Battery cell, battery device, and electric device
Patent Information
- Application Number
- CN202521841943.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-28
- Publication Date
- 2026-09-08
- Estimated Expiration
- 2035-08-28
AI Technical Summary
[0015] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.
Smart Images
Figure CN224732776U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical appliance. Background Technology
[0002] With the development of new energy technologies, batteries are being used more and more widely, such as in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, and power tools.
[0003] Welding is required during battery assembly, and how to reduce the risk of accidental damage to other components caused by the welding process is also one of the research problems in this field. Utility Model Content
[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can reduce the risk of burns to the electrode terminals during the battery cell welding process and improve the electrical connection stability of the battery cell.
[0005] In a first aspect, this application provides a battery cell, including a casing, an electrode assembly, an electrical connector, and electrode terminals. The casing includes a housing and an end cap, the housing having a receiving cavity and an opening, and the end cap closing onto the opening. The electrode assembly is disposed within the receiving cavity, and the electrical connector is disposed on the surface of the end cap opposite to the receiving cavity. The electrode terminal penetrates the end cap, one end of the electrode terminal being electrically connected to the electrode assembly, and the other end being connected to the electrical connector. A protective coating is provided on the outer peripheral wall of the electrode terminal, the protective coating including a heat-absorbing layer covering the outer peripheral wall and a heat-reflective layer disposed on the surface of the heat-absorbing layer opposite to the electrode terminal.
[0006] In the technical solution of this application embodiment, a shell is provided to house the electrode assembly. The housing cavity is a sealed space, providing a stable operating environment for the electrode assembly and reducing the impact of external impurities and moisture on the electrode assembly. The electrode terminals are located on the end cap and are electrically connected to the electrode assembly and the electrical connector, facilitating the transmission of electrical energy from the battery cell. In particular, a protective coating is provided on the outer wall of the electrode terminals, which can reduce the laser erosion caused by the laser during laser welding by reflecting part of the laser and absorbing part of the heat generated by the laser, thereby improving the structural stability and electrical connection stability of the electrode terminals and ultimately enhancing the operational stability of the battery cell.
[0007] In some embodiments, the heat-absorbing layer is a porous structure layer with interconnected pores inside. In the above structure, making the heat-absorbing layer a porous structure layer can increase the specific surface area and improve the heat absorption efficiency.
[0008] In some embodiments, the morphology of the pores includes at least one of honeycomb, spherical, or irregular shapes. The above-described structure facilitates manufacturing, and the honeycomb and spherical cavity structures are relatively stable, which can improve the effective heat absorption life of the porous structure layer.
[0009] In some embodiments, the pore wall thickness in the heat-absorbing layer exhibits a gradient, with the pore wall thickness near the electrode terminal being greater than that away from the electrode terminal. In the above structure, the larger pore wall thickness near the electrode terminal and the smaller pore wall thickness near the laser welding side can improve the heat absorption efficiency on the outer side of the heat-absorbing layer, while the larger wall thickness on the inner side ensures the overall structural stability and enhances the connection stability between the heat-absorbing layer and the electrode terminal.
[0010] In some embodiments, the change in pore wall thickness is continuous and gradual, or the change in pore wall thickness is stepped and layered. The above structure can improve the heat absorption efficiency of the heat-absorbing layer and is easy to manufacture and widely apply.
[0011] In some embodiments, the porous structure layer is at least one of an aluminum foam layer, a copper foam layer, an alumina ceramic porous layer, or a silicon carbide ceramic porous layer. The above structure can form a heat-absorbing layer with a porous structure, effectively improving the heat absorption efficiency of the heat-absorbing layer.
[0012] In some embodiments, at least a portion of the pores in the porous structure layer are filled with a phase change material. By filling with a phase change material, the heat from the laser can be stored, reducing heat damage to the electrode terminals, improving the product yield of the battery cell, and enhancing the operational stability of the battery cell.
[0013] In some embodiments, the heat-reflective layer is a smooth, dense ceramic layer, or a composite structure layer formed by alternating layers of metal and ceramic. This structure can reflect laser light, reducing the amount of laser light entering the heat-absorbing layer and minimizing damage to the electrode terminals.
[0014] In some embodiments, the thickness H of the heat-reflective layer is: 5μm ≤ H ≤ 20μm. By setting a reasonable thickness of the heat-reflective layer, the efficiency of laser reflection can be improved while reducing the space occupied by the heat-reflective layer.
