Battery monomer, battery device, electric equipment and energy storage device

Abstract

The utility model provides a battery monomer, a battery device, electric equipment and an energy storage device, and belongs to the field of batteries. The single battery comprises an electrode assembly and a shell, the shell is provided with a containing cavity with an opening in one end, and the containing cavity is used for containing the electrode assembly; one part of the shell side wall of the shell is a laminated structure component, the other part of the shell side wall of the shell is a fully-dense metal component, the laminated structure component and the fully-dense metal component are sequentially distributed in the axial direction of the electrode assembly, and the laminated structure component is provided with an inner layer, a foam metal layer and an outer layer which are sequentially connected from the inner side of the containing cavity to the outer side of the containing cavity; and the inner layer and the outer layer are fully-dense metal layers. A part of the shell side wall of the shell is designed to be provided with the foam metal layer, the foam metal layer can maintain certain structural rigidity, and the foam metal layer can effectively absorb impact energy and reduce weight due to the porous characteristic of the foam metal layer, so that the weight and the structural strength of the shell are well balanced, and the service life of the shell is prolonged. And the light weight of the shell and the improvement of the energy density of the battery monomer are both facilitated.

Description

Technical Field

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

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

[0003] The reliability and safety of a single battery cell are related to the structural strength of its casing. To ensure good safety performance, the casing of a battery cell should possess high structural strength, making it resistant to deformation under impact and collision. Balancing lightweight casing and increased energy density while meeting certain impact resistance requirements is a crucial issue. Utility Model Content

[0004] This application aims to at least solve one of the technical problems existing in the background art. To this end, one object of this application is to provide a battery cell, battery device, electrical device, and energy storage device that can simultaneously achieve lightweight casing and improved energy density of the battery cell.

[0005] An embodiment of the first aspect of this application provides a battery cell, including: an electrode assembly and a housing, the housing having a receiving cavity with one end open for accommodating the electrode assembly; a portion of the sidewall of the housing is a laminated structure component and the remaining portion is a fully dense metal component, the laminated structure component and the fully dense metal component are sequentially distributed along the axial direction of the electrode assembly, the laminated structure component is configured to have a connected inner layer, a foamed metal layer and an outer layer sequentially from the inner side to the outer side of the receiving cavity, the inner layer and the outer layer are both fully dense metal layers.

[0006] In this embodiment, the battery cell features a casing with interconnected inner, foamed metal, and outer layers arranged sequentially from the inside to the outside of the receiving cavity on a portion of its sidewall. The inner and outer layers are fully dense metal layers, while the foamed metal layer maintains structural rigidity and, due to its porous nature, effectively absorbs impact energy and reduces weight. Compared to casings made entirely of dense metal or plastic, this embodiment achieves lightweight design without sacrificing excessive thickness to maintain necessary structural strength for impact resistance. In other words, the casing achieves a good balance between weight and structural strength, balancing lightweight design with increased energy density in the battery cell.

[0007] In some embodiments, the shell sidewall of the housing includes a first portion and a second portion, which are adjacent to and connected along the axial direction of the electrode assembly. The first portion forms an opening around the opening. The first portion is a fully dense metal component, and the second portion is a laminated structure component. The battery cell also includes an end cap connected to the first portion and used to close the opening.

[0008] Under the condition that the shell can meet the impact resistance performance, it can not only take into account the lightweight shell and the improvement of the energy density of the battery cells, but also the shell opening end face is smooth and dense. This can prevent the possibility of dust and other impurities and moisture from the external environment entering from the top surface of the shell and remaining in the foam metal layer. This reduces the possibility that the electrode components in the cavity will be affected by the impurities and moisture remaining in the foam metal layer, thus reducing the safety performance.

[0009] In some embodiments, the inner layer of the second part, the outer layer of the second part, and the first part are fixedly connected and together enclose to form a groove, and the end of the groove facing away from the first part has an opening; the opening is used to allow the foam metal block to pass through, and the groove is used to accommodate the foam metal block and allow the foam metal block to foam to form a foam metal layer.

[0010] In this embodiment, the foam metal layer is formed directly by foaming a foam metal block placed in the groove. The surface of the foam metal layer is tightly connected to the groove wall, which has a positive effect on improving the structural strength of the shell sidewall.

[0011] In some embodiments, the thickness of the shell sidewalls is uniform and T, where T satisfies: T≥10mm.

[0012] This embodiment adopts this design, which, for relatively thick shell sidewalls, directly foams the metal foam layer into the groove, which helps to improve the structural strength of the shell sidewalls and enables the shell sidewalls to meet the impact resistance requirements.

[0013] In some embodiments, the inner layer of the second part, the outer layer of the second part, and the first part are fixedly connected and together enclose to form a groove, and the end of the groove facing away from the first part has an opening; the opening allows the foam metal layer to pass through, and the foam metal layer is inserted into the groove.

[0014] In this embodiment, the foam metal layer is pre-formed and then inserted into the groove, so that the preparation of the foam metal layer and the preparation of the pre-assembled parts can be carried out simultaneously as two independent processes on the battery production line, which can significantly improve the preparation efficiency of the casing.

[0015] In some embodiments, the first part and the second part are assembled together. This embodiment involves molding the first part and the second part separately before assembling them, which allows for the independent and simultaneous production of the first part and the second part, facilitating modular manufacturing.

[0016] In some embodiments, the foam metal layer is bonded to the inner and outer layers. This further improves the reliability of the connection between the foam metal layer and the inner and outer layers, thereby contributing to a further improvement in the connection reliability and structural strength of the second part.

[0017] In some embodiments, the thickness of the shell sidewalls is equal everywhere and is T, where T satisfies: 0 mm < T < 10 mm.

