblies, all of which are disposed in the receiving cavity. Each electrode assembly includes a straight section and two corner sections. The two corner sections are connected to the two ends of the straight section along a second direction. Two adjacent corner sections along a first direction form a clearance space with the outer wall. The stepped portion and / or the pressure relief mechanism are located within the clearance space. The first direction is the thickness direction of the electrode assembly, and the second direction is the length direction of the electrode assembly.

[0034] This design ensures that the corner section at the end of the electrode assembly will not interfere with or collide with the step section and / or the pressure relief mechanism. At the same time, it allows the opposite ends of the electrode assembly to extend adaptively to the position of the outer wall of the housing, enabling the cavity to accommodate more electrode assemblies and further improve the energy density of the battery cell.

[0035] In some embodiments, a separator is provided between the pressure relief mechanism and the electrode assembly along the second direction, and the vertical projection of the pressure relief mechanism relative to the outer wall is within the vertical projection of the separator relative to the outer wall along the second direction.

[0036] With this configuration, the separator separates the pressure relief mechanism from the electrode assembly, which also prevents the end of the electrode assembly from interfering with or colliding with the pressure relief mechanism. This ensures that both the pressure relief mechanism and the electrode assembly maintain good structural stability, thereby improving the structural stability and reliability of the battery cell.

[0037] In some embodiments, the separator is spaced apart from the pressure relief mechanism along the second direction.

[0038] With this configuration, the high-temperature and high-pressure gas generated inside the containment chamber can flow to the pressure relief mechanism through the gap between the separator and the pressure relief mechanism. The pressure relief mechanism then directionally discharges the high-temperature and high-pressure gas, thereby keeping the battery cell in a stable working state.

[0039] In some embodiments, the separator has a plurality of vent holes.

[0040] With this configuration, when a battery cell experiences thermal runaway, the high-temperature and high-pressure gas generated in the containment cavity can flow to the pressure relief mechanism through the various vents on the separator. The pressure relief mechanism then directionally discharges the high-temperature and high-pressure gas, thereby keeping the battery cell in a stable working state.

[0041] Secondly, this application provides a battery device, which includes the battery cell described above.

[0042] Thirdly, this application provides an electrical device that includes the battery device described above, the battery device being used to provide electrical energy.

[0043] 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 above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0044] 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:

[0045] Figure 1 This is a schematic diagram of the vehicle structure according to an embodiment of this application.

[0046] Figure 2 This is another structural schematic diagram of the vehicle according to an embodiment of this application.

[0047] Figure 3 This is an exploded view of the battery device according to an embodiment of this application.

[0048] Figure 4 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application. Figure 1 .

[0049] Figure 5This is a partial exploded view of the battery cell structure according to an embodiment of this application.

[0050] Figure 6 This is a side view of a battery cell according to an embodiment of this application.

[0051] Figure 7 for Figure 6 A schematic diagram of the cross-sectional structure along the middle AA.

[0052] Figure 8 for Figure 7 A magnified view of a section at point B in the middle.

[0053] Figure 9 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application. Figure 2 .

[0054] Figure 10 for Figure 9 A schematic diagram of the cross-sectional structure of a single battery cell.

[0055] Figure 11 for Figure 9 A partial cross-sectional structural diagram of a battery cell.

[0056] Figure 12 This is a schematic diagram of the structure of a single battery cell according to an embodiment of this application. Figure 3 .

[0057] Figure 13 for Figure 12 A schematic diagram of the cross-sectional structure of a single battery cell.

[0058] Figure 14 for Figure 12 A partial cross-sectional structural diagram of a battery cell.

[0059] Explanation of reference numerals in the attached drawings: Battery cell 10; Housing 100; Outer wall 110; Mounting hole 111; Step portion 112; First side wall 1121; Second side wall 1122; Receiving cavity 120; Pressure relief mechanism 200; Main body portion 210; Overlap portion 220; Electrode assembly 300; Straight section 310; Corner section 320; Clearance space 330; Separator 400; Battery device 20; Box 21; Vehicle 30; Controller 40; Motor 50; First direction X; Second direction Y. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0061] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0062] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0064] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0066] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0067] A battery consists of one or more individual battery cells. For each battery, the multiple battery cells that make up it can be connected in series, in parallel, or in a mixed configuration. Among them, a mixed configuration means that multiple battery cells are connected in both series and parallel.

[0068] A battery cell is the smallest unit that makes up a battery. The structure of a battery cell includes a casing, an electrolyte, and electrode assemblies. Electrode assemblies are the components in the battery cell where electrochemical reactions occur. Electrode assemblies include a positive electrode, a negative electrode, and a separator. The casing may contain one or more electrode assemblies, which are mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is placed between the positive and negative electrode sheets.