[0015] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.
[0016] Thirdly, 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.
[0017] 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
[0018] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.
[0019] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;
[0020] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;
[0021] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;
[0022] Figure 4 This is a schematic diagram of the structure of the adapter piece provided in some embodiments of this application;
[0023] Figure 5 for Figure 4 A magnified structural diagram of part A in the middle;
[0024] Figure 6 This is a schematic diagram of the structure of the protective coating provided in some embodiments of this application.
[0025] Detailed Explanation of Reference Numerals
[0026] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Housing space; 6. Battery cell; 10. Electrode assembly; 101. Electrode body; 102. Tab; 20. Shell; 30. End cap; 40. Housing; 50. Electrode terminal; 60. Electrical connector; 70. Protective coating; 701. Heat-absorbing layer; 702. Heat-reflective layer; 703. Phase change material; 80. Adapter piece. Detailed Implementation
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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).
[0033] 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.
[0034] 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.
[0035] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.
[0036] In this application, "multiple" means two or more (including two).
[0037] In the embodiments of this application, the battery cell can be a secondary battery, which refers to a type of battery that can be used again after the battery cell has been discharged by recharging to activate the active materials.
[0038] The battery cell 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.
[0039] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.
[0040] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.
[0041] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.
[0042] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.
[0043] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the electrode tab. The electrode terminal can be directly connected to the electrode tab, or it can be indirectly connected to the electrode tab through an adapter piece. The electrode terminal can be provided on the end cap or on the housing. Optionally, the electrode terminal and the adapter piece are integrally formed.
[0044] The end caps and housings of battery cells are usually connected by laser welding. When laser welding is used to connect the end caps and housings, the high energy laser beam can cause local high temperature in the welding area, which can damage the electrode terminals and reduce the structural stability and conductivity of the electrode terminals.
[0045] In view of this, the battery cell provided in this application has a protective coating on the outer wall of the electrode terminal, which can reduce the laser's heat during the laser welding process by reflecting part of the laser and absorbing part of the heat generated by the laser, thereby reducing the laser's ablation of the electrode terminal, improving the structural stability and electrical connection stability of the electrode terminal, and thus improving the operational stability of the battery cell.
[0046] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.
[0047] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.
[0048] As an example, the battery module can be housed in the housing by fixing it to the housing.
[0049] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.
[0050] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.
[0051] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.
[0052] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.
[0053] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.
[0054] Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.
[0055] like Figure 1 As shown, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.
[0056] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.
[0057] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.
[0058] Figure 2 This is a schematic diagram of a battery explosion provided for some embodiments of this application. For example... Figure 2 As shown, the battery device 2 includes a housing 5 and battery cells 6, with the battery cells 6 housed within the housing 5. The battery cell 6 can be the smallest unit constituting the battery device 2.
[0059] The housing 5 is used to house the battery cell 6, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 6. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.
[0060] In the battery device 2, multiple battery cells 6 can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel.
[0061] like Figure 2 As shown, the battery cell 6 includes a housing 20, which includes an end cap 30 and a casing 40. The casing 40 has an opening, and the end cap 30 covers the opening. The casing 40 may have one or more openings. The end cap 30 may also be provided one or more times. The electrode assembly 10 is disposed inside the housing 20. The electrode assembly 10 typically includes an electrode body 101 and a tab 102 extending from one side of the electrode body 101.
[0062] In some embodiments, at least one electrode terminal 50 is provided on the housing 20, and the electrode terminal 50 is electrically connected to the tab 102. The electrode terminal 50 can be directly connected to the tab 102, or it can be indirectly connected to the tab 102 through a current collector. The electrode terminal 50 can be provided on the end cap 30 or on the housing 40.
[0063] Please refer to the reference. Figures 3 to 4 , Figure 3 This is an exploded structural diagram of the battery cell 6 provided in some embodiments of this application. Figure 4 This is a schematic diagram of the structure of the adapter piece 80 provided in some embodiments of this application.