[0018] For relatively thin shell sidewalls, bonding pre-formed foam metal layers can reduce the possibility of uneven foam metal layer thickness and poor bonding due to limited foaming space during the foaming process.

[0019] In some embodiments, the inner layer and outer layer of the second part are integrally formed with the first part. On the one hand, this eliminates the assembly process between the inner and outer layers of the second part and the first part, which helps improve the manufacturing efficiency of the shell sidewall. On the other hand, it can effectively improve the structural strength of the shell sidewall without increasing costs.

[0020] In some embodiments, the end cap is welded to the first portion to form a welded portion, and the welded portion has a weld depth on the first portion that is less than the height of the first portion in the axial direction of the electrode assembly.

[0021] This embodiment welds the end cap to the first part, making the connection between the end cap and the housing reliable. Furthermore, it prevents the welded portion from extending into the second part in the axial direction of the electrode assembly. This reduces the possibility of thermal damage to the foam metal layer caused by the high temperature generated during welding, which could lead to the collapse of the pores in the foam metal layer. This effectively protects the lightweight, energy absorption, and heat insulation properties of the foam metal layer.

[0022] In some embodiments, the thickness of the shell sidewall is uniform and T everywhere, and the ratio of the thickness t of the foam metal layer to the thickness T of the shell sidewall satisfies: 0.33≤t / T≤0.5.

[0023] In this embodiment, the thickness t of the foam metal layer does not exceed half of the thickness T of the shell sidewall, so that the weight of the shell sidewall is reduced as much as possible, while the shell sidewall can maintain a certain structural strength to meet the impact resistance requirements.

[0024] In some embodiments, the porosity of the foamed metal layer is greater than 80%. This embodiment achieves a higher porosity in the foamed metal layer, resulting in a significantly lower weight than a fully dense metal layer while maintaining the same volume, thereby effectively reducing the weight of the casing.

[0025] An embodiment of the second aspect of this application provides a battery device that includes the battery cell described in the above embodiments.

[0026] An embodiment of the third aspect of this application provides an electrical device that includes a single battery cell as described in the above embodiments, or that includes a battery device as described in the above embodiments.

[0027] An embodiment of the fourth aspect of this application provides an energy storage device that includes a single battery cell as described in the above embodiments, or that includes a battery device as described in the above embodiments.

[0028] 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

[0029] 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.

[0030] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0031] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0032] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0033] Figure 4 This is a cross-sectional schematic diagram of the sidewall of the housing of a battery cell according to some embodiments of this application;

[0034] Figure 5 This is a cross-sectional schematic diagram of the sidewall of the housing of a battery cell according to other embodiments of this application;

[0035] Figure 6 This is an assembly diagram of the sidewall of the housing of a battery cell according to some embodiments of this application;

[0036] Figure 7 This is a partial cross-sectional schematic diagram of the battery cell housing and end cap in some embodiments of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1000 vehicles;

[0039] Battery unit 100, controller 200, motor 300;

[0040] Battery cell assembly 10, battery cell 11, housing 110, first part 110a, second part 110b, third part 110c, inner layer 111, foam metal layer 112, outer layer 113, groove 114, electrode assembly 120, end cap 130, welded part 140.

[0041] Box 20, first box 21, second box 22. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0047] 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).

[0048] 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.

[0049] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation", "connection", "linking", 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 connection of two components or the interaction between two components.

[0050] In this application, the term "parallel" includes not only absolute parallelism but also approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only absolute perpendicularity but also approximate perpendicularity as commonly understood in engineering. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0051] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used 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 power battery applications, market demand is also constantly increasing.

[0052] To ensure good vibration and impact resistance, the battery cell casing must possess a certain degree of rigidity. Existing battery cell casings are typically made of steel or aluminum. When the entire casing is made of pure aluminum or pure steel, the casing thickness should fall within the range of [x mm, y mm], where x and y > 0, to meet impact resistance requirements and achieve the necessary structural strength. It is understandable that, without changing other dimensional parameters, the casing thickness affects the volume of the internal cavity, thus impacting the energy density of the battery cell. Therefore, a minimum limit value of x mm is often chosen for the casing thickness.

[0053] To improve the performance of electric vehicles such as electric bicycles, electric motorcycles, and electric cars, battery devices are increasingly trending towards lightweight design. Building upon the preceding descriptions, those skilled in the art might consider reducing the casing thickness to decrease weight in order to achieve a thinner casing. However, this approach would result in insufficient structural strength, failing to meet impact resistance requirements. Alternatively, those skilled in the art might consider using plastics or other polymer materials to fabricate the casing for weight reduction; however, in this case, to ensure the casing meets impact resistance requirements, its thickness needs to be significantly increased. Without changing other dimensional parameters, the volume of the internal cavity within the casing decreases, leading to a reduction in the energy density of the individual battery cells.

[0054] In summary, using pure aluminum or pure steel for the casing results in a thinner casing and higher energy density, but also a heavier weight; using plastic casing results in a lighter weight, but a thicker casing and lower energy density. It is evident that achieving both thinner and lighter casings is difficult under the same structural strength requirements. Furthermore, with other parameters remaining constant, there is a constraint between increasing casing thickness and improving battery energy density; therefore, it is difficult to simultaneously achieve both high energy density in individual battery cells and lightweight casings.

[0055] Based on the above considerations, a battery cell was designed by using a stacked structure for part of the shell sidewalls. This stacked structure consists of an inner layer, a foamed metal layer, and an outer layer, sequentially arranged from the inside to the outside of the receiving cavity. The inner layer, outer layer, and the remaining shell sidewalls are all made of fully dense metal material. This results in a composite structure where a portion of the shell sidewalls is composed of two fully dense metal layers and a foamed metal layer between them. Compared to a cell made entirely of fully dense metal material, this design effectively replaces the fully dense metal sidewalls with foamed metal layers, achieving both lightweight construction and high structural strength. Therefore, this battery cell mitigates the conflict between shell weight and shell thickness, thus achieving a balance between lightweight shell and increased energy density of the battery cell.

