Battery monomer, battery device and electric equipment

Abstract

The embodiment of the utility model discloses a battery monomer, a battery device and electric equipment, and relates to the field of batteries. The battery monomer comprises a shell, an electrode assembly, lower plastic and an end cover, wherein the shell comprises an opening; the electrode assembly is accommodated in the shell; the lower plastic covers the opening and comprises a protrusion which is located on the side, away from the electrode assembly, of the lower plastic. The end cover is connected with the lower plastic to cover the opening, the end cover comprises a blind hole, the blind hole is located in the side, close to the protrusion, of the end cover, and the blind hole is connected with the protrusion in a clamped mode; wherein the blind hole comprises a first blind hole part and a second blind hole part, the first blind hole part is located on the side, away from the electrode assembly, of the second blind hole part, and the maximum area of the projection, towards the end cover, of the first blind hole part is larger than that of the projection, towards the end cover, of the second blind hole part. The battery monomer can improve the pulling force of the end cover on the lower plastic, and the stability of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical appliance. Background Technology

[0002] Currently, there is a problem that the connection between the internal structures of battery cells is not stable enough. When subjected to external forces such as vibration and impact, components are prone to loosening or separation, which affects the normal use of the battery and may even cause safety hazards. Utility Model Content

[0003] This application provides a battery cell, a battery device, and an electrical appliance that can increase the pulling force of the end cap on the lower plastic and improve the stability of the battery cell.

[0004] In a first aspect, this application provides a battery cell, comprising: a housing, the housing including an opening; an electrode assembly, the electrode assembly being housed in the housing; a lower plastic covering the opening, the lower plastic including a protrusion located on the side of the lower plastic away from the electrode assembly; and an end cap connected to the lower plastic to close the opening, the end cap including a blind hole located on the side of the end cap near the protrusion, the blind hole engaging with the protrusion; wherein the blind hole includes a first blind hole portion and a second blind hole portion, the first blind hole portion being located on the side of the second blind hole portion away from the electrode assembly, and the maximum area of ​​the first blind hole portion projected toward the end cap being greater than the maximum area of ​​the second blind hole portion projected toward the end cap.

[0005] In this embodiment, the blind hole enhances the tensile force on the lower plastic by using a larger first blind hole portion and a smaller second blind hole portion. When the battery is subjected to external forces such as vibration or impact, the difference in cross-sectional area between the first and second blind hole portions allows the blind hole to hold the protrusion in place, increasing the friction and constraint between them, preventing the protrusion from coming out of the blind hole, reducing the possibility of the lower plastic being pulled off, and improving the stability of the battery cell. Furthermore, when the protrusion enters the large-area first blind hole, the first blind hole disperses stress, preventing stress concentration that could damage the connection, further ensuring the stability of the connection between the protrusion and the blind hole.

[0006] In some embodiments of the first aspect, the maximum area of ​​the protrusion projected toward the end cap is less than or equal to the minimum area of ​​the second blind hole portion projected toward the end cap.

[0007] In this embodiment, when the maximum area of ​​the protrusion projected toward the end cap is less than or equal to the minimum area of ​​the second blind hole projected toward the end cap, the protrusion can be easily and accurately aligned with and inserted into the second blind hole during the assembly process of the end cap and the lower plastic. This reduces the possibility that the end cap and the lower plastic cannot be connected due to mismatch between the protrusion and the blind hole, and shortens the assembly time of the end cap and the lower plastic, thereby improving assembly efficiency.

[0008] In some embodiments of the first aspect, the first blind hole portion includes a first end face and a second end face, the first end face being located on the side of the second end face away from the electrode assembly, and the cross-sectional area of ​​the first blind hole portion gradually decreases along the thickness direction of the end cap from the first end face to the second end face.

[0009] In this embodiment, the gradually decreasing cross-sectional area of ​​the first blind hole provides a guiding structure for the protrusion of the lower plastic, facilitating its entry into the first blind hole. When the protrusion is a hot-melt column, the hot-melt column melts upon heating, and the gradually decreasing cross-sectional area provides a backflow slope for the molten hot-melt column. As the hot-melt column gradually melts, the liquid hot-melt material flows along the second end face to the first end face, filling the blind hole. This results in a tight and seamless connection between the hot-melt column and the blind hole after solidification, enhancing the stability of the connection. In this way, the battery cell can have a stable connection structure after assembly, improving the integrity and stability of the battery's internal structure.

[0010] In some embodiments of the first aspect, the blind hole further includes at least one third blind hole portion located between the first blind hole portion and the second blind hole portion, wherein the minimum area of ​​the third blind hole portion projected toward the end cap is greater than the maximum area of ​​the second blind hole portion projected toward the end cap.

[0011] In this embodiment, the third blind hole reinforces the connection structure between the protrusion and the end cap. It forms a "multi-level nested" connection with the second blind hole, similar to the multiple reinforcement designs in a mortise and tenon structure. When the protrusion is connected to the blind hole, the third blind hole provides lateral support to the protrusion and can withstand some of the tensile force on the lower plastic, improving the stability of the connection. When the battery cell is subjected to external forces, this structural design effectively disperses and buffers stress, allowing the stress to be distributed in multiple directions along the contact interface between the blind hole wall and the protrusion. The connection structure composed of the third and second blind holes can adapt to these dynamic changes and maintain the stability of the connection.

[0012] In some embodiments of the first aspect, the minimum area of ​​the first blind hole portion projected toward the end cap is greater than or equal to the maximum area of ​​the third blind hole portion projected toward the end cap.

[0013] In this embodiment, the first blind hole, the third blind hole, and the second blind hole form a stable, cooperative structure through their area relationship. The well-designed areas of the first and third blind holes provide lateral support and stress dispersion. This synergistic effect ensures that the connection structure remains stable even when the end cap and the lower plastic are subjected to external forces from various directions during battery use, reducing the risk of the protrusion detaching from the second blind hole or damage to the blind hole.

[0014] In some embodiments of the first aspect, the blind hole further includes a fourth blind hole portion located on the side of the second blind hole portion away from the first blind hole portion, and the minimum area of ​​the fourth blind hole portion projected toward the end cap is greater than the maximum area of ​​the second blind hole portion projected toward the end cap.

[0015] In this embodiment, since the minimum area of ​​the fourth blind hole portion projected toward the end cap is greater than the maximum area of ​​the second blind hole portion projected toward the end cap, the fourth blind hole portion provides a large initial entry space for the protrusion during assembly, making it easier for the protrusion to enter the blind hole.

[0016] In some embodiments of the first aspect, the end cap includes at least two blind holes, which are evenly distributed near the edge of the end cap.

[0017] In this embodiment, when a battery cell is subjected to external impact, vibration, or pressure, the uniformly distributed blind holes near the edge can evenly disperse stress at the edge of the end cap, effectively preventing stress concentration and improving the end cap's resistance to deformation and the overall structural stability. During assembly, the uniformly distributed blind holes provide positioning references, facilitating the assembly of various structures within the battery cell.

[0018] In some embodiments of the first aspect, the volume of the blind hole is greater than or equal to the volume of the protrusion.

[0019] In this embodiment, the volume of the blind hole is greater than or equal to the volume of the protrusion, allowing the blind hole to accommodate the protrusion and thus enabling a tight connection between the end cap and the lower plastic. A suitable blind hole volume provides more stable support for the protrusion. Furthermore, a suitable volume relationship between the blind hole and the protrusion helps improve the sealing performance of the battery cell. After the protrusion is inserted into the blind hole, a tighter sealing structure can be formed between the two through appropriate manufacturing processes.

[0020] In some embodiments of the first aspect, the projection of the second blind hole toward the end cap is a first circle, the diameter of which is greater than or equal to 2 mm and less than or equal to 4 mm.

