Battery monomer, battery and electric equipment

Abstract

The embodiment of the invention discloses a battery monomer, a battery and electric equipment. The battery cell includes: a first wall provided with a pressure relief mechanism; the electrode assembly is a cylinder, and the orthographic projection, facing the first wall, of the axis of the electrode assembly is located in the area, where the pressure relief mechanism is located, of the first wall. According to the battery monomer, the battery and the electric equipment provided by the embodiment of the invention, the reliability of the battery monomer can be improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. In this context, electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] In the development of battery technology, in addition to improving the performance of the battery, safety issues are also a problem that cannot be ignored. If the safety of the battery cannot be guaranteed, the battery cannot be used. Therefore, how to enhance the safety of the battery is an urgent technical problem in battery technology. Summary of the Invention

[0004] Embodiments of the present application provide a battery cell, a battery, and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, a battery cell is provided. The battery cell includes: a first wall provided with a pressure relief mechanism; an electrode assembly, which is a cylinder, and the projection of the axis of the electrode assembly on the first wall is located in the area where the pressure relief mechanism of the first wall is located.

[0006] In the embodiments of the present application, for a cylindrical electrode assembly, there are usually voids in the area close to the axis of the electrode assembly. Therefore, if the projection of the axis of the electrode assembly on the first wall is located in the area where the pressure relief mechanism on the first wall is located, at least part of the void in the central area of the electrode assembly can correspond to the pressure relief mechanism, which can reduce the influence of the electrode assembly on the pressure relief mechanism. In the case of thermal runaway of the battery cell, the pressure relief mechanism can be actuated quickly to reduce the pressure and temperature inside the battery cell as soon as possible, reduce the risk of thermal diffusion and battery explosion, and improve the reliability of the battery.

[0007] In some embodiments, the axis of the electrode assembly passes through the center of the pressure relief mechanism. The void in the central area of the electrode assembly can better correspond to the pressure relief mechanism, that is, the central through-hole can better correspond to the pressure relief mechanism. For example, the entire area of the projection of the central through-hole on the first wall can be located in the area where the pressure relief structure is located, which can further reduce the influence of the electrode assembly on the pressure relief mechanism and improve the reliability of the battery cell.

[0008] In some embodiments, the pressure relief mechanism is located in the central region of the first wall. The orthographic projection of the axis of the electrode assembly onto the first wall is located in the region where the pressure relief mechanism of the first wall is located. By further setting the pressure relief mechanism in the central region of the first wall, the axis of the electrode assembly is also close to the central region of the first wall, that is, the electrode assembly is arranged corresponding to the central region of the first wall, which can not only improve the utilization rate of the internal space of the battery cell, but also facilitate processing and assembly.

[0009] In some embodiments, the battery cell further includes: an electrode terminal, which is arranged on the first wall, and the pressure relief mechanism is arranged on the electrode terminal. Arranging the pressure relief mechanism on the electrode terminal can reduce the space on the first wall occupied by the electrode terminal and the pressure relief mechanism. Especially when the area of the first wall is limited, it can improve the structural integration degree, and the structure is simple and easy to implement.

[0010] In some embodiments, the central axis of the electrode terminal passes through the center of the pressure relief mechanism. In this way, the flexibility of the size setting of the pressure relief mechanism can be improved, and the region of the electrode terminal can be reasonably utilized.

[0011] In some embodiments, the electrode terminal is provided with a first groove with an opening facing the outside of the battery cell, and at least part of the pressure relief mechanism is located in the first groove, and the pressure relief mechanism is used to seal the opening of the first groove. Setting the first groove on the electrode terminal can reduce the weight of the electrode terminal and improve the structural stability between the electrode terminal and the first wall where it is located; moreover, arranging at least part of the pressure relief mechanism in the first groove can not only use the pressure relief mechanism to seal the opening of the first groove, but also save the space occupied by the electrode terminal and the pressure relief mechanism, and improve the energy density of the battery.

[0012] In some embodiments, the pressure relief mechanism includes a second groove with an opening facing the outside of the battery cell, and a pressure relief area is provided on the bottom wall of the second groove. On the one hand, the second groove can reduce the overall weight of the pressure relief mechanism, and thus reduce the weight of the battery cell; on the other hand, setting the pressure relief area on the bottom wall of the second groove can thin the pressure relief area and reduce the structural strength of the pressure relief area, so that when the internal pressure or temperature of the battery cell exceeds a predetermined threshold, the pressure relief mechanism can be quickly damaged at the pressure relief area, timely discharge the internal pressure of the battery cell or reduce the internal temperature of the battery cell, reduce the risk of thermal diffusion, and improve the reliability of the battery cell and the battery.

[0013] In some embodiments, a central through-hole is provided at the center of the electrode assembly, and the orthographic projection of the central through-hole onto the first wall is located within the orthographic projection of the pressure relief area onto the first wall. This can reduce the influence of the electrode assembly on the pressure relief area. For example, it can reduce the risk of the tab of the electrode assembly overlapping the pressure relief area, reduce the corrosion of the pressure relief area by the tab, and increase the service life of the pressure relief area. Also, in the case of thermal runaway of the battery cell, the pressure relief area can be actuated quickly to rapidly reduce the pressure and temperature inside the battery cell, reduce the risk of thermal diffusion and battery explosion, and improve the reliability of the battery.

[0014] In some embodiments, the pressure relief mechanism includes a protective sheet for protecting the pressure relief area, and at least a part of the protective sheet is located within the second groove. The protective sheet is located on the side of the pressure relief area away from the inside of the battery cell to protect the pressure relief area from the influence of the external environment or external components of the battery cell, thereby increasing the service life of the pressure relief mechanism. Moreover, setting at least a part of the protective sheet within the second groove can save the space occupied by the pressure relief mechanism to improve the space utilization rate of the battery.

[0015] In some embodiments, the protective sheet is provided with a third through-hole, which can be used to balance the pressures on both sides of the protective sheet and increase the service life of the pressure relief mechanism.

[0016] In some embodiments, the electrode terminal is provided with a first through-hole that penetrates the bottom wall of the first groove. In this way, when thermal runaway occurs in the battery cell, the emissions inside the battery cell can quickly pass through the electrode terminal and act on the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, thereby quickly discharging the gas inside the battery cell and reducing the temperature inside the battery cell, reducing the risk of thermal diffusion, and improving the reliability of the battery cell and the battery. Also, when the pressure relief mechanism is used to seal the first groove, it can also be used to seal the first through-hole.

[0017] In some embodiments, the central axis of the first through-hole passes through the center of the pressure relief mechanism, so that at least a part of the area of the first through-hole is disposed opposite the pressure relief mechanism, improving the actuation efficiency of the pressure relief mechanism during thermal runaway of the battery cell, quickly discharging the gas inside the battery cell and reducing the temperature inside the battery cell, reducing the risk of thermal diffusion, and improving the reliability of the battery cell and the battery.

[0018] In some embodiments, the center of the electrode assembly has a central through-hole, and the aperture of the first through-hole is less than or equal to the aperture of the central through-hole. On the one hand, since the aperture of the first through-hole is small, the area of the bottom wall of the first groove other than the first through-hole is relatively large, and part of the pressure relief mechanism can be blocked by this part of the area to protect the pressure relief mechanism from being affected by the internal part of the battery cell. On the other hand, when the first through-hole is a liquid injection hole, setting the aperture of the first through-hole to be small can make the electrolyte more concentrated and injected into the electrode assembly after passing through the first through-hole, reduce splashing, and improve the liquid injection efficiency.

[0019] In some embodiments, the battery cell further includes: a connection member for electrically connecting to the electrode terminal and the tab of the electrode assembly respectively. The connection member is provided with a second through-hole, and in the axial direction of the first through-hole, the orthographic projection of the second through-hole at least partially overlaps with the orthographic projection of the first through-hole.

[0020] When thermal runaway occurs in the battery cell, the emissions inside the battery cell can quickly pass through the connection member through the second through-hole, then pass through the electrode terminal through the first through-hole and act on the pressure relief mechanism, so that the pressure relief mechanism can be actuated in time, and then quickly discharge the gas inside the battery cell and reduce the temperature inside the battery cell, reduce the risk of thermal diffusion, and improve the reliability of the battery cell and the battery. And, when the first through-hole is used as a liquid injection hole, under the action of gravity, at least part of the injected electrolyte can directly pass through the first through-hole and the second through-hole in sequence and enter the battery cell, avoiding excessive electrolyte flowing to other positions of the connection member, which is more conducive to improving the liquid injection efficiency.

[0021] In some embodiments, the central axis of the second through-hole coincides with the central axis of the first through-hole. In this way, there is no offset between the first through-hole and the second through-hole along the axial direction of the first through-hole. On the one hand, it can make the emissions pass through the connection member and the electrode terminal more quickly when thermal runaway occurs in the battery cell. On the other hand, it can also make the electrolyte pass through the first through-hole and the second through-hole more and faster and enter the battery cell, avoiding excessive electrolyte splashing to other positions, and further improving the liquid injection rate.

[0022] In some embodiments, the battery cell further includes: a sealing structure, at least part of the area of the sealing structure is located in the first through-hole to seal the first through-hole. Sealing the first through-hole through the sealing structure can reduce the overflow of the internal electrolyte and reduce the corrosion of the pressure relief mechanism by the electrolyte. For example, it can reduce the corrosion of the pressure relief area and improve the service life of the pressure relief mechanism.