[0056] The battery devices described in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft, as well as in energy storage devices. A power system for such electrical equipment can be constructed using battery cells and battery devices as described in this application. Similarly, a power system for such energy storage devices can be constructed using battery cells and battery devices as described in this application.

[0057] The energy storage device utilizing a battery as a power system in this application embodiment can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems, etc. The energy storage device can store electrical energy as needed and output it at appropriate times. For example, the energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. The energy storage device provided in this application embodiment can be used in any power system that requires energy storage.

[0058] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0059] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed within the cabinet. Each battery cluster may include multiple battery units connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, these clusters are connected in parallel to increase the capacity of the energy storage device.

[0060] In this application embodiment, the electrical devices using battery devices as power sources can be, but are 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.

[0061] It should be understood that the technical solutions described in the embodiments of this application are not limited to the battery devices and electrical equipment described above, but can also be applied to all battery devices including housings and electrical equipment using battery devices. However, for the sake of brevity, the following embodiments are all illustrated using electric vehicles as examples.

[0062] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. 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.

[0063] 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.

[0064] Figure 2 A schematic diagram of the structure of a battery device 100 according to an embodiment of this application is shown. Figure 2 As shown, 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.

[0065] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] As an example, the housing 20 may include a first housing 21 and a second housing 22. The first housing 21 and the second housing 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first housing 21 may be a top cover or a bottom plate.

[0071] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to house the battery cell assembly 10.

[0072] 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.

[0073] 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.

[0074] 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 this application embodiment is not limited to this. As an example, the battery cell 11 can be a cylindrical battery cell, a prismatic battery cell, or a battery cell 11 of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells, etc., and this application has no particular limitation.

[0075] Figure 3 An exploded structural diagram of a battery cell according to some embodiments of this application is shown. For example... Figure 3 As shown, the battery cell 11 provided in the embodiments of this application includes a casing, an electrode assembly 120, and an electrolyte. The electrode assembly 120 is a component in the battery cell 11 where an electrochemical reaction occurs. The electrode assembly 120 and the electrolyte are housed within the casing. As an example, the electrolyte may be liquid, gel-like, or solid.

[0076] Electrode assembly 120 is the component in the battery cell 11 where electrochemical reactions occur. The housing 110 may contain one or more electrode assemblies 120. Electrode assembly 120 includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell 11, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator, located between the positive and negative electrode, prevents short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0077] The electrode assembly 120 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked. In some embodiments, the electrode assembly 120 is a wound structure. The positive and negative electrode sheets are wound into a wound structure. In some embodiments, the electrode assembly 120 is a stacked structure. As an example, multiple positive and negative electrode sheets can be provided, with multiple positive and multiple negative electrode sheets alternately stacked. As an example, multiple positive electrode sheets can be provided, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments. As an example, both positive and negative electrode sheets are folded to form multiple stacked folded segments. As an example, multiple spacers can be provided, respectively disposed between any adjacent positive or negative electrode sheets. As an example, spacers can be continuously provided, disposed between any adjacent positive or negative electrode sheets by folding or winding. In some embodiments, the electrode assembly 120 can be cylindrical, flat, or polygonal, etc. In some embodiments, the electrode assembly 120 is provided with tabs that can conduct current from the electrode assembly 120. The tabs include a positive tab and a negative tab.

[0078] As an example, such as Figure 3 As shown, the outer casing includes a housing 110 and an end cap 130. The end cap 130 covers the opening of the housing 110, and the housing 110 and the end cap 130 together enclose an installation space for mounting components such as the electrode assembly 120.

[0079] Figure 4 This is a cross-sectional schematic diagram of the sidewall of the casing 110 of the battery cell 11 according to some embodiments of this application. Please refer to... Figure 3 and Figure 4 As shown, the housing 110 has a receiving cavity with one end open, which is used to house the electrode assembly 120. A portion of the sidewall of the housing 110 is a laminated structure component, and the remaining portion is a fully dense metal component. The laminated structure component and the fully dense metal component are distributed sequentially along the axial direction of the electrode assembly 120. The laminated structure component is configured such that an inner layer 111, a foam metal layer 112, and an outer layer 113 are sequentially connected from the inside to the outside of the receiving cavity. Both the inner layer 111 and the outer layer 113 are fully dense metal layers.

[0080] The housing 110 is an assembly used to cooperate with the end cap 130 to form the internal environment of the battery cell 11, wherein the formed internal environment can accommodate the electrode assembly 120, electrolyte, and other components. The housing 110 and the end cap 130 can be independent components, with an opening on the housing 110 and the end cap 130 closing the opening to form the internal environment of the battery cell 11. Alternatively, the end cap 130 and the housing 110 can be integrated. Specifically, the end cap 130 and the housing 110 can form a common connecting surface before other components are inserted into the housing, and the end cap 130 closes the housing 110 when it is necessary to encapsulate the interior of the housing 110. The housing 110 can have various shapes and sizes, such as cuboid, cylindrical, or hexagonal prism. Specifically, the shape of the housing 110 can be determined according to the specific shape and size of the electrode assembly 120.

