Battery device, welding method, electric device and energy storage device

Abstract

The application provides a battery device, a welding method, a power utilization device and an energy storage device, and belongs to the technical field of batteries. The battery device comprises a battery monomer assembly and a box body. The battery monomer assembly comprises at least one battery monomer. The box body comprises a main body and a protection piece. The main body comprises a bottom wall and a side wall connected to the edge of the bottom wall. The bottom wall and the side wall enclose an accommodation area for accommodating the battery monomer assembly. The protection piece is arranged on the outer side of the bottom wall away from the accommodation area. The bottom wall is provided with a mounting portion. The protection piece is provided with a matching portion. The mounting portion is connected to the matching portion in interference fit. The matching portion comprises a plurality of bosses. The bosses protrude from the protection piece along a first direction. The top surface of the boss is further provided with at least one protrusion protruding from the top surface along the first direction. The side wall has a connecting surface facing the bottom wall. The protrusion is welded to the connecting surface. The application can reduce the cost and assembly process of the battery device, improve the space utilization, and further improve the energy density of the battery device.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery device, welding method, power supply device, and energy storage device. Background Technology

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

[0003] In related technologies, the battery casing is usually used as the main protective component to protect the battery. The production cost of the casing directly affects the manufacturing cost of the battery. How to reduce the production cost of the casing has always been a key issue of concern in this field. Summary of the Invention

[0004] This application aims to at least address one of the technical problems existing in the prior art. Therefore, one object of this application is to provide a battery device, welding method, power supply device, and energy storage device to reduce the cost of the casing in related technologies.

[0005] An embodiment of the first aspect of this application provides a battery device, including: a battery cell assembly and a housing, the battery cell assembly including at least one battery cell; the housing including a main body and a protective member, the main body including a bottom wall and a side wall connected to the edge of the bottom wall, the bottom wall and the side wall forming a receiving area for accommodating the battery cell assembly, the protective member being disposed on the outer side of the bottom wall away from the receiving area; the bottom wall being provided with a mounting portion, the protective member being provided with a mating portion, the mounting portion being interference-fitted to the mating portion; the mating portion including a plurality of bosses, the bosses protruding from the protective member along a first direction, the top surface of the bosses also being provided with at least one protrusion protruding from the top surface along the first direction, the side wall having a connecting surface facing the bottom wall, the protrusion being welded to the connecting surface, wherein the first direction is the direction in which the protective member faces the receiving area.

[0006] In the technical solution of this application embodiment, the interference fit connection eliminates the need for standard parts such as bolts and nuts compared to bolted connections in related technologies, reducing costs and simplifying the assembly process. Furthermore, compared to thermoplastic self-tapping screw connections, it eliminates the need for additional thermoplastic tools and strict control of thermoplastic parameters, further reducing costs and simplifying the assembly process. Additionally, the interference fit connection in this embodiment eliminates the need for reserved space for standard parts piercing and assembly operations, improving space utilization and thus increasing the energy density of the battery device. Simultaneously, the interference fit connection eliminates the need for thermoplasticizing, making the material less prone to deformation and less likely to create gaps between the bottom wall and protective components due to vibration, which improves the sealing performance of the casing, thereby enhancing the reliability of the casing and the lifespan of the battery device. By setting protrusions on the boss, the protrusions can be welded to the connecting surface of the side wall. Thus, the protective parts, bottom wall and side wall can be connected together by welding the protrusions and connecting surfaces. This simplifies the assembly process of the box and eliminates the need to drill holes in the side wall to install standard parts such as bolts, as well as the need for pre-riveting, assembly and other processes. This further reduces the number of parts, simplifies the manufacturing process, improves production efficiency and reduces costs, and also improves the structural strength of the side wall and box.

[0007] In some embodiments, the mounting portion includes a plurality of mounting holes spaced apart along the edge of the bottom wall, and the mating portion includes a plurality of bosses spaced apart along the edge of the protective member, with each boss being interference-fitted into a mounting hole.

[0008] The interference fit between the boss and the mounting hole allows for a connection between the bottom wall and the protective component. This design is simple, easy to manufacture, and eliminates the need for bolts or other standard parts, thus reducing costs. Furthermore, the interference fit between the boss and the mounting hole is readily implemented, simplifying the assembly process and improving the structural strength of the bottom wall.

[0009] In some embodiments, the interference D of the interference fit between the boss and the mounting hole satisfies 0.1mm≤D≤0.3mm.

[0010] In this embodiment, by setting the interference fit to be no less than 0.1mm, the boss and the mounting hole can be tightly connected, improving the reliability of the connection and making it less prone to loosening. Setting the interference fit to be no more than 0.3mm can mitigate the problem of deformation or damage to one of the components during installation when the size difference between the two is too large.

[0011] In some embodiments, the two protrusions on each boss are respectively a first protrusion and a second protrusion. The first protrusion is used to contact and connect with the first electrode of the welding equipment, and the second protrusion is used to contact and connect with the second electrode of the welding equipment.

[0012] In this embodiment, by contacting the first electrode with the first protrusion and the second electrode with the second protrusion, a single-sided double-spot welding method can be used on one side of the protective component to form a closed circuit loop through two symmetrical electrodes. This results in a short and stable welding current path, leading to a more stable weld nugget formation. Both protrusions can be welded to the connection surface simultaneously, improving welding efficiency. It also reduces heat input to the welding area, mitigating deformation of the protective component caused by overheating. Furthermore, the electrode arrangement is not limited by the housing structure, making it more flexible in use.

[0013] In some embodiments, a first adhesive layer is provided between the connecting surface and the bottom wall, and between the connecting surface and the boss.

[0014] In this embodiment, the first adhesive layer can improve the connection strength between the boss and the sidewall, as well as between the bottom wall and the sidewall, and can also play a sealing role, improving the corrosion failure caused by water vapor and other substances entering the connection gap between the bottom wall and the sidewall.

[0015] In some embodiments, the protrusion, boss, and protective element are integrally formed.

[0016] By using a one-piece molded protective component, secondary splicing is eliminated during processing, saving mold development costs and reducing processing costs. Furthermore, the resulting protective component has no splicing welds, exhibiting excellent structural integrity. This significantly improves the fatigue strength and impact resistance of the protective component and the boss, while simplifying processing steps and reducing the risk of seal failure caused by splicing.

[0017] In some embodiments, a second adhesive layer is provided between the protective member and the bottom wall, and a portion of the second adhesive layer is located between the mounting portion and the mating portion.

[0018] In this embodiment, by providing a second adhesive layer between the bottom wall and the protective component, the bottom wall and the protective component can be connected through both interference fit and adhesive bonding, thereby improving the connection strength between them. Furthermore, since the second adhesive layer can fill the space between the bottom wall and the protective component, and can be located between the boss and the mounting hole, it achieves a dual sealing structure of mechanical interlocking and adhesive sealing while simultaneously providing a seal through the interference fit. This further enhances the sealing effect. Compared to a single sealing method, it improves sealing reliability and addresses the problem of poor airtightness of the enclosure in related technologies.

[0019] In some embodiments, the bottom wall includes a heat exchanger, a side wall is connected to the edge of the heat exchanger, the heat exchanger has a channel inside for the flow of heat exchange fluid, and the heat exchanger is thermally connected to the battery cell assembly.