[0023] In some embodiments, the first through-hole is the liquid injection hole of the battery cell, so there is no need to additionally provide a liquid injection hole at other positions on the first wall, saving space, improving the integration of the first wall, and further improving the space utilization rate of the battery cell, facilitating assembly and processing.

[0024] In some embodiments, a first welding area is provided on a side of the electrode terminal away from the inside of the battery cell, and the first welding area is located around the area where the pressure relief mechanism is located. The first welding area is used for electrically connecting with a bus bar component. This can reduce the influence of the welding on the pressure relief mechanism, improve the structural stability of the pressure relief mechanism, and further improve the stability of the battery cell.

[0025] In some embodiments, the battery cell includes: a housing, which is a hollow structure with an opening; a cover plate for covering the opening of the housing, and the first wall is the cover plate. By covering the opening of the housing with the cover plate, the inside of the battery cell can be isolated from the outside to avoid external influence.

[0026] In some embodiments, the first wall is circular or rectangular for easy processing.

[0027] In a second aspect, a battery is provided, including: the battery cell described in the first aspect or any one of the embodiments in the first aspect.

[0028] In some embodiments, the battery cell includes an electrode terminal, the electrode terminal is disposed on the first wall, the electrode terminal is provided with the pressure relief mechanism, and the battery further includes: a bus bar component for electrically connecting the electrode terminals of multiple battery cells. The bus bar component includes an avoidance opening and a second welding area, the second welding area is located around the avoidance opening, the second welding area is used for electrically connecting with the electrode terminal, and the avoidance opening is used for avoiding at least part of the area of the pressure relief mechanism. The electrical connection between the bus bar component and the electrode terminal can be achieved through the second welding area, and the influence of the welding on the pressure relief mechanism can be reduced through the avoidance opening.

[0029] In some embodiments, the pressure relief mechanism is provided with a protection sheet, and the avoidance opening is used for avoiding the protection sheet. The protection sheet in the embodiments of the present application can be used to protect the pressure relief area of the pressure relief mechanism. The avoidance opening at least avoids the area where the protection sheet is located, which can reduce the damage to the protection sheet, so that the protection sheet can protect the pressure relief area to improve the service life of the pressure relief mechanism.

[0030] In a third aspect, an electrical device is provided, including: a battery, the battery includes multiple battery cells described in the first aspect or any one of the embodiments in the first aspect, and the battery is used to provide electrical energy for the electrical device.

[0031] In some embodiments, the electrical device is a vehicle, a ship or a spacecraft. Brief Description of the Drawings

[0032] Figure 1 Schematic diagram of a vehicle according to an embodiment of the present application;

[0033] Figure 2 Schematic diagram of a partial exploded structure of a battery according to an embodiment of the present application;

[0034] Figure 3 Schematic diagram of an exploded structure of a battery cell according to an embodiment of the present application;

[0035] Figure 4 Schematic diagram of an exploded structure of a battery cell according to another embodiment of the present application;

[0036] Figure 5 Top view schematic diagram of a battery cell according to another embodiment of the present application;

[0037] Figure 6 Partial cross-sectional schematic diagram of a battery cell according to another embodiment of the present application;

[0038] Figure 7 Another partial cross-sectional schematic diagram of a battery cell according to another embodiment of the present application;

[0039] Figure 8 Partial structure schematic diagram of a battery cell according to another embodiment of the present application;

[0040] Figure 9 Partial structure exploded schematic diagram of a battery cell according to another embodiment of the present application;

[0041] Figure 10 Structure schematic diagram of a connecting member according to another embodiment of the present application;

[0042] Figure 11 Partial structure schematic diagram of a battery according to an embodiment of the present application;

[0043] Figure 12 Structure schematic diagram of a bus bar component according to an embodiment of the present application.

[0044] In the drawings, the drawings are not drawn to actual scale. Detailed Description of the Embodiments

[0045] Next, the technical solutions in the embodiments of the present application will be described with reference to the drawings.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the description of this application in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0048] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0049] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled", and "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] The term "and / or" in this application is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0051] In the embodiments of the present application, the same reference numerals denote the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0052] The term "a plurality of" as used in the present application refers to two or more (including two). Similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of sheets" refers to two or more sheets (including two sheets).

[0053] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging after discharging so that the active material can be used continuously.

[0054] The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application are not limited thereto.

[0055] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through.

[0056] In some embodiments, the positive electrode may include a positive electrode tab, and the positive electrode tab 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.

[0057] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0058] In some embodiments, the negative electrode may include a negative electrode tab, and the negative electrode tab 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] As an example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is disposed on any one of the two opposite surfaces of the negative electrode current collector or both.

[0060] In some embodiments, the electrode assembly further includes a separator, and the separator is disposed between the positive electrode and the negative electrode.

[0061] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application does not specifically limit the type of electrolyte, and it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid-state.

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

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

[0064] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be respectively provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are alternately stacked.

[0065] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet is folded to form a plurality of stacked folding segments, and a positive electrode sheet is clamped between adjacent folding segments.

[0066] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folding segments.

[0067] As an example, a plurality of separators can be provided and are respectively disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0068] As an example, the separators can be continuously provided and are disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0069] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0070] In some embodiments, the battery cell can include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc. The housing includes a case and a cover plate.

[0071] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal prism battery, etc. The present application has no special limitation.

[0072] The battery mentioned in the embodiments of the present application can include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, parallel, or in a hybrid connection through a busbar component.

[0073] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0074] In some embodiments, the battery may be a battery pack. The battery pack includes a box body and battery cells, and the battery cells or battery modules are accommodated in the box body.

[0075] In some embodiments, the box body may be part of the chassis structure of a vehicle. For example, part of the box body may become at least part of the floor of the vehicle, or part of the box body may become at least part of the cross beams and longitudinal beams of the vehicle.

[0076] The development of battery technology needs to consider various design factors simultaneously. For example, performance parameters such as energy density, cycle life, discharge capacity, charge-discharge rate, etc. In addition, the safety of the battery also needs to be considered. For a battery, the main safety hazards come from the charging and discharging processes. In order to improve the safety performance of the battery, a pressure relief mechanism is generally provided for the battery cell. The pressure relief mechanism refers to an element or component that is actuated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold.

[0077] For the convenience of processing, the pressure relief mechanism is usually provided on a wall of the battery cell together with other components. For example, the pressure relief mechanism can usually be located on the same wall as the electrode terminal or the liquid injection hole of the battery cell. Considering that the pressure relief mechanism occupies a relatively small area compared to structures such as electrode terminals, it is usually set in the edge area to avoid other components. For example, when the pressure relief mechanism and the electrode terminal are provided on the same wall, if there is one electrode terminal on this wall, this electrode terminal is usually located in the center position. If there are multiple electrode terminals on this wall, the multiple electrode terminals are usually symmetrically distributed relative to the center of the wall where they are located, and the pressure relief mechanism is usually set at the edge position of the wall where it is located to avoid affecting the electrode terminal. In addition, if the wall where the pressure relief mechanism is located is also provided with a liquid injection hole, the position of the liquid injection hole is usually considered first in terms of liquid injection efficiency. Therefore, the position where the pressure relief mechanism is located is very limited and is usually set at a specific edge position. In this case, for the situation where the battery cell has a cylindrical electrode assembly inside, when the pressure relief mechanism is located at the edge position, the pressure relief mechanism usually also corresponds to the edge position of the electrode assembly. However, when the tab of the cylindrical electrode assembly is processed, the edge of the end face where the tab is located is a flattened area, and there may be a risk that the tab overlaps the pressure relief mechanism, thereby affecting the service life of the battery cell.

[0078] Based on this, the embodiments of the present application provide a battery cell, a battery, and an electrical device. A pressure relief mechanism is provided on the first wall of the battery cell. The electrode assembly inside the battery cell is cylindrical, and the orthogonal projection of the axis of the electrode assembly onto the first wall is located within the area where the pressure relief mechanism is located on the first wall. For a cylindrical electrode assembly, there are usually voids in the area close to the axis of the electrode assembly. Therefore, if the orthogonal projection of the axis of the electrode assembly onto the first wall is located within the area where the pressure relief mechanism is located on the first wall, at least part of the void in the central area of the electrode assembly can correspond to the pressure relief mechanism, which can reduce the influence of the electrode assembly on the pressure relief mechanism, so that in the case of thermal runaway of the battery cell, the pressure relief mechanism can be actuated quickly to reduce the pressure and temperature inside the battery cell as soon as possible, reduce the risk of thermal diffusion and battery explosion, and improve the reliability of the battery.

[0079] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using batteries.

[0080] The electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact drill, a concrete vibrator, a power planer, etc. The embodiments of the present application do not impose special restrictions on the above electrical devices.

[0081] For the convenience of description, the following embodiments take the electrical device as a vehicle as an example for illustration.

