Battery cell, battery device, and electric device

Abstract

This application discloses a battery cell, a battery device, and an electrical appliance. The battery cell includes a casing, an electrode assembly, a first electrode terminal, and a first conductive component. The casing includes a wall portion with a first electrode lead-out hole. The electrode assembly is housed within the casing and includes a main body portion and a first tab extending from the main body portion. The first electrode terminal is located at the first electrode lead-out hole and is insulated from the wall portion, forming a first insulating gap between the first electrode terminal and the wall portion. The first conductive component is connected to the first electrode terminal and is insulated from the wall portion, with at least a portion of the first conductive component exposed in the first insulating gap. The melting point of the first conductive component is lower than that of the first electrode terminal. When an external short circuit occurs in the battery cell, the first conductive component rapidly melts and fills the first insulating gap, connecting the first electrode terminal and the wall portion, melting off the current-carrying component, which helps reduce the risk of battery cell fire and explosion and improves the reliability of the battery cell.

Description

Technical Field

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

[0002] With the development of new energy technologies, batteries are being used more and more widely. For example, batteries 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 military equipment and aerospace and many other fields.

[0003] The development of battery technology must take into account multiple design factors, such as energy density, cycle life, assembly efficiency, and processing technology, as well as battery reliability. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical appliance, which helps to improve the reliability of the battery cell.

[0005] According to a first aspect of this application, a battery cell is provided, comprising a housing, an electrode assembly, a first electrode terminal, and a first conductive component. The housing includes a wall portion with a first electrode lead-out hole. The electrode assembly is housed within the housing and includes a main body portion and a first tab extending from the main body portion. The first electrode terminal is disposed at the first electrode lead-out hole and is insulated from the wall portion, forming a first insulating gap between the first electrode terminal and the wall portion. The first conductive component is connected to the first electrode terminal and is insulated from the wall portion, with at least a portion of the first conductive component exposed within the first insulating gap. The melting point of the first conductive component is lower than the melting point of the first electrode terminal. When an external short circuit occurs in the battery cell, the first electrode terminal heats up, rapidly melting the first conductive component. The melted first conductive component fills at least a portion of the space in the first insulating gap, thereby connecting the first electrode terminal and the wall portion. The wall can directly connect the positive and negative terminals of the battery cell, which can reduce short-circuit resistance, increase short-circuit current, and melt some overcurrent components in the current circuit (such as adapters, tabs, etc.), which helps to reduce the risk of battery cell fire and explosion and improve the reliability of battery cell.

[0006] In some embodiments, at least a portion of the first insulating gap is located between the first conductive component and the wall portion along the arrangement direction of the first conductive component and the wall portion. This shortens the distance the molten first conductive component travels to the wall portion, improves the efficiency of the first conductive component in connecting the wall portion and the first electrode terminal, and facilitates the rapid melting of some overcurrent components in the current circuit, thereby further reducing the risk of battery cell fire and explosion.

[0007] In some embodiments, the first insulation gap is an annular gap extending circumferentially along the first electrode terminal. This increases the current-carrying area between the first electrode terminal and the wall, thereby reducing short-circuit resistance, increasing short-circuit current, and facilitating faster melting of some current-carrying components in the current loop, thus reducing the risk of battery cell fire and explosion.

[0008] In some embodiments, the first conductive component is an annular component extending circumferentially along the first electrode terminal. When heated, the first conductive component can flow more quickly and evenly into the annular first insulating gap, which helps to shorten the time it takes for the first conductive component to conduct electricity between the first electrode terminal and the wall, shorten the duration of the external short circuit of the battery cell, and reduce the risk of the battery cell catching fire or exploding.

[0009] In some embodiments, the volume of the first conductive component is larger than the volume of the first insulating gap. After melting, the first conductive component can fill the first insulating gap, more reliably connecting the wall and the first electrode terminal. Furthermore, it can increase the current-carrying area between the wall and the first electrode terminal, reducing short-circuit resistance and increasing short-circuit current, which facilitates faster melting of the current-carrying components in the current loop. In some embodiments, at least a portion of the first electrode terminal is housed in the first electrode lead-out hole, and the first insulating gap is located between the first electrode terminal and the hole wall of the first electrode lead-out hole; the first conductive component is housed in the first insulating gap. The portion of the first electrode terminal housed in the first electrode lead-out hole has a larger current flow, generates more heat, and has a relatively higher temperature. When an external short circuit occurs in the battery cell, the first conductive component is more easily melted, which facilitates faster connection between the first electrode terminal and the wall, reducing the risk of battery cell fire and explosion. Moreover, regardless of whether the battery cell is placed upright or inverted, the molten first conductive component can connect the wall and the first electrode terminal, making it widely applicable.

[0010] In some embodiments, the first conductive component is disposed around the first electrode terminal, and the inner peripheral surface of the first conductive component is attached to the outer peripheral surface of the first electrode terminal. The first conductive component does not occupy the current-carrying space of the first electrode terminal, which helps to increase the current-carrying area of ​​the first electrode terminal and improve its current-carrying capacity. Simultaneously, it also helps to shorten the distance between the first conductive component and the wall, reducing the required volume of the first conductive component and saving costs.

[0011] In some embodiments, along the thickness direction of the wall, the two ends of the first conductive component are flush with the two ends of the first insulating gap; the volume of the first conductive component is V1, and the volume of the insulating gap is V0, 0.3≤V1 / V0≤0.8, optionally, 0.5≤V1 / V0≤0.7. When V1 / V0 is greater than or equal to 0.3, the volume of the first conductive component relative to the first insulating gap is not too small. After the first conductive component melts, it can at least fill the bottom space of the first insulating gap along the direction of gravity, thereby effectively connecting the wall and the first electrode terminal. Furthermore, the current-carrying area of ​​the first conductive component is not too small, which is beneficial for increasing the short-circuit current and improving the efficiency of the current-carrying component's melting. When V1 / V0 is less than or equal to 0.8, under normal use of the battery cell, the space not occupied by the first conductive component in the first insulating gap is not too small, allowing for a relatively large gap to be formed between the first conductive component and the wall, which helps reduce the risk of the first conductive component and the wall becoming connected due to assembly errors.

[0012] In some embodiments, the first electrode terminal includes a first terminal portion and a second terminal portion. At least a portion of the first terminal portion is accommodated in a first electrode lead-out hole, and the second terminal portion protrudes from the outer peripheral surface of the first terminal portion. Along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion. The battery cell includes a seal, a portion of which is sandwiched between the wall portion and the second terminal portion along the thickness direction of the wall portion. Along the direction from the main body portion to the wall portion, the seal covers the first insulating gap. The seal forms a portion enclosing the first insulating gap, which can reduce the risk of the first conductive component in a molten state flowing out of the first insulating gap, which helps to save the volume required for the first conductive component and improve the efficiency of the first conductive component in a molten state in conducting the first electrode terminal and the wall portion.

[0013] In some embodiments, the melting point of the first conductive component is lower than that of the seal. When an external short circuit occurs in the battery cell, the first conductive component can melt preferentially before the seal, thereby promptly connecting the first electrode terminal and the wall, and then melting the overcurrent component to disconnect the current circuit of the battery cell. This helps to reduce the risk of sealing failure of the battery cell before the current circuit is disconnected, and improves the reliability of the battery cell.

[0014] In some embodiments, the first electrode terminal includes a first terminal portion and a second terminal portion. At least a portion of the first terminal portion is accommodated in a first electrode lead-out hole, and the second terminal portion protrudes from the outer peripheral surface of the first terminal portion. The second terminal portion is located on one side of the wall portion along its own thickness direction. A first conductive component is connected to the second terminal portion, and a first insulating gap is formed between the wall portion and the second terminal portion. The volume of the first conductive component is larger than the volume of the first insulating gap. When an external short circuit occurs in the battery cell, the first conductive component melts upon heating and can directly flow into and fill the first insulating gap under its own gravity. This improves the reliability and efficiency of the first conductive component in conducting the first electrode terminal and the wall portion, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of battery cell fire and explosion, and improves reliability.

[0015] In some embodiments, along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion; the battery cell includes a first insulating member, at least a portion of which is sandwiched between the wall portion and the second terminal portion along the thickness direction of the wall portion. The first insulating member has a first through hole, which penetrates the first insulating member along the thickness direction of the wall portion, forming a first insulating gap. When the battery cell is used upside down, the wall portion forms the bottom wall of the casing, and the second terminal portion is located above the wall portion. The first conductive member is located above at least a portion of the first insulating gap. When an external short circuit occurs in the battery cell, the first conductive member melts upon heating and can flow directly into the first insulating gap under its own gravity. This improves the efficiency of the first conductive member in conducting the first electrode terminal and the wall portion, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of battery cell fire and explosion, and improves reliability.

[0016] In some embodiments, along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion; the battery cell includes a first insulating member and a sealing member. Along the thickness direction of the wall portion, at least a portion of the first insulating member is sandwiched between the wall portion and the second terminal portion, and a portion of the sealing member is sandwiched between the wall portion and the second terminal portion. The sealing member is spaced apart on the side of the first insulating member near the first terminal portion. The sealing member, the first insulating member, the second terminal portion, and the wall portion together form a first insulating gap. Neither the sealing member nor the first insulating member requires openings, and there is no need to change or damage the original structure of the sealing member and the first insulating member. This simplifies the process, reduces the adverse effects on the structural strength of the sealing member and the first insulating member, and reduces the impact on the sealing and insulation performance of the battery cell.