[0020] In this embodiment, using a heat exchanger as the bottom wall of the housing simplifies the housing structure while allowing for cooling and heat exchange of the individual battery cells. The protective component safeguards the heat exchanger, mitigating issues such as breakage due to impacts.

[0021] In some embodiments, the sidewall includes a side beam having an internal cavity, the side beam having a connecting surface facing the bottom wall, the connecting surface being connected to the bottom wall.

[0022] In this embodiment, by setting side beams with cavities inside, the strength of the box and its anti-collision and buffering performance can be improved. In addition, the side beams can also provide a larger connection surface to facilitate welding with protrusions and increase the area of ​​the first adhesive layer, thereby further improving the connection strength between the side beams and the bottom wall and the protective components, and thus enhancing the structural strength of the box.

[0023] In some embodiments, the protective member is provided with at least one reinforcing portion protruding in a direction away from the receiving area.

[0024] This embodiment improves the structural strength of the protective component by adding a reinforcing part, thereby enhancing its protective effect on the bottom wall. The reinforcing part can protrude in a direction away from the receiving area, eliminating the need for pre-reserved space between the bottom wall and the protective component, thus reducing installation gaps between the bottom wall and the protective component and improving airtightness.

[0025] An embodiment of the second aspect of this application provides a welding method for a battery device of any of the above embodiments. The bottom wall of the battery device is provided with a plurality of mounting holes, and a protective member of the battery device is provided with a plurality of bosses protruding from the protective member along a first direction. Each boss is interference-fitted into a mounting hole. The top surface of the boss is also provided with at least one protrusion protruding from the top surface along the first direction, wherein the first direction is the direction in which the protective member faces the receiving area of ​​the battery device. The method includes: contacting a first electrode of a welding device with a first protrusion, and contacting a second electrode of a welding device with a second protrusion, wherein the first protrusion and the second protrusion are two protrusions on each boss, and the first electrode and the second electrode are located on the same side of the protective member away from the receiving area; supplying power to the first electrode and the second electrode to weld the first protrusion and the second protrusion to a connecting surface, wherein the connecting surface is the surface of the side wall of the battery device facing the bottom wall.

[0026] In this embodiment, by contacting the first electrode with the first protrusion and the second electrode with the second protrusion, a single-sided double-spot welding method can be used on one side of the protective component to form a closed circuit loop through two symmetrical electrodes. This results in a short and stable welding current path, leading to a more stable weld nugget formation. Both protrusions can be welded to the connection surface simultaneously, improving welding efficiency. It also reduces heat input to the welding area, mitigating deformation of the protective component caused by overheating. Furthermore, the electrode arrangement is not limited by the housing structure, making it more flexible in use.

[0027] In some embodiments, the axis of the first electrode coincides with the center line of the first protrusion, and the axis of the second electrode coincides with the center line of the second protrusion; and the first electrode and the second electrode are of the same size.

[0028] In this embodiment, by aligning the axis of the first electrode with the center line of the first protrusion and aligning the axis of the second electrode with the center line of the second protrusion, the current and pressure can be uniformly concentrated on the protrusion, which is beneficial to forming a high-quality, high-strength weld nugget.

[0029] An embodiment of the third aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0030] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery device in the above embodiments, and the energy storage device is used to store electrical energy.

[0031] 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, specific embodiments of this application are given below. Attached Figure Description

[0032] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0033] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0034] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0035] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0036] Figure 4 for Figure 2 Top view of the middle box;

[0037] Figure 5 for Figure 4 Top view;

[0038] Figure 6 for Figure 5 A partial schematic diagram of point A in the middle;

[0039] Figure 7 for Figure 6 A partial schematic diagram at point B in the middle;

[0040] Figure 8 This application provides welding diagrams of the housing in some embodiments;

[0041] Figure 9 This is a schematic flowchart illustrating a welding method provided in some embodiments of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1000 vehicles;

[0044] Battery unit 100, controller 200, motor 300;

[0045] Battery cell assembly 10, battery cell 11, end cap 12, housing 13, electrode assembly 14, box 20, first part 21, second part 22;

[0046] Main body 400, bottom wall 410, mounting part 411, mounting hole 412, heat exchanger 413, side wall 420, connecting surface 421, first adhesive layer 422, side beam 423, receiving area 430;

[0047] Protective component 500, mating part 510, boss 511, top surface 512, protrusion 520, first protrusion 521, second protrusion 522, second adhesive layer 530, reinforcing part 540;

[0048] Welding equipment 600, first electrode 610, second electrode 620. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "a and / or b" can represent three cases: a exists alone, a and b exist simultaneously, and b exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0054] 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).

[0055] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0056] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0057] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, the market demand is also constantly increasing.

[0058] In related technologies, the battery casing typically includes a cold plate and a bottom protective plate located at the bottom of the cold plate. The individual battery cells are located on the side of the cold plate facing away from the bottom protective plate, which is usually used to protect the cold plate. The cold plate and the bottom protective plate are typically connected by bolts or thermoplastic self-tapping screws.

[0059] Bolted connections require through holes in the bottom guard plate and cold plate. After the bolts pass through, they are secured with nuts, and sealing relies on sealant or gaskets around the through holes. However, bolted connections require standard parts such as bolts, nuts, and gaskets, resulting in high unit costs and increased overall enclosure costs. Furthermore, bolted connections involve multiple processes such as riveting and fastening, leading to lengthy assembly times. While thermoplastic self-tapping screw connections do not require pre-drilled holes, they rely on specialized tools, resulting in high costs. The thermoplastic process also has stringent requirements for process parameters (speed, pressure, feed rate), making it prone to problems such as tap breakage and plate cracking, leading to high defect rates and further increasing costs.

[0060] Therefore, the connection method between the bottom guard plate and the cold plate in the relevant technology has the problems of high cost and complex assembly process.

[0061] Furthermore, bolted connections are prone to thread loosening due to torque generated by vibration, creating micro-gaps on the sealing surface between the bottom plate and the cold plate, affecting the enclosure's airtightness. Meanwhile, heat-affected zones (HAZs) of heat-fused self-tapping screw connections experience thermal impacts on the sheet metal during the fusion process, leading to uneven plastic deformation in the connection area and disrupting the continuity of the sealant. Therefore, the heat-affected zone of heat-fused self-tapping screw connections is prone to sealant cracking, affecting the enclosure's airtightness. Thus, both bolted and heat-fused self-tapping screw connections can easily lead to airtightness failure inside and outside the battery enclosure, allowing moisture and dust to intrude, affecting battery reliability and lifespan.

[0062] Furthermore, bolted connections must ensure a clearance between the bolt head and the surface of the bottom cover plate (usually ≥5mm), and FDS connections must allow for the operating stroke of the hot melt tool (usually ≥8mm). At the same time, to avoid interference between connection points, the distance between adjacent connection points must be ≥20mm. This results in the connection area between the bottom cover plate and the cold plate requiring a large amount of space in both the direction perpendicular to and parallel to the plate surface. In other words, both bolted connections and hot melt self-tapping screw connections require reserved space for standard parts piercing and assembly operations, leading to space waste and restricting the energy density of the battery.