[0082] For example, as Figure 1As shown, it is a schematic structural diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc. A motor 40, a controller 30, and a battery 10 can be arranged inside the vehicle 1. The controller 30 is used to control the power supply of the battery 10 to the motor 40. For example, the battery 10 can be arranged at the bottom, the front end, or the rear end of the vehicle 1. The battery 10 can be used for the power supply of the vehicle 1. For example, the battery 10 can be used as the operating power supply of the vehicle 1 and is used for the circuit system of the vehicle 1, such as the working power consumption requirements for starting, navigating, and running the vehicle 1. In another embodiment of the present application, the battery 10 can not only be used as the operating power supply of the vehicle 1 but also as the driving power supply of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0083] For example. Figure 2 The figure shows a partial schematic structural diagram of the battery 10 according to an embodiment of the present application. As Figure 2 shown, the battery 10 according to an embodiment of the present application can include a plurality of battery cells 20 to meet different power usage requirements. The shape of the battery cell 20 according to an embodiment of the present application can be set according to actual applications. For example, the battery cell 20 can be cylindrical as Figure 2 shown, or it can also be a cuboid different from Figure 2 shown or other shapes. The embodiments of the present application are not limited thereto.

[0084] It should be understood that as Figure 2 shown, the battery 10 according to an embodiment of the present application can further include a box body 11. The box body 11 can be used to accommodate a plurality of battery cells 20. The inside of the box body 11 according to an embodiment of the present application is a hollow structure, and a plurality of battery cells 20 are accommodated in the box body 11. The box body 11 can include two parts, which are respectively referred to as a first box body part 111 and a second box body part 112. The first box body part 111 and the second box body part 112 are snapped together. The shapes of the first box body part 111 and the second box body part 112 can be determined according to the shape of the components accommodated inside, for example, according to the shape of the combination of a plurality of battery cells 20 accommodated inside. At least one of the first box body part 111 and the second box body part 112 has an opening. For example, as Figure 2As shown, only one of the first box body part 111 and the second box body part 112 can be a hollow cuboid with an opening, and the other can be plate-shaped to cover the opening. Here, taking the second box body part 112 as a hollow cuboid with an opening and the first box body part 111 as plate-shaped as an example, the first box body part 111 covers the opening of the second box body part 112 to form a box body 11 with a closed chamber, and this chamber can be used to accommodate a plurality of battery cells 20. A plurality of battery cells 20 are placed in the box body 11 formed after the first box body part 111 and the second box body part 112 are buckled together after being connected in parallel, in series, or in a mixed connection combination.

[0085] For another example, different from Figure 2 As shown, the first box body part 111 and the second box body part 112 can also both be hollow cuboids and each have an opening surface, the opening of the first box body part 111 and the opening of the second box body part 112 are arranged opposite to each other, and the first box body part 111 and the second box body part 112 are buckled together to form a box body 11 with a closed chamber, and this chamber can be used to accommodate a plurality of battery cells 20.

[0086] In some embodiments, the battery 10 may further include a busbar component, and the busbar component can be used to achieve electrical connection between a plurality of battery cells 20, such as in parallel, in series, or in a mixed connection. Specifically, the busbar component can achieve electrical connection between battery cells 20 by connecting the electrode terminals 214 of the battery cells 20; alternatively, the busbar component can also achieve electrical connection between battery cells 20 by connecting other components of the battery cells 20. For example, the busbar component can be electrically connected to the sealing structure or the housing of the battery cell 20, etc., so as to further achieve electrical connection between battery cells 20. Further, the busbar component can be fixed to the corresponding components of the battery cell 20 by welding. For example, it can be fixed to the electrode terminals 214, the sealing structure, or the housing, etc. by welding, and the embodiments of the present application are not limited to this.

[0087] Figure 3 and Figure 4 respectively show the exploded structural schematic diagrams of the battery cell 20 in different embodiments of the present application; Figure 5 shows a top view schematic diagram of a battery cell 20 in an embodiment of the present application. For example, the Figure 5 can be Figure 4 the top view schematic diagram of the battery cell 20 shown; Figure 6 shows a cross-sectional schematic diagram of a battery cell 20 in an embodiment of the present application. For example, the Figure 6 can be Figure 4 the cross-sectional schematic diagram of the battery cell 20 shown, Figure 6 can be a cross-sectional schematic diagram along the Figure 5 A-A' direction shown, and this cross-section passes through the central axis of the battery cell 20. As Figures 3 to 6As shown in the figure, the battery cell 20 of the embodiment of the present application includes: a first wall 201 and an electrode assembly 22. Among them, the first wall 201 is provided with a pressure relief mechanism 213; the electrode assembly 22 is a cylinder, and the orthogonal projection of the axis L of the electrode assembly 22 on the first wall 201 is located in the area where the pressure relief mechanism 213 of the first wall 201 is located.

[0088] It should be understood that the first wall 201 of the battery cell 20 of the embodiment of the present application is provided with a pressure relief mechanism 213, which refers to an element or component that is actuated when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold to release the internal pressure or temperature. This threshold design varies according to different design requirements. This threshold may depend on one or several materials among the positive electrode plate, negative electrode plate, electrolyte, and separator in the battery cell 20.

[0089] The "actuation" mentioned in the present application means that the pressure relief mechanism 213 generates an action or is activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The actions generated by the pressure relief mechanism 213 may include but are not limited to: at least a part of the pressure relief mechanism 213 ruptures, breaks, is torn, or opens, etc. When the pressure relief mechanism 213 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged outward from the actuated part as emissions. In this way, the battery cell 20 can be depressurized and de-temperatureed under a controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0090] The emissions from the battery cell 20 mentioned in the present application include but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0091] The battery cell 20 of the embodiment of the present application may include one or more electrode assemblies 22. The electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs. The electrode assembly 22 includes a positive electrode plate, a negative electrode plate, and a separator, and the separator is used to separate the positive electrode plate and the negative electrode plate. The positive electrode plate, the negative electrode plate, and the separator are all strip-shaped structures, and the positive electrode plate, the negative electrode plate, and the separator are wound together to form a wound structure, where the wound structure is a cylindrical structure.

[0092] From the external shape of the electrode assembly 22, Figures 3 to 6For example, the electrode assembly 22 in the embodiments of the present application may include a tab 222 and a main body portion 221. Among them, the tab 222 of the electrode assembly 22 may include a positive tab and a negative tab. The positive tab may be formed by a portion of the positive electrode plate where the positive active material layer is not coated, and the negative tab may be formed by a portion of the negative electrode plate where the negative active material layer is not coated. The main body portion 221 is the portion of the electrode assembly 22 where active ions (such as lithium ions) are inserted and extracted back and forth between the positive electrode plate and the positive electrode plate. And, the two tabs 222 of the electrode assembly 22 may be respectively located on different end faces of the electrode assembly 22. For example, as Figures 3 to 6 shown, in the embodiments of the present application, an example is given where the two tabs 222 of the electrode assembly 22 are respectively located on two oppositely arranged end faces.

[0093] It should be understood that the electrode assembly 22 in the embodiments of the present application is a cylinder, that is, the main body portion 221 of the electrode assembly 22 is a cylinder, and the tabs 222 may be located on the two bottom surfaces of the cylinder. The axis L of the cylindrical electrode assembly 22 in the embodiments of the present application is the straight line where the connection line of the centers of the two circular bottom surfaces of the cylinder is located. For example, in the embodiments of the present application, an example is mainly given where the direction of the axis L of the electrode assembly 22 is parallel to the height direction X of the battery cell 20, and the height direction X of the battery cell 20 is also the height direction X of the electrode assembly 22.

[0094] The first wall 201 in the embodiments of the present application may be any wall of the battery cell 20. However, since the pressure relief mechanism 213 is provided on the first wall 201, and the orthographic projection of the axis L of the electrode assembly 22 onto the first wall 201 is located in the area where the pressure relief mechanism 213 of the first wall 201 is located, therefore, the first wall 201 where the pressure relief mechanism 213 is located is the wall facing any one of the two bottom surfaces of the electrode assembly 22. In some embodiments, the battery cell 20 may include one or more first walls 201. For example, only one of the two bottom surfaces of the battery cell 20 may have a first wall 201, that is, only one bottom surface is provided with a pressure relief mechanism 213; or, the two bottom surfaces of the battery cell 20 may be two first walls 201, and each first wall 201 is provided with a pressure relief mechanism 213, but the embodiments of the present application are not limited thereto.

[0095] In the embodiments of the present application, for the cylindrical electrode assembly 22, due to the limitation of the processing technology, the area near the axis L of the electrode assembly 22 usually has voids. For example, as Figures 3 to 6As shown, the gap in the region close to the axis L of the electrode assembly 22 can be a central through-hole 223 that penetrates the electrode assembly 22 along the height direction X of the electrode assembly 22. Therefore, if the positive projection of the axis L of the electrode assembly 22 towards the first wall 201 is located in the region where the pressure relief mechanism 213 is located on the first wall 201, at least a partial region of the gap in the central region of the electrode assembly 22 can correspond to the pressure relief mechanism 213, that is, at least a partial region of the central through-hole 223 can correspond to the pressure relief mechanism 213. This can reduce the influence of the electrode assembly 22 on the pressure relief mechanism 213. For example, it can reduce the risk of the tab 222 of the electrode assembly 22 overlapping the pressure relief mechanism 213, reduce the corrosion of the tab 222 on the pressure relief mechanism 213, and improve the service life of the pressure relief mechanism 213. Also, in the case of thermal runaway of the battery cell 20, the pressure relief mechanism 213 can be actuated quickly to reduce the pressure and temperature inside the battery cell 20 as soon as possible, reduce the risk of thermal diffusion and causing the explosion of the battery 10, and improve the reliability of the battery 10.

