Battery monomer, battery device and electric device

Abstract

The utility model relates to a battery monomer, a battery device and a power utilization device. Each battery cell comprises a shell; an end cap and an electrode assembly; wherein the shell is provided with a first side wall, and the first side wall is the side wall with the largest area in the shell; a plurality of grooves are formed in the side, facing the containing cavity, of the first side wall, all the grooves are formed at intervals in the first direction, each groove bends and extends in an arc shape in the second direction, and the first direction intersects with the second direction; each groove comprises a plurality of arc-shaped grooves, all the arc-shaped grooves are sequentially connected in the second direction, and any two adjacent arc-shaped grooves in each groove are bent reversely. Therefore, in the later period of circulation of the battery monomer, the gas can be uniformly and smoothly dispersed, the stress concentration is reduced, the first side wall is more uniformly stressed on the whole, the strength and rigidity of the shell are improved, the risk that the first side wall is deformed due to gas generation expansion of the electrode assembly is reduced, and the reliability of the battery monomer is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] The statements herein merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] At present, users have increasingly higher requirements for the energy density of batteries. In order to fully utilize the internal space of the battery cell to improve the energy density of the battery, the shell of the battery cell will be thinned and reduced in weight.

[0004] However, during the cycle of the battery cell, the internal electrode assembly will produce gas and expand, and the thinning and weight reduction treatment of the shell in the related technology will make the shell more prone to deformation, reducing the reliability of the battery cell. Utility Model Content

[0005] In view of the problem, the present application provides a battery cell, a battery device and an electrical device, which can alleviate the deformation of the shell under the action of gas production and expansion of the electrode assembly, thereby reducing the reliability problem of the battery cell.

[0006] In a first aspect, the present application provides a battery cell, comprising:

[0007] a housing having an opening on one side;

[0008] An end cover is provided at the opening and encloses the housing to form a receiving cavity;

[0009] and an electrode assembly disposed in the accommodating cavity;

[0010] The housing has a first side wall, which is the largest side wall in the housing; the first side wall has a plurality of grooves on a side facing the accommodating cavity, all of which are spaced apart from each other along a first direction, and each groove extends in an arc shape along a second direction, with the first direction intersecting the second direction;

[0011] Each groove includes a plurality of arc grooves, all of which are connected in sequence along the second direction, and any two adjacent arc grooves in each groove are bent in opposite directions.

[0012] The above-mentioned battery cell has multiple grooves on the side wall with the largest area in the shell. The multiple grooves realize the thinning and weight reduction of the shell, thereby expanding the internal space of the shell and improving the energy density of the battery cell. By arranging multiple grooves spaced from each other along the first direction, each groove extends along the second direction, so that in the later stage of the cycle, when the electrode assembly produces gas and expands, the battery cell can evenly disperse the gas through the multiple grooves. Since each groove extends in an arc shape, the gas can be dispersed more smoothly during the process of dispersing the gas, effectively reducing stress concentration, making the first side wall more evenly stressed as a whole, improving the strength and rigidity of the shell, and reducing the risk of deformation of the first side wall due to gas production and expansion of the electrode assembly, thereby improving the reliability of the battery cell.

[0013] Furthermore, by providing a plurality of arc grooves and connecting all of the arc grooves in sequence along the second direction, and by bending in the opposite direction between any two adjacent arc grooves, the overall area of ​​the grooves can be increased in the limited space in the second direction, so that the gas can be more widely dispersed in the grooves, reducing local stress concentration, and thereby reducing the risk of deformation of the shell.

[0014] In some embodiments, the second direction is parallel to a height direction of the battery cell.

[0015] When the second direction is parallel to the height direction of the battery cell, the groove can bend and extend in an arc shape parallel to the height direction of the battery cell. On the one hand, the battery cell is usually placed upright in the battery case, and the bottom wall of the battery cell is closely attached to the bottom wall of the case. Therefore, the bottom wall of the battery cell has sufficient strength. When the electrode assembly of the battery cell generates gas and expands, the gas can be dispersed and guided toward the bottom wall through the groove. Due to the sufficient strength of the bottom wall, it can resist the impact of the gas and reduce deformation of the case. On the other hand, if the groove extends in other directions, the two ends of the groove will be adjacent to the second side wall with a smaller area. In this case, the gas is dispersed and guided to the second side wall through the groove, which will be more easily deformed, reducing the reliability of the battery cell. Therefore, compared with the groove extending in other directions, the groove extending in an arc shape parallel to the height direction of the battery cell can further reduce case deformation and improve the reliability of the battery cell.

[0016] In some embodiments, the housing further has a bottom wall connected to one end of the first side wall along the second direction, and the bottom wall is arranged away from the opening; and each groove extends from one end away from the opening to the bottom wall.

[0017] When the groove extends to the bottom wall, the gas generated by the electrode assembly can be dispersed through the groove and guided to the bottom wall, so that the bottom wall can reliably resist the impact of the gas and reduce the deformation of the shell.

