Battery monomer, shell assembly, battery and electric device

Abstract

The utility model provides a battery monomer, a shell assembly, a battery and an electric device. A battery cell includes: a case assembly including a chamber having at least one end open in a first direction; the top cover assembly covers the opening; the electrode assembly is arranged in the cavity; wherein at least one of the shell assembly and the top cover assembly is provided with a pressure relief mechanism, the pressure relief mechanism is configured to be actuated to relieve the pressure in the cavity when the pressure in the cavity reaches a threshold value, a pressure relief groove is formed in the surface of the side, facing the cavity, of the shell assembly or the top cover assembly, and the pressure relief groove communicates with the pressure relief mechanism and the cavity.

Description

Technical Field

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

[0002] Batteries are widely used in electronic devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc.

[0003] In battery production, a pressure relief mechanism is usually provided in the battery cell. When the battery cell undergoes thermal runaway, the pressure relief mechanism can relieve pressure. And in order to ensure the reliability of the pressure relief mechanism, a spacer is usually provided in the battery housing to isolate the electrode assembly and the pressure relief mechanism. The spacer needs to occupy additional internal space of the housing, resulting in a decrease in the energy density of the battery cell. Summary of the Utility Model

[0004] In view of the above problems, the present application provides a battery cell, a housing assembly, a battery, and an electrical device, which can improve the utilization rate of the internal space of the housing assembly and increase the energy density of the battery cell.

[0005] In a first aspect, the present application provides a battery cell, including: a housing assembly including a chamber having at least one end open in a first direction; a top cover assembly covering the opening; and an electrode assembly disposed in the chamber; wherein, at least one of the housing assembly or the top cover assembly is provided with a pressure relief mechanism configured to actuate to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold, and a pressure relief groove is provided on a surface of the housing assembly or the top cover assembly facing the chamber, and the pressure relief groove communicates with the pressure relief mechanism and the chamber.

[0006] In the solution of the embodiment of the present application, the battery cell includes a housing assembly, a top cover assembly, and an electrode assembly. The housing assembly includes a chamber having at least one end open in a first direction, and the top cover assembly covers the opening; the electrode assembly is disposed in the chamber. At least one of the housing assembly or the top cover assembly is provided with a pressure relief mechanism configured to actuate to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold, so as to reduce the impact on other battery cells after the battery cell undergoes thermal runaway. A pressure relief groove is provided on a surface of the housing assembly or the top cover assembly facing the chamber, and the pressure relief groove communicates with the pressure relief mechanism and the chamber. By providing a pressure relief groove on the housing assembly or the top cover assembly that communicates with the pressure relief mechanism and the chamber, when the battery undergoes thermal runaway, gas can be guided through the pressure relief groove to the pressure relief mechanism and released to the external environment, so as to improve the reliability of the pressure relief mechanism. By using the pressure relief groove to replace at least part of the exhaust space formed by the spacer, the pressure relief groove provided in the housing assembly does not need to occupy additional internal space of the housing assembly. Therefore, the utilization rate of the internal space of the housing assembly can be improved to increase the energy density of the battery cell.

[0007] In some embodiments, the housing assembly includes a bottom plate disposed opposite to the top cover assembly, a first side plate and a second side plate connected to the bottom plate. The two first side plates are disposed opposite to each other in the second direction, and the two second side plates are disposed opposite to each other in the third direction. There is a gap between the electrode assembly and the first side plate. The first direction, the second direction, and the third direction intersect, and the third direction is the thickness direction of the electrode assembly. The pressure relief groove and the pressure relief mechanism are both provided on at least one of the bottom plate, the top cover assembly, or the first side plate.

[0008] In the technical solution of the embodiment of the present application, the housing assembly includes a bottom plate disposed opposite to the top cover assembly, a first side plate and a second side plate connected to the bottom plate. The expansion amount of the battery cell in the third direction is relatively large. Therefore, the pressure relief mechanism and the pressure relief groove are provided at the first side plate, the bottom plate, or the top cover assembly to maintain the structural strength of the second side plate. When the battery cell is out of control due to heat, the electrode terminal generates more gas in the first direction. Therefore, the pressure relief mechanism and the pressure relief groove are provided at the bottom plate or the top cover assembly. The pressure relief groove can fully guide gas to the pressure relief mechanism to improve the pressure relief reliability of the pressure relief mechanism. Or when the battery is out of control due to heat, gas will accumulate in the gap between the first side plate and the electrode assembly. Therefore, the pressure relief groove and the pressure relief mechanism are provided on the same first side plate. The pressure relief groove can guide the gas in the gap to the pressure relief mechanism to improve the pressure relief reliability of the pressure relief mechanism.

[0009] In some embodiments, the pressure relief mechanism is connected to the gap and one end of the electrode assembly in the first direction through the pressure relief groove.

[0010] In these embodiments, the pressure relief mechanism can be connected to the gap and one end of the electrode assembly in the first direction through the pressure relief groove, so that when the battery cell is out of control due to heat, the pressure relief mechanism can fully release pressure to the outside to improve the reliability of the battery cell.

[0011] In some embodiments, the pressure relief mechanism is provided on the first side plate. The pressure relief groove includes a first groove and a second groove. The first groove is provided on the first side plate and is connected to the pressure relief mechanism and the gap. The second groove is provided on at least one of the bottom plate or the top cover assembly and is connected to the gap and one end of the electrode assembly facing the second groove.

[0012] In the technical solution of the embodiment of the present application, the pressure relief mechanism is provided on the first side plate. The pressure relief groove includes a first groove and a second groove. The first groove is provided on the first side plate. The first groove connects the pressure relief mechanism and the gap. The first groove is used to guide the gas in the gap to the pressure relief mechanism and release it to the outside. The second groove is provided on at least one of the bottom plate or the top cover assembly and is connected to the gap and one end of the electrode assembly facing the second groove, so that the gas released by the electrode assembly in the first direction can be transmitted to the gap through the second groove and released to the outside by the pressure relief mechanism to improve the reliability of the pressure relief mechanism and reduce the damage caused when the battery cell is out of control due to heat.

[0013] In some embodiments, the pressure relief mechanism and the pressure relief groove are both disposed on at least one of the bottom plate or the top cover assembly, and the pressure relief mechanism is connected to the gap through the pressure relief groove.

[0014] In the technical solution of the embodiment of the present application, the pressure relief mechanism and the pressure relief groove are both arranged on at least one of the bottom plate or the top cover assembly, and the pressure relief mechanism is connected to the gap through the pressure relief groove, so that when the battery cell thermally runs away, the pressure relief groove can guide the gas in the gap and the gas released from the electrode assembly toward one end of the pressure relief groove to the pressure relief mechanism, so as to improve the reliability of the pressure relief mechanism and reduce the risk of heat spread caused by thermal runaway of the battery cell.

[0015] In some embodiments, the battery cell further includes a support mechanism disposed between at least one of the bottom plate and the first side plate and the electrode assembly, the support mechanism includes a pressure relief channel connected to the pressure relief mechanism, and the support mechanism and the pressure relief groove are spaced apart.

[0016] In the technical solution of the embodiment of the present application, the battery cell also includes a supporting mechanism, which is arranged between at least one of the bottom plate and the first side plate and the electrode assembly. The supporting mechanism and the pressure relief groove cooperate to form a pressure relief space between the electrode assembly and the pressure relief mechanism. The supporting mechanism includes a pressure relief channel connected to the pressure relief mechanism to facilitate the pressure relief mechanism to release the pressure in the chamber during thermal runaway. Under the premise of ensuring the volume of the pressure relief space, the problem of the pressure relief groove being too deep causing the structural strength of the shell assembly to decrease and the support mechanism occupying too much space inside the chamber can be improved. The supporting mechanism and the pressure relief groove are arranged at intervals to improve the problem of poor airflow in the pressure relief groove due to the support mechanism blocking the pressure relief groove.

[0017] In some embodiments, the support mechanism covers a portion of the pressure relief groove, and at least one end of the pressure relief groove facing away from the pressure relief mechanism extends out of the orthographic projection area of the support mechanism in the thickness direction thereof.

[0018] In the technical solution of the embodiment of the present application, the support mechanism covers part of the pressure relief groove to reduce the difficulty of processing and assembly of the support mechanism. At least one end of the pressure relief groove that is away from the pressure relief mechanism extends out of the positive projection area of the support mechanism in its thickness direction to facilitate the gas in the chamber to enter the pressure relief groove and improve the pressure relief efficiency of the pressure relief groove.

[0019] In some embodiments, the support mechanism includes a first support portion and a second support portion, the first support portion is connected to the electrode assembly, and two or more second support portions are arranged at intervals and connected between the first support portion and the shell assembly.