[0096] It should be understood that the battery cell 20 of the embodiment of the present application can be flexibly set according to actual applications, and the battery cell 20 can be of any shape. For example, the battery cell 20 can be an axisymmetric structure or a non-axisymmetric structure. For example, the battery cell 20 can be a prism to facilitate the assembly of multiple battery cells 20. For example, the battery cell 20 can be a straight prism or an oblique prism.

[0097] Moreover, the shape of the housing 21 of the battery cell 20 can be the same as or different from the shape of the electrode assembly 22. For example, when the electrode assembly 22 of the embodiment of the present application is a cylinder, the housing 21 of the battery cell 20 can also be a cylinder structure to increase the space occupancy rate of the electrode assembly 22 in the battery cell; or, the housing 21 of the battery cell 20 can also be a cuboid structure for easy processing. For the sake of description, the embodiment of the present application mainly takes the cylindrical housing 21 as an example for description, but the embodiment of the present application is not limited thereto.

[0098] In the embodiment of the present application, the shape of the first wall 201 of the embodiment of the present application can be flexibly set according to actual applications, that is, for battery cells 20 of different shapes, the shape of the first wall 201 is also different. For example, the first wall 201 can be circular or rectangular for easy processing.

[0099] In some embodiments, the battery cell 20 of the embodiment of the present application further includes: a housing 211 and a cover plate 212. Wherein, the housing 211 is a hollow structure with an opening 2111; the cover plate 212 is used to cover the opening 2111 of the housing 211. The hollow structure inside the housing 211 can be used to accommodate the electrode assembly 22. By covering the opening 2111 of the housing 211 with the cover plate 212, the inside of the battery cell 20 can be isolated from the outside to avoid external influence.

[0100] The housing 211 of the embodiment of the present application may be a hollow structure including at least one opening 2111. Specifically, if the housing 211 is a hollow structure with one opening 2111, the corresponding cover plate 212 may be set to one to cover one opening 2111 of the housing 211; if the housing 211 is a hollow structure with two openings 2111, for example, as Figures 3 to 6 shown, the housing 211 has two oppositely arranged openings 2111, then the cover plates 212 may be set to two, and the two cover plates 212 respectively cover the two openings 2111 of the housing 211.

[0101] The material of the housing 211 can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The housing 211 can be of any shape, such as a cylinder, a cuboid, etc. Exemplarily, in the Figures 3 to 6 embodiment of the present application, the housing 211 is a cylinder; exemplarily, the housing 211 has two openings 2111, and the two openings 2111 are the two opposite bottom surfaces of the housing 211. This structure with openings at both ends facilitates the assembly of the internal electrode assembly 22. The electrode assembly 22 can enter the housing 211 through any one of the openings 2111, which can improve the processing efficiency of the battery cell 20.

[0102] The cover plate 212 of the embodiment of the present application is a component for covering the opening 2111 of the housing 211 to isolate the internal environment of the battery cell 20 from the external environment. The material of the cover plate 212 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the cover plate 212 can be the same as or different from that of the housing 211.

[0103] It should be understood that the shape of the cover plate 212 can be adapted to the shape of the housing 211. For example, when the housing 211 is a cuboid structure, the cover plate 212 can be an approximately plate-like structure with a rectangular surface adapted to the housing 211, or it can also be a hollow cuboid structure with one end open, so that after the cover plate 212 and the housing 211 are covered, a cuboid battery cell 20 is formed. Another example, as Figures 3 to 6 shown, when the housing 211 is a cylinder, the cover plate 212 can also be an approximately plate-like structure with a circular shape; or, different from Figures 3 to 6 , the cover plate 212 can also be a groove structure with a circular bottom wall, so that after the cover plate 212 and the housing 211 are covered, a cylindrical battery cell 20 is formed. The embodiment of the present application is not limited to this.

[0104] Exemplarily, for the sake of description, in the embodiments of the present application, a cylindrical housing 211 is taken as an example, and the two opposite bottom surfaces of the housing 211 have openings 2111; correspondingly, two cover plates 212 respectively cover the two openings 2111. In some embodiments, the first wall 201 of the embodiments of the present application may be the cover plate 212, that is, at least one of the two cover plates 212 included in the battery cell 20 may be provided with a pressure relief mechanism 213, which is convenient for processing.

[0105] In some embodiments, the axis L of the electrode assembly 22 passes through the center of the pressure relief mechanism 213, so that the void in the central region of the electrode assembly 22 can better correspond to the pressure relief mechanism 213, that is, the central through hole 223 can better correspond to the pressure relief mechanism 213. For example, the entire region of the orthographic projection of the central through hole 223 towards the first wall 201 can be located within the region where the pressure relief mechanism 213 is located, which can further reduce the influence of the electrode assembly 22 on the pressure relief mechanism 213 and improve the reliability of the battery cell 20.

[0106] In some embodiments, the pressure relief mechanism 213 is located in the central region of the first wall 201. For example, taking the surface of the first wall 201 as a circle, the center of the first wall 201 is the center O, and the central region of the first wall 201 is the region close to the center O, then the center O can coincide or be substantially coincident with the center of the region where the pressure relief mechanism 213 of the first wall 201 is located, so that the pressure relief mechanism 213 is located in the central region of the first wall 201. For another example, if the surface of the first wall 201 is a rectangle, the center of the first wall 201 is the intersection of the diagonals of the rectangle, and the central region of the first wall 201 is the region close to the intersection.

[0107] The orthographic projection of the axis L of the electrode assembly 22 towards the first wall 201 is located in the region where the pressure relief mechanism 213 of the first wall 201 is located. By further setting the pressure relief mechanism 213 in the central region of the first wall 201, the axis L of the electrode assembly 22 is also close to the central region of the first wall 201, that is, the electrode assembly 22 is arranged corresponding to the central region of the first wall 201, which can not only improve the internal space utilization rate of the battery cell 20, but also facilitate processing and assembly.

[0108] In the embodiments of the present application, the pressure relief mechanism 213 can be directly provided on the first wall 201. Or, as Figures 3 to 6As shown, the pressure relief mechanism 213 of the embodiment of the present application can also be provided on other components of the first wall 201 to improve the integration of the battery cell 20. For example, the battery cell 20 further includes: an electrode terminal 214, the electrode terminal 214 is provided on the first wall 201, and the pressure relief mechanism 213 is provided on the electrode terminal 214. Providing the pressure relief mechanism 213 on the electrode terminal 214 can reduce the space occupied by the electrode terminal 214 and the pressure relief mechanism 213 on the first wall 201. Especially when the area of the first wall 201 is limited, it can improve the structural integration, and the structure is simple and easy to implement.

[0109] Further, the central axis of the electrode terminal 214 passes through the center of the pressure relief mechanism 213. In this way, the flexibility of the size setting of the pressure relief mechanism 213 can be improved, and the area of the electrode terminal 214 can be reasonably utilized. Among them, the direction of the central axis of the electrode terminal 214 in the embodiment of the present application is the same as the direction of the axis L of the electrode assembly 22.

[0110] It should be understood that the electrode terminal 214 of the embodiment of the present application is used to be electrically connected to the electrode assembly 22 inside the battery cell 20 to output the electric energy of the battery cell 20. As Figures 3 to 6 shown, the battery cell 20 may include at least two electrode terminals 214. The at least two electrode terminals 214 may include at least one positive electrode terminal and at least one negative electrode terminal. The positive electrode terminal is used to be electrically connected to the positive electrode tab of the electrode assembly 22, and the negative electrode terminal is used to be electrically connected to the negative electrode tab of the electrode assembly 22. The positive electrode terminal and the positive electrode tab can be directly connected or indirectly connected. The negative electrode terminal and the negative electrode tab can be directly connected or indirectly connected. Exemplarily, the positive electrode terminal can be electrically connected to the positive electrode tab through a connecting member 23, and the negative electrode terminal can also be electrically connected to the negative electrode tab through a connecting member 23.

[0111] It should be understood that different electrode terminals 214 may be located on the same wall or different walls of the battery cell 20. For example, in the embodiment of the present application, taking the battery cell 20 including two electrode terminals 214 as an example, as Figures 3 to 6 shown, the two electrode terminals 214 may also be located on different walls, that is, corresponding to the setting manner of the tabs 222, multiple electrode terminals 214 of the battery cell 20 may be respectively provided on two opposite end faces, for example, may be respectively provided on two opposite cover plates 212, so that each tab 222 can be electrically connected to a corresponding electrode terminal 214, but the embodiment of the present application is not limited thereto.

[0112] For ease of explanation, hereinafter, with reference to the accompanying drawings, mainly taking the cylindrical battery cell 20 as an example, and taking the first wall 201 as the cover plate 212, and the electrode terminal 214 of the cover plate 212 being provided with a pressure relief mechanism 213 as an example, a detailed description will be given, but the embodiments of the present application are not limited thereto.

[0113] The structure of the electrode terminal 214 and the structure of the pressure relief mechanism 213 in the embodiments of the present application can be flexibly set according to actual applications. Examples will be given hereinafter with reference to the accompanying drawings.

[0114] Figure 7 A cross-sectional schematic view of the first wall 201 provided with the electrode terminal 214 in the embodiments of the present application is shown. In comparison Figure 7 and Figure 6 , Figure 7 the pressure relief mechanism 213 is not shown in the cross-sectional schematic view shown.