[0063] To address at least one of the aforementioned problems, embodiments of this application provide a battery device, a welding method, an electrical device, and an energy storage device. The battery device includes a battery cell assembly and a housing. The battery cell assembly includes at least one battery cell. The housing includes a main body and a protective component. The main body includes a bottom wall and a side wall connected to the edge of the bottom wall. The bottom wall and the side wall form a receiving area for accommodating the battery cell assembly. The protective component is disposed on the outer side of the bottom wall away from the receiving area. The bottom wall has a mounting portion, and the protective component has a mating portion. The mounting portion is interference-fitted to the mating portion. The mating portion includes multiple bosses, which protrude from the protective component along a first direction. The top surface of each boss also has at least one protrusion protruding from the top surface along the first direction. The side wall has a connecting surface facing the bottom wall, and the protrusion is welded to the connecting surface. The first direction is the direction in which the protective component faces the receiving area. Through interference-fit connection, compared to bolted connections in related technologies, standard parts such as bolts and nuts are not required, reducing costs and simplifying the assembly process. Furthermore, compared to hot-melt self-tapping screw connections, no additional hot-melt tools are needed, and strict control of hot-melt parameters is not required, further reducing costs and simplifying the assembly process. Furthermore, the interference fit connection in this embodiment eliminates the need for pre-reserved puncture space for standard parts and assembly operation space, thereby improving space utilization and ultimately increasing the energy density of the battery device. Simultaneously, the interference fit connection eliminates the need for heat fusion, making the material less prone to deformation and less likely to create gaps between the bottom wall and the protective component due to vibration, thus improving the sealing performance of the enclosure and consequently enhancing its reliability and the battery device's lifespan. Moreover, by providing protrusions on the boss, which can be welded to the connecting surfaces of the side walls, the protective component, bottom wall, and side walls can be connected together through welding. This simplifies the enclosure assembly process, eliminating the need for drilling holes in the side walls to install standard parts such as bolts, and eliminating the need for pre-riveting and assembly processes. This further reduces the number of parts, simplifies the manufacturing process, improves production efficiency, lowers costs, and also enhances the structural strength of the side walls and the enclosure.

[0064] The technical solutions described in the embodiments of this application are applicable to battery devices with protective components, electrical devices using battery devices, and energy storage devices.

[0065] The energy storage device utilizing battery devices as a power source in this application embodiment includes one or more battery clusters to enhance the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0066] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices. As an example, the energy storage device is an energy storage container or an energy storage cabinet.

[0067] In this application embodiment, the power-consuming device using a battery as a power source can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0068] It should be understood that the technical solutions described in the embodiments of this application are not limited to the energy storage devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices. However, for the sake of brevity, the following embodiments will be described using a vehicle as an example of an electrical device.

[0069] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 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 installed 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. 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, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0070] 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.

[0071] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery provided in some embodiments of this application.

[0072] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0073] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0074] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0075] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0076] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0077] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0078] As an example, the housing 20 may include a main body 400 and a protective member 500 located at the bottom of the main body 400. The protective member can protect the bottom of the main body. The main body may include a first part 21 and a second part 22. The first part 21 and the second part 22 are fastened together to form a closed space inside the housing 20 to accommodate the battery cell assembly 10. Here, "closed" refers to covering or closing, which can be a sealed closure to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The second part 22 may include a bottom wall 410 and a side wall 420 connected to the bottom wall. The bottom wall and the side wall can form a receiving area 430 to accommodate the battery cell assembly 10. The first part 21 may be a top cover connected to the side wall. The protective member 500 may be located on the bottom wall 410 away from the first part 21.

[0079] As an example, the bottom wall 410 can be a bottom plate or a heat exchanger, and the side wall 420 can be a side beam.

[0080] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0081] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0082] The battery cell 11 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0083] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. The battery cell 11 refers to the smallest unit that makes up the battery. For example... Figure 3 The battery cell 11 includes an end cap 12, a housing 13, an electrode assembly 14, and other functional components.

[0084] End cap 12 refers to a component that covers the opening of housing 13 to isolate the internal environment of battery cell 11 from the external environment. The shape of end cap 12 can be adapted to the shape of housing 13 to fit it. In some embodiments, end cap 12 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 12 is less prone to deformation under pressure and impact, enabling battery cell 11 to have higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on end cap 12. Electrode terminals can be used for electrical connection with electrode assembly 14 for outputting or inputting electrical energy to battery cell 11. In some embodiments, end cap 12 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 11 reaches a threshold. The material of end cap 12 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating element may be provided on the inner side of the end cap 12. The insulating element can be used to isolate the electrical connection components within the housing 13 from the end cap 12 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0085] The housing 13 is a component used to cooperate with the end cap 12 to form the internal environment of the battery cell 11. This internal environment can accommodate the electrode assembly 14, electrolyte, and other components. The housing 13 and the end cap 12 can be independent components. An opening can be provided on the housing 13, and the end cap 12 closes the opening to form the internal environment of the battery cell 11. Alternatively, the end cap 12 and the housing 13 can be integrated. Specifically, the end cap 12 and the housing 13 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 13, the end cap 12 closes the housing 13. The housing 13 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 13 can be determined according to the specific shape and size of the electrode assembly 14. The housing 13 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0086] Electrode assembly 14 is the component in the battery cell 11 where the electrochemical reaction takes place. The housing 13 may contain one or more electrode assemblies 14. Electrode assembly 14 is mainly formed by winding and forming positive and negative electrode plates, and a separator is typically provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly.

[0087] Figure 4 for Figure 2 Top view of the middle box; Figure 5 for Figure 4 Top view; Figure 6 for Figure 5 A partial schematic diagram of point A in the middle; Figure 7 for Figure 6 A partial schematic diagram at point B; please refer to... Figures 2 to 7 This application provides a battery device 100, including: a battery cell assembly 10 and a housing 20. The battery cell assembly 10 includes at least one battery cell 11. The housing 20 includes a main body 400 and a protective member 500. The main body 400 includes a bottom wall 410 and a side wall 420 connected to the edge of the bottom wall 410. The bottom wall 410 and the side wall 420 form a receiving area 430 for accommodating the battery cell assembly 10. The protective member 500 is disposed on the outside of the bottom wall 410 away from the receiving area 430. The bottom wall 410 is provided with a mounting part 411, and the protective member 500 is provided with a mating part 510. The mounting part 411 is interference-fitted to the mating part 510. The mating part 510 includes a plurality of bosses 511, which protrude from the protective member 500 along the first direction X. The top surface 512 of the bosses 511 is also provided with at least one protrusion 520 protruding from the top surface 512 along the first direction X. The side wall 420 has a connecting surface 421 facing the bottom wall 410, and the protrusion 520 is welded to the connecting surface 421. The first direction X is the direction in which the protective member 500 faces the receiving area 430.

[0088] In this embodiment, the main body 400 may include a bottom wall 410 and side walls 420. The bottom wall 410 may be generally plate-shaped, and the side walls 420 may be disposed along the edge of the bottom wall 410. For example, if the bottom wall is square, the side walls 420 may be disposed around its perimeter; or if the bottom wall is circular, the side walls may be disposed around its circumference. The side walls 420 may be plate-shaped or beam-shaped. The bottom wall 410 and the side walls 420 enclose a receiving area 430. The battery cell assembly 10 is received in the receiving area 430. In some embodiments, the main body 400 may also include a top wall, which may cover an opening at the top of the receiving area 430 and may be connected to the side walls to form a closed receiving area 430. The shape of the receiving area 430 may vary and can be configured according to actual conditions.