[0017] In some embodiments, the melting point of the first conductive component is lower than that of the first insulating component and the sealing component. When an external short circuit occurs in a battery cell, the first conductive component can melt preferentially before the sealing component, thereby promptly connecting the first electrode terminal and the wall portion, and then melting the overcurrent component to disconnect the current circuit of the battery cell. This helps to reduce the risk of sealing failure of the battery cell before the current circuit is disconnected, and improves the reliability of the battery cell.

[0018] In some embodiments, along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing away from the main body portion; the battery cell includes a second insulating member, at least a portion of which is sandwiched between the wall portion and the second terminal portion along the thickness direction of the wall portion. The second insulating member has a second through hole, which penetrates the second insulating member along the thickness direction of the wall portion, forming a first insulating gap. When the battery cell is placed upright for use, the wall portion forms the top wall of the casing, and the second terminal portion is located above the wall portion. The first conductive member is located above at least a portion of the first insulating gap. When an external short circuit occurs in the battery cell, the first conductive member melts upon heating and can flow directly into the first insulating gap under its own gravity. This improves the efficiency of the first conductive member in conducting the first electrode terminal and the wall portion, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of battery cell fire and explosion, and improves reliability.

[0019] In some embodiments, the melting point of the first conductive component is lower than that of the second insulating component. The first conductive component can melt preferentially before the second insulating component, thereby promptly connecting the first electrode terminal and the wall portion, and then melting the overcurrent component to disconnect the current circuit of the battery cell. This helps to reduce the risk of insulation failure of the battery cell before the current circuit is disconnected, and improves the reliability of the battery cell.

[0020] In some embodiments, at least a portion of the first conductive member is embedded in the second terminal portion. This enhances the connection strength between the first conductive member and the second terminal portion while reducing the space occupied by the first conductive member, thus improving the structural compactness and energy density of the battery cell. Furthermore, it reduces the space occupied by the first conductive member in the first insulation gap, lowering the risk of the battery cell being short-circuited by the first conductive member under normal operating conditions.

[0021] In some embodiments, the first conductive member does not extend beyond the surface of the second terminal portion facing the wall portion in the direction from the second terminal portion to the wall portion. Therefore, the first conductive member does not occupy additional space along the thickness direction of the wall portion, and the second conductive member does not affect the compression fit between the second terminal portion and other components (e.g., seals, first insulators, or second insulators), which is beneficial for improving the sealing performance of the battery cell.

[0022] In some embodiments, the volume of the first conductive component is V2, and the volume of the first insulating gap is V0′, where 1 < V2 / V0′ ≤ 2, and optionally, 1.3 ≤ V2 / V0′ ≤ 1.8. When V2 / V0′ is greater than 1, the volume of the first conductive component is larger than the volume of the first insulating gap. After the first conductive component melts, it can fill the first insulating gap, thus enabling the second terminal portion and the wall portion to conduct electricity, thereby generating a large instantaneous current to melt the overcurrent device. When V2 / V0′ is less than or equal to 2, it is beneficial to reduce the amount of the first conductive component used, lowering costs, and also reducing the adverse effects of the first conductive component's placement on the structural strength of the second terminal portion.

[0023] In some embodiments, the projections of the first conductive component and the first insulating gap partially overlap along the thickness direction of the wall portion. The volume of the first conductive component is slightly larger than the volume of the first insulating gap, allowing the wall portion and the second terminal portion to conduct electricity after the first conductive component fills the first insulating gap. This helps reduce the required volume of the first conductive component and lowers costs. Furthermore, the portion of the first conductive component that is offset from the first insulating gap can be supported by other structures (e.g., a first insulating member or a second insulating member), reducing the risk of the first conductive component detaching from the second terminal portion and short-circuiting the wall portion and the second terminal portion. This improves the installation stability of the first conductive component and the reliability of the battery cell.

[0024] In some embodiments, the area of ​​the overlapping portion of the projection of the first conductive component and the projection of the insulating gap is S1, and the projected area of ​​the insulating gap is S2, where 0 < S1 / S2 ≤ 0.9, and optionally, 0.1 < S1 / S2 ≤ 0.5. When S1 / S2 is greater than zero, the first conductive component, after being heated and melted, can flow into the first insulating gap. When S1 / S2 is less than or equal to 0.9, the area of ​​the portion of the first insulating gap opposite to the first conductive component is not too large, and the first insulating gap can have a larger area opposite to the second terminal portion. After the molten first conductive component fills the first insulating gap, a larger current-carrying area can be obtained between the second terminal portion and the wall portion, which is beneficial for further reducing short-circuit resistance, increasing short-circuit current, and improving the fusing efficiency of the current-carrying component.

[0025] In some embodiments, the melting point of the first conductive component is less than or equal to 400°C. The relatively low melting point of the first conductive component facilitates preferential melting in the event of an external short circuit in the battery cell, thereby short-circuiting the wall and the first electrode terminal, and a wide range of options are available for the first conductive component.

[0026] In some embodiments, the first conductive component includes any one of lead-bismuth alloy, metallic tin, metallic bismuth, and metallic lead.

[0027] In some embodiments, the electrode assembly further includes a second tab extending from the main body, the second tab having opposite polarity to the first tab; the battery cell includes a second electrode terminal electrically connected to the wall and the second tab. When an external short circuit occurs in the battery cell, the first conductive component melts upon heating, filling the first insulating gap, thereby connecting the wall and the first electrode terminal. This allows the first and second electrode terminals to be connected via the wall. The relatively low resistance of the wall reduces the short-circuit resistance, generating a large instantaneous current inside the battery cell, which melts the first adapter or tab, thus reducing the risk of battery cell fire and explosion and improving the reliability of the battery cell.

[0028] In some embodiments, the electrode assembly includes a second tab extending from the main body, the second tab having opposite polarities to the first tab; the battery cell includes a second electrode terminal and a second conductive component, the second electrode terminal being connected to the second tab and insulated from the wall, a second insulating gap being formed between the second electrode terminal and the wall, the second conductive component being connected to the second electrode terminal and insulated from the wall, at least a portion of the second conductive component being exposed in the second insulating gap, and the melting point of the second conductive component being lower than that of the second electrode terminal. When an external short circuit occurs in the battery cell, the second electrode terminal heats up, rapidly melting the second conductive component. The melted second conductive component fills at least a portion of the space in the second insulating gap, thereby connecting the second electrode terminal and the wall, thus directly connecting the first electrode terminal and the second electrode terminal through the wall. This reduces the short-circuit resistance, increases the short-circuit current, and melts some overcurrent components (e.g., adapters, tabs, etc.) in the current loop, which helps reduce the risk of battery cell fire and explosion and improves the reliability of the battery cell.

[0029] According to a second aspect of this application, this application provides a battery device comprising a plurality of battery cells provided according to any embodiment of the first aspect of this application.

[0030] According to a third aspect of this application, this application provides an electrical device that includes a battery device provided according to any embodiment of the second aspect of this application, the battery device being used to provide electrical energy. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0033] Figure 2 This is an exploded structural diagram of a battery provided in some embodiments of this application.

[0034] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0035] Figure 4 This is a cross-sectional schematic diagram of a battery cell provided in some embodiments of this application.

[0036] Figure 5 yes Figure 4 A magnified structural diagram of region A in the middle.

[0037] Figure 6 This is a cross-sectional schematic diagram of a battery cell provided in some other embodiments of this application.

[0038] Figure 7 yes Figure 6 A magnified structural diagram of region B in the middle.

[0039] Figure 8 This is a partial structural cross-sectional schematic diagram of a battery cell provided in some embodiments of this application.

[0040] Figure 9 This is a partial structural cross-sectional schematic diagram of a battery cell provided in some embodiments of this application.

[0041] Figure 10 This is a cross-sectional view of another part of the structure of a battery cell provided in some embodiments of this application.

[0042] In the attached image:

[0043] Vehicle 1, battery pack 2, controller 3, motor 4, housing 5;

[0044] Electrode assembly 10, main body 11, first electrode tab 12, second electrode tab 13, outer shell 20, housing 21, opening 21a, end cap 22, wall 23, first electrode lead-out hole 231, hole wall 231a, first electrode terminal 30, first terminal part 31, outer peripheral surface 31a, second terminal part 32, third terminal part 33, first conductive component 41, inner peripheral surface 41a, outer peripheral surface 41b, second conductive component 42, sealing component 51, first insulating component 52, first through hole 521, second insulating component 53, second through hole 531, first housing part 5a, second housing part 5b, accommodating space 5c, battery cell 6, first adapter 61, second electrode terminal 70, first insulation gap P1, first insulation gap P2, second insulation gap P2, thickness direction X. Detailed Implementation

[0045] 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.

[0046] 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.

[0047] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this application, "multiple" means two or more (including two).

[0052] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0053] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0054] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0055] A typical battery cell includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are located within the housing. The housing encapsulates the electrode assembly and electrolyte components. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to external circuitry within the battery cell to enable charging or discharging of the battery cell.

[0056] 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.

[0057] 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.

