Battery monomer, battery device and electric equipment

Abstract

The utility model relates to a battery monomer, a battery device and electric equipment, a buffer structure is arranged on the surface of a corner part, and when an electrode assembly expands, if the buffer structure is in buffer butt joint between the corner part and a battery shell in the first direction, expansion of the corner part in the first direction can be directly limited; if the buffer structure is abutted between the corner part and the battery shell along the thickness direction of the electrode assembly, the corner part can be prevented from moving along the first direction by utilizing the friction between the buffer structure and the inner wall of the battery shell; meanwhile, the probability of direct friction between the corner part and the inner wall of the battery shell can be reduced; when the buffer structure is abutted between the two adjacent electrode assemblies, a buffer space can be provided between the two adjacent electrode assemblies, and the probability of stress concentration caused by direct contact of the two electrode assemblies at the corner part is reduced. According to the design, the cracking probability of the electrode assembly at the corner part can be effectively reduced, and the reliability of the battery device can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to battery cells, battery devices and electrical equipment. Background Technology

[0002] With the rapid development of battery technology, the requirements for battery reliability are also increasing. During battery use, the active layer of the electrodes expands, increasing the overall volume of the battery's electrode assembly. However, due to the structural design limitations of traditional battery cells, there is a risk of cracking at corners as the battery continues to be used, affecting its reliability. Utility Model Content

[0003] Therefore, it is necessary to provide a battery cell, battery device, and electrical equipment that can reduce the probability of cracking at the corners of the electrode assembly, thereby improving the reliability of the battery device.

[0004] In a first aspect, this application provides a battery cell, which includes: a battery casing; an electrode assembly housed within the battery casing, and the electrode assembly includes a straight portion and two corner portions respectively disposed at both ends of the straight portion along a first direction, the first direction intersecting the thickness direction of the electrode assembly; wherein the battery cell further includes a buffer structure, the buffer structure protruding from the surface of at least one corner portion.

[0005] The aforementioned battery cell features a buffer structure on its corner surface. When the electrode assembly expands, if the buffer structure abuts against the corner and the battery casing along a first direction, it directly restricts the corner's expansion in that direction. If the buffer structure abuts against the corner and the battery casing along the thickness direction of the electrode assembly, the friction between the buffer structure and the inner wall of the battery casing hinders the corner's movement along the first direction, reducing the likelihood of direct friction between the corner and the inner wall of the battery casing. If the buffer structure abuts between two adjacent electrode assemblies, it provides a buffer space, reducing the likelihood of stress concentration due to direct contact at the corner. This design effectively reduces the probability of cracking at the corner of the electrode assembly, thus improving the reliability of the battery device.

[0006] In some embodiments, at least a portion of the buffer structure is disposed on at least one side of the electrode assembly along its thickness direction, and includes a first buffer member that protrudes from the corner portion on one side along the thickness direction of the electrode assembly. This design, with the first buffer member disposed on at least one side of the corner portion along the thickness direction of the electrode assembly, can reduce outward wear caused by friction from the top shell at the corner portion, or limit the force concentration caused by direct compression between adjacent corner portions, effectively reducing the probability of cracking of the electrode assembly at the corner portion and improving the reliability of the battery device.

[0007] In some embodiments, a junction end is formed at the junction between the straight portion and the corner portion, and the first buffer extends along a first direction to or beyond the junction end adjacent to itself. This design, extending the first buffer to or beyond the junction end, can effectively buffer and protect the junction end, reduce the risk of stress concentration at the junction end, improve structural strength, and thus reduce the probability of cracking at the junction end due to expansion.

[0008] In some embodiments, the buffer structure located on one side of the electrode assembly along its thickness direction includes two first buffer members, which are respectively disposed at the two corner portions. This design, with the first buffer members disposed at the two corner portions, can prevent the corner portions from moving along the first direction during expansion, reducing the outward extension consumption of the corner portions, lowering the probability of cracking at the corner portions during expansion, and improving the reliability of the battery device.

[0009] In some embodiments, the buffer structure located on one side of the electrode assembly along its thickness direction further includes a first connector, which connects the two first buffer components. This design, by introducing the first connector, makes the two first buffer components form an integral structure. This increases the friction between the buffer structure and the battery casing, reducing wear from outward extension at the corner; alternatively, it can reduce the possibility of direct compression between the two electrode assemblies, thereby reducing stress concentration at the corner and improving structural stability.

[0010] In some embodiments, the dimensions of each first buffer member along the second direction are larger than the dimensions of the first connector along the second direction, wherein the first direction, the second direction, and the thickness direction of the electrode assembly intersect each other and are not coplanar. This design can relatively increase the buffer area at corners, improving the protective effect; at the same time, it can relatively reduce the space occupied on straight sections and save material used in the buffer structure on straight sections.

[0011] In some embodiments, the dimension of the first buffer member along the first direction is denoted as W1, and the dimension of the battery casing along the first direction is denoted as W0, wherein 5% ≤ W1 / W0 ≤ 50%. This design controls the ratio between dimensions W1 and W0 to between 5% and 50%, increasing the protection range at corners while controlling the reasonable space occupied by the first buffer member within the battery casing, thereby improving the cushioning protection at corners and reducing the probability of cracking at corners.

