Battery monomer, battery device and electric device

Abstract

The utility model relates to a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly and a limiting component, the shell has an accommodating cavity. The electrode assembly is arranged in the accommodating cavity, the electrode assembly comprises a first pole piece, the first pole piece comprises a pole piece main body and a pole lug which are arranged along a first direction, at least part of the pole piece main body is provided with a first active material layer, and at least part of the pole lug is not provided with the first active material layer. The limiting component is arranged in the thickness direction of the battery monomer, at least part of the limiting component is arranged between the end part of the first active material layer along the first direction and the shell, and the thickness direction of the battery monomer is perpendicular to the first direction. According to the battery monomer provided by the invention, the limiting component can improve the defects of large gap difference and non-uniform distribution of each position along the first direction, so that the occurrence of an ion precipitation phenomenon is reduced, and the reliability of the battery monomer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery production, in particular to a battery monomer, a battery device and a power consumption device. BACKGROUND

[0002] Battery monomers are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc. The battery monomer can include cadmium-nickel batteries, hydrogen-nickel batteries, lithium-ion batteries and secondary alkaline zinc-manganese batteries, etc.

[0003] In the development of batteries, how to provide the reliability of the battery monomer is a technical problem to be solved in battery technology. UTILITY MODEL CONTENT

[0004] The present application provides a battery monomer, a battery device and a power consumption device, which aims to improve the reliability of the battery monomer to some extent.

[0005] In a first aspect, the present application provides a battery monomer, which comprises a shell, an electrode assembly and a limiting component. The shell has a receiving cavity. The electrode assembly is arranged in the receiving cavity, and the electrode assembly comprises a first pole piece, the first pole piece comprising a pole piece main body arranged in a first direction and a tab, at least part of the pole piece main body being provided with a first active material layer, and at least part of the tab being not provided with the first active material layer. The limiting component is arranged between the end of the first active material layer in the first direction and the shell in the thickness direction of the battery monomer, and the thickness direction of the battery monomer is perpendicular to the first direction.

[0006] The battery monomer provided by the present application has at least part of the limiting component arranged between the end of the first active material layer and the shell in the thickness direction of the battery monomer. The limiting component can improve the defects of large gap difference and uneven distribution between positions in the first direction, and the limiting component is also used for the shaping of the electrode assembly, limiting the expansion of the electrode assembly at the end, thereby reducing the occurrence of ion precipitation, to provide the reliability of the battery monomer.

[0007] According to an embodiment of the present application, the limiting component is a flexible limiting piece.

[0008] In these alternative embodiments, the flexible limiting piece can reduce the rigid damage to the electrode assembly that expands, reduce the mechanical damage of the electrode assembly, and cause the deformation of the pole piece and the occurrence of ion precipitation.

[0009] According to an embodiment of the present application, the battery monomer further comprises an electrolyte, and the electrolyte is contained in the receiving cavity. The limiting component is configured to absorb the expansion of the electrolyte.

[0010] In these optional embodiments, the limiting component is configured to absorb the electrolyte expansion, which not only reduces the mechanical damage to the electrode assembly, but also absorbs and releases the electrode assembly, wets the electrode assembly, and improves the cycle performance of the battery cell.

[0011] According to an embodiment of the present application, the limiting component is configured to increase in volume by 130% to 200% after absorbing the electrolyte.

[0012] In these optional embodiments, the arrangement can absorb an appropriate amount of electrolyte, and the volume expansion can effectively fill the gaps inside the battery and improve the defects of uneven gaps.

[0013] According to an embodiment of the present application, the limiting component is attached to at least one of the housing and the electrode assembly.

[0014] In these optional embodiments, the limiting component is attached to at least one of the housing and the electrode assembly to improve the connection stability of the limiting component.

[0015] According to an embodiment of the present application, the first active material layer includes a first base body and a first thinned portion arranged along the first direction, and the thickness of the first thinned portion is less than or equal to the thickness of the first base body. In the thickness direction of the battery cell, at least part of the limiting component is located between the first thinned portion and the housing.

[0016] In these optional embodiments, in the thickness direction of the battery cell, at least part of the limiting component is located between the first thinned portion and the housing, that is, at least part of the limiting component is arranged opposite to the first thinned portion, which not only reduces the difference in the gap between the middle region and the end region along the first direction, but also enables the limiting component to press the gap between the first active material layer and the separator at the end portion, thereby shortening the transmission path of the active ions, improving the ion precipitation phenomenon, and improving the reliability of the battery cell.