[0069] The housing has an open end and a hollow interior. The electrode assembly is housed inside the housing, and an end cap is positioned over the opening. The end cap closes the opening to form the internal environment of the battery cell. Alternatively, the end cap and housing can be integrated. Specifically, the end cap and housing can form a common connection surface before other components are inserted into the housing. When the interior of the housing needs to be encapsulated, the end cap closes the housing. The housing can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing can be determined based on the specific shape and size of the electrode assembly. The housing can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic. This application does not impose any special limitations on these materials.

[0070] Battery cells are usually equipped with a pressure relief mechanism. The main function of the pressure relief mechanism is to relieve pressure and vent gas. When a battery cell experiences thermal runaway, the high-temperature and high-pressure gas generated inside the battery cell can be discharged in a directional manner through the pressure relief mechanism, thereby keeping the battery cell in a stable working state.

[0071] In related technologies, the pressure relief mechanism is installed on the outer wall of the battery cell casing. Specifically, the installation method involves thinning one outer wall of the casing, i.e., punching a stepped hole on the outer wall surface, and then installing the pressure relief mechanism at the stepped hole. When the pressure relief mechanism is welded to a thinner outer wall of the casing, the thinned wall thickness may not meet the required weld penetration, resulting in difficult installation, a high risk of welding defects, and low installation reliability.

[0072] Based on the above, and addressing the issue of low installation reliability when installing pressure relief mechanisms on the thin outer wall of a battery cell's casing, one or more embodiments of this application provide a battery cell that reduces the probability of direct damage to the outer wall structure by bending the portion of the outer wall surrounding the mounting hole towards the housing cavity. This does not reduce the wall thickness of the stepped portion around the mounting hole, ensuring the wall thickness of the stepped portion remains equal to the outer wall thickness. Simultaneously, the overlapping portion of the stepped portion with the pressure relief mechanism maintains good flatness, ensuring good structural strength. This improves the welding quality between the overlapping portion and the stepped portion, reduces the probability of poor welding, and enhances the installation quality and reliability of the pressure relief mechanism. This allows for stable and reliable installation of the pressure relief mechanism on the thin outer wall of the battery cell's casing, thereby increasing the energy density of the battery cell.

[0073] This application also provides a battery device, which includes the aforementioned battery cells. The battery cells can constitute the smallest unit of the battery device, and the battery device can include battery modules or battery packs, etc.

[0074] Battery devices can be used in electrical equipment that uses batteries as a power source, or in various energy storage systems that use batteries as energy storage elements. Electrical equipment can include, but is not limited to, 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.

[0075] See Figure 1 and Figure 2 , Figure 1This is a schematic diagram of the structure of a vehicle according to some embodiments of this application. The vehicle 30 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 20 is installed inside the vehicle 30, and the battery device 20 can be located at the bottom, front, or rear of the vehicle 30. The battery device 20 can be used to power the vehicle 30; for example, the battery device 20 can serve as the operating power source for the vehicle 30. The vehicle 30 may also include a controller 40 and a motor 50. The controller 40 is used to control the battery device 20 to supply power to the motor 50, for example, to meet the power needs of the vehicle 30 during starting, navigation, and driving.

[0076] Of course, in other embodiments, the battery device 20 can not only serve as the operating power source for the vehicle 30, but also as the driving power source for the vehicle 30, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 30.

[0077] See Figure 3 The battery device 20 mentioned in this application may include battery modules or battery packs, and the battery cell 10 may constitute the smallest unit of the battery device 20.

[0078] See Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 This application provides a battery cell 10, which includes a housing 100 and a pressure relief mechanism 200.

[0079] The housing 100 includes a plurality of outer walls 110, which together form a receiving cavity 120. At least one outer wall 110 has a mounting hole 111 that communicates with the receiving cavity 120, and the portion of the outer wall 110 surrounding the mounting hole 111 is bent toward the receiving cavity 120 to form a stepped portion 112.

[0080] The pressure relief mechanism 200 includes a main body 210 and an overlapping part 220 connected to the circumferential edge of the main body 210. The main body 210 passes through the mounting hole 111, and the overlapping part 220 is welded to the side of the stepped part 112 opposite to the receiving cavity 120.

[0081] The thickness h1 of the overlapping part 220 and the thickness D1 of the outer wall 110 satisfy the following condition: 0.9mm≤h1+D1≤3mm.

[0082] It should be noted that, in this application, the material of the housing 100 can be copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and preferably, the housing 100 is an aluminum housing. See also... Figure 4 and Figure 5The housing 100 can be a sealed cuboid structure. The side walls, bottom wall and top wall of the housing 100 constitute the entire outer wall 110 of the housing 100. The entire outer wall 110 is integrally connected to form an annular housing 100, so that a receiving cavity 120 is formed inside the housing 100. The receiving cavity 120 is used to receive the electrode assembly 300.

[0083] Of course, the housing 100 may also include an integrally connected body and an end cap (not shown in the figure), with the end cap covering the opening of the body to seal the receiving cavity 120. Specifically, the end cap and the body can form a common connecting surface before other components are inserted into the housing, and the end cap is then closed to seal the body when it is necessary to enclose the interior of the body. In this case, the end cap constitutes the top wall of the housing 100, and also corresponds to one outer wall 110 of the housing 100.

