Battery cell, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, a shell body of a shell in the battery monomer forms an accommodating cavity with a first opening, an electrode assembly is arranged in the accommodating cavity, and a cover body and the shell body are welded to form a welding part for blocking the first opening; one side of the cover body in the thickness direction is provided with a concave part which is concave inwards, and the concave part is communicated with the welding part; the sealing structure covers the welding part, and at least part of the sealing structure is located in the concave part. In the structure, the sealing structure at least partially positioned in the concave part covers the welding part, so that the sealing structure can seal the welding part, the electrolyte of the battery monomer is not easy to leak after the welding part fails, external impurities are not easy to enter the battery monomer, the reliability of the battery monomer is improved, and the service life of the battery monomer is prolonged. And the reliability of the battery device is improved.

Description

Technical Field

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

[0002] Battery devices have advantages such as high specific energy and high power density, and are widely used in electronic devices and transportation vehicles, such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships and power tools.

[0003] As the application scope of battery devices continues to expand, the requirements for their reliability are also increasing. How to improve the reliability of battery devices is receiving increasing attention from those skilled in the art. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, wherein the battery cell has good sealing properties, which is beneficial to improving the reliability of the battery device.

[0005] In a first aspect, this application provides a battery cell, which includes an electrode assembly, a housing, and a sealing structure. The housing includes a shell and a cover. The shell forms a cavity with a first opening. The electrode assembly is disposed in the cavity. The cover is welded to the shell to form a welded portion that seals the first opening. The cover has an inwardly recessed portion on one side in the thickness direction, and the recess communicates with the welded portion. The sealing structure covers the welded portion, and at least a portion of the sealing structure is located in the recess.

[0006] In the above structure, since the sealing structure located at least partially in the recess covers the welded part, the sealing structure can seal the welded part, so that the electrolyte of the battery cell is not easy to leak after the welded part fails, and external impurities are not easy to enter the battery cell, thereby improving the reliability of the battery cell and thus improving the reliability of the battery device.

[0007] According to some embodiments of the present application, the battery cell has a sealing structure located in the cavity, and a recess is provided on the side of the cover facing the electrode assembly. By providing the recess on the side of the cover facing the electrode assembly, the material containing the sealing structure in the recess can flow to the inner surface of the welded portion facing the cavity, thereby forming the sealing structure in the cavity.

[0008] According to some embodiments of the present application, the sealing structure of the battery cell is a solid-liquid phase change material structure. By setting the sealing structure as a solid-liquid phase change material structure, during the formation of the sealing structure, when the temperature reaches the melting point, the solid-liquid phase change material located in the recess can flow from the recess to the surface of the welded part, so that it can solidify on the surface of the welded part to form a sealing structure when the temperature is below the melting point.

[0009] According to some embodiments of the present application, the melting point of the solid-liquid phase change material is set to T, 65℃≤T≤160℃. This allows the solid-liquid phase change material to reach its melting point and melt under high temperature and static conditions, thus making it fluid. This allows the solid-liquid phase change material in the recess to flow to the surface of the welded part, so that it can solidify on the surface of the welded part to form a sealing structure when the temperature drops later. This prevents the battery cell from being subjected to excessively high temperatures to form a sealing structure, and also makes the sealing structure less likely to melt due to temperature rise caused by factors such as heat generation of the battery cell.

[0010] According to some embodiments of the present application, the solid-liquid phase change material of the battery cell is a paraffin-like material, which gives the solid-liquid phase change material a suitable melting point, thus meeting the conditions for forming a sealed structure.

[0011] According to some embodiments of this application, the battery cell includes a recessed portion and a receiving portion that are interconnected. The receiving portion is connected to a welding portion through the drain portion. The receiving portion is capable of accommodating a solid-liquid phase change material, and the drain portion accommodates a sealing structure. The connection between the receiving portion and the welding portion allows the solid-liquid phase change material in the receiving portion to flow through the drain portion to the surface of the welding portion to form a sealing structure.

[0012] According to some embodiments of the present application, the bottom surface of the drain portion moves closer to the outer surface of the cover relative to the bottom surface of the receiving portion in the direction of the drain portion approaching the welding portion. When the inner surface of the cover is facing upward, the liquid solid-liquid phase change material will flow towards the welding portion and gather under the action of gravity, so that the solid-liquid phase change material can flow smoothly to the surface of the welding portion, which is convenient for subsequent curing to form a sealed structure covering the welding portion.

[0013] According to some embodiments of the present application, the angle between the bottom surface of the drain portion and the bottom surface of the receiving portion is set to A, 0.5°≤A≤25°. This not only allows the liquid solid-liquid phase change material to flow smoothly to the welding portion and collect, but also makes it less likely that the bottom surface of the drain portion will reduce the thickness of the cover due to the large slope, thereby reducing the weakening of the cover structure strength by the recess.

[0014] According to some embodiments of the present application, the battery cell has multiple drainage portions, which are spaced apart circumferentially along the first opening. By setting multiple drainage portions spaced apart circumferentially along the first opening, the recess is connected to the welding portion through the multiple drainage portions, increasing the area of ​​communication between the welding portion and the recess. This allows the solid-liquid phase change material to cover the welding portion over a larger area to form a sealing structure, which is beneficial to improving the sealing effect of the sealing structure on the welding portion.

[0015] According to some embodiments of the battery cell provided in this application, the recess further includes a permeation portion, which connects two adjacent guide portions and is connected to the welding portion. The permeation portion accommodates a sealing structure. The permeation portion can be a structure provided in the recess to increase the communication area between the welding portion and the recess. By connecting the permeation portion to two adjacent guide portions and connecting it to the welding portion, the permeation portion is positioned between the two adjacent guide portions, increasing the communication area between the recess and the welding portion. This allows the solid-liquid phase change material to cover the welding portion over a larger area to form a sealing structure.

[0016] According to some embodiments of this application, the battery cell has a cover with a pressure relief structure, and a second protrusion protrudes from the bottom surface of the receiving portion, surrounding the outer periphery of the pressure relief structure. By protruding from the bottom surface of the receiving portion and surrounding the outer periphery of the pressure relief structure, the second protrusion prevents the solid-liquid phase change material from easily overflowing the second protrusion and entering the pressure relief structure when it melts in the receiving portion, thus reducing the impact of the solid-liquid phase change material on the operation of the pressure relief structure and the possibility of leakage from the pressure relief structure.