[0012] In some embodiments, the electrode assembly includes multiple electrode assemblies, at least some of which are stacked sequentially along their respective thickness directions. In the thickness direction of the electrode assemblies, at least one buffer structure is provided between adjacent electrode assemblies and between the electrode assembly and the battery casing. This design, by providing buffer structures between the electrode assembly and the battery casing and / or between adjacent electrode assemblies, effectively buffers the load, reduces stress concentration at corners, lowers the probability of cracking at corners, and improves the reliability of the battery device.

[0013] In some embodiments, at least a portion of the buffer structure is disposed on at least one side of the electrode assembly along the first direction, and includes a second buffer member that protrudes from the corner portion on one side along the first direction. This design, with the second buffer member disposed on at least one side of the corner portion along the first direction, effectively buffers the expansion of the corner portion along the first direction; simultaneously, the friction between the second buffer member and the inner wall of the battery casing reduces the expansion of the electrode assembly along the thickness direction, which is beneficial for improving the structural stability of the electrode assembly.

[0014] In some embodiments, the electrode assembly includes multiple electrode assemblies, with at least some of the electrode assemblies stacked sequentially along their respective thickness directions. A buffer structure located on one side of the electrode assembly along the first direction includes multiple second buffer members, each second buffer member protruding from the corresponding corner portion along the first direction. This design, with second buffer members at each corner portion, reduces the expansion of the corner portion along the first direction, effectively buffering the stress concentration at the corner portion, lowering the probability of cracking at the corner portion, and improving the reliability of the battery device.

[0015] In some embodiments, the buffer structure located on one side of the electrode assembly along the first direction further includes a second connector. At least two adjacent second buffers on one side of the electrode assembly along the first direction are connected by a second connector. This design, by introducing the second connector, makes the two second buffers form an integral structure, which restricts the expansion of the corner portion along the first direction; it also increases the friction between the buffer structure and the battery casing, reduces the movement of the corner portion along the thickness direction, lowers the probability of corner portion cracking, and improves the stability of the structure.

[0016] In some embodiments, the dimensions of two adjacent second buffer members along the second direction are both larger than the dimensions of the second connector along the second direction, wherein the first direction, the second direction, and the thickness direction of the electrode assembly intersect each other and are not coplanar. This design can relatively increase the buffer area at the corner, improving the protective effect; at the same time, it can relatively reduce the space occupied on the electrode assembly side and save material on the buffer structure on the electrode assembly side.

[0017] In some embodiments, the dimension of the second buffer member along the thickness direction of the electrode assembly is denoted as L1, and the dimension of the battery casing along the thickness direction of the electrode assembly is denoted as L0, wherein 5% ≤ L1 / L0 ≤ 50%. This design controls the ratio between dimensions L1 and L0 to between 5% and 50%, improving the buffer protection of corners and reducing the probability of cracking at corners while controlling the reasonable space occupied by the first buffer member within the battery casing.

[0018] In some embodiments, the thickness of the buffer structure is denoted as H1, and the thickness of the electrode assembly is denoted as H0, wherein 1% ≤ H1 / H0 ≤ 15%. This design controls the ratio between dimensions H1 and H0 to between 1% and 15%, thereby improving the buffer protection of corners and reducing the probability of cracking at corners while controlling the reasonable space occupied by the first buffer component within the battery casing.

[0019] In some embodiments, the buffer structure is configured to have elastic compression, and the compression ratio of the buffer structure is greater than or equal to 75%. This design, with a compression ratio of greater than or equal to 75%, improves the buffering effect of the buffer structure, effectively reduces the probability of cracking at the corners, and improves the reliability of the battery device.

[0020] In some embodiments, the buffer structure is configured as a resiliently compressible and porous structure. This design, while providing effective buffering protection, reduces the impact of wetting or heat dissipation on the electrode components, further improving the reliability of the battery device.

[0021] Secondly, this application provides a battery device, which includes any of the above-mentioned battery cells.

[0022] Thirdly, this application provides an electrical device that includes the battery device described above. Attached Figure Description

[0023] Figure 1 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0024] Figure 2 The diagram shows the structure of a vehicle provided in some embodiments of this application.

[0025] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0026] Figure 4 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 1 .

[0027] Figure 5 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 2 .

[0028] Figure 6 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 3 .

[0029] Figure 7 This is a schematic diagram illustrating the structure of the buffer structure and electrode assembly provided in some embodiments of this application.

[0030] Figure 8 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 4 .

[0031] Figure 9 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 5 .

[0032] Figure 10 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 6 .

[0033] Figure 11 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 7 .

[0034] Figure 12 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 8 .

[0035] Figure 13 Schematic diagram of the structure of a battery cell provided in some embodiments of this application Figure 9 .

[0036] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 10, Battery Cell; 20, Housing; 201, First Part; 202, Second Part; 1, Battery Casing; 11, End Cap; 12, Housing; 121, Opening; 2, Electrode Assembly; 21, Straight Section; 22, Corner Section; 23, Junction End; 3, Buffer Structure; 31, First Buffer Component; 32, First Connector; 33, Second Buffer Component; 34, Second Connector; X, First Direction; Y, Second Direction; Z, Thickness Direction. Detailed Implementation

[0037] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0038] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0039] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0040] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0043] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0044] The battery assembly includes individual battery cells. During cyclic charging and discharging, the active layer of the electrode plates expands, causing the overall volume of the electrode assembly to increase, thus bringing the electrode assembly into contact with the inner wall of the battery casing. As the expansion continues, the expansion force can cause the corners of the electrode assembly to move laterally or the corners of two adjacent electrode assemblies to squeeze against each other, resulting in stress concentration at the corners and making them prone to cracking.