[0084] The mounting hole 111 on the outer wall 110 of the housing 100 can be, but is not limited to, a round hole, an elliptical hole, a square hole, etc., and its shape can be adapted to the shape of the pressure relief mechanism 200.

[0085] See also in this application. Figure 4 and Figure 5 The pressure relief mechanism 200 includes a main body 210 and an overlapping part 220 connected to the circumferential edge of the main body 210. The main body 210 refers to the pressure relief main structure of the pressure relief mechanism 200, and the overlapping part 220 refers to the lug mounting structure of the pressure relief mechanism 200.

[0086] The pressure relief mechanism 200 can be configured as an explosion-proof valve. The pressure relief mechanism 200 is installed on the corresponding outer wall 110. Its pressure relief principle is: when the battery cell 10 is in working state, when excessive pressure or temperature is generated inside the housing 100, the pressure relief mechanism 200 will automatically open to release high-pressure gas or high-temperature gas into the external environment, thereby reducing the pressure and temperature inside the housing 100 and effectively reducing the risk of battery cell 10 explosion.

[0087] The pressure relief mechanism 200 can be made of materials such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic. The housing 100 and the pressure relief mechanism 200 can be made of the same material to ensure good welding quality between the overlapping portion 220 of the pressure relief mechanism 200 and the stepped portion 112 of the housing 100.

[0088] See also in this application. Figure 5 and Figure 8The mounting holes 111 and the stepped portion 112 on the corresponding outer wall 110 of the housing 100 can be formed in the following two ways: Method 1: First, the mounting holes 111 are machined on the outer wall 110, and then the portion of the outer wall 110 surrounding the mounting holes 111 is bent a certain distance toward the receiving cavity 120 to form a stepped portion 112 with a certain depth. Method 2: First, the corresponding portion of the outer wall 110 is recessed a certain distance toward the receiving cavity 120 to form a recessed platform with a certain depth, and then the mounting holes 111 are machined on the recessed platform, so that the mounting holes 111 form a stepped portion 112 around the circumference of the mounting holes 111.

[0089] After the mounting hole 111 and the step portion 112 are formed on the outer wall 110, the main body 210 of the pressure relief mechanism 200 is inserted and installed in the mounting hole 111. The overlapping portion 220 of the pressure relief mechanism 200 and the side of the step portion 112 away from the receiving cavity 120 form an abutment limit. Then, the contact part of the overlapping portion 220 and the step portion 112 is welded to complete the installation of the pressure relief mechanism 200 and seal the mounting hole 111.

[0090] It should be noted that, in this application, see [reference needed]. Figure 8 The thickness h1 of the overlapping portion 220 of the pressure relief mechanism 200 and the thickness D1 of the outer wall 110 are both relatively thin. The sum of the thickness h1 of the overlapping portion 220 and the thickness D1 of the outer wall 110 is in the range of 0.9mm to 3mm. If the stepped portion 112 and the mounting hole 111 are directly punched on the outer wall 110, on the one hand, the structure of the outer wall 110 will be easily damaged, making it difficult to form the stepped portion 112 and the mounting hole 111; on the other hand, the wall thickness of the stepped portion 112 around the mounting hole 111 will be further reduced, resulting in poor welding between the overlapping portion 220 and the stepped portion 112. It will be difficult to stably and reliably install the pressure relief mechanism 200 on the thin outer wall of the housing 100 of the battery cell 10, making it difficult to improve the energy density of the battery cell 10.

[0091] Based on this, this application reduces the probability of directly damaging the structure of the outer wall 110 by bending the portion of the outer wall 110 surrounding the mounting hole 111 towards the receiving cavity 120 to form a stepped portion 112, without reducing the wall thickness of the stepped portion 112 around the mounting hole 111, thus keeping the wall thickness of the stepped portion 112 equal to the thickness of the outer wall 110. At the same time, it maintains good flatness at the portion of the stepped portion 112 that overlaps with the overlapping portion 220 of the pressure relief mechanism 200, thereby maintaining good structural strength of the stepped portion 112. This improves the welding quality of the overlapping portion 220 and the stepped portion 112, reduces the probability of poor welding between the overlapping portion 220 and the stepped portion 112, improves the installation quality and reliability of the pressure relief mechanism 200, and enables the pressure relief mechanism 200 to be stably and reliably installed on the thinner outer wall of the housing 100 of the battery cell 10, thereby increasing the energy density of the battery cell 10.

[0092] In some embodiments of this application, see Figure 4 , Figure 7 and Figure 8 The step portion 112 includes a first side wall 1121 that is bent relative to the outer wall 110 and a second side wall 1122 that is parallel to the outer wall 110. The wall thickness of the first side wall 1121, the wall thickness of the second side wall 1122 and the thickness of the outer wall 110 are equal.