[0081] In this application, the housing 110 has multiple parts sequentially distributed along the axial direction of the electrode assembly 120, at least one part being a fully dense metal component, and at least one part being a laminated structure component. In the laminated structure component, the inner layer 111 is closest to the electrode assembly 120, and the outer layer 113 is furthest from the electrode assembly 120. That is, the side of the inner layer 111 facing away from the outer layer 113 is the inner surface of the housing 110, and the side of the outer layer 113 facing away from the inner layer 111 is the outer surface of the housing 110. The interlayer between the inner layer 111 and the outer layer 113 is made of foamed metal material. Foamed metal material is a type of metal material with a porous structure, also known as porous metal material, containing a large number of pores. Due to the presence of pores, the density of foamed metal material is much lower than that of fully dense metal material; therefore, foamed metal material has lightweight properties and excellent energy absorption (such as thermal energy and impact energy) performance.

[0082] For example, the foam metal layer 112 can be any one of foam metal materials such as foam aluminum, foam magnesium, or foam titanium. Taking foam aluminum as an example, foam aluminum integrates the properties of aluminum and foam metal, achieving a certain balance between rigidity and strength, that is, it has a certain strength and rigidity while achieving lightweight.

[0083] The fully dense metal components and fully dense metal layers can be made from any one of the following fully dense metal materials: pure aluminum and aluminum alloys, copper and copper alloys, titanium and titanium alloys, stainless steel, etc. Fully dense metal materials refer to metal materials that have no internal pores or a density of not less than 98%. For example, the areal density of aluminum foam is 130 g / m³. 3 The areal density of pure aluminum is 2.7 g / m³. 3 It can be seen that the weight of aluminum foam is less than that of pure aluminum for the same volume.

[0084] In this embodiment, the battery cell 11 is designed with a shell 110 in which a connected inner layer 111, a foamed metal layer 112, and an outer layer 113 are sequentially arranged on a portion of the shell sidewall from the inside to the outside of the receiving cavity. The inner layer 111 and the outer layer 113 are fully dense metal layers. The foamed metal layer 112 can maintain a certain structural rigidity and, due to its porous nature, can effectively absorb impact energy and reduce weight. Therefore, compared with the technical solutions of shell 110 made entirely of fully dense metal material and shell 110 made entirely of plastic material, the shell 110 of the battery cell 11 in this embodiment achieves lightweighting without sacrificing too much thickness to achieve the necessary structural strength to meet impact resistance performance. Specifically, under the same structural strength requirements, the weight of the shell 110 in this embodiment is between the weight of the shell 110 made entirely of fully dense metal material and the weight of the shell 110 made entirely of plastic material, and the thickness of the shell 110 in this embodiment is between the thickness of the shell 110 made entirely of fully dense metal material and the thickness of the shell 110 made entirely of plastic material. In summary, the housing 110 of the battery cell 11 in this embodiment achieves a good balance between weight and structural strength, thereby enabling both lightweight housing 110 and increased energy density of battery cell 11.

[0085] In the technical solution where the foam metal layer 112 is located on the innermost side of the stacked structure component and closest to the electrode assembly 120, the presence of pores makes the surface of the foam metal layer 112 uneven. Therefore, during the operation of the battery cell 11, when the electrode assembly 120 expands to contact the foam metal layer 112, the expansion force of the electrode assembly 120 is uneven, which can easily lead to interface problems and affect the safety performance of the battery cell 11. However, in this embodiment, the battery cell 11 benefits from the fact that the foam metal layer 112 is located between the inner layer 111 and the outer layer 113, and the inner layer 111 is a fully dense metal layer. The side of the inner layer 111 facing away from the outer layer 113 has a smooth surface, resulting in a uniform distribution of the expansion force of the electrode assembly 120 when it expands to contact the foam metal layer 112 during the operation of the battery cell 11. This reduces the probability of interface problems and is beneficial to the good safety performance of the battery cell 11. At the same time, this design can also prevent the foam metal layer 112 from being directly impacted. The outer layer 113 protects the foam metal layer 112, enabling the foam metal layer 112 to effectively and reliably absorb impact energy and reduce the risk of the electrode assembly 120 being damaged by impact.

[0086] Furthermore, this application mitigates the conflict between the weight and thickness of the housing 110 by improving the housing 110. As a mechanical structure, changes in the structure and materials of the housing 110 are less likely to cause fluctuations in the performance (such as voltage, capacity, and internal resistance) of the battery cells 11, thus reducing the possibility of the group margin of the battery cell assembly 10 being affected. Here, group margin refers to the consistency of performance among the multiple battery cells 11 that make up the battery cell assembly 10.

[0087] It is understood that "parts of the shell sidewall of the shell 110 are laminated structural components, and the remaining parts are fully dense metal components" means that one or more parts of the shell sidewall are laminated structural components and one or more parts are fully dense metal components. As an example, there is only one laminated structural component and one fully dense metal component, such as... Figure 4 As shown, the fully dense metal component can be the top portion of the housing 110, or the fully dense metal component can be the bottom portion of the housing 110. As an example, there can be two fully dense metal components and one stacked structural component, such as... Figure 5 As shown, along the axial direction of the electrode assembly 120, a stacked structural component is located between two fully dense metal components. As an example, there are two stacked structural components and one fully dense metal component located between the two stacked structural components. In other examples not shown, there are multiple stacked structural components and fully dense metal components, which are alternately distributed along the axial direction of the electrode assembly 120.

[0088] Combination Figure 3 and Figure 4 The following is a detailed description of an embodiment where both the stacked structure component and the fully dense metal component are a single unit.

[0089] According to some embodiments of this application, such as Figure 3 and Figure 4 As shown, the shell sidewall of the housing 110 may include a first portion 110a and a second portion 110b, which are adjacent to and connected along the axial direction of the electrode assembly 120. The first portion 110a forms an opening around the first portion 110a, and an end cap 130 is connected to the first portion 110a to close the opening. The first portion 110a is a fully dense metal component, and the second portion 110b is a laminated structure component.