[0017] According to some embodiments of the present application, the battery cell has a cover with a liquid injection hole extending through the thickness direction, and a third protrusion protrudes from the bottom surface of the receiving portion, surrounding the outer periphery of the liquid injection hole. By protruding from the bottom surface of the receiving portion and surrounding the outer periphery of the liquid injection hole, the third protrusion prevents the solid-liquid phase change material from easily overflowing the third protrusion and entering the liquid injection hole when it melts in the receiving portion, thus reducing the possibility of leakage of the solid-liquid phase change material from the liquid injection hole.

[0018] According to some embodiments of this application, the battery cell has a cover with an electrode lead-out hole extending through the thickness direction. A first protrusion protrudes from the bottom surface of the receiving portion, surrounding the outer periphery of the electrode lead-out hole. The battery cell includes electrode terminals electrically connected to an electrode assembly, with some of the electrode terminals passing through the electrode lead-out hole. By protruding from the bottom surface of the receiving portion and surrounding the outer periphery of the electrode lead-out hole, the first protrusion prevents the solid-liquid phase change material from easily overflowing the first protrusion and entering the electrode lead-out hole when it melts in the receiving portion, thus reducing the possibility of leakage of the solid-liquid phase change material from the electrode lead-out hole.

[0019] According to some embodiments of the present application, the battery cell further includes a first insulating member disposed on the side of the cover facing the cavity and covering the recess. The electrode terminal includes a first part and a second part connected along the thickness direction of the cover. At least a portion of the first part is located in the electrode lead-out hole, and the second part protrudes from the outer peripheral surface of the first part. A portion of the first insulating member is sandwiched between the first protrusion and the second part, so that the first insulating member can be fixed on the cover under the action of the electrode terminal.

[0020] According to some embodiments of the present application, the battery cell further includes a third part, which is disposed on the side of the cover away from the cavity. A portion of the first part extends out from the electrode lead hole and is riveted to the third part, so that the first part and the third part are connected, and the electrode terminal is fixed on the cover.

[0021] According to some embodiments of this application, the bottom surface of the receiving portion of the battery cell is provided with a fourth protrusion, and a first connecting hole is formed on the side of the fourth protrusion facing the first insulating member. The first insulating member is provided with a first connecting structure, which is inserted into the first connecting hole, thereby improving the connection force between the first insulating member and the cover, so that the first insulating member can be more firmly connected to the cover.

[0022] According to some embodiments of the present application, the battery cell has a fifth protrusion on the side of the cover facing the electrode assembly, protruding relative to the bottom surface of the recess, and the fifth protrusion is connected to the welding portion. The fifth protrusion increases the thickness of the cover at this location, thereby increasing the structural strength of the cover at this location, and enabling the edge portion of the cover to have sufficient strength to be welded to the housing.

[0023] According to some embodiments of this application, a battery cell has a second connection hole formed on the side of the fifth protrusion facing the first insulating member. The first insulating member is provided with a second connection structure, which is inserted into the second connection hole. This can improve the connection force between the first insulating member and the cover, so that the first insulating member can be more firmly connected to the cover.

[0024] According to some embodiments of the present application, the size of the drain portion along the circumferential direction of the first opening is set to L, 0.5mm≤L≤55mm. This not only allows the drain portion to have a sufficiently large communication area with the welding portion, so that the liquid solid-liquid phase change material can flow smoothly to the welding portion, but also prevents the drain portion from weakening the structural strength at the edge of the cover due to the excessive size of the drain portion in the circumferential direction of the first opening.

[0025] Secondly, this application provides a battery device that includes the battery cell provided by any of the above-described technical solutions. Because the battery device includes the battery cell provided by the above-described technical solutions, the battery device has good reliability.

[0026] According to some embodiments of this application, the battery device further includes a housing, in which individual battery cells are housed, and the orientation of the first opening of the individual battery cells has a vertically downward component.

[0027] Thirdly, this application provides an electrical device that includes a battery device provided by any of the above-described technical solutions, wherein the battery is used to provide electrical energy.

[0028] The technical solutions provided by the embodiments of this disclosure bring at least the following beneficial effects:

[0029] This application provides a battery cell including an electrode assembly, a housing, and a sealing structure. The housing shell forms a cavity with a first opening, and the electrode assembly is disposed in the cavity. A cover is welded to the housing to form a weld portion that seals the first opening. The cover has an inwardly recessed portion on one side in the thickness direction, and the recess communicates with the weld portion. The sealing structure covers the weld portion, with at least a portion of the sealing structure located in the recess. In the above structure, since the sealing structure, at least a portion of which is located in the recess, covers the weld portion, the sealing structure can seal the weld portion. This prevents electrolyte leakage from the battery cell even if the weld portion fails, and also prevents external impurities from entering the battery cell, thus improving the reliability of the battery cell and consequently improving the reliability of the battery device.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0032] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application;

[0033] Figure 2 This is a exploded view of a battery device provided in some embodiments of this application;

[0034] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0035] Figure 4 This is a split view of a battery cell provided in some embodiments of this application;

[0036] Figure 5 This is a schematic diagram of the structure of the welded portion of a battery cell provided in some embodiments of this application;

[0037] Figure 6 This is a schematic diagram of the structure of the cover of the battery cell provided in the first embodiment of this application;

[0038] Figure 7This is a schematic diagram of the structure of the cover of the battery cell provided in the second embodiment of this application;

[0039] Figure 8 for Figure 7 Sectional view at point GG;

[0040] Figure 9 for Figure 6 Enlarged view at point F;

[0041] Figure 10 This is a schematic diagram of the structure of the cover of the battery cell provided in the third embodiment of this application;

[0042] Figure 11 A schematic diagram of the structure of a cover with a first insulating element provided in some embodiments of this application from one view.

[0043] Figure 12 A schematic diagram of the structure of a cover with a first insulating element provided in some embodiments of this application from another perspective;

[0044] Figure 13 for Figure 12 Sectional view at EE;

[0045] Figure 14 for Figure 13 Enlarged view of point D in the middle;

[0046] Figure 15 This is a schematic diagram of the structure of a cover with an unmelted solid-liquid phase change material structure provided in some embodiments of this application.