[0089] The protective component 500 can be connected to the outer side of the bottom wall 410 away from the receiving area 430, that is, the protective component 500 can cover the outside of the bottom wall 410, thereby providing protection for the bottom wall 410. The protective component 500 can be a plate-like structure, and its size can be set according to the size of the bottom wall 410 so that the protective component 500 can cover the bottom wall 410 as much as possible, thereby improving the protective effect. In addition, the protective component 500 can also strengthen the bottom wall 410, thereby improving the structural strength of the enclosure.

[0090] The connection between the protective component 500 and the bottom wall 410 can be an interference fit connection. In this embodiment, the bottom wall 410 may be provided with a mounting part 411, and the protective component 500 may be provided with a corresponding mating part 510.

[0091] It is understood that in this embodiment, the mounting part and the mating part can have various structures to achieve an interference fit. The mating part includes multiple bosses 511, which can be distributed dispersedly. Each boss 511 can protrude from the protective member along a first direction X, that is, the boss can be arranged to protrude along a direction close to the interior of the receiving area. The bosses 511 can be interference-fitted with the mounting part. For example, the mounting part can include a mounting hole 412. The size of the bosses 511 can be slightly larger than the size of the mounting hole 412, and the shape of the bosses 511 can be the same as the shape of the mounting hole 412, so that the bosses 511 can be interference-fitted into the mounting hole 412. In addition, the number of mounting holes 412 and bosses 511 can be set one-to-one or one-to-many. For example, multiple bosses 511 can be interference-fitted in one mounting hole 412.

[0092] The first direction can be perpendicular to the bottom wall and point from the protective member 500 towards the receiving area 430. It can be understood that the first direction X can be directional, and it can be... Figure 6 The direction of the arrow in the image, that is... Figure 6 The direction from bottom to top is the first direction X, while the direction from top to bottom is the opposite direction to the first direction X.

[0093] The top surface 512 of the boss 511 can be the surface of one end of the boss 511 along the protrusion direction (first direction X), or it can be the surface of the boss 511 with the largest protrusion distance compared to the protective part 500.

[0094] The top surface 512 may also have a protrusion 520 protruding along the first direction X. It is understood that the protrusion 520 can be located on the top surface of the boss 511 and protrude towards the receiving area 430, for example, it can be formed by stamping the top surface 512. The size of the protrusion 520 can be smaller than that of the top surface 512, forming a dot-like structure. During welding, this allows the current to be concentrated in the protruding area, improving welding thermal efficiency and making the weld nugget formation more stable. The shape of the protrusion 520 can be various, such as hemispherical or cylindrical, etc.

[0095] The number of protrusions 520 can be one or more. When one protrusion is provided for each boss, the protrusion 520 can be located at the center of the top surface. When multiple protrusions are provided for each boss 511, the multiple protrusions can be evenly distributed in the central area of ​​the boss 511.

[0096] The side wall 420 can be connected to the top of the bottom wall 410, that is, the side wall 420 can have a bottom surface facing the bottom wall 410, which can be a connecting surface 421, and the protrusion 520 can be welded to the connecting surface 421. Figure 4 and Figure 7 The bosses can be positioned on the side wall 420 and the bottom wall 410 respectively, meaning that the orthographic projection of each boss 511 on the plane of the bottom wall 410 can at least partially coincide with the orthographic projection of the connecting surface of the side wall 420 on the same plane. The boss 511 passes through the mounting hole 412 in the bottom wall 410, so that its top surface 512 can approach or be close to the connecting surface 421 of the side wall, and the protrusion 520 on the boss 511 can contact the connecting surface 421. Then, the protrusion 520 can be welded to the connecting surface 421 by a welding process.

[0097] In this embodiment, the mounting part is interference-fitted to the mating part, thereby connecting the bottom wall and the protective component through the interference fit. Compared with the bolt connection in related technologies, there is no need for standard parts such as bolts and nuts, which reduces costs and simplifies the assembly process. In addition, compared with the hot melt self-tapping screw connection, there is no need for additional hot melt tools or strict control of hot melt parameters, which can also reduce costs and assembly process.

[0098] In addition, the interference fit connection in this embodiment does not require reserved space for standard parts (bolts or self-tapping screws, etc.) to pierce the installation and assembly operations, which can improve space utilization and thus improve the energy density of the battery device.

[0099] Furthermore, compared to thermoplastic self-tapping screw connections, interference fit connections do not require thermoplasticizing, and the material is less prone to deformation and gaps, which helps improve the sealing performance of the enclosure. At the same time, compared to threaded connections, interference fit connections are less likely to loosen due to torque generated by vibration, thus reducing the possibility of gaps between the bottom wall and the protective components, further improving the enclosure's sealing performance, thereby increasing its reliability and the battery's lifespan. Moreover, because this embodiment improves the enclosure's sealing performance, the number of enclosures requiring rework due to airtightness issues during sealing tests is reduced, lowering rework costs.

[0100] Meanwhile, in this embodiment, by setting a protrusion on the boss, the protrusion can be welded to the connecting surface of the side wall. Since the protrusion and the mounting part of the bottom wall are interference fit, the protective part, the bottom wall and the side wall can be connected together by welding the protrusion and the connecting surface. This simplifies the assembly process of the box and eliminates the need to drill holes in the side wall to install standard parts such as bolts, as well as the need for pre-riveting, assembly and other processes. This further reduces the number of parts, simplifies the manufacturing process, improves production efficiency and reduces costs, and also improves the structural strength of the side wall and the box.

[0101] Because the protrusions are dot-shaped, their size can be small, allowing the current to be concentrated in the protruding area during welding, thus improving welding thermal efficiency. Furthermore, a continuous fusion line is formed around the weld point, resulting in a more stable weld nugget. Simultaneously, it reduces heat input to the welding area, mitigating deformation of the protective component caused by overheating.

[0102] In addition, this embodiment uses welding between the protrusion and the side wall to avoid damaging the structure of the side wall and protective components. It has good sealing performance and can effectively reduce the intrusion of corrosive media such as water vapor and salt, thereby improving the corrosion resistance and service life of the enclosure.

[0103] According to some embodiments of this application, the mounting part 411 may include a plurality of mounting holes 412 spaced apart along the edge of the bottom wall 410, and the mating part 510 includes a plurality of bosses 511 spaced apart along the edge of the protective member 500, and each boss 511 is interference-fitted into a mounting hole 412.

[0104] The mounting portion 411 may include a plurality of mounting holes 412 spaced apart along the edge of the bottom wall 410. In this embodiment, the bottom wall 410 may be rectangular, and the mounting holes 412 may be spaced apart along the long edge. In other embodiments, if the bottom wall may be of other shapes, the mounting holes 412 may also be spaced apart along other shapes. The mounting holes 412 may be square, circular, elliptical, triangular, or other shapes.

[0105] It is understandable that the multiple mounting holes 412 can be set at equal or unequal intervals, depending on the actual situation. It is also understandable that setting multiple mounting holes 412 on the edge of the bottom wall 410 can reduce the opening area of ​​the bottom wall and improve the strength of the bottom wall 410 compared to setting elongated holes.

[0106] Similarly, the edge of the protective member 500 may be provided with a plurality of protrusions 511, each protrusion 511 may protrude out of the protective member along the first direction X, that is, the protrusion may be provided in a direction close to the interior of the receiving area.