[0017] According to an embodiment of the present application, the projection of the limiting component along the thickness direction covers the projection of the first thinned portion along the thickness direction.

[0018] In these optional embodiments, the greater reduction in the uneven gaps of the battery cell leads to the defects of ion precipitation.

[0019] According to an embodiment of the present application, the battery cell includes at least two limiting components arranged at intervals along the first direction, wherein, in the thickness direction, at least one limiting component is arranged opposite to the first thinned portion, and at least one limiting component is arranged opposite to the end portion of the first base body along the first direction and away from the first thinned portion.

[0020] In these alternative embodiments, a plurality of limiting components are arranged along the first direction, such that the limiting components match the two ends of the first base along the first direction, and limit uneven expansion of the middle region and the two end regions of the electrode assembly.

[0021] According to an embodiment of the present application, the electrode assembly further comprises a second tab and a separator, the separator is used to separate the first tab and the second tab, the first tab and the second tab have opposite polarities, the first tab, the separator and the second tab are wound to form a bending region and a flat region connected to the bending region. At least part of the limiting component is arranged opposite to the flat region in the thickness direction.

[0022] In these alternative embodiments, the limiting component is arranged opposite to the flat region at least in part, which is conducive to the limiting component to extrude the end of the tab body along the first direction in a large area, thereby reducing the uneven gap phenomenon and more effectively improving the ion precipitation phenomenon.

[0023] According to an embodiment of the present application, the limiting component is further arranged opposite to the bending region in the thickness direction.

[0024] In these alternative embodiments, the limiting component is arranged opposite to the flat region and the bending region, and the limiting component has a large span as a whole, which can effectively reduce the defect of uneven gap on the one hand, and reduce the occurrence of stress concentration on the other hand.

[0025] According to an embodiment of the present application, the second tab comprises a second active material, and the second active material layer comprises a second base and a second thinned portion arranged along the first direction, the thickness of the second thinned portion is less than or equal to the thickness of the second base.

[0026] According to an embodiment of the present application, the second thinned portion is arranged opposite to the first thinned portion at least in part in the thickness direction, and the limiting component is arranged opposite to the second thinned portion at least in part.

[0027] In these alternative embodiments, the second thinned portion is arranged opposite to the first thinned portion at least in part, and at least part of the limiting component is arranged opposite to the first thinned portion and the second thinned portion, so that one limiting component can reduce the gap between the first thinned portion and the separator, the gap between the second thinned portion and the separator, and the defect of uneven gap as a whole, which can not only improve the ion precipitation phenomenon, but also further improve the overall layout compactness inside the battery monomer.

[0028] According to an embodiment of the present application, the projection of the limiting component covers the projection of the first thinned portion and the projection of the second thinned portion in the thickness direction.

[0029] According to an embodiment of the present application, the second thinning portion is located at one end of the second base body away from the first thinning portion in the first direction. The battery cell comprises at least two limiting components arranged at intervals along the first direction, wherein at least one limiting component is arranged opposite to the first thinning portion in the thickness direction, and at least one limiting component is arranged opposite to the second thinning portion in the thickness direction.

[0030] In these alternative embodiments, at least one limiting component is arranged opposite to the first thinning portion, and at least one limiting component is arranged opposite to the second thinning portion, so that the limiting components can reduce the defects of uneven gaps, and also have a lower number of components and a lower quality.

[0031] According to an embodiment of the present application, in the first direction, the size M of the limiting component and the size L of the pole piece body along the first direction satisfy: 0.03L≤M≤0.3L.

[0032] In these alternative embodiments, the limiting component has a suitable size in the first direction, thereby effectively inhibiting the expansion deformation of the electrode assembly and also reducing the impact on the skirt allowance of the electrode assembly.

[0033] According to an embodiment of the present application, the limiting component at least surrounds one turn of the electrode assembly.

[0034] In these alternative embodiments, the limiting component arranged around one turn of the electrode assembly makes the distance between the shell and the end of the electrode assembly uniform, appropriately limits the electrode assembly, reduces the movement of the electrode assembly, and helps to improve the reliability of the battery cell.