[0047] In the attached diagram:

[0048] 1. Vehicle; 2. Battery unit; 3. Controller; 4. Motor; 5. Housing; 5a. First housing section; 5b. Second housing section; 5c. Receiving space; 7. Battery cell; 8. Electrode assembly; 9. Outer shell; 91. Housing; 92. Cover; 921. Recess; 9211. Drainage section; 9212. Receiving section; 9213. Leakage section; 922. Pressure relief structure; 923. Second protrusion; 924. Injection hole; 925. Third protrusion ; 926, Electrode lead-out hole; 927, First protrusion; 928, Fourth protrusion; 9281, First connecting hole; 929, Fifth protrusion; 9291, Second connecting hole; 10, Cavity; 11, First opening; 12, Welding part; 13, Sealing structure; 14, Solid-liquid phase change material structure; 15, Electrode terminal; 151, First part; 152, Second part; 153, Third part; 16, First insulating element; 17, Second opening. Detailed Implementation

[0049] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0050] It should be noted that, unless otherwise stated, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by those skilled in the art to which the embodiments of this application pertain.

[0051] 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", "circumferential", etc., 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 do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] Furthermore, technical terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of the embodiments of this application, "a plurality of" means two or more (including two), unless otherwise explicitly specified.

[0053] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the 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.

[0054] In the description of the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields.

[0056] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cell assemblies to provide higher voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0057] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0058] A battery cell can be a rechargeable battery cell, which refers to a battery cell that can be recharged after being discharged to activate the active materials and continue to be used.

[0059] Battery cells can be lithium-ion cells, sodium-ion cells, sodium-lithium-ion cells, lithium metal cells, sodium metal cells, lithium-sulfur cells, magnesium-ion cells, nickel-metal hydride cells, nickel-cadmium cells, lead-acid cells, etc.

[0060] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. 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.

[0061] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements.

[0062] In some embodiments, the electrolyte includes an electrolyte salt and a solvent.

[0063] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0064] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0065] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0066] In some embodiments, a single battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0067] As an example, the battery cell can be a prismatic battery cell, including a prismatic battery cell, a blade-shaped battery cell, or a multi-prism battery, such as a hexagonal prism battery. In the embodiments of this application, the battery cell is a blade-shaped battery cell.

[0068] 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.

[0069] 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.

[0070] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0071] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0072] 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.

[0073] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0074] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0075] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0076] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0077] 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.

[0078] In some embodiments, the battery device can be used in an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0079] The sealing performance of individual battery cells has a significant impact on their operation. Poor sealing can easily lead to electrolyte leakage and the entry of external impurities, affecting the normal functioning of the battery cell. In some battery devices, especially those with downward-facing welded openings in the cells, the electrolyte will accumulate at the downward-facing opening due to gravity. If the weld at the opening fails, the electrolyte can easily leak out. The leaked electrolyte may come into contact with the wiring harness, causing short circuits and other hazards, posing a significant threat to the reliability of the battery cell.

[0080] To improve the sealing performance of a battery cell, some embodiments of this application provide a battery cell including an electrode assembly, a housing, and a sealing structure. The housing shell forms a cavity with a first opening, the electrode assembly is disposed in the cavity, and a cover is welded to the housing to form a weld portion that seals the first opening. The cover has an inwardly recessed portion on one side in the thickness direction, which communicates with the weld portion. The sealing structure covers the weld portion, with at least a portion of the sealing structure located in the recess. In the above structure, since the sealing structure, at least a portion of which is located in the recess, covers the weld portion, the sealing structure can seal the weld portion. This prevents electrolyte leakage from the battery cell even if the weld portion fails, and also prevents external impurities from entering the battery cell, thus improving the reliability of the battery cell and consequently improving the reliability of the battery device.

[0081] The battery cells described in the embodiments of this application are applicable to battery devices and electrical devices that use battery devices.

[0082] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, among others. 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.

[0083] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0084] Figure 1 The diagram shows the structural features of a vehicle provided in some embodiments of this application.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] Figure 2 This is a exploded view of a battery device provided in some embodiments of this application. For example... Figure 2 As shown, the battery device 2 includes a housing 5 and battery cells 7, with the battery cells 7 housed within the housing 5. The battery cell 7 can be the smallest unit that makes up a battery.

[0089] The housing 5 is used to house the battery cell 7, 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 7. 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.

[0090] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0091] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0092] In the battery device 2, there can be one or more battery cells 7. If there are multiple battery cells 7, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 7 are connected in both series and parallel. Multiple battery cells 7 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 7 is housed in the housing 5. Alternatively, multiple battery cells 7 can first be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed in the housing 5.

[0093] Some embodiments of this application provide a battery cell 7, see reference Figures 3 to 5 The battery cell 7 includes an electrode assembly 8, a housing 9, and a sealing structure 13. The housing 9 includes a shell 91 and a cover 92. The shell 91 forms a cavity 10 with a first opening 11. The electrode assembly 8 is disposed in the cavity 10. The cover 92 is welded to the shell 91 to form a welded part 12 that seals the first opening 11. The cover 92 has an inwardly recessed portion 921 on one side in the thickness direction, and the recess 921 communicates with the welded part 12. The sealing structure 13 covers the welded part 12, and at least a portion of the sealing structure 13 is located in the recess 921.

[0094] Electrode assembly 8 is a component in the battery cell 7 where an electrochemical reaction occurs. The housing 9 may contain one or more electrode assemblies 8. Electrode assembly 8 may include an electrode body and tabs. The tabs extend from the side of the electrode body facing the cover 92 and are used to connect to electrode terminals 15 on the cover 92, so that the electrode assembly 8 can be electrically connected to an external electrical device or charging device through the electrode terminals 15.

[0095] The electrode assembly 8 may include a positive electrode, a negative electrode, and a separator. The positive and negative electrodes can serve as the positive and negative electrodes, respectively. During the charging and discharging process of the battery cell 7, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator is stacked between the positive and negative electrodes to isolate them, preventing short circuits while allowing active ions to pass through.

[0096] The outer casing 9 may be a component in the battery cell 7 used to form a sealed space, which is used to house other components such as the electrode assembly 8 in the battery cell 7.

[0097] The housing 91 and the cover 92 are two interconnected parts of the outer shell 9. The housing 91 forms a cavity 10 with one end open, which not only allows the electrode assembly 8 and other components to be placed in the cavity 10, but also allows the electrode assembly 8 and other components to be easily inserted into the cavity 10 through the opening. The cover 92 can be a part used to seal the opening, and its seal fits onto the housing 91 to form a sealed space in the cavity 10.