[0045] Based on this, addressing the risk of cracking at the corners of electrode assemblies in traditional battery cells, this application provides a battery cell with a buffer structure on the surface of the corner. When the electrode assembly expands, if the buffer structure abuts against the corner and the battery casing along a first direction, it can directly limit the expansion of the corner in that direction. If the buffer structure abuts against the corner and the battery casing along the thickness direction of the electrode assembly, the friction between the buffer structure and the inner wall of the battery casing can hinder the movement of the corner along the first direction, while also reducing the probability of direct friction between the corner and the inner wall of the battery casing. If the buffer structure abuts between two adjacent electrode assemblies, it can provide a buffer space between them, reducing the probability of stress concentration due to direct contact at the corner. This design effectively reduces the probability of cracking at the corners of the electrode assembly, thus improving the reliability of the battery device.

[0046] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system for such an electrical device can be constructed using battery cells and battery devices disclosed in this application.

[0047] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0048] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0049] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0050] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0051] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 20 and a battery cell 10, with the battery cell 10 housed within the housing 20. The housing 20 provides a accommodating space for the battery cell 10, and the housing 20 can adopt various structures. In some embodiments, the housing 20 may include a first portion 201 and a second portion 202, which overlap each other, and together define a accommodating space for accommodating the battery cell 10. The second portion 202 may be a hollow structure with an opening 121 at one end, and the first portion 201 may be a plate-like structure, covering the opening 121 side of the second portion 202, so that the first portion 201 and the second portion 202 together define the accommodating space; alternatively, the first portion 201 and the second portion 202 may both be hollow structures with an opening 121 on one side, with the opening 121 side of the first portion 201 covering the opening 121 side of the second portion 202. Of course, the box 20 formed by the first part 201 and the second part 202 can be of various shapes, such as cylinder, cuboid, etc.

[0052] In the battery device 100, there can be multiple battery cells 10, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel configurations. Multiple battery cells 10 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 10 is housed within the housing 20. Alternatively, the battery device 100 can also consist of multiple battery cells 10 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 20. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 10.

[0053] Each battery cell 10 can be a secondary battery device 100 or a primary battery device 100; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 10 can be cylindrical, flat, cuboid, or other shapes.

[0054] Please refer to Figure 3 , Figure 3This is an exploded structural diagram of a battery cell 10 provided in some embodiments of this application. The battery cell 10 refers to the smallest unit constituting the battery device 100. For example... Figure 3 The battery cell 10 includes a battery casing 1, an electrode assembly 2, and other functional components. In some examples, the battery casing 1 may also include an end cap 11 and a housing 12.

[0055] End cap 11 refers to a component that covers the opening 121 of housing 12 to isolate the internal environment of battery cell 10 from the external environment. The shape of end cap 11 can be adapted to the shape of housing 12 to fit it. Optionally, end cap 11 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 11 is not easily deformed under pressure and impact, allowing battery cell 10 to have higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on end cap 11. Electrode terminals can be used for electrical connection with electrode assembly 2 for outputting or inputting electrical energy to battery cell 10. In some embodiments, end cap 11 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of battery cell 10 reaches a threshold. The material of end cap 11 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 11. The insulating element can be used to isolate the electrical connection components within the housing 12 from the end cap 11 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0056] The housing 12 is a component used to cooperate with the end cap 11 to form the internal environment of the battery cell 10. This internal environment can accommodate the electrode assembly 2, electrolyte, and other components. The housing 12 and the end cap 11 can be independent components. An opening 121 can be provided on the housing 12, and the end cap 11 can close the opening 121 to form the internal environment of the battery cell 10. Alternatively, the end cap 11 and the housing 12 can be integrated. Specifically, the end cap 11 and the housing 12 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 12, the end cap 11 closes the housing 12. The housing 12 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 12 can be determined according to the specific shape and size of the electrode assembly 2. The material of the housing 12 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0057] Electrode assembly 2 is the component in the battery cell 10 where the electrochemical reaction occurs. The casing 12 may contain one or more electrode assemblies 2. Electrode assembly 2 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is typically provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of electrode assembly 2, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0058] According to some embodiments of this application, please refer to Figures 4 to 6 This application provides a battery cell 10, which includes a battery casing 1, an electrode assembly 2, and a buffer structure 3. The electrode assembly 2 is housed within the battery casing 1 and includes a straight portion 21 and two corner portions 22 respectively disposed at both ends of the straight portion 21 along a first direction X, the first direction X intersecting the thickness direction Z of the electrode assembly 2. The battery cell 10 further includes the buffer structure 3, which protrudes from the surface of at least one corner portion 22.

[0059] The battery casing 1 refers to a structure that provides a closed space for the electrode assembly 2. It can be a structure with end caps 11 or without end caps 11. For example, the battery casing 1 can be an integrated aluminum casing. When the electrode assembly 2 expands, it abuts against the inner wall of the battery casing 1. As the expansion continues, the expansion force causes the corner portion 22 of the electrode assembly 2 to move laterally; or the corner portions 22 of two adjacent electrode assemblies 2 may squeeze each other due to the expansion force, resulting in stress concentration on the corner portion 22, which in turn makes the corner portion 22 prone to cracking.