[0020] In the technical solution of the embodiment of the present application, the support mechanism includes a first support portion and a second support portion. The first support portion is connected to the electrode assembly. Two or more second support portions are arranged at intervals and are connected between the first support portion and the housing assembly. Moreover, the second support portion and the pressure relief groove are arranged at intervals. By means of the first support portion, the contact area between the electrode assembly and the support mechanism is increased, and the risk of the support mechanism scratching the electrode assembly is reduced. Two or more second support portions are arranged at intervals and are connected between the first support portion and the housing assembly to increase the space between the first support portion and the pressure relief groove, facilitating the airflow in the chamber to enter the pressure relief groove during thermal runaway, so as to improve the pressure relief effect of the pressure relief groove.

[0021] In some embodiments, the minimum distance L between the second support portion and the pressure relief groove is greater than or equal to 0.5 mm.

[0022] In the technical solution of the embodiment of the present application, when the minimum distance between the second support portion and the pressure relief groove meets the above range, the problem that the second support portion blocks the pressure relief groove due to the assembly error between the support mechanism and the housing assembly can be improved.

[0023] In some embodiments, the pressure relief groove includes a first segment and a second segment. Two or more first segments are arranged at intervals in the thickness direction of the electrode assembly, and the second segment communicates with each first segment.

[0024] In the technical solution of the embodiment of the present application, the pressure relief groove includes a first segment and a second segment. Two or more first segments are arranged at intervals in the thickness direction of the electrode assembly. The spaced-apart first segments help to enhance the structural strength of the housing assembly, and the second segment communicates with each first segment to increase the overall volume of the pressure relief groove and improve the overall pressure relief efficiency of the pressure relief groove.

[0025] In some embodiments, the pressure relief mechanism is a scoring groove provided in the housing assembly, and the pressure relief groove communicates with the scoring groove; or a through hole is provided in the housing assembly, the pressure relief mechanism is a cover plate covering the through hole, and the cover plate is configured to disengage from the through hole when the pressure in the chamber reaches a threshold value to release the internal pressure of the chamber, and the pressure relief groove communicates with the through hole.

[0026] In the technical solution of the embodiment of the present application, the pressure relief mechanism is a scoring groove provided in the housing assembly, and the pressure relief groove communicates with the scoring groove, so that when the battery undergoes thermal runaway, the housing assembly tears at the scoring groove, and the gas in the chamber can be released to the outside along the pressure relief groove through the tearing part of the scoring groove, so as to reduce the risk of thermal propagation caused by the thermal runaway of a single battery cell; or a through hole is provided in the housing assembly, the pressure relief mechanism is a cover plate covering the through hole, and the pressure relief groove communicates with the through hole, so that when the battery undergoes thermal runaway, the cover plate disengages from the through hole, and the gas in the chamber can be released to the outside along the pressure relief groove through the through hole, so as to reduce the risk of thermal propagation caused by the thermal runaway of a single battery cell.

[0027] In some embodiments, in the arrangement direction of the pressure relief groove and the pressure relief mechanism, the extension dimension D1 of the pressure relief groove and the dimension D2 of the housing assembly satisfy D1 ≥ 0.7 * D2.

[0028] In the technical solution of the embodiment of the present application, for the extension dimension D1 of the pressure relief groove and the dimension D2 of the housing assembly in the extension direction of the pressure relief groove, when D1 and D2 satisfy the above range, the pressure relief groove can well play the role of guiding the gas in the chamber to the pressure relief mechanism when the battery cell is thermally out of control, so as to improve the pressure relief reliability of the pressure relief mechanism.

[0029] In some embodiments, the depth L1 of the pressure relief groove and the thickness L2 of the housing assembly satisfy L2 / 3 ≤ L1 ≤ L2 / 2.

[0030] In the technical solution of the embodiment of the present application, when the depth L1 of the pressure relief groove and the thickness L2 of the housing assembly satisfy the above range, a sufficient pressure relief space can be formed in the pressure relief groove on the basis of ensuring the structural strength of the housing assembly, so as to improve the pressure relief reliability of the pressure relief mechanism.

[0031] In a second aspect, the embodiment of the present application provides a housing assembly applied to the battery cell in any embodiment of the first aspect. The housing assembly includes a chamber with at least one end open in a first direction and a pressure relief mechanism arranged on the housing assembly. The pressure relief mechanism is configured to actuate to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold. A pressure relief groove is provided on one surface of the housing assembly facing the chamber, and the pressure relief groove communicates with the pressure relief mechanism and the chamber.

[0032] In the technical solution of the embodiment of the present application, the housing assembly includes a chamber with at least one end open in a first direction and a pressure relief mechanism arranged on the housing assembly. The pressure relief mechanism is configured to actuate to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold, so as to reduce the impact on other battery cells after the battery cell is thermally out of control. A pressure relief groove is provided on one surface of the housing assembly facing the chamber. By providing a pressure relief groove on the housing assembly that communicates with the pressure relief mechanism and the chamber, when the battery is thermally out of control, the gas can be guided to the pressure relief mechanism through the pressure relief groove and released to the external environment. The pressure relief groove replaces at least part of the exhaust space formed by the spacer block to improve the reliability of the pressure relief mechanism, and the pressure relief groove provided on the housing assembly does not need to additionally occupy the internal space of the housing, thereby improving the utilization rate of the internal space of the housing assembly and enhancing the energy density of the battery cell.

[0033] In some embodiments, the pressure relief groove includes a first segment and a second segment. Two or more first segments are arranged at intervals in the thickness direction of the electrode assembly, and the second segment communicates with each first segment.

[0034] In the technical solution of the embodiment of the present application, the pressure relief groove includes a first segment and a second segment. Two or more first segments are arranged at intervals in the thickness direction of the electrode assembly. The first segments arranged at intervals help to improve the structural strength of the housing assembly. The second segment communicates with each first segment to increase the overall volume of the pressure relief groove and improve the overall pressure relief efficiency of the pressure relief groove.

[0035] In some embodiments, the pressure relief mechanism is a scoring groove provided in the housing assembly, and the pressure relief groove communicates with the scoring groove; or a through hole is provided in the housing assembly, the pressure relief mechanism is a cover plate covering the through hole, and the cover plate is configured to separate from the through hole when the pressure in the chamber reaches a threshold value to release the internal pressure of the chamber, and the pressure relief groove communicates with the through hole.

[0036] In the technical solution of the embodiment of the present application, the pressure relief mechanism is a scoring groove provided in the housing assembly, and the pressure relief groove communicates with the scoring groove, so that when the battery is in thermal runaway, the housing assembly tears at the scoring groove, and the gas in the chamber can be released to the outside along the pressure relief groove through the tearing at the scoring groove, so as to reduce the risk of thermal spread caused by the thermal runaway of the battery cell; or a through hole is provided in the housing assembly, the pressure relief mechanism is a cover plate covering the through hole, and the pressure relief groove communicates with the through hole, so that when the battery is in thermal runaway, the cover plate separates from the through hole, and the gas in the chamber can be released to the outside along the pressure relief groove through the through hole, so as to reduce the risk of thermal spread caused by the thermal runaway of the battery cell.

[0037] In a third aspect, the present application provides a battery, including the battery cell according to any one of the embodiments of the first aspect above.

[0038] In a fourth aspect, the present application provides an electrical device, including the battery according to the embodiment of the third aspect above. Description of the Drawings

[0039] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0040] Figure 1 is a schematic structural diagram of a vehicle provided by an embodiment of the present application;

[0041] Figure 2 is a schematic structural diagram of a battery provided by an embodiment of the present application;

[0042] Figure 3 is a schematic structural diagram of a battery module provided by an embodiment of the application;

[0043] Figure 4 is an exploded view of a battery cell provided by an embodiment of the present application;

[0044] Figure 5 is a schematic structural view of a battery cell provided by an embodiment of the present application;

[0045] Figure 6 is a schematic structural view of a housing assembly of a battery cell provided by an embodiment of the present application;

[0046] Figure 7 is a partial cross-sectional view at A-A in Figure 6 in an embodiment of the present application;

[0047] Figure 8 is a partial cross-sectional view at A-A in Figure 6 in another embodiment of the present application;

[0048] Figure 9 is Figure 6 a cross-sectional view at A-A in

[0049] Figure 10 is Figure 9 an enlarged schematic structural view at B in

[0050] Figure 11 is a schematic structural view of a support mechanism of a battery cell provided by an embodiment of the present application;

[0051] Figure 12 is a partial schematic structural view of a housing assembly of a battery cell provided by an embodiment of the present application;

[0052] Figure 13 is a partial schematic structural view of a housing assembly of a battery cell provided by an embodiment of the present application;

[0053] Figure 14 is a partial schematic structural view of a housing assembly of a battery cell provided by an embodiment of the present application.