[0098] The cover 92 is welded to the shell 91 to form a welded part 12, which seals the first opening 11. Alternatively, the cover 92 can be welded to the part of the shell 91 near the first opening 11 and fused together with the shell 91 to form a welded part 12. The welded part 12 seals the gap between the cover 92 and the shell 91, so that the cover 92 seals the first opening 11.

[0099] The cover 92 has an inwardly recessed portion 921 on one side in the thickness direction. This can mean that the cover 92 has an inwardly recessed portion 921 on the side facing the cavity 10, or it can mean that the cover 92 has an inwardly recessed portion 921 on the side away from the cavity 10. The recess 921 can be a structure for providing a receiving space 5c for the material forming the sealing structure 13. By communicating the recess 921 with the welding portion 12, the material containing the material forming the sealing structure 13 in the recess 921 can cover the surface of the welding portion 12 to form the sealing structure 13. At least part of the sealing structure 13 is located in the recess 921, which means that the material used to form the sealing structure 13 occupies the space of the recess 921.

[0100] Exemplarily, the cover 92 has an inwardly recessed portion 921 on the side facing the cavity 10. The material forming the sealing structure 13 contained in the recess 921 can flow to the inner surface of the welded portion 12 facing the cavity 10, forming a sealing structure 13 covering the inner surface of the welded portion 12. Exemplarily, the cover 92 has an inwardly recessed portion 921 on the side away from the cavity 10. The material forming the sealing structure 13 contained in the recess 921 can flow to the outer surface of the welded portion 12 away from the cavity 10, forming a sealing structure 13 covering the outer surface of the welded portion 12.

[0101] The sealing structure 13 can be a structure used to cover the welded part 12 to further seal the gap between the cover 92 and the housing 91. It can continue to cover the welded part 12 and seal the gap between the cover 92 and the housing 91 after the welded part 12 fails, so that the electrolyte of the battery cell 7 is not easy to leak and external impurities are not easy to enter the battery cell 7.

[0102] For example, the sealing structure 13 can be an elastic rubber material that covers the weld portion 12, with part of the elastic rubber material located in the recess 921 and another part protruding from the recess 921. The sealing structure 13 can also be formed of a solid-liquid phase change material that changes from a solid to a fluid liquid state. The solid solid-liquid phase change material can be contained in the recess 921, and when it becomes liquid, it can flow to the surface of the weld portion 12. After becoming solid, it forms a sealing structure 13 covering the surface of the weld portion 12.

[0103] In the above structure, since the sealing structure 13, which is at least partially located in the recess 921, covers the welded portion 12, the sealing structure 13 can seal the welded portion 12. This makes it less likely for the electrolyte of the battery cell 7 to leak after the welded portion 12 fails, and it is also less likely for external impurities to enter the battery cell 7. This improves the reliability of the battery cell 7, and thus helps to improve the reliability of the battery device 2.

[0104] In some embodiments, the sealing structure 13 is located in the cavity 10, and the recess 921 is provided on the side of the cover 92 facing the electrode assembly 8.

[0105] The sealing structure 13 is located in the cavity 10, which means that the sealing structure 13 covers the inner surface of the welded part 12 facing the cavity 10. By placing the sealing structure 13 in the cavity 10, the sealing structure 13 can be protected by the outer shell 9, reducing the possibility of damage such as bumps and knocks, and thus helping to extend the service life of the sealing structure 13.

[0106] By providing a recess 921 on the side of the cover 92 facing the electrode assembly 8, the material containing the recess 921 that forms the sealing structure 13 can flow to the inner surface of the welding part 12 facing the cavity 10, so that the sealing structure 13 is formed in the inner cavity.

[0107] In some embodiments, the sealing structure 13 is a solid-liquid phase change material structure 14.

[0108] The solid-liquid phase change material structure 14 can refer to a structure made of a solid-liquid phase change material. A solid-liquid phase change material can be a material that changes from a solid state to a fluid liquid state when the temperature reaches its melting point. By setting the sealing structure 13 as a solid-liquid phase change material structure 14, during the formation of the sealing structure 13, the solid-liquid phase change material located in the recess 921 can flow from the recess 921 to the surface of the welded portion 12 when the temperature reaches its melting point, so that it can solidify on the surface of the welded portion 12 at a temperature below the melting point to form the sealing structure 13.

[0109] In some embodiments, the melting point of the solid-liquid phase change material is set to T, where 65℃≤T≤160℃.

[0110] By setting the melting point T of the solid-liquid phase change material to a range of 65℃≤T≤160℃, the solid-liquid phase change material can reach its melting point and melt under high-temperature static conditions in the battery cell 7, thus becoming fluid. This allows the solid-liquid phase change material in the recess 921 to flow to the surface of the welding part 12, so that it can solidify on the surface of the welding part 12 to form a sealing structure 13 when the temperature drops. This prevents the battery cell 7 from being subjected to excessively high temperatures to form the sealing structure 13, and also makes the sealing structure 13 less likely to melt due to temperature increases caused by factors such as the heat generated by the battery cell 7.

[0111] Preferably, the melting point T of the solid-liquid phase change material is set to a range of 70℃≤T≤150℃. For example, the melting point T of the solid-liquid phase change material can be set to 70℃, 90℃, 110℃, 130℃ or 150℃. Those skilled in the art can select the melting point of the solid-liquid phase change material according to the actual situation, so that the solid-liquid phase change material can utilize the high temperature of the battery cell 7.

[0112] In some embodiments, the solid-liquid phase change material is a paraffin-like material.

[0113] By setting the solid-liquid phase change material as a paraffin-like material, the solid-liquid phase change material has a suitable melting point, which can meet the conditions for forming the sealing structure 13.

[0114] Paraffin-like materials refer to a class of materials that have similar properties and uses to paraffin. For example, paraffin-like materials that can be used as solid-liquid phase change materials can be one of fully refined paraffin, semi-refined paraffin, crude paraffin, microcrystalline paraffin, and polyethylene wax.

[0115] In some embodiments, reference Figure 6 The recess 921 includes a drain portion 9211 and a receiving portion 9212 that are interconnected. The receiving portion 9212 is connected to the welding portion 12 through the drain portion 9211. The receiving portion 9212 can accommodate solid-liquid phase change material. The drain portion 9211 accommodates a sealing structure 13.

