Battery cell, battery pack, and electrical apparatus

Abstract

The present disclosure relates to the technical field of batteries. Disclosed are a battery cell, a battery pack, and an electrical apparatus. The battery cell comprises a casing, a bare battery cell, and a pressure relief structure. An accommodating cavity is formed in the casing. The bare battery cell is accommodated in the accommodating cavity. The pressure relief structure is mounted on a first wall surface of the casing and used for being actuated to communicate the accommodating cavity with an external space when the pressure or temperature in the accommodating cavity reaches a threshold. The first wall surface forms a protrusion structure protruding towards the interior of the accommodating cavity, and the protrusion structure abuts against the bare battery cell so as to form a flow channel between the bare battery cell and the first wall surface.

Description

Battery cell, battery pack and power-consuming device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on the Chinese patent application with application number 202321935563.0, application date July 21, 2023, and invention name “A battery cell, a battery pack and an electrical device”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into the present disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to battery cells, battery packs, and electrical devices. Background Art

[0004] New energy batteries are being used more and more widely in life and industry. For example, new energy vehicles equipped with batteries have been widely used. In addition, batteries are also being increasingly used in energy storage fields.

[0005] In the related art, there is a risk of explosion of battery cells during operation.

[0006] Utility Model Content

[0007] In order to solve the above technical problems, the present disclosure provides a battery cell, a battery pack and an electrical device to reduce the risk of battery cell explosion.

[0008] The present disclosure is achieved through the following technical solutions.

[0009] A first aspect of an embodiment of the present disclosure provides a battery cell, including:

[0010] The outer shell forms a receiving cavity therein;

[0011] A bare battery cell is accommodated in the accommodation cavity;

[0012] a pressure relief structure, mounted on the first wall of the housing, and configured to be actuated to connect the housing chamber with an external space when the pressure or temperature in the housing chamber reaches a threshold;

[0013] The first wall surface forms a protruding structure protruding toward the interior of the accommodating cavity, and the protruding structure is used to abut against the bare battery cell to form a flow channel for fluid to flow between the bare battery cell and the first wall surface.

[0014] The battery cell of the embodiment of the present disclosure has a protruding structure protruding toward the inside of the accommodating cavity that abuts against the bare battery cell in the accommodating cavity, and a flow channel for fluid to flow through is formed between the bare battery cell and the first wall. The gas generated by thermal runaway of the battery cell can flow smoothly to the pressure relief structure through the flow channel and be discharged out of the shell through the pressure relief structure. The formation of the flow channel reduces the airflow resistance at the corner position adjacent to the flow channel in the shell, which is conducive to smooth exhaust, thereby reducing the risk of explosion of the battery cell.

[0015] In one embodiment, the distance that the protruding structure protrudes from the first wall surface is a first dimension, and the first dimension is D1, which satisfies 0.5 mm ≤ D1 ≤ 5 mm.

[0016] In the embodiment of the present disclosure, the first dimension can be greater than or equal to 0.5 mm, and the first dimension can be less than or equal to 5 mm. In the event of thermal runaway of the battery cell, the flow channel between the bare battery cell and the first wall surface can have sufficient space to allow for smooth exhaust and reduce the risk of explosion, while the space within the outer shell can be more fully utilized.

[0017] In one embodiment, the first dimension satisfies 2 mm ≤ D1 ≤ 3 mm.

[0018] In the embodiment of the present disclosure, the first size is limited to a relatively suitable range, so that the flow channel can discharge the gas in the accommodating cavity more smoothly, reduce the risk of battery cell explosion, and make full use of the space in the shell.

[0019] In one embodiment, the shape of the shell is a rectangular parallelepiped, the distance that the protruding structure protrudes from the first wall surface is a first dimension, the ratio of the first dimension to the width of the shell is a first ratio, the unit of the first dimension is the same as the unit of the width of the shell, and the first ratio is K1, satisfying 0.01≤K1≤0.5.

[0020] In the embodiment of the present disclosure, the first ratio is within a relatively suitable range, which can not only reduce the risk of explosion of the battery cell in the event of thermal runaway, but also make full use of the space in the housing.

[0021] In one embodiment, the first ratio satisfies 0.2≤K1≤0.3.

[0022] In the embodiment of the present disclosure, the first ratio is limited to a relatively suitable range, which can not only enable the flow channel to exhaust more smoothly to reduce the risk of battery cell explosion, but also fully utilize the space inside the shell to arrange bare cells, so that the space inside the shell is fully utilized.

[0023] In one embodiment, the distance that the protruding structure protrudes from the first wall surface is a first dimension, and the ratio of the first dimension to the battery energy density is a second ratio. The unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, and the second ratio is K2, satisfying 0.0007≤K2≤0.01.

[0024] In the embodiment of the present disclosure, the second ratio is greater than or equal to 0.0007, the second ratio is less than or equal to 0.01, and the second ratio is limited to a more appropriate range. When thermal runaway occurs in the battery cell, the range defined by the second ratio makes it possible to have sufficient space in the flow channel formed between the bare cell and the first wall at the corresponding energy density, so that the gas can be discharged more smoothly through the flow channel, thereby reducing the risk of explosion of the battery cell in the event of thermal runaway. The range defined by the second ratio makes it possible to fully utilize the space in the outer shell to accommodate the bare cell, so that the space in the outer shell can be fully utilized.

[0025] In one embodiment, the second ratio satisfies 0.001≤K2≤0.008.

[0026] In the embodiment of the present disclosure, the second ratio is within a relatively suitable range, which can not only reduce the risk of explosion of the battery cell in the event of thermal runaway, but also fully utilize the space in the casing to accommodate the bare battery cell.

[0027] In one embodiment, the distance that the protruding structure protrudes from the first wall surface is a first dimension, the first dimension is D1, and satisfies 0.5mm≤D1≤5mm. The shape of the shell is a rectangular parallelepiped, the ratio of the first dimension to the width of the shell is a first ratio, the first ratio is K1, and satisfies 0.01≤K1≤0.5. The unit of the first dimension is the same as the unit of the width of the shell. The ratio of the first dimension to the battery energy density is a second ratio, the unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, the second ratio is K2, and satisfies 0.0007≤K2≤0.01. The width of the shell is D2, and satisfies 10≤D2≤100. The battery energy density is E, and satisfies 500≤E≤1000.