[0018] In some embodiments, the inner surface of the housing has a connecting portion disposed around the opening, the connecting portion being connected to the end cap;

[0019] Along the second direction, each groove is spaced apart from the connecting portion.

[0020] By arranging the intervals between each groove and the connecting portion along the second direction, the influence of the groove on the connection position between the shell and the end cover can be reduced, the reliability of the connection between the shell and the end cover can be improved, and the sealing reliability between the end cover and the shell can be improved.

[0021] In some embodiments, the housing has an open end, and the distance between each groove and the open end is 3 mm to 8 mm along the second direction.

[0022] This ensures an appropriate margin between each groove and the connection portion, improving the reliability of the connection and minimizing the impact of the groove during connection between the end cap and the housing. Furthermore, the groove can be positioned as close as possible to the opening of the housing to expand its coverage area along the second direction, increasing the area for dispersing gas generated by the electrode assembly. This reduces the risk of deformation of the first sidewall and improves the reliability of the battery cell.

[0023] In some embodiments, the arc angle of each arc groove is 25 degrees to 35 degrees.

[0024] By setting the arc angle of the arc groove to 25 degrees to 35 degrees, the arc length of the arc groove can be made shorter, so that the gas can make smaller turns in the arc groove, reducing the risk of gas rushing out of the arc groove, and allowing the gas to be more evenly dispersed in the entire arc groove.

[0025] In some embodiments, along the first direction, the distance between any two adjacent grooves is 8 mm to 10 mm.

[0026] When the spacing between two adjacent grooves is 8 mm to 10 mm, on the one hand, the shell portion between any two adjacent grooves can be improved to have sufficient rigidity and strength, and on the other hand, more grooves can be arranged as much as possible in the limited space in the second direction to achieve weight reduction and thinning of the shell.

[0027] In some embodiments, along the first direction, the width of each groove is 5 mm to 7 mm.

[0028] When the grooves are too narrow, gas entering the grooves is prone to stress concentration, causing deformation of the shell. When the grooves are too wide, the portion of the shell between the grooves lacks sufficient rigidity and strength, resulting in low rigidity and strength of the shell. Therefore, by setting the width of each groove to 5 mm to 7 mm, the groove width can be kept moderate, reducing stress concentration on the one hand and improving the rigidity and strength of the shell on the other.

[0029] In some embodiments, the thickness of the first sidewall is T, the depth of each groove is t, and the range of t is 1 / 6T to 1 / 3T.

[0030] When the groove depth t is too deep, gas tends to concentrate within the groove, causing stress concentration and easily deforming the housing. When the groove depth t is too shallow, gas tends to remain within the groove, failing to disperse the gas. This results in uneven stress on the first sidewall as a whole, reducing the strength and rigidity of the housing. However, by setting the groove depth t within a range of 1 / 6T to 1 / 3T, the embodiment of the present application reduces stress concentration and reliably disperses the gas, resulting in even stress on the first sidewall as a whole and improving the strength and rigidity of the housing.

[0031] In some embodiments, the depth t of each groove is 0.1 mm to 0.2 mm.

[0032] When the depth t of the groove is 0.1 mm to 0.2 mm, stress concentration is reduced, and the gas can be reliably dispersed, so that the first side wall is subjected to balanced stress as a whole, thereby improving the strength and rigidity of the shell.

[0033] In some embodiments, the shell includes two first side walls arranged opposite to each other, each first side wall has a plurality of grooves on a side facing the accommodating cavity, and the grooves of each first side wall are symmetrically distributed relative to the central plane of the shell.

[0034] When the grooves on each side wall are symmetrically distributed relative to the center plane of the shell, the structural balance of the shell can be improved, so that the opposite sides of the shell are evenly stressed when the electrode assembly produces gas and expands, the shell's resistance to deformation is improved, and the assembly reliability between the shell and the end cover can also be improved.

[0035] In some embodiments, a protrusion is formed between any two adjacent grooves, and the connection between the groove and the protrusion has a smooth transition.

[0036] A smooth transition between the groove and the protrusion helps to even out stress transfer and reduce stress concentration during gas production and expansion of the electrode assembly, thereby reducing the risk of shell deformation. Furthermore, the smooth transition between the groove and the protrusion can also reduce damage to the electrode assembly.

[0037] In some embodiments, the shell further includes a second side wall adjacent to the first side wall, and a surface of the second side wall facing the accommodating cavity is flat.

[0038] Since the second side wall of the shell is the stress-free wall of the battery cell, a flexible structure is usually provided on the outside to absorb the volume expansion stress or mechanical vibration energy of the battery cell during the charging and discharging process. Therefore, when the surface of the second side wall facing the accommodating cavity is flat, that is, the inner surface of the second side wall has no groove structure and protrusion structure, the second side wall can be easily deformed, reducing the risk of damage to the electrode assembly, thereby improving the reliability of the battery cell.

[0039] In a second aspect, a battery device is provided, comprising the battery cell according to any of the above embodiments.