[0093] Specifically, the stepped portion 112 is in the shape of a rectangular groove, with a mounting hole 111 penetrating the middle of the groove. The bottom wall of the groove constitutes the second side wall 1122 of the stepped portion 112, and the side walls of the groove constitute the first side wall 1121 of the stepped portion 112. It is easy to understand that the second side wall 1122 of the stepped portion 112 is the wall surface that contacts and engages with the overlapping portion 220 of the pressure relief mechanism 200, that is, the second side wall 1122 of the stepped portion 112 is for the overlapping portion 220 of the pressure relief mechanism 200 to overlap.

[0094] Let D2 be the thickness of the first sidewall 1121 of the step portion 112 and D3 be the thickness of the second sidewall 1122 of the step portion 112. Then D2 = D3 = D1.

[0095] By bending the portion of the outer wall 110 surrounding the mounting hole 111 toward the receiving cavity 120 to form a stepped portion 112, the first side wall 1121 and the second side wall 1122 constituting the stepped portion 112 are both equal in thickness to the outer wall 110. This means that the wall thickness at any position of the stepped portion 112 is equal to the thickness of the outer wall 110, without needing to thin or reduce the wall thickness of the stepped portion 112. At the same time, the portion of the stepped portion 112 that overlaps with the overlapping portion 220 maintains good flatness, and the stepped portion 112 maintains good structural strength. This improves the welding quality between the overlapping portion 220 and the stepped portion 112, reduces the probability of poor welding between the overlapping portion 220 and the stepped portion 112, improves the installation quality and reliability of the pressure relief mechanism 200, and enables the pressure relief mechanism 200 to be stably and reliably installed on the thinner outer wall of the housing 100 of the battery cell 10, thereby increasing the energy density of the battery cell 10.

[0096] Furthermore, the lap joint 220 is connected to the step joint 112 by through welding.

[0097] Specifically, the stepped portion 112 is a groove with an opening facing the outside of the housing 100, and the mounting hole 111 passes through the middle of the groove. Correspondingly, the main body 210 of the pressure relief mechanism 200 is a columnar body adapted to the shape of the mounting hole 111, and the overlapping portion 220 is a sheet-like structure surrounding the circumferential edge of the main body 210.

[0098] When the overlapping part 220 overlaps with the corresponding wall surface of the step part 112, the overlapping part 220 and the step part 112 form a surface-to-surface fit. Then, the overlapping part 220 and the step part 112 are connected and fixed by a through welding process, so that the overlapping part 220 and the step part 112 are integrally connected, eliminating the gap between the overlapping part 220 and the step part 112, and realizing the sealed assembly of the pressure relief mechanism 200.

[0099] By using a through-welding method to connect and fix the lap portion 220 and the step portion 112, the probability of weld seams appearing between the lap portion 220 and the step portion 112 can be reduced, the connection strength between the lap portion 220 and the step portion 112 can be improved, and the installation sealing performance of the pressure relief mechanism 200 can also be improved accordingly.

[0100] In some embodiments of this application, see Figure 4 , Figure 7 and Figure 8 The thickness h1 of the overlapping part 220 and the thickness D1 of the outer wall 110 satisfy: h1 < D1.

[0101] It should be understood that since the stepped portion 112 is formed by bending the portion of the outer wall 110 surrounding the mounting hole 111 toward the receiving cavity 120, the wall thickness of the stepped portion 112 is equal to the thickness of the outer wall 110, both being equal to D1.

[0102] The thickness h1 of the lap portion 220 is set to be less than the thickness D1 of the outer wall 110, which corresponds to the thickness h1 of the lap portion 220 being less than the wall thickness of the step portion 112. Thus, when the lap portion 220 is welded to the step portion 112, the thicker step portion 112 provides lap positioning for the lap portion 220 while also providing good structural support, reducing the probability of welding damage to both the step portion 112 and the lap portion 220 during the welding process, thereby improving the welding quality between the lap portion 220 and the step portion 112.

[0103] In some embodiments of this application, the thickness D1 of the outer wall 110 satisfies: 0.4mm≤D1≤1.5mm, and the thickness h1 of the overlapping portion 220 satisfies: 0.4mm≤h1≤1.5mm.

[0104] Specifically, the thickness D1 of the outer wall 110 can be 0.4mm, 0.6mm, 0.9mm, 1.5mm, etc. The thickness h1 of the overlapping part 220 can be 0.4mm, 0.5mm, 0.8mm, 1.5mm, etc.

[0105] In some specific embodiments, the thickness D1 of the outer wall 110 is 0.9 mm, and the thickness h1 of the overlap 220 is 0.7 mm. In this case, the sum of the thickness h1 of the overlap 220 and the thickness D1 of the outer wall 110 is less than 3 mm. At the same time, the thickness h1 of the overlap 220 is less than the thickness D1 of the outer wall 110, so that the overlap 220 and the stepped portion 112 formed by bending part of the outer wall 110 have better welding quality.