[0060] Therefore, in this embodiment, a buffer structure 3 is provided on the surface of at least one corner portion 22, so that when the electrode assembly 2 expands and pushes against the casing, the buffer structure 3 can directly abut against the inner wall of the battery casing 1 instead of the corner portion 22; or, it can abut between the corner portions 22 of two electrode assemblies 2. Please refer to... Figure 6 When the buffer structure 3 abuts against the inner wall of the battery casing 1 along the first direction X, it can directly restrict the expansion of the corner portion 22 along the first direction X. Please refer to... Figure 4 When the buffer structure 3 abuts against the inner wall of the battery casing 1 along the thickness direction Z of the electrode assembly 2, the friction between the buffer structure 3 and the inner wall of the battery casing 1 can hinder the movement of the corner portion 22 along the first direction X; at the same time, it can also effectively buffer the corner portion 22 along the thickness direction Z of the electrode assembly 2. Please refer to... Figure 5When the buffer structure 3 abuts between two adjacent electrode components 2, it can provide a buffer space between the two adjacent electrode components 2, reducing the probability of stress concentration caused by direct contact between the two at the corner 22.

[0061] It is understood that providing a buffer structure 3 on the surface of the corner 22 can effectively reduce the probability of cracking of the electrode assembly 2 at the corner 22, which is beneficial to improving the reliability of the battery device 100. The buffer structure 3 refers to a structure that can provide a certain buffering effect, and it can have a certain elastic compression function, such as, but not limited to, rubber, sponge pads, separators, etc. At the same time, the buffer structure 3 can be configured to abut against the inner wall of the battery casing 1 or between two adjacent electrode assemblies 2 when the electrode assembly 2 is in an expanded state.

[0062] The buffer structure 3 can be disposed on one side of the corner portion 22 along the first direction X, or on one side of the corner portion 22 along the thickness direction Z of the electrode assembly 2; of course, it can also be disposed on both sides of the corner portion 22 along the first direction X and along the thickness direction Z of the electrode assembly 2. Furthermore, the buffer structure 3 can be disposed on one corner portion 22, or on both corner portions 22.

[0063] A buffer structure 3 is provided on the surface of the corner 22. During the expansion process, the buffer structure 3 can abut against the inner wall of the battery case 1 or between two adjacent electrode components 2, forming a gap between the battery case 1 and the electrode components 2 or between two adjacent electrode components 2, providing a channel for the wetting or heat dissipation of the electrode components 2, and reducing the impact on the wetting or heat dissipation of the electrode components 2.

[0064] In addition, when the buffer structure 3 abuts against the inner wall of the battery case 1 during the expansion process, the buffer structure 3 can fix the electrode assembly 2, reduce the influence of external vibration on the electrode assembly 2, and improve the reliability of the battery device 100.

[0065] This design effectively reduces the probability of cracking of the electrode assembly 2 at the corner 22, which helps to improve the reliability of the battery device 100.

[0066] Optionally, according to some embodiments of this application, please refer to Figure 4 At least a portion of the buffer structure 3 is disposed on at least one side of the electrode assembly 2 along its own thickness direction Z, and it includes a first buffer member 31, which protrudes from the corner portion 22 on one side along the thickness direction Z of the electrode assembly 2.

[0067] When there is only one electrode assembly 2, the buffer structure 3 can be located on at least one side of the electrode assembly 2 along the thickness direction Z, so that when expansion occurs, the first buffer member 31 of the buffer structure 3 can abut against the inner wall of the battery case 1. When there are multiple electrode assemblies 2, at least some of the electrode assemblies 2 are stacked on top of each other, and the first buffer member 31 of the buffer structure 3 can abut against the inner wall of the battery case 1 or between two adjacent electrode assemblies 2.

[0068] When the first buffer 31 abuts against the inner wall of the battery case 1 along the thickness direction Z of the electrode assembly 2, it can not only replace the corner portion 22 directly abutting against the inner wall of the battery case 1, reducing the risk of stress concentration; but also, by utilizing the friction between the first buffer 31 and the battery case 1, it can restrict the corner portion 22 from moving outward along the first direction X, reducing the wear caused by the outward extension of the corner portion 22 due to the friction behind the top of the case, and reducing the risk of cracking at the corner portion 22.

[0069] When the first buffer 31 abuts between the corners 22 of two adjacent electrode assemblies 2, it can prevent direct compression between the two adjacent corners 22, thus reducing the risk of cracking. The first buffer 31 refers to a structure with elastic compression, which can be, but is not limited to, rubber, sponge, diaphragm, etc. In some examples, the first buffer 31 can be configured to abut against the inner wall of the battery casing 1 or between two adjacent electrode assemblies 2.

[0070] In addition, there are various ways in which the first buffer member 31 is distributed on the surface of the corner portion 22. For example, the first buffer member 31 can extend along the second direction Y to the opposite ends of the electrode assembly 2; or the first buffer member 31 can be distributed at intervals along the second direction Y, etc., wherein the first direction X, the second direction Y and the thickness direction Z of the electrode assembly 2 intersect each other, and the three are not coplanar.

[0071] With this design, a first buffer 31 is provided on at least one side of the corner portion 22 along the thickness direction Z of the electrode assembly 2. This can reduce the outward extension of the corner portion 22 due to friction from the top shell, or limit the force concentration caused by direct compression between two adjacent corner portions 22. This can effectively reduce the probability of the electrode assembly 2 cracking at the corner portion 22 and improve the reliability of the battery device 100.