[0021] In this embodiment, the diameter of the first circle is within the range of 2-4mm. This ensures a stable connection between the protrusion and the blind hole without compressing or encroaching on the rest of the end cap structure, providing ample space for the layout and normal operation of other end cap components. The protrusion and the second blind hole form a good fit. When the battery is subjected to external forces such as vibration or impact, the appropriate contact area and tight fit effectively disperse stress, preventing the protrusion from detaching from the blind hole and ensuring a stable connection between the end cap and the lower plastic.

[0022] In some embodiments of the first aspect, the projection of the fourth blind hole toward the end cap is a second circle, the diameter of which is greater than or equal to 3 mm and less than or equal to 5 mm.

[0023] In this embodiment, the diameter of the second circle is in the range of 3-5mm, which provides an initial guide space for the protrusion. It also allows for position calibration of the protrusion during the transition to the second blind hole. As the protrusion moves from the fourth blind hole to the second blind hole, due to the difference in their diameters, the protrusion automatically adjusts its position under the gradually decreasing space constraint, improving the accuracy of subsequent assembly.

[0024] In some embodiments of the first aspect, the protrusion includes a conical head and a columnar body, the maximum area of ​​the conical head projected toward the end cap being equal to the area of ​​the columnar body projected toward the end cap.

[0025] In this embodiment, the conical head design provides guidance for the protrusion during assembly. When assembling the lower plastic part and the end cap, the conical head can easily align with the entrance of the blind hole in the end cap, and even if there is a certain positional deviation, the position can be smoothly corrected during insertion. The design that the maximum projected area of ​​the conical head is equal to the projected area of ​​the cylindrical body ensures a smooth transition when inserting into the blind hole, preventing jamming or assembly difficulties caused by abrupt changes in size.

[0026] In some embodiments of the first aspect, in the embodiments of this application, the dimension of the conical head along the thickness direction of the end cap is greater than or equal to 0.3 mm and less than or equal to 0.5 mm.

[0027] In this embodiment, within a size range of 0.3mm-0.5mm, the conical head can better fulfill its guiding function. During assembly, the end with the smaller cross-section can easily align with the entrance of the blind hole in the end cap, and its suitable length and taper facilitate smoother entry of the protrusion into the blind hole.

[0028] In some embodiments of the first aspect, the material of the protrusion includes: polyamide, polycarbonate, polypropylene, or epoxy resin.

[0029] In this embodiment, polyamide, polycarbonate, polypropylene, or epoxy resin is used as the protruding material, which can fill blind holes after melting. With high bonding strength, good mechanical properties, and sealing performance, it enhances connection reliability and the safety of the battery cell. Its hot-melt characteristics are easy to control, and it has high dimensional accuracy after curing or cooling. It is adaptable to different production processes, can efficiently complete the connection operation, and can maintain stable performance under different temperature conditions, thus improving the stability of the battery cell.

[0030] In a second aspect, this application provides a battery device, comprising: a plurality of battery cells; the plurality of battery cells including the battery cells in the first aspect; and a battery housing, in which the plurality of battery cells are housed.

[0031] Thirdly, this application provides an electrical device, including a battery device comprising the battery device of the second aspect, the battery device being used to provide electrical energy.

[0032] In some embodiments, the electrical equipment is a vehicle, a ship, or a spacecraft. Attached Figure Description

[0033] Figure 1 This is a structural diagram of the vehicle according to an embodiment of this application;

[0034] Figure 2 This is a structural diagram of the battery device according to an embodiment of this application;

[0035] Figure 3 This is a structural diagram of a battery cell according to an embodiment of this application;

[0036] Figure 4 This is an exploded view of a single battery cell according to an embodiment of this application;

[0037] Figure 5 This is a structural diagram of the end cap according to an embodiment of this application;

[0038] Figure 6 This is a cross-sectional view of the end cap according to an embodiment of this application;

[0039] Figure 7 This is a partial cross-sectional view of the end cap according to an embodiment of this application;

[0040] Figure 8 This is another partial cross-sectional view of the end cap according to an embodiment of this application;

[0041] Figure 9 This is another partial cross-sectional view of the end cap according to an embodiment of this application;

[0042] Figure 10 This is another partial cross-sectional view of the end cap according to an embodiment of this application;

[0043] Figure 11 This is a structural diagram of the protrusion in an embodiment of this application;

[0044] Figure 12 This is another structural diagram of the protrusion in an embodiment of this application.

[0045] The accompanying drawings are not drawn to scale.

[0046] Figure label:

[0047] 1000 - Vehicle; 100 - Battery assembly; 10 - Battery housing; 101 - First housing section; 102 - Second housing section; 20 - Battery cell; 21 - Housing; 211 - Opening; 22 - End cap; 221 - Blind hole; 2211 - First blind hole section; 2212 - Second blind hole section; 2213 - Third blind hole section; 2214 - Fourth blind hole section; 2215 - First end face; 2216 - Second end face; 23 - Electrode terminal; 24 - Pressure relief mechanism; 25 - Electrode assembly; 251 - Tab; 26 - Lower plastic; 261 - Protrusion; 2611 - Conical head; 2612 - Columnar main body section; 200 - Motor; 300 - Controller. Detailed Implementation

[0048] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0051] In this application, the reference to "embodiment" means that a specific 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 mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0054] 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.

[0055] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0056] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0057] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0058] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0059] 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.

[0060] 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 negative and positive 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, reduces the occurrence of short circuits while allowing active ions to pass through.

[0061] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0062] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0063] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0064] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0065] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0066] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0067] In some embodiments, the battery cell also 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. The electrolyte can be liquid, gel, or solid.

[0068] Liquid electrolytes include electrolyte salts and solvents.

[0069] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid-lithium salt.

[0070] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0071] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0072] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0073] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0074] 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.

[0075] 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.

[0076] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0077] In some embodiments, a pressure relief mechanism is provided on the casing. The pressure relief mechanism is used to release the internal gas of the battery cell.

[0078] As an example, the internal pressure or temperature of a battery cell is actuated to release the internal pressure or temperature when it reaches a predetermined threshold. When the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief mechanism is activated or a weak structure in the pressure relief mechanism is broken, thereby creating an opening or channel for the internal pressure or temperature to be released. The threshold design varies depending on the 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.

[0079] In some embodiments, when the housing is a non-sealed structure, the pressure relief mechanism can be configured as a through hole for venting gas inside the battery cell.

[0080] The emissions from battery cells mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0081] The battery apparatus 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 connected in series, parallel, or mixed connections via a busbar.

[0082] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0083] 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.

[0084] In some embodiments, the battery device may be a battery pack, which includes a battery housing and one or more individual battery cells housed within the battery housing.

[0085] As an example, a battery cell assembly can be a battery module, which can be housed in a battery housing by fixing the battery module in the battery housing.

[0086] As an example, battery cell assemblies can also be housed in a battery housing by directly fixing multiple battery cells to the battery housing.

[0087] As an example, the battery housing may include a first housing section and a second housing section. The first housing section and the second housing section are fastened together to form a closed space inside the battery housing for housing individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing section may be a top cover or a bottom plate.

[0088] As an example, the battery enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, so that the interior of the battery enclosure forms an enclosed space to house individual battery cells.

[0089] In some embodiments, the battery housing may be part of the vehicle's chassis structure. For example, a portion of the battery housing may be at least a part of the vehicle's floor, or a portion of the battery housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0090] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0091] Currently, there is a problem that the connection between the electrode assembly and the casing is not stable enough. When subjected to external forces such as vibration and impact, the components are prone to loosening or separation, which affects the normal use of the battery and may even cause safety hazards.