[0058] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0059] In some implementations, the separator is positioned between the positive and negative electrodes.

[0060] 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.

[0061] 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.

[0062] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0063] In some embodiments, the electrode assembly has a stacked structure.

[0064] 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.

[0065] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0066] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0067] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0068] 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.

[0069] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0070] When a battery cell experiences an external short circuit during assembly or abuse testing, the electrode terminals will be subjected to a large external short current. This will generate a large amount of heat at the electrode terminals, causing them to heat up rapidly. If the external short circuit continues, it may cause the seals and insulation components of the battery cell to melt, leading to failure of the seals and insulation. The melting of the electrode terminals, coupled with the electrolyte vapor inside the battery cell, can easily cause smoke and fire, posing a significant safety hazard.

[0071] In view of this, this application provides a technical solution that involves setting a first insulating gap between the first electrode terminal and the wall of the casing, and connecting a first conductive component with a relatively low melting point to the first electrode terminal, with at least a portion of the first conductive component exposed in the first insulating gap. When an external short circuit occurs in the battery cell, the first electrode terminal heats up, rapidly melting the first conductive component. The melted first conductive component fills the first insulating gap, thereby connecting the first electrode terminal and the wall. The wall directly connects the positive and negative terminals of the battery cell, reducing short-circuit resistance, increasing short-circuit current, and melting some overcurrent components (such as adapters, tabs, etc.) in the current loop, which helps reduce the risk of battery cell fire and explosion and improves the reliability of the battery cell.

[0072] The technical solutions provided in this application are applicable to battery cells, battery devices, and electrical equipment using battery devices.

[0073] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0074] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0075] Figure 1 This is a structural schematic diagram of a vehicle provided in some embodiments of this application. (Refer to...) Figure 1 Vehicle 1 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 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. 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, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0076] 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.

[0077] Figure 2This is an exploded structural diagram of a battery device provided in some embodiments of this application. (Refer to...) Figure 2 The battery device 2 includes a housing 5 and battery cells 6, with the battery cells 6 housed within the housing 5. The housing 5 provides a accommodating space 5c for the battery cells 6, and the housing 5 can employ 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, together defining the accommodating space 5c for accommodating the battery cells 6. The second housing portion 5b may be a hollow structure with one open end, while the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b together define the accommodating space; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one open side, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0078] 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.

[0079] 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.

[0080] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

[0081] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0082] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. (Refer to...) Figure 3 The battery cell 6 includes a housing 20 and an electrode assembly 10, with the electrode assembly 10 housed within the housing 20.

[0083] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0084] In some embodiments, the housing 20 is a hollow structure, with an internal space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cuboid structure, a cuboid housing can be selected.

[0085] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0086] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening 21a and the end cap 22 for closing the opening 21a.

[0087] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0088] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 6.

[0089] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21.

[0090] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0091] The housing 21 may be open at one end or open at both ends. For example, the housing 21 may be open on one side, with one end cap 22 covering the opening of the housing 21. Alternatively, the housing 21 may be open on both sides, with two end caps 22 covering the two openings of the housing 21 respectively.

[0092] Figure 4 This is a cross-sectional schematic diagram of a battery cell provided in some embodiments of this application. Figure 5 yes Figure 4 A magnified structural diagram of region A in the middle. Figure 6 These are cross-sectional schematic diagrams of battery cells provided in other embodiments of this application. Figure 7 yes Figure 6 A magnified structural diagram of region B in the middle. Figure 8 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application. Figure 9 This is a partial cross-sectional view of a battery cell provided in some embodiments of this application. Figure 10 This is a cross-sectional view of another part of the structure of a battery cell provided in some embodiments of this application.

[0093] Reference Figures 3 to 10 In some embodiments, the battery cell 6 includes an electrode assembly 10, a housing 20, a first electrode terminal 30, and a first conductive component 41. The housing 20 includes a wall portion 23, which has a first electrode lead-out hole 231. The electrode assembly 10 is housed within the housing 20 and includes a main body portion 11 and a first tab 12 extending from the main body portion 11. The first electrode terminal 30 is disposed in the first electrode lead-out hole 231 and is insulated from the wall portion 23, forming a first insulating gap P1 between the first electrode terminal 30 and the wall portion 23. The first conductive component 41 is connected to the first electrode terminal 30 and is insulated from the wall portion 23, with at least a portion of the first conductive component 41 exposed in the first insulating gap P1. The melting point of the first conductive component 41 is lower than the melting point of the first electrode terminal 30.

[0094] Optionally, the first electrode tab 12 may be extended from the side of the main body 11 facing the wall portion 23 to facilitate connection with the first electrode terminal 30.

[0095] The wall portion 23 can be the end cap 22 or one of the walls of the housing 21.

[0096] The first electrode lead-out hole 231 extends through the wall portion 23 along the thickness direction X. At least a portion of the first electrode terminal 30 can be exposed on the outside of the wall portion 23 facing away from the main body portion 11 through the first electrode lead-out hole 231, so as to facilitate connection to external circuits.

[0097] The first electrode terminal 30 is insulated from the wall portion 23. Optionally, the first electrode terminal 30 and the wall portion 23 can be insulated by a gap or by an insulating component.

[0098] The first conductive component 41 may be located at least partially within the first insulating gap P1, or it may be located outside the first insulating gap P1.

[0099] There may be one or more first conductive components 41. The first conductive component 41 may be dot-shaped, strip-shaped, arc-shaped, or ring-shaped, etc.

[0100] The first insulating gap P1 can be one or more. The first insulating gap P1 can be hole-shaped, strip-shaped, arc-shaped, or ring-shaped, etc.

[0101] A first insulating gap P1 is formed between the first electrode terminal 30 and the wall portion 23, and the first electrode terminal 30 and the wall portion 23 form a portion that encloses the first insulating gap P1. A portion of the first electrode terminal 30 and a portion of the wall portion 23 are both directly exposed in the first insulating gap P1.

[0102] At least a portion of the first conductive component 41 is exposed in the first insulating gap P1. Before the first conductive component 41 melts, at least a portion of the first conductive component 41 can be insulated from the wall portion 23 through the first insulating gap P1. A portion of the first conductive component 41 can also be insulated from the wall portion 23 through an insulating component, thereby reducing the risk that the first conductive component 41 will conduct electricity between the first electrode terminal 30 and the wall portion 23 when the battery cell 6 is in normal use. After the first conductive component 41 is heated and melted, the molten first conductive component 41 can flow to the first insulating gap P1, thereby filling at least a portion of the space in the first insulating gap P1.

[0103] A portion of the wall portion 23 is exposed in the first insulating gap P1. After the first conductive component 41, which is in a molten state, flows into the first insulating gap P1, it can come into contact with the wall portion 23. The wall portion 23 can be electrically connected to the first electrode terminal 30 through the first conductive component 41.

[0104] To ensure the sealing performance of the battery cell 6, the first insulating gap P1 can be a closed gap formed between the first electrode terminal 30 and the wall portion 23. The first electrode terminal 30 and the wall portion 23 can be combined with other structures of the battery cell 6 to form a closed first insulating gap P1. When the first conductive component 41 is heated and melts, flowing into the first insulating gap P1, the possibility of the first conductive component 41 flowing out of the first insulating gap P1 can be reduced, which is beneficial to improving the efficiency of the first conductive component 41 in conducting the first electrode terminal 30 and the wall portion 23.

[0105] The first conductive component 41 can be connected to the first electrode terminal 30 by welding, bonding, abutting or other suitable means, as long as the first conductive component 41 and the first electrode terminal 30 can be in direct contact. The heat generated by the first electrode terminal 30 can be transferred to the first conductive component 41, which is beneficial for the first conductive component 41 to melt when the first electrode terminal 30 is heated.

[0106] When an external short circuit occurs in battery cell 6, the first electrode terminal 30 heats up, rapidly melting the first conductive component 41. The melted first conductive component 41 fills at least part of the space in the first insulating gap P1, thereby connecting the first electrode terminal 30 and the wall portion 23. The wall portion 23 can directly connect the positive and negative terminals of battery cell 6, reducing short-circuit resistance, increasing short-circuit current, and melting some overcurrent components in the current loop (such as adapter plates, tabs, etc.), which helps reduce the risk of battery cell 6 catching fire and exploding, and improves the reliability of battery cell 6.

[0107] In some embodiments, the first conductive component 41 includes any one of lead-bismuth alloy, metallic tin, metallic bismuth, and metallic lead.

[0108] In some embodiments, at least a portion of the first insulating gap P1 is located between the first conductive member 41 and the wall portion 23 along the arrangement direction of the first conductive member 41 and the wall portion 23.

[0109] The first conductive component 41 and the wall portion 23 can be arranged along the thickness direction X of the wall portion 23, or they can be arranged in a direction perpendicular to the thickness direction X.

[0110] In some examples, the first conductive component 41 may be located outside the first insulating gap P1, and the first insulating gap P1 may be entirely located between the first conductive component 41 and the wall portion 23, or only a portion of the first insulating gap P1 may be located between the first conductive component 41 and the wall portion 23.

[0111] In other examples, the first conductive component 41 may be located inside the first insulating gap P1, occupying a portion of the space of the first insulating gap P1, with only a portion of the first insulating gap P1 located between the first conductive component 41 and the wall portion 23.