[0054] Description of reference numerals:

[0055] 1, vehicle; 101, motor; 102, controller;

[0056] 2, battery; 201, battery module; 202, box body; 2021, first box body part; 2022, second box body part; 3, battery cell;

[0057] 4, housing assembly; 42, chamber; 43, pressure relief mechanism; 44, pressure relief groove; 411, bottom plate; 412, first side plate; 413, second side plate; 45, gap; 441, first groove; 442, second groove; 443, first segment; 444, second segment; 431, cover plate; 432, scoring groove; 414, through hole.

[0058] 5, electrode assembly;

[0059] 6. Top cover assembly; 61. Electrode terminal;

[0060] 7. Support mechanism; 71. Pressure relief channel; 72. First support part; 73. Second support part. Detailed implementation manner

[0061] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0062] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should be the ordinary meanings understood by those skilled in the art to which the embodiments of the present application belong.

[0063] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application.

[0064] In addition, technical terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality" is more than two, unless otherwise specifically defined.

[0065] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0066] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0067] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand for them is also constantly increasing.

[0068] In the present application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell or a magnesium-ion battery cell, etc., and the embodiments of the present application do not limit this. The battery cell may be in a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc., and the embodiments of the present application also do not limit this.

[0069] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0070] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector; the positive current collector includes a positive current collecting portion and a positive electrode tab connected to the positive current collecting portion. The positive current collecting portion is coated with the positive active material layer, and the positive electrode tab is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material layer includes a positive active material, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode plate includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector; the negative current collector includes a negative current collecting portion and a negative electrode tab connected to the negative current collecting portion. The negative current collecting portion is coated with the negative active material layer, and the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0071] In the prior art, during battery production, a pressure relief mechanism is usually provided in the battery cell. When the battery cell undergoes thermal runaway, pressure can be relieved through the pressure relief mechanism. And in order to ensure the reliability of the pressure relief mechanism, a spacer is usually provided inside the battery case to isolate the electrode assembly and the pressure relief mechanism. The spacer needs to occupy additional internal space of the case, resulting in a decrease in the energy density of the battery cell.

[0072] In the related art, when the battery cell undergoes thermal runaway, gas is released to the outside from the pressure relief mechanism, resulting in a lower pressure between the electrode assembly and the pressure relief mechanism compared to other areas of the case. The pressure in the chamber of the case assembly is uneven, causing the electrode assembly to block the pressure relief mechanism under the action of pressure, leading to an exacerbation of the thermal runaway of the battery cell. Therefore, in the related art, a spacer is provided between the electrode assembly and the pressure relief mechanism to form a fixed pressure relief space between the spacer and the pressure relief mechanism to improve the problem of the electrode assembly blocking the pressure relief mechanism. However, the spacer will occupy the internal chamber space of the case assembly, which will reduce the installation space of the electrode assembly, decrease the capacity of the battery cell, reduce the energy density of the battery cell, or require an increase in the volume of the case assembly, resulting in a decrease in the energy density of the battery cell.

[0073] Based on the above problems, the present application provides a battery cell. The battery cell includes a housing assembly, a top cover assembly, and an electrode assembly. The housing assembly includes a chamber that is open at least at one end in a first direction, and the top cover assembly covers the opening. The electrode assembly is disposed in the chamber, and at least one of the housing assembly or the top cover assembly is provided with a pressure relief mechanism. The pressure relief mechanism is configured to be actuated to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold value, so as to reduce the impact on other battery cells after the thermal runaway of the battery cell. A pressure relief groove is provided on a surface of the housing assembly or the top cover assembly facing the chamber. The pressure relief groove communicates with the pressure relief mechanism and the chamber. By providing a pressure relief groove on the housing assembly or the top cover assembly that communicates with the pressure relief mechanism and the chamber, when the battery undergoes thermal runaway, gas can be guided through the pressure relief groove to the pressure relief mechanism and released to the external environment, so as to improve the reliability of the pressure relief mechanism. The pressure relief groove replaces at least part of the exhaust space formed by the spacer block. The pressure relief groove provided in the housing assembly does not need to additionally occupy the internal space of the housing assembly. Therefore, the utilization rate of the internal space of the housing assembly can be improved, and the energy density of the battery cell can be increased.

[0074] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using the batteries.

[0075] 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 electric drill, a concrete vibrator, an electric planer, etc. The embodiments of the present application do not impose special restrictions on the above electrical devices.

[0076] It should be understood that the technical solutions described in the embodiments of the present application are not only limited to the batteries and electrical equipment described above, but also applicable to all batteries including boxes and electrical equipment using the batteries. However, for the sake of simplicity of description, the following embodiments will be described by taking an electric vehicle as an example.

[0077] Please refer to Figure 1 , Figure 1Schematic structural diagram of vehicle 1 provided by some embodiments of the present application. 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 battery 2 is disposed inside vehicle 1, and the battery can be disposed at the bottom, head, or tail of vehicle 1. The battery 2 can be used to supply power to vehicle 1. For example, the battery 2 can serve as the operating power source of vehicle 1. Vehicle 1 can also include a controller 102 and a motor 101. The controller 102 is used to control the battery to supply power to the motor 101. For example, it is used for the working power requirements during the start, navigation, and driving of vehicle 1.

[0078] In some embodiments of the present application, the battery can not only serve as the operating power source of vehicle 1, but also serve as the driving power source of vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for vehicle 1.

[0079] To meet different power usage requirements, the battery 2 can include a plurality of battery cells. A battery cell refers to the smallest unit that makes up a battery module or a battery pack. The plurality of battery cells can be connected in series and / or in parallel via electrode terminals for various applications. The battery 2 mentioned in the present application includes a battery module or a battery pack. Among them, the plurality of battery cells can be connected in series, in parallel, or in a series-parallel combination. The series-parallel combination means a combination of series and parallel connections. In the embodiments of the present application, the plurality of battery cells can directly form a battery pack, or can first form a battery module, and then the battery module forms a battery pack.

[0080] Figure 2 Schematic structural diagram of the battery 2 according to an embodiment of the present application is shown.

[0081] As Figure 2 shown, the battery includes a box body 202 and battery cells (not shown in the figure). The battery cells are accommodated in the box body 202.

[0082] The box body 202 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of a combination of simple three-dimensional structures such as a cuboid, cylinder, or sphere. The material of the box body 202 can be alloy materials such as aluminum alloy and ferroalloy, or polymer materials such as polycarbonate and polyisocyanurate foam plastic, or composite materials such as glass fiber reinforced epoxy resin.

[0083] The box body 202 is used to accommodate battery cells, and the box body 202 can have various structures. In some embodiments, the box body 202 can include a first box body part 2021 and a second box body part 2022. The first box body part 2021 and the second box body part 2022 are covered with each other, and the first box body part 2021 and the second box body part 2022 jointly define an accommodation space for accommodating the battery cells 3. The second box body part 2022 can be a hollow structure with an open end, and the first box body part 2021 is a plate-like structure. The first box body part 2021 is covered on the open side of the second box body part 2022 to form the box body 202 with an accommodation space; both the first box body part 2021 and the second box body part 2022 can also be hollow structures with an open side, and the open side of the first box body part 2021 is covered on the open side of the second box body part 2022 to form the box body 202 with an accommodation space. Of course, the first box body part 2021 and the second box body part 2022 can be of various shapes, such as a cylinder, a cuboid, etc.

[0084] To improve the sealing performance after the connection between the first box body part 2021 and the second box body part 2022, a sealing member can also be provided between the first box body part 2021 and the second box body part 2022, such as sealant, sealing ring, etc.

[0085] Assume that the first box body part 2021 is covered on the top of the second box body part 2022. The first box body part 2021 can also be called the upper box cover, and the second box body part 2022 can also be called the lower box cover.

[0086] In the battery 2, there can be one or multiple battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that there are both series and parallel connections among the multiple battery cells. The multiple battery cells can be directly connected in series, in parallel, or in a hybrid connection together, and then the whole formed by the multiple battery cells is accommodated in the box body 202; of course, it can also be that multiple battery cells are first connected in series, in parallel, or in a hybrid connection to form a battery module 201, and then multiple battery modules 201 are connected in series, in parallel, or in a hybrid connection to form a whole and are accommodated in the box body 202.

[0087] Figure 3 The structural schematic diagram of a battery module 201 according to an embodiment of the present application is shown.

[0088] In some embodiments, as Figure 2 and Figure 3 shown, there are multiple battery cells 3. The multiple battery cells 3 are first connected in series, in parallel, or in a hybrid connection to form a battery module 201. Multiple battery modules 201 are then connected in series, in parallel, or in a hybrid connection to form a whole and are accommodated in the box body 202.