[0028] In the embodiment of the present disclosure, since the three parameters of the first size, the battery energy density and the width of the shell are all related to the exhaust smoothness of the flow channel and the space utilization inside the shell, when these three parameters satisfy 0.5≤D1≤5, 10≤D2≤100, 500≤E≤1000, 0.01≤D1 / D2≤0.5, 0.0007≤D1 / E≤0.01, the three parameters are roughly limited to a more appropriate range, so that the gas generated by the battery cell in the case of thermal runaway can be smoothly discharged from the shell, the battery cell will basically not explode in the case of thermal runaway, and the space inside the shell can be more fully used to accommodate bare battery cells.

[0029] In one embodiment, the first dimension satisfies 2mm≤D1≤3mm, the first ratio satisfies 0.2≤K1≤0.3, the second ratio satisfies 0.001≤K2≤0.008, the width of the shell satisfies 20≤D2≤80, and the battery energy density satisfies 600≤E≤900.

[0030] In the embodiment of the present disclosure, the first dimension, the width of the shell and the battery energy density are roughly limited to a relatively suitable range, so that the gas generated by the battery cell in the event of thermal runaway can be smoothly discharged from the shell, the battery cell will basically not explode in the event of thermal runaway, and the space in the shell can be more fully used to accommodate bare battery cells.

[0031] In one embodiment, the outer shell includes an end cover assembly, a pole and a shell, the end cover assembly and the shell are arranged to form the accommodating cavity, the pole is installed on the end cover assembly, the pole is electrically connected to the bare battery cell, and the first wall is located in the shell.

[0032] In the embodiment of the present disclosure, the first wall is located in the shell, and the position of the pressure relief structure installed on the first wall avoids the pole installed in the end cover assembly. The exhaust direction of the pressure relief structure is not toward the pole, which can reduce the damage to the insulating material of the pole caused by the high-temperature gas discharged by the pressure relief structure in the event of thermal runaway, and reduce the risk of short circuit of the battery cell.

[0033] In one embodiment, the shell is made of metal.

[0034] In the disclosed embodiment, the metal material is relatively hard, and the metal material of the shell is beneficial for protecting the bare battery cells located within the shell. Furthermore, the shell is made of metal, and the first wall surface of the shell and the raised structure formed on the first wall surface are all made of metal. Metal materials can withstand high temperatures. Even if the raised structure made of metal is exposed to high-temperature gases generated by thermal runaway, the raised structure can still separate the bare battery cells from the first wall surface to form a flow channel for fluid to flow through, allowing for smooth exhaust in the event of thermal runaway of the battery cells.

[0035] In one embodiment, the pressure relief structure and the pole are arranged opposite to each other, the pressure relief structure is located at one end of the shell, and the pole is located at the other end of the shell.

[0036] In the embodiment of the present disclosure, since the pressure relief structure and the pole are arranged relative to each other, the pressure relief structure is located at one end of the shell and the pole is located at the other end of the shell, the direction in which the gas is discharged from the pressure relief structure is almost opposite to that of the pole. In the event of thermal runaway, the risk of short circuit caused by the high-temperature gas discharged from the pressure relief structure damaging the insulating material on the pole is reduced.

[0037] In one embodiment, the protruding structure has a weight-reducing cavity, and the weight-reducing cavity is located on a side of the protruding structure away from the accommodating cavity.

[0038] In the embodiments of the present disclosure, the weight-reducing cavity is located on the side of the raised structure facing away from the accommodating cavity. This positioning of the weight-reducing cavity does not affect the protrusion of the raised structure toward the bare battery cell. Furthermore, the weight-reducing cavity helps reduce the weight of the raised structure, thereby contributing to the lightweighting of the battery cell. Furthermore, the weight-reducing cavity is located on the side of the raised structure facing away from the accommodating cavity, allowing the raised structure to be formed by stamping on the first wall, making the processing of the raised structure relatively simple and convenient.

[0039] In one embodiment, a distance that the protruding structure protrudes from the first wall surface is greater than a distance that the protruding structure protrudes from the pressure relief structure.

[0040] In the embodiment of the present disclosure, since the distance that the protruding structure protrudes from the first wall surface is greater than the distance that the protruding structure protrudes from the pressure relief structure, the exhaust space at the pressure relief structure is larger, which is conducive to the gas generated by thermal runaway to converge and discharge to the pressure relief structure, thereby reducing the risk of battery cell explosion.

[0041] A second aspect of the present disclosure provides a battery pack, including:

[0042] Box;

[0043] Any of the above battery cells is located in the box.

[0044] A third aspect of the present disclosure provides an electrical device, characterized by comprising:

[0045] Device body;

[0046] A power supply device is used to supply power to the device body, and the power supply device includes any one of the above-mentioned battery cells or any one of the above-mentioned battery packs.

[0047] Utility model effect:

[0048] By virtue of the protruding structure protruding toward the interior of the accommodating cavity in the embodiment of the present disclosure abutting against the bare battery cell in the accommodating cavity, a flow channel for fluid to flow through is formed between the bare battery cell and the first wall surface. The gas generated by thermal runaway of the battery cell can flow smoothly to the pressure relief structure through the flow channel and be discharged out of the outer shell through the pressure relief structure. The formation of the flow channel reduces the airflow resistance at the corner position adjacent to the flow channel in the outer shell, which is conducive to smooth exhaust, thereby reducing the risk of explosion of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present disclosure. The same reference numerals are used throughout the drawings to denote the same components. In the drawings:

[0050] FIG1 is an exploded view of a battery cell according to an embodiment of the present disclosure, in which the terminal is located at the upper end of the housing and the pressure relief structure is located at the lower end of the housing;

[0051] FIG2 is a schematic structural diagram of a housing according to an embodiment of the present disclosure, in which the opening of the accommodating cavity faces upward and the pressure relief structure is located at the lower end of the housing;

[0052] FIG3 is an exploded view of a battery cell according to an embodiment of the present disclosure, in which end cap assemblies are provided at opposite ends of the housing along the length direction;

[0053] FIG4 is a schematic structural diagram of a housing according to an embodiment of the present disclosure, in which the accommodating cavity is open at both ends along the length direction of the housing, and the pressure relief structure is located at the lower end of the housing;

[0054] FIG5 is a schematic structural diagram of a housing according to an embodiment of the present disclosure, showing a protruding structure protruding into the accommodating cavity;

[0055] FIG. 6 is an enlarged view of position A in FIG. 5 .