[0106] Of course, in other embodiments, the thickness D1 of the outer wall 110 and the thickness h1 of the overlapping portion 220 can also be other values, such that the thickness h1 of the overlapping portion 220 and the thickness D1 of the outer wall 110 satisfy 0.9mm≤h1+D1≤3mm and h1<D1, and there is no specific limitation.

[0107] In some embodiments of this application, see Figure 4 and Figure 5 The housing 100 has a side wall, a top wall and a bottom wall, and the outer wall 110 with mounting holes 111 is the side wall of the housing 100.

[0108] It should be noted that the top wall and bottom wall of the housing 100 refer to the upper end wall and lower end wall of the housing 100, respectively, and the side walls of the housing 100 refer to the front and rear end walls and the left and right end walls of the housing 100.

[0109] In one specific embodiment, the housing 100 includes a body and an end cap (not shown in the figure). The top of the body is open, forming an internal receiving cavity 120. The end cap is disposed on the opening of the body. The end cap can be integrally connected to the body or detachably connected. The end cap forms the top wall of the housing 100, and the bottom wall and side walls of the body correspondingly form the bottom wall and side walls of the housing 100.

[0110] In the housing 100 structure of the battery cell 10, the thickness of the side wall of the housing 100 is generally thinner than the thickness of the top and bottom walls of the housing 100. The mounting hole 111 is opened on the side wall of the housing 100 so that the pressure relief mechanism 200 is correspondingly assembled on the side wall of the housing 100. This can reduce the assembly space occupied by the pressure relief mechanism 200, and allow the receiving cavity 120 inside the housing 100 to accommodate and assemble more electrode components 300, thereby improving the energy density of the battery cell 10.

[0111] It should be noted that in this application, when the pressure relief mechanism 200 is installed on the corresponding outer wall 100 of the housing 100, a protective patch (not shown in the figure) is affixed to the side surface of the outer wall 100 facing away from the receiving cavity 120 of the housing 100 or the side surface of the overlapping part 220 facing away from the receiving cavity 120 of the housing 100, so as to reduce the probability of structural damage to the pressure relief mechanism 200 due to impact or collision during use.

[0112] Based on this, in some embodiments of this application, see [reference] Figure 6 , Figure 7 and Figure 8 Along the axial direction of the mounting hole 111, the thickness h1 of the overlapping portion 220 and the depth h3 of the stepped portion 112 satisfy: h1≤h3.

[0113] It is easy to understand that during the forming process of the stepped portion 112 on the housing 100, the portion of the outer wall 110 surrounding the mounting hole 111 is bent a certain distance toward the receiving cavity 120 to form the stepped portion 112. The stepped portion 112 has a groove structure with a certain depth, and the depth h3 of the stepped portion 112 refers to the depth of the groove.

[0114] By setting the thickness h1 of the overlapping portion 220 to be less than or equal to the depth h3 of the step portion 112, when the overlapping portion 220 is overlapped and welded to the wall surface of the step portion 112, the overlapping portion 220 is entirely located in the groove cavity formed by the step portion 112, so that the overlapping portion 220 will not protrude relative to the step portion 112 toward the outer wall 100 of the housing 100, which facilitates the bonding connection between the protective patch of the pressure relief mechanism 200 and the surface of the overlapping portion 220 or the corresponding surface of the outer wall 110 of the housing 100.

[0115] See also some embodiments of this application. Figure 6 , Figure 7 and Figure 8 The thickness h1 of the overlapping part 220 and the depth h3 of the step part 112 satisfy: 1 / 6≤h1 / h3≤1.

[0116] Specifically, the thickness h1 of the overlapping part 220 satisfies: 0.4mm≤h1≤1.5mm, and the depth h3 of the step part 112 satisfies 2mm≤h3≤3mm.

[0117] If the thickness h1 of the overlapping part 220 is 0.7 mm and the depth h3 of the step part 112 is 1.4 mm, then the depth h3 of the step part 112 is twice the thickness h1 of the overlapping part 220. After the overlapping part 220 is overlapped and welded to the wall surface of the step part 112, there is still a gap space of 0.7 mm in the cavity of the step part 112, so that the protective patch of the pressure relief mechanism 200 can be attached to the surface of the overlapping part 220 or the corresponding outer wall 110 surface of the housing 100.

[0118] It is understandable that by controlling the ratio between the thickness h1 of the overlapping portion 220 and the depth h3 of the step portion 112 within the range of 1 / 6 to 1, the overlapping portion 220 will not protrude relative to the step portion 112 toward the outer wall 100 of the housing 100 after the overlapping portion 220 and the step portion 112 are welded together, thus facilitating the bonding connection between the protective patch of the pressure relief mechanism 200 and the surface of the overlapping portion 220 or the corresponding surface of the outer wall 110 of the housing 100.