[0089] Multiple battery cells 3 in the battery module 201 can be electrically connected through a busbar component to achieve parallel, series, or hybrid connection of the multiple battery cells 3 in the battery module 201.

[0090] In this application, the battery cell 3 can include a lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application do not limit this.

[0091] Figure 4 It is a schematic structural diagram of the battery cell 3 provided in some embodiments of this application. The battery cell 3 refers to the smallest unit that makes up a battery. For example Figure 4 , the battery cell 3 includes a top cover assembly 6, a housing assembly 4, and an electrode assembly 5.

[0092] The electrode assembly 5 is a component in the battery cell 3 where an electrochemical reaction occurs. The housing assembly 4 can contain one or more electrode assemblies 5. The electrode assembly 5 is mainly formed by winding or stacking electrode sheets. The electrode sheets are divided into positive electrode sheets and negative electrode sheets, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the electrode body, and the parts of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab can be located at one end of the electrode body part together or at both ends of the electrode body part respectively. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the electrode tabs are connected to the electrode terminal 61 to form a current loop.

[0093] The housing assembly 4 is a component used to cooperate with the top cover assembly 6 to form the internal environment of the battery cell 3. Among them, the formed internal environment can be used to accommodate the electrode assembly 5, the electrolyte (not shown in the figure), and other components. The housing assembly 4 and the top cover assembly 6 can be independent components. An opening can be provided on the housing assembly 4, and the top cover assembly 6 is covered at the opening to form the internal environment of the battery cell 3. Optionally, the top cover assembly 6 and the housing assembly 4 can also be integrated. Optionally, the top cover assembly 6 and the housing assembly 4 can form a common connection surface before other components are put into the housing, and when it is necessary to encapsulate the inside of the housing assembly 4, then the top cover assembly 6 is covered on the housing assembly 4. The housing assembly 4 can be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. The shape of the housing assembly 4 can be determined according to the specific shape and size of the electrode assembly 5. The material of the housing assembly 4 can be various. Optionally, the material of the housing assembly 4 is copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0094] In some embodiments, such as Figure 4As shown in the figure, two electrode terminals 61 can be provided in the top cover assembly 6. One electrode terminal 61 of the top cover assembly 6 is electrically connected to one tab (such as the positive tab) of the electrode assembly 5. The other electrode terminal 61 in the top cover assembly 6 is electrically connected to the other tab (such as the negative tab) of the electrode assembly 5.

[0095] Please refer to Figure 4 、 Figure 5 and Figure 6 , Figure 4 is an exploded view of a battery cell provided in an embodiment of the present application; Figure 5 is a schematic structural diagram of a housing assembly of a battery cell provided in an embodiment of the present application, Figure 6 is a schematic structural diagram of a battery cell provided in an embodiment of the present application.

[0096] In a first aspect, as Figures 4 to 6 shown, the present application provides a battery cell 3, which includes a housing assembly 4, a top cover assembly 6 and an electrode assembly 5. The housing assembly 4 includes a chamber 42 that is at least open at one end in the first direction X; the top cover assembly 6 covers the opening; the electrode assembly 5 is disposed in the chamber 42; wherein, at least one of the housing assembly 4 or the top cover assembly 6 is provided with a pressure relief mechanism 43, and the pressure relief mechanism 43 is configured to actuate to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold. A pressure relief groove 44 is provided on a surface of the housing assembly 4 or the top cover assembly 6 facing the chamber 42, and the pressure relief groove 44 communicates with the pressure relief mechanism 43 and the chamber 42.

[0097] In the solution of the embodiment of the present application, the battery cell 3 includes a housing assembly 4, a top cover assembly 6 and an electrode assembly 5. The housing assembly 4 includes a chamber 42 that is at least open at one end in the first direction X, and the top cover assembly 6 covers the opening; the electrode assembly 5 is disposed in the chamber 42. At least one of the housing assembly 4 or the top cover assembly 6 is provided with a pressure relief mechanism 43, and the pressure relief mechanism 43 is configured to actuate to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold, so as to reduce the impact on other battery cells 3 after the thermal runaway of the battery cell 3. A pressure relief groove 44 is provided on a surface of the housing assembly 4 or the top cover assembly 6 facing the chamber 42, and the pressure relief groove 44 communicates with the pressure relief mechanism 43 and the chamber 42. By providing a pressure relief groove 44 that communicates with the pressure relief mechanism 43 and the chamber 42 on the housing assembly or the top cover assembly, when the battery 2 is in thermal runaway, the gas can be guided to the pressure relief mechanism 43 through the pressure relief groove 44 and released to the external environment, so as to improve the reliability of the pressure relief mechanism 43. The pressure relief groove 44 is used to replace at least part of the exhaust space formed by the spacer block, and the pressure relief groove 44 provided in the housing assembly 4 does not need to additionally occupy the internal space of the housing assembly 4. Therefore, the utilization rate of the internal space of the housing assembly 4 can be improved to increase the energy density of the battery cell 3.

[0098] When the battery cell 3 undergoes thermal runaway, the gas in the chamber 42 increases and the air pressure rises. When the pressure in the chamber 42 reaches the threshold value, the pressure relief mechanism 43 is activated to connect the chamber 42 and the external space, and the pressure in the chamber 42 drops, so as to reduce the damage caused to the adjacent battery cells 3 after the thermal runaway of the battery cell 3. Exemplarily, the pressure relief mechanism 43 can be a scoring groove 432 provided on the housing assembly 4 or the top cover assembly 6. When the internal pressure of the chamber 42 reaches the threshold value, the housing assembly 4 or the top cover assembly 6 tears at the scored position to connect the chamber 42 and the external environment; or a through hole 414 is provided on the housing assembly 4 or the top cover assembly 6, and the pressure relief mechanism 43 is a cover plate 431 covering the housing assembly 4 or the top cover assembly 6. When the internal pressure of the chamber 42 reaches the threshold value, the cover plate 431 disengages from the through hole 414, and the through hole 414 connects the chamber 42 and the external environment.

[0099] The pressure relief groove 44 is provided on one side surface of the housing assembly 4 or the top cover assembly 6 facing the chamber 42, and the pressure relief groove 44 communicates with the chamber 42 and the pressure relief mechanism 43. Specifically, when the battery 2 undergoes thermal runaway and the pressure relief mechanism 43 is not activated, the pressure relief groove 44 communicates with the chamber 42 and the pressure relief mechanism 43, and part of the gas in the chamber 42 can act on the pressure relief mechanism 43 along the pressure relief groove 44 to promote the activation of the pressure relief mechanism 43. Thus, even if the electrode assembly 5 is close to the pressure relief mechanism 43, resulting in a small pressure received by the pressure relief mechanism 43 and a late activation when the battery cell 3 undergoes thermal runaway, the pressure relief groove 44 can guide the gas in the chamber 42 to act on the pressure relief mechanism 43 to assist the activation of the pressure relief mechanism 43;

[0100] And / or, when the pressure relief mechanism 43 is activated during the thermal runaway of the battery 2, the pressure relief groove 44 communicates with the chamber 42 and the pressure relief mechanism 43, and part of the gas in the chamber 42 can flow along the pressure relief groove 44 to the pressure relief mechanism 43 and be released to the outside. Thus, even when the electrode assembly 5 blocks the pressure relief mechanism 43 due to reasons such as uneven pressure in the chamber 42 during the pressure relief process of the pressure relief mechanism 43, the gas in the chamber 42 can also be transmitted to the pressure relief mechanism 43 through the pressure relief groove 44 and released to the outside.

[0101] Optionally, one or more pressure relief grooves 44 can be provided on the housing assembly 4 or the top cover assembly 6. Exemplarily, 1 or 2 or 4 or 5 pressure relief grooves 44 are provided on the housing assembly 4 or the top cover assembly 6.

[0102] Optionally, one or more pressure relief mechanisms 43 can be provided on the housing assembly 4 or the top cover assembly 6.

[0103] Optionally, the shape of the pressure relief groove 44 can be flexibly designed. Exemplarily, the pressure relief groove 44 can be a square groove or a trapezoidal groove, or a chamfer is provided inside the pressure relief groove 44 to improve the die life.

[0104] Please refer to Figure 7 andFigure 8 , Figure 7 is a partial cross-sectional view taken at A-A in Figure 6 in one embodiment of the present application; Figure 8 is a partial cross-sectional view taken at A-A in Figure 6 in another embodiment of the present application.