[0116] The draining portion 9211 and the receiving portion 9212 are two interconnected parts within the recess 921. The receiving portion 9212 can be a part capable of containing solid-liquid phase change material, capable of containing the main portion of solid-liquid phase change material, and capable of providing sufficient solid-liquid phase change material for forming the sealing structure 13. The draining portion 9211 can be a part connecting the receiving portion 9212 and the welding portion 12. The receiving portion 9212 is connected to the welding portion 12 through the draining portion 9211, so that the solid-liquid phase change material in the receiving portion 9212 can flow through the draining portion 9211 to the surface of the welding portion 12 to form the sealing structure 13.

[0117] The drainage section 9211 contains a sealing structure 13, which means that after the solid-liquid phase change material flows to the surface of the welding section 12 and solidifies to form a sealing structure 13, part of the sealing structure 13 protrudes into the drainage section 9211 and occupies the space in the drainage section 9211.

[0118] In some embodiments, reference Figure 7 Along the direction of the draining part 9211 toward the welding part 12, the bottom surface of the draining part 9211 continuously approaches the outer surface of the cover 92 relative to the bottom surface of the receiving part 9212.

[0119] The bottom surface of the draining portion 9211 moves closer to the outer surface of the cover 92 relative to the bottom surface of the receiving portion 9212 along the direction of the draining portion 9211 approaching the welding portion 12. This means that the bottom surface of the draining portion 9211 moves closer to the outer surface of the cover 92 relative to the bottom surface of the receiving portion 9212 along the direction of the draining portion 9211 approaching the welding portion 12. This causes the bottom surface of the draining portion 9211 to tilt towards the outer surface of the cover 92 while approaching the welding portion 12. This allows the liquid solid-liquid phase change material to flow towards the welding portion 12 and converge under the action of gravity when the inner surface of the cover 92 is facing upward. This allows the solid-liquid phase change material to flow smoothly to the surface of the welding portion 12, which is convenient for subsequent curing to form a sealing structure 13 covering the welding portion 12.

[0120] For example, the bottom surface of the drainage portion 9211 can be configured as a flat inclined surface that continuously approaches the outer surface of the cover 92 relative to the bottom surface of the receiving portion 9212. The bottom surface of the drainage portion 9211 can also be configured as an arc-shaped inclined surface that continuously approaches the outer surface of the cover 92 relative to the bottom surface of the receiving portion 9212. Those skilled in the art can set it according to the actual situation.

[0121] In some embodiments, reference Figure 8 The angle between the bottom surface of the drainage part 9211 and the bottom surface of the receiving part 9212 is set to A, where 0.5°≤A≤25°.

[0122] When both the bottom surface of the drainage section 9211 and the bottom surface of the receiving section 9212 are flat, the included angle between them is the smaller of a plurality of included angles formed by the two flat surfaces. When one of the bottom surfaces of the drainage section 9211 and the receiving section 9212 is an arc-shaped surface and the other is flat, the included angle between them is the smaller of a plurality of included angles formed by the tangent of the arc-shaped surface and the flat surface. When both the bottom surfaces of the drainage section 9211 and the receiving section 9212 are arc-shaped surfaces, the included angle between them is the smaller of a plurality of included angles formed by the tangents of the two arc-shaped surfaces.

[0123] By setting the range of the included angle A between the bottom surface of the drainage part 9211 and the bottom surface of the receiving part 9212 to 0.5°≤A≤25°, not only can the liquid solid-liquid phase change material flow smoothly to the welding part 12 and converge, but the bottom surface of the drainage part 9211 is also less likely to reduce the thickness of the cover 92 due to the large slope, thereby reducing the weakening of the structural strength of the cover 92 by the recess 921.

[0124] In some embodiments, the included angle A between the bottom surface of the drainage portion 9211 and the bottom surface of the receiving portion 9212 is set to a range of 0.5°≤A≤20°. For example, the included angle A between the bottom surface of the drainage portion 9211 and the bottom surface of the receiving portion 9212 can be set to 0.5°, 5°, 10°, 15° or 20°. This not only allows the liquid solid-liquid phase change material to flow smoothly to the welding portion 12 and converge, but also makes it less likely that the bottom surface of the drainage portion 921 will reduce the thickness of the cover 92 due to the large slope, thereby reducing the weakening of the structural strength of the cover 92 by the recess 921.

[0125] In some embodiments, a plurality of drainage portions 9211 are provided, and the plurality of drainage portions 9211 are arranged at circumferential intervals along the first opening 11.

[0126] By setting multiple drainage portions 9211 spaced circumferentially along the first opening 11, the recess 921 is connected to the welding portion 12 through the multiple drainage portions 9211, which increases the area of ​​communication between the welding portion 12 and the recess 921. This allows the solid-liquid phase change material to cover the welding portion 12 on a larger area to form a sealing structure 13, which is beneficial to improving the sealing effect of the sealing structure 13 on the welding portion 12.

[0127] In some embodiments, reference Figure 9 The recess 921 also includes a seepage portion 9213, which connects two adjacent drainage portions 9211 and is connected to the welding portion 12. The seepage portion 9213 accommodates a sealing structure 13.

[0128] The seepage portion 9213 can be a structure provided in the recess 921 to increase the communication area between the welding portion 12 and the recess 921. By connecting the seepage portion 9213 to two adjacent drainage portions 9211 and to the welding portion 12, the seepage portion 9213 is disposed between the two adjacent drainage portions 9211 and the communication area between the recess 921 and the welding portion 12 is increased, so that the solid-liquid phase change material can cover the welding portion 12 over a larger area to form a sealing structure 13.

[0129] For example, the structure formed by the flow-through portion 9213 and the drainage portion 9211 is connected to the entire weld portion 12 arranged circumferentially along the first opening 11, so that the surface of the entire weld portion 12 can be covered with a sealing structure 13 formed of solid-liquid phase change material.

[0130] In some embodiments, reference Figure 10 The cover 92 is provided with a pressure relief structure 922, and the bottom surface of the receiving part 9212 is provided with a second protrusion 923, which is arranged around the outer periphery of the pressure relief structure 922.

[0131] The pressure relief structure 922 can be a structure for releasing internal gases from the battery cell 7. When the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold, the pressure relief structure 922 activates or a weak structure within it is damaged, thereby creating an opening or channel for releasing internal pressure or temperature. This threshold design varies depending on design requirements. The threshold may depend on the materials of one or more of the positive electrode, negative electrode, electrolyte, and separator in the battery cell 7.