[0092] Based on the above considerations, this application provides a battery cell that can improve the pulling force of the end cap on the lower plastic and improve the stability of the battery cell. The battery cell provided in this application includes a housing, an electrode assembly, a lower plastic, and an end cap. The housing includes an opening; the electrode assembly is housed within the housing; the lower plastic covers the opening and includes a protrusion located on the side of the lower plastic away from the electrode assembly; the end cap is connected to the lower plastic to close the opening, and the end cap includes a blind hole located on the side of the end cap near the protrusion, the blind hole engaging with the protrusion; wherein the blind hole includes a first blind hole portion and a second blind hole portion, the first blind hole portion being located on the side of the second blind hole portion away from the electrode assembly, and the maximum area of ​​the first blind hole portion projected toward the end cap is greater than the maximum area of ​​the second blind hole portion projected toward the end cap.

[0093] In this type of battery cell, the blind holes, through a larger first blind hole section and a smaller second blind hole section, increase the tensile strength on the lower plastic. When the battery is subjected to external forces such as vibration or impact, the difference in cross-sectional area between the first and second blind hole sections allows the blind holes to hold the protrusion in place, enhancing the friction and constraint between them, preventing the protrusion from coming out of the blind hole, reducing the possibility of the lower plastic being pulled off, and improving the stability of the battery cell. Furthermore, when the protrusion enters the large-area first blind hole section, the first blind hole section disperses stress, preventing stress concentration that could damage the connection, further ensuring the stability of the connection between the protrusion and the blind hole.

[0094] The technical solutions described in this application are applicable to various electrical devices that use battery devices. These electrical devices can be 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.

[0095] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0096] For example, Figure 1 This is a structural diagram of the vehicle according to an embodiment of this application. Figure 1 As shown, vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100, a motor 200, and a controller 300 can be installed inside vehicle 1000. The controller 300 controls the power supply from the battery device 100 to the motor 200. For example, the battery device 100 can be installed at the bottom, front, or rear of vehicle 1000. The battery device 100 can be used to power vehicle 1000; for example, it can serve as the operating power source for vehicle 1000's electrical system, such as for the power requirements of starting, navigation, and operation. In another embodiment of this application, the battery device 100 can not only serve as the operating power source for vehicle 1000 but also as the driving power source, replacing or partially replacing gasoline or natural gas to provide driving force for vehicle 1000.

[0097] Figure 2 This is a structural diagram of a battery device according to an embodiment of this application. Figure 2 As shown, the battery device 100 of this application embodiment may include a plurality of battery cells 20 to meet different power usage needs.

[0098] It should be understood that, such as Figure 2 As shown, the battery device 100 in this embodiment may further include a battery housing 10.

[0099] The battery housing 10 may include two parts, referred to herein as a first housing part 101 and a second housing part 102, which are fastened together. The shapes of the first housing part 101 and the second housing part 102 can be determined according to the shape of the components housed inside, for example, according to the shape of the combination of multiple battery cells 20 housed inside. At least one of the first housing part 101 and the second housing part 102 has an opening. For example, the first housing part 101 and the second housing part 102 may both be hollow cuboids with one face as an opening. The opening 211 of the first housing part 101 and the opening of the second housing part 102 are arranged opposite to each other, and the first housing part 101 and the second housing part 102 are fastened together to form a battery housing 10 with a closed cavity, which can be used to house multiple battery cells 20. Multiple battery cells 20 are connected in parallel, series, or mixed and placed inside the battery housing 10 formed by the fastening of the first housing part 101 and the second housing part 102.

[0100] For example, one of the first housing portion 101 and the second housing portion 102 may be a hollow cuboid with an opening, while the other is plate-shaped to cover the opening. Taking the second housing portion 102 as a hollow cuboid with one opening and the first housing portion 101 as a plate-shaped example, then the first housing portion 101 covers the opening of the second housing portion 102 to form a battery housing 10 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0101] Figure 3 This is a structural diagram of a battery cell according to an embodiment of this application. Figure 4 This is an exploded view of a single battery cell according to an embodiment of this application. Figure 5 This is a structural diagram of the end cap according to an embodiment of this application. Figure 6 This is a cross-sectional view of the end cap according to an embodiment of this application. Figure 7 This is a partial cross-sectional view of the end cap according to an embodiment of this application. Figures 3 to 7 As shown, the battery cell 20 of this embodiment includes a housing 21, an electrode assembly 25, a lower plastic 26, and an end cap 22. The housing 21 includes an opening 211. The electrode assembly 25 is housed in the housing 21. The lower plastic 26 covers the opening 211 and includes a protrusion 261 located on the side of the lower plastic 26 away from the electrode assembly 25. The end cap 22 is connected to the lower plastic 26 to cover the opening 211. The end cap 22 includes a blind hole 221 located on the side of the end cap 22 near the protrusion 261 and engages with the protrusion 261. The blind hole 221 includes a first blind hole portion 2211 and a second blind hole portion 2212. The first blind hole portion 2211 is located on the side of the second blind hole portion 2212 away from the electrode assembly 25. The maximum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0102] In some embodiments, the housing 21 is a hollow structure with an opening 211, and the electrode assembly 25 is housed within the housing 21. The shape of the housing 21 can be determined according to the specific shape of the electrode assembly 25. For example, if the electrode assembly 25 is a cuboid structure, the housing 21 can also be a cuboid structure. Figure 3 and Figure 4 An exemplary case is shown where the housing 21 and electrode assembly 25 are square.

[0103] The shell 21 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not limit this.

[0104] End cap 22 is used to seal opening 211 to form a sealed mounting space for accommodating electrode assembly 25. The mounting space is also used to accommodate electrolyte, such as electrolyte solution.

[0105] The battery cell 20 may also include electrode terminals 23, a pressure relief mechanism 24, and an electrode assembly 25. The electrode terminals 23 are mounted on the end cap 22 and are used to connect with the electrode assembly 25, that is, the electrode terminals 23 are connected to the tabs 251 of the electrode assembly 25.

[0106] The end cap 22 is also equipped with a pressure relief mechanism 24. When the internal pressure of the battery cell 20 rises abnormally, the pressure relief mechanism 24 can be activated in time to release the excessive pressure inside the battery cell 20, thereby reducing the possibility of dangerous situations such as the battery cell 20 exploding.

[0107] In some embodiments, the shape of the battery cell 20 can be flexibly set according to the actual application, that is, the shell 21 of the battery cell 20 can be any polyhedral structure, for example, it can be set as a cuboid or a cylinder.

[0108] In some embodiments, the lower plastic layer 26 serves as an insulating layer between the internal and external environments of the battery cell 20, providing excellent insulation properties. During battery operation, the electrode assembly 25 generates an electric field, and the lower plastic layer 26 prevents current leakage to the outside, thus avoiding short circuits.

[0109] In this embodiment, the lower plastic 26 is flexible, and during the use of the battery device 100, it may be subjected to various external forces, such as vibration and impact. The flexibility of the lower plastic 26 allows it to absorb energy through its own deformation when subjected to these forces, thereby protecting the electrode assembly 25 inside the battery cell 20. The material of the lower plastic 26 may include rubber-like materials or thermoplastic elastomer-like materials.

[0110] In some embodiments, the end cap 22 is connected to the lower plastic 26 to cover the opening 211, i.e., the lower plastic 26 is located between the end cap 22 and the electrode assembly 25.

[0111] In this embodiment of the application, the end cap 22 includes a blind hole 221, which is a non-permeable hole, that is, the blind hole 221 does not penetrate the end cap 22.

[0112] It should be understood that Figure 5 The side of the end cap 22 facing the electrode assembly 25. Figure 6 for Figure 5 Cross-sectional view at point 22A of the middle end cover.