[0105] In some embodiments, as shown in Figures 6 to 8 , the housing assembly 4 includes a bottom plate 411 disposed opposite to the top cover assembly 6, a first side plate 412 and a second side plate 413 connected to the bottom plate 411. The two first side plates 412 are disposed opposite to each other along the second direction Y, and the two second side plates 413 are disposed opposite to each other along the third direction Z. There is a gap between the electrode assembly 5 and the first side plate 412. The first direction X, the second direction Y, and the third direction Z intersect, and the third direction Z is the thickness direction of the electrode assembly 5. The pressure relief groove 44 and the pressure relief mechanism 43 are both disposed on at least one of the bottom plate 411, the top cover assembly 6, or the first side plate 412.

[0106] In these embodiments, the housing assembly 4 includes a bottom plate 411 disposed opposite to the top cover assembly 6, a first side plate 412 and a second side plate 413 connected to the bottom plate 411. The battery cell 3 has a large expansion amount in the third direction Z. Therefore, the pressure relief mechanism 43 and the pressure relief groove 44 are disposed at the first side plate 412, the bottom plate 411, or the top cover assembly 6 to maintain the structural strength of the second side plate 413. When the battery cell 3 is out of control thermally, the electrode terminal generates more gas in the first direction X. Therefore, the pressure relief mechanism 43 and the pressure relief groove 44 are disposed on the bottom plate 411. The pressure relief groove 44 can fully guide gas to the pressure relief mechanism 43 to improve the pressure relief reliability of the pressure relief mechanism 43. Or when the battery cell 3 is out of control thermally, the gap 45 between the first side plate 41 and the electrode assembly 5 will accumulate gas. Therefore, the pressure relief groove 44 is disposed on the first side plate 412, and the first side plate 412 can help guide this part of the gas to the pressure relief mechanism 43 to improve the pressure relief reliability of the pressure relief mechanism 43.

[0107] The third direction Z is the thickness direction of the electrode assembly 5. The second side plate 413 is in large-area contact with the electrode assembly 5. And when the battery cell 3 is assembled in the battery box 202, the second side plate 413 is in contact with the second side plates 413 of other battery cells 3 or other buffer members or heat exchange members. This results in that when the pressure relief mechanism 43 is disposed on the second side plate 413, other components are easily damaged when the pressure relief mechanism 43 relieves pressure. And the expansion extrusion force of the electrode assembly 5 received by the second side plate 413 is relatively large. Therefore, it should be avoided to dispose the pressure relief mechanism 43 and the pressure relief groove 44 on the second side plate 413, which may cause a decrease in the structural strength of the second side plate 413.

[0108] When the battery cell 3 undergoes thermal runaway, more gas is released by the electrode assembly 5 in the first direction X. Therefore, the pressure relief mechanism 43 and the pressure relief groove 44 provided on the bottom plate 411 or the top cover assembly 6 can fully play the role of pressure relief.

[0109] The pressure relief groove 44 and the pressure relief mechanism 43 are both provided on the bottom plate 411, and there are fewer other parts on the bottom plate 411 or no other parts on the bottom plate 411, which facilitates the extension of the pressure relief groove 44 on the bottom plate 411.

[0110] When the pressure relief groove 44 and the pressure relief mechanism 43 are both provided on the top cover assembly 6, the pressure relief groove 44 is opened on the lower plastic surface of the top cover assembly 6, and the pressure relief groove 44 does not penetrate the lower plastic in the thickness direction of the top cover assembly 6 to maintain the insulation and sealing effects of the lower plastic on the electrode assembly 5 and the top cover assembly 6.

[0111] There is a gap 45 between the first side plate 412 and the electrode assembly 5. The pressure relief groove 44 and the pressure relief mechanism 43 are provided on the same first side plate 412 to release the gas in this gap 45 to the outside.

[0112] In some embodiments, as Figure 6 and Figure 7 shown, the pressure relief mechanism 43 is connected to the gap 45 and one end of the electrode assembly 5 in the first direction X through the pressure relief groove 44.

[0113] In these embodiments, the pressure relief mechanism 43 can be connected to the gap 45 and one end of the electrode assembly 5 in the first direction X through the pressure relief groove 44, so that when the battery cell 3 undergoes thermal runaway, the pressure relief mechanism 43 can fully release the pressure to the outside to improve the reliability of the battery cell 3.

[0114] Specifically, when the pressure relief mechanism 43 is provided on the bottom plate 411 or the top cover assembly 6, one end of the pressure relief groove 44 is connected to the pressure relief mechanism 43, and the other end extends towards the gap 45 in the second direction Y. The projection of the gap 45 in the first direction X coincides with the pressure relief groove 44; or when the pressure relief mechanism 43 is provided on the first side plate 412, one end of the pressure relief groove 44 is connected to the pressure relief mechanism 43, and the other end extends to the bottom plate 411 or the top cover assembly 6.

[0115] In some embodiments, as Figure 6 and Figure 7 shown, the pressure relief mechanism 43 is provided on the first side plate 412. The pressure relief groove 44 includes a first groove 441 and a second groove 442. The first groove 441 is provided on the first side plate 412 and is connected to the pressure relief mechanism 43 and the gap 45. The second groove 442 is provided on at least one of the bottom plate 411 or the top cover assembly 6 and is connected to the gap 45 and one end of the electrode assembly 5 facing the second groove 442.

[0116] In these embodiments, the pressure relief mechanism 43 is disposed on the first side plate 412. The pressure relief groove 44 includes a first groove 441 and a second groove 442. The first groove 441 is disposed on the first side plate 412. The first groove 441 communicates with the pressure relief mechanism 43 and the gap 45. The first groove 441 is configured to guide the gas in the gap 45 to the pressure relief mechanism 43 and release it to the outside. The second groove 442 is disposed on at least one of the bottom plate 411 or the top cover assembly 6 and communicates with the gap 45 and one end of the electrode assembly 5 facing the second groove 442, so that the gas released by the electrode assembly 5 in the first direction X can be transmitted to the gap 45 through the second groove 442 and released to the outside by the pressure relief mechanism 43, thereby improving the reliability of the pressure relief mechanism 43 and reducing the damage caused by thermal runaway of the battery cell 3.

[0117] The pressure relief mechanism 43 is disposed on the first side plate 412. The first groove 441 extends on the first side plate 412 and communicates with the gap 45 and the pressure relief mechanism 43. The first groove 441 and the gap 45 together form a larger pressure relief space to enhance the pressure relief effect of the pressure relief mechanism 43.

[0118] Optionally, the first groove 441 extends over the entire first side plate 412 to improve the pressure relief effect of the first groove 441.

[0119] The second groove 442 is disposed on the bottom plate 411. A part of the second groove 442 in the first direction X is orthogonally projected on the electrode assembly 5, and another part of it is orthogonally projected on the gap 45, so that the second groove 442 communicates with one end of the electrode assembly 5 in the first direction X and the gap 45. Thus, when the battery cell 3 undergoes thermal runaway, the gas released from one end of the electrode assembly 5 in the first direction X can be released into the gap 45 along the second groove 442.

[0120] Optionally, the first groove 441 and the second groove 442 are directly connected, or the first groove 441 and the second groove 442 are connected through the pressure relief mechanism 43 to enhance the pressure relief effect of the pressure relief groove 44.

[0121] In some embodiments, as Figure 6 and Figure 8 shown, both the pressure relief mechanism 43 and the pressure relief groove 44 are disposed on at least one of the bottom plate 411 or the top cover assembly 6, and the pressure relief mechanism 43 communicates with the gap 45 through the pressure relief groove 44.

[0122] In these embodiments, both the pressure relief mechanism 43 and the pressure relief groove 44 are disposed on at least one of the bottom plate 411 or the top cover assembly 6, and the pressure relief mechanism 43 communicates with the gap 45 through the pressure relief groove 44. When the battery cell 3 undergoes thermal runaway, the pressure relief groove 44 can guide the gas in the gap 45 and the gas released from one end of the electrode assembly 5 facing the pressure relief groove 44 to the pressure relief mechanism 43, thereby improving the reliability of the pressure relief mechanism 43 and reducing the risk of thermal propagation caused by thermal runaway of the battery cell 3.

[0123] The pressure relief mechanism 43 is arranged towards the electrode assembly 5 in the first direction X. One end of the pressure relief groove 44 is communicated with the pressure relief mechanism 43, and the other end extends to the gap 45; or the pressure relief mechanism 43 is arranged in the area corresponding to the bottom plate 411 and the gap 45, the pressure relief mechanism 43 is directly communicated with the gap 45, one end of the pressure relief groove 44 is connected to the pressure relief mechanism 43, and the opening of the other end is arranged towards the electrode assembly 5 in the first direction.

[0124] Optionally, the pressure relief grooves 44 are symmetrically arranged on both sides of the pressure relief mechanism 43 to balance the forces on both sides of the pressure relief mechanism 43.