[0056] Explanation of the reference numerals: housing 1; accommodating cavity 11; shell 12; first wall 13; bare cell 2; end cap assembly 3; cover body 31; protective patch 32; pole 4; pressure relief structure 5; valve body 51; protective film 52; protruding structure 6; weight reduction cavity 62; support plate 7; Mylar film 8; adapter 9. DETAILED DESCRIPTION

[0057] The following embodiments of the technical solution of the present disclosure are described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present disclosure and are therefore only examples and are not intended to limit the scope of protection of the present disclosure.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure; the terms "including" and "having" and any variations thereof in the specification and claims of the present disclosure and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0059] In the description of the embodiments of the present disclosure, technical terms such as "first," "second," and "third" are used solely to distinguish different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0060] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] In the description of the embodiments of the present disclosure, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0062] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "width", "inside", "outside", "bottom", "upper", and "lower" are based on the orientations or positional relationships shown in Figures 1 and 3. They are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present disclosure.

[0063] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0064] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0065] Currently, new energy batteries are increasingly being used in everyday life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application of power batteries continues to expand, market demand is also growing.

[0066] As part of the creative concept of the present disclosure, before describing the embodiments of the present disclosure, it is necessary to analyze the causes of battery cell explosions in related technologies and obtain the technical solutions of the embodiments of the present disclosure through reasonable analysis.

[0067] In related technologies, the bare cell of a battery cell is located within the housing of a casing. When a thermal runaway occurs in the battery cell, a large amount of gas is generated within the housing. This gas needs to be discharged promptly to avoid causing an explosion of the battery cell. The gas in the housing is discharged through a pressure relief structure. Since the bare cell and the inner surface of the casing are almost in contact, it is difficult to form a relatively smooth flow channel, resulting in high exhaust resistance. In addition, the near-contact between the bare cell and the inner surface of the casing causes high airflow and fluid resistance at the corners of the housing, which is not conducive to exhaust through the pressure relief structure installed on the casing, and there is a risk of explosion of the battery cell.

[0068] If a flow channel can be formed by separating the bare battery cells from the outer shell at a certain distance, the gas in the housing cavity can flow smoothly through the flow channel to the pressure relief structure, thereby discharging the gas and reducing the risk of battery cell explosion. Therefore, by providing a raised structure on the first wall of the outer shell, a certain distance is separated between the first wall of the outer shell and the bare battery cells, forming a flow channel and reducing the risk of battery cell explosion.

[0069] The solutions of the embodiments of the present disclosure can be applied, but are not limited to, to battery cells, battery modules including multiple battery cells, or battery packs including battery cells or battery modules. They can also be applied to electrical devices including battery cells and battery packs. The raised structure 6 separates the first wall 13 of the battery cell's housing 1 from the bare cell 2 to form a flow channel, thereby reducing the risk of battery cell explosion. The risk of explosion of a single battery cell is reduced, as is the risk of a battery module including a battery cell, the risk of a battery pack including a battery cell, and the risk of an electrical device including a battery pack.

[0070] An electrical device is a device that uses electricity as an energy source and consumes it to achieve its corresponding function. For example, an electrical device may include, but is not limited to, a mobile phone, tablet computer, laptop computer, electric toy, power tool, battery-powered vehicle, electric vehicle, ship, spacecraft, etc. Electric toys may include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys. Spacecraft may include airplanes, rockets, space shuttles, and spacecraft, etc.

[0071] The electric device of the embodiment of the present disclosure may include a device body and a power supply device, the power supply device is used to supply power to the device body, and the power supply device may include a battery cell or a battery pack.

[0072] The "device body" refers to the main structure that consumes electrical energy to perform its corresponding functions. For example, a power-consuming device could be a mobile phone, where the "device body" is the portion that performs functions such as communication, and power is supplied to this portion via a battery cell or battery pack. For example, a power-consuming device could be a car, where the "device body" is the portion that provides passengers with a seat and allows them to travel on the road, and power is supplied to this portion via a battery cell or battery pack.

[0073] A power supply device is a device that can output electrical energy. For example, electrical energy can be output through a battery cell. For example, electrical energy can be output through a battery pack composed of battery cells. For example, electrical energy can be output through a battery module composed of battery cells.

[0074] The electric device according to an embodiment of the present disclosure is described as a vehicle as an example.

[0075] The vehicle provided in one embodiment of the present disclosure may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery pack is provided inside the vehicle, and the battery pack may be provided at the bottom, head or tail of the vehicle. The battery pack may be used to power the vehicle. For example, the battery pack may serve as an operating power source for the vehicle. The vehicle may also include a controller and a motor, and the controller may be used to control the battery pack to power the motor. For example, the battery pack may be used for starting, navigating and operating power requirements of the vehicle during driving.

[0076] In some embodiments of the present disclosure, the battery pack can serve not only as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0077] The battery pack of the embodiment of the present disclosure may include a box body and battery cells, wherein the battery cells are located in the box body.

[0078] The box body refers to a structure with a receiving space, and the battery cells are located in the box body, and the box body receives the battery cells of the battery pack.