[0040] The above-mentioned electrical device has multiple grooves on the side wall with the largest area in the shell. The multiple grooves realize the thinning and weight reduction of the shell, thereby expanding the internal space of the shell and improving the energy density of the battery cell. By arranging multiple grooves spaced from each other along the first direction, each groove extends along the second direction, so that in the later stage of the cycle, when the electrode assembly produces gas and expands, the battery cell can evenly disperse the gas through the multiple grooves. Since each groove extends in an arc shape, the gas can be dispersed more smoothly during the process of dispersing, effectively reducing stress concentration, making the first side wall more evenly stressed as a whole, improving the strength and rigidity of the shell, and reducing the risk of deformation of the first side wall due to gas production and expansion of the electrode assembly, thereby improving the reliability of the battery cell.

[0041] Furthermore, by providing a plurality of arc grooves and connecting all of the arc grooves in sequence along the second direction, and by bending in the opposite direction between any two adjacent arc grooves, the overall area of ​​the grooves can be increased in the limited space in the second direction, so that the gas can be more widely dispersed in the grooves, reducing local stress concentration, and thereby reducing the risk of deformation of the shell.

[0042] In a third aspect, an electrical device is also provided, comprising the battery device in any of the above embodiments.

[0043] The above-mentioned electrical device has multiple grooves on the side wall with the largest area in the shell. The multiple grooves realize the thinning and weight reduction of the shell, thereby expanding the internal space of the shell and improving the energy density of the battery cell. By arranging multiple grooves spaced from each other along the first direction, each groove extends along the second direction, so that in the later stage of the cycle, when the electrode assembly produces gas and expands, the battery cell can evenly disperse the gas through the multiple grooves. Since each groove extends in an arc shape, the gas can be dispersed more smoothly during the process of dispersing, effectively reducing stress concentration, making the first side wall more evenly stressed as a whole, improving the strength and rigidity of the shell, and reducing the risk of deformation of the first side wall due to gas production and expansion of the electrode assembly, thereby improving the reliability of the battery cell.

[0044] Furthermore, by providing a plurality of arc grooves and connecting all of the arc grooves in sequence along the second direction, and by bending in the opposite direction between any two adjacent arc grooves, the overall area of ​​the grooves can be increased in the limited space in the second direction, so that the gas can be more widely dispersed in the grooves, reducing local stress concentration, and thereby reducing the risk of deformation of the shell.

[0045] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] 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 application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0047] Figure 1 is a schematic structural diagram of a vehicle according to one or more embodiments.

[0048] Figure 2 is a schematic diagram of an exploded structure of a battery according to one or more embodiments.

[0049] Figure 3 is a schematic diagram of the exploded structure of a battery cell according to one or more embodiments.

[0050] Figure 4 Schematic diagram of the structure of a battery cell shell according to one or more embodiments.

[0051] Figure 5 for Figure 4 A top view of the housing is shown.

[0052] Figure 6 for Figure 5 BB cross-sectional structural diagram of the shell shown.

[0053] Figure 7 for Figure 6 An enlarged structural diagram of a part A of the shell is shown.

[0054] The accompanying drawings in the specific implementation manner are as follows:

[0055] Vehicle 1000, battery device 100, housing 10, first part 11, second part 12, battery cell 20, end cap 21, electrode terminal 211, shell 22, opening 221, electrode assembly 23, accommodating cavity 24, tab 231, first side wall 222, groove 2221, arc-shaped groove a, protrusion 2222, second side wall 223, bottom wall 224, center plane AA, controller 200, motor 300. DETAILED DESCRIPTION

[0056] The following embodiments of the technical solution of the present application will be 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 application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0057] 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 this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0058] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0059] 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 application. 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.

[0060] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, 1 and / or 2 can represent: 1 exists alone, 1 and 2 exist simultaneously, and 2 exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0061] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0062] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply 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 on the embodiments of the present application.

[0063] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," 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; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0064] Batteries, with their advantages of small size, high energy density, long service life, and environmental friendliness, are widely used in industries such as automobiles, electronics, and energy storage systems. Batteries are typically composed of multiple cells. Currently, to increase battery energy, technologies are being proposed to reduce the thickness and weight of the cell casing to expand the internal volume of the cell.

[0065] The shell of the battery cell can be thinned and reduced in weight by providing a groove on the inner wall of the shell. The provision of the groove not only reduces the material usage of the shell and reduces the weight of the shell, but also, because the groove is provided facing the interior of the shell, it can expand the internal space of the shell, thereby allowing more active materials (such as positive and negative electrode materials and electrolyte) to be loaded, thereby increasing the energy density of the battery cell.

[0066] However, as the internal space of the battery cell shell is fully utilized, the internal electrode assembly of the battery cell will produce gas and expand during the cycle. This expansion force will be applied to the wall of the shell. The grooves on the shell that have been thinned and reduced in weight will cause gas to accumulate in the grooves and form stress concentration points, making the shell more prone to deformation, affecting the normal use of the battery cell and reducing the reliability of the battery cell.