[0119] Furthermore, the thickness h1 of the overlapping portion 220 and the depth h3 of the step portion 112 satisfy: 1 / 3≤h1 / h3≤1.

[0120] This design serves two purposes: firstly, it ensures that after the overlapping portion 220 and the stepped portion 112 are welded together, the overlapping portion 220 will not protrude relative to the stepped portion 112 toward the outer wall 100 of the housing 100, facilitating the fitting and connection of the protective patch of the pressure relief mechanism 200 with the surface of the overlapping portion 220 or the corresponding surface of the outer wall 110 of the housing 100; secondly, it ensures that the thickness h1 of the overlapping portion 220 and the depth h3 of the stepped portion 112 will not differ too much, facilitating the welding connection operation between the overlapping portion 220 and the stepped portion 112.

[0121] See also some embodiments of this application. Figure 6 , Figure 7 and Figure 8 The depth h3 of the step 112 satisfies: 0.4mm≤h3≤2mm.

[0122] Specifically, the depth h3 of the step portion 112 can be 0.4mm, 0.8mm, 1.5mm, 2mm, etc.

[0123] By setting the depth h3 of the step portion 112 in the range of 0.4mm to 2mm, the step portion 112 will not occupy too much space in the receiving cavity 120 of the housing 100, so that the receiving cavity 120 in the housing 100 can accommodate more electrode components 300, thereby further improving the energy density of the battery cell 10.

[0124] In this application, since the stepped portion 112 is recessed toward the receiving cavity 120 of the housing 100, the stepped portion 112 will occupy part of the space of the receiving cavity 120 along the recessed direction. When the electrode assembly 300 is installed in the receiving cavity 120, there is a risk that the electrode assembly 300 will come into contact with and collide with the rectangular corner of the stepped portion 112, which may easily lead to damage to the structure of the electrode assembly 300.

[0125] Based on this, see also some embodiments of this application. Figure 6 , Figure 7 and Figure 8 The step portion 112 includes a first side wall 1121 that is bent relative to the outer wall 110 and a second side wall 1122 that is parallel to the outer wall 110. The first side wall 1121 and the second side wall 1122 are connected by a rounded corner transition.

[0126] Specifically, the stepped portion 112 is in the shape of a rectangular groove, and the mounting hole 111 passes through the middle of the groove. The bottom wall of the groove constitutes the second side wall 1122 of the stepped portion 112, and the side wall of the groove constitutes the first side wall 1121 of the stepped portion 112. The second side wall 1122 and the second side wall 1122 are connected by a rounded corner.

[0127] This configuration eliminates the rectangular corner structure on the side of the stepped portion 112 near the receiving cavity 120, reduces the probability of structural damage to the electrode assembly 300 due to hard collision with the stepped portion 112, and further improves the structural stability and reliability of the battery cell 10.

[0128] See also some embodiments of this application. Figure 6 , Figure 7 and Figure 8 The thickness h2 of the main body 210 and the thickness D1 of the outer wall 110 satisfy: h2≤D1.

[0129] It is easy to understand that in this application, the mounting hole 111 is provided through the corresponding outer wall 110 of the housing 100, and the depth of the mounting hole 111 is equal to the thickness D1 of the outer wall 110.

[0130] When the overlapping part 220 of the pressure relief mechanism 200 is overlapped and welded to the wall surface of the step part 112, the main body part 210 of the pressure relief mechanism 200 passes through the mounting hole 111. Since the thickness h2 of the main body part 210 is less than or equal to the thickness D1 of the outer wall 110, the thickness h2 of the main body part 210 is less than the depth of the mounting hole 111.

[0131] Thus, under the limiting constraint of the overlapping portion 220, the main body 210 is entirely within the mounting hole 111, preventing the main body 210 from protruding relative to the side of the stepped portion 112 near the receiving cavity 120. On the one hand, this prevents the main body 210 from occupying the space of the receiving cavity 120 of the housing 100, further improving the energy density of the battery cell 10. On the other hand, the electrode assembly 300 in the receiving cavity 120 will not come into contact with or collide with the main body 210, ensuring that the pressure relief mechanism 200 as a whole and the electrode assembly 300 maintain good structural stability, further improving the structural stability and reliability of the battery cell 10.

[0132] In some embodiments of this application, see Figure 9 , Figure 10 and Figure 11 The battery cell also includes at least two electrode assemblies 300. All electrode assemblies 300 are disposed in the receiving cavity 120. The electrode assembly 300 includes a straight section 310 and two corner sections 320. The two corner sections 320 are connected to the two ends of the straight section 310 along the second direction Y. Two adjacent corner sections 320 along the first direction X and the outer wall 110 form a clearance space 330. The step portion 112 and / or the pressure relief mechanism 200 are located in the clearance space 330. The first direction X is the thickness direction of the electrode assembly 300, and the second direction Y is the length direction of the electrode assembly 300.

[0133] It should be noted that, in this application, all electrode assemblies 300 can be stacked side by side along the length, width, or height of the receiving cavity 120.