[0107] Multiple bosses 511 can correspond one-to-one with multiple mounting holes 412. Each boss can be interference-fitted into a mounting hole 412. That is, the size of the boss 511 can be slightly larger than the size of the mounting hole 412. The shape of the boss 511 can be the same as the shape of the mounting hole 412, so that the boss 511 can be interference-fitted into the mounting hole 412.

[0108] The interference fit between the boss and the mounting hole allows for a connection between the bottom wall and the protective component. This design is simple, easy to manufacture, and eliminates the need for bolts or other standard parts, thus reducing costs. Furthermore, the interference fit between the boss and the mounting hole is readily implemented, simplifying the assembly process and improving the structural strength of the bottom wall.

[0109] like Figure 7 According to some embodiments of this application, the interference amount D of the interference fit between the boss 511 and the mounting hole 412 satisfies 0.1mm≤D≤0.3mm.

[0110] It can be understood that the interference fit D refers to the dimensional difference between the boss 511 and the mounting hole 412 before assembly. Before assembly, the size of the boss 511 is larger than the size of the mounting hole 412. Taking a cylindrical boss 511 and a cylindrical mounting hole 412 as an example... Figure 7 As shown, the interference D can refer to the difference between the diameter D2 of the boss and the diameter D1 of the mounting hole 412.

[0111] In this embodiment, the interference amount D can be 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 2mm, 0.22mm, 0.24mm, 0.26mm, 0.28mm, 0.3mm, etc. In other embodiments, the interference amount D can also have different value ranges, such as 0.12mm≤D≤0.28mm, 0.1mm≤D≤0.25mm, 0.15mm≤D≤0.3mm, etc.

[0112] In this embodiment, by setting the interference fit to be no less than 0.1mm, the boss and the mounting hole can be tightly connected, improving the reliability of the connection and making it less prone to loosening. Setting the interference fit to be no more than 0.3mm can mitigate the problem of deformation or damage to one of the components during installation when the size difference between the two is too large.

[0113] Figure 8 The diagram shows welding schematics of the housing provided in some embodiments of this application. Please refer to... Figure 8 According to some embodiments of this application, the two protrusions 520 on each boss 511 are respectively the first protrusion 521 and the second protrusion 522. The first protrusion 521 is used to contact and connect with the first electrode 610 of the welding equipment 600, and the second protrusion 522 is used to contact and connect with the second electrode 620 of the welding equipment 600.

[0114] In this embodiment, the mating part 510 may include a plurality of bosses 511, and each boss may be provided with one or more protrusions 520. Among all the protrusions 520 of each boss 511, two of them are respectively designated as the first protrusion 521 and the second protrusion 522. It can be understood that when each boss 511 has multiple protrusions, the first protrusion 521 and the second protrusion 522 may be two protrusions on the same boss 511, for example, they may refer to two adjacent protrusions. Of course, they may be protrusions on two adjacent bosses.

[0115] In some embodiments, such as Figure 8As shown, each boss can be provided with a protrusion 520, with two adjacent protrusions on two adjacent bosses being the first protrusion 521 and the second protrusion 522, respectively.

[0116] The welding equipment 600 can be a common welding device, which may have a first electrode 610 and a second electrode 620. Understandably, when the welding equipment is working, one of the first electrode 610 and the second electrode 620 is connected to the positive terminal of the welding power source, and the other is connected to the negative terminal. The welding end face of the first electrode 610 (the end away from the welding power source) is in contact with the surface of the first protrusion 521 away from the connecting surface 421, and the welding end face of the second electrode 620 (the end away from the welding power source) is in contact with the surface of the second protrusion 522 away from the connecting surface 421. This can form a closed circuit loop of "welding power source - first electrode - first protrusion - housing - second protrusion - second electrode - welding power source", so that the first protrusion and the second protrusion can be welded to the connecting surface at the same time in one welding operation.

[0117] The first electrode and the second electrode can be two flat electrodes with the same structure. The axis of each electrode can coincide with the center line of the corresponding protrusion, thereby improving the welding quality.

[0118] The above explanation uses the example of two adjacent protrusions on two adjacent bosses as an example. In other embodiments, depending on the number of protrusions on the bosses, the first and second protrusions can also be two protrusions on the same boss, etc., which can be set according to the actual situation. It can be understood that the first and second protrusions are usually selected from the protrusions that have not been welded and are close to each other or adjacent to each other, so as to reduce the current path, reduce losses, and improve the welding quality.

[0119] Understandably, in related technologies, welding a protrusion to a connecting surface requires two electrodes to be positioned opposite each other, one in contact with the protrusion and the other with the back of the connecting surface. This means two electrodes are positioned on opposite sides of the first direction, with their axes aligned, thus connecting the protrusion to the connecting surface. However, placing the electrode on the back of the connecting surface imposes limitations on the sidewall structure; for sidewalls with shapes such as beams, electrode placement is difficult.

[0120] In this embodiment, by contacting the first electrode with the first protrusion and the second electrode with the second protrusion, a single-sided double-spot welding method can be used on one side of the protective component to form a closed circuit loop using two symmetrical electrodes. This results in a short and stable welding current path. Furthermore, compared to welding methods in related technologies, both protrusions can be welded to the connection surface simultaneously, improving welding efficiency.

[0121] Meanwhile, because the protrusion size can be relatively small, the current can be concentrated in the protruding area during welding, improving welding thermal efficiency and forming a continuous fusion line around the weld point, resulting in a more stable weld nugget. It also reduces the heat input to the welding area, mitigating deformation of the protective component caused by overheating.

[0122] Furthermore, this embodiment eliminates the need for a back electrode support, improving upon related technologies where welding methods suffer from issues such as weld point misalignment and incomplete welds due to back electrode positioning deviations on the connection surface. This significantly reduces the welding defect rate and improves welding quality. Moreover, the elimination of the need for electrodes on the back of the connection surface allows for electrode arrangement without being limited by the housing structure, making it more flexible in use.

[0123] According to some embodiments of this application, a first adhesive layer 422 is further provided between the connecting surface 421 and the bottom wall 410, and between the connecting surface 421 and the boss 511.

[0124] The first adhesive layer 422 can be a spot welding sealant, which can be applied to the surface of the connecting surface 421, thereby forming a sealant layer between the connecting surface 421 and the boss 511 and between the connecting surface 421 and the bottom wall 410 after the protrusion welding.

[0125] It is understood that the first adhesive layer 422 can cover the top surface 512 of the boss (excluding the welded area) and the portion of the side surface of the boss protruding from the bottom wall 410, thereby improving the connection strength between the boss and the side wall. Additionally, the first adhesive layer 422 can also be located between the bottom wall and the connecting surface 421, thereby improving the connection strength between the bottom wall and the side wall.

[0126] In this embodiment, the first adhesive layer can improve the connection strength between the boss and the sidewall, as well as between the bottom wall and the sidewall, and can also play a sealing role, improving the corrosion failure caused by water vapor and other substances entering the connection gap between the bottom wall and the sidewall.

[0127] According to some embodiments of this application, the protrusion 520, the boss 511, and the protective component 500 are integrally formed.

[0128] In this embodiment, the protrusion 520, the boss 511, and the protective component 500 can be integrally formed into a single part, for example, by casting or stamping.