[0035] According to an embodiment of the present application, in the thickness direction of the battery cell, limiting components are arranged on opposite sides of the electrode assembly.

[0036] In these alternative embodiments, the limiting components arranged on opposite sides of the electrode assembly neither occupy too much space nor inhibit the expansion of the electrode assembly on both sides of the electrode assembly, so as to improve the phenomenon of uneven gaps.

[0037] According to an embodiment of the present application, the material of the limiting component is oriented polystyrene.

[0038] In these alternative embodiments, the oriented polystyrene expansion adhesive can be tightly bonded with the shell, the electrode assembly, etc., which helps to improve the overall structural stability of the battery and reduce the relative displacement and looseness between components. The oriented polystyrene expansion adhesive has good chemical corrosion resistance and strong electrolyte resistance, and can maintain stable performance inside the battery.

[0039] In a second aspect, the present application provides a battery device comprising the battery cell according to the foregoing.

[0040] Thirdly, this application provides an electrical device, including a battery cell or a battery device as described above, wherein the battery cell or battery device is used to store or provide electrical energy.

[0041] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0042] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0043] Figure 1 This is a schematic diagram of the structure of a vehicle provided in one embodiment of this application;

[0044] Figure 2 This is an exploded view of a battery device provided in an embodiment of this application;

[0045] Figure 3 This is an exploded view of a single battery cell provided in an embodiment of this application;

[0046] Figure 4 This is a cross-sectional view of a battery cell provided in an embodiment of this application;

[0047] Figure 5 for Figure 4 The diagram shown is an enlarged structural schematic of a single battery cell at point a according to an embodiment of this application.

[0048] Figure 6 This is a cross-sectional view of a battery cell provided in an embodiment of this application;

[0049] Figure 7 This is a partial structural schematic diagram of the electrode assembly of a battery cell provided in an embodiment of this application.

[0050] The accompanying drawings may not be drawn to scale.

[0051] Explanation of reference numerals in the attached figures:

[0052] 1000, vehicles;

[0053] 100. Battery assembly; 200. Controller; 300. Motor;

[0054] 10. Battery cell; 20. First housing; 30. Second housing;

[0055] 1. Outer shell; 11. Receiving cavity;

[0056] 2, electrode assembly; 21, first tab; 211, tab main body; 212, tab lug; 213, first active material layer; 2131, first base; 2132, first thinning portion; 22, second tab; 221, second active material layer; 2211, second base; 2212, second thinning portion; 23, spacer; 24, bending region; 25, flat region;

[0057] 3, limiting member;

[0058] z, thickness direction; x, first direction. DETAILED DESCRIPTION

[0059] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0060] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing specific embodiments of the present application and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0061] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0062] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect", "attach" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] The term "and / or" in the present application is only used to describe the relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0064] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length, width and other dimensions of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0065] "Multiple" appearing in the present application means two or more (including two).

[0066] When the battery cell is charged and discharged, the gap generated by the shrinking and swelling of the electrode assembly, and the large difference between the gap in the middle region and the gap in the end region, the uneven gap is easy to appear ion precipitation, such as ion precipitation phenomenon, ion precipitation not only makes the performance of the battery cell decline, the cycle life is greatly shortened, but also limits the fast charging capacity of the battery cell. When ion precipitation is serious, such as lithium precipitation, the lithium ions detached can form a lithium layer on the surface of the negative electrode plate, which may cause the risk of short circuit between the adjacent positive electrode plate and negative electrode plate, reducing the reliability of the battery cell. The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute the prior art.

[0067] The battery cell provided by the present application is provided. In the thickness direction of the battery cell, at least part of the limiting component is arranged between the end of the first active material layer and the shell. The limiting component can improve the defect that the gap difference between each position in the first direction is large and unevenly distributed; and the limiting component is also used for the shaping of the electrode assembly, limiting the expansion of the electrode assembly at the end, thereby reducing the occurrence of ion precipitation phenomenon, to provide the reliability of the battery cell.

[0068] The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute the prior art.

[0069] The battery device of the present application will be described in detail below.

[0070] The battery device mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, parallel or mixed connection through the busbar component.

[0071] In some embodiments, the battery cell assembly is typically formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells into one independent module. As an example, the battery module can be formed by bundling a plurality of battery cells by a cable tie.