[0079] The number of battery cells can be multiple, and the multiple battery cells can be connected in series, in parallel, or in a mixed connection. Mixed connection means that the multiple battery cells are connected both in series and in parallel. The multiple battery cells can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells is placed in a box. Of course, the multiple battery cells can first be connected in series, in parallel, or in a mixed connection to form a battery module, and the multiple battery modules can then be connected in series, in parallel, or in a mixed connection to form a whole, and the whole formed by the multiple battery modules connected in series, in parallel, or in a mixed connection can be placed in a box. The battery pack can also include other structures. For example, the battery pack can also include a busbar component for achieving electrical connection between the multiple battery cells.

[0080] A battery cell refers to the basic unit that can realize the mutual conversion of chemical energy and electrical energy.

[0081] In the embodiment of the present disclosure, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0082] In the embodiments of the present disclosure, the battery cells may be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., but the embodiments of the present disclosure are not limited to this.

[0083] The battery cell of the embodiment of the present disclosure, please refer to Figures 1, 3 and 5. The battery cell may include a shell 1, a bare cell 2 and a pressure relief structure 5. The shell 1 has a accommodating cavity 11. The bare cell 2 is located in the accommodating cavity 11. The pressure relief structure 5 is mounted on the first wall 13 of the shell 1. The pressure relief structure 5 is used to actuate when the pressure or temperature in the accommodating cavity 11 reaches a threshold value to connect the accommodating cavity 11 with the external space. Among them, the first wall 13 forms a protruding structure 6 protruding toward the inside of the accommodating cavity 11, and the protruding structure 6 is used to abut against the bare cell 2 to form a flow channel between the bare cell 2 and the first wall 13 for fluid to flow through.

[0084] The housing 1 is mainly used to accommodate the bare battery cell 2 , and the housing 1 plays a certain protective role on the bare battery cell 2 in the accommodating cavity 11 .

[0085] For example, the shape of the housing 1 can be a cuboid or a cylinder. When the shape of the housing 1 is a cuboid, the corresponding battery cell is a square battery cell, and when the shape of the housing 1 is a cylinder, the corresponding battery cell is a cylindrical battery cell.

[0086] The accommodating cavity 11 refers to the accommodating space inside the housing 1 , and is used to accommodate the bare battery cell 2 .

[0087] The bare battery cell 2 is the main structure for converting chemical energy into electrical energy.

[0088] For example, the bare cell 2 may include a positive electrode sheet, a negative electrode sheet, and a separator. During the charge and discharge process of the battery cell, active ions (e.g., lithium ions) are intercalated and released between the positive and negative electrodes. The separator is disposed between the positive and negative electrodes to prevent a short circuit between the positive and negative electrodes while allowing the active ions to pass through.

[0089] It is understandable that the bare cell 2 has two different process structures.

[0090] Illustratively, the positive electrode sheet, the negative electrode sheet, and the separator are wound as a whole in one direction, and the obtained battery cell is a wound battery cell.

[0091] Illustratively, the positive electrode sheet, the negative electrode, and the separator are folded back and forth as a whole, and the resulting battery cell is a laminated battery cell.

[0092] Exemplarily, the bare cell 2 may further include tabs, and the positive electrode sheet and the negative electrode sheet are electrically connected to the corresponding tabs respectively.

[0093] The pressure relief structure 5 is a structure capable of discharging the gas in the accommodating cavity 11 to the outside of the housing 1 . When a battery cell experiences thermal runaway and a large amount of gas is generated in the accommodating cavity 11 , the gas in the accommodating cavity 11 can be discharged through the pressure relief structure 5 .

[0094] Exemplarily, the pressure relief structure 5 is an explosion-proof valve.

[0095] Exemplarily, the explosion-proof valve is in the shape of a sheet.

[0096] The protruding structure 6 refers to a structure protruding from the first wall surface 13 .

[0097] For example, the number of the protruding structures 6 may be one or more.

[0098] For example, the shape of the protruding structure 6 may be square, or the shape of the protruding structure 6 may be circular.

[0099] In the battery cell of the embodiment of the present disclosure, since the protruding structure 6 protruding toward the inside of the accommodating cavity 11 abuts against the bare battery cell 2 in the accommodating cavity 11, a flow channel for fluid to flow through is formed between the bare battery cell 2 and the first wall 13. The gas generated by thermal runaway of the battery cell can flow smoothly to the pressure relief structure 5 through the flow channel and be discharged out of the outer shell 1 through the pressure relief structure 5. The formation of the flow channel makes the airflow resistance at the corner position adjacent to the flow channel in the outer shell 1 smaller, which is conducive to smooth exhaust, thereby reducing the risk of explosion of the battery cell.

[0100] For example, please refer to FIG5 , in which the gas flows along the arrows indicating the gas flow direction, and the positions where the arrows indicating the gas flow direction bend are approximately corner positions.

[0101] In one embodiment, referring to FIG. 5 and FIG. 6 , the distance that the protruding structure 6 protrudes from the first wall surface 13 is a first dimension, and the first dimension is D1 .

[0102] When the raised structure 6 contacts the bare cell 2 within the accommodating cavity 11, the first dimension roughly represents the minimum dimension of the flow channel formed between the bare cell 2 and the first wall 13. When the raised structure 6 loses contact with the bare cell 2 within the accommodating cavity 11, the distance between the bare cell 2 and the first wall 13 can be greater than the first dimension. Therefore, the first dimension roughly represents the size of the flow channel for fluid flow.

[0103] For example, the first dimension is measured before a thermal runaway test is performed on a produced battery cell, and the measurement may be performed at a normal temperature, for example, at an ambient temperature of 25°C.

[0104] For example, before the produced battery cells are subjected to thermal runaway tests, they are measured by CT scanning.

[0105] For example, the method for conducting the thermal runaway test may be to pierce the battery cell with a needle to short-circuit the positive electrode and the negative electrode of the battery cell, thereby causing thermal runaway.

[0106] In one embodiment, referring to FIG. 6 , the first dimension satisfies 0.5 mm ≤ D1 ≤ 5 mm.

[0107] Illustratively, the first size may be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.1 mm, 2.3 mm, 2.6 mm, 2.8 mm, 2.9 mm, 3 mm, 3.3 mm, 4.1 mm, 4.8 mm, or 5 mm.