[0067] In order to alleviate the problem of reduced reliability of the battery cell due to deformation of the shell under the action of gas production and expansion of the electrode assembly, the present application designs a battery cell, including a shell, an end cover and an electrode assembly. One side of the shell has an opening, and the end cover is arranged at the opening and enclosed with the shell to form a accommodating cavity, and the electrode assembly is arranged in the accommodating cavity. Among them, the shell has a first side wall, which is the side wall with the largest area in the shell. The first side wall has a plurality of grooves on the side facing the accommodating cavity. All grooves are arranged at intervals from each other along the first direction, and each groove is curved and extended in an arc shape along the second direction, and the first direction intersects the second direction. Each groove includes a plurality of arc grooves, all of which are connected in sequence along the second direction, and any two adjacent arc grooves in each groove are bent in opposite directions.

[0068] In this way, since multiple grooves are provided on the side wall with the largest area in the shell, the multiple grooves realize the thinning and weight reduction of the shell, thereby expanding the internal space of the shell and improving the energy density of the battery cell. By providing multiple grooves spaced apart from each other along the first direction, each groove extends along the second direction, so that in the later stage of the cycle, when the electrode assembly produces gas and expands, the battery cell can evenly disperse the gas through the multiple grooves. Moreover, since each groove extends in an arc shape, the gas can be dispersed more smoothly during the process of dispersing the gas, effectively reducing stress concentration, making the first side wall more evenly stressed as a whole, improving the strength and rigidity of the shell, and reducing the risk of deformation of the first side wall due to gas production and expansion of the electrode assembly, thereby improving the reliability of the battery cell.

[0069] Furthermore, by providing a plurality of arc grooves and connecting all of the arc grooves in sequence along the second direction, and by bending in the opposite direction between any two adjacent arc grooves, the overall area of ​​the grooves can be increased in the limited space in the second direction, so that the gas can be more widely dispersed in the grooves, reducing local stress concentration, and thereby reducing the risk of deformation of the shell.

[0070] The battery cell of the present application is applied to a battery to alleviate the problem that the shell is deformed due to the expansion of gas generated by the electrode assembly, thereby reducing the reliability of the battery cell.

[0071] The battery disclosed in the embodiments of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft.

[0072] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0073] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0074] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 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 device 100 is provided inside the vehicle 1000. The battery device 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 may be used to power the vehicle 1000. For example, the battery device 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and operating power requirements of the vehicle 1000 during driving.

[0075] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0076] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of the present application. The battery device 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 can include a first portion 11 and a second portion 12, which overlap each other and together define a storage space for the battery cell 20. The second portion 12 can be a hollow structure with one end open. The first portion 11 can be a plate-like structure, with the first portion 11 overlapping the open side of the second portion 12, so that the first portion 11 and the second portion 12 together define a storage space. The first portion 11 and the second portion 12 can also be hollow structures with one end open, with the open side of the first portion 11 overlapping the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0077] In the battery device 100, there may be multiple battery cells 20, which may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery unit 20 may be housed within the housing 10. Alternatively, the battery device 100 may comprise multiple battery cells 20 connected in series, in parallel, or in a hybrid connection to form a battery module, which is then further connected in series, in parallel, or in a hybrid connection to form a single unit and housed within the housing 10. The battery device 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0078] Each battery cell 20 may be a secondary battery or a primary battery, and may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0079] Please refer to Figure 3 , Figure 3 The following is a schematic diagram of the decomposition structure of a battery cell 20 provided in some embodiments of the present application. A battery cell 20 is the smallest unit that makes up a battery. Figure 3 The battery cell 20 includes an end cap 21, a shell 22, an electrode assembly 23 and other functional components.

[0080] The end cap 21 is a component that covers the opening 221 of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cap 21 can be made of a material with a certain degree of hardness and strength (such as an aluminum alloy). This prevents the end cap 21 from deforming under pressure or collision, thereby enhancing the structural strength and safety of the battery cell 20. The end cap 21 can be provided with functional components such as electrode terminals 211. The electrode terminals 211 can be used to electrically connect to the electrode assembly 23 to transmit or receive electrical energy from the battery cell 20. In some embodiments, the end cap 21 can also be provided with a pressure relief mechanism to release internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 21 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, and this is not particularly limited in the present embodiment. In some embodiments, an insulating member may be provided inside the end cap 21 to isolate the electrical connection components in the housing 22 from the end cap 21 to reduce the risk of short circuit. For example, the insulating member may be made of plastic, rubber, or the like.