[0064] As shown in the figure, the battery cell 6 provided in this embodiment includes a housing 20, an electrode assembly 10, an electrical connector 60, and an electrode terminal 50. The housing 20 includes a shell 40 and an end cap 30. The shell 40 has a receiving cavity and an opening, and the end cap 30 closes to the opening. The electrode assembly 10 is disposed in the receiving cavity, and the electrical connector 60 is disposed on the side surface of the end cap 30 opposite to the receiving cavity. The electrode terminal 50 penetrates the end cap 30, with one end of the electrode terminal 50 electrically connected to the electrode assembly 10 and the other end connected to the electrical connector 60. A protective coating 70 is provided on the outer peripheral wall of the electrode terminal 50. The protective coating 70 includes a heat-absorbing layer 701 covering the outer peripheral wall and a heat-reflective layer 702 disposed on the side surface of the heat-absorbing layer 701 opposite to the electrode terminal 50.
[0065] The electrode terminal 50 can be a columnar structure or a protrusion on the adapter plate 80, which is used to connect the tabs 102 of the electrode assembly 10. An insulating layer is provided between the electrical connection piece 60 and the end cap 30, and the electrical connection piece 60 is electrically connected to the electrode terminal 50.
[0066] The protective coating 70 can be formed on the outer wall of the electrode terminal 50 using methods such as physical vapor deposition, chemical vapor deposition, or electroplating. Optionally, the protective coating 70 is disposed around the outer periphery of the electrode terminal 50. The heat-absorbing layer 701 is used to absorb heat, and can be, for example, made of a metal, a ceramic, or a metal-ceramic composite material. The heat-reflective layer 702 can be made of a material with high reflectivity, such as a metal oxide material, a multilayer composite material, etc.
[0067] In the technical solution of this application embodiment, a housing 20 is provided to accommodate the electrode assembly 10. The accommodating cavity is a sealed space, providing a stable operating environment for the electrode assembly 10 and reducing the impact of external impurities and moisture on the electrode assembly 10. The electrode terminals 50 are disposed on the end cap 30 and are electrically connected to the electrode assembly 10 and the electrical connecting piece 60, respectively, which facilitates the transmission of electrical energy from the battery cell 6. In particular, a protective coating 70 is provided on the outer wall of the electrode terminals 50, which can reduce the laser's ablation during laser welding by reflecting part of the laser and absorbing part of the heat generated by the laser, thereby improving the structural stability and electrical connection stability of the electrode terminals 50 and thus improving the operational stability of the battery cell 6.
[0068] like Figure 5 As shown, in some embodiments of this application, the heat-absorbing layer 701 is a porous structure layer with interconnected pores inside.
[0069] The porous structure significantly increases the contact area between the heat-absorbing layer 701 and its surrounding environment, thus increasing its specific surface area. During laser welding, a large amount of heat is generated when the laser irradiates the surface of the electrode terminal 50. The porous heat-absorbing layer 701 provides more heat absorption sites, allowing heat to be absorbed more rapidly. Compared to a solid heat-absorbing layer 701, the surface area of the porous structure is multiplied for the same volume, enabling more efficient interaction with the heat energy generated by the laser, thereby significantly improving heat absorption efficiency.
[0070] In the above structure, the heat absorption layer 701 is set as a porous structure layer, which can increase the specific surface area and improve the heat absorption efficiency through the porous structure.
[0071] In some embodiments of this application, the morphology of the pores includes at least one of honeycomb, spherical, or irregular shapes.
[0072] Spherical porous structures are typically achieved through template methods or 3D printing. Regular spherical pores can be formed by mixing a uniform spherical pore-forming agent (such as polymer microspheres) with metal powder and then sintering the mixture. This structure exhibits uniform porosity and consistent performance. The sphere is one of the most stable shapes in nature, minimizing stress concentration. The uniform stress distribution around the spherical pores reduces the likelihood of crack initiation, resulting in a long structural lifespan. Furthermore, it provides uniform and isotropic thermal properties, with equal heat diffusion in all directions.
[0073] Biomimetic honeycomb-like porous structures can be manufactured using extrusion molding to create porous ceramic honeycombs, or processed into metals through etching or engraving. This structure exhibits excellent thermal conductivity and strength properties in specific directions. Its regular hexagonal structure provides stable mechanical properties, allowing it to withstand maximum loads with minimal material. This structure demonstrates excellent fatigue resistance during repeated thermal expansion and contraction cycles, is less prone to plastic deformation or fracture, and therefore has the longest lifespan. It typically provides highly efficient directional heat conduction channels along the axial direction of the holes.