[0108] In the disclosed embodiment, the first dimension satisfies 0.5mm≤D1≤5mm. In the event of thermal runaway of the battery cell, the flow channel between the bare cell 2 and the first wall 13 can have sufficient space to allow for smooth exhaust, thereby reducing the risk of explosion, and the space within the outer shell 1 can be more fully utilized.

[0109] In one embodiment, referring to the figure, the first dimension satisfies 2mm≤D1≤3mm.

[0110] In the embodiment of the present disclosure, the first size is limited to a relatively suitable range, so that the flow channel can discharge the gas in the accommodating cavity 11 relatively smoothly, reduce the risk of battery cell explosion, and make full use of the space in the shell.

[0111] It is understandable that the first dimension of the embodiment of the present disclosure is not limited to satisfying 0.5 mm ≤ D1 ≤ 5 mm. The protruding structure 6 protrudes toward the interior of the accommodating cavity 11 and can abut against the battery cell 2 in the accommodating cavity 11 .

[0112] In one embodiment, referring to FIG. 6 , the housing 1 is in the shape of a cuboid, the ratio of the first dimension to the width of the housing 1 is a first ratio, the unit of the first dimension is the same as the unit of the width of the housing 1 , and the first ratio is K1.

[0113] The first ratio refers to the ratio of the first dimension to the width of the housing 1 .

[0114] For example, referring to FIG. 2 , FIG. 3 and FIG. 6 , the first dimension is D1 , the width of the housing 1 is D2 , and K1 = D1 / D2 .

[0115] The unit of the first dimension is the same as the unit of the width of the housing 1 , and the first ratio is a dimensionless percentage and has no unit.

[0116] For example, the width of the housing 1 is measured before the produced battery cells are subjected to a thermal runaway test.

[0117] For example, before the thermal runaway test of the produced battery cells is carried out, the width of the housing 1 is measured by CT scanning.

[0118] In the embodiment of the present disclosure, the larger the width of the shell 1, the larger the pressure-bearing area of ​​the first wall 13, and the greater the pressure load on the first wall 13. It is necessary to increase the first dimension to facilitate smoother exhaust and reduce the pressure load in the accommodating cavity 11. The first dimension and the width of the shell 1 are associated through the first ratio, and the corresponding first dimension can be set according to the width of the shell 1.

[0119] In one embodiment, referring to FIG. 2 , FIG. 3 and FIG. 6 , the first ratio satisfies 0.01≤K1≤0.5.

[0120] Illustratively, 0.01≤K1≤0.5, that is, 0.01≤D1 / D2≤0.5.

[0121] Illustratively, the first ratio may be 0.01, 0.02, 0.06, 0.1, 0.13, 0.15, 0.18, 0.2, 0.21, 0.23, 0.25, 0.26, 0.28, 0.29, 0.3, 0.31, 0.35, 0.4, 0.46, or 0.5.

[0122] In the disclosed embodiment, the first ratio satisfies 0.01≤K1≤0.5, placing the first ratio within a relatively suitable range. Given the corresponding width of the housing 1, the first dimension is sufficiently large, allowing the flow channel formed between the bare cell 2 and the first wall 13 to have sufficient space for relatively smooth exhaust, thereby reducing the risk of explosion of the battery cell in the event of thermal runaway. The first ratio satisfies 0.01≤K1≤0.5, placing the first ratio within a relatively suitable range. The space within the housing 1 can be more fully utilized to arrange the bare cell 2, ensuring full utilization of the space within the housing 1.

[0123] In one embodiment, referring to the figure, the first ratio satisfies 0.2≤K1≤0.3.

[0124] In the embodiment of the present disclosure, the first ratio is limited to a relatively suitable range, which can not only enable the flow channel to exhaust more smoothly to reduce the risk of battery cell explosion, but also fully utilize the space inside the shell 1 to arrange the bare battery cells 2, so that the space inside the shell 1 is fully utilized.

[0125] It is understandable that the first ratio is not limited to satisfying 0.01≤K1≤0.5. The protruding structure 6 protrudes toward the interior of the accommodating cavity 11 and can abut against the bare battery cell 2 in the accommodating cavity 11.

[0126] In one embodiment, referring to FIG6 , the ratio of the first dimension to the battery energy density is a second ratio, the unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, and the second ratio is K2.

[0127] The symbol for millimeter is mm.

[0128] The symbol for the unit watt-hour / liter is Wh / L, where watt is the unit of power, hour is the unit of time, and liter is the unit of volume.

[0129] The second ratio refers to the first size to the battery energy density.

[0130] For example, referring to FIG. 6 , the first dimension is D1 , the battery energy density is E, and K2 = D1 / E.

[0131] The unit of the first dimension is millimeter, the unit of battery energy density is watt-hour / liter, and the unit of the second ratio is milliliter / watt-hour, and the symbol of milliliter / watt-hour is mmL / Wh.

[0132] In the disclosed embodiment, the greater the battery energy density of the battery cell, the greater the amount of gas generated in the same time in the case of thermal runaway, and the greater the need for smoother exhaust as possible to reduce the risk of battery cell explosion. The first size and the battery energy density are associated through the second ratio.

[0133] In one embodiment, the second ratio satisfies 0.0007≤K2≤0.01.

[0134] Illustratively, 0.0007≤K2≤0.01, that is, 0.0007≤D1 / E≤0.01.

[0135] Illustratively, the second ratio may be 0.0007, 0.0008, 0.0009, 0.001, 0.0015, 0.002, 0.0025, 0.003, 0.0035, 0.004, 0.0045, 0.005, 0.006, 0.007, 0.0076, 0.008, 0.0081, 0.0085, 0.0086, 0.009, or 0.01.

[0136] In the embodiment of the present disclosure, the second ratio satisfies 0.0007≤K2≤0.01, and the second ratio is limited to a relatively appropriate range. When thermal runaway occurs in the battery cell, the range defined by the second ratio allows for sufficient space in the flow channel formed between the bare cell 2 and the first wall 13 at the corresponding energy density, so that the gas can be discharged more smoothly through the flow channel, thereby reducing the risk of explosion of the battery cell in the event of thermal runaway. The range defined by the second ratio allows for full utilization of the space inside the outer shell 1 to accommodate the bare cell 2, thereby fully utilizing the space inside the outer shell 1.