[0132] As an example, the pressure relief structure 922 can be integrally formed with the cover 92.

[0133] As an example, the pressure relief structure 922 can also be separately configured and connected to the housing 9.

[0134] The term "actuation" as used in this application refers to the pressure relief structure 922 being activated or reaching a certain state, thereby releasing the internal pressure and temperature of the battery cell 7. The actions of the pressure relief structure 922 may include, but are not limited to: movement of components within the pressure relief structure 922 to form an exhaust channel, rupture, breakage, tearing, or opening of at least a portion of the pressure relief structure 922, etc. When the pressure relief structure 922 is activated, the high-temperature, high-pressure substances inside the battery cell 7 are discharged outwards from the activated portion. This method allows for pressure and temperature relief of the battery cell 7 under controllable pressure or temperature conditions, thereby preventing potentially more serious accidents.

[0135] The second protrusion 923 can be a structure that protrudes from the bottom surface of the receiving portion 9212. By protruding from the bottom surface of the receiving portion 9212 and surrounding the outer periphery of the pressure relief structure 922, the second protrusion 923 makes it less likely for the solid-liquid phase change material to overflow into the pressure relief structure 922 when it melts in the receiving portion 9212, thereby reducing the impact of the solid-liquid phase change material on the operation of the pressure relief structure 922 and the possibility of leakage from the pressure relief structure 922.

[0136] In some embodiments, the cover 92 is provided with an injection hole 924 extending through the thickness direction, and the bottom surface of the receiving portion 9212 is provided with a third protrusion 925, which surrounds the outer periphery of the injection hole 924.

[0137] The injection hole 924 can be a structure for injecting electrolyte into the cavity 10, and it penetrates the cover 92 along the thickness direction. The third protrusion 925 can be a structure that protrudes from the bottom surface of the receiving portion 9212. By protruding from the bottom surface of the receiving portion 9212 and surrounding the outer periphery of the injection hole 924, the third protrusion 925 is less likely to overflow into the injection hole 924 when the solid-liquid phase change material melts in the receiving portion 9212, thereby reducing the possibility of leakage of the solid-liquid phase change material from the injection hole 924.

[0138] In some embodiments, the cover 92 is provided with an electrode lead-out hole 926 extending through the thickness direction, and the bottom surface of the receiving portion 9212 is provided with a first protrusion 927, which is arranged around the outer periphery of the electrode lead-out hole 926. The battery cell 7 includes an electrode terminal 15 electrically connected to the electrode assembly 8, and a portion of the electrode terminal 15 passes through the electrode lead-out hole 926.

[0139] The electrode terminal 15 may be a component provided on the cover 92 for electrical connection with external electrical devices or charging devices.

[0140] The electrode lead-out hole 926 can be a hole-like structure provided on the cover 92 for setting the electrode terminal 15. It penetrates the cover 92 along the thickness direction, so that the electrode assembly 8 in the cavity 10 can be electrically connected to the external electrical device or charging device through the electrode terminal 15.

[0141] The first protrusion 927 protrudes from the bottom surface of the receiving portion 9212 and surrounds the outer periphery of the electrode lead-out hole 926. This makes it less likely for the solid-liquid phase change material to overflow through the first protrusion 927 and enter the electrode lead-out hole 926 when it melts in the receiving portion 9212, thus reducing the possibility of leakage of the solid-liquid phase change material from the electrode lead-out hole 926.

[0142] In some embodiments, reference Figure 11 The battery cell 7 also includes a first insulating member 16, which is disposed on the side of the cover 92 facing the cavity 10 and covers the recess 921. (See reference) Figures 12 to 14 The electrode terminal 15 includes a first portion 151 and a second portion 152 connected along the thickness direction of the cover 92. At least part of the first portion 151 is located in the electrode lead-out hole 926, and the second portion 152 is located in the cavity 10 and at least part of protrudes from the outer peripheral surface of the first portion 151. A portion of the first insulating member 16 is sandwiched between the first protrusion 927 and the second portion 152.

[0143] The first insulating member 16 may be an insulating member disposed on the side of the cover 92 facing the cavity 10, which is used to insulate and isolate components such as the electrode assembly 8 from the cover 92. The first insulating member 16 disposed on the side of the cover 92 facing the cavity 10 covers the recess 921, so that the recess 921 can form a spatial structure with a second opening 17 (not shown in the figure), so that the solid-liquid phase change material located in the recess 921 can be accommodated by the spatial structure formed by the cover 92 and the first insulating member 16, and the second opening 17 communicates with the welding part 12. Wherein, the accommodating part 9212 and the first insulating member 16 form a space for the solid-liquid phase change material, and the first insulating member 16 and the drainage part 9211 form the second opening 17.

[0144] The first part 151 and the second part 152 can be two interconnected portions of the electrode terminal 15, connected along the thickness direction of the cover 92. The first part 151 is at least partially located within the electrode lead-out hole 926, and the second part 152 is located within the cavity 10. At least a portion of the second part 152 protrudes from the outer peripheral surface of the first part 151, meaning that in the radial direction of the electrode terminal 15, the size of the second part 152 is larger than the size of the first part 151. The first part 151 can extend into the electrode lead-out hole 926, while the second part 152 is located outside the electrode lead-out hole 926 and within the cavity 10.

[0145] A portion of the first insulating member 16 is sandwiched between the first protrusion 927 and the second portion 152. The first insulating member 16, which is located on the side of the cover 92 facing the cavity 10, is sandwiched between the first protrusion 927 and the second portion 152 of the electrode terminal 15, so that the first insulating member 16 can be fixed on the cover 92 under the action of the electrode terminal 15.

[0146] For example, the first part 151 and the second part 152 are integrally formed structures. The first part 151 and the second part 152 can be manufactured by integral forming processing methods such as stamping, so that the first part 151 and the second part 152 can be manufactured as a whole and simultaneously. This not only makes the processing and manufacturing of the first part 151 and the second part 152 convenient, but also gives the overall structure of the first part 151 and the second part 152 good strength. The first part 151 and the second part 152 can also be manufactured by machining methods such as milling, by processing a whole blank.

[0147] In some embodiments, the electrode terminal 15 further includes a third portion 153, which is disposed on the side of the cover 92 away from the cavity 10, and a portion of the first portion 151 extends out from the electrode lead-out hole 926 and is riveted to the third portion 153.