[0112] At least a portion of the first insulating gap P1 is located between the first conductive component 41 and the wall portion 23. The first conductive component 41 and the wall portion 23 can be arranged opposite each other through at least a portion of the first insulating gap P1, which can shorten the distance that the melted first conductive component 41 flows to the wall portion 23, improve the efficiency of the first conductive component 41 in conducting the wall portion 23 and the first electrode terminal 30, and help to melt and break some of the overcurrent components in the current circuit as soon as possible, so as to further reduce the risk of fire and explosion of the battery cell 6.

[0113] In some embodiments, the volume of the first conductive component 41 is larger than the volume of the first insulating gap P1.

[0114] After the first conductive component 41 melts, it can fill the first insulating gap P1, so as to more reliably connect the wall portion 23 and the first electrode terminal 30. In addition, it can increase the current-passing area between the wall portion 23 and the first electrode terminal 30, so as to reduce the short-circuit resistance, increase the short-circuit current, and facilitate the faster melting of some of the current-passing components in the current loop.

[0115] In some embodiments, the first insulation gap P1 is an annular gap extending circumferentially along the first electrode terminal 30.

[0116] The first insulating gap P1 extends circumferentially along the first electrode terminal 30. After the first conductive component 41 melts and flows into the first insulating gap P1, the first conductive component 41 can extend circumferentially along the first electrode terminal 30, which is beneficial to increase the overcurrent area between the first electrode terminal 30 and the wall 23, thereby reducing the short-circuit resistance and increasing the short-circuit current. This is beneficial to melt and break the overcurrent components in the current circuit more quickly, thereby reducing the risk of fire and explosion of the battery cell 6.

[0117] In some embodiments, the first conductive component 41 is an annular component extending circumferentially along the first electrode terminal 30.

[0118] The first conductive component 41 and the first insulating gap P1 are matched in shape. When the first conductive component 41 is heated, it can flow into the annular first insulating gap P1 more quickly and evenly. This helps to shorten the time when the first conductive component 41 conducts the first electrode terminal 30 and the wall 23, shorten the duration of the external short circuit of the battery cell 6, and reduce the risk of the battery cell 6 catching fire and exploding.

[0119] In some embodiments, refer to Figure 4 and Figure 5 At least a portion of the first electrode terminal 30 is accommodated in the first electrode lead-out hole 231, and the first insulating gap P1 is located between the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231. The first conductive component 41 is accommodated in the first insulating gap P1.

[0120] At least a portion of the first insulating gap P1 may be disposed around the first electrode terminal 30 to achieve insulation between the first electrode terminal 30 and the wall portion 23.

[0121] In some examples, the first insulating gap P1 may be integrally formed between the outer peripheral surface of the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231.

[0122] In other examples, only a portion of the first insulating gap P1 is formed between the outer peripheral surface of the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231. A portion of the first insulating gap P1 may also be formed inside the first electrode terminal 30. That is, a portion of the first insulating gap P1 may be recessed into the outer peripheral surface of the first electrode terminal 30, and at least a portion of the first conductive member 41 may be embedded inside the first electrode terminal 30.

[0123] Along the thickness direction of the wall portion 23, the first insulating gap P1 does not extend beyond the surface of the wall portion 23 facing the main body portion 11, nor does the first insulating gap P1 extend beyond the surface of the wall portion 23 facing away from the main body portion 11.

[0124] When an external short circuit occurs in the battery cell 6, the temperature of the first electrode terminal 30 rises, and the first conductive component 41 melts due to heat. The molten first conductive component 41 flows along the direction of gravity to the bottom of the first insulating gap P1 in the direction of gravity, and continues to flow laterally to the wall 23, thereby connecting the wall 23 and the first electrode terminal 30.

[0125] The first conductive component 41 is connected to the portion of the first electrode terminal 30 that is housed in the first electrode lead-out hole 231. This portion of the first electrode terminal 30, housed in the first electrode lead-out hole 231, experiences greater current flow, generates more heat, and has a relatively higher temperature. When an external short circuit occurs in the battery cell 6, the first conductive component 41 is more easily melted, facilitating faster conduction between the first electrode terminal 30 and the wall portion 23, thus reducing the risk of fire and explosion in the battery cell 6. Furthermore, regardless of whether the battery cell 6 is placed upright or upside down, the molten first conductive component 41 can conduct electricity between the wall portion 23 and the first electrode terminal 30, making it widely applicable.

[0126] In some embodiments, the first conductive component 41 is disposed around the first electrode terminal 30, and the inner peripheral surface 41a of the first conductive component 41 is attached to the outer peripheral surface of the first electrode terminal 30.

[0127] In these embodiments, the first insulating gap P1 is located between the outer peripheral surface of the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231, and the outer peripheral surface of the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231 can be spaced apart by the first insulating gap P1.

[0128] The wall portion 23 may be disposed around the first conductive member 41. The outer peripheral surface 41b of the first conductive member 41 and the hole wall 231a of the first electrode lead-out hole 231 are spaced apart. The gap between the outer peripheral surface 41b of the first conductive member 41 and the hole wall 231a of the first electrode lead-out hole 231 forms part of the first insulating gap P1.

[0129] The first conductive component 41 can be sleeved on the outside of the first electrode terminal 30, which simplifies the assembly of the first conductive component 41 and the first electrode terminal 30. Furthermore, the first conductive component 41 does not occupy the current-carrying space of the first electrode terminal 30, which helps to increase the current-carrying area of ​​the first electrode terminal 30 and improve its current-carrying capacity. At the same time, it also helps to shorten the distance between the first conductive component 41 and the wall portion 23, reducing the required volume of the first conductive component 41 and saving costs.

[0130] In some embodiments, along the thickness direction X of the wall portion 23, both ends of the first conductive member 41 are flush with both ends of the first insulating gap P1. The volume of the first conductive member 41 is V1, and the volume of the first insulating gap P1 is V0, where 0.3 ≤ V1 / V0 ≤ 0.8. Optionally, 0.5 ≤ V1 / V0 ≤ 0.7.

[0131] The volume of the gap between the outer peripheral surface 41b of the first conductive component 41 and the hole wall 231a of the first electrode lead-out hole 231, and the volume V1 of the first conductive component 41, is the volume V0 of the first insulating gap P1.

[0132] Optionally, V1 / V0 can be any value between 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or any two of them.

[0133] In this embodiment, V1 / V0 is set to be greater than or equal to 0.3. The volume of the first conductive component 41 relative to the first insulating gap P1 is not too small. After the first conductive component 41 melts, it can at least fill the bottom space of the first insulating gap P1 along the gravity direction (when the thickness direction X is vertical, the gravity direction is parallel to the thickness direction X), thereby effectively connecting the wall 23 and the first electrode terminal 30. Furthermore, the current-carrying area of ​​the first conductive component 41 is not too small, which is beneficial to increasing the short-circuit current and improving the efficiency of the current-carrying component melting.

[0134] In this embodiment, V1 / V0 is set to be less than or equal to 0.8. The volume of the first conductive component 41 relative to the first insulation gap P1 is not too large. Under the normal use of the battery cell 6, the space of the first insulation gap P1 not occupied by the first conductive component 41 is not too small. A relatively large gap can be formed between the first conductive component 41 and the wall portion 23, which helps to reduce the risk of the first conductive component 41 and the wall portion 23 becoming conductive due to assembly errors.

[0135] In this embodiment, V1 / V0 is set to 0.3-0.8, which helps to balance the reliability of the battery cell 6 under normal use and the overcurrent protection function under external short circuit conditions.

[0136] In some embodiments, the first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32. At least a portion of the first terminal portion 31 is received in a first electrode lead-out hole 231, and the second terminal portion 32 protrudes from the outer peripheral surface of the first terminal portion 31. Along the thickness direction of the wall portion 23, the second terminal portion 32 is located on the side of the wall portion 23 facing the main body portion 11. The battery cell 6 includes a seal 51, a portion of which is sandwiched between the wall portion 23 and the second terminal portion 32 along the thickness direction X of the wall portion 23. Along the direction from the main body portion 11 to the wall portion 23, the seal 51 covers the first insulating gap P1.

[0137] The first terminal portion 31 passes through the first electrode lead-out hole 231. The first terminal portion 31 may be entirely accommodated in the first electrode lead-out hole 231, or only a part of the first terminal portion 31 may be accommodated in the first electrode lead-out hole 231. A part of the first terminal portion 31 may extend out of the first electrode lead-out hole 231. For example, a part of the first terminal portion 31 may be located on the side of the wall portion 23 facing away from the main body portion 11.

[0138] Optionally, the first electrode terminal 30 further includes a third terminal portion 33, which protrudes from the outer peripheral surface of the first terminal portion 31 and is located on the side of the wall portion 23 facing away from the main body portion 11 along the thickness direction of the wall portion 23. The third terminal portion 33 may be integrally formed with the first terminal portion 31 or connected by welding, riveting or other suitable means.

[0139] The first terminal portion 31 can be a columnar structure. A first insulating gap P1 is formed between the first terminal portion 31 and the hole wall 231a of the first electrode lead-out hole 231.