[0137] In one embodiment, the second ratio satisfies 0.001≤K2≤0.008.

[0138] In the embodiment of the present disclosure, the second ratio is within a relatively suitable range, which can not only reduce the risk of explosion of the battery cell in the event of thermal runaway, but also fully utilize the space in the housing 1 to accommodate the bare battery cell 2.

[0139] It is understandable that the second ratio is not limited to satisfying 0.0007≤K2≤0.01. The protruding structure 6 protrudes toward the interior of the accommodating cavity 11 and can abut against the bare battery cell 2 in the accommodating cavity 11.

[0140] In one embodiment, referring to FIG6 , the first dimension satisfies 0.5 mm ≤ D1 ≤ 5 mm, the first ratio satisfies 0.01 ≤ K1 ≤ 0.5, the second ratio satisfies 0.0007 ≤ K2 ≤ 0.01, the width of the housing 1 satisfies 10 ≤ D2 ≤ 100, and the battery energy density satisfies 500 ≤ E ≤ 1000.

[0141] For example, the width of the housing 1 may be 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100.

[0142] Illustratively, the battery energy density may be 500, 600, 700, 800, 900, or 1000.

[0143] In the embodiment of the present disclosure, since the three parameters of the first size, the battery energy density and the width of the shell 1 are all related to the exhaust smoothness of the flow channel and the space utilization rate inside the shell 1, when these three parameters satisfy 0.5≤D1≤5, 10≤D2≤100, 500≤E≤1000, 0.01≤D1 / D2≤0.5, 0.0007≤D1 / E≤0.01, these three parameters are roughly limited to a more appropriate range, so that the gas generated by the battery cell in the case of thermal runaway can be smoothly discharged from the shell 1, the battery cell will basically not explode in the case of thermal runaway, and the space inside the shell 1 can be more fully used to accommodate the bare battery cell 2.

[0144] In one embodiment, the first dimension satisfies 2mm≤D1≤3mm, the first ratio satisfies 0.2≤K1≤0.3, the second ratio satisfies 0.001≤K2≤0.008, the width of the shell satisfies 20≤D2≤80, and the battery energy density satisfies 600≤E≤900.

[0145] In the embodiment of the present disclosure, the first dimension, the width of the shell and the battery energy density are roughly limited to a relatively suitable range, so that the gas generated by the battery cell in the event of thermal runaway can be smoothly discharged from the shell 1, the battery cell will basically not explode in the event of thermal runaway, and the space inside the shell 1 can be more fully used to accommodate the bare battery cell 2.

[0146] It is understood that the width of the housing in the embodiment of the present disclosure is not limited to satisfying 10≤D2≤100. The battery energy density in the embodiment of the present disclosure is not limited to satisfying 500≤E≤1000. The width of the housing and the battery energy density can be set according to actual needs.

[0147] In one embodiment, the outer shell includes an end cover assembly 3, a pole 4 and a shell 12. The end cover assembly 3 and the shell 12 are arranged to form a accommodating cavity 11. The pole 4 is installed on the end cover assembly 3. The pole 4 is electrically connected to the bare battery cell 2. The first wall 13 is located in the shell 12.

[0148] The end cap assembly 3 is a structure used to seal the accommodating cavity 11. When the bare cell 2 is placed in the accommodating cavity 11, the end cap assembly 3 and the housing 12 enclose the accommodating cavity, allowing the end cap assembly 3 to seal the entrance and exit of the accommodating cavity 11, thereby preventing the bare cell 2 from escaping from the housing 12 as much as possible. In addition, the end cap assembly 3 is used to provide a location for installing the pole 4.

[0149] 1 and 2 , the end cap assembly 3 is located at one end of the housing 12 , and the poles 4 are all disposed on the end cap assembly 3 . For example, the end cap assembly 3 is located at the upper end of the housing 12 , and the poles 4 are located at the upper end of the housing 12 .

[0150] For example, referring to Figures 3 to 5 , the housing 12 is provided with end cap assemblies 3 at opposite ends along the length of the housing 12 , and each end cap assembly 3 is provided with a corresponding terminal 4. For example, the two end cap assemblies 3 are arranged in a direction that intersects the vertical direction, and the end cap assemblies 3 are not located above the housing 12 . Specifically, the terminal 4 with a positive conductive polarity is the positive terminal, and is located at one end of the length of the housing 12 , while the terminal 4 with a negative conductive polarity is the negative terminal, and is located at the other end of the length of the housing 12 .

[0151] The pole 4 electrically connected to the bare cell 2 is the main structure for the bare cell 2 to input or output electrical energy. The bare cell 2 can discharge outward through the pole 4, and an external charging device can charge the bare cell 2 through the pole 4.

[0152] Exemplarily, the pole 4 is electrically connected to the bare cell 2 via a tab.

[0153] For example, one of the poles 4 is a positive pole, and the other pole 4 is a negative pole. The positive pole is electrically connected to the positive electrode sheet via a tab, and the negative pole is electrically connected to the negative electrode sheet via a tab.

[0154] The shell 12 refers to a structure with a certain wall thickness on the outside of the battery cell. The shell 12 is mainly used to accommodate the pole core 2, provide certain protection for the pole core 2, and reduce the risk of the pole core 2 being exposed to the outside and damaged.

[0155] The width of the shell refers to the width of the shell.

[0156] In the embodiment of the present disclosure, the first wall 13 is located on the shell 12, and the position of the pressure relief structure 5 installed on the first wall 13 avoids the pole 4 installed on the end cover assembly 3. The exhaust direction of the pressure relief structure 5 is not toward the pole 4, which can reduce the damage to the insulating material of the pole 4 caused by the high-temperature gas discharged by the pressure relief structure 5 in the event of thermal runaway, thereby reducing the risk of short circuit of the battery cell.