[0072] Optionally, according to some embodiments of this application, please refer to Figure 7 A junction end 23 is formed at the junction between the straight portion 21 and the corner portion 22, and the first buffer member 31 extends along the first direction X to or beyond the junction end 23 adjacent to itself.

[0073] The junction 23 refers to the structure connecting the straight portion 21 and the corner portion 22, where stress is relatively easy to concentrate. When the first buffer 31 extends to or beyond the junction 23, the first buffer 31 can protect the connection between the straight portion 21 and the corner portion 22, reducing stress concentration at the connection between the straight portion 21 and the corner portion 22, and improving the structural strength of the electrode assembly 2 during the expansion process.

[0074] When the first buffer 31 extends beyond the junction end 23, a portion of the first buffer 31 is located on the surface of the corner portion 22, and another portion is located on the surface of the straight portion 21, which can reduce the probability of cracking at the junction end 23. Specifically, on one side of the electrode assembly 2 along its own thickness direction Z, the first buffer 31 can be provided on the surface of one of the corner portions 22, or it can be provided on the surfaces of both corner portions 22 simultaneously.

[0075] This design extends the first buffer 31 to or beyond the junction end 23, which can effectively buffer and protect the junction end 23, reduce the risk of stress concentration at the junction end 23, improve structural strength, and thus reduce the probability of the junction end 23 cracking due to expansion.

[0076] Optionally, according to some embodiments of this application, please refer to Figure 8 The buffer structure 3 located on the side of the electrode assembly 2 along its own thickness direction Z includes two first buffer members 31, which are respectively disposed at two corner portions 22.

[0077] On one side of the electrode assembly 2 along its thickness direction Z, two first buffer members 31 can be respectively disposed on the surfaces of the two corner portions 22. In this way, during the expansion process, the two first buffer members 31 can abut against the inner wall of the battery case 1. The friction between the two first buffer members 31 and the inner wall of the battery case 1 hinders the movement of the two corner portions 22 along the first direction X, reduces the consumption of the corner portions 22 extending outward, and improves the structural stability of the electrode assembly 2.

[0078] With this design, first buffers 31 are provided at the two corners 22 respectively, which can block the movement of the corners 22 along the first direction X during the expansion process, reduce the consumption of the corners 22 extending outward, reduce the probability of cracking at the corners 22 during the expansion process, and improve the reliability of the battery device 100.

[0079] Optionally, according to some embodiments of this application, please refer to Figure 8 The buffer structure 3 located on the side of the electrode assembly 2 along its own thickness direction Z also includes a first connector 32, which is connected between two first buffers 31.

[0080] The first connector 32 refers to the structure connecting the two first buffers 31, which can connect the two first buffers 31 into a single structure. In this way, when the two first buffers 31 abut against the inner wall of the battery case 1, the first connector 32 can also abut against the inner wall of the battery case 1, which can increase the friction between the buffer structure 3 and the battery case 1, reduce the outward movement of the corner 22 along the first direction X, and reduce the probability of the corner 22 cracking.

[0081] Meanwhile, the first connecting member 32 connected between the two first buffer members 31 can exert a certain traction effect between the two first buffer members 31, reduce the movement of the two first buffer members 31 in opposite directions, and reduce the consumption of the corner 22 extending outward, thus reducing the probability of cracking.

[0082] When the two first buffer members 31 abut between two adjacent electrode assemblies 2, the first connecting member 32 can also abut against the two adjacent electrode assemblies 2, providing buffer space for the two electrode assemblies 2, reducing the possibility of direct compression between the two electrode assemblies 2, thereby reducing stress concentration at the corner 22.

[0083] The connection between the first connector 32 and the first buffer 31 can be achieved by bonding, binding, or other methods; alternatively, the first connector 32 and the first buffer 31 can be an integrated structure. Furthermore, the first connector 32 can also be disposed on the surface of the straight portion 21 and extend along the first direction X to the two first buffers 31.

[0084] Furthermore, the number of first connectors 32 can be one or more. Please refer to... Figure 9 When there are multiple first connectors 32, each first connector 32 can be connected between two first buffers 31 at intervals.

[0085] This design introduces a first connector 32, which makes the two first buffers 31 form an integral structure. This can increase the friction between the buffer structure 3 and the battery case 1 and reduce the consumption of the corner 22 extending outward. Alternatively, it can reduce the possibility of the two electrode assemblies 2 being directly squeezed, thereby reducing the stress concentration at the corner 22 and improving the stability of the structure.

[0086] Optionally, according to some embodiments of this application, please refer to Figure 8 Each of the first buffer members 31 has a larger dimension along the second direction Y than the first connector 32 along the second direction Y. The first direction X, the second direction Y and the thickness direction Z of the electrode assembly 2 intersect each other and are not coplanar.

[0087] It can be seen that the size of the first connecting member 32 connected between the two first buffer members 31 is relatively small. If the number of the first connecting member 32 is one, it can form an or approximately I-shaped structure with the first buffer members 31 on both sides.

[0088] In some specific examples, the two ends of the first buffer 31 along the second direction Y respectively extend beyond the two ends of the first connector 32 along the second direction Y.

[0089] This design can relatively increase the buffer area on the corner 22 and improve the protective effect; at the same time, it can relatively reduce the space occupied on the straight part 21 and save the material used for the buffer structure 3 on the straight part 21.

[0090] Optionally, according to some embodiments of this application, please refer to Figure 4 The dimension of the first buffer 31 along the first direction X is denoted as W1, and the dimension of the battery case 1 along the first direction X is denoted as W0, wherein 5%≤W1 / W0≤50%.