[0090] In this example, the first part 110a is a fully dense metal component and is located at the top of the housing 110. That is, one part of the housing 110 is entirely made of dense metal, while another part has a multi-layered structure with the interlayer made of foamed metal material. Figure 3 It can be seen that each part of the shell sidewall is a ring structure, and each part is coaxially arranged.

[0091] End cap 130 refers to a component that covers the opening of housing 110 to isolate the internal environment of battery cell 11 from the external environment. The shape of end cap 130 can be adapted to the shape of housing 110 to fit it. Optionally, end cap 130 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 130 is less prone to deformation under pressure and impact, giving battery cell 11 higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on end cap 130. Electrode terminals can be used for electrical connection with electrode assembly 120 to output or input electrical energy to battery cell 11.

[0092] As an example, the end cap 130 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold. The end cap 130 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0093] As some embodiments of this application, the first part 110a can be replaced with a stacked structural component, and the second part 110b can be replaced with a stacked structural component.

[0094] In contrast, in the embodiment where the first part 110a surrounding the opening on the housing 110 is a fully dense metal component and the second part 110b is a laminated structure component, under the condition that the housing 110 can meet the impact resistance requirements, it can not only balance the lightweight of the housing 110 and the improvement of the energy density of the battery cell 11, but also the opening end face of the housing 110 surrounding the opening is smooth and dense. This can prevent the possibility of dust and other impurities and moisture from the external environment entering from the opening end face of the housing 110 and remaining in the foam metal layer 112, thereby reducing the possibility that the electrode assembly 120 in the cavity will be affected by the impurities and moisture remaining in the foam metal layer 112, which would affect its safety performance.

[0095] Understandably, when both the stacked structure component and the fully dense metal component are a single unit, the fabrication methods for the shell sidewalls are similar and diverse. Here, we will focus on... Figure 4 The shell sidewall of the shell 110 shown is described as a representative example.

[0096] Figure 6 This diagram illustrates the assembly of the casing sidewall of the battery cell 11's housing 110 according to some embodiments of this application. Please refer to... Figure 6 First, the inner layer 111 and the outer layer 113 of the second part 110b can be fixedly connected to the first part 110a and together enclosed to form a groove 114. The end of the groove 114 facing away from the first part 110a has an opening. Then, the foam metal layer 112 can be installed.

[0097] As some embodiments of this application, the opening can be used to allow the foam metal block to pass through, and the groove 114 is used to receive the foam metal block and allow the foam metal block to foam to form a foam metal layer 112.

[0098] In other words, in this method, the foam metal layer 112 is formed directly in the groove 114 by a foaming method using a foam metal block. In this example, the preparation process of the shell sidewall is as follows: S11, the inner layer 111, the outer layer 113 and the first part 110a are fixedly connected to form a pre-assembled part, the outer layer 113 is arranged around the inner layer 111 and the two are spaced apart from each other, and the pre-assembled part has a groove 114; S12, the foam metal block is placed into the groove 114 through the opening, and the foam metal block is foamed to form the foam metal layer 112 by a foaming method.

[0099] In this embodiment, the foam metal layer 112 is formed by directly foaming the foam metal block placed in the groove 114. Firstly, due to the limitation of the groove wall of the groove 114, the certainty of the foam metal block foaming into the foam metal layer 112 is higher. Secondly, the surface of the foam metal layer 112 is closely connected with the groove wall of the groove 114, which will have a positive effect on improving the structural strength of the shell sidewall.

[0100] For further embodiments of this application, please refer to [the relevant documentation]. Figure 6 The opening can also be configured to allow the foam metal layer 112 to pass through, and the foam metal layer 112 is inserted into the groove 114.

[0101] In other words, in this method, a foam metal layer 112 is pre-formed outside the groove 114 by a foaming method, and then the foam metal layer 112 is installed into the groove 114. In this example, the preparation process of the shell sidewall is as follows: S21, the inner layer 111, the outer layer 113 and the first part 110a are fixedly connected to form a pre-assembled part, the outer layer 113 is arranged around the inner layer 111 and the two are spaced apart from each other, and the pre-assembled part has a groove 114; S22, the foam metal layer 112 is made; S23, the foam metal layer 112 is inserted into the groove 114 through the opening, so that the foam metal layer 112 and the groove 114 are inserted and matched.

[0102] The preparation order of S21 and S22 is not limited; they can be carried out sequentially or simultaneously.

[0103] In this embodiment, the foam metal layer 112 is pre-formed and then inserted into the groove 114, so that the preparation of the foam metal layer 112 and the preparation of the pre-assembled parts can be carried out simultaneously as two independent processes on the battery production line. This can significantly improve the preparation efficiency of the casing 110 and shorten the production cycle of the casing 110.

[0104] According to some embodiments of this application, based on the embodiment in which the foam metal layer 112 and the groove 114 are inserted and matched, the foam metal layer 112 can be further bonded to the inner layer 111 and the outer layer 113.

[0105] The foam metal layer 112 has a first surface and a second surface facing away from each other along its thickness direction, with the first surface closer to the electrode assembly 120 than the second surface. The groove 114 has a first groove sidewall and a second groove sidewall that are opposite and parallel to each other, with the first groove sidewall closer to the electrode assembly 120 than the second groove sidewall. At least one of the first surface and the first groove sidewall is coated with an adhesive. Similarly, at least one of the second surface and the second groove sidewall is coated with an adhesive. As disclosed herein, the adhesive can be applied using coating processes such as dot coating, brush coating, spray coating, roller coating, and dip coating.