[0113] Specifically, the blind hole 221 is located on the side of the end cap 22 facing the electrode assembly 25, and engages with the protrusion 261 of the lower plastic 26, thereby achieving the connection between the end cap 22 and the lower plastic 26.

[0114] In this embodiment of the application, the blind hole 221 is composed of a first blind hole portion 2211 and a second blind hole portion 2212. The first blind hole portion 2211 is located on the side of the second blind hole portion 2212 away from the electrode assembly 25. That is, when the protrusion 261 is connected to the blind hole 221, it first enters the second blind hole portion 2212 and then enters the first blind hole portion 2211.

[0115] The blind hole 221 engages with the protrusion 261. For example, the shape of the protrusion 261 can be the same as that of the blind hole 221, and the two are tightly connected. That is, when the protrusion 261 is inserted into the blind hole 221, the gap between them is extremely small, and they can fit tightly together. Relative displacement will not easily occur, thus making the connection between the end cap 22 and the lower plastic 26 stable.

[0116] For example, the protrusion 261 can also be interference-fitted with the blind hole 221. That is, the size of the protrusion 261 is slightly larger than the size of the blind hole 221. During assembly, a certain amount of external force is required to press the protrusion 261 into the blind hole 221. During this process, the blind hole 221 will undergo a certain amount of elastic deformation. The pressure and friction generated by the interference fit are extremely large, which can enhance the connection strength between the protrusion 261 and the blind hole 221.

[0117] In this embodiment, the maximum area projected onto the end cap 22 by the first blind hole portion 2211 is greater than the maximum area projected onto the end cap 22 by the second blind hole portion 2212, meaning the cross-sectional area of ​​the first blind hole portion 2211 is greater than the cross-sectional area of ​​the second blind hole portion 2212. For example, the first blind hole portion 2211 can be a cylindrical hole with a larger diameter, while the second blind hole portion 2212 can be a cylindrical hole with a smaller diameter or other shaped hole, forming a stepped structure between them.

[0118] In some embodiments, the area of ​​the first blind hole portion 2211 projected toward the end cap 22 may not be a fixed value, and the area of ​​the second blind hole portion 2212 projected toward the end cap 22 may also not be a fixed value. That is, the first blind hole portion 2211 and the second blind hole portion 2212 may be frustum-shaped, and the maximum area of ​​the former must be greater than the maximum area of ​​the latter.

[0119] For example, the minimum area of ​​the first blind hole portion 2211 projected toward the end cap 22 may be greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22, and the minimum area of ​​the first blind hole portion 2211 projected toward the end cap 22 may be greater than the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0120] For example, the shape of the blind hole 221 can be circular, the diameter of the first blind hole portion 2211 is larger than the diameter of the second blind hole portion 2212, and the protrusion 261 that engages with the blind hole 221 can also be circular.

[0121] It should be understood that the cross-sectional area of ​​the first blind hole 2211 is relatively large. After the protrusion 261 is connected to the blind hole 221, the blind hole 221 can withstand greater tension as the contact area changes, that is, the end cap 22 can withstand greater tension on the lower plastic 26.

[0122] For example, the protrusion 261 on the lower plastic 26 can be a hot melt column, which is a component that achieves a connection function by heating and melting.

[0123] Specifically, when connecting the hot melt column to the blind hole 221, heating equipment must first be prepared. Common heating equipment includes hot air guns, heating plates, and ultrasonic welding equipment. Align the hot melt column with the blind hole 221. Heat the hot melt column using the selected heating equipment. During the heating process, the heating temperature, time, and heating method must be strictly controlled. Excessive temperature may cause the hot melt column to over-melt, flowing to unwanted areas or even damaging the components; insufficient temperature may prevent the hot melt column from melting sufficiently, affecting the bonding effect. During the heating process, the melting state of the hot melt column should be closely observed. When the hot melt column begins to melt, its surface will become smooth and glossy, and gradually soften. After the hot melt column reaches the appropriate melting state, quickly press the lower plastic 26 and the end cap 22 together, so that the molten hot melt column fills the blind hole 221. Maintain constant pressure and allow the molten hot melt column to cool and solidify in the connected state.

[0124] In this embodiment, the blind hole 221 increases the pulling force on the lower plastic 26 through the larger first blind hole portion 2211 and the smaller second blind hole portion 2212. When the battery is subjected to external forces such as vibration or impact, the difference in cross-sectional area between the first blind hole portion 2211 and the second blind hole portion 2212 allows the blind hole 221 to hold the protrusion 261, enhancing the friction and constraint between them, preventing it from coming out of the blind hole 221, reducing the possibility of the lower plastic 26 being pulled off, and improving the stability of the battery cell 20. In addition, when the protrusion 261 enters the large-area first blind hole portion 2211, the first blind hole portion 2211 plays a role in dispersing stress, preventing stress concentration from causing damage to the connection part, and further ensuring the stability of the connection between the protrusion 261 and the blind hole 221.

[0125] In this embodiment of the application, the maximum area of ​​the projection of the protrusion 261 toward the end cap 22 is less than or equal to the minimum area of ​​the projection of the second blind hole portion 2212 toward the end cap 22.

[0126] In some embodiments, the maximum area of ​​the protrusion 261 projected toward the end cap 22 is less than or equal to the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22, that is, the cross-sectional area of ​​the protrusion 261 is less than or equal to the cross-sectional area of ​​the second blind hole portion 2212.

[0127] It should be understood that the area of ​​the projection of the protrusion 261 toward the end cap 22 may not be a fixed value, and the area of ​​the projection of the second blind hole portion 2212 toward the end cap 22 may not be a fixed value. That is, the protrusion 261 and the second blind hole portion 2212 may be frustum-shaped, and the two must satisfy that the maximum value of the former is less than the minimum value of the latter.

[0128] In some embodiments, the maximum area of ​​the protrusion 261 projected toward the end cap 22 can be equal to the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22, or, provided that the end cap 22 and the lower plastic 26 are properly connected, the maximum area of ​​the protrusion 261 projected toward the end cap 22 can be less than the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0129] It should be understood that the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22 is greater than the maximum area of ​​the protrusion 261 projected toward the end cap 22.

[0130] For example, the second blind hole portion 2212 can be cylindrical in shape, and the area projected toward the end cap 22 is a constant.

[0131] In this embodiment, when the maximum area of ​​the protrusion 261 projected toward the end cap 22 is less than or equal to the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22, the protrusion 261 can easily and accurately align with and insert into the second blind hole portion 2212 during the assembly process of the end cap 22 and the lower plastic 26. This reduces the possibility that the end cap 22 and the lower plastic 26 cannot be connected due to the mismatch between the protrusion 261 and the blind hole 221, and shortens the assembly time of the end cap 22 and the lower plastic 26, thereby improving the assembly efficiency.

[0132] Figure 8 This is another partial cross-sectional view of the end cap according to an embodiment of this application. (See attached image.) Figure 8 As shown, the first blind hole portion 2211 includes a first end face 2215 and a second end face 2216. The first end face 2215 is located on the side of the second end face 2216 away from the electrode assembly 25. From the first end face 2215 to the second end face 2216, the cross-sectional area of ​​the first blind hole portion 2211 gradually decreases along the thickness direction of the end cap 22.

[0133] In some embodiments, the first end face 2215 and the second end face 2216 are the end faces of the first blind hole portion 2211 along the thickness direction of the end cap 22, the first end face 2215 is the end face that coincides with the inner wall of the end cap 22, and the second end face 2216 is the end face that is connected to the second blind hole portion 2212.