[0091] The ratio between size W1 and size W0 can be between 5% and 50%, for example, but not limited to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0092] This design controls the ratio between size W1 and size W0 to between 5% and 50%. While ensuring that the first buffer 31 occupies a reasonable amount of space within the battery casing 1, it increases the protection range on the corner 22, improves the buffer protection of the corner 22, and reduces the probability of cracking at the corner 22.

[0093] Optionally, according to some embodiments of this application, please refer to Figure 10 and Figure 11 The electrode assembly 2 includes multiple electrode assemblies, and at least some of the electrode assemblies 2 are stacked sequentially along their respective thickness direction Z. In the thickness direction Z of the electrode assembly 2, at least one of the two adjacent electrode assemblies 2 and the electrode assembly 2 and the battery casing 1 is provided with a buffer structure 3.

[0094] When at least some of the electrode assemblies 2 are stacked sequentially along their respective thickness direction Z, the electrode assemblies 2 at both ends can abut against the inner wall of the battery casing 1 during expansion, while the electrode assemblies 2 in the middle can press against each other. Therefore, a buffer structure 3 is provided between the electrode assembly 2 and the battery casing 1 and / or between two adjacent electrode assemblies 2, which can replace the electrode assembly 2 directly abutting against the inner wall of the battery casing 1 or adjacent electrode assemblies 2, thus providing effective buffering.

[0095] For specific examples, please refer to Figure 11 In the thickness direction Z of the electrode assembly 2, a buffer structure 3 is provided between each two adjacent electrode assemblies 2 and between the electrode assembly 2 and the battery casing 1.

[0096] The buffer structure 3 in this embodiment may include a first buffer 31, or two first buffers 31 and a first connector 32 connected between the two first buffers 31.

[0097] This design incorporates a buffer structure 3 between the electrode assembly 2 and the battery casing 1, and / or between two adjacent electrode assemblies 2, which effectively buffers the stress concentration at the corner 22, reduces the probability of cracking at the corner 22, and improves the reliability of the battery device 100.

[0098] Optionally, according to some embodiments of this application, please refer to Figure 12 At least a portion of the buffer structure 3 is disposed on at least one side of the electrode assembly 2 along the first direction X, and it includes a second buffer member 33, which protrudes from the corner portion 22 on one side along the first direction X.

[0099] Since the buffer structure 3 is provided on at least one side of the electrode assembly 2 along the first direction X, during the expansion process, the second buffer 33 of the buffer structure 3 abuts against the inner wall of the battery case 1, which can directly limit the expansion of the corner 22 along the first direction X and reduce the probability of cracking at the corner 22.

[0100] Meanwhile, the second buffer 33 abuts against the inner wall of the battery case 1. In this way, the friction between the second buffer 33 and the inner wall of the battery case 1 can reduce the movement of the electrode assembly 2 along its own thickness direction Z, reduce the expansion of the electrode assembly 2 along the thickness direction Z, and improve the stability of the structure.

[0101] The second buffer 33 refers to a structure with elastic compression, which may be, but is not limited to, rubber, sponge, diaphragm, etc. In some examples, the second buffer 33 may be configured to abut against the inner wall of the battery casing 1.

[0102] The second buffer 33 can be distributed in various ways on the surface of the corner 22. For example, the second buffer 33 can extend along the second direction Y to the opposite ends of the electrode assembly 2; or the first buffer 31 can be distributed at intervals along the second direction Y, etc., wherein the first direction X, the second direction Y and the thickness direction Z of the electrode assembly 2 intersect each other, and the three are not coplanar.

[0103] In addition, in some examples, a portion of the buffer structure 3 may be disposed on at least one side of the electrode assembly 2 along its own thickness direction Z, and another portion of the buffer structure 3 may be disposed on at least one side of the electrode assembly 2 along the first direction X.

[0104] With this design, a second buffer 33 is provided on at least one side of the corner portion 22 along the first direction X, which can effectively buffer the expansion of the corner portion 22 along the first direction X; at the same time, the friction between the second buffer 33 and the inner wall of the battery case 1 reduces the expansion of the electrode assembly 2 along the thickness direction Z, which is beneficial to improving the structural stability of the electrode assembly 2.

[0105] Optionally, according to some embodiments of this application, please refer to Figure 12 The electrode assembly 2 includes multiple components, and at least some of the electrode assemblies 2 are stacked sequentially along their respective thickness direction Z. The buffer structure 3 located on one side of the electrode assembly 2 along the first direction X includes multiple second buffer members 33, and each second buffer member 33 protrudes from the corresponding corner portion 22 on one side along the first direction X.

[0106] On one side of the electrode assembly 2 along the first direction X, each second buffer 33 is respectively disposed on the corresponding corner portion 22, so that the corner portion 22 of each electrode assembly 2 can be effectively buffered by the corresponding second buffer 33 during the expansion process, reducing the expansion extension of the corner portion 22 along the first direction X, and reducing the risk of cracking of the corner portion 22.

[0107] In some specific examples, the electrode assembly 2 is provided with buffer structures 3 on both sides of the first direction X, and each buffer structure 3 includes multiple second buffers 33, and each second buffer 33 is provided on the corresponding corner 22.