[0106] The adhesive can be one or more of ethyl cyanoacrylate, polyurethane adhesive, epoxy resin adhesive, etc. Specifically, S24 can be performed after S22 and before S23. In S24, the adhesive is applied to the first surface and / or the sidewall of the first groove, and the adhesive is applied to the second surface and / or the sidewall of the second groove. After S23, the adhesive is dried by natural air drying, oven drying, or other techniques.

[0107] In this embodiment, by making the foam metal layer 112, which is inserted into the groove 114, also bonded to the inner layer 111 and the outer layer 113, the connection reliability of the foam metal layer 112 with the inner layer 111 and the outer layer 113 can be further improved. This is conducive to further improving the connection reliability and structural strength of the second part 110b, thereby further positively impacting the impact resistance of the shell 110.

[0108] Steps S11 and S21 described above can be implemented using any one of welding, snap-fit, screw-fit, adhesive, or integral molding techniques. According to some embodiments of this application, such as... Figure 6 As shown, the inner layer 111 of the second part 110b, the outer layer 113 of the second part 110b, and the first part 110a can be integrally formed.

[0109] In this example, the inner layer 111 and the outer layer 113 of the second part 110b can be made of the same fully dense metal material as the first part 110a. The pre-assembled parts can be manufactured using integral forming processes such as casting, extrusion molding, stamping, and stretching.

[0110] In this embodiment, the inner layer 111 and the outer layer 113 of the second part 110b are connected to the first part 110a to form a single unit. Compared with the connection method by assembly, on the one hand, the assembly process of the inner layer 111 and the outer layer 113 of the second part 110b with the first part 110a is eliminated, which is beneficial to improving the manufacturing efficiency of the shell sidewall. On the other hand, without increasing the cost, the structural strength of the shell sidewall can be effectively improved, which can further have a positive effect on the impact resistance of the shell 110.

[0111] According to some embodiments of this application, the first part 110a and the second part 110b can be connected by assembly.

[0112] In other words, the foam metal layer 112 is first compositely connected with the inner layer 111 and the outer layer 113 to form the second part 110b, making the second part 110b a whole. Then, the first part 110a and the compositely connected second part 110b are assembled and connected. In this example, the preparation process of the shell sidewall is as follows: S31, providing the first part 110a; S32, providing the second part 110b; S33, stacking one of the first part 110a and the second part 110b on the other, and assembling and connecting the first part 110a and the second part 110b using any one or more of welding, snap-fit, screwing, and bonding techniques.

[0113] The preparation order of S31 and S32 is not limited; they can be carried out sequentially or simultaneously.

[0114] In this embodiment, the first part 110a and the second part 110b are formed separately and then assembled. This allows the forming of the first part 110a and the second part 110b to be carried out simultaneously as two independent processes on the battery production line. That is, the first part 110a and the second part 110b can be produced independently and synchronously, which facilitates modular manufacturing.

[0115] In the second part 110b, the foam metal layer 112 can be connected to the inner layer 111 and the outer layer 113 using one or more of welding, snap-fit, screwing, and adhesive techniques. According to some embodiments of this application, when the first part 110a and the second part 110b are assembled together, the foam metal layer 112 can further be bonded to the inner layer 111 and the outer layer 113.

[0116] In this example, the specific implementation steps of step S32 above can be as follows: S321, providing a foam metal layer 112, and one of an inner layer 111 and an outer layer 113, and adhering the foam metal layer 112 to one of the inner layer 111 and the outer layer 113 using an adhesive; S322, providing the other of the inner layer 111 and the outer layer 113, and adhering the foam metal layer 112 to the other of the inner layer 111 and the outer layer 113 using an adhesive.

[0117] The bonding process is used to connect the foam metal layer 112 with the inner layer 111 and the outer layer 113. Compared with the welding process, it reduces the risk of pore collapse caused by the high temperature generated during the welding process. In addition, the adhesive can penetrate into the pores on the surface of the foam metal layer 112, which is conducive to achieving a stable connection between the foam metal layer 112 and the inner layer 111 and the outer layer 113.

[0118] According to some embodiments of this application, the foam metal layer 112 is formed by foam metal blocks directly in the groove 114 by foaming, and the thickness of the shell sidewall of the shell 110 is equal everywhere, and the thickness T of the shell sidewall can satisfy: T≥10mm.

[0119] According to some embodiments of this application, the foam metal layer 112 is inserted into the groove 114, or the first part 110a and the second part 110b are connected by an assembly method; and the foam metal layer 112 is bonded to the inner layer 111 and the outer layer 113, the thickness of the shell sidewall of the shell 110 is equal everywhere, and the thickness T of the shell sidewall can satisfy: 0mm < T < 10mm.

[0120] In other words, when the thickness of the shell sidewall is greater than or equal to 10 mm, the foam metal layer 112 is directly foamed into the groove 114 using a foaming process. In this way, the foam metal layer 112 naturally forms a continuous contact layer with the inner layer 111 and the outer layer 113 through foaming, resulting in a tight connection between the foam metal layer 112 and the inner and outer layers 113. This effectively enhances the bonding strength between the foam metal layer 112 and the inner and outer layers 111, thereby improving the structural strength of the shell sidewall. When the thickness of the shell sidewall is less than 10 mm, the volume of the groove 114 is small. Using a pre-fabricated foam metal layer 112 and bonding it together avoids defects such as uneven pores and insufficient strength caused by limited foaming space during the foaming process, and helps to ensure a uniform thickness of the foam metal layer 112.