[0081] The housing 22 is a component that cooperates with the end cap 21 to form the internal environment of the battery cell 20. This internal environment can be used to accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and end cap 21 can be separate components. An opening can be provided in the housing 22, and the end cap 21 is placed over the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 21 and housing 22 can be integrated. Specifically, the end cap 21 and housing 22 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 22 needs to be enclosed, the end cap 21 is placed over the housing 22. The housing 22 can have a variety of shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. Specifically, the shape of the housing 22 can be determined based on the specific shape and size of the electrode assembly 23. The housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0082] The electrode assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs. One or more electrode assemblies 23 may be contained within the housing 22. The electrode assembly 23 is primarily composed of positive and negative electrode materials, a separator, and a current collector. Specifically, the positive electrode material is coated on the battery output connector to form a positive electrode sheet, and the negative electrode material is coated on the battery output connector to form a negative electrode sheet. The positive and negative electrode sheets are wound or stacked, and the separator is disposed between the positive and negative electrode sheets to form the electrode assembly 23. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 23, while the portions of the positive and negative electrode sheets without active material each constitute a tab 231. The positive and negative electrode tabs may be located together at one end of the main body or separately at both ends of the main body. During the battery's charge and discharge process, the positive and negative electrode active materials react with the electrolyte, and the tabs 231 connect to the electrode terminals 211 to form a current circuit.

[0083] See attached Figures 4 to 6 , an embodiment of the present application provides a battery cell 20, including an end cover 21, a shell 22 and an electrode assembly 23. One side of the shell 22 has an opening 221, and the end cover 21 is covered at the opening 221 and enclosed with the shell 22 to form a accommodating cavity 24. The electrode assembly 23 is arranged in the accommodating cavity 24. Among them, the shell 22 has a first side wall 222, and the first side wall 222 is the side wall with the largest area in the shell 22. The first side wall 222 has a plurality of grooves 2221 on the side facing the accommodating cavity 24. All grooves 2221 are arranged to be spaced apart from each other along the first direction, and each groove 2221 is curved and extended in an arc shape along the second direction, and the first direction intersects with the second direction. Each groove 2221 includes a plurality of arc grooves a, and all arc grooves a are connected in sequence along the second direction. Any two adjacent arc grooves a in each groove 2221 are bent in opposite directions.

[0084] The housing 22 may include multiple side walls. For example, when the battery cell 20 is a square battery, the housing 22 includes four side walls. Among the four side walls, two side walls arranged opposite to each other in the thickness direction have the largest area.

[0085] The groove 2221 refers to a groove structure formed by being recessed relative to the inner surface of the first side wall 222. Specifically, the groove 2221 can be formed by stamping the first side wall 222, or by milling or directly by die forming.

[0086] The first direction mentioned above can specifically be Figure 4 The X direction shown, the second direction can be perpendicular to the first direction, specifically can be Figure 4 The Z direction is shown.

[0087] All the grooves 2221 are spaced apart from each other along the first direction, which means that all the grooves 2221 are arranged along the first direction, and there is a certain distance between any two adjacent grooves 2221 , and a protrusion is formed at the interval.

[0088] The groove 2221 extends in an arc shape along the second direction, which means that the groove 2221 is not a straight line in the path extending along the second direction, but is curved, and the curved shape is an arc, which can be a circular arc or an elliptical arc.

[0089] The arc groove a refers to a groove structure that is arc-shaped when viewed along the depth direction of the groove. The shape of the arc groove a can be a circular arc or an elliptical arc.

[0090] When all the arc-shaped grooves a are sequentially connected along the second direction, it means that all the arc-shaped grooves a are arranged along the second direction, and ends of any two adjacent arc-shaped grooves a are connected to each other.

[0091] Any two adjacent arc-shaped grooves a are bent in opposite directions, so that a shape similar to the letter "S" is formed between any two arc-shaped grooves a.

[0092] It should be noted that the shape of each arcuate groove a can be the same or different. In addition, the number of the arcuate grooves a can be greater than three, for example, four, five or six, or of course, two.

[0093] In this way, since multiple grooves 2221 are provided on the side wall with the largest area in the shell 22, the multiple grooves 2221 realize the thinning and weight reduction of the shell 22, thereby expanding the internal space of the shell 22 and improving the energy density of the battery cell 20. By providing multiple grooves 2221 spaced from each other along the first direction, each groove 2221 extends along the second direction, so that in the later stage of the cycle, when the electrode assembly 23 produces gas and expands, the battery cell 20 can evenly disperse the gas through the multiple grooves 2221, and since each groove 2221 is curved and extended in an arc shape, the gas can be dispersed more smoothly during the process of dispersing the gas, effectively reducing stress concentration, making the first side wall 222 more evenly stressed as a whole, improving the strength and rigidity of the shell 22, and reducing the risk of deformation of the first side wall 222 due to gas production and expansion of the electrode assembly 23, thereby improving the reliability of the battery cell 20.

[0094] Furthermore, by providing a plurality of arc grooves a and connecting all of the arc grooves a in sequence along the second direction, and by bending in the opposite direction between any two adjacent arc grooves a, the overall area of ​​the groove 2221 can be increased in the limited space in the second direction, so that the gas can be more widely dispersed in the groove 2221, reducing the situation of local stress concentration, thereby reducing the risk of deformation of the shell 22.

[0095] According to some embodiments of the present application, the second direction is parallel to the height direction of the battery cell 20 .