[0134] The electrode assembly 300 is a wound electrode assembly, for example, the electrode assembly 300 is generally an integral structure with semi-cylindrical ends and a rectangular middle section. Two corner segments 320 are connected to the two ends of the straight segment 310 along its length. When the electrode assembly 300 is installed in the receiving cavity 120, the two corner segments 320 on the electrode assembly 300 are adjacent to the two outer walls 110 of the housing 100 along its length, respectively.

[0135] It should be understood that the two adjacent corner segments 320 along the first direction X refer to the corner segment 320 on the electrode assembly 300 near the pressure relief mechanism 200 and the corner segment 320 on the adjacent electrode assembly 300 near the pressure relief mechanism 200 along the first direction X. After all the electrode assemblies 300 are stacked side by side, a flared structure extending outward from the housing 100 will be formed between the two adjacent corner segments 320 along the first direction X. This flared structure and the corresponding outer wall 110 of the housing 100 form a clearance space 330, and the step portion 112 and / or the pressure relief mechanism 200 are located within the clearance space 330.

[0136] This configuration ensures that the ends of the electrode assembly 300 do not interfere with or collide with the step portion 112 and / or the pressure relief mechanism 200. At the same time, it allows the corner segments 320 at the opposite ends of the electrode assembly 300 to extend adaptively to the position of the outer wall 110 of the housing 100, so that more electrode assemblies 300 can be installed in the receiving cavity 120, further improving the energy density of the battery cell 10.

[0137] In some embodiments of this application, see Figure 12 , Figure 13 and Figure 14 Along the second direction Y, a separator 400 is provided between the pressure relief mechanism 200 and the electrode assembly 300, and the vertical projection of the pressure relief mechanism 200 relative to the outer wall 110 is within the vertical projection of the separator 400 relative to the outer wall 110.

[0138] Specifically, with reference to the position of the housing 100, the partition 400 and the pressure relief mechanism 100 are located on the same side. The partition 400 can be a cover structure disposed within the receiving cavity 120 of the housing 100, which covers the pressure relief mechanism 100 in the direction of the pressure relief mechanism 100. The partition 400 can also be a strip connecting the top and bottom walls of the housing 100, or a strip connecting the two outer walls 100 of the housing 100 along the first direction X.

[0139] The shape of the separator 400 is not specifically limited. The shape and installation position of the separator 400 in the receiving cavity 120 of the housing 100 are such that the vertical projection of the pressure relief mechanism 200 relative to the outer wall 110 is within the vertical projection of the separator 400 relative to the outer wall 110, so that the separator 400 can completely cover the pressure relief mechanism 200 and the end of the electrode assembly 300 will not interfere with or collide with the pressure relief mechanism 200.

[0140] It should be noted that in this application, along the second direction Y, the vertical projection of the step portion 112 relative to the outer wall 110 is also within the vertical projection of the separator 400 relative to the outer wall 110, so that the separator 400 completely covers the step portion 112, so that the end of the electrode assembly 300 will not interfere with or collide with the step portion 112, and the electrode assembly 300 maintains good structural stability.

[0141] It is easy to understand that by setting a separator 400 between the pressure relief mechanism 200 and all the electrode assemblies 300, the separator 400 separates the pressure relief mechanism 100 from the electrode assembly 300, thus preventing the end of the electrode assembly 300 from interfering with or colliding with the pressure relief mechanism 200. This ensures that both the pressure relief mechanism 200 as a whole and the electrode assembly 300 maintain good structural stability, further improving the structural stability and reliability of the battery cell 10.

[0142] Further, see Figure 12 , Figure 13 and Figure 14 Along the second direction Y, the separator 400 and the pressure relief mechanism 200 are spaced apart.

[0143] Specifically, the separator 400 can be constructed as a thin sheet or strip with good structural strength, reducing the space occupied by the separator 400 in the housing cavity 120 of the housing 100, and further improving the energy density of the battery cell 10.

[0144] It is understandable that a gap space is formed between the separator 400 and the pressure relief mechanism 200. When the battery cell 10 experiences thermal runaway, the high-temperature and high-pressure gas generated in the containment cavity 120 can flow to the pressure relief mechanism 100 through the gap space between the separator 400 and the pressure relief mechanism 200. The pressure relief mechanism 100 then directionally discharges the high-temperature and high-pressure gas, thereby keeping the battery cell 10 in a stable working state.

[0145] Furthermore, the separator 400 has multiple vent holes.

[0146] Specifically, the separator 400 is a sheet or strip, and all the vents are arrayed on the separator 400, so that all the vents form a dense venting channel.

[0147] When thermal runaway occurs in the battery cell 10, the high-temperature and high-pressure gas generated in the containment cavity 120 can flow to the pressure relief mechanism 100 through the various vents on the separator 400. The pressure relief mechanism 100 then discharges the high-temperature and high-pressure gas in a directional manner, thereby keeping the battery cell 10 in a stable working state.