[0072] In some embodiments, the battery device can be a battery pack, which includes a box and one or more battery cell assemblies, the battery cell assemblies are accommodated in the box.

[0073] As an example, the battery cell assembly can be a battery module, which can be accommodated in the box by fixing the battery module in the box.

[0074] As an example, the battery cell assembly can also be accommodated in the box by fixing a plurality of battery cells directly in the box.

[0075] In the embodiments of the present application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be activated by charging after discharging the battery cell.

[0076] The battery cell can include, but is not limited to, a solid-state battery cell, a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0077] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, or a battery cell of other shapes, the prismatic battery cell includes a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, etc., which is not particularly limited in the present application.

[0078] In some embodiments, the box can be part of the chassis structure of the vehicle. For example, part of the box can become at least part of the floor of the vehicle, or part of the box can become at least part of the cross beam and longitudinal beam of the vehicle.

[0079] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0080] The battery device disclosed by the embodiments of the present application can be used in a power consumption device using the battery device as a power source or a variety of energy storage systems using the battery device as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric aircraft toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0081] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0082] Referring to Figure 1 An embodiment of the present application provides a vehicle 1000. The vehicle 1000 can be a fuel automobile, a gas automobile, or a new energy automobile. The new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. In an embodiment of the present application, the vehicle 1000 can include a motor 300, a controller 200, and a battery 100. The controller 200 is used to control the battery 100 to supply power to the motor 300. The motor 300 is connected to the wheels through a transmission mechanism, thereby driving the vehicle 1000 to travel. The battery 100 can be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000. In one example, the battery 100 can be arranged at the bottom, the front, or the rear of the vehicle 1000. The battery 100 can be used to supply power to the vehicle 1000. In one example, the battery 100 can be used as an operating power source of the vehicle 1000, for the circuit system of the vehicle 1000. For example, the battery 100 can be used for the power demand of starting, navigation, and running of the vehicle 1000.

[0083] Please refer to Figure 2 , Figure 2 An exploded view of the battery device 100 provided by some embodiments of the present application is shown. The battery 100 includes a box body and a battery cell 10. In some embodiments, the box body can include a first box body 20 and a second box body 30, the first box body 20 and the second box body 30 are covered with each other, and the first box body 20 and the second box body 30 jointly define a containing space for containing the battery cell 10. The second box body 30 can be a hollow structure with one end open, and the first box body 20 can be a plate-shaped structure, which is covered on the open side of the second box body 30 to jointly define the containing space with the second box body 30; the first box body 20 and the second box body 30 can also be hollow structures with one side open, and the open side of the first box body 20 is covered on the open side of the second box body 30. Of course, the box body formed by the first box body 20 and the second box body 30 can be in various shapes, such as a cylinder, a cuboid, etc.

[0084] In the battery 100, the battery cell 10 can be multiple, and the multiple battery cells 10 can be connected in series or in parallel or in a mixed manner. The mixed manner means that the multiple battery cells 10 are connected in series and in parallel. The multiple battery cells 10 can be directly connected in series or in parallel or in a mixed manner, and the whole of the multiple battery cells 10 is accommodated in the box. Of course, the battery 100 can also be that the multiple battery cells 10 are connected in series or in parallel or in a mixed manner to form a battery module, and the multiple battery modules are connected in series or in parallel or in a mixed manner to form a whole, and are accommodated in the box. The battery 100 can also include other structures, for example, the battery 100 can also include a current collecting component for realizing the electrical connection between the multiple battery cells 10.

[0085] Each battery cell 10 can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the present application are not limited thereto.

[0086] The battery cell 10 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc.

[0087] Referring to Figure 3 , Figure 3 is an exploded view of the battery cell provided by an embodiment of the present application. The battery cell 10 includes a shell 1, and the shell 1 includes an end cover and a housing. The end cover refers to a component that covers the opening of the housing to isolate the internal environment of the battery cell 10 from the external environment. Without limitation, the shape of the end cover can be adapted to the shape of the housing to fit the housing. Alternatively, the end cover can be made of a material with certain hardness and strength (such as aluminum alloy), so that the end cover is not easy to deform when subjected to extrusion and collision, so that the battery cell 10 can have higher structural strength, and the safety performance can also be improved. Functional components such as electrode terminals can be provided on the end cover. The electrode terminals can be used to electrically connect with the electrode assembly 2 for outputting or inputting the electrical energy of the battery cell 10.