[0121] It is understandable that the greater the thickness of the shell sidewall, the higher the structural strength requirement. This embodiment employs this design: for relatively thick shell sidewalls, the foam metal layer 112 is directly foamed within the groove 114, which helps improve the structural strength of the shell sidewall, enabling it to meet impact resistance requirements. For relatively thin shell sidewalls, bonding the pre-formed foam metal layer 112 reduces the possibility of uneven thickness and poor bonding of the foam metal layer 112 due to limited foaming space during the foaming process.

[0122] According to some embodiments of this application, the thickness of the shell sidewall of the shell 110 is equal everywhere and is T, and the ratio of the thickness t of the foam metal layer 112 to the thickness T of the shell sidewall of the shell 110 can satisfy: 0.33≤t / T≤0.5.

[0123] The t / T can be any value among 0.33mm, 0.375mm, 0.428mm, and 0.5mm.

[0124] In this embodiment, the thickness t of the foam metal layer 112 does not exceed half of the shell sidewall thickness T. Extensive experiments have proven that this can minimize the weight of the shell sidewall while maintaining a certain structural strength to meet impact resistance requirements.

[0125] Furthermore, provided that the value of t / T falls within the range of [0.33, 0.5], the thickness t of the foam metal layer 112 can satisfy: 3mm ≤ t ≤ 8mm. Specifically, the thickness t of the foam metal layer 112 can be any value selected from 3mm, 4mm, 5mm, 6mm, 7mm, and 8mm. In this embodiment, the thicknesses of the inner layer 111 and the outer layer 113 can be equal or different, and the value range of the thicknesses of the inner layer 111 and the outer layer 113 can satisfy [1mm, 4mm], specifically any value selected from 1mm, 2mm, 3mm, and 4mm. As an example, if the thickness t of the foam metal layer 112 is 3mm, and the thicknesses of both the inner layer 111 and the outer layer 113 are 2mm, then the thickness T of the shell sidewall is 7mm.

[0126] Figure 7 This is a partial cross-sectional schematic diagram of the battery cell 11 with the housing 110 and end cap 130 mating in some embodiments of this application. Please refer to some embodiments of this application. Figure 3 , Figure 4 and Figure 7Based on an embodiment where the shell sidewall includes a first part 110a and a second part 110b, and the first part 110a is a fully dense metal component located at the top of the shell 110, the end cap 130 can be welded to the first part 110a to form a welded portion 140. The welded portion 140 forms a weld depth on the first part 110a that is less than the height of the first part 110a in the axial direction of the electrode assembly 120.

[0127] To enable the end cap 130 to be welded to the first portion 110a, in this example, the end cap 130 is specifically made of metal materials such as copper, iron, aluminum, stainless steel, or aluminum alloy. The welding process for connecting the end cap 130 to the first portion 110a can be either spot welding or continuous welding, and the welding direction can be parallel to or perpendicular to the axial direction of the electrode assembly 120. The weld depth formed by the welded portion 140 on the first portion 110a is less than the height of the first portion 110a along the axial direction of the electrode assembly 120, indicating that the welded portion 140 does not extend to the second portion 110b along the axial direction of the electrode assembly 120.

[0128] In this embodiment, the end cap 130 is welded to the first part 110a, ensuring a reliable connection between the end cap 130 and the housing 110, thus enabling the end cap 130 to reliably seal the opening. Furthermore, this embodiment ensures that the welded portion 140 does not extend axially into the second part 110b of the electrode assembly 120. This reduces the possibility of thermal damage to the foam metal layer 112 caused by the high temperature generated during welding, which could lead to pore collapse of the foam metal layer 112. This effectively protects the integrity of the pore structure of the foam metal layer 112, thereby effectively protecting the lightweight, energy-absorbing, and heat-insulating properties of the foam metal layer 112.

[0129] Of course, in other embodiments of this application, snap-fit ​​technology, screw-fit technology, adhesive technology and integral molding technology can also be used to connect the end cap 130 and the first part 110a.

[0130] According to some embodiments of this application, the porosity of the foam metal layer 112 can be designed to be greater than 80%.

[0131] The porosity of the foam metal layer 112 can be selected from any value among 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, etc.

[0132] This embodiment achieves a high porosity in the foam metal layer 112, resulting in a significantly lower weight compared to a fully dense metal layer while maintaining the same volume. This effectively reduces the weight of the shell 110. Furthermore, by rationally designing the shape, size, and distribution of the pores, the laminated structure component achieves sufficient structural strength to meet impact resistance requirements. In other words, this helps to achieve the goal of lightweighting and thinning of the shell 110 while meeting impact resistance requirements.

[0133] Referring to the preceding text, as an example, the shell sidewall of shell 110 can also be divided into three parts, such as... Figure 5 As shown, along the axial direction of the electrode assembly 120, the three parts are a first part 110a, a second part 110b, and a third part 110c. The first part 110a is the top portion of the housing 110 and forms an opening around it, while the third part 110c is the bottom portion of the housing 110. The first part 110a and the third part 110c are fully dense metal components, and the second part 110b is a stacked structure component. In this example, one preparation process for the housing sidewall may involve performing S40 after S12 or after S23. In S40, the third part 110c is provided, and the third part 110c is assembled and connected to the second part 110b.

[0134] Referring to the preceding text, as an example, the shell sidewall of the housing 110 can also be divided into four parts along the axial direction of the electrode assembly 120: a fully dense metal component and a stacked structure component. The inner layer 111 and outer layer 113 of each stacked structure component can be integrally formed with an adjacent fully dense metal component. During preparation, two pre-assembled parts can be formed. The two foam metal layers 112 are respectively installed into the grooves 114 of the two pre-assembled parts. The two pre-assembled parts are then stacked and connected by an assembly method.

[0135] 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.