[0074] Irregularly shaped porous structures are the most common type of porous structure and can be mass-produced into foamed metals (such as aluminum foam and copper foam) through melt foaming or powder sintering. This process is mature, has low manufacturing costs, and is very suitable for large-scale commercial applications.
[0075] The above-mentioned structure is easy to manufacture and mold, and the honeycomb and spherical cavity structures are relatively stable, which can improve the effective heat absorption life of the porous structure layer.
[0076] In some embodiments of this application, the pore wall thickness in the heat absorption layer 701 varies in a gradient, with the pore wall thickness near the electrode terminal 50 being greater than that away from the electrode terminal 50.
[0077] The thinner wall near the reflective layer means that the heat capacity in this area is relatively small, resulting in a faster temperature rise rate. It can quickly reach the temperature matching the laser heat, immediately initiating the heat absorption process with a very sensitive response. The thinner wall and larger porosity promote air convection or thermal radiation, which helps to rapidly diffuse the absorbed heat outward into the environment, preventing heat from accumulating and transferring inward, essentially creating a "heat dissipation zone" on the outside.
[0078] The thick wall on the inner side near the electrode end provides higher mechanical strength and rigidity, capable of withstanding the assembly stress, thermal expansion stress, and possible external vibrations of the electrode terminal 50. This prevents the porous structure from being crushed or deformed due to insufficient strength, ensuring a durable and stable connection. The thick wall also means more material to store heat, resulting in a large heat capacity. When heat is transferred from the outside, this area acts like a "reservoir," absorbing heat and strongly suppressing the temperature rise of the electrode terminal 50 itself, providing thermal protection for the core component. More material also means a better lateral heat conduction path, allowing heat to be rapidly dispersed from local hotspots to the entire heat-absorbing layer 701, achieving temperature homogenization and preventing localized overheating.
[0079] This thickness gradient naturally creates a thermal resistance gradient (thermal resistance gradually increases from the outside to the inside), which tends to dissipate heat along the low thermal resistance path (outwards) rather than forcibly heating the electrode terminal 50 through the high thermal resistance path (inwards). This structure guides the direction of heat flow, diverting excess heat away from the electrode terminal 50, thus achieving directional heat management.
[0080] In the above structure, the hole wall thickness is large near the electrode terminal 50 and small near the laser welding side, which can improve the heat absorption efficiency of the outer side of the heat absorption layer 701. The large wall thickness on the inner side ensures the overall structural stability and improves the connection stability between the heat absorption layer 701 and the electrode terminal 50.
[0081] In some embodiments of this application, the change in hole wall thickness is continuous and gradual, or the change in hole wall thickness is stepped and layered.
[0082] The continuously varying hole wall thickness, with a smooth, uninterrupted change, allows for a gradual increase in wall thickness without abrupt interface changes. This ensures smooth heat transfer, eliminates internal interface thermal resistance, maximizes thermal conductivity and dissipation efficiency, and effectively achieves gradient thermal management. Furthermore, the absence of abrupt interface changes in the gradually varying wall thickness structure results in uniform internal thermal stress distribution during thermal expansion and contraction, eliminating stress concentration points and providing exceptional resistance to thermal fatigue. This makes it less prone to cracking or failure over long-term use, leading to a longer lifespan.
[0083] The variation in pore wall thickness is a stepped layering, meaning that the heat-absorbing layer 701 has multiple porous layers stacked sequentially along the radial direction of the electrode terminals 50. Each layer contains multiple pore structures, and the pore sizes of these structures vary progressively. Pre-fabricated thin layers with different porosities (e.g., 2-3 layers) can be stacked and then connected by pressing, co-sintering, or diffusion welding. The process is simple, mature, and easily integrated into existing production lines, making it ideal for large-scale commercial manufacturing and widespread application. Heat conduction is excellent within each layer.
[0084] The above structure can improve the heat absorption efficiency of the heat absorption layer 701 and facilitate its manufacturing and application.
[0085] In some embodiments of this application, the porous structure layer is at least one of aluminum foam, copper foam, alumina ceramic porous layer, or silicon carbide ceramic porous layer.
[0086] The interior of foamed aluminum or foamed copper, or porous ceramics, is filled with numerous interconnected pores. This increases the internal surface area of the structure, allowing heat to be rapidly dispersed across the vast surface area when conducted from electrode terminal 50, preventing localized heat accumulation and thus quickly reducing the terminal temperature, resulting in extremely high heat absorption efficiency.