[0148] The third part 153 may be a component of the electrode terminal 15 disposed on the side of the cover 92 away from the cavity 10. The first part 151 is riveted to the third part 153 through the electrode lead-out hole 926. Alternatively, the portion of the first part 151 extending from the electrode lead-out hole 926 may be inserted into the riveting hole of the third part 153 and be forged to form a nail head that abuts against the inner wall of the riveting hole, thereby connecting the first part 151 and the third part 153 and fixing the electrode terminal 15 to the cover 92.

[0149] In some embodiments, the bottom surface of the receiving portion 9212 is provided with a fourth protrusion 928, and a first connecting hole 9281 is formed on the side of the fourth protrusion 928 facing the first insulating member 16. The first insulating member 16 is provided with a first connecting structure, and the first connecting structure is inserted into the first connecting hole 9281.

[0150] The fourth protrusion 928 can be a structure that protrudes from the bottom surface of the receiving portion 9212 toward the first insulating member 16. By providing a first connecting hole 9281 on the side of the fourth protrusion 928 toward the first insulating member 16, providing a first connecting structure on the first insulating member 16, and inserting the first connecting structure into the first connecting hole 9281, the connection force between the first insulating member 16 and the cover 92 can be improved, so that the first insulating member 16 can be more firmly connected to the cover 92.

[0151] In some embodiments, a fifth protrusion 929 is formed on the side of the cover 92 facing the electrode assembly 8, protruding relative to the bottom surface of the recess 921, and the fifth protrusion 929 is connected to the welding portion 12.

[0152] The fifth protrusion 929 can be provided on the side of the cover 92 facing the electrode assembly 8, protruding relative to the bottom surface of the recess 921, and is located between two adjacent drain portions 9211. The fifth protrusion 929 can be formed by the two drain portions 9211 on the cover 92 being recessed inward, so that the fifth protrusion 929 protrudes relative to the bottom surface of the recess 921. Since the drain portion 9211 is connected to the welding portion 12, the fifth protrusion 929 formed between two adjacent drain portions 9211 is connected to the outer peripheral surface of the cover 92 and can be connected to the welding portion 12.

[0153] The fifth protrusion 929 increases the thickness of the cover 92 at this location, thereby increasing the structural strength of the cover 92 at this location and enabling the edge portion of the cover 92 to have sufficient strength to be welded to the shell 91.

[0154] Exemplarily, multiple fifth protrusions 929 are provided, and the multiple fifth protrusions 929 are arranged along the circumference of the cover 92. In some embodiments, the outer circumferential surface of the cover 92 includes multiple side surfaces connected sequentially along the circumference of the cover 92, and the multiple side surfaces are connected end to end to form the outer circumferential surface of the cover 92. The fifth protrusion 929 may be configured to connect with a single side surface of the cover 92, or it may be configured to connect with two connected side surfaces of the cover 92 simultaneously. The fifth protrusion 929 being connected with two connected side surfaces of the cover 92 simultaneously means that the fifth protrusion 929 is connected at the junction of the two connected side surfaces of the cover 92.

[0155] In some embodiments, a second connection hole 9291 is formed on the side of the fifth protrusion 929 facing the first insulating member 16, and the first insulating member 16 is provided with a second connection structure, which is inserted into the second connection hole 9291.

[0156] By providing a second connecting hole 9291 on the side of the fifth protrusion 929 facing the first insulating member 16, providing a second connecting structure on the first insulating member 16, and inserting the second connecting structure into the second connecting hole 9291, the connection force between the first insulating member 16 and the cover 92 can be improved, so that the first insulating member 16 can be more firmly connected to the cover 92.

[0157] For example, there may be multiple fifth protrusions 929, and at least a portion of the multiple fifth protrusions 929 may have a second connection hole 9291.

[0158] For example, the recess 921, the first protrusion 927, the second protrusion 923, the third protrusion 925, the fourth protrusion 928, and the fifth protrusion 929 are all structures formed on the cover 92 by an integral molding process. The recess 921, the first protrusion 927, the second protrusion 923, the third protrusion 925, the fourth protrusion 928, and the fifth protrusion 929 can be made by integral molding methods such as stamping, so that the cover 92 can be manufactured as a whole, which not only makes the manufacturing of the cover 92 convenient, but also gives the overall structure of the cover 92 good strength; the cover 92 can also be made by machining a whole piece of blank using machining methods such as milling.

[0159] In some embodiments, reference Figure 15 Along the circumference of the first opening 11, the size of the drainage part 9211 is set to L, 0.5mm≤L≤55mm.

[0160] By setting the circumferential dimension L of the drainage section 9211 in the first opening 11 to a range of 0.5mm≤L≤55mm, not only does the drainage section 9211 have a sufficiently large communication area with the welding section 12, allowing the liquid solid-liquid phase change material to flow smoothly to the welding section 12, but the drainage section 9211 is also less likely to weaken the structural strength at the edge of the cover 92 due to the excessive circumferential dimension of the first opening 11.

[0161] In some embodiments, the circumferential dimension L of the drainage portion 9211 in the first opening 11 is set to a range of 0.5mm≤L≤50mm. For example, the circumferential dimension of the drainage portion 9211 in the first opening 11 can be set to 0.5mm, 5mm, 15mm, 35mm or 50mm, so that the drainage portion 9211 has a sufficiently large communication area with the welding portion 12 while not easily weakening the structural strength at the edge of the cover 92 due to the excessive circumferential dimension of the first opening 11.

[0162] Some embodiments of this application also provide a battery device 2, which includes the battery cell 7 provided in the above-described technical solution. Because the battery device 2 includes the battery cell 7 provided in the above-described technical solution, the battery device 2 has good reliability.

[0163] In some embodiments, the battery device 2 further includes a housing 5 in which a battery cell 7 is housed, and the orientation of the first opening 11 of the battery cell 7 has a vertically downward component.

[0164] The housing 5 can be a component in the battery device 2 used to house the battery cells 7, which can protect the battery cells 7 and reduce the possibility of damage to them.

[0165] The orientation of the first opening 11 of the battery cell 7 has a vertically downward component, meaning that the first opening 11 of the battery cell 7 is set downwards, allowing the battery cell 7 in the battery device 2 to be inverted. Since the battery cell 7 in the battery device 2 is the battery cell 7 provided by the above-described technical solution, even if the battery cell 7 is inverted, the electrolyte in the battery cell 7 is less likely to leak after the weld portion 12 in the battery cell 7 fails, and external impurities are less likely to enter the battery cell 7, thus improving the reliability of the battery cell 7 and consequently improving the reliability of the battery device 2.