[0134] It should be understood that the distance from the first end face 2215 to the second end face 2216 is along the thickness direction of the end cover 22 and points towards the electrode assembly 25.

[0135] In some embodiments, from the first end face 2215 to the second end face 2216, the cross-sectional area of ​​the first blind hole portion 2211 gradually decreases along the thickness direction of the end cap 22. For example, both the first end face 2215 and the second end face 2216 are circular, the first blind hole portion 2211 can be frustum shaped, and the first end face 2215 to the second end face 2216 are inclined surfaces; as another example, from the first end face 2215 to the second end face 2216, the first blind hole portion 2211 presents a stepped shape with a gradually decreasing cross-section.

[0136] It should be understood that the first end face 2215 to the second end face 2216 can be a continuous surface.

[0137] For example, the vertical cross-section of the first blind hole portion 2211 can be trapezoidal.

[0138] In this embodiment, the gradually decreasing cross-sectional area of ​​the first blind hole portion 2211 provides a guiding structure for the protrusion 261 of the lower plastic 26, facilitating the protrusion 261's entry into the first blind hole portion 2211. When the protrusion 261 is a hot-melt column, the hot-melt column melts upon heating. The gradually decreasing cross-sectional area provides a backflow slope for the melting hot-melt column. As the hot-melt column gradually melts, the liquid hot-melt material flows along the second end face 2216 to the first end face 2215, filling the blind hole 221. This results in a tight and seamless connection between the hot-melt column and the blind hole 221 after solidification, enhancing the stability of the connection. In this way, the battery cell 20, after assembly, possesses a stable connection structure, improving the integrity and stability of the battery's internal structure.

[0139] Figure 9 This is another partial cross-sectional view of the end cap according to an embodiment of this application. (See attached image.) Figure 9 As shown, the blind hole 221 also includes at least one third blind hole portion 2213, which is located between the first blind hole portion 2211 and the second blind hole portion 2212. The minimum area of ​​the third blind hole portion 2213 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0140] In some embodiments, the third blind hole portion 2213 is located between the first blind hole portion 2211 and the second blind hole portion 2212, and is connected to the first blind hole portion 2211 and the second blind hole portion 2212. That is, when the protrusion 261 is connected to the blind hole 221, the protrusion 261 sequentially enters the second blind hole portion 2212, the third blind hole portion 2213 and the first blind hole portion 2211.

[0141] It should be understood that the blind hole 221 may include a plurality of third blind hole portions 2213, and the plurality of third blind hole portions 2213 are interconnected.

[0142] In this embodiment, the area of ​​the third blind hole portion 2213 projected toward the end cap 22 may not be a fixed value. The third blind hole portion 2213 may be a regular column or approximately frustum-shaped. For example, the third blind hole portion 2213 may be columnar with a vertical and smooth inner wall, which can fit tightly with the protrusion 261; or, for another example, the third blind hole portion 2213 may be approximately frustum-shaped, with its cross-sectional area gradually decreasing from one end near the first blind hole portion 2211 to one end near the second blind hole portion 2212.

[0143] In some embodiments, the minimum area of ​​the third blind hole portion 2213 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22, that is, the cross-sectional area of ​​the third blind hole portion 2213 is greater than the cross-sectional area of ​​the second blind hole portion 2212. For example, the third blind hole portion 2213 can be a cylindrical hole with a larger diameter, and the second blind hole portion 2212 can be a cylindrical hole with a smaller diameter, forming a stepped structure between the two.

[0144] For example, the multiple third blind hole portions 2213 can form multiple stepped structures, maintaining a gradual decrease in cross-sectional area from one end near the first blind hole portion 2211 to one end near the second blind hole portion 2212.

[0145] It should be understood that the cross-sectional area of ​​the third blind hole 2213 is larger. After the protrusion 261 is connected to the blind hole 221, the blind hole 221 can withstand greater tension as the contact area changes, that is, the end cap 22 can withstand greater tension on the lower plastic 26.

[0146] In this embodiment, the third blind hole portion 2213 strengthens the connection structure between the protrusion 261 and the end cap 22. It forms a "multi-level nested" connection with the second blind hole portion 2212, similar to the multiple reinforcement designs in a mortise and tenon structure. When the protrusion 261 is connected to the blind hole 221, the third blind hole portion 2213 provides lateral support to the protrusion 261 and can withstand part of the tensile force on the lower plastic 26, improving the stability of the connection. When the battery cell 20 is subjected to external forces, this structural design effectively disperses and buffers stress, allowing the stress to be dispersed in multiple directions along the contact interface between the blind hole 221 wall and the protrusion 261. The connection structure composed of the third blind hole portion 2213 and the second blind hole portion 2212 can adapt to these dynamic changes and maintain the stability of the connection.

[0147] In this embodiment, the minimum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than or equal to the maximum area of ​​the third blind hole portion 2213 projected toward the end cap 22.

[0148] In some embodiments, the minimum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than or equal to the maximum area of ​​the third blind hole portion 2213 projected toward the end cap 22, that is, the cross-sectional area of ​​the first blind hole portion 2211 is greater than or equal to the cross-sectional area of ​​the third blind hole portion 2213. For example, the first blind hole portion 2211 can be a cylindrical hole with a larger diameter, and the third blind hole portion 2213 can be a cylindrical hole with a smaller diameter, forming a stepped structure between them.

[0149] For example, the first blind hole portion 2211 can be a frustum-shaped structure, and the third blind hole portion 2213 can be a cylindrical structure. The bottom surface of the first blind hole portion 2211 with a larger area coincides with the bottom surface of the third blind hole portion 2213, that is, their shapes and areas are equal.

[0150] In this embodiment, the first blind hole portion 2211, the third blind hole portion 2213, and the second blind hole portion 2212 form a stable structure that works in concert through this area relationship. The reasonable area design of the first blind hole portion 2211 and the third blind hole portion 2213 provides lateral support and stress dispersion. This synergistic effect ensures that the connection structure remains stable when the end cap 22 and the lower plastic 26 are subjected to external forces in various directions during battery use, reducing the risk of the protrusion 261 detaching from the second blind hole portion 2212 or the blind hole 221 being damaged.

[0151] Figure 10 This is another partial cross-sectional view of the end cap according to an embodiment of this application. Figure 10 As shown, the blind hole 221 also includes a fourth blind hole portion 2214, which is located on the side of the second blind hole portion 2212 away from the first blind hole portion 2211. The minimum area of ​​the fourth blind hole portion 2214 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0152] In some embodiments, the fourth blind hole portion 2214 is located on the side of the second blind hole portion 2212 away from the first blind hole portion 2211, that is, the fourth blind hole portion 2214 is connected to the second blind hole portion 2212, that is, when the protrusion 261 is connected to the blind hole 221, the protrusion 261 sequentially enters the fourth blind hole portion 2214, the second blind hole portion 2212, and the first blind hole portion 2211.

[0153] In some embodiments, the blind hole 221 may include a first blind hole portion 2211, a second blind hole portion 2212, a third blind hole portion 2213 and a fourth blind hole portion 2214. That is, when the protrusion 261 is connected to the blind hole 221, the protrusion 261 sequentially enters the fourth blind hole portion 2214, the second blind hole portion 2212, the third blind hole portion 2213 and the first blind hole portion 2211.

[0154] Specifically, the area of ​​the fourth blind hole portion 2214 projected toward the end cap 22 may not be a fixed value. The fourth blind hole portion 2214 may be a regular column or approximately frustum-shaped. For example, the fourth blind hole portion 2214 may be columnar with a vertical and smooth inner wall; as another example, the third blind hole portion 2213 may be approximately frustum-shaped, with its cross-sectional area gradually increasing from one end near the second blind hole portion 2212 to the other end.