[0096] When the second direction is parallel to the height direction of the battery cell 20, the groove 2221 can be bent and extended in an arc shape parallel to the height direction of the battery cell 20. On the one hand, the battery cell 20 is usually placed upright in the box 10 of the battery device 100, and the bottom wall of the battery cell 20 is close to the bottom wall of the box 10. Therefore, the bottom wall of the battery cell 20 has sufficient strength. When the electrode assembly 23 of the battery cell 20 generates gas and expands, the gas can be dispersed and guided to the bottom wall 224 through the groove 2221. Since the bottom wall 224 is strong enough, it can resist the impact of the gas and reduce the deformation of the shell 22. On the other hand, if the groove 2221 extends in other directions, the two ends of the groove 2221 will be adjacent to the second side wall 223 with a smaller area. At this time, the gas is dispersed and guided to the second side wall 223 through the groove 2221. The second side wall 223 will be more easily deformed, which reduces the reliability of the battery cell 20. Therefore, compared with the groove 2221 extending in other directions, the groove 2221 extends in an arc shape along a height direction parallel to the battery cell 20 , which can further reduce the deformation of the housing 22 and improve the reliability of the battery cell 20 .

[0097] See Figure 6According to some embodiments of the present application, the housing 22 further includes a bottom wall 224 connected to one end of the first side wall 222 along the second direction, and the bottom wall 224 is disposed away from the opening 221. One end of each groove 2221 away from the opening 221 extends to the bottom wall 224.

[0098] When the groove 2221 extends to the bottom wall 224 , the gas generated by the electrode assembly 23 can be dispersed through the groove 2221 and guided to the bottom wall 224 , so that the bottom wall 224 can reliably resist the impact of the gas and reduce deformation of the shell 22 .

[0099] In some other embodiments, along the second direction, each groove 2221 may be spaced a certain distance from the bottom wall 224. However, the gas generally disperses toward the bottom wall 224, so the bottom wall 224 can still resist some gas impacts.

[0100] According to some embodiments of the present application, the inner surface of the shell 22 has a connecting portion arranged around the opening 221, the connecting portion is connected to the end cover 21, and along the second direction, each groove 2221 is spaced apart from the connecting portion.

[0101] The connection portion is the portion of the housing 22 that connects to the end cap 21 after the opening 221 of the housing 22 receives the end cap 21. The formation of the connection portion can be determined by the connection method between the housing 22 and the end cap 21. For example, when the housing 22 and the end cap 21 are laser welded, the connection portion is the portion where the housing 22 and the end cap 21 are connected together after the laser welding.

[0102] Along the second direction, each groove 2221 is spaced apart from the connecting portion, which means that along the second direction, one end of each groove 2221 facing the end cover 21 is spaced apart from the connecting portion by a certain distance.

[0103] Therefore, by arranging the intervals between each groove 2221 and the connecting portion along the second direction, the influence of the groove 2221 on the connection position between the shell 22 and the end cover 21 can be reduced, the reliability of the connection between the shell 22 and the end cover 21 can be improved, and the sealing reliability between the end cover 21 and the shell 22 can be improved.

[0104] Combine Figure 7 Specifically, one end of the shell 22 having the opening 221 is the open end, and along the second direction, the spacing distance L1 between each groove 2221 and the open end is 3 mm to 8 mm.

[0105] In this way, an appropriate spacing margin can be provided between each groove 2221 and the connection portion, thereby improving the reliability of the connection portion and reducing the impact of the groove 2221 during the connection process between the end cap 21 and the housing 22. In addition, the groove 2221 can be as close as possible to the opening 221 of the housing 22, thereby expanding the coverage area of ​​the groove 2221 along the second direction and expanding the area for dispersing the gas generated by the electrode assembly 23, thereby reducing the risk of deformation of the first side wall 222 and improving the reliability of the battery cell 20.

[0106] See Figure 6 According to some embodiments of the present application, the arc angle R of each arc groove a is 25 degrees to 35 degrees.

[0107] The arc angle R of the arc groove a refers to the angle formed by the line connecting the two end points of the arc of the arc groove a and the center of the circle.

[0108] By setting the arc angle of the arc groove a to 25 degrees to 35 degrees, the arc length of the arc groove a can be made smaller, so that the gas can make a smaller turn in the arc groove a, reducing the risk of the gas rushing out of the arc groove a, and allowing the gas to be more evenly dispersed in the entire arc groove a.

[0109] Combine Figure 7 According to some embodiments of the present application, along the first direction, the distance L2 between any two adjacent grooves 2221 is 8 mm to 10 mm.

[0110] When the spacing L2 between two adjacent grooves 2221 is 8 mm to 10 mm, on the one hand, the rigidity and strength of the shell 22 between any two adjacent grooves 2221 can be improved, and on the other hand, more grooves 2221 can be arranged in the limited space in the second direction as much as possible to achieve weight reduction and thinning of the shell 22.

[0111] According to some embodiments of the present application, along the first direction, a width L3 of each groove 2221 is 5 mm to 7 mm.

[0112] If the grooves 2221 are too narrow, stress concentration may occur after gas enters the grooves 2221, causing deformation of the housing 22. If the grooves 2221 are too wide, the portion of the housing 22 between the grooves 2221 lacks sufficient rigidity and strength, resulting in low rigidity and strength of the housing 22. Therefore, by setting the width L3 of each groove 2221 to 5 mm to 7 mm, the width L3 of the grooves 2221 can be adjusted to a moderate value, thereby reducing stress concentration and improving the rigidity and strength of the housing 22.