[0125] Please refer to Figure 9 、 Figure 10 and Figure 11 as shown in Figure 9 which is Figure 6 a cross-sectional view taken along line A-A in Figure 10 which is Figure 9 an enlarged schematic structural view of B in Figure 11 and is a schematic structural view of the support mechanism of the battery cell provided by an embodiment of the present application.

[0126] In some embodiments, as Figures 9 to 11 shown, the battery cell 3 further includes a support mechanism 7. The support mechanism 7 is arranged between at least one of the bottom plate 411 and the first side plate 412 and the electrode assembly 5. The support mechanism 7 includes a pressure relief channel 71 communicated with the pressure relief mechanism 43, and the support mechanism 7 and the pressure relief groove 44 are arranged at intervals.

[0127] In these embodiments, the battery cell 3 further includes a support mechanism 7. The support mechanism 7 is arranged between at least one of the bottom plate 411 and the first side plate 412 and the electrode assembly 5. The support mechanism 7 and the pressure relief groove 44 cooperate to form a pressure relief space between the electrode assembly 5 and the pressure relief mechanism 43. The support mechanism 7 includes a pressure relief channel 71 communicated with the pressure relief mechanism 43 to facilitate the pressure relief mechanism 43 to release the pressure in the chamber 42 during thermal runaway, and can improve the problems that the structure strength of the housing assembly 4 decreases due to the over-depth of the pressure relief groove 44 and the support mechanism 7 occupies too much internal space of the chamber 42 on the premise of ensuring the volume of the pressure relief space. The support mechanism 7 and the pressure relief groove 44 are arranged at intervals to improve the problem that the air flow in the pressure relief groove 44 is blocked due to the support mechanism 7 blocking the pressure relief groove 44.

[0128] To alleviate the contradiction that the pressure relief groove 44 can form a pressure relief space but will reduce the structural strength of the housing assembly 4, and that the support mechanism 7 can form a pressure relief space but will occupy the internal space of the chamber 42, a support mechanism 7 is provided in the chamber 42 of the embodiment of the present application. Thus, while ensuring a certain volume of the pressure relief space, the depth of the pressure relief groove 44 is reduced to improve the structural strength of the housing assembly 4, and the volume of the support mechanism 7 is reduced to decrease the occupation of the internal space of the chamber 42 by the support mechanism 7.

[0129] The support mechanism 7 is disposed between the electrode assembly 5 and the pressure relief mechanism 43. The gas of the electrode assembly 5 can reach the pressure relief mechanism 43 through the pressure relief channel 71 on the support mechanism 7. The support mechanism 7 can be in a plate shape, and the pressure relief channel 71 is disposed through the plate-shaped support mechanism 7; or the support mechanism 7 includes a plurality of support blocks arranged at intervals, and the pressure relief channel 71 is located between the support blocks.

[0130] Optionally, the support mechanism 7 is first heat-melted and connected to the mylar film of the electrode assembly 5, and then the combination of the support mechanism 7 and the electrode assembly 5 is placed in the housing assembly 4.

[0131] The support mechanism 7 and the pressure relief groove 44 are arranged at intervals. The support mechanism 7 does not enter the interior of the pressure relief groove 44, the support mechanism 7 does not contact the groove wall of the pressure relief groove 44, and the support mechanism 7 does not block the flow of gas in the pressure relief groove 44.

[0132] In some embodiments, as Figure 9 and Figure 10 shown, the support mechanism 7 covers a part of the pressure relief groove 44, and at least one end of the pressure relief groove 44 facing away from the pressure relief mechanism 43 extends out of the orthographic projection area of the support mechanism 7 in its thickness direction.

[0133] In these embodiments, the support mechanism 7 covers a part of the pressure relief groove 44 to reduce the processing and assembly difficulty of the support mechanism 7. At least one end of the pressure relief groove 44 facing away from the pressure relief mechanism 43 extends out of the orthographic projection area of the support mechanism 7 in its thickness direction to facilitate the gas in the chamber 42 to enter the pressure relief groove 44 and improve the pressure relief efficiency of the pressure relief groove 44.

[0134] The support mechanism 7 is in a flat plate shape. The processing difficulty and assembly requirements of the flat plate-shaped support mechanism 7 are low. The plate-shaped support mechanism 7 covers a part of the notch of the pressure relief groove 44, and the other part of the notch of the pressure relief groove 44 communicates with at least one of the end of the electrode assembly 5 facing the bottom plate 411 or the gap 45.

[0135] Optionally, a communication hole is provided through the support mechanism 7 to communicate the pressure relief groove 44 with the gap 45 and / or the end of the electrode assembly 5 facing the bottom plate 411.

[0136] In some embodiments, as Figures 9 to 11As shown, the support mechanism 7 includes a first support portion 72 and a second support portion 73 , the first support portion 72 is connected to the electrode assembly 5 , and two or more second support portions 73 are arranged at intervals and connected between the first support portion 72 and the shell assembly 4 .

[0137] In these embodiments, the support mechanism 7 includes a first support portion 72 and a second support portion 73, the first support portion 72 is connected to the electrode assembly 5, and more than two second support portions 73 are arranged at intervals and connected between the first support portion 72 and the shell assembly 4, and the second support portion 73 and the pressure relief groove 44 are arranged at intervals. The contact area between the electrode assembly 5 and the support mechanism 7 is increased by the first support portion 72, and the risk of the support mechanism 7 damaging the electrode assembly is reduced. The more than two second support portions 73 are arranged at intervals and connected between the first support portion 72 and the shell assembly 4 to increase the space between the first support portion 72 and the pressure relief groove 44, so as to facilitate the airflow in the chamber 42 to enter the pressure relief groove 44 during thermal runaway, so as to improve the pressure relief effect of the pressure relief groove 44.

[0138] The first support portion 72 is supported on one end of the electrode assembly 5 facing the bottom plate 411, and one end of the second support portion 73 is connected to the side of the first support portion 72 away from the electrode assembly 5, and the other end is connected to the bottom plate 411. At least two second support portions 73 are arranged at intervals. The positive projection of each second support portion 73 in the first direction X is located in the first support portion 72. The first support portion 72 is in contact with the electrode assembly 5 to increase the contact area between the electrode assembly 5 and the support mechanism 7 and reduce the risk of damage to the pole piece. More than two second support portions 73 provide a stable support effect for the first support portion 72. The second support portions 73 arranged at intervals provide a larger communication area for the pressure relief groove 44 and the chamber 42, which facilitates the gas in the chamber 42 to enter the pressure relief groove 44.

[0139] Exemplarily, the four second support portions 73 are respectively connected to diagonal positions of the first support portion 72 to improve the stability of the support mechanism 7 .

[0140] Optionally, the first support portion 72 and the second support portion 73 are integrally formed to reduce the difficulty of preparing the support mechanism 7 .

[0141] In some embodiments, Figures 9 to 11 As shown, the minimum distance L between the second supporting portion 73 and the pressure relief groove 44 is greater than or equal to 0.5 mm.

[0142] In these embodiments, when the minimum spacing between the second support portion 73 and the pressure relief groove 44 meets the above range, the problem of the second support portion 73 blocking the pressure relief groove 44 due to assembly errors between the support mechanism 7 and the shell assembly 4 can be improved.

[0143] Exemplarily, the minimum distance L between the second support portion 73 and the pressure relief groove 44 is 0.5 mm, or 0.6 mm, or 0.75 mm, etc.

[0144] In some embodiments, such as Figure 4 and Figure 5 shown, the pressure relief groove 44 includes a first segment 443 and a second segment 444. Two or more first segments 443 are arranged at intervals in the thickness direction of the electrode assembly 5, and the second segment 444 communicates with each first segment 443.

[0145] In these embodiments, the pressure relief groove 44 includes a first segment 443 and a second segment 444. Two or more first segments 443 are arranged at intervals in the thickness direction of the electrode assembly 5. The spaced-apart first segments 443 help to improve the structural strength of the housing assembly 4, and the second segment 444 communicates with each first segment 443 to increase the overall volume of the pressure relief groove 44 and improve the overall pressure relief efficiency of the pressure relief groove 44.

[0146] Two or more first segments 443 are arranged at intervals in the thickness direction of the electrode assembly 5. One end of the first segment 443 communicates with the pressure relief mechanism 43 so that the gas in the chamber 42 can enter the pressure relief mechanism 43 through the first segment 443. The second segment 444 communicates with each first segment 443 so that the gas can flow in each first segment 443 towards the pressure relief mechanism 43, and the overall area of the pressure relief groove 44 is increased. Moreover, the portion between the spaced-apart first segments 443 or between the spaced-apart second segments 444 can serve as a reinforcing rib to improve the structural strength of the housing assembly 4.

[0147] Exemplarily, the pressure relief groove 44 is provided on the bottom plate 411. Two first segments 443 are arranged at intervals along the third direction Z and extend along the second direction Y, and the second segment 444 extends along the third direction Z to communicate with the two first segments 443.