[0155] In this embodiment, the minimum area of ​​the fourth blind hole portion 2214 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22, meaning the cross-sectional area of ​​the fourth blind hole portion 2214 is greater than the cross-sectional area of ​​the second blind hole portion 2212. For example, the fourth blind hole portion 2214 can be a cylindrical hole with a larger diameter, and the second blind hole portion 2212 can be a cylindrical hole with a smaller diameter, forming a stepped structure between them.

[0156] In some embodiments, when the maximum area of ​​the protrusion 261 projected toward the end cap 22 is equal to the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22, the minimum area of ​​the fourth blind hole portion 2214 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22, which allows the protrusion 261 to smoothly enter the second blind hole portion 2212.

[0157] In this embodiment, since the minimum area of ​​the fourth blind hole portion 2214 projected toward the end cover 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cover 22, the fourth blind hole portion 2214 provides a large initial entry space for the protrusion 261 during assembly, making it easier for the protrusion 261 to enter the blind hole 221.

[0158] In this embodiment of the application, the end cap 22 includes at least two blind holes 221, which are evenly distributed near the edge of the end cap 22.

[0159] For example, the end cap 22 may include a plurality of blind holes 221, which are evenly distributed.

[0160] It should be understood that the edge of end cap 22 refers to the outermost edge of end cap 22. For example, when end cap 22 is square, the edge of end cap 22 refers to the four sides of end cap 22.

[0161] It should be understood that "near the edge of end cap 22" refers to the outermost part of the surface of end cap 22, near the end cap 22.

[0162] In this embodiment, a plurality of blind holes 221 are evenly distributed near the edge of the end cap 22, meaning that the distance between the plurality of blind holes 221 is equal along the outer side of the end cap 22. For example, the end cap 22 may include two blind holes 221, which may be located near two opposite sides of the end cap 22 and are symmetrically distributed; as another example, the end cap 22 may include four blind holes 221, which may be located near four sides of the end cap 22.

[0163] For example, when the end cap 22 includes an even number of blind holes 221, the blind holes 221 can be distributed in an axisymmetric manner.

[0164] In this embodiment, for the inverted electrode assembly 25 inside the battery cell 20, to prevent the lower plastic 26 from affecting the function of the pressure relief mechanism 24, there is no connection structure between the lower plastic 26 and the end cap 22. In this case, the blind holes 221 distributed around the end cap 22 bear the tension on the lower plastic 26.

[0165] In this embodiment, when the battery cell 20 is subjected to external impact, vibration, or pressure, the blind holes 221 evenly distributed near the edge can evenly disperse the stress at the edge of the end cap 22, effectively avoiding stress concentration and improving the deformation resistance of the end cap 22 and the stability of the overall structure. During assembly, the evenly distributed blind holes 221 provide positioning references, facilitating the assembly of various structures of the battery cell 20.

[0166] In this embodiment of the application, the volume of the blind hole 221 is greater than or equal to the volume of the protrusion 261.

[0167] It should be understood that the volume of blind hole 221 is the sum of the volumes of each blind hole 221.

[0168] In some embodiments, provided that the end cap 22 and the lower plastic 26 are tightly connected, the volume of the blind hole 221 can be larger than the volume of the protrusion 261.

[0169] In some embodiments, the larger volume of the blind hole 221 allows the blind hole 221 to have enough space to accommodate the protrusion 261, so that even if there is slight shaking or displacement during insertion, it is not easy to cause wear or cracking of the protrusion 261 or the wall of the blind hole 221.

[0170] In this embodiment, the volume of the blind hole 221 is greater than or equal to the volume of the protrusion 261, allowing the blind hole 221 to accommodate the protrusion 261, thereby enabling a tight connection between the end cap 22 and the lower plastic 26. A suitable volume of the blind hole 221 provides more stable support for the protrusion 261. Furthermore, a suitable volume relationship between the blind hole 221 and the protrusion 261 helps improve the sealing performance of the battery cell 20. After the protrusion 261 is inserted into the blind hole 221, a tighter sealing structure can be formed between the two through a reasonable process.

[0171] In this embodiment of the application, the projection of the second blind hole portion 2212 toward the end cap 22 is a first circle, and the diameter of the first circle is greater than or equal to 2mm and less than or equal to 4mm.

[0172] It should be understood that the projection of the second blind hole portion 2212 toward the end cap 22 is a first circle, that is, the cross-section of the second blind hole portion 2212 is a circle.

[0173] For example, the second blind hole portion 2212 can be frustum-shaped or cylindrical.

[0174] In this embodiment of the application, the cross-sectional diameter of the second blind hole portion 2212 is greater than or equal to 2 mm and less than or equal to 4 mm.

[0175] In some embodiments, the diameter of the first circle may be greater than or equal to 2.5 mm and less than or equal to 3.5 mm.

[0176] In some embodiments, the diameter of the first circle is 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, or 4mm.

[0177] In this embodiment, the diameter of the first circle is within the range of 2-4 mm. This ensures a stable connection between the protrusion 261 and the blind hole 221 without compressing or encroaching on the rest of the end cap 22, providing ample space for the layout and normal operation of other components of the end cap 22. The protrusion 261 and the second blind hole 2212 form a good fit. When the battery is subjected to external forces such as vibration or impact, the appropriate contact area and tight fit effectively disperse stress, preventing the protrusion 261 from detaching from the blind hole 221, thus ensuring a stable connection between the end cap 22 and the lower plastic 26.

[0178] In this embodiment of the application, the projection of the fourth blind hole portion 2214 toward the end cap 22 is a second circle, and the diameter of the second circle is greater than or equal to 3mm and less than or equal to 5mm.

[0179] It should be understood that the projection of the fourth blind hole portion 2214 toward the end cap 22 is a second circle, that is, the cross-section of the fourth blind hole portion 2214 is a circle.

[0180] For example, the fourth blind hole portion 2214 can be frustum-shaped or cylindrical.

[0181] In this embodiment of the application, the cross-sectional diameter of the fourth blind hole portion 2214 is greater than or equal to 3 mm and less than or equal to 5 mm.

[0182] In some embodiments, the diameter of the first circle may be greater than or equal to 3.5 mm and less than or equal to 4.5 mm.

[0183] In some embodiments, the diameter of the first circle is 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, or 5mm.

[0184] It should be understood that the fourth blind hole portion 2214 is connected to the second blind hole portion 2212, and its function is to allow the protrusion 261 to smoothly enter the second blind hole portion 2212. Therefore, the diameter of the second circle needs to be larger than that of the first circle.

[0185] In this embodiment, the diameter of the second circle is in the range of 3-5 mm, which provides an initial guide space for the protrusion 261. It also allows for position calibration of the protrusion 261 during the transition to the second blind hole portion 2212. As the protrusion 261 moves from the fourth blind hole portion 2214 to the second blind hole portion 2212, due to the difference in their diameters, the protrusion 261 automatically adjusts its position under the gradually decreasing space constraint, improving the accuracy of subsequent assembly.

[0186] Figure 11 This is a structural diagram of the protrusion in an embodiment of this application. Figure 12 This is another structural diagram of the protrusion in an embodiment of this application. (See diagram below.) Figure 11 and Figure 12 As shown, the protrusion 261 includes a conical head 2611 and a columnar body 2612. The maximum area of ​​the conical head 2611 projected toward the end cap 22 is equal to the area of ​​the columnar body 2612 projected toward the end cap 22.

[0187] In some embodiments, when the projection of the blind hole 221 toward the end cap 22 is circular, the projection of the corresponding protrusion 261 toward the end cap 22 can also be circular.