[0140] Optionally, the first conductive component 41 may be disposed around the first terminal portion 31, and the inner peripheral surface 41a of the first conductive component 41 may be attached to the outer peripheral surface 31a of the first terminal portion 31.

[0141] The second terminal portion 32 may be disposed around the first terminal portion 31. Optionally, the first terminal portion 31 and the second terminal portion 32 may be integrally formed.

[0142] The sealing member 51 may be disposed around the first terminal portion 31. The inner peripheral surface of the sealing member 51 may be attached to the outer peripheral surface 31a of the first terminal portion 31 to form a seal between the sealing member 51 and the first terminal portion 31.

[0143] The seal 51 can form a seal between the wall portion 23 and the second terminal portion 32 to improve the sealing performance of the battery cell 6. The seal 51 can also cover the first insulating gap P1 in the direction from the main body portion 11 to the wall portion 23. The seal 51 forms a part of the enclosure of the first insulating gap P1, which can reduce the risk of the first conductive component 41 in the molten state flowing out of the first insulating gap P1. This helps to save the volume required for the first conductive component 41 and improve the efficiency of the first conductive component 41 in the molten state in conducting the first electrode terminal 30 and the wall portion 23.

[0144] In some embodiments, the melting point of the first conductive component 41 is lower than the melting point of the seal 51.

[0145] The seal 51 can be made of silicone, rubber, etc.

[0146] Both the first conductive component 41 and the seal 51 are located close to the first electrode terminal 30, and the temperature difference between the locations of the first conductive component 41 and the seal 51 is small. When an external short circuit occurs in the battery cell 6, the first conductive component 41 can melt preferentially before the seal 51, thereby promptly connecting the first electrode terminal 30 and the wall portion 23, and then melting the overcurrent component to disconnect the current circuit of the battery cell 6. This helps reduce the risk of sealing failure of the battery cell 6 before the current circuit is disconnected, thus improving the reliability of the battery cell 6.

[0147] Table 1

[0148]

[0149] Table 1 shows... Figure 4 and Figure 5 The table shows experimental data for the corresponding embodiments and different comparative examples. In Table 1, Comparative Example 1 shows the case where the battery cell does not have the first conductive component 41, and an external short-circuit test is performed. Comparative Example 2 uses lead as the material for the first conductive component 41. The melting point of the first conductive component 41 is higher than that of the sealing component 51, which easily leads to smoke at the electrode terminals. Comparative Example 3, Example 1, and Example 2 all use tin as the material for the first conductive component 41. The difference is that in Comparative Example 3, V1 / V0 is 0.1, the volume of the first conductive component 41 is too small, and the short-circuit resistance formed after the first conductive component 41 melts is too large, which also easily leads to smoke at the electrode terminals. In Example 1 and Example 2, V1 / V0 is relatively large, the volume of the first conductive component 41 is relatively large, and failure is less likely to occur. The V1 / V0 ratios in Comparative Example 4 and Example 3 are not significantly different. The difference is that Comparative Example 4 uses bismuth metal as the material of the first conductive component 41, which has a higher resistance and is prone to smoke at the electrode terminals. In contrast, Example 3 uses a lead-bismuth alloy as the material of the first conductive component 41, which is less prone to failure.

[0150] In some embodiments, refer to Figures 6 to 9 The first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32. At least a portion of the first terminal portion 31 is accommodated in a first electrode lead-out hole 231. The second terminal portion 32 protrudes from the outer peripheral surface 31a of the first terminal portion 31 and is located on one side of the wall portion 23 along its own thickness direction X. A first conductive member 41 is connected to the second terminal portion 32. A first insulating gap P1 is formed between the wall portion 23 and the second terminal portion 32. The volume of the first conductive member 41 is larger than the volume of the first insulating gap P1.

[0151] The second terminal portion 32 may be disposed around the first terminal portion 31. The second terminal portion 32 may be integrally formed with the first terminal portion 31, or it may be connected to the first terminal portion 31 by riveting, welding, bonding or other suitable means.

[0152] Along the thickness direction X of the wall portion 23, the second terminal portion 32 may be located on the side of the wall portion 23 facing the main body portion 11, or on the side of the wall portion 23 away from the main body portion 11.

[0153] The first conductive component 41 can be connected to the second terminal portion 32 by welding, riveting, abutting, or other suitable means. The first conductive component 41 is exposed on the side of the second terminal portion 32 facing the wall portion 23, so as to be at least partially exposed in the first insulating gap P1. The first conductive component 41 is connected to the second terminal portion 32, which is located on one side of the wall portion 23, and the first insulating gap P1 is formed between the wall portion 23 and the second terminal portion 32. When the battery cell 6 is placed upright or upside down, the first conductive component 41 can be located above the first insulating gap P1 in the direction of gravity parallel to the thickness direction X of the wall portion 23. When the battery cell 6 experiences an external short circuit, the first conductive component 41 melts when heated and can flow directly into the first insulating gap P1 under its own gravity, filling the first insulating gap P1. This helps to improve the reliability and efficiency of the first conductive component 41 in conducting the first electrode terminal 30 and the wall portion 23, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of fire and explosion of the battery cell 6, and improves reliability.

[0154] In some embodiments, refer to Figure 7 Along the thickness direction X of the wall portion 23, the second terminal portion 32 is located on the side of the wall portion 23 facing the main body portion 11. The battery cell 6 includes a first insulating member 52. Along the thickness direction of the wall portion 23, at least a portion of the first insulating member 52 is sandwiched between the wall portion 23 and the second terminal portion 32. The first insulating member 52 is provided with a first through hole 521. The first through hole 521 penetrates the first insulating member 52 along the thickness direction X of the wall portion 23, and the first through hole 521 forms a first insulating gap P1.

[0155] Optionally, the first electrode terminal 30 further includes a third terminal portion 33, which protrudes from the outer peripheral surface of the first terminal portion 31 and is located on the side of the wall portion 23 facing away from the main body portion 11 along the thickness direction of the wall portion 23. The third terminal portion 33 may be integrally formed with the first terminal portion 31 or connected by welding, riveting or other suitable means.

[0156] The first insulating member 52 may be connected to the wall portion 23 to insulate and isolate the wall portion 23 from the first electrode terminal 30. The first insulating member 52 may also be used to insulate and isolate the wall portion 23 from the housing 21.

[0157] Optionally, the first insulating element 52 can be a plastic part.

[0158] The second terminal portion 32, the first insulating member 52, and the wall portion 23 are pressed together to improve the sealing performance.

[0159] Along the thickness direction X of the wall portion 23, the projection of the first through hole 521 and the projection of the first conductive component 41 at least partially overlap.

[0160] The first conductive component 41 may be at least partially housed in the first through hole 521, or it may be located outside the first through hole 521.

[0161] The thickness direction X of the wall portion 23 can be parallel to the vertical direction. When the battery cell 6 is used upside down, the wall portion 23 forms the bottom wall of the outer casing 20, and the second terminal portion 32 is located above the wall portion 23. The first conductive component 41 is located above at least a portion of the first insulating gap P1. When the battery cell 6 experiences an external short circuit, the first conductive component 41 melts upon heating and can flow directly into the first insulating gap P1 under its own gravity. This improves the efficiency of the first conductive component 41 in conducting the first electrode terminal 30 and the wall portion 23, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of fire and explosion of the battery cell 6, and improves reliability.

[0162] Furthermore, the first through hole 521 is opened on the first insulating member 52 to form the first insulating gap P1, which will not affect the insulation effect of the battery cell 6 under normal use.

[0163] In some embodiments, refer to Figure 8 Along the thickness direction X of the wall portion 23, the second terminal portion 32 is located on the side of the wall portion 23 facing the main body portion 11. The battery cell 6 includes a first insulating member 52 and a sealing member 51. Along the thickness direction X of the wall portion 23, at least a portion of the first insulating member 52 is sandwiched between the wall portion 23 and the second terminal portion 32, and a portion of the sealing member 51 is sandwiched between the wall portion 23 and the second terminal portion 32. The sealing member 51 is spaced apart on the side of the first insulating member 52 near the first terminal portion 31. The sealing member 51, the first insulating member 52, the second terminal portion 32 and the wall portion 23 together form a first insulating gap P1.

[0164] Optionally, the first electrode terminal 30 further includes a third terminal portion 33, which protrudes from the outer peripheral surface of the first terminal portion 31 and is located on the side of the wall portion 23 facing away from the main body portion 11 along the thickness direction of the wall portion 23. The third terminal portion 33 may be integrally formed with the first terminal portion 31 or connected by welding, riveting or other suitable means.

[0165] The sealing member 51 is closer to the first terminal portion 31 than the first insulating member 52, and the first insulating member 52 may be disposed around the sealing member 51. The sealing member 51, the first insulating member 52, the second terminal portion 32 and the wall portion 23 may be enclosed to form an annular first insulating gap P1.

[0166] The first insulation gap P1 is formed by the sealing element 51, the first insulating element 52, the second terminal portion 32, and the wall portion 23. Neither the sealing element 51 nor the first insulating element 52 needs to be opened, and there is no need to change or damage the original structure of the sealing element 51 and the first insulating element 52. This is beneficial to simplify the process, reduce the adverse effects on the structural strength of the sealing element 51 and the first insulating element 52, and reduce the impact on the sealing and insulation performance of the battery cell 6.