[0087] Aluminum and copper are excellent thermal conductors. Even when made porous, their solid framework can still provide a thermal conductivity rate far exceeding that of other porous materials such as polymers, and can quickly diffuse heat from the heat source (terminal) to the entire heat-absorbing layer 701.
[0088] Alumina and silicon carbide ceramics have higher thermal conductivity than ordinary materials and excellent high-temperature resistance, maintaining structural stability under the high-temperature impact of laser welding.
[0089] The above structure can form a heat-absorbing layer 701 with a stable pore structure, which effectively improves the heat absorption efficiency of the heat-absorbing layer 701.
[0090] like Figure 6 As shown, in some embodiments of this application, at least some of the pores in the porous structure layer are filled with phase change material 703.
[0091] For example, materials such as paraffin wax, styrene, and low-melting-point alloys can be used as phase change materials 703 to fill the porous structure. For example, high-purity paraffin wax with a phase change temperature between 70-90℃ has high heat absorption, is inexpensive, non-toxic and harmless, chemically stable, and does not exhibit supercooling, and can effectively absorb the heat generated by laser ablation.
[0092] By filling with phase change material 703, the heat of the laser can be stored, reducing the damage of heat to the electrode terminal 50, improving the product yield of the battery cell 6, and enhancing the operational stability of the battery cell 6.
[0093] In some embodiments of this application, the heat reflective layer 702 is a smooth, dense ceramic layer, or a composite structure layer formed by alternating layers of metal and ceramic.
[0094] A smooth surface produces specular reflection, rather than diffuse reflection, thus reflecting most of the incident laser energy at a specific angle, preventing energy absorption. "Dense" means without pores, with a complete structure, avoiding the risk of laser energy being absorbed by pores. The melting point of ceramics is much higher than that of metals (e.g., alumina melting point 2054℃), so it will not melt, deform, or decompose under the instantaneous high temperature impact of a laser, maintaining the integrity of its smooth surface and exhibiting low performance degradation. The ceramic layer is extremely hard, not easily scratched during battery production, transportation, and assembly, ensuring the long-lasting smoothness of the reflective surface. Furthermore, the ceramic insulating material isolates the risk of short circuits between the electrode terminal 50 and the end cap 30, eliminating the need for additional insulation design. Moreover, the chemically stable properties of ceramic materials make them less likely to react with the porous metal heat-absorbing layer 701, and their coefficient of thermal expansion can be matched through material selection, avoiding cracking and peeling problems caused by thermal expansion and contraction, ensuring the integrity and long-term reliability of the protective component.
[0095] The composite structure, formed by alternating layers of metal and ceramic, reflects a portion of the laser light at the interface between each metal and ceramic layer. By precisely controlling the thickness of each layer—for example, a thickness of 1 / 4 of the laser wavelength—the reflected beams from all interfaces undergo constructive interference in the outgoing direction (i.e., enhanced superposition of reflected light) and destructive interference in the incident direction (i.e., mutual cancellation of transmitted light). This results in a reflection efficiency far exceeding the theoretical limit of a single material layer. Furthermore, the alternating metal layers (such as molybdenum, titanium, and aluminum) act as toughening layers, effectively passivating cracks and preventing the propagation of cracks in the ceramic layer, significantly improving the thermal shock resistance and mechanical toughness of the entire reflective layer.
[0096] The above structure can reflect the laser, reduce the laser's entry into the heat-absorbing layer 701, and reduce damage to the electrode terminal 50.
[0097] In some embodiments of this application, the thickness H of the heat reflective layer 702 is: 5μm≤H≤20μm.
[0098] Setting the lower limit of thickness to 5 μm ensures sufficient mechanical integrity of the reflective layer (whether ceramic or metallic). Setting the upper limit of thickness to 20 μm effectively controls the level of thermal stress. The thicker the coating, the greater its internal stress and the greater the thermal stress generated at the interface, which can easily lead to coating warping, microcracks, or even peeling off from the substrate. 20 μm is an empirical critical value; below this thickness, stress can be effectively controlled, ensuring the reflective layer maintains structural stability and functional reliability during long-term thermal cycling. By setting a reasonable thickness for the thermal reflective layer 702, the efficiency of laser reflection can be improved while reducing the space occupied by the thermal reflective layer 702.