[0115] In some embodiments, as Figures 3 to 7 shown, the electrode terminal 214 is provided with a first groove 2141 with an opening facing the outside of the battery cell. At least part of the pressure relief mechanism 213 is located in the first groove 2141, and the pressure relief mechanism 213 is used to seal the opening of the first groove 2141. Providing the first groove 2141 on the electrode terminal 214 can reduce the weight of the electrode terminal 214 and improve the structural stability between the electrode terminal 214 and the first wall 201 where it is located; moreover, by disposing at least part of the pressure relief mechanism 213 in the first groove 2141, not only can the pressure relief mechanism 213 be used to seal the opening of the first groove 2141, but also the space occupied by the electrode terminal 214 and the pressure relief mechanism 213 can be saved, and the energy density of the battery 10 can be improved.

[0116] In some embodiments, the pressure relief mechanism 213 includes a second groove 2131 with an opening facing the outside of the battery cell. The bottom wall 2132 of the second groove 2131 is provided with a pressure relief area 2133. On the one hand, the second groove 2131 can reduce the overall weight of the pressure relief mechanism 213, and thus reduce the weight of the battery cell 20; on the other hand, providing the pressure relief area 2133 on the bottom wall 2132 of the second groove 2131 can thin the pressure relief area 2133 and reduce the structural strength of the pressure relief area 2133, so that when the internal pressure or temperature of the battery cell 20 exceeds a predetermined threshold, the pressure relief mechanism 213 can be quickly damaged at the pressure relief area 2133, timely discharge the internal pressure of the battery cell 20 or reduce the internal temperature of the battery cell 20, reduce the risk of thermal diffusion, and improve the reliability of the battery cell 20 and the battery 10.

[0117] It should be understood that the pressure relief area 2133 in the embodiments of the present application is used to break the pressure relief mechanism 213 at the pressure relief area 2133 when the internal pressure or temperature of the battery cell 20 exceeds a predetermined threshold, so as to discharge the internal pressure of the battery cell 20 or reduce the internal temperature of the battery cell 20.

[0118] The pressure relief area 2133 can be implemented in various ways. Exemplarily, as Figures 3 to 7 shown, the pressure relief area 2133 can be provided with a notch 2136 to further thin a local area of the pressure relief area 2133, so as to reduce the structural strength at the notch 2136, so that the notch 2136 can be quickly damaged when the internal pressure or temperature of the battery cell 20 exceeds a predetermined threshold. The position of the notch 2136 can be flexibly set according to actual applications.

[0119] In some embodiments, the pressure relief area 2133 can also be implemented in other ways. For example, the pressure relief area 2133 can also adopt a temperature-sensitive material, so that at least a part of the pressure relief area 2133 can be quickly melted when the internal temperature of the battery cell 20 exceeds a predetermined threshold, thereby discharging the internal pressure of the battery cell 20 in time or reducing the internal temperature of the battery cell 20.

[0120] In some embodiments, the center of the electrode assembly 22 has a central through hole 223, and the orthographic projection of the central through hole 223 facing the first wall 201 is located within the orthographic projection of the pressure relief area 2133 facing the first wall 201. The pressure relief mechanism 213 discharges the internal pressure and temperature of the battery cell 20 through the pressure relief area 2133 when the battery cell 20 is out of control thermally. Therefore, the structural strength of the pressure relief area 2133 is relatively weak. Setting the orthographic projection of the central through hole 223 facing the first wall 201 within the range of the orthographic projection of the pressure relief area 2133 on the first wall 201, that is, the central through hole 223 is arranged corresponding to the pressure relief area 2133, can reduce the influence of the electrode assembly 22 on the pressure relief area 2133. For example, it can reduce the risk that the tab 222 of the electrode assembly 22 overlaps the pressure relief area 2133, reduce the corrosion of the tab 222 on the pressure relief area 2133, and improve the service life of the pressure relief area 2133; it can also enable the pressure relief area 2133 to be actuated quickly in the case of thermal runaway of the battery cell 20, so as to quickly reduce the internal pressure and temperature of the battery cell 20, reduce the risk of thermal diffusion and cause the explosion of the battery 10, and improve the reliability of the battery 10.

[0121] As Figures 3 to 7As shown in the figure, the aperture of the central through-hole 223 of the electrode assembly 22 in the embodiment of the present application is R1. Along the direction where the aperture R1 of the central through-hole 223 is located, the size of the pressure relief area 2133 is R2. The size R2 of the pressure relief area 2133 passes through the center of the pressure relief area 2133. Then, by setting R2 greater than R1, it can be achieved that the orthographic projection of the central through-hole 223 towards the first wall 201 is located within the orthographic projection of the pressure relief area 2133 towards the first wall 201. For example, if the pressure relief area 2133 is circular, the diameter of the pressure relief area 2133 is R2, but the embodiment of the present application is not limited thereto.

[0122] In the embodiment of the present application, the pressure relief mechanism 213 includes a protection sheet 2134. The protection sheet 2134 is used to protect the pressure relief area 2133. At least a part of the protection sheet 2134 is located in the second groove 2131, that is, the protection sheet 2134 is located on the side of the pressure relief area 2133 away from the inside of the battery cell 20, so as to protect the pressure relief area 2133 from being affected by the external environment or external components of the battery cell 20, thereby improving the service life of the pressure relief mechanism 213. Moreover, by setting at least a part of the protection sheet 2134 to be located in the second groove 2131, the space occupied by the pressure relief mechanism 213 can be saved, and thus the space utilization rate of multiple battery cells 20 in the battery 10 can be improved.

[0123] In some embodiments, the entire area of the protection sheet 2134 can be located in the second groove 2131. For example, as Figures 3 to 7 shown, the side wall of the second groove 2131 can be provided with a stepped structure to fix the protection sheet 2134 to the stepped structure, so that the surface of the protection sheet 2134 away from the inside of the battery cell 20 does not exceed the end of the side wall of the second groove 2131 away from the inside of the battery cell 20, but the embodiment of the present application is not limited thereto.

[0124] It should be understood that the size of the protection sheet 2134 in the embodiment of the present application can be set according to actual applications. For example, the sizes of all directions of the protection sheet 2134 are generally greater than or equal to the size of the pressure relief area 2133 to protect different positions of the pressure relief area 2133. The material of the protection sheet 2134 in the embodiment of the present application can be flexibly selected according to actual applications. For example, the material of the protection sheet 2134 can include polypropylene (PP) and / or polyethylene (PE) for easy processing.

[0125] In some embodiments, the protective sheet 2134 is provided with a third through hole 2135, which can be used to balance the pressure on both sides of the protective sheet 2134 and improve the service life of the pressure relief mechanism 213. It should be understood that the aperture of the third through hole 2135 can be flexibly set according to actual applications. For example, the aperture of the third through hole 2135 can be set according to the size R2 of the pressure relief area 2133; for example, the aperture of the third through hole 2135 can be set to be 10% to 20% of the size R2 of the pressure relief area 2133, but the embodiments of the present application are not limited thereto.

[0126] In the embodiments of the present application, the electrode terminal 214 is provided with a first through hole 2143, and the first through hole 2143 penetrates the bottom wall 2142 of the first groove 2141. In this way, when the battery cell 20 undergoes thermal runaway, the emissions inside the battery cell 20 can quickly pass through the electrode terminal 214 and act on the pressure relief mechanism 213, so that the pressure relief mechanism 213 can be actuated in time, and then the gas inside the battery cell 20 can be quickly discharged and the temperature inside the battery cell 20 can be reduced, reducing the risk of thermal diffusion and improving the reliability of the battery cell 20 and the battery 10. Moreover, when the pressure relief mechanism 213 is used to seal the first groove 2141, it can also be used to seal the first through hole 2143.

[0127] In some embodiments, as Figures 4 to 7 shown, if the first through hole 2143 is the liquid injection hole 215 of the battery cell 20, there is no need to additionally provide a liquid injection hole 215 at other positions on the first wall 201, saving space, improving the integration of the first wall 201, and further improving the space utilization rate of the battery cell 20, which is convenient for assembly and processing. In contrast Figure 3 shown, the liquid injection hole 215 of the battery cell 20 can also be provided at other positions to reduce the influence of the liquid injection hole 215 on the electrode terminal 214 and the pressure relief mechanism 213, but the embodiments of the present application are not limited thereto.

[0128] For the convenience of description, the embodiments of the present application mainly describe the case where the first through hole 2143 is the liquid injection hole 215.

[0129] In some embodiments, the central axis of the first through hole 2143 passes through the center of the pressure relief mechanism 213, so that at least a part of the area of the first through hole 2143 is disposed opposite to the pressure relief mechanism 213, improving the actuation efficiency of the pressure relief mechanism 213 when the battery cell 20 undergoes thermal runaway, quickly discharging the gas inside the battery cell 20 and reducing the temperature inside the battery cell 20, reducing the risk of thermal diffusion, and improving the reliability of the battery cell 20 and the battery 10. Among them, the direction of the central axis of the first through hole 2143 in the embodiments of the present application is consistent with the direction of the axis L of the electrode assembly 22.

[0130] Further, the central axis of the first through hole 2143 can be set to coincide with the axis L of the electrode assembly 22, so as to further reduce the influence of the tab 222 of the electrode assembly 22 on the first through hole 2143 and the pressure relief mechanism 213. For example, when the first through hole 2143 is the liquid injection hole 215, the splashing of the electrolyte after passing through the first through hole 2143 at the flattened area of the tab 222 can also be reduced, improving the liquid injection efficiency and the reliability of the battery cell 20 and the battery 10.