[0148] Please refer to Figure 12 and Figure 13 , Figure 12 which is a partial structural schematic diagram of the housing assembly of a battery cell provided by an embodiment of the present application; Figure 13 which is a partial structural schematic diagram of the housing assembly of a battery cell provided by an embodiment of the present application.

[0149] In some embodiments, such as Figure 12 and Figure 13As shown, the pressure relief mechanism 43 is a scoring groove 432 provided in the housing assembly 4, and the pressure relief groove 44 communicates with the scoring groove 432; alternatively, a through hole 414 is provided in the housing assembly 4, the pressure relief mechanism 43 is a cover plate 431 covering the through hole 414, and the cover plate 431 is configured to separate from the through hole 414 when the pressure in the chamber 42 reaches a threshold value to release the internal pressure of the chamber 42, and the pressure relief groove 44 communicates with the through hole 414.

[0150] In these embodiments, the pressure relief mechanism 43 is a scoring groove 432 provided in the housing assembly 4, and the pressure relief groove 44 communicates with the scoring groove 432, so that when the battery 2 is out of control thermally, the housing assembly 4 tears at the scoring groove 432, and the gas in the chamber 42 can be released to the outside through the scoring groove 432 along the pressure relief groove 44 to reduce the risk of thermal spread caused by thermal runaway of the battery cell 3; alternatively, a through hole 414 is provided in the housing assembly 4, the pressure relief mechanism 43 is a cover plate 431 covering the through hole 414, and the pressure relief groove 44 communicates with the through hole 414, so that when the battery 2 is out of control thermally, the cover plate 431 separates from the through hole 414, and the gas in the chamber 42 can be released to the outside through the through hole 414 along the pressure relief groove 44 to reduce the risk of thermal spread caused by thermal runaway of the battery cell 3.

[0151] The pressure relief mechanism 43 is a scoring groove 432 provided in the housing assembly 4. The scoring groove 432 can be an unclosed arc or a closed ring. The scoring groove 432 is opened on one surface of the housing assembly 4 facing the electrode assembly 5, and the pressure relief groove 44 communicates with the scoring groove 432; or the scoring groove 432 is provided on the outer surface of the housing assembly 4, then the pressure relief groove 44 intersects or is tangent to the scoring groove 432, so that after the pressure relief mechanism 43 is activated, the gas can reach the tearing position of the scoring groove 432 through the pressure relief groove 44.

[0152] A through hole 414 is provided in the housing assembly 4, the pressure relief mechanism 43 is a cover plate 431 covering the through hole 414, and the cover plate 431 is connected to the housing assembly 4 by bonding or welding. Then the cover plate 431 is provided on the outer surface of the housing assembly 4 and covers the port of the through hole 414, and the pressure relief groove 44 communicates with the through hole 414; or the cover plate 431 is connected to the hole wall of the through hole 414, and one end of the pressure relief groove 44 extends to the hole wall of the through hole 414.

[0153] In some embodiments, such as Figure 4 and Figure 5 shown, in the arrangement direction of the pressure relief groove 44 and the pressure relief mechanism 43, the extension dimension D1 of the pressure relief groove 44 and the dimension D2 of the housing assembly 4 satisfy D1≥0.7*D2.

[0154] In these embodiments, for the extension dimension D1 of the pressure relief groove 44 and the dimension D2 of the housing assembly 4 in the extension direction of the pressure relief groove 44, when D1 and D2 meet the above ranges, the pressure relief groove 44 can effectively guide the gas in the chamber 42 to the pressure relief mechanism 43 when the battery cell 3 undergoes thermal runaway, thereby improving the pressure relief reliability of the pressure relief mechanism 43.

[0155] Optionally, the dimension of the pressure relief groove 44 in the third direction Z is D3, and the dimension of the housing assembly 4 in the third direction Z is D4, satisfying 0.2*D4 ≤ D3 ≤ 0.95*D4, so as to improve the structural strength of the housing assembly 4 while the pressure relief groove 44 has a good pressure relief effect.

[0156] Please refer to Figure 14 , Figure 14 which is a partial structural schematic diagram of the housing assembly of a battery cell provided by an embodiment of the present application.

[0157] In some embodiments, as Figure 4 and Figure 14 shown, for the depth L1 of the pressure relief groove 44 and the thickness L2 of the housing assembly 4, it satisfies L2 / 3 ≤ L1 ≤ L2 / 2.

[0158] In these embodiments, when the depth L1 of the pressure relief groove 44 and the thickness L2 of the housing assembly 4 meet the above ranges, it can form a sufficiently large pressure relief space for the pressure relief groove 44 on the basis of ensuring the structural strength of the housing assembly 4, thereby improving the pressure relief reliability of the pressure relief mechanism 43.

[0159] In a second aspect, as Figure 4 and Figure 5 shown, an embodiment of the present application provides a housing assembly 4, which is applied to the battery cell 3 of any embodiment of the above first aspect. The housing assembly 4 includes a chamber 42 that is at least open at one end in the first direction X and a pressure relief mechanism 43 provided on the housing assembly 4. The pressure relief mechanism 43 is configured to actuate to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold. A pressure relief groove 44 is provided on the surface of the housing assembly 4 facing the chamber 42, and the pressure relief groove 44 communicates with the pressure relief mechanism 43 and the chamber 42.

[0160] In the technical solution of the embodiment of the present application, the housing assembly 4 includes a chamber 42 having at least one open end in the first direction X and a pressure relief mechanism 43 provided on the housing assembly 4. The pressure relief mechanism 43 is configured to be actuated to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold value, so as to reduce the impact on other battery cells 3 after the thermal runaway of the battery cell 3. A pressure relief groove 44 is provided on one side surface of the housing assembly 4 facing the chamber 42. By providing a pressure relief groove 44 on the housing assembly 4 that communicates with the pressure relief mechanism 43 and the chamber 42, when the battery 2 is in thermal runaway, the gas can be guided to the pressure relief mechanism 43 through the pressure relief groove 44 and released to the external environment. The pressure relief groove 44 replaces at least part of the exhaust space formed by the spacer block, so as to improve the reliability of the pressure relief mechanism 43, and the pressure relief groove 44 provided on the housing assembly 4 does not need to additionally occupy the internal space of the housing. Therefore, the utilization rate of the internal space of the housing assembly 4 can be improved, so as to increase the energy density of the battery cell 3.

[0161] In some embodiments, such as Figure 4 and Figure 5 shown, the pressure relief groove 44 includes a first segment 443 and a second segment 444. More than two first segments 443 are spaced apart in the thickness direction of the electrode assembly 5, and the second segment 444 communicates with each first segment 443.

[0162] In these embodiments, the pressure relief groove 44 includes a first segment 443 and a second segment 444. More than two first segments 443 are spaced apart in the thickness direction of the electrode assembly 5. The spaced-apart first segments 443 help to improve the structural strength of the housing assembly 4, and the second segment 444 communicates with each first segment 443 to increase the overall volume of the pressure relief groove 44 and improve the overall pressure relief efficiency of the pressure relief groove 44.

[0163] In some embodiments, such as Figure 12 and Figure 13 shown, the pressure relief mechanism 43 is a scored groove 432 provided on the housing assembly 4, and the pressure relief groove 44 communicates with the scored groove 432; or a through hole 414 is provided on the housing assembly 4, the pressure relief mechanism 43 is a cover plate 431 covering the through hole 414, and the cover plate 431 is configured to disengage from the through hole 414 to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold value, and the pressure relief groove 44 communicates with the through hole 414.

[0164] In these embodiments, the pressure relief mechanism 43 is a scoring groove 432 provided in the housing assembly 4, and the pressure relief groove 44 communicates with the scoring groove 432, so that when the battery 2 is in thermal runaway, the housing assembly 4 tears at the scoring groove 432, and the gas in the chamber 42 can be released to the outside along the pressure relief groove 44 through the tear at the scoring groove 432, so as to reduce the risk of thermal spread caused by the thermal runaway of the battery cell 3; or a through hole 414 is provided on the housing assembly 4, the pressure relief mechanism 43 is a cover plate 431 covering the through hole 414, and the pressure relief groove 44 communicates with the through hole 414, so that when the battery 2 is in thermal runaway, the cover plate 431 detaches from the through hole 414, and the gas in the chamber 42 can be released to the outside along the pressure relief groove 44 through the through hole 414, so as to reduce the risk of thermal spread caused by the thermal runaway of the battery cell 3.

[0165] In a third aspect, the present application provides a battery including the battery cell according to any one of the embodiments of the first aspect above.

[0166] In a fourth aspect, the present application provides an electrical device including the battery according to the embodiment of the third aspect above.