[0088] In some embodiments, a pressure relief mechanism (not labeled in the figure) for relieving the internal pressure of the battery cell 10 when the internal pressure or temperature of the battery cell 10 reaches a threshold value can also be provided on the end cover. The material of the end cover can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. The embodiments of the present application do not make special limitations thereto.

[0089] In some embodiments, an insulating member can also be provided on the inner side of the end cover. The insulating member can be used to isolate the electrical connection components in the housing from the end cover to reduce the risk of short circuit.

[0090] The shell is a component for fitting the end cover to form an internal environment of the battery cell 10, wherein the formed internal environment can be used to accommodate the electrode assembly 2, electrolyte and other components. The shell and the end cover can be independent components, and an opening can be provided on the shell, and the end cover is made to cover the opening to form the internal environment of the battery cell 10. Without limitation, the end cover and the shell can also be integrated, specifically, the end cover and the shell can form a common connecting surface before other components enter the shell, and when it is necessary to seal the internal environment of the shell, the end cover is made to cover the shell.

[0091] The shell can be various shapes and various sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly 2. The material of the shell can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special limitations.

[0092] Referring to Figure 4 to Figure 6 , Figure 4 is a cross-sectional view of a battery cell provided by an embodiment of the present application; Figure 5 is Figure 4 is an enlarged structural schematic view of the battery cell provided by an embodiment of the present application at a; Figure 6 is a cross-sectional view of a battery cell provided by an embodiment of the present application.

[0093] As shown in Figure 3 to Figure 6 , the present application provides a battery cell 10, which comprises a shell 1, an electrode assembly 2 and a limiting component 3. The shell 1 has an accommodation cavity 11. The electrode assembly 2 is arranged in the accommodation cavity 11, and the electrode assembly 2 comprises a first electrode sheet 21, the first electrode sheet 21 comprises an electrode sheet main body 211 arranged along a first direction x and a tab 212, at least part of the electrode sheet main body 211 is provided with a first active material layer 213, and at least part of the tab 212 is not provided with the first active material layer 213. The limiting component 3 is arranged between the end of the first active material layer 213 along the first direction x and the shell 1 in a thickness direction z of the battery cell 10, and the thickness direction z of the battery cell 10 is perpendicular to the first direction x.

[0094] The limiting component 3 of Figure 3 is arranged in the interior of the shell 1, so the limiting component 3 is represented by a dashed line.

[0095] The electrode assembly 2 is a component in which electrochemical reactions occur in the battery cell 10. One or more electrode assemblies 2 can be contained in the shell 1. The electrode assembly 2 is optionally formed by winding a positive electrode sheet and a negative electrode sheet, and an isolation film is usually arranged between the positive electrode sheet and the negative electrode sheet. It can also be a stacked structure formed by stacking a positive electrode sheet, an isolation member 23 and a negative electrode sheet.

[0096] The electrode assembly 2 is formed in a jelly-roll structure by winding a positive electrode sheet, a separator 23, and a negative electrode sheet, and the electrode assembly 2 is rectangular, and the axial direction of the electrode assembly 2 is the same as the height direction. Of course, in other examples, the cross section of the electrode assembly 2 perpendicular to the height direction can also be elliptical or cylindrical, etc.

[0097] In the embodiment of the present application, the first electrode sheet 21 includes an electrode sheet body 211 and a tab 212 extending from one end of the electrode sheet body 211 in the first direction x, the electrode sheet body 211 is the region where the electrode assembly 2 chemically reacts in the battery cell 10, the tab 212 is connected to one end of the electrode sheet body 211, and the tab 212 is used to output or input the electrical energy of the electrode assembly 2. The first electrode sheet 21 is a positive electrode sheet, or the first electrode sheet 21 is a negative electrode sheet.

[0098] In the embodiment of the present application, the first electrode sheet 21 includes an electrode sheet body 211 and a tab 212 extending from one end of the electrode sheet body 211 in the first direction x, the electrode sheet body 211 is the region where the electrode assembly 2 chemically reacts in the battery cell 10, the tab 212 is connected to one end of the electrode sheet body 211, and the tab 212 is used to output or input the electrical energy of the electrode assembly 