[0136] In one specific embodiment of this application, such as Figure 3 , Figure 4 , Figure 6 and Figure 7As shown, the outer casing of the battery cell 11 includes a housing 110 and an end cap 130. The housing 110 has a receiving cavity with an opening at one end for accommodating the electrode assembly 120, and the end cap 130 is used to close the opening. The sidewall of the housing 110 is divided into a first part 110a and a second part 110b along the axial direction of the electrode assembly 120. Both the first part 110a and the second part 110b are annular structures. The first part 110a is stacked on top of the second part 110b and is used to form the opening. The second part 110b has an inner layer 111, a foamed aluminum layer, and an outer layer 113 sequentially arranged from the inside to the outside of the receiving cavity. The inner layer 111, the outer layer 113, and the first part 110a are formed into an aluminum part using an integral molding process. The first part 110a is connected to the end cap 130 by welding, and the welded portion 140 formed on the first part 110a has a weld depth less than the height of the first part 110a in the axial direction of the electrode assembly 120, that is, along the axial direction of the electrode assembly 120, the welded portion 140 does not extend to the second part 110b. The porosity of the aluminum foam layer is greater than 80%.

[0137] When the thickness T of the shell sidewall is greater than or equal to 10 mm, the preparation process of the shell sidewall is as follows: the inner layer 111, the outer layer 113 and the first part 110a are made by integral molding process, that is, the inner layer 111, the outer layer 113 and the first part 110a are integrally molded. At this time, the three together enclose to form a groove 114, and one end of the groove 114 has an opening; then the foam aluminum block is placed into the groove 114 from the opening, so that the foam aluminum block foams in the groove 114 to form a foam aluminum layer.

[0138] When the thickness T of the shell sidewall is less than 10 mm, the preparation process of the shell sidewall is as follows: the inner layer 111, the outer layer 113 and the first part 110a are made by integral molding process, that is, the inner layer 111, the outer layer 113 and the first part 110a are integrally molded, and the three together form a groove 114, one end of the groove 114 has an opening; then the first side and / or the first groove sidewall of the pre-formed foam aluminum layer are coated with adhesive, and the second side and / or the second groove sidewall of the pre-formed foam aluminum layer are coated with adhesive; then the foam aluminum layer is inserted into the groove 114 from the opening, so that the foam aluminum layer and the groove 114 are inserted and fitted; then the drying technology is used for drying.

[0139] Furthermore, the thickness of the aluminum foam layer is 3mm, the thickness of the inner layer 111 and the outer layer 113 is 2mm, and the thickness of all parts of the shell sidewall is equal, i.e., 7mm. Experimental verification shows that compared with the 7mm thick aluminum shell 110, the overall weight of the shell 110 in this embodiment can be reduced by more than 30%.

[0140] 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 cell, characterized in that, include: Electrode assembly; The housing has a receiving cavity with one open end for accommodating the electrode assembly; a portion of the housing sidewall is a stacked structure component and the remaining portion is a fully dense metal component, the stacked structure component and the fully dense metal component are sequentially distributed along the axial direction of the electrode assembly, the stacked structure component is configured to have a connected inner layer, a foamed metal layer and an outer layer from the inside to the outside of the receiving cavity, the inner layer and the outer layer are both fully dense metal layers.

2. The battery cell according to claim 1, characterized in that, The shell sidewall of the housing includes a first part and a second part, the first part and the second part being adjacent to and connected along the axial direction of the electrode assembly, the first part forming the opening, the first part being the fully dense metal component, and the second part being the laminated structure component; The battery cell also includes an end cap, which is connected to the first part and is used to close the opening.

3. The battery cell according to claim 2, characterized in that, The inner layer of the second part and the outer layer of the second part are fixedly connected to the first part and together enclose to form a groove, and the end of the groove facing away from the first part has an opening; The opening is for the passage of the foam metal block, and the groove is for receiving the foam metal block and allowing the foam metal block to foam to form the foam metal layer.

4. The battery cell according to claim 3, characterized in that, The thickness of the shell sidewall is equal everywhere and is T, wherein T satisfies: T≥10mm.

5. The battery cell according to claim 2, characterized in that, The inner layer of the second part and the outer layer of the second part are fixedly connected to the first part and together enclose to form a groove, and the end of the groove facing away from the first part has an opening; The opening allows the foam metal layer to pass through, and the foam metal layer is inserted into the groove.

6. The battery cell according to claim 2, characterized in that, The first part and the second part are assembled and connected.

7. The battery cell according to claim 5 or 6, characterized in that, The foam metal layer is bonded to the inner layer and the outer layer.

8. The battery cell according to claim 7, characterized in that, The thickness of the shell sidewall is equal everywhere and is T, where T satisfies: 0mm < T < 10mm.

9. The battery cell according to any one of claims 2 to 5, characterized in that, The inner layer of the second part and the outer layer of the second part are integrally formed with the first part.

10. The battery cell according to any one of claims 2 to 9, characterized in that, The end cap is welded to the first part to form a welded section, and the welded section on the first part has a weld depth that is less than the height of the first part in the axial direction of the electrode assembly.

11. The battery cell according to any one of claims 1 to 10, characterized in that, The thickness of the shell sidewall is the same everywhere and is T. The ratio of the thickness t of the foam metal layer to the thickness T of the shell sidewall satisfies: 0.33≤t / T≤0.

5.

12. The battery cell according to any one of claims 1 to 11, characterized in that, The porosity of the foamed metal layer is greater than 80%.

13. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1 to 12.

14. An electrical appliance, characterized in that, The electrical device includes a battery cell as described in any one of claims 1 to 12, or the electrical device includes a battery device as described in claim 13.

15. An energy storage device, characterized in that, The energy storage device includes a single battery cell as described in any one of claims 1 to 12, or the energy storage device includes a battery device as described in claim 13.

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