[0113] According to some embodiments of the present application, the thickness of the first sidewall 2221 is T, the depth of each groove 2221 is t, and the range of t is 1 / 6T~1 / 3T.

[0114] When the depth t of the groove 2221 is too deep, gas tends to concentrate within the groove 2221, causing stress concentration and easily deforming the housing 22. When the depth t of the groove 2221 is too shallow, gas tends to remain within the groove 2221, failing to disperse the gas. This results in uneven stress on the first sidewall 222 as a whole, reducing the strength and rigidity of the housing 22. However, in the embodiment of the present application, by setting the depth t of the groove 2221 to a range of 1 / 6T to 1 / 3T, stress concentration is reduced, gas can be reliably dispersed, and the overall stress on the first sidewall 222 is balanced, thereby improving the strength and rigidity of the housing 22.

[0115] Specifically, the depth t of each groove 2221 is 0.1 mm to 0.2 mm.

[0116] When the depth t of the groove 2221 is 0.1 mm to 0.2 mm, stress concentration is reduced, and the gas can be reliably dispersed, so that the first side wall 222 is subjected to balanced stress as a whole, thereby improving the strength and rigidity of the shell 22.

[0117] Combine 4 and Figure 5 According to some embodiments of the present application, the shell 22 includes two first side walls 222 arranged opposite to each other, and each first side wall 222 has a plurality of grooves 2221 on the side facing the accommodating cavity 24, and the grooves 2221 of each side wall 222 are symmetrically distributed relative to the center plane AA of the shell 22.

[0118] The center plane AA of the shell 22 specifically refers to the center plane of the shell 22 along the relative direction of the two first side walls 222. The relative direction of the two first side walls 222 referred to here is specifically Figure 4 The Y direction shown is the thickness direction of the battery cell 20 .

[0119] When the grooves 2221 of each side wall 222 are symmetrically distributed relative to the center plane AA of the shell 22, the structural balance of the shell 22 can be improved, so that the opposite sides of the shell 22 are evenly stressed when the electrode assembly 23 produces gas and expands, thereby improving the deformation resistance of the shell 22 and improving the assembly reliability between the shell 22 and the end cover 21.

[0120] According to some embodiments of the present application, a protrusion 2222 is formed between any two adjacent grooves 2221 , and the connection between the groove 2221 and the protrusion 2222 has a smooth transition.

[0121] The smooth transition between the groove 2221 and the protrusion 2222 means that the connection between the groove 2221 and the protrusion 2222 is flat and smooth. The smooth transition can be achieved by setting a rounded corner, a chamfered corner, or a gradient curve.

[0122] A smooth transition between the groove 2221 and the protrusion 2222 helps to balance stress transfer and reduce stress concentration during the gas production and expansion of the electrode assembly 23, thereby reducing the risk of deformation of the housing 22. In addition, the smooth transition design between the groove 2221 and the protrusion 2222 can also reduce damage to the electrode assembly 23.

[0123] See Figure 4 According to some embodiments of the present application, the shell 22 further includes a second side wall 223 adjacent to the first side wall 222 , and a surface of the second side wall 223 facing the accommodating cavity 24 is a plane.

[0124] Since the second side wall 223 of the shell 22 is the stress-free wall of the battery cell 20, a flexible structure is usually provided on the outside to absorb the volume expansion stress or mechanical vibration energy of the battery cell 20 during the charging and discharging process. When the surface of the second side wall 223 facing the accommodating cavity 24 is flat, that is, the inner surface of the second side wall 223 has no groove structure and protrusion structure, the second side wall 223 can be easily deformed, reducing the risk of damage to the electrode assembly 23, thereby improving the reliability of the battery cell 20.

[0125] According to some embodiments of the present application, the housing 22 is an aluminum alloy housing.

[0126] Aluminum alloy shell refers to a shell made of aluminum alloy material.

[0127] When the shell 22 of the embodiment of the present application adopts an aluminum alloy shell, on the one hand, the aluminum alloy has a low density, which can reduce the weight of the shell 22 and improve the battery energy density, and also has the advantages of high heat dissipation efficiency and corrosion resistance; on the other hand, aluminum alloy can be formed into complex patterns through processes such as extrusion. Therefore, when the present application forms a groove 2221 on the shell 22 that is curved and extended in an arc shape along the second direction, it can be easier to form and can take into account the requirements of light weight and strength.

[0128] According to some embodiments of the present application, the material elongation of the aluminum alloy shell is not less than 10%.

[0129] The aluminum alloy shell needs to have sufficient strength to withstand the pressure changes inside the shell 22 and external mechanical stress. Good elongation can improve the forming performance of the material and reduce the possibility of cracks during the stamping process. Therefore, when the material elongation of the aluminum alloy shell is not less than 10%, the plasticity of the material can be improved and the risk of brittle fracture can be reduced.