[0188] In some embodiments, the maximum area of ​​the conical head 2611 projected toward the end cap 22 is equal to the area of ​​the columnar body 2612 projected toward the end cap 22, that is, the diameter of the bottom surface of the conical head 2611 is equal to the diameter of the bottom surface of the columnar body.

[0189] For example, the cone-shaped head 2611 can be a vertebral body, such as Figure 12 As shown; it can also be in the shape of a frustum, such as Figure 11 As shown, the larger bottom surface of the frustum coincides with the bottom surface of the columnar main body 2612.

[0190] It should be understood that the maximum area of ​​the columnar head facing the end cap 22 can be smaller than the area of ​​the columnar body 2612 projected toward the end cap 22.

[0191] In this embodiment of the application, when the protrusion 261 is connected to the blind hole 221, the conical head 2611 enters the blind hole 221 first, and the columnar body 2612 enters the blind hole 221 afterward.

[0192] In some embodiments, in order to ensure that the protrusion 261 fits tightly with the blind hole 221, the area of ​​the columnar main body portion 2612 projected toward the end cap 22 can be the same as the area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0193] In this embodiment, the conical head 2611 provides guidance for the protrusion 261 during assembly. When assembling the lower plastic 26 with the end cap 22, the conical head 2611 can easily align with the entrance of the blind hole 221 on the end cap 22. Even if there is a certain positional deviation, the position can be smoothly corrected during insertion. The design that the maximum projected area of ​​the conical head 2611 is equal to the projected area of ​​the cylindrical body 2612 ensures a smooth transition when inserting into the blind hole 221, preventing jamming or assembly difficulties caused by abrupt changes in size.

[0194] In this embodiment of the application, the dimension of the conical head 2611 along the thickness direction of the end cap 22 is greater than or equal to 0.3 mm and less than or equal to 0.5 mm.

[0195] It should be understood that the dimension of the conical head 2611 along the thickness direction of the end cap 22 is the height of the conical head 2611.

[0196] In some embodiments, the shape of the conical head 2611 does not have to be a strictly defined cone. It is only necessary to keep it pointing towards the blind hole 221 along the thickness direction of the end cap 22, and the cross-section of the conical head 2611 gradually decreases.

[0197] In some embodiments, if the conical head 2611 is too small in size along the thickness direction of the end cap 22, its guiding function will be greatly reduced during assembly. The protrusion 261 will have difficulty quickly and accurately entering the blind hole 221 of the end cap 22, increasing assembly difficulty and time, and thus reducing production efficiency. At the same time, the excessively small size will result in poor initial contact and stress dispersion between the protrusion 261 and the blind hole 221 when subjected to external force, making the connection easy to loosen and affecting the normal operation of the battery.

[0198] In this embodiment, if the size of the conical head 2611 along the thickness direction of the end cap 22 is too large, the height of the columnar body 2612 will be too small due to the limited volume of the protrusion 261. This may result in the protrusion 261 not being tightly connected to the blind hole 221 when it is inserted into the blind hole 221, or being unable to be fully inserted into the blind hole 221, which is not conducive to the assembly and long-term stable use of the battery cell 20.

[0199] In this embodiment, within a size range of 0.3mm-0.5mm, the conical head 2611 can better perform its guiding function. During assembly, the end with the smaller cross-section can easily align with the entrance of the blind hole 221 on the end cap 22. With its suitable length and taper, the protrusion 261 can more smoothly enter the blind hole 221.

[0200] In this embodiment, the material of the protrusion 261 includes: polyamide, polycarbonate, polypropylene, or epoxy resin.

[0201] It should be understood that polyamide has good mechanical properties, including high strength and toughness. It can withstand a certain degree of tension, bending, and impact, which makes the protrusion 261 less prone to breakage under external force. Its melting point is usually between 200-300℃. When the temperature reaches the melting point range, the polyamide can melt rapidly and uniformly, allowing the protrusion 261 to quickly and stably fill the blind hole 221 during the connection process, achieving a tight bond between the lower plastic 26 and the end cap 22.

[0202] It should be understood that polycarbonate has good thermal stability and can maintain stable performance over a wide temperature range, with a melting point generally around 220-250℃. During the heating and melting process of protrusion 261, it can maintain a stable liquid state over a wide temperature range and is not prone to decomposition or carbonization. After melting, polycarbonate can rapidly cool and solidify when the temperature drops. Rapid cooling and solidification allows protrusion 261 to quickly set, reducing deformation or displacement that may occur due to prolonged liquid state, thus ensuring the accuracy and stability of the connection.

[0203] It should be understood that polypropylene has a low density and is a lightweight material. Its melting point is approximately between 160-170℃. This low melting point means that less energy is required during the heating process of the hot melt column, reducing energy costs in the manufacturing process. Molten polypropylene possesses good melt strength, allowing it to maintain a certain shape when filling the blind holes 221 on the end cap 22, preventing flow or collapse. This ensures the accuracy and stability of the connection during the hot melt column connection process.

[0204] It should be understood that epoxy resin has excellent bonding properties and can firmly bond with a variety of materials. After curing, it forms a highly cross-linked three-dimensional network structure with high hardness and strength, while also exhibiting good chemical resistance and electrical insulation. The curing process of epoxy resin usually requires the use of a curing agent, and the curing temperature varies depending on the formulation, generally ranging from 80-150℃.

[0205] In this embodiment, polyamide, polycarbonate, polypropylene, or epoxy resin is used as the material for the protrusion 261. After melting, it can fill the blind holes 221, enhancing connection reliability and the safety of the battery cell 20 due to its high bonding strength, good mechanical properties, and sealing performance. Its hot-melt characteristics are easy to control, and it has high dimensional accuracy after curing or cooling. It is adaptable to different production processes, can efficiently complete the connection operation, and can maintain stable performance under different temperature conditions, thus improving the stability of the battery cell 20.

[0206] According to some embodiments of this application, this application also provides a battery device 100, which includes a plurality of battery cells 20 and a battery housing 10, wherein the plurality of battery cells 20 are housed in the battery housing 10. The battery cell 20 includes a housing 21, an electrode assembly 25, a lower plastic 26, and an end cap 22. The housing 21 includes an opening 211. The electrode assembly 25 is housed in the housing 21. The lower plastic 26 covers the opening 211 and includes a protrusion 261 located on the side of the lower plastic 26 away from the electrode assembly 25. The end cap 22 is connected to the lower plastic 26 to close the opening 211. The end cap 22 includes a blind hole 221 located on the side of the end cap 22 near the protrusion 261 and engages with the protrusion 261. The blind hole 221 includes a first blind hole portion 2211 and a second blind hole portion 2212. The first blind hole portion 2211 is located on the side of the second blind hole portion 2212 away from the electrode assembly 25. The maximum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0207] It should be understood that the battery cell 20 may also be the battery cell 20 of any of the above embodiments.

[0208] In this embodiment, the battery housing 10 may be made of one or more materials. For example, it may include high-strength metallic materials, such as aluminum alloys or steel, to provide good structural strength and stability and ensure the safety of the battery in various environments; it may also include non-metallic materials with excellent insulation properties, such as engineering plastics, to reduce the possibility of safety hazards such as battery leakage; and it may also include materials with good thermal conductivity to facilitate heat dissipation during battery operation and maintain the normal operating temperature of the battery.