[0131] In some embodiments, as Figures 3 to 7 shown, the aperture of the first through hole 2143 is R3, and the size of the aperture R3 of the first through hole 2143 can be set according to actual applications. For example, the center of the electrode assembly 22 has a central through hole 223, and the aperture R3 of the first through hole 2143 is less than or equal to the aperture R1 of the central through hole 223. On the one hand, since the aperture R3 of the first through hole 2143 is small, the area of the bottom wall 2142 of the first groove 2141 other than the first through hole 2143 is relatively large, and part of the pressure relief mechanism 213 can be blocked by this part of the area to protect the pressure relief mechanism 213 from the influence of the internal part of the battery cell 20; on the other hand, when the first through hole 2143 is the liquid injection hole 215, setting the aperture R3 of the first through hole 2143 to be small can make the electrolyte more concentrated and injected into the electrode assembly 22 after passing through the first through hole 2143, reducing splashing and improving the liquid injection efficiency.

[0132] Figure 8 shows a schematic diagram of a partial structure of the battery cell 20 according to an embodiment of the present application. For example, the Figure 8 can be as Figures 4 to 7 shown in the schematic diagram of the partial structure of the battery cell 20. Figure 9 shows an exploded schematic diagram of a partial structure of the battery cell 20 according to an embodiment of the present application. For example, the Figure 9 can be an exploded schematic diagram of a partial structure of the battery cell 20 as Figure 8 shown.

[0133] In the embodiments of the present application, as Figures 6 to 9As shown, the battery cell 20 further includes: a connection member 23 for electrically connecting to the electrode terminal 214 and the tab 222 of the electrode assembly 22 respectively. The connection member 23 is provided with a second through hole 2301. In the axial direction X of the first through hole 2143, the orthographic projection of the second through hole 2301 at least partially overlaps with the orthographic projection of the first through hole 2143. Therefore, when thermal runaway occurs in the battery cell 20, the emissions inside the battery cell 20 can quickly pass through the connection member 23 through the second through hole 2301, and then pass through the electrode terminal 214 through the first through hole 2143 and act on the pressure relief mechanism 213, so that the pressure relief mechanism 213 can be actuated in time, thereby quickly discharging the gas inside the battery cell 20 and reducing the temperature inside the battery cell 20, reducing the risk of thermal diffusion, and improving the reliability of the battery cell 20 and the battery 10. And, when the first through hole 2143 is used as the liquid injection hole 215, under the action of gravity, at least part of the injected electrolyte can directly pass through the first through hole 2143 and the second through hole 2301 in sequence and enter the battery cell 20, avoiding excessive electrolyte flowing to other positions of the connection member 23, which is more conducive to improving the liquid injection efficiency.

[0134] It should be understood that when the battery cell 20 is assembled, the connection between the electrode assembly 22 and the electrode terminal 214 on the first wall 201 is generally achieved through the connection member 23, that is, the connection member 23 needs to be electrically connected to the electrode assembly 22 and the electrode terminal 214 respectively. Specifically, the connection member 23 can be used to realize the connection between the tab 222 of the electrode assembly 22 and the electrode terminal 214. For example, the battery cell 20 can include a positive electrode terminal and a negative electrode terminal. The positive electrode terminal is electrically connected to the positive tab through a connection member 23, and the negative electrode terminal is electrically connected to the negative tab through a connection member 23. The embodiments of the present application are not limited to this.

[0135] In some embodiments, the direction of the central axis of the second through hole 2301 is the same as the direction of the central axis of the first through hole 2143.

[0136] In some embodiments, the central axis of the second through hole 2301 coincides with the central axis of the first through hole 2143. In this way, there is no offset between the first through hole 2143 and the second through hole 2301 along the axial direction of the first through hole 2143. On the one hand, when thermal runaway occurs in the battery cell 20, the emissions can pass through the connection member 23 and the electrode terminal 214 more quickly. On the other hand, it can also make the electrolyte pass through the first through hole 2143 and the second through hole 2301 more and faster and enter the battery cell 20, avoiding excessive electrolyte splashing to other positions, and further improving the liquid injection rate.

[0137] It should be understood that the size of the second through hole 2301 in the embodiments of the present application can be flexibly set according to actual applications. For example, as Figures 6 to 9 shown, if the connecting member 23 is a multi-layer structure along the central axis direction X of the second through hole 2301, then at different positions of the connecting member 23, the aperture of the second through hole 2301 can be different. For another example, the aperture of the second through hole 2301 can be set according to the aperture R3 of the first through hole 2143.

[0138] In some embodiments, the minimum aperture R4 of the second through hole 2301 is greater than or equal to the aperture R3 of the first through hole 2143, so as to reduce the blockage of the electrolyte flowing through the first through hole 2143 by different regions of the second through hole 2301, accelerate the speed of the electrolyte flowing into the battery cell 20 and wetting the electrode assembly 22, and improve the liquid injection efficiency.

[0139] It should be understood that the specific structure of the connecting member 23 in the embodiments of the present application can be flexibly set according to actual applications. For example, Figure 10 shows a schematic structural diagram of the connecting member 23 in the embodiments of the present application. For example, the Figure 10 shown connecting member 23 can be Figure 8 and Figure 9 shown connecting member 23, wherein, Figure 10 is a schematic structural diagram of the connecting member 23 in the fully unfolded state, Figure 9 is a schematic structural diagram of the connecting member 23 in the bent state, Figure 8 is a schematic structural diagram of the connecting member 23 in the partially bent state.

[0140] As Figures 8 to 10 shown, the connecting member 23 in the embodiments of the present application includes a first part 231, a second part 232, and a third part 233 stacked along the central axis direction X of the first through hole 2143. The first part 231 and the second part 232 are connected by a first bending part 234, the second part 232 and the third part 233 are connected by a second bending part 235, the first part 231 is electrically connected to the electrode terminal 214, and the third part 233 is electrically connected to the tab 222. If the connecting member 23 is set as a folding structure, then when the connecting member 23 is in the unfolded state as Figure 10 shown, its surface area is larger. When the connecting member 23 is in the state as Figure 9The area occupied in the folded state can be relatively small. In this way, when assembling the battery cell 20, the first part 231 can be electrically connected to the electrode terminal 214 provided on the cover plate 212 first while the connecting member 23 is not folded, then the third part 233 is electrically connected to the tab 222, and finally the connecting member 23 is folded to complete the assembly. Since the surface area of the connecting member 23 is relatively large when unfolded, when the third part 233 is electrically connected to the tab 222, the first part 231 is far from the third part 233, and it is not easy to affect the electrode terminal 214 and the cover plate 212. Moreover, by folding the connecting member 23, the space occupied by the connecting member 23 in the battery cell 20 can be reduced.

[0141] In some embodiments, as Figures 8 to 10 shown, the first bending portion 234 and the second bending portion 235 are respectively located at opposite ends of the second part 232. In this way, for the unfolded connecting member 23, the first part 231, the first bending portion 234, the second part 232, the second bending portion 235, and the third part 233 are sequentially distributed along the length direction of the connecting member 23, which can increase the length of the connecting member 23. When the third part 233 is electrically connected to the tab 222, the distance between the first part 231 and the third part 233 is relatively far. For example, there is at least the second part 232 between the first part 231 and the third part 233, so that the electrode terminal 214 and the cover plate 212 are far away and are not likely to be affected. Moreover, by folding the connecting member 23, the space occupied by the connecting member 23 in the battery cell 20 can also be reduced.

[0142] As Figures 8 to 10 shown, the second through hole 2301 penetrates at least the first part 231 and the second part 232, which can reduce the blockage of the first part 231 and the second part 232 to the electrolyte and accelerate the speed of the electrolyte flowing into the battery cell 20 and wetting the electrode assembly 22.

[0143] Exemplarily, as Figures 8 to 10 shown, the first part 231 includes a first hole 2311, the second part 232 includes a second hole 2321, and the second through hole 2301 includes the first hole 2311 and the second hole 2321, that is, the second through hole 2301 penetrates the first part 231 and the second part 232. Further, the aperture of the first hole 2311 and the aperture of the second hole 2321 can be set to be both larger than the aperture R3 of the liquid injection hole 215. By setting the aperture of the first hole 2311 and the aperture of the second hole 2321 to be both larger than the aperture R3 of the liquid injection hole 215, the blockage of the first hole 2311 and the second hole 2321 to the electrolyte flowing in through the liquid injection hole 215 can be reduced, and the speed of the electrolyte flowing into the battery cell 20 and wetting the electrode assembly 22 can be accelerated.

[0144] As Figures 8 to 10 shown, the second through-hole 2301 may also penetrate the third part 233, that is, the second through-hole 2301 may sequentially penetrate the first part 231, the second part 232, and the third part 233. When the second through-hole 2301 penetrates the first part 231, the second part 232, and the third part 233, when the battery cell 20 is thermally out of control, the emissions can quickly pass through the multi-layer structure of the connection member 23; and, when the first through-hole 2143 is the liquid injection hole 215, the electrolyte flowing into the battery cell 20 through the liquid injection hole 215 can quickly reach the electrode assembly 22 through the second through-hole 2301, thereby accelerating the infiltration speed and improving the infiltration efficiency.