[0130] According to some embodiments of the present application, referring to Figures 1 to 6 , provides a battery device 100, including the battery cell 20 in any of the above embodiments.

[0131] The battery device 100 of the embodiment of the present application has multiple grooves 2221 set on the side wall with the largest area in the shell 22. The multiple grooves 2221 achieve thinning and weight reduction of the shell 22, thereby expanding the internal space of the shell 22 and improving the energy density of the battery cell 20. By setting multiple grooves 2221 spaced from each other along the first direction, each groove 2221 extends along the second direction, so that the battery cell 20 can evenly disperse the gas through the multiple grooves 2221 during the gas generation and expansion process of the electrode assembly 23 in the late cycle. Since each groove 2221 is curved and extended in an arc shape, the gas can be dispersed more smoothly during the process, effectively reducing stress concentration, making the first side wall 222 more evenly stressed as a whole, improving the strength and rigidity of the shell 22, and reducing the risk of deformation of the first side wall 222 due to gas generation and expansion of the electrode assembly 23, thereby improving the reliability of the battery cell 20.

[0132] In addition, an embodiment of the present application further provides an electrical device, comprising the battery device 100 in any of the above embodiments.

[0133] The electrical device of the embodiment of the present application has multiple grooves 2221 set on the side wall with the largest area in the shell 22. The multiple grooves 2221 achieve thinning and weight reduction of the shell 22, thereby expanding the internal space of the shell 22 and improving the energy density of the battery cell 20. By setting multiple grooves 2221 spaced from each other along the first direction, each groove 2221 extends along the second direction, so that the battery cell 20 can evenly disperse the gas through the multiple grooves 2221 during the gas production and expansion of the electrode assembly 23 in the later stage of the cycle. Since each groove 2221 is curved and extended in an arc shape, the gas can be dispersed more smoothly during the process, effectively reducing stress concentration, making the first side wall 222 more evenly stressed as a whole, improving the strength and rigidity of the shell 22, and reducing the risk of deformation of the first side wall 222 due to gas production and expansion of the electrode assembly 23, thereby improving the reliability of the battery cell 20.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application 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 application, and they should all be included in the scope of the claims and specification of the present application. 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 application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing having an opening on one side; An end cover is provided at the opening and enclosed with the shell to form a receiving cavity; as well as an electrode assembly, disposed in the accommodating cavity; The housing has a first side wall, which is the side wall with the largest area in the housing; the first side wall has a plurality of grooves on a side facing the accommodating cavity, all of the grooves are spaced apart from each other along a first direction, and each of the grooves extends in an arc shape along a second direction, and the first direction intersects the second direction; Each of the grooves includes a plurality of arc-shaped grooves, all of which are sequentially connected along the second direction, and any two adjacent arc-shaped grooves in each groove are bent in opposite directions.

2. The battery cell according to claim 1, wherein: The second direction is parallel to a height direction of the battery cell.

3. The battery cell according to claim 2, characterized in that: The shell further has a bottom wall connected to one end of the first side wall along the second direction, and the bottom wall is arranged away from the opening; and one end of each groove away from the opening extends to the bottom wall.

4. The battery cell according to claim 2, characterized in that The inner surface of the shell has a connecting portion arranged around the opening, and the connecting portion is connected to the end cover; Along the second direction, each of the grooves is spaced apart from the connecting portion.

5. The battery cell according to claim 4, characterized in that One end of the shell having the opening is the open end, and along the second direction, a distance between each of the grooves and the open end is 3 mm to 8 mm.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The arc angle of each arc-shaped groove is 25 degrees to 35 degrees.

7. The battery cell according to any one of claims 1 to 5, characterized in that: Along the first direction, the distance between any two adjacent grooves is 8 mm to 10 mm.

8. The battery cell according to any one of claims 1 to 5, characterized in that: Along the first direction, the width of each of the grooves is 5 mm to 7 mm.

9. The battery cell according to any one of claims 1 to 5, characterized in that: The thickness of the first sidewall is T, the depth of each groove is t, and the range of t is 1 / 6T~1 / 3T.

10. The battery cell according to claim 9, characterized in that The depth t of each groove is 0.1 mm to 0.2 mm.

11. The battery cell according to any one of claims 1 to 5, characterized in that: The shell includes two first side walls arranged opposite to each other. Each first side wall has a plurality of grooves on a side facing the accommodating cavity, and the grooves of each first side wall are symmetrically distributed relative to the central plane of the shell.

12. The battery cell according to any one of claims 1 to 5, characterized in that: A bulge is formed between any two adjacent grooves, and the connection between the groove and the bulge is smoothly transitioned.

13. The battery cell according to any one of claims 1 to 5, characterized in that: The housing further includes a second side wall adjacent to the first side wall, and a surface of the second side wall facing the accommodating cavity is a plane.

14. A battery device, characterized in that: The invention comprises a battery cell according to any one of claims 1 to 13.

15. An electrical device, characterized in that: Comprising the battery device of claim 14.

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