[0167] In some embodiments, the melting point of the first conductive component 41 is lower than the melting points of the first insulating component 52 and the sealing component 51.

[0168] Both the first conductive component 41 and the seal 51 are close to the second terminal portion 32. The seal 51 is closer to the first terminal portion 31 than the first conductive component 41. The temperature at the location of the seal 51 may be higher than the temperature at the location of the first conductive component 41.

[0169] In this embodiment, the melting point of the first conductive component 41 is set to be lower than that of the sealing component 51. When an external short circuit occurs in the battery cell 6, the first conductive component 41 can melt preferentially before the sealing component 51, thereby promptly connecting the first electrode terminal 30 and the wall portion 23, and then melting the overcurrent component to disconnect the current circuit of the battery cell 6. This helps to reduce the risk of sealing failure of the battery cell 6 before the current circuit is disconnected, and improves the reliability of the battery cell 6.

[0170] Both the first conductive component 41 and the first insulating component 52 are located near the second terminal portion 32, and the temperature at the location of the first insulating component 52 is not significantly different from the temperature at the location of the first conductive component 41. In this embodiment, the melting point of the first conductive component 41 is set to be lower than that of the first insulating component 52. When an external short circuit occurs in the battery cell 6, the first conductive component 41 can melt preferentially before the first insulating component 52, thereby promptly connecting the first electrode terminal 30 and the wall portion 23, and then melting the overcurrent component to disconnect the current circuit of the battery cell 6. This helps to reduce the risk of insulation failure of the battery cell 6 before the current circuit is disconnected, and improves the reliability of the battery cell 6.

[0171] In some embodiments, refer to Figure 9 Along the thickness direction X of the wall portion 23, the second terminal portion 32 is located on the side of the wall portion 23 facing away from the main body portion 11. The battery cell 6 includes a second insulating member 53. Along the thickness direction X of the wall portion 23, at least a portion of the second insulating member 53 is sandwiched between the wall portion 23 and the second terminal portion 32. The second insulating member 53 is provided with a second through hole 531, which penetrates the second insulating member 53 along the thickness direction X of the wall portion 23, forming a first insulating gap P1.

[0172] Optionally, the first electrode terminal 30 further includes a third terminal portion 33, which protrudes from the outer peripheral surface of the first terminal portion 31 and is located on the side of the wall portion 23 facing the main body portion 11 along the thickness direction of the wall portion 23. The third terminal portion 33 may be integrally formed with the first terminal portion 31 or connected by welding, riveting or other suitable means.

[0173] The second insulating member 53 can be connected to the wall portion 23 to insulate and isolate the wall portion 23 from the first electrode terminal 30.

[0174] Optionally, the second insulating element 53 can be a plastic part.

[0175] Along the thickness direction X of the wall portion 23, the projection of the second through hole 531 and the projection of the first conductive component 41 at least partially overlap.

[0176] The thickness direction X of the wall portion 23 can be parallel to the vertical direction. When the battery cell 6 is placed upright for use, the wall portion 23 forms the top wall of the outer casing 20, and the second terminal portion 32 is located above the wall portion 23. The first conductive component 41 is located above at least a portion of the first insulating gap P1. When an external short circuit occurs in the battery cell 6, the first conductive component 41 melts upon heating and can flow directly into the first insulating gap P1 under its own gravity. This improves the efficiency of the first conductive component 41 in conducting the first electrode terminal 30 and the wall portion 23, shortens the melting time of some overcurrent components in the current circuit, reduces the risk of fire and explosion of the battery cell 6, and improves reliability.

[0177] In some embodiments, the melting point of the first conductive component 41 is lower than the melting point of the second insulating component 53.

[0178] Both the first conductive component 41 and the second insulating component 53 are located near the second terminal portion 32, and the temperature at the location of the second insulating component 53 is not significantly different from the temperature at the location of the first conductive component 41. In this embodiment, the melting point of the first conductive component 41 is set to be lower than that of the second insulating component 53. When an external short circuit occurs in the battery cell 6, the first conductive component 41 can melt preferentially before the second insulating component 53, thereby promptly connecting the first electrode terminal 30 and the wall portion 23, and then melting the overcurrent component to disconnect the current circuit of the battery cell 6. This helps to reduce the risk of insulation failure of the battery cell 6 before the current circuit is disconnected, and improves the reliability of the battery cell 6.

[0179] In some embodiments, the second terminal portion 32 is located on the side of the wall portion 23 facing away from the main body portion 11. Compared to the first terminal portion 31, the second terminal portion 32 has a smaller current flow and generates relatively less heat. Therefore, when the first conductive member 41 is connected to the second terminal portion 32, the first conductive member 41 may be a conductive metal with a low melting point. For example, the first conductive member 41 may be a lead-bismuth alloy.

[0180] In some embodiments, refer to Figures 7 to 9 At least a portion of the first conductive component 41 is embedded in the second terminal portion 32.

[0181] A recess may be provided on the side of the second terminal portion 32 facing the wall portion 23, the recess being recessed into the surface of the second terminal portion 32 facing the wall portion 23. In some examples, the first conductive member 41 may be completely accommodated in the recess, in which case the first conductive member 41 may be integrally embedded in the second terminal portion 32. In other examples, a portion of the first conductive member 41 is accommodated in the recess, and another portion of the first conductive member 41 protrudes from the recess toward the wall portion 23, in which case the first conductive member 41 is partially embedded in the second terminal portion 32.

[0182] The first conductive component 41 is at least partially embedded in the second terminal portion 32, which not only enhances the connection strength between the first conductive component 41 and the second terminal portion 32, but also reduces the space occupied by the first conductive component 41, thereby improving the structural compactness and energy density of the battery cell 6. Furthermore, it also reduces the space occupied by the first insulating gap P1 by the first conductive component 41, reducing the risk of the battery cell 6 being short-circuited by the first conductive component 41 under normal use.

[0183] In some embodiments, refer to Figures 7 to 9 Along the direction from the second terminal portion 32 to the wall portion 23, the first conductive component 41 does not extend beyond the surface of the second terminal portion 32 facing the wall portion 23.

[0184] The first conductive component 41 can be flush with the surface of the second terminal portion 32 facing the wall portion 23, or it can be further away from the wall portion 23 than the surface of the second terminal portion 32 facing the wall portion 23. Therefore, along the thickness direction X of the wall portion 23, the first conductive component 41 does not occupy additional space, and the first conductive component 41 does not affect the pressing fit between the second terminal portion 32 and other components (such as the seal 51, the first insulating component 52, or the second insulating component 53), which is beneficial to improving the sealing performance of the battery cell 6.

[0185] In some embodiments, refer to Figures 7 to 9 The volume of the first conductive component 41 is V2, and the volume of the first insulating gap P1 is V0′, where 1 < V2 / V0′ ≤ 2. Optionally, 1.3 ≤ V2 / V0′ ≤ 1.8.

[0186] When the first through hole 521 forms the first insulating gap P1, the volume V0′ of the first insulating gap P1 is the volume of the first through hole 521. When the second through hole 531 forms the first insulating gap P1, the volume V0′ of the first insulating gap P1 is the volume of the second through hole 531. When the sealing member 51, the first insulating member 52, the second terminal portion 32, and the wall portion 23 together enclose and form the first insulating gap P1, the volume V0′ of the first insulating gap P1 is the volume of the annular gap defined between the sealing member 51, the first insulating member 52, the second terminal portion 32, and the wall portion 23.

[0187] Optionally, V2 / V0′ can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, or any value between any two of them.

[0188] In this embodiment, V2 / V0′ is set to be greater than 1, and the volume of the first conductive component 41 is greater than the volume of the first insulating gap P1. After the first conductive component 41 melts, it can fill the first insulating gap P1, so that the second terminal portion 32 and the wall portion 23 can be connected, thereby generating a large instantaneous current to melt the overcurrent component.

[0189] In this embodiment, V2 / V0′ is set to be less than or equal to 2, which helps to reduce the amount of the first conductive component 41 used, reduce costs, and also reduce the adverse effect of the setting of the first conductive component 41 on the structural strength of the second terminal portion 32.

[0190] In some embodiments, refer to Figures 7 to 9 Along the thickness direction X of the wall portion 23, the projection of the first conductive component 41 and the projection of the first insulating gap P1 partially overlap.

[0191] Along the thickness direction X of the wall portion 23, a portion of the first conductive component 41 is exposed in the first insulating gap P1. That is, a portion of the first conductive component 41 is disposed opposite to the first insulating gap P1. After the first conductive component 41 is heated and melted, it can flow smoothly into the first insulating gap P1, thereby facilitating the conduction between the wall portion 23 and the first electrode terminal 30.

[0192] If the projection of the first conductive component 41 is within the projection of the first insulating gap P1, after the first conductive component 41 melts and fills the first insulating gap P1, the remaining portion of the first conductive component 41 still needs to be connected to the second terminal portion 32, and the required volume of the first conductive component 41 is relatively large.

[0193] In this embodiment, along the thickness direction X of the wall portion 23, another part of the first conductive component 41 is offset from the first insulating gap P1. The volume of the first conductive component 41 is slightly larger than the volume of the first insulating gap P1. After the first conductive component 41 fills the first insulating gap P1, the wall portion 23 and the second terminal portion 32 are connected. This helps to reduce the volume required for the first conductive component 41 and reduce costs.