[0145] Exemplarily, the third part 233 includes a third hole 2331, the second through-hole 2301 includes the third hole 2331, and the aperture of the third hole 2331 is also larger than the aperture R3 of the liquid injection hole 215. By setting the aperture of the third hole 2331 to be larger than the aperture of the liquid injection hole 215, the blockage of the third hole 2331 to the electrolyte can be reduced, and the speed of the electrolyte flowing into the battery cell 20 and infiltrating the electrode assembly 22 can be accelerated.

[0146] It should be understood that the specific values of the aperture of the first hole 2311, the aperture of the second hole 2321, and the aperture of the third hole 2331 can be flexibly set according to actual applications. For example, the aperture of the first hole 2311, the aperture of the second hole 2321, and the aperture of the third hole 2331 can be set to decrease in sequence. On the one hand, the electrolyte can be converged, and on the other hand, when the liquid injection rate requirement of the electrolyte is met, that is, when the electrolyte flowing into the battery cell 20 through the liquid injection hole 215 is not blocked, the aperture of the third hole 2331 is set to be smaller so that the area of other regions of the third part 233 for electrically connecting with the tab 222 is larger, so as to improve the structural stability of the electrical connection between the third part 233 and the tab 222.

[0147] It should be understood that when folding the connection member 23, the central axes of the first hole 2311, the central axis of the second hole 2321, and the central axis of the third hole 2331 can be made to coincide with each other so that the three holes are aligned. For example, as Figures 8 to 10 shown, taking the aperture of the first hole 2311, the aperture of the second hole 2321, and the aperture of the third hole 2331 decreasing in sequence as an example, when the three holes are aligned, the three holes will not relatively block each other, meeting the liquid injection rate and ensuring the liquid injection efficiency.

[0148] In the embodiment of the present application, the battery cell 20 further includes: a sealing structure 216, at least a part of the sealing structure 216 is located in the first through hole 2143 to seal the first through hole 2143. By sealing the first through hole 2143 with the sealing structure 216, the overflow of the internal electrolyte can be reduced, and the corrosion of the pressure relief mechanism 213 by the electrolyte can be reduced. For example, the corrosion of the pressure relief area 2133 can be reduced, and the service life of the pressure relief mechanism 213 can be improved. In addition, when the battery cell 20 undergoes thermal runaway, the sealing structure 216 can leave the first through hole 2143 so that the gas inside the battery cell 20 can be quickly discharged, the temperature of the battery cell 20 can be reduced, the risk of thermal diffusion can be reduced, and the reliability of the battery cell 20 and the battery 10 can be improved.

[0149] It should be understood that the sealing structure 216 in the embodiment of the present application can be implemented in various ways. For example, the sealing structure 216 can be a sealing nail. Exemplarily, the sealing nail can be disposed in the first through hole 2143 and flush with other areas of the bottom wall 2142 of the first groove 2141 to reduce the wear of the pressure relief mechanism 213 when the sealing nail protrudes from the bottom wall 2142 of the first groove 2141 and improve the service life of the pressure relief mechanism 213. Further, at least a part of the sealing structure 216 can also extend into the second through hole 2301 to facilitate assembly.

[0150] In the embodiment of the present application, the battery cell 20 of the embodiment of the present application further includes other components.

[0151] It should be understood that the electrode terminal 214 in the embodiment of the present application can be disposed on the first wall 201 in various ways. For example, the first wall 201 can be provided with an electrode lead-out hole 2121, and the electrode terminal 214 passes through the electrode lead-out hole 2121 and is riveted to the first wall 201. Further, a first insulating structure 217 is further disposed between the electrode terminal 214 and the first wall 201 to electrically insulate the electrode terminal 214 from the first wall 201. Further, the first insulating structure 217 can be provided with a first electrode hole 2171 to enable the electrode terminal 214 to pass through the corresponding first electrode hole 2171 and be fixed by riveting. Wherein, at least a part of the first insulating structure 217 is located in the electrode lead-out hole 2121 of the first wall 201 so that electrical insulation can be achieved between the electrode terminal 214 and the inner wall of the electrode lead-out hole 2121 through the first insulating structure 217.

[0152] In some embodiments, a second insulating structure 218 may be further provided on the side of the first wall 201 facing the electrode assembly 22. On the one hand, the second insulating structure 218 can electrically insulate the electrode terminal 214 from the first wall 201. On the other hand, the second insulating structure 218 can also be used to support the first wall 201, for example, to support the cover plate 212 to improve the structural stability of the cover plate 212. Further, the second insulating structure 218 may be provided with a second electrode hole 2181 to allow the electrode terminal 214 to pass through the second electrode hole 2181 and be fixed to the first wall 201 by riveting. For example, the electrode terminal 214 can pass through the second electrode hole 2181 such that a partial area of the second insulating structure 218 is located between the electrode terminal 214 and the surface of the first wall 201 facing the electrode assembly 22.

[0153] It should be understood that the electrode terminal 214 of the embodiment of the present application is used to output the electric energy of the battery cell 20. For example, the busbar component 12 of the battery 10 can be used to electrically connect the electrode terminals 214 of multiple battery cells 20 to output the electric energy of the multiple battery cells 20. Therefore, the electrode terminal 214 is provided with a first welding area 2144 to achieve the welding between the electrode terminal 214 and the busbar component 12.

[0154] In some embodiments, a first welding area 2144 is provided on the side of the electrode terminal 214 away from the inside of the battery cell. The first welding area 2144 is located around the area where the pressure relief mechanism 213 is located. The first welding area 2144 is used to be electrically connected to the busbar component 12. By arranging the first welding area 2144 around the pressure relief mechanism 213 and avoiding at least a partial area of the pressure relief mechanism 213, when welding the electrode terminal 214 and the busbar component 12, the influence of the welding on the pressure relief mechanism 213 can be reduced, the structural stability of the pressure relief mechanism 213 can be improved, and further the stability of the battery cell 20 can be improved.

[0155] In some embodiments, a protection piece 2134 is provided on the side of the pressure relief mechanism 213 close to the first welding area 2144, and the first welding area 2144 can avoid the protection piece 2134; further, the first welding area 2144 can also avoid the side of the second groove 2131 of the pressure relief mechanism 213 away from the inside of the battery cell 20 to minimize the influence of the welding process on the pressure relief mechanism 213.

[0156] Figure 11 Shows a connection schematic diagram of any two battery cells 20 in the battery 10 of the embodiment of the present application. For example, the Figure 11 can be as Figure 2 shown in the partial structural schematic diagram of the battery 10, and can be Figure 2Any two electrically connected battery cells 20 included in the battery 10 shown; Figure 12 The possible structural schematic diagram of the busbar component 12 according to the embodiment of the present application is shown. As Figure 11 and Figure 12 shown, the battery 10 according to the embodiment of the present application further includes: a busbar component 12, and the busbar component 12 is used for electrically connecting the electrode terminals 214 of a plurality of battery cells 20. Specifically, the battery cells 20 in the battery 10 may include at least two electrode terminals 214, and the at least two electrode terminals 214 may include at least one first electrode terminal 214a and at least one second electrode terminal 214b, wherein the first electrode terminal 214a and the second electrode terminal 214b have opposite polarities. The busbar component 12 is used for electrically connecting the first electrode terminal 214a of one battery cell 20 to the second electrode terminal 214b of another battery cell 20.

[0157] For the convenience of description, in the embodiment of the present application, it is mainly taken as an example that the structures of each battery cell 20 included in the battery 10 are the same, and each battery cell 20 is only provided with one pressure relief mechanism 213. Specifically, as Figure 11 and Figure 12 shown, each battery cell 20 includes a first wall 201, the first wall 201 is provided with a first electrode terminal 214a, and the first electrode terminal 214a is provided with a pressure relief mechanism 213; in addition, the other wall of each battery cell 20 opposite to the first wall 201 is provided with a second electrode terminal 214b, and the second electrode terminal 214b is not provided with a pressure relief mechanism 213. Wherein, the first electrode terminal 214a and the second electrode terminal 214b have opposite polarities. For example, if the first electrode terminal 21a is a positive electrode terminal, then the second electrode terminal 214b is a negative electrode terminal; if the first electrode terminal 21a is a negative electrode terminal, then the second electrode terminal 214b is a positive electrode terminal.

[0158] In some embodiments, for the first electrode terminal 214a provided with a pressure relief mechanism 213, a first welding area 2144 is provided on the side of the first electrode terminal 214a away from the inside of the battery cell, and the first welding area 2144 is located around the area where the pressure relief mechanism 213 is located.

[0159] Correspondingly, the busbar component 12 includes an avoidance opening 121 and a second welding area 122. The second welding area 122 is located around the avoidance opening 121, and the second welding area 122 is used for electrically connecting to the electrode terminal 214. The avoidance opening 121 is used for avoiding at least part of the area of the pressure relief mechanism 213. The electrical connection between the busbar component 12 and the electrode terminal 214 can be realized through the second welding area 122, and the influence of welding on the pressure relief mechanism 213 can be reduced through the avoidance opening 121.

[0160] For example, as Figures 11 to 12 shown, a pressure relief mechanism 213 is provided on the first electrode terminal 214a, and the first welding area 2144 of the first electrode terminal 214a is located around the area where the pressure relief mechanism 213 is located. The avoidance opening 121 included in the bus bar component 12 is used to avoid at least part of the area of the pressure relief mechanism 213, and the second welding area 122 is used to achieve electrical connection with the first welding area 2144 of the first electrode terminal 214a.