[0108] With this design, a second buffer 33 is provided on each corner 22. The expansion of the corner 22 along the first direction X can be reduced by the second buffer 33, which can effectively buffer the stress concentration on the corner 22, reduce the probability of cracking at the corner 22, and improve the reliability of the battery device 100.

[0109] Optionally, according to some embodiments of this application, please refer to Figure 12 The buffer structure 3 located on one side of the electrode assembly 2 along the first direction X also includes a second connector 34. On one side of the electrode assembly 2 along the first direction X, at least two adjacent second buffers 33 are connected by a second connector 34.

[0110] The second connector 34 is a structure that connects the two second buffers 33, allowing them to be connected as a single unit. When the two second buffers 33 abut against the inner wall of the battery casing 1, the second connector 34 also abuts against the inner wall of the battery casing 1, limiting the expansion of the corner portion 22 along the first direction X. Simultaneously, it increases the friction between the buffer structure 3 and the battery casing 1, reducing the movement of the corner portion 22 along the thickness direction Z, and lowering the probability of cracking of the corner portion 22.

[0111] Meanwhile, the second connector 34 connected between the two second buffers 33 can exert a certain traction between the two second buffers 33, reduce the movement of the two second buffers 33 in opposite directions, reduce the wear of the corner 22 extending outward, and reduce the probability of cracking.

[0112] The connection between the second connector 34 and the second buffer 33 can be by bonding, binding, etc.; or, the second connector 34 and the second buffer 33 can be an integrated structure.

[0113] Furthermore, the number of second connectors 34 can be one or more. Please refer to [reference needed]. Figure 13 When there are multiple second connectors 34, each second connector 34 can be connected between two second buffers 33 at intervals.

[0114] This design introduces a second connector 34, which makes the two second buffers 33 form an integral structure. This can limit the expansion of the corner 22 along the first direction X. At the same time, it can also increase the friction between the buffer structure 3 and the battery shell 1, reduce the movement of the corner 22 along the thickness direction Z, reduce the probability of the corner 22 cracking, and improve the stability of the structure.

[0115] Optionally, according to some embodiments of this application, please refer to Figure 12 The dimensions of two adjacent second buffer members 33 along the second direction Y are both larger than the dimensions of the second connecting member 34 along the second direction Y. The first direction X, the second direction Y and the thickness direction Z of the electrode assembly 2 intersect each other, and the three are not coplanar.

[0116] It can be seen that the size of the second connecting member 34 connected between the two second buffer members 33 is relatively small. If the number of the second connecting member 34 is one, it can form an or approximately I-shaped structure with the second buffer members 33 on both sides.

[0117] In some specific examples, the two ends of the second buffer 33 along the second direction Y respectively extend beyond the two ends of the second connector 34 along the second direction Y.

[0118] This design can relatively increase the buffer area on the corner 22 and improve the protection effect; at the same time, it can relatively reduce the space occupied on the side of the electrode assembly 2 and save the material used for the buffer structure 3 on the side of the electrode assembly 2.

[0119] Optionally, according to some embodiments of this application, please refer to Figure 6 The dimension of the second buffer 33 along the thickness direction Z of the electrode assembly 2 is denoted as L1, and the dimension of the battery case 1 along the thickness direction Z of the electrode assembly 2 is denoted as L0, wherein 5%≤L1 / L0≤50%.

[0120] The ratio between dimension L1 and dimension L0 can be between 5% and 50%, for example, but not limited to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc.

[0121] This design controls the ratio between size L1 and size L0 to between 5% and 50%, thereby improving the buffer protection of the corner 22 and reducing the probability of cracking at the corner 22 while ensuring that the first buffer 31 occupies a reasonable amount of space within the battery casing 1.

[0122] Optionally, according to some embodiments of this application, please refer to Figure 7 The thickness of the buffer structure 3 is denoted as H1, and the thickness of the electrode assembly 2 is denoted as H0, wherein 1%≤H1 / H0≤15%.

[0123] The ratio between dimension H1 and dimension H0 can be between 1% and 15%, for example, but not limited to 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 15%, etc.

[0124] This design controls the ratio between size H1 and size H0 to between 1% and 15%, thereby improving the buffer protection of the corner 22 and reducing the probability of cracking at the corner 22 while ensuring that the first buffer 31 occupies a reasonable amount of space within the battery casing 1.

[0125] According to some embodiments of this application, optionally, the buffer structure 3 is configured as a structure with elastic compression, and the compression ratio of the buffer structure 3 is greater than or equal to 75%.

[0126] When the electrode assembly 2 expands, the buffer structure 3 can undergo elastic deformation to absorb part of the expansion at the corner 22. The compression ratio of the buffer structure 3 can be, but is not limited to, 75%, 80%, 85%, 90%, 95%, etc.

[0127] In some specific examples, the material of the buffer structure 3 can be rubber, sponge, diaphragm, etc.

[0128] This design, with the compression ratio of the buffer structure 3 being greater than or equal to 75%, improves the buffering effect of the buffer structure 3, effectively reducing the probability of cracking at the corner 22 and improving the reliability of the battery device 100.

[0129] According to some embodiments of this application, the buffer structure 3 is optionally configured to have an elastically compressible and porous structure.

[0130] The buffer structure 3 is designed as a porous structure, which allows it to have a certain porosity, reducing the impact on the wetting and heat dissipation of the electrode assembly 2. In some specific examples, the buffer structure 3 is a diaphragm.

[0131] This design effectively buffers and protects the battery assembly 2 while reducing the impact of wetting or heat dissipation, thus further improving the reliability of the battery device 100.