[0166] Some embodiments of this application also provide an electrical device, which includes the battery device 2 provided by the aforementioned technical solution, the battery device 2 being used to provide electrical energy.

[0167] Some embodiments of this application provide a battery cell 7, which includes an electrode assembly 8, a housing 9, and a sealing structure 13. The housing 9 has a shell 91 forming a cavity 10 with a first opening 11. The electrode assembly 8 is disposed in the cavity 10. A cover 92 is welded to the housing 91 to form a welded portion 12 that seals the first opening 11. The cover 92 has an inwardly recessed portion 921 on the side facing the electrode assembly 8. The receiving portion 9212 in the recess 921 can accommodate a solid-liquid phase change material. A drain portion 9211 connects the receiving portion 9212 and the welded portion 12. The sealing structure 13 formed of the solid-liquid phase change material covers the welded portion 12. The drain portion 9211 accommodates the sealing structure 13. Along the direction of the drain portion 9211 near the welded portion 12, the bottom surface of the drain portion 9211 continuously approaches the outer surface of the cover 92 relative to the bottom surface of the receiving portion 9212.

[0168] In the above structure, since the sealing structure 13, which is at least partially located in the recess 921, covers the welded portion 12, the sealing structure 13 can seal the welded portion 12. This makes it less likely for the electrolyte of the battery cell 7 to leak after the welded portion 12 fails, and it is also less likely for external impurities to enter the battery cell 7. This improves the reliability of the battery cell 7, and thus helps to improve the reliability of the battery device 2.

[0169] 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 by, The battery monomer comprises: an electrode assembly; a shell comprising a shell body and a cover body, the shell body forms a cavity with a first opening, the electrode assembly is arranged in the cavity, and the cover body is welded with the shell body to form a welding portion to seal the first opening; the cover body is provided with a recessed portion on one side in the thickness direction, the recessed portion is recessed inward, and the recessed portion is communicated with the welding portion; a sealing structure covers the welding portion, and at least part of the sealing structure is located in the recessed portion.

2. The battery cell of claim 1, wherein, The sealing structure is located in the cavity, and the recessed portion is arranged on the side of the cover body facing the electrode assembly.

3. The battery cell according to claim 1 or 2, characterized in that, The sealing structure is a solid-liquid phase change material structure.

4. The battery cell of claim 3, wherein, The melting point of the solid-liquid phase change material is set as T, and 65℃≤T≤160℃.

5. The battery cell according to claim 3 or 4, characterized in that, The solid-liquid phase change material is a paraffin-like material.

6. The battery cell according to any one of claims 3 to 5, characterized in that, The recessed portion comprises a drainage portion and a containing portion which are communicated with each other, the containing portion is communicated with the welding portion through the drainage portion, the containing portion can contain the solid-liquid phase change material, and the drainage portion contains the sealing structure.

7. The battery cell of claim 6, wherein, In the direction of the drainage portion close to the welding portion, the bottom surface of the drainage portion is continuously close to the outer surface of the cover body relative to the bottom surface of the containing portion.

8. The battery cell of claim 7, wherein, The included angle between the bottom surface of the drainage portion and the bottom surface of the containing portion is set as A, and 0.5°≤A≤25°.

9. The battery cell of any one of claims 6 to 8, wherein, The drainage portion is provided with a plurality of drainage portions which are arranged in the circumferential direction of the first opening.

10. The battery cell of claim 9, wherein, The recessed portion further comprises a seepage portion, the seepage portion is communicated with two adjacent drainage portions and the welding portion, and the seepage portion contains the sealing structure.

11. The battery cell of any one of claims 6 to 10, wherein, The cover body is provided with a pressure relief structure, the bottom surface of the containing portion is provided with a second protrusion, and the second protrusion is arranged around the outer periphery of the pressure relief structure.

12. The battery cell of any one of claims 6 to 11, wherein, The cover body is provided with a liquid injection hole penetrating in the thickness direction, the bottom surface of the containing portion is provided with a third protrusion, and the third protrusion is arranged around the outer periphery of the liquid injection hole.

13. The battery cell of any one of claims 6 to 12, wherein, The cover body is provided with an electrode lead-out hole penetrating in the thickness direction, the bottom surface of the containing portion is provided with a first protrusion, the first protrusion is arranged around the outer periphery of the electrode lead-out hole, and the battery monomer comprises an electrode terminal electrically connected with the electrode assembly, and part of the electrode terminal penetrates the electrode lead-out hole.

14. The battery cell of claim 13, wherein, The battery monomer further comprises a first insulating member, the first insulating member is arranged on the side of the cover body facing the cavity and covers the recessed portion, the electrode terminal comprises a first part and a second part which are connected in the thickness direction of the cover body, at least part of the first part is located in the electrode lead-out hole, the second part is located in the cavity and at least partially protrudes from the outer peripheral surface of the first part, and part of the first insulating member is clamped between the first protrusion and the second part.

15. The battery cell of claim 14, wherein, The electrode terminal further comprises a third part, the third part is arranged on the side of the cover body away from the cavity, and part of the first part extends from the electrode lead-out hole and is riveted to the third part.

16. The battery cell of claim 14 or 15, wherein, The bottom surface of the containing portion is provided with a fourth protrusion, the fourth protrusion is formed with a first connecting hole on the side facing the first insulating member, the first insulating member is provided with a first connecting structure, and the first connecting structure is inserted into the first connecting hole.

17. The battery cell of any one of claims 14 to 16, wherein, A fifth protrusion is formed on a side of the cover body facing the electrode assembly and protruding relative to a bottom surface of the recess, and the fifth protrusion is connected to a welding portion.

18. The battery cell of claim 17, wherein, A second connecting hole is formed on a side of the fifth protrusion facing the first insulating member, and the first insulating member is provided with a second connecting structure that is inserted into the second connecting hole.

19. The battery cell of any one of claims 6 to 18, wherein, The size of the flow guide portion along the circumference of the first opening is L, and 0.5mm≤L≤55mm.

20. A battery device, characterized by The battery cell of any one of claims 1 to 19.

21. The battery device of claim 20, wherein, The battery device further includes a box body in which the battery cell is accommodated, and the first opening of the battery cell faces downward vertically.

22. An electrical device, comprising: The battery device of claim 20 or 21 for providing electrical energy.

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