[0194] Furthermore, the portion of the first conductive component 41 that is offset from the first insulation gap P1 can be supported by other structures (such as the first insulating component 52 or the second insulating component 53), reducing the risk that the first conductive component 41 will detach from the second terminal portion 32 and short-circuit the wall portion 23 and the second terminal portion 32, which is beneficial to improving the installation stability of the first conductive component 41 and the reliability of the battery cell 6.

[0195] In some embodiments, the area of ​​the overlapping portion of the projection of the first conductive component 41 and the projection of the first insulating gap P1 is S1, and the projected area of ​​the first insulating gap P1 is S2, where 0 < S1 / S2 ≤ 0.9, and optionally, 0.1 < S1 / S2 ≤ 0.5.

[0196] Optionally, S1 / S2 can be any value between 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or any two of these values.

[0197] In this embodiment, S1 / S2 is set to be greater than zero, and the first conductive component 41 can flow into the first insulating gap P1 after being heated and melted.

[0198] In this embodiment, S1 / S2 is set to less than or equal to 0.9. The area of ​​the portion of the first insulating gap P1 opposite to the first conductive component 41 is not too large. The first insulating gap P1 can have a large area opposite to the second terminal portion 32. After the molten first conductive component 41 fills the first insulating gap P1, a larger current-carrying area can be obtained between the second terminal portion 32 and the wall portion 23, which is beneficial to further reduce the short-circuit resistance, increase the short-circuit current, and improve the melting efficiency of the current-carrying component.

[0199] Table 2

[0200]

[0201] Table 2 is... Figures 6 to 9The table shows test data for the corresponding embodiments and different comparative examples. In Table 2, Comparative Example 6 shows the case where the battery cell does not have the first conductive component 41, and an external short-circuit test is performed. Comparative Examples 7 and 8 use lead and tin as the materials for the first conductive component 41, respectively. The melting point of the first conductive component 41 is higher than that of the second insulating component 53, which easily leads to smoke from the electrode terminals. Comparative Examples 9 to 11, as well as Examples 4 and 5, all use a lead-bismuth alloy as the material for the first conductive component 41. The difference is that V2 / V0′ in Comparative Example 9 is 0.9, and the volume of the first conductive component 41 is smaller than the volume of the first insulating gap P1. After the first conductive component 41 melts, it cannot conduct electricity between the first electrode terminal 30 and the wall 23, which easily leads to smoke from the electrode terminals. In Comparative Example 10, S1 / S2 is 0, the first conductive component 41 and the first insulating gap P1 do not overlap, and after the first conductive component 41 melts, it cannot effectively flow into the first insulating gap P1. Similarly, it cannot connect the first electrode terminal 30 and the wall portion 23, making it prone to electrode terminal melting and fire. In Examples 4 and 5, V2 / V0′ is greater than 1 and S1 / S2 is greater than 0. After the first conductive component 41 melts, it can normally flow into the first insulating gap P1 and connect the first electrode terminal 30 and the wall portion 23, making it less prone to failure. In Comparative Example 11, V2 / V0′ is slightly greater than 1 and S1 / S2 is equal to 1. The projections of the first conductive component 41 and the first insulating gap P1 completely overlap. After the first conductive component 41 melts and fills the first insulating gap P1, only a very small portion remains connected to the first electrode terminal 30. The short-circuit resistance is large, making it difficult to melt the current-carrying component, and making it prone to electrode terminal melting and fire.

[0202] In some embodiments, the melting point of the first conductive component 41 is less than or equal to 400°C.

[0203] Optionally, the melting point of the first conductive component 41 may be greater than 100°C.

[0204] The first conductive component 41 has a relatively low melting point, which makes it easier to melt preferentially in the event of an external short circuit in the battery cell 6, thereby short-circuiting the wall portion 23 and the first electrode terminal 30. Furthermore, the range of options for the first conductive component 41 is relatively wide.

[0205] In some embodiments, the battery cell 6 further includes a first adapter 61, which is connected to the first tab 12 and the first electrode terminal 30.

[0206] The first adapter 61 can be a sheet-like structure with uniform thickness. The first adapter 61 has a large current-carrying area, which is beneficial to improving the current-carrying capacity of the battery cell 6.

[0207] The melting point of the first conductive component 41 can be lower than that of the first adapter 61. In the event of an external short circuit in the battery cell 6, the first conductive component 41 can preferentially melt upon heating, thereby short-circuiting the wall portion 23 and the first electrode terminal 30. The battery cell 6 will instantly generate a large short-circuit current, which can melt the first tab 12 or the first adapter 61, breaking the current circuit. This embodiment does not require thinning or narrowing the first adapter 61 or other current-carrying components, and will not affect the performance of the battery cell 6 under normal conditions.

[0208] In some embodiments, the electrode assembly 10 further includes a second tab 13 extending from the main body 11, the second tab 13 having opposite polarity to the first tab 12. The battery cell 6 includes a second electrode terminal 70 electrically connected to the wall portion 23 and the second tab 13.

[0209] One of the first electrode tab 12 and the second electrode tab 13 is a positive electrode tab, and the other is a negative electrode tab. One of the first electrode terminal 30 and the second electrode terminal 70 is a positive terminal, and the other is a negative terminal.

[0210] Optionally, the first electrode 12 can be a negative electrode, and the second electrode 13 can be a positive electrode. Correspondingly, the first electrode terminal 30 is the positive terminal, and the second electrode terminal 70 is the negative terminal.

[0211] The second electrode terminal 70 can be directly electrically connected to the wall portion 23, or it can be indirectly connected to the wall portion 23 through a conductive component.

[0212] When an external short circuit occurs in the battery cell 6, the first conductive component 41 melts and fills the first insulating gap P1, which can connect the wall portion 23 and the first electrode terminal 30. Thus, the first electrode terminal 30 and the second electrode terminal 70 are connected through the wall portion 23. The resistance of the wall portion 23 is relatively small, which can reduce the short circuit resistance. A large instantaneous current is generated inside the battery cell 6, which melts the first adapter 61 or other components such as the tab, which helps to reduce the risk of fire and explosion of the battery cell 6 and improve the reliability of the battery cell 6.

[0213] In some embodiments, refer to Figure 3 and Figure 10The electrode assembly 10 includes a second tab 13 extending from the main body 11, the second tab 13 having opposite polarities to the first tab 12. The battery cell 6 includes a second electrode terminal 70 and a second conductive component 42. The second electrode terminal 70 is connected to the second tab 13 and is insulated from the wall portion 23, forming a second insulating gap P2 between the second electrode terminal 70 and the wall portion 23. The second conductive component 42 is connected to the second electrode terminal 70 and is insulated from the wall portion 23. At least a portion of the second conductive component 42 is exposed within the second insulating gap P2. The melting point of the second conductive component 42 is lower than the melting point of the second electrode terminal 70.

[0214] The structure and materials of the second conductive component 42 may be the same as or similar to those of the first conductive component 41, and will not be described in detail here.

[0215] The positional relationship between the second conductive component 42 and the second electrode terminal 70, and the positional relationship between the second conductive component 42 and the wall portion 23, can be the same as the positional relationship between the first conductive component 41 and the first electrode terminal 30, and the positional relationship between the first conductive component 41 and the wall portion 23, respectively, and will not be described again here.

[0216] When an external short circuit occurs in battery cell 6, the second electrode terminal 70 heats up and can quickly melt the second conductive component 42. The melted second conductive component 42 fills at least part of the space in the second insulating gap P2, thereby connecting the second electrode terminal 70 and the wall portion 23. Thus, the first electrode terminal 30 and the second electrode terminal 70 are directly connected through the wall portion 23, which can reduce the short-circuit resistance, increase the short-circuit current, and melt some overcurrent components (such as adapter plates, tabs, etc.) in the current loop. This helps to reduce the risk of battery cell 6 catching fire and exploding, and improve the reliability of battery cell 6.

[0217] In some embodiments, the battery cell 6 further includes a second adapter 62, which is connected to the second tab 12 and the second electrode terminal 70.

[0218] The second adapter 62 can be a sheet-like structure with relatively uniform thickness. The second adapter 62 has a large current-carrying area, which is beneficial to improving the current-carrying capacity of the battery cell 6.

[0219] The melting point of the second conductive component 42 can be lower than that of the second adapter 62. In the event of an external short circuit in the battery cell 6, the second conductive component 42 can preferentially melt upon heating, thereby short-circuiting the wall portion 23 and the second electrode terminal 70. The battery cell 6 will instantly generate a large short-circuit current, which can melt the second tab 13 or the second adapter 62, breaking the current circuit. This embodiment does not require thinning or narrowing the second adapter 62 or other current-carrying components, and will not affect the performance of the battery cell 6 under normal conditions.

[0220] According to some embodiments of this application, this application also provides a battery device 2, which includes a plurality of battery cells 6 provided in any of the above embodiments.

[0221] According to some embodiments of this application, this application also provides an electrical device, which includes a battery device 2 of any of the above embodiments, the battery device 2 being used to provide electrical energy.