[0157] In one embodiment, the first wall 13 may be located on the end cover assembly 3 .

[0158] In one embodiment, the housing 12 may be made of metal.

[0159] In the disclosed embodiment, metal is a relatively hard material, and the metal material of the shell 12 facilitates the protection of the bare battery cell 2 located within the shell 12. Furthermore, the shell 12 is made of metal, and the first wall 13 of the shell 12 and the raised structure 6 formed by the first wall 13 are all made of metal. Metal can withstand relatively high temperatures, and even if the raised structure 6 made of metal comes into contact with high-temperature gases generated by thermal runaway, the raised structure 6 can still separate the bare battery cell 2 from the first wall 13 to form a flow channel for fluid to flow through, thereby smoothly discharging gas in the event of thermal runaway of the battery cell.

[0160] In one embodiment, the housing 12 may be made of materials other than metal.

[0161] In one embodiment, referring to FIG. 2 and FIG. 4 to FIG. 6 , the protruding structure 6 has a weight-reducing cavity 62 . The weight-reducing cavity 62 is located on a side of the protruding structure 6 away from the accommodating cavity 11 .

[0162] The weight-reducing cavity 62 is a hollow structure, that is, the protruding structure 6 has no solid structure at the location of the weight-reducing cavity 62 .

[0163] In the embodiment of the present disclosure, the weight-reducing cavity 62 is located on the side of the raised structure 6 facing away from the accommodating cavity 11. This positioning of the weight-reducing cavity 62 does not affect the protrusion of the raised structure 6 toward the bare cell 2. Furthermore, the weight-reducing cavity 62 helps reduce the weight of the raised structure 6, thereby contributing to the lightweighting of the battery cell. Furthermore, the weight-reducing cavity 62 is located on the side of the raised structure 6 facing away from the accommodating cavity 11, allowing the raised structure 6 to be formed by stamping on the first wall 13, making the processing of the raised structure 6 relatively simple and convenient.

[0164] In one embodiment, the protruding structure 6 may not be provided with the weight-reducing cavity 62 , and the protruding structure 6 may be a solid structure.

[0165] In one embodiment, referring to FIG. 6 , the distance that the protruding structure 6 protrudes from the first wall surface 13 is greater than the distance that the protruding structure 6 protrudes from the pressure relief structure 5 .

[0166] The distance that the protruding structure 6 protrudes from the first wall surface 13 is the first dimension in the above embodiment.

[0167] The distance that the protruding structure 6 protrudes from the pressure relief mechanism 5 is a second dimension. Please refer to the figure, the second dimension is D3.

[0168] Exemplarily, referring to FIG. 6 , the first size is D1 , the second size is D3 , and D3 > D1 .

[0169] In the embodiment of the present disclosure, since the distance that the protruding structure 6 protrudes from the first wall surface 13 is greater than the distance that the protruding structure 6 protrudes from the pressure relief structure 5, the exhaust space at the pressure relief structure 5 is larger, which is conducive to the gas generated by thermal runaway to converge and discharge to the pressure relief structure 5, thereby reducing the risk of battery cell explosion.

[0170] In one embodiment, referring to FIG. 1 , the pressure relief structure 5 and the pole 4 are arranged opposite to each other. The pressure relief structure 5 is located at one end of the housing 12 , and the pole 4 is located at the other end of the housing 12 .

[0171] 1 , the pole 4 is located at the upper end of the housing 12, and the pressure relief structure 5 is located at the lower end of the housing 12. The pole 4 and the pressure relief structure 5 are arranged relative to each other in the vertical direction.

[0172] In the embodiment of the present disclosure, since the pressure relief structure 5 and the pole 4 are arranged relative to each other, the pressure relief structure 5 is located at one end of the shell 12 and the pole 4 is located at the other end of the shell 12, the direction in which the gas is discharged from the pressure relief structure 5 is almost opposite to that of the pole 4. In the event of thermal runaway, the risk of short circuit caused by the high-temperature gas discharged from the pressure relief structure 5 damaging the insulating material on the pole 4 is reduced.

[0173] The pressure relief structure 5 and the pole 4 are not limited to being arranged opposite to each other. In one embodiment, referring to FIG3 , the poles 4 at both ends of the housing 12 are arranged opposite to each other in the longitudinal direction, and the pressure relief structure 5 is adjacent to the poles 4 at both ends.

[0174] In one embodiment, referring to Figure 1 , the battery cell further comprises a support plate 7, a Mylar film 8, and an adapter plate 9. The support plate 7 is located within the housing 12 and cushioned beneath the bare cell 2. The Mylar film 8 is located within the housing 12, with the Mylar film 8 accommodating cavity 11 circumferentially surrounding the bare cell 2. The adapter plate 9 is used to electrically connect the bare cell 2 and the electrode 4, and is electrically connected to the tab of the bare cell 2. The pressure relief structure 5 is an explosion-proof valve comprising a valve body 51 and a protective film 52. The protective film 52 is affixed to the side of the valve body 51 facing away from the bare cell 2. The housing 12 is made of aluminum. The end cap assembly 3 is located above the housing 12. The end cap assembly 3 comprises a cap body 31 and a protective patch 32. The protective patch 32 covers the rear side of the cap body 31 facing away from the bare cell 2. The protective patch 32 is made of an insulating material and serves to protect the cap body 31. The first dimension is greater than or equal to 0.5 mm, the first dimension is less than or equal to 5 mm, the shape of the housing 1 is a rectangular parallelepiped, the ratio of the first dimension to the width of the housing 1 is a first ratio, the first ratio is greater than or equal to 0.01, the first ratio is less than or equal to 0.5, the unit of the first dimension is the same as the unit of the width of the housing 1, the ratio of the first dimension to the battery energy density is a second ratio, the second ratio is greater than or equal to 0.0007, the second ratio is less than or equal to 0.01, the unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, the width of the housing 1 is greater than or equal to 10, the width of the housing 1 is less than or equal to 100, the battery energy density is greater than or equal to 500, and the battery energy density is less than or equal to 1000. The weight reduction cavity 62 of the raised structure 6 is located on the side of the raised structure 6 facing away from the accommodating cavity 11. The distance that the raised structure 6 protrudes from the first wall 13 is greater than the distance that the raised structure 6 protrudes from the pressure relief structure 5. The pressure relief structure 5 and the pole 4 are arranged opposite to each other. The pressure relief structure 5 is located at one end of the housing 12 , and the pole 4 is located at the other end of the housing 12 .