[0129] In some embodiments, the protrusions, bosses, and protective elements can be made of the same material, such as steel or aluminum plates, and formed by a single stamping process, thereby simplifying the processing technology and improving processing efficiency.

[0130] In other embodiments, the boss can be integrally formed with the protective component, and the protrusion can be processed onto the boss using other processes, which can also improve processing efficiency.

[0131] By using a one-piece molded protective component, secondary splicing is eliminated during processing, saving mold development costs and reducing processing costs. Furthermore, the resulting protective component has no splicing welds, exhibiting excellent structural integrity. This significantly improves the fatigue strength and impact resistance of the protective component and the boss, while simplifying processing steps and reducing the risk of seal failure caused by splicing.

[0132] According to some embodiments of this application, a second adhesive layer 530 is provided between the protective member 500 and the bottom wall 410, and a portion of the second adhesive layer 530 is located between the mounting portion 411 and the mating portion 510.

[0133] A second adhesive layer 530 is provided between the protective component 500 and the bottom wall. The second adhesive layer 530 can be a structural adhesive, such as an anaerobic sealant.

[0134] It is understandable that during the assembly of the mounting part and the mating part, such as when the boss is pressed into the mounting hole, the adhesive that constitutes the second adhesive layer can be squeezed and filled into the microscopic gap between the protective part and the bottom wall, further improving the connection strength between the protective part and the bottom wall. At the same time, it can also play a sealing role and improve problems such as sealing failure.

[0135] In addition, during assembly, some adhesive can be squeezed into the space between the side surface of the boss and the inner surface of the mounting hole. While the boss and the mounting hole are connected by an interference fit, the adhesive acts as a bond, further improving the bonding strength between the boss and the mounting hole.

[0136] like Figure 4 As shown, the second adhesive layer can be provided not only between the edge of the bottom wall (the edge area with the protrusion) and the protective member 500, but also between the entire surface of the bottom wall and the protective member. That is, the area where the reinforcing part 540 is provided can also be provided with the second adhesive layer, so that the two are seamlessly connected and the sealing performance is improved.

[0137] In this embodiment, by providing a second adhesive layer between the bottom wall and the protective component, the bottom wall and the protective component can be connected through both interference fit and adhesive bonding, thereby improving the connection strength between them. Furthermore, since the second adhesive layer can fill the space between the bottom wall and the protective component, and can be located between the boss and the mounting hole, it achieves a dual sealing structure of mechanical interlocking and adhesive sealing while simultaneously providing a seal through the interference fit. This further enhances the sealing effect. Compared to a single sealing method, it improves sealing reliability and addresses the problem of poor airtightness of the enclosure in related technologies.

[0138] According to some embodiments of this application, the bottom wall 410 includes a heat exchange element 413, a side wall 420 is connected to the edge of the heat exchange element 413, the heat exchange element 413 has a channel for the flow of heat exchanger, and the heat exchange element 413 is thermally connected to the battery cell assembly 10.

[0139] In this embodiment, the heat exchanger 413 can be generally plate-shaped, and it can have channels inside. The channels can have inlets and outlets, and heat exchanger can flow in the channels, so that the heat exchanger 413 can exchange heat with the battery cell assembly 10, for example, to cool the battery cell assembly 10.

[0140] The structure of the heat exchanger 413 can be varied. For example, the heat exchanger can be composed of a flow channel plate and a cover plate. The flow channel plate can be formed into a curved and meandering flow channel by stamping or other methods, and the cover plate can be placed on the flow channel plate, forming a channel between the two. It can be understood that the part of the heat exchanger 413 located at the position corresponding to the receiving area 430, that is, at the connection position of the side wall, bottom wall and boss, may not have a channel, thereby facilitating the assembly of the housing.

[0141] In addition, the installation section can avoid the inlet and outlet positions of the channel, so that the heat exchanger can circulate through the inlet and outlet.

[0142] In this embodiment, using a heat exchanger as the bottom wall of the housing simplifies the housing structure while allowing for cooling and heat exchange of the individual battery cells. The protective component safeguards the heat exchanger, mitigating issues such as breakage due to impacts.

[0143] According to some embodiments of this application, the sidewall 420 includes a side beam 423 having an internal cavity, the side beam 423 having a connecting surface 421 facing the bottom wall 410, the connecting surface 421 being connected to the bottom wall 410.

[0144] In this embodiment, the side wall 420 can be a side beam 423 with an internal cavity. It can be understood that the side beam 423 can have an internal cavity, that is, a hollow cavity.

[0145] The cavity may have one or more partitions to divide it into multiple spaces, thereby improving the structural strength of the side beam. The side beam 423 can be manufactured by extrusion, casting, or other methods.

[0146] It is understood that in this embodiment, the sidewall 420 may include side beams surrounding the battery cell assembly, that is, the four side beams 423 may form a cuboid space. Of course, in other embodiments, the side beams may also form other shapes.

[0147] The bottom surface of the side beam 423 can be connected to the top surface of the bottom wall, meaning the connecting surface of the side beam 423 facing the bottom wall can be connected to the bottom wall. This connection can be direct, indirect, or a combination of both. For example, the side beam and bottom wall can be indirectly connected by welding the protrusion of the protective component to the connecting surface, or by an interference fit between the protrusion and the mounting hole. Alternatively, the side beam can also be directly connected to the bottom wall via the first adhesive layer 422.

[0148] In this embodiment, by setting side beams with cavities inside, the strength of the box and its anti-collision and buffering performance can be improved. In addition, the side beams can also provide a larger connection surface to facilitate welding with protrusions and increase the area of ​​the first adhesive layer, thereby further improving the connection strength between the side beams and the bottom wall and the protective components, and thus enhancing the structural strength of the box.

[0149] According to some embodiments of this application, the protective member 500 is provided with at least one reinforcing portion 540 protruding in a direction away from the receiving area 430.

[0150] In this embodiment, the reinforcing part can be a protruding structure provided on the protective member, thereby making the protective member form an uneven surface to improve its structural strength.

[0151] In addition, the reinforcing part can protrude in a direction away from the receiving area 430, which eliminates the need to reserve space for the reinforcing part between the bottom wall and the protective component, thereby reducing the installation gap between the bottom wall and the protective component and improving airtightness.

[0152] The number of reinforcing parts 540 can be one or more, and their shapes can also be various, for example... Figure 4 The various structures shown, such as rectangles, crosses, and T-shapes, can be configured according to actual needs. In some embodiments, the reinforcing part can also be integrally formed with the boss through processes such as stamping, thereby simplifying the process steps and improving production efficiency.

[0153] This embodiment improves the structural strength of the protective component by adding a reinforcing part, thereby enhancing its protective effect on the bottom wall. The reinforcing part can protrude in a direction away from the receiving area, eliminating the need for pre-reserved space between the bottom wall and the protective component, thus reducing installation gaps between the bottom wall and the protective component and improving airtightness.

[0154] Figure 9 This is a schematic flowchart illustrating the welding method provided in some embodiments of this application. Please refer to... Figures 8 to 9This application embodiment also provides a welding method 700 for the battery device 100 in any of the above embodiments. The bottom wall of the battery device 100 is provided with a plurality of mounting holes 412. The protective member of the battery device 100 is provided with a plurality of bosses 511 protruding from the protective member 500 along a first direction X. Each boss 511 is interference-fitted into a mounting hole 412. The top surface 512 of the boss 511 is also provided with at least one protrusion 520 protruding from the top surface 512 along the first direction X, wherein the first direction X is the direction of the protective member 500 facing the receiving area 430 of the battery device 100. The method 700 includes steps S710 to S720.