[0161] In some embodiments, a protection sheet 2134 is provided on the pressure relief mechanism 213, and the avoidance opening 121 is used to avoid the protection sheet 2134. The protection sheet 2134 in the embodiments of the present application can be used to protect the pressure relief area 2133 of the pressure relief mechanism 213. The avoidance opening 121 at least avoids the area where the protection sheet 2134 is located, which can reduce the damage to the protection sheet 2134, so that the protection sheet 2134 can protect the pressure relief area 2133 to improve the service life of the pressure relief mechanism 213. For example, if the avoidance opening 121 is circular, the aperture R5 of the avoidance opening 121 should be at least greater than or equal to the size of the protection sheet 2134. For example, if the protection sheet 2134 is also circular, it should be at least greater than or equal to the diameter of the protection sheet 2134, but the embodiments of the present application are not limited thereto.

[0162] For the second electrode terminal 214b without the pressure relief mechanism 213, the bus bar component 12 includes a third welding area 123, and the third welding area 123 can be used to achieve electrical connection between the bus bar component 12 and the side of the second electrode terminal 214b away from the inside of the battery cell 20.

[0163] In some embodiments, if the second electrode terminal 214b of the battery cell 20 is also provided with the pressure relief mechanism 213, when the bus bar component 12 connects two electrode terminals 214 both provided with the pressure relief mechanism 213, the bus bar component 12 correspondingly includes two avoidance openings 121 to respectively avoid the pressure relief mechanisms 213 of different battery cells 20; on the contrary, if neither of the two electrode terminals 214 of the battery cell 20 is provided with the pressure relief mechanism 213, the bus bar component 12 may not be provided with the avoidance opening 121 to improve the connection efficiency.

[0164] According to some embodiments of the present application, the present application also provides an electrical device, including the battery described in any of the above solutions, and the battery is used to provide electrical energy for the electrical device.

[0165] The electrical device may be any of the foregoing devices or systems using the battery.

[0166] According to some embodiments of the present application, refer to Figures 4 to 6, the present application provides a battery cell. The battery cell 20 includes: a first wall 201 provided with a pressure relief mechanism 213; an electrode assembly 22 which is cylindrical, and the projection of the axis of the electrode assembly 22 on the first wall 201 is located within the area where the pressure relief mechanism 213 of the first wall 201 is located. The axis of the electrode assembly 22 passes through the center of the pressure relief mechanism 213. The battery cell further includes: an electrode terminal 214 provided on the first wall 201, and the pressure relief mechanism 213 is provided on the electrode terminal 214. The central axis of the electrode terminal 214 passes through the center of the pressure relief mechanism 213. The electrode terminal 214 is provided with a first groove 2141 with an opening facing the outside of the battery cell, at least part of the pressure relief mechanism 213 is located within the first groove 2141, and the pressure relief mechanism 213 is used to seal the opening of the first groove 2141. The electrode terminal 214 is provided with a first through hole 2143 that penetrates the bottom wall 2142 of the first groove 2141. The battery cell further includes: a connection member 23 for electrically connecting to the electrode tab 222 of the electrode terminal 214 and the electrode assembly 22 respectively. The connection member 23 is provided with a second through hole 2301. In the axial direction of the first through hole 2143, the projection of the second through hole 2301 at least partially overlaps with the projection of the first through hole 2143. The first through hole 2143 is the liquid injection hole 215 of the battery cell. On the side of the electrode terminal 214 away from the inside of the battery cell, there is a first welding area 2144 located around the area where the pressure relief mechanism 213 is located, and the first welding area 2144 is used to electrically connect to the bus bar component 12.

[0167] The battery 10 according to the embodiment of the present application further includes: a bus bar component 12 for electrically connecting the electrode terminals 214 of multiple battery cells. The bus bar component 12 includes an avoidance opening 121 and a second welding area 122. The second welding area 122 is located around the avoidance opening 121, and the second welding area 122 is used to electrically connect to the electrode terminal 214. The avoidance opening 121 is used to avoid at least part of the area of the pressure relief mechanism 213.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, Comprising: A first wall (201), the first wall (201) being provided with a pressure relief mechanism (213); An electrode assembly (22), the electrode assembly (22) being cylindrical, and the projection of the axis of the electrode assembly (22) onto the first wall (201) being located within the area of the first wall (201) where the pressure relief mechanism (213) is located.

2. The battery cell according to claim 1, wherein, The axis of the electrode assembly (22) passes through the center of the pressure relief mechanism (213).

3. The battery cell according to claim 1 or 2, characterized in that, The pressure relief mechanism (213) is located in the central area of the first wall (201).

4. The battery cell according to any one of claims 1 to 3, characterized in that The battery cell further comprises: An electrode terminal (214), the electrode terminal (214) being disposed on the first wall (201), and the electrode terminal (214) being provided with the pressure relief mechanism (213).

5. The battery cell according to claim 4, characterized in that, The central axis of the electrode terminal (214) passes through the center of the pressure relief mechanism (213).

6. The battery cell according to claim 4 or 5, characterized in that, The electrode terminal (214) is provided with a first groove (2141) having an opening facing the outside of the battery cell, at least a part of the pressure relief mechanism (213) being located within the first groove (2141), and the pressure relief mechanism (213) being used to seal the opening of the first groove (2141).

7. The battery cell according to claim 6, wherein, The pressure relief mechanism (213) includes a second groove (2131) having an opening facing the outside of the battery cell, and a pressure relief area (2133) being provided on the bottom wall (2132) of the second groove (2131).

8. The battery cell according to claim 7, characterized in that, The center of the electrode assembly (22) has a central through hole (223), and the projection of the central through hole (223) onto the first wall (201) is located within the projection of the pressure relief area (2133) onto the first wall (201).

9. The battery cell according to claim 7 or 8, characterized in that, The pressure relief mechanism (213) includes a protective sheet (2134), the protective sheet (2134) being used to protect the pressure relief area (2133), and at least a part of the protective sheet (2134) being located within the second groove (2131).

10. The battery cell according to claim 9, wherein, The protective sheet (2134) is provided with a third through hole (2135).

11. The battery cell according to any one of claims 6 to 10, characterized in that, The electrode terminal (214) is provided with a first through hole (2143), and the first through hole (2143) penetrates the bottom wall (2142) of the first groove (2141).

12. The battery cell according to claim 11, wherein, The central axis of the first through hole (2143) passes through the center of the pressure relief mechanism (213).

13. The battery cell according to claim 11 or 12, characterized in that, The center of the electrode assembly (22) has a central through hole (223), and the diameter of the first through hole (2143) is less than or equal to the diameter of the central through hole (223).

14. The battery cell according to any one of claims 11 to 13, characterized in that, The battery cell further comprises: A connecting member (23) for electrically connecting to the electrode terminal (214) and the tab (222) of the electrode assembly (22) respectively, the connecting member (23) being provided with a second through hole (2301), In the direction of the central axis of the first through hole (2143), the projection of the second through hole (2301) overlaps at least partially with the projection of the first through hole (2143).

15. The battery cell according to claim 14, characterized in that, The central axis of the second through hole (2301) coincides with the central axis of the first through hole (2143).

16. The battery cell according to any one of claims 11 to 15, characterized in that, The battery cell further comprises: A sealing structure (216), at least a partial area of the sealing structure (216) is located within the first through hole (2143) to seal the first through hole (2143).

17. The battery cell according to any one of claims 11 to 16, characterized in that, The first through hole (2143) is the liquid injection hole (215) of the battery cell.

18. The battery cell according to any one of claims 4 to 17, characterized in that, On a side of the electrode terminal (214) away from the interior of the battery cell, a first welding area (2144) is provided. The first welding area (2144) is located around the area where the pressure relief mechanism (213) is located. The first welding area (2144) is used for electrical connection with the busbar component (12).

19. The battery cell according to any one of claims 1 to 18, characterized in that, The battery cell includes: A housing (211), the housing (211) being a hollow structure with an opening (2111); A cover plate (212) for covering the opening (2111) of the housing (211). The first wall (201) is the cover plate (212).

20. The battery cell according to any one of claims 1 to 19, characterized in that, The first wall (201) is circular or rectangular.

21. A battery, characterized in that, Including: The battery cell according to any one of claims 1 to 20.

22. The battery according to claim 21, wherein The battery cell includes an electrode terminal (214). The electrode terminal (214) is disposed on the first wall (201). The electrode terminal (214) is provided with the pressure relief mechanism (213). The battery further includes: A busbar component (12), the busbar component (12) being used for electrically connecting the electrode terminals (214) of multiple battery cells. The busbar component (12) includes an avoidance opening (121) and a second welding area (122). The second welding area (122) is located around the avoidance opening (121). The second welding area (122) is used for electrical connection with the electrode terminal (214). The avoidance opening (121) is used for avoiding at least a partial area of the pressure relief mechanism (213).

23. The battery according to claim 22, characterized in that, The pressure relief mechanism (213) is provided with a protection sheet (2134). The avoidance opening (121) is used for avoiding the protection sheet (2134).

24. An electrical device, characterized in that, Including: A battery, the battery including multiple battery cells according to any one of claims 1 to 20. The battery is used for providing electrical energy to the electrical device.

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