[0175] Mylar film 8 refers to a film made of tough polyester polymer.

[0176] In one embodiment, referring to FIG2 , the difference from the embodiment shown in FIG1 is that end cap assemblies 3 are provided at both ends of the housing 12 in the longitudinal direction. Support plates 7 are provided above and below the bare cell 2 .

[0177] Please refer to Table 1, which shows the test results of the first size of the battery cell, the width of the shell 1 and the first ratio of the embodiment of the present disclosure. The battery energy density and the second ratio of the battery pack corresponding to each different serial number in the table are all within the corresponding value range.

[0178] Table 1

[0179] Please refer to Table 2, which shows the test results of the first size, battery energy density and second ratio of the battery cell of the embodiment of the present disclosure. The width and first ratio of the battery pack shell 1 corresponding to each different serial number in the table are all within the corresponding value range.

[0180] Table 2

[0181] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure, and they should all be included in the scope of the claims and description of the present disclosure. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present disclosure is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims. Industrial Applicability

[0182] By virtue of the protruding structure protruding toward the interior of the accommodating cavity in the embodiment of the present disclosure abutting against the bare battery cell in the accommodating cavity, a flow channel for fluid to flow through is formed between the bare battery cell and the first wall surface. The gas generated by thermal runaway of the battery cell can flow smoothly to the pressure relief structure through the flow channel and be discharged out of the outer shell through the pressure relief structure. The formation of the flow channel reduces the airflow resistance at the corner position adjacent to the flow channel in the outer shell, which is conducive to smooth exhaust, thereby reducing the risk of explosion of the battery cell.

Claims

1. A battery cell, comprising: A housing having a receiving cavity formed therein; A bare battery cell is contained in the containing cavity; A pressure relief structure, mounted on the first wall of the housing, and configured to be actuated to connect the housing chamber with an external space when the pressure or temperature in the housing chamber reaches a threshold; The first wall surface forms a protruding structure protruding toward the inside of the accommodating cavity, and the protruding structure is used to abut against the bare battery cell to form a flow channel for fluid to flow between the bare battery cell and the first wall surface.

2. The battery cell according to claim 1, wherein: The distance that the protruding structure protrudes from the first wall surface is a first dimension, and the first dimension is D1, which satisfies 0.5mm≤D1≤5mm.

3. The battery cell according to claim 2, wherein: The first dimension satisfies 2mm≤D1≤3mm.

4. The battery cell according to any one of claims 1 to 3, wherein: The shell is in the shape of a rectangular parallelepiped, the distance that the protruding structure protrudes from the first wall surface is a first dimension, the ratio of the first dimension to the width of the shell is a first ratio, the unit of the first dimension is the same as the unit of the width of the shell, and the first ratio is K1, satisfying 0.01≤K1≤0.

5.

5. The battery cell according to claim 4, wherein: The first ratio satisfies 0.2≤K1≤0.

3.

6. The battery cell according to any one of claims 1 to 5, wherein: The distance that the protruding structure protrudes from the first wall surface is a first dimension, and the ratio of the first dimension to the battery energy density is a second ratio. The unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, and the second ratio is K2, satisfying 0.0007≤K2≤0.

01.

7. The battery cell according to claim 6, wherein: The second ratio satisfies 0.001≤K2≤0.

008.

8. The battery cell according to any one of claims 1 to 7, wherein: The distance that the protruding structure protrudes from the first wall surface is a first dimension, the first dimension is D1, and satisfies 0.5mm≤D1≤5mm. The shape of the shell is a rectangular parallelepiped, the ratio of the first dimension to the width of the shell is a first ratio, the first ratio is K1, and satisfies 0.01≤K1≤0.

5. The unit of the first dimension is the same as the unit of the width of the shell. The ratio of the first dimension to the battery energy density is a second ratio, the unit of the first dimension is millimeter, the unit of the battery energy density is watt-hour / liter, the second ratio is K2, and satisfies 0.0007≤K2≤0.

01. The width of the shell is D2, and satisfies 10≤D2≤100. The battery energy density is E, and satisfies 500≤E≤1000.

9. The battery cell according to claim 8, wherein: The first dimension satisfies 2mm≤D1≤3mm, the first ratio satisfies 0.2≤K1≤0.3, the second ratio satisfies 0.001≤K2≤0.008, the width of the shell satisfies 20≤D2≤80, and the battery energy density satisfies 600≤E≤900.

10. The battery cell according to any one of claims 1 to 9, wherein: The shell includes an end cap assembly, a pole and a shell, the end cap assembly and the shell are arranged to form the accommodating cavity, the pole is installed on the end cap assembly, the pole is electrically connected to the bare battery cell, and the first wall surface is located in the shell.

11. The battery cell according to claim 10, wherein: The shell is made of metal.

12. The battery cell according to claim 10 or 11, wherein: The pressure relief structure and the pole are arranged opposite to each other. The pressure relief structure is located at one end of the shell, and the pole is located at the other end of the shell.

13. The battery cell according to any one of claims 1 to 12, wherein: The protruding structure has a weight-reducing cavity, and the weight-reducing cavity is located on a side of the protruding structure away from the accommodating cavity.

14. The battery cell according to any one of claims 1 to 13, wherein: The distance that the protruding structure protrudes from the first wall surface is greater than the distance that the protruding structure protrudes from the pressure relief structure.

15. A battery pack comprising: Box; The battery cell according to any one of claims 1 to 14, located in the box.

16. An electrical device, comprising: Device body; A power supply device for supplying power to the device body, wherein the power supply device comprises a battery cell according to any one of claims 1 to 14 or a battery pack according to claim 15.

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