[0155] In step S710, the first electrode 610 of the welding equipment 600 is brought into contact with the first protrusion 521, and the second electrode 620 of the welding equipment 600 is brought into contact with the second protrusion 522. The first protrusion 521 and the second protrusion 522 are two protrusions 520 on each boss 511. The first electrode 610 and the second electrode 620 are located on the same side of the protective member 500 away from the receiving area 430.

[0156] In step S720, power is supplied to the first electrode 610 and the second electrode 620 to weld the first protrusion 521 and the second protrusion 522 to the connecting surface 421, wherein the connecting surface 421 is the surface of the side wall 420 of the battery device 100 facing the bottom wall 410.

[0157] In this embodiment, the bottom wall 410 may be provided with a mating part 510, which may include a plurality of bosses 511. Each boss may be provided with one or more protrusions 520. Among all the protrusions 520 of each boss 511, two of them are respectively designated as the first protrusion 521 and the second protrusion 522. It can be understood that when each boss 511 has multiple protrusions, the first protrusion 521 and the second protrusion 522 may be two protrusions on the same boss 511, such as two adjacent protrusions. Of course, they may be protrusions on two adjacent bosses.

[0158] In some embodiments, such as Figure 8 As shown, each boss can be provided with a protrusion 520, with two adjacent protrusions on two adjacent bosses being the first protrusion 521 and the second protrusion 522, respectively.

[0159] The welding equipment 600 can be a common welding device, which may have a first electrode 610 and a second electrode 620. It can be understood that when the welding equipment is working, one of the first electrode 610 and the second electrode 620 is connected to the positive terminal of the welding power source, and the other is connected to the negative terminal. In step S710, the welding end face (the end away from the welding power source) of the first electrode 610 is brought into contact with the surface of the first protrusion 521 away from the connecting surface 421, and the welding end face (the end away from the welding power source) of the second electrode 620 is brought into contact with the surface of the second protrusion 522 away from the connecting surface 421.

[0160] Step S720 can turn on the welding power supply, thereby supplying power to the first electrode and the second electrode, and forming a closed circuit loop of "welding power supply - first electrode - first protrusion - housing - second protrusion - second electrode - welding power supply", so that the first protrusion and the second protrusion can be welded to the connection surface at the same time.

[0161] The above explanation uses the example of two adjacent protrusions on two adjacent bosses as an example. In other embodiments, depending on the number of protrusions on the bosses, the first and second protrusions can also be two protrusions on the same boss, etc., which can be set according to the actual situation. It can be understood that the first and second protrusions are usually selected from the protrusions that have not been welded and are close to each other or adjacent to each other, so as to reduce the current path, reduce losses, and improve the welding quality.

[0162] In addition, the protective components, bottom wall, side wall, boss, mounting hole, protrusion, and other structures and functions in this embodiment are the same as those in the above embodiments. For details, please refer to the above embodiments, and they will not be repeated here.

[0163] In this embodiment, by contacting the first electrode with the first protrusion and the second electrode with the second protrusion, a single-sided double-spot welding method can be used on one side of the protective component to form a closed circuit loop with two symmetrical electrodes, achieving rapid welding of the enclosure. The welding current path is short and stable. Compared with welding methods in related technologies, it can weld two protrusions to the connection surface simultaneously, improving welding efficiency.

[0164] Meanwhile, because the protrusions are dot-shaped, their size can be small, allowing the current to be concentrated in the protruding area during welding, improving welding thermal efficiency. Furthermore, a continuous fusion line is formed around the weld point, resulting in a more stable weld nugget. This also reduces heat input to the welding area, mitigating deformation of the protective component caused by overheating.

[0165] Furthermore, this embodiment eliminates the need for a back electrode support, improving upon related technologies where welding methods suffer from issues such as weld point misalignment and incomplete welds due to back electrode positioning deviations on the connection surface. This significantly reduces the welding defect rate and improves welding quality. Moreover, the elimination of the need for electrodes on the back of the connection surface allows for electrode arrangement without being limited by the housing structure, making it more flexible in use.

[0166] In addition, this embodiment uses welding between the protrusion and the side wall connection surface. Compared with the box connection method of standard parts such as bolts in related technologies, it will not damage the structure of the side wall and protective parts. It has good sealing performance and can effectively reduce the intrusion of corrosive media such as water vapor and salt, thereby improving the corrosion resistance and service life of the box. At the same time, there is no need to open holes in the side wall to install standard parts such as bolts, nor is it necessary to perform pre-riveting, assembly and other processes, which simplifies the manufacturing process and improves production efficiency.

[0167] According to some embodiments of this application, the axis of the first electrode 610 coincides with the center line of the first protrusion 521, and the axis of the second electrode 620 coincides with the center line of the second protrusion 522; and the first electrode 610 and the second electrode 620 have the same size.

[0168] The first electrode and the second electrode can be two electrodes with identical structural dimensions, such as flat electrodes. A flat electrode is an electrode whose working surface in contact with the workpiece is a flat or slightly convex spherical surface. Flat electrodes have a large contact area, are less prone to indentation, and provide better protection for the workpiece. The first electrode 610 can coincide with the centerline of the first protrusion 521; for example, it can be located at... Figure 8 The second electrode 620 is located directly above and in contact with the first protrusion 521. The second electrode 620 may coincide with the centerline of the second protrusion 522; for example, it may be located at... Figure 8 It is located directly above and in contact with the second protrusion 522. That is, the axis of each electrode can coincide with the center line of the corresponding protrusion, and the two electrodes can be located on the same side.

[0169] In this embodiment, by aligning the axis of the first electrode with the center line of the first protrusion and aligning the axis of the second electrode with the center line of the second protrusion, the current and pressure can be uniformly concentrated on the protrusion, which is beneficial to forming a high-quality, high-strength weld nugget.

[0170] This application provides an electrical device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0171] Electrical devices include vehicles (such as cars, electric vehicles, ships, spacecraft, etc.), display devices (such as mobile phones, tablets, laptops, etc.), electric toys, power tools, etc.

[0172] It is understood that the electrical device provided in this application, by using any of the aforementioned battery devices 100, has all the beneficial effects of the aforementioned battery devices 100, which will not be elaborated here.

[0173] This application provides an energy storage device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to store electrical energy.

[0174] Energy storage devices can include, but are not limited to, centralized energy storage devices (such as containerized energy storage devices), distributed energy storage devices, mobile energy storage devices, wearable energy storage devices, and so on.

[0175] It is understood that the energy storage device provided in this application, by using any of the aforementioned battery devices 100, has all the beneficial effects of the aforementioned battery devices 100, which will not be elaborated here.