[0148] This application also provides a battery device 20, which includes the battery cell 10 of any of the above embodiments.

[0149] Specifically, the battery device 20 can be a battery module composed of one or more battery cells 10. For the battery device 20, the multiple battery cells 10 that make up it can be connected in series, in parallel, or in a mixed manner. Among them, a mixed manner means that the multiple battery cells 10 are connected in both series and parallel.

[0150] See Figure 3 The battery device 20 can also be a battery pack formed by placing multiple battery cells 10 in the housing 21.

[0151] It is easy to understand that the battery device 20 of this application embodiment, because it is equipped with the above-mentioned battery cell 10, has better reliability in use, which is beneficial to improving the reliability and service life of the battery device 20.

[0152] This application also provides an electrical device, which includes the battery device 20 of any of the above embodiments.

[0153] Specifically, see Figure 1 and Figure 2 The electrical equipment can be vehicles (30), mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose special limitations on the above-mentioned electrical equipment.

[0154] The electrical equipment in this application embodiment is equipped with the above-mentioned battery device, which improves the reliability of the electrical equipment and extends its service life.

[0155] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0156] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized by, The shell comprises a plurality of outer walls surrounding a receiving cavity, at least one of the outer walls is provided with a mounting hole communicating with the receiving cavity, and a portion of the outer wall surrounding the mounting hole is bent towards the receiving cavity to form a stepped portion; The pressure relief mechanism comprises a main body portion and a lap joint portion connected to the circumferential edge of the main body portion, the main body portion is arranged in the mounting hole, and the lap joint portion is welded to the side of the stepped portion away from the receiving cavity; The thickness h1 of the lap joint portion and the thickness D1 of the outer wall satisfy 0.9mm≤h1+D1≤3mm. The stepped portion comprises a first side wall bent relative to the outer wall and a second side wall parallel to the outer wall, the wall thickness of the first side wall, the wall thickness of the second side wall and the thickness of the outer wall are equal.

2. The battery cell of claim 1, wherein, The lap joint portion and the stepped portion are connected by penetration welding.

3. The battery cell of claim 1, wherein, The thickness h1 of the lap joint portion and the thickness D1 of the outer wall satisfy h1 4. The battery cell of claim 1, wherein, The thickness D1 of the outer wall satisfies 0.4mm≤D1≤1.5mm, and / or the thickness h1 of the lap joint portion satisfies 0.4mm≤h1≤1.5mm.

5. The battery cell of claim 1, wherein, The shell has a side wall, a top wall and a bottom wall, and the outer wall provided with the mounting hole is the side wall of the shell.

6. The battery cell of claim 1, wherein, Along the axial direction of the mounting hole, the thickness h1 of the lap joint portion and the depth h3 of the stepped portion satisfy h1≤h3.

7. The battery cell of claim 1, wherein, The thickness h1 of the lap joint portion and the depth h3 of the stepped portion satisfy 1 / 6≤h1 / h3≤1.

8. The battery cell of claim 7, wherein, The thickness h1 of the lap joint portion and the depth h3 of the stepped portion satisfy 1 / 3≤h1 / h3≤1.

9. The battery cell of claim 8, wherein, The depth h3 of the stepped portion satisfies 0.4mm≤h3≤2mm.

10. The battery cell of any one of claims 1 to 9, wherein, The stepped portion comprises a first side wall bent relative to the outer wall and a second side wall parallel to the outer wall, and the first side wall and the second side wall are connected by a rounded corner transition.

11. The battery cell of any one of claims 1 to 9, wherein, The thickness h2 of the main body portion and the thickness D1 of the outer wall satisfy h2≤D1.

12. The battery cell of any one of claims 1 to 9, wherein, The battery monomer further comprises at least two electrode assemblies, all of the electrode assemblies are arranged in the receiving cavity, the electrode assembly comprises a flat section and two corner sections, the two corner sections are connected to the two ends of the flat section in a second direction, adjacent two corner sections in a first direction and the outer wall surround an avoiding space, the stepped portion and / or the pressure relief mechanism are in the avoiding space, the first direction is the thickness direction of the electrode assembly, and the second direction is the length direction of the electrode assembly.

13. The battery cell of any one of claims 1 to 9, wherein, Along the second direction, a partition is arranged between the pressure relief mechanism and the electrode assembly, and the vertical projection of the pressure relief mechanism relative to the outer wall is in the vertical projection of the partition relative to the outer wall.

14. The battery cell of claim 13, wherein, Along the second direction, the partition is arranged in a spaced manner relative to the pressure relief mechanism.

15. The battery cell of claim 14, wherein, A plurality of air holes are arranged on the partition.

16. The battery cell of claim 14, wherein, The battery monomer comprises any one of the battery monomers according to claims 1 to 16.

17. A battery device characterized by comprising: The battery device comprises the battery device according to claim 17, and is used for providing electric energy.

18. An electrical device, characterized by ​

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