[0167] In some embodiments, such as Figures 1 to 14As shown, the battery cell 3 includes a housing assembly 4, a top cover assembly 6, and an electrode assembly 5. The housing assembly 4 includes a chamber 42 that is open at at least one end in the first direction X; the top cover assembly 6 covers the opening; the electrode assembly 5 is disposed in the chamber 42; wherein, the housing assembly 4 includes a bottom plate 411 disposed opposite to the top cover assembly and a first side plate 412 and a second side plate 413 connected to the bottom plate 411. The two first side plates 412 are disposed opposite to each other in the second direction Y, and the two second side plates 413 are disposed opposite to each other in the third direction Z. There is a gap 45 between the electrode assembly 5 and the first side plate 412. The pressure relief mechanism 43 and the pressure relief groove 44 are both disposed on the bottom plate 411. The pressure relief mechanism 43 communicates with the gap 45 and one end of the electrode assembly 5 facing the pressure relief groove 44 through the pressure relief groove 44. The battery cell 3 further includes a support mechanism 7. The support mechanism 7 is disposed between at least one of the bottom plate 411 and the first side plate 412 and the electrode assembly 5. The support mechanism 7 includes a pressure relief channel 71 that communicates with the pressure relief mechanism 43, and the support mechanism 7 and the pressure relief groove 44 are spaced apart. The support mechanism 7 includes a first support portion 72 and a second support portion 73. The first support portion 72 is connected to the electrode assembly 5. Two or more second support portions 73 are spaced apart and connected between the first support portion 72 and the housing assembly 4. The minimum distance L between the second support portion 73 and the pressure relief groove 44 is greater than or equal to 0.5 mm. The pressure relief groove 44 includes a first segment 443 and a second segment 444. Two or more first segments 443 are spaced apart in the thickness direction of the electrode assembly 5, and the second segment 444 communicates with each first segment 443. In the arrangement direction of the pressure relief groove 44 and the pressure relief mechanism 43, the extension dimension D1 of the pressure relief groove 44 and the dimension D2 of the housing assembly 4 satisfy D1≥0.7*D2. The depth L1 of the pressure relief groove 44 and the thickness L2 of the housing assembly 4 satisfy L2 / 3≤L1≤L2 / 2.

[0168] In the solution of the embodiment of the present application, the battery cell 3 includes a housing assembly 4, a top cover assembly 6, and an electrode assembly 5. The housing assembly 4 includes a chamber 42 that is open at at least one end in the first direction X. The top cover assembly 6 covers the opening. The electrode assembly 5 is disposed in the chamber 42. At least one of the housing assembly 4 or the top cover assembly 6 is provided with a pressure relief mechanism 43. The pressure relief mechanism 43 is configured to actuate to release the internal pressure of the chamber 42 when the pressure in the chamber 42 reaches a threshold value, so as to reduce the impact on other battery cells 3 after thermal runaway of the battery cell 3. A pressure relief groove 44 is provided on one side surface of the housing assembly 4 or the top cover assembly 6 facing the chamber 42. The pressure relief groove 44 communicates with the pressure relief mechanism 43 and the chamber 42. By providing a pressure relief groove 44 on the housing assembly or the top cover assembly that communicates with the pressure relief mechanism 43 and the chamber 42, when the battery 2 undergoes thermal runaway, gas can be guided to the pressure relief mechanism 43 through the pressure relief groove 44 and released to the external environment, so as to improve the reliability of the pressure relief mechanism 43. The pressure relief groove 44 is used to replace at least part of the exhaust space formed by the spacer block, and the pressure relief groove 44 provided in the housing assembly 4 does not need to additionally occupy the internal space of the housing assembly 4. Therefore, the utilization rate of the internal space of the housing assembly 4 can be improved, so as to increase the energy density of the battery cell 3.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit 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 make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the various 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, include: The housing assembly includes a chamber with at least one end open in a first direction; A top cover assembly, covering the opening; An electrode assembly is disposed in the chamber; Among them, at least one of the shell assembly or the top cover assembly is provided with a pressure relief mechanism, and the pressure relief mechanism is configured to be actuated to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold value, and the shell assembly or the top cover assembly is provided with a pressure relief groove on one side surface facing the chamber, and the pressure relief groove is connected to the pressure relief mechanism and the chamber.

2. The battery cell according to claim 1, characterized in that, The shell assembly includes a bottom plate arranged opposite to the top cover assembly and a first side plate and a second side plate connected to the bottom plate, the two first side plates are arranged opposite to each other along a second direction, the two second side plates are arranged opposite to each other along a third direction, there is a gap between the electrode assembly and the first side plate, the first direction, the second direction and the third direction intersect, the third direction is the thickness direction of the electrode assembly, and the pressure relief groove and the pressure relief mechanism are both arranged on at least one of the bottom plate, the top cover assembly or the first side plate.

3. The battery cell according to claim 2, wherein, The pressure relief mechanism is connected to the gap and one end of the electrode assembly in the first direction through the pressure relief groove.

4. The battery cell according to claim 3, wherein, The pressure relief mechanism is arranged on the first side plate, and the pressure relief groove includes a first groove and a second groove, the first groove is arranged on the first side plate and is connected to the pressure relief mechanism and the gap, and the second groove is arranged on at least one of the bottom plate or the top cover assembly, and is connected to the gap and an end of the electrode assembly facing the second groove.

5. The battery cell according to claim 3, characterized in that, The pressure relief mechanism and the pressure relief groove are both arranged on at least one of the bottom plate or the top cover assembly, and the pressure relief mechanism is communicated with the gap through the pressure relief groove.

6. The battery cell according to claim 2, characterized in that, The battery cell further includes a support mechanism, which is disposed between at least one of the bottom plate or the side plate and the electrode assembly, and includes a pressure relief channel connected to the pressure relief mechanism, and the support mechanism and the pressure relief groove are spaced apart.

7. The battery cell according to claim 6, characterized in that, The support mechanism covers a portion of the pressure relief groove, and at least one end of the pressure relief groove that is away from the pressure relief mechanism extends out of the orthographic projection area of the support mechanism in the thickness direction thereof.

8. The battery cell according to claim 6, wherein, The support mechanism includes a first support portion and a second support portion, the first support portion is connected to the electrode assembly, and two or more second support portions are arranged at intervals and connected between the first support portion and the shell assembly.

9. The battery cell according to claim 8, characterized in that, A minimum distance L between the second supporting portion and the pressure relief groove is greater than or equal to 0.5 mm.

10. The battery cell according to any one of claims 1-9, characterized in that, The pressure relief groove includes a first segment and a second segment. Two or more first segments are spaced apart in the thickness direction of the electrode assembly, and the second segment is connected to each of the first segments.

11. The battery cell according to any one of claims 1-9, wherein The pressure relief mechanism is a notched groove arranged on the shell component, and the pressure relief groove is connected to the notched groove; or a through hole is arranged on the shell component, and the pressure relief mechanism is a cover plate covering the through hole, and the cover plate is configured to detach from the through hole to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold value, and the pressure relief groove is connected to the through hole.

12. The battery cell according to any one of claims 1-9, characterized in that, In the arrangement direction of the pressure relief groove and the pressure relief mechanism, the extension dimension D1 of the pressure relief groove and the dimension D2 of the housing assembly satisfy D1 ≥ 0.7 * D2.

13. The battery cell according to claim 1, wherein, The depth L1 of the pressure relief groove and the thickness L2 of the housing assembly satisfy L2 / 3 ≤ L1 ≤ L2 / 2.

14. A housing assembly is applied to the battery cell according to any one of claims 1-13 above, characterized in that, The housing assembly includes a chamber having at least one open end in a first direction and a pressure relief mechanism provided on the housing assembly. The pressure relief mechanism is configured to be actuated to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold. A pressure relief groove is provided on a surface of the housing assembly facing the chamber, and the pressure relief groove communicates with the pressure relief mechanism and the chamber.

15. The housing assembly according to claim 14, characterized in that, The pressure relief groove includes a first segment and a second segment. Two or more first segments are spaced apart in the thickness direction of the electrode assembly, and the second segment communicates with each of the first segments.

16. The housing assembly according to claim 14, wherein, The pressure relief mechanism is a scoring groove provided on the housing assembly, and the pressure relief groove and the scoring groove communicate; or a through hole is provided on the housing assembly, the pressure relief mechanism is a cover plate covering the through hole, and the cover plate is configured to disengage from the through hole to release the internal pressure of the chamber when the pressure in the chamber reaches a threshold, and the pressure relief groove and the through hole communicate.

17. A battery, characterized in that, A battery cell includes any one of the above claims 1-13.

18. An electrical device, characterized in that, A battery includes the battery according to the above claim 17.

Images