[0176] Please refer to Figures 2 to 8 This application provides a battery device 100, including: a battery cell assembly 10 and a housing 20. The battery cell assembly 10 includes at least one battery cell 11. The housing 20 includes a main body 400 and a protective member 500. The main body 400 includes a bottom wall 410 and a side wall 420 connected to the edge of the bottom wall 410. The bottom wall 410 and the side wall 420 form a receiving area 430 for accommodating the battery cell assembly 10. The protective member 500 is disposed on the outer side of the bottom wall 410 away from the receiving area 430. The bottom wall 410 is provided with a mounting portion 411, and the protective member 500 is provided with a mating portion 510. The mounting portion 411 may include a plurality of mounting holes 412 spaced apart along the edge of the bottom wall 410, and the mating portion 510 includes a plurality of bosses 511 spaced apart along the edge of the protective member 500. The bosses 511 protrude from the protective member 500 along a first direction X, and each boss 511 is interference-fitted into a mounting hole 412. The first direction X is the direction in which the protective member 500 faces the receiving area 430.

[0177] In this embodiment, the boss is interference-fitted to the mounting hole, thereby connecting the bottom wall and the protective component through interference fit. Compared with bolt connection in related technologies, it does not require standard parts such as bolts and nuts, reducing costs and simplifying the assembly process. In addition, compared with hot melt self-tapping screw connection, it does not require additional hot melt tools or strict control of hot melt parameters, which can also reduce costs and assembly process.

[0178] In addition, the interference fit connection in this embodiment does not require reserved space for standard parts (bolts or self-tapping screws, etc.) to pierce the installation and assembly operations, which can improve space utilization and thus improve the energy density of the battery device.

[0179] Furthermore, compared to thermoplastic self-tapping screw connections, interference fit connections do not require thermoplasticizing, and the material is less prone to deformation and gaps, which helps improve the sealing performance of the enclosure. At the same time, compared to threaded connections, interference fit connections are less likely to loosen due to torque generated by vibration, thus reducing the possibility of gaps between the bottom wall and the protective components, further improving the enclosure's sealing performance, thereby increasing its reliability and the battery's lifespan. Moreover, because this embodiment improves the enclosure's sealing performance, the number of enclosures requiring rework due to airtightness issues during sealing tests is reduced, lowering rework costs.

[0180] The top surface 512 of the boss 511 is also provided with at least one protrusion 520 protruding from the top surface 512 along the first direction X, and the side wall 420 has a connecting surface 421 facing the bottom wall 410, and the protrusion 520 is welded to the connecting surface 421.

[0181] In this embodiment, by setting a protrusion on the boss, the protrusion can be welded to the connecting surface of the side wall. Since the protrusion is interference-fitted with the mounting hole of the bottom wall, the protective component, the bottom wall and the side wall can be connected together by welding the protrusion and the connecting surface. This simplifies the assembly process of the box and eliminates the need to drill holes in the side wall to install standard parts such as bolts, as well as the need for pre-riveting, assembly and other processes. This further reduces the number of parts, simplifies the manufacturing process, improves production efficiency and reduces costs, and also improves the structural strength of the side wall and the box.

[0182] Because the protrusions are dot-shaped, their size can be small, allowing the current to be concentrated in the protruding area during welding, thus improving welding thermal efficiency. Furthermore, a continuous fusion line is formed around the weld point, resulting in a more stable weld nugget. Simultaneously, it reduces heat input to the welding area, mitigating deformation of the protective component caused by overheating.

[0183] In addition, this embodiment uses welding between the protrusion and the side wall to avoid damaging the structure of the side wall and protective components. It has good sealing performance and can effectively reduce the intrusion of corrosive media such as water vapor and salt, thereby improving the corrosion resistance and service life of the enclosure.

[0184] 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 therein. 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 device, characterized in that, include: A battery cell assembly, the battery cell assembly comprising at least one battery cell; The housing includes a main body and a protective component. The main body includes a bottom wall and a side wall connected to the edge of the bottom wall. The bottom wall and the side wall form a receiving area for accommodating the battery cell assembly. The protective component is disposed on the outside of the bottom wall away from the receiving area. The bottom wall is provided with a mounting part, and the protective component is provided with a mating part. The mounting part is interference-fitted to the mating part. The mating part includes a plurality of bosses, which protrude from the protective member along a first direction. The top surface of each boss is also provided with at least one protrusion protruding from the top surface along the first direction. The side wall has a connecting surface facing the bottom wall, and the protrusion is welded to the connecting surface. The first direction is the direction in which the protective member faces the receiving area.

2. The battery device according to claim 1, characterized in that, The mounting portion includes a plurality of mounting holes spaced apart along the edge of the bottom wall, and the mating portion includes a plurality of bosses spaced apart along the edge of the protective member, with each boss being interference-fitted into one of the mounting holes.

3. The battery device according to claim 2, characterized in that, The interference D of the interference fit between the boss and the mounting hole satisfies 0.1mm≤D≤0.3mm.

4. The battery device according to claim 1, characterized in that, The two protrusions on each of the protrusions are respectively a first protrusion and a second protrusion. The first protrusion is used to contact and connect with the first electrode of the welding equipment, and the second protrusion is used to contact and connect with the second electrode of the welding equipment.

5. The battery device according to claim 1, characterized in that, A first adhesive layer is also provided between the connecting surface and the bottom wall, and between the connecting surface and the boss.

6. The battery device according to claim 1, characterized in that, The protrusion, the boss, and the protective component are integrally formed.

7. The battery device according to any one of claims 1-6, characterized in that, A second adhesive layer is provided between the protective component and the bottom wall, and a portion of the second adhesive layer is located between the mounting portion and the mating portion.

8. The battery device according to any one of claims 1-6, characterized in that, The bottom wall includes a heat exchanger, the side wall is connected to the edge of the heat exchanger, the heat exchanger has a channel inside for the flow of heat exchange fluid, and the heat exchanger is thermally connected to the battery cell assembly.

9. The battery device according to any one of claims 1-6, characterized in that, The sidewall includes a side beam with an internal cavity, the side beam having a connecting surface facing the bottom wall, the connecting surface being connected to the bottom wall.

10. The battery device according to any one of claims 1-6, characterized in that, The protective component is provided with at least one reinforcing part that protrudes in a direction away from the receiving area.

11. A welding method, characterized in that, For a battery device according to any one of claims 1-10, the mounting portion of the battery device includes a plurality of mounting holes spaced apart along the edge of the bottom wall of the battery device, and a protective member of the battery device is provided with a plurality of bosses protruding from the protective member in a first direction, each boss being interference-fitted into one of the mounting holes; and the top surface of each boss is further provided with at least one protrusion protruding from the top surface in the first direction, wherein the first direction is the direction in which the protective member faces the receiving area of ​​the battery device; the method includes: The first electrode of the welding equipment is brought into contact with the first protrusion, and the second electrode of the welding equipment is brought into contact with the second protrusion, wherein the first protrusion and the second protrusion are two protrusions on each of the protrusions, and the first electrode and the second electrode are located on the same side of the protective member away from the receiving area; Power is supplied to the first electrode and the second electrode to weld the first protrusion and the second protrusion to the connecting surface, wherein the connecting surface is the sidewall surface of the battery device facing the bottom wall.

12. The method according to claim 11, characterized in that, The axis of the first electrode coincides with the center line of the first protrusion, and the axis of the second electrode coincides with the center line of the second protrusion; Furthermore, the first electrode and the second electrode are the same size.

13. An electrical appliance, characterized in that, The electrical device includes a battery device as described in any one of claims 1-10, the battery device being used to provide electrical energy.

14. An energy storage device, characterized in that, The energy storage device includes a battery device as described in any one of claims 1-10, the battery device being used to store electrical energy.

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