[0132] According to some embodiments of this application, this application provides a battery device 100, which includes a battery cell 10 as described above.

[0133] According to some embodiments of this application, this application provides an electrical device that includes the battery device 100 described above.

[0134] According to some embodiments of this application, please refer to Figures 4 to 13 This application provides a battery cell 10, which includes a battery casing 1, an electrode assembly 2, and a buffer structure 3. The electrode assembly 2 includes a straight portion 21 and two corner portions 22 respectively disposed at both ends of the straight portion 21. When the electrode assembly 2 has a buffer structure 3 on at least one side along its thickness direction Z, the buffer structure 3 includes two first buffer members 31 and a first connecting member 32 connected between the two first buffer members 31. When the electrode assembly 2 has a buffer structure 3 on at least one side along the first direction X, the buffer structure 3 includes two second buffer members 33 and a second connecting member 34 connected between the two second buffer members 33.

[0135] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, The battery cell includes: Battery casing (1); The electrode assembly (2) is housed in the battery case (1) and includes a flat portion (21) and two corner portions (22) respectively provided at both ends of the flat portion (21) along a first direction (X), the first direction (X) intersecting the thickness direction (Z) of the electrode assembly (2); A buffer structure (3) protrudes from the surface of at least one of the corner portions (22); At least a portion of the buffer structure (3) is disposed on at least one side of the electrode assembly (2) along the first direction (X), and it includes a second buffer member (33) which protrudes from the corner portion (22) on one side along the first direction (X).

2. The battery cell according to claim 1, characterized in that, At least a portion of the buffer structure (3) is disposed on at least one side of the electrode assembly (2) along its own thickness direction (Z), and it includes a first buffer member (31) which protrudes from the corner portion (22) on one side of the electrode assembly (2) along its thickness direction (Z).

3. The battery cell according to claim 2, characterized in that, A junction end (23) is formed at the junction between the straight portion (21) and the corner portion (22), and the first buffer (31) extends along the first direction (X) to or beyond the junction end (23) adjacent to itself.

4. The battery cell according to claim 2, characterized in that, The buffer structure (3) located on one side of the electrode assembly (2) along its own thickness direction (Z) includes two first buffer members (31), and the two first buffer members (31) are respectively disposed on the two corner portions (22).

5. The battery cell according to claim 4, characterized in that, The buffer structure (3) located on one side of the electrode assembly (2) along its own thickness direction (Z) further includes a first connector (32), which is connected between the two first buffers (31).

6. The battery cell according to claim 5, characterized in that, The dimensions of each of the first buffer members (31) along the second direction (Y) are larger than the dimensions of the first connector (32) along the second direction (Y), wherein the first direction (X), the second direction (Y) and the thickness direction (Z) of the electrode assembly (2) intersect each other and are not coplanar.

7. The battery cell according to claim 2, characterized in that, The dimension of the first buffer (31) along the first direction (X) is denoted as W1, and the dimension of the battery case (1) along the first direction (X) is denoted as W0, wherein 5%≤W1 / W0≤50%.

8. The battery cell according to any one of claims 1-7, characterized in that, The electrode assembly (2) includes a plurality of electrodes, at least some of which are stacked sequentially along their respective thickness directions (Z). In the thickness direction (Z) of the electrode assembly (2), at least one of the two adjacent electrode assemblies (2) and the electrode assembly (2) and the battery casing (1) is provided with the buffer structure (3).

9. The battery cell according to any one of claims 1-7, characterized in that, The electrode assembly (2) includes a plurality of electrodes, at least some of which are stacked sequentially along their respective thickness directions (Z). The buffer structure (3) located on one side of the electrode assembly (2) along the first direction (X) includes a plurality of second buffer members (33), and each second buffer member (33) protrudes from the corresponding corner portion (22) on one side along the first direction (X).

10. The battery cell according to claim 9, characterized in that, The buffer structure (3) located on one side of the electrode assembly (2) along the first direction (X) further includes a second connector (34), and at least two adjacent second buffers (33) are connected by the second connector (34) on one side of the electrode assembly (2) along the first direction (X).

11. The battery cell according to claim 10, characterized in that, The dimensions of two adjacent second buffer members (33) along the second direction (Y) are both larger than the dimensions of the second connector (34) along the second direction (Y), wherein the first direction (X), the second direction (Y) and the thickness direction (Z) of the electrode assembly (2) intersect each other and are not coplanar.

12. The battery cell according to claim 9, characterized in that, The dimension of the second buffer (33) along the thickness direction (Z) of the electrode assembly (2) is denoted as L1, and the dimension of the battery case (1) along the thickness direction (Z) of the electrode assembly (2) is denoted as L0, wherein 5%≤L1 / L0≤50%.

13. The battery cell according to any one of claims 1-7, characterized in that, The thickness of the buffer structure (3) is denoted as H1, and the thickness of the electrode assembly (2) is denoted as H0, wherein 1%≤H1 / H0≤15%.

14. The battery cell according to any one of claims 1-7, characterized in that, The buffer structure (3) is constructed to have elastic compression, and the compression ratio of the buffer structure (3) is greater than or equal to 75%; and / or, The buffer structure (3) is constructed to be elastically compressible and porous.

15. A battery device, characterized in that, The battery device comprises the battery cell according to any one of claims 1-14.

16. An electrical appliance, characterized in that, The electrical equipment includes the battery device as described in claim 15.

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