[0209] According to some embodiments of this application, this application also provides an electrical device, which includes a battery device 100 for providing electrical energy. The battery device 100 includes a plurality of battery cells 20, each battery cell 20 including a housing 21, an electrode assembly 25, a lower plastic 26, and an end cap 22. The housing 21 includes an opening 211; the electrode assembly 25 is housed within the housing 21; the lower plastic 26 covers the opening 211, and the lower plastic 26 includes a protrusion 261 located on the side of the lower plastic 26 away from the electrode assembly 25; the end cap 22 is connected to the lower plastic 26 to close the opening 211. 2 includes a blind hole 221, which is located on the side of the end cap 22 near the protrusion 261 and is engaged with the protrusion 261; wherein, the blind hole 221 includes a first blind hole portion 2211 and a second blind hole portion 2212, the first blind hole portion 2211 is located on the side of the second blind hole portion 2212 away from the electrode assembly 25, and the maximum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0210] It should be understood that the battery cell 20 may also be the battery cell 20 of any of the above embodiments.

[0211] According to some embodiments of this application, see Figures 3 to 12 This application provides a battery cell 20, which includes a housing 21, an electrode assembly 25, a lower plastic 26, and an end cap 22. The housing 21 includes an opening 211. The electrode assembly 25 is housed in the housing 21. The lower plastic 26 covers the opening 211 and includes a protrusion 261 located on the side of the lower plastic 26 away from the electrode assembly 25. The end cap 22 is connected to the lower plastic 26 to cover the opening 211. The end cap 22 includes a blind hole 221 located on the side of the end cap 22 near the protrusion 261 and engages with the protrusion 261. The blind hole 221 includes a first blind hole portion 2211 and a second blind hole portion 2212. The first blind hole portion 2211 is located on the side of the second blind hole portion 2212 away from the electrode assembly 25. The maximum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22. The maximum area of ​​the protrusion 261 projected toward the end cap 22 is less than or equal to the minimum area of ​​the second blind hole portion 2212 projected toward the end cap 22. The first blind hole portion 2211 includes a first end face 2215 and a second end face 2216. The first end face 2215 is located on the side of the second end face 2216 away from the electrode assembly 25. From the first end face 2215 to the second end face 2216, the cross-sectional area of ​​the first blind hole portion 2211 gradually decreases along the thickness direction of the end cap 22.

[0212] The blind hole 221 also includes at least one third blind hole portion 2213 and a fourth blind hole portion 2214. The third blind hole portion 2213 is located between the first blind hole portion 2211 and the second blind hole portion 2212. The minimum area of ​​the third blind hole portion 2213 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22. The minimum area of ​​the first blind hole portion 2211 projected toward the end cap 22 is greater than the maximum area of ​​the third blind hole portion 2213 projected toward the end cap 22. The fourth blind hole portion 2214 is located on the side of the second blind hole portion 2212 away from the first blind hole portion 2211. The minimum area of ​​the fourth blind hole portion 2214 projected toward the end cap 22 is greater than the maximum area of ​​the second blind hole portion 2212 projected toward the end cap 22.

[0213] The end cap 22 includes at least two blind holes 221, which are evenly distributed near the edge of the end cap 22. The volume of each blind hole 221 is greater than or equal to the volume of the protrusion 261. The projection of the second blind hole portion 2212 toward the end cap 22 is a first circle, the diameter of which is greater than or equal to 2 mm and less than or equal to 4 mm. The projection of the fourth blind hole portion 2214 toward the end cap 22 is a second circle, the diameter of which is greater than or equal to 3 mm and less than or equal to 5 mm.

[0214] The protrusion 261 includes a conical head 2611 and a cylindrical body 2612. The maximum area of ​​the conical head 2611 projected toward the end cap 22 is equal to the area of ​​the cylindrical body 2612 projected toward the end cap 22. The dimension of the conical head 2611 along the thickness direction of the end cap 22 is greater than or equal to 0.3 mm and less than or equal to 0.5 mm. The material of the protrusion 261 includes polyamide, polycarbonate, polypropylene, or epoxy resin.

[0215] 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: A housing (21), the housing (21) including an opening (211); Electrode assembly (25), the electrode assembly (25) being housed in the housing (21); A lower plastic (26) that covers the opening (211) includes a protrusion (261) located on the side of the lower plastic (26) away from the electrode assembly (25). End cap (22), the end cap (22) is connected to the lower plastic (26) to cover the opening (211), the end cap (22) includes a blind hole (221), the blind hole (221) is located on the side of the end cap (22) near the protrusion (261), the blind hole (221) engages with the protrusion (261); The blind hole (221) includes a first blind hole portion (2211) and a second blind hole portion (2212). The first blind hole portion (2211) is located on the side of the second blind hole portion (2212) away from the electrode assembly (25). The maximum area of ​​the first blind hole portion (2211) projected toward the end cap (22) is greater than the maximum area of ​​the second blind hole portion (2212) projected toward the end cap (22).

2. The battery cell according to claim 1, characterized in that, The maximum area of ​​the protrusion (261) projected toward the end cap (22) is less than or equal to the minimum area of ​​the second blind hole portion (2212) projected toward the end cap (22).

3. The battery cell according to claim 1, characterized in that, The first blind hole portion (2211) includes a first end face (2215) and a second end face (2216). The first end face (2215) is located on the side of the second end face (2216) away from the electrode assembly (25). From the first end face (2215) to the second end face (2216), the cross-sectional area of ​​the first blind hole portion (2211) gradually decreases along the thickness direction of the end cap (22).

4. The battery cell according to claim 3, characterized in that, The blind hole (221) further includes at least one third blind hole portion (2213), which is located between the first blind hole portion (2211) and the second blind hole portion (2212). The minimum area of ​​the third blind hole portion (2213) projected toward the end cap (22) is greater than the maximum area of ​​the second blind hole portion (2212) projected toward the end cap (22).

5. The battery cell according to claim 4, characterized in that, The minimum area of ​​the first blind hole portion (2211) projected toward the end cap (22) is greater than or equal to the maximum area of ​​the third blind hole portion (2213) projected toward the end cap (22).

6. The battery cell according to claim 4, characterized in that, The blind hole (221) further includes a fourth blind hole portion (2214), which is located on the side of the second blind hole portion (2212) away from the first blind hole portion (2211). The minimum area of ​​the fourth blind hole portion (2214) projected toward the end cap (22) is greater than the maximum area of ​​the second blind hole portion (2212) projected toward the end cap (22).

7. The battery cell according to any one of claims 1 to 6, characterized in that, The end cap (22) includes at least two blind holes (221), which are evenly distributed near the edge of the end cap (22).

8. The battery cell according to any one of claims 1 to 6, characterized in that, The volume of the blind hole (221) is greater than or equal to the volume of the protrusion (261).

9. The battery cell according to any one of claims 1 to 6, characterized in that, The projection of the second blind hole portion (2212) toward the end cap (22) is a first circle, the diameter of which is greater than or equal to 2 mm and less than or equal to 4 mm.

10. The battery cell according to claim 6, characterized in that, The projection of the fourth blind hole portion (2214) toward the end cap (22) is a second circle, the diameter of which is greater than or equal to 3 mm and less than or equal to 5 mm.

11. The battery cell according to claim 9, characterized in that, The protrusion (261) includes a conical head (2611) and a columnar body (2612), and the maximum area of ​​the conical head (2611) projected toward the end cap (22) is equal to the area of ​​the columnar body (2612) projected toward the end cap (22).

12. The battery cell according to claim 11, characterized in that, The dimension of the conical head (2611) along the thickness direction of the end cap (22) is greater than or equal to 0.3 mm and less than or equal to 0.5 mm.

13. The battery cell according to claim 11, characterized in that, The material of the protrusion (261) includes: polyamide, polycarbonate, polypropylene or epoxy resin.

14. A battery device, characterized in that, include: Multiple battery cells; the multiple battery cells include the battery cells according to any one of claims 1 to 13; A battery housing (10) in which the plurality of battery cells are housed.

15. An electrical appliance, characterized in that, include: A battery device, comprising the battery device according to claim 14, the battery device being used to provide electrical energy.

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