[0222] The battery cell 6 provided in this embodiment includes an electrode assembly 10, a housing 20, a first electrode terminal 30, and a first conductive component 41 made of a low-melting-point metal. The housing 20 includes a wall portion 23, and the wall portion 23 has a first electrode lead-out hole 231. The electrode assembly 10 is housed within the housing 20 and includes a main body portion 11 and a first electrode tab 12 extending from the main body portion 11. The first electrode terminal 30 is disposed in the first electrode lead-out hole 231 and is insulated from the wall portion 23. The first conductive component 41 includes any one of lead-bismuth alloy, metallic tin, metallic bismuth, and metallic lead.

[0223] In some examples, at least a portion of the first electrode terminal 30 is accommodated in the first electrode lead-out hole 231, and a first insulating gap P1 is formed between the outer peripheral surface of the first electrode terminal 30 and the hole wall 231a of the first electrode lead-out hole 231. A first conductive member 41 is accommodated in the first insulating gap P1, and a portion of the first insulating gap P1 is located between the first conductive member 41 and the wall portion 23. Along the thickness direction X of the wall portion 23, both ends of the first conductive member 41 are flush with both ends of the first insulating gap P1. The volume of the first conductive member 41 is V1, and the volume of the first insulating gap P1 is V0, where 0.3 ≤ V1 / V0 ≤ 0.8. Optionally, 0.5 ≤ V1 / V0 ≤ 0.7.

[0224] In other examples, the first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32. At least a portion of the first terminal portion 31 is accommodated in a first electrode lead-out hole 231. The second terminal portion 32 protrudes from the outer peripheral surface 31a of the first terminal portion 31. Along the thickness direction X of the wall portion 23, the second terminal portion 32 is located on the side of the wall portion 23 facing away from the main body portion 11. A first conductive member 41 is embedded in the second terminal portion 32. The battery cell 6 includes a second insulating member 53. Along the thickness direction X of the wall portion 23, at least a portion of the second insulating member 53 is sandwiched between the wall portion 23 and the second terminal portion 32. The second insulating member 53 has a second through hole 531. The second through hole 531 penetrates the second insulating member 53 along the thickness direction X of the wall portion 23, forming a first insulating gap P1. Along the thickness direction X of the wall portion 23, the projection of the second through hole 531 and the projection of the first conductive member 41 partially overlap. The volume of the first conductive component 41 is V2, and the volume of the first insulating gap P1 is V0′, where 1 < V2 / V0′ ≤ 2. Optionally, 1.3 ≤ V2 / V0′ ≤ 1.8.

[0225] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer casing includes a wall portion, wherein the wall portion is provided with a first electrode lead-out hole; An electrode assembly, housed within the housing, the electrode assembly comprising a main body and a first tab extending from the main body; A first electrode terminal is disposed in the first electrode lead-out hole and is insulated from the wall portion, and a first insulating gap is formed between the first electrode terminal and the wall portion; as well as A first conductive component is connected to the first electrode terminal and insulated from the wall portion, at least a portion of the first conductive component is exposed in the first insulating gap, and the melting point of the first conductive component is lower than the melting point of the first electrode terminal.

2. The battery cell according to claim 1, characterized in that, Along the arrangement direction of the first conductive component and the wall portion, at least a portion of the first insulating gap is located between the first conductive component and the wall portion.

3. The battery cell according to claim 1 or 2, characterized in that, The first insulation gap is an annular gap extending circumferentially along the first electrode terminal.

4. The battery cell according to claim 3, characterized in that, The first conductive component is a ring-shaped component extending circumferentially along the first electrode terminal.

5. The battery cell according to any one of claims 1-4, characterized in that, The volume of the first conductive component is larger than the volume of the first insulating gap.

6. The battery cell according to any one of claims 1-4, characterized in that, At least a portion of the first electrode terminal is accommodated in the first electrode lead-out hole, and the first insulating gap is located between the first electrode terminal and the hole wall of the first electrode lead-out hole; The first conductive component is housed within the first insulating gap.

7. The battery cell according to claim 6, characterized in that, The first conductive component is disposed around the first electrode terminal, and the inner peripheral surface of the first conductive component is attached to the outer peripheral surface of the first electrode terminal.

8. The battery cell according to claim 6 or 7, characterized in that, Along the thickness direction of the wall portion, both ends of the first conductive component are flush with both ends of the first insulating gap. The volume of the first conductive component is V1, and the volume of the insulating gap is V0, where 0.3 ≤ V1 / V0 ≤ 0.8, and optionally, 0.5 ≤ V1 / V0 ≤ 0.

7.

9. The battery cell according to any one of claims 6-8, characterized in that, The first electrode terminal includes a first terminal portion and a second terminal portion. At least a portion of the first terminal portion is accommodated in the first electrode lead-out hole. The second terminal portion protrudes from the outer peripheral surface of the first terminal portion. Along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion. The battery cell includes a seal, and a portion of the seal is sandwiched between the wall and the second terminal portion along the thickness direction of the wall portion; Along the direction from the main body to the wall, the seal covers the first insulating gap.

10. The battery cell according to claim 9, characterized in that, The melting point of the first conductive component is lower than that of the seal.

11. The battery cell according to any one of claims 1-5, characterized in that, The first electrode terminal includes a first terminal portion and a second terminal portion. At least a portion of the first terminal portion is accommodated in the first electrode lead-out hole. The second terminal portion protrudes from the outer peripheral surface of the first terminal portion and is located on one side of the wall portion along its own thickness direction. The first conductive component is connected to the second terminal portion, the first insulating gap is formed between the wall portion and the second terminal portion, and the volume of the first conductive component is larger than the volume of the first insulating gap.

12. The battery cell according to claim 11, characterized in that, Along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion; The battery cell includes a first insulating member. At least a portion of the first insulating member is sandwiched between the wall portion and the second terminal portion along the thickness direction of the wall portion. The first insulating member has a first through hole that penetrates the first insulating member along the thickness direction of the wall portion and forms the first insulating gap.

13. The battery cell according to claim 11, characterized in that, Along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion facing the main body portion; The battery cell includes a first insulating member and a sealing member. Along the thickness direction of the wall portion, at least a portion of the first insulating member is sandwiched between the wall portion and the second terminal portion, and a portion of the sealing member is sandwiched between the wall portion and the second terminal portion. The sealing member is spaced apart on the side of the first insulating member near the first terminal portion. The sealing member, the first insulating member, the second terminal portion, and the wall portion together form the first insulating gap.

14. The battery cell according to claim 13, characterized in that, The melting point of the first conductive component is lower than that of the first insulating component and the sealing component.

15. The battery cell according to claim 11, characterized in that, Along the thickness direction of the wall portion, the second terminal portion is located on the side of the wall portion opposite to the main body portion; The battery cell includes a second insulating member. At least a portion of the second insulating member is sandwiched between the wall portion and the second terminal portion along the thickness direction of the wall portion. The second insulating member has a second through hole that penetrates the second insulating member along the thickness direction of the wall portion and forms the first insulating gap.

16. The battery cell according to claim 15, characterized in that, The melting point of the first conductive component is lower than the melting point of the second insulating component.

17. The battery cell according to any one of claims 11-16, characterized in that, At least a portion of the first conductive component is embedded in the second terminal portion.

18. The battery cell according to claim 17, characterized in that, Along the direction from the second terminal portion toward the wall portion, the first conductive component does not extend beyond the surface of the second terminal portion facing the wall portion.

19. The battery cell according to claim 18, characterized in that, The volume of the first conductive component is V2, the volume of the first insulating gap is V0′, 1<V2 / V0′≤2, and optionally, 1.3≤V2 / V0′≤1.

8.

20. The battery cell according to any one of claims 17-19, characterized in that, Along the thickness direction of the wall portion, the projection of the first conductive component and the projection of the first insulating gap partially overlap.

21. The battery cell according to claim 20, characterized in that, The area of ​​the overlapping portion of the projection of the first conductive component and the projection of the insulating gap is S1, and the projected area of ​​the insulating gap is S2, where 0 < S1 / S2 ≤ 0.9, and optionally, 0.1 < S1 / S2 ≤ 0.

5.

22. The battery cell according to any one of claims 1-21, characterized in that, The melting point of the first conductive component is less than or equal to 400°C.

23. The battery cell according to any one of claims 1-22, characterized in that, The first conductive component includes any one of lead-bismuth alloy, metallic tin, metallic bismuth, and metallic lead.

24. The battery cell according to any one of claims 1-23, characterized in that, The electrode assembly further includes a second electrode tab extending from the main body, the second electrode tab having opposite polarity to the first electrode tab; The battery cell includes a second electrode terminal, which is electrically connected to the wall portion and the second tab.

25. The battery cell according to any one of claims 1-23, characterized in that, The electrode assembly includes a second electrode tab extending from the main body, the second electrode tab having opposite polarity to the first electrode tab; The battery cell includes a second electrode terminal and a second conductive component. The second electrode terminal is connected to the second tab and is insulated from the wall portion. A second insulating gap is formed between the second electrode terminal and the wall portion. The second conductive component is connected to the second electrode terminal and is insulated from the wall portion. At least a portion of the second conductive component is exposed in the second insulating gap. The melting point of the second conductive component is lower than the melting point of the second electrode terminal.

26. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1-25.

27. An electrical appliance, characterized in that, Includes the battery device according to claim 26, the battery device being used to provide electrical energy.

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