[0099] In some optional embodiments, the battery cell 6 includes a housing 20, an electrode assembly 10, an electrical connector 60, and an electrode terminal 50. The housing 20 includes a shell 40 and an end cap 30. The shell 40 has a receiving cavity and an opening, and the end cap 30 closes to the opening. The electrode assembly 10 is disposed within the receiving cavity, and the electrical connector 60 is disposed on the side surface of the end cap 30 opposite to the receiving cavity. The electrode terminal 50 penetrates the end cap 30, with one end of the electrode terminal 50 electrically connected to the electrode assembly 10 and the other end connected to the electrical connector 60. A protective coating 70 is provided on the outer peripheral wall of the electrode terminal 50. The protective coating 70 includes a heat-absorbing layer 701 covering the outer peripheral wall and a heat-reflective layer 702 disposed on the side surface of the heat-absorbing layer 701 opposite to the electrode terminal 50. The heat-absorbing layer 701 is a porous structure layer with interconnected pores in a honeycomb morphology. The pore wall thickness in the heat-absorbing layer 701 exhibits a gradient, with the pore wall thickness near the electrode terminal 50 being greater than that away from the electrode terminal 50. A portion of the porous structure layer's pores are filled with a phase change material 703. The heat-reflective layer 702 is a smooth, dense ceramic layer.
[0100] This application provides a battery device 2, which includes the battery cell 6 described in the above embodiments. This application also provides an electrical device, which includes the battery device 2 described in the above embodiments. The battery device 2 is used to provide electrical energy. Both the battery device 2 and the electrical device include the battery cell 6 described above. The battery cell 6 has a housing 20 to accommodate an electrode assembly 10. The housing cavity is a sealed space, providing a stable operating environment for the electrode assembly 10 and reducing the impact of external impurities and moisture on the electrode assembly 10. Electrode terminals 50 are disposed on end caps 30 and are electrically connected to the electrode assembly 10 and the electrical connection piece 60, respectively, facilitating the transmission of electrical energy from the battery cell 6. In particular, a protective coating 70 is provided on the outer wall of the electrode terminals 50, which can reduce the laser's erosion during laser welding by reflecting a portion of the laser and absorbing a portion of the heat generated by the laser, thereby improving the structural stability and electrical connection stability of the electrode terminals 50 and enhancing the operational stability of the battery cell 6.
[0101] 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: The housing includes a shell and an end cap, the shell having a receiving cavity and an opening, and the end cap closing onto the opening; The electrode assembly is disposed within the receiving cavity; An electrical connection piece is provided on the surface of the end cap opposite to the receiving cavity; An electrode terminal extends through the end cap. One end of the electrode terminal is electrically connected to the electrode assembly, and the other end is connected to the electrical connection piece. A protective coating is provided on the outer peripheral wall of the electrode terminal. The protective coating includes a heat-absorbing layer covering the outer peripheral wall and a heat-reflective layer disposed on the surface of the heat-absorbing layer facing away from the electrode terminal.
2. The battery cell according to claim 1, characterized in that, The heat-absorbing layer is a porous structure layer with interconnected pores inside.
3. The battery cell according to claim 2, characterized in that, The morphology of the pores includes at least one of honeycomb, spherical, or irregular shapes.
4. The battery cell according to claim 2, characterized in that, The pore wall thickness in the heat absorption layer varies in a gradient, with the pore wall thickness closer to the electrode terminal being greater than that further away from the electrode terminal.
5. The battery cell according to claim 4, characterized in that, The change in the hole wall thickness is either continuous and gradual, or the change in the hole wall thickness is stepped and layered.
6. The battery cell according to claim 2, characterized in that, The porous structure layer is at least one of aluminum foam, copper foam, alumina ceramic porous layer, or silicon carbide ceramic porous layer.
7. The battery cell according to any one of claims 2-6, characterized in that, At least a portion of the pores in the porous structure layer are filled with a phase change material.
8. The battery cell according to any one of claims 1-6, characterized in that, The heat-reflective layer is a smooth, dense ceramic layer, or a composite structure layer formed by alternating layers of metal and ceramic.
9. The battery cell according to claim 8, characterized in that, The thickness H of the heat-reflective layer is: 5μm≤H≤20μm.
10. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-9.
11. An electrical appliance, characterized in that, The electrical equipment includes the battery device as described in claim 10, the battery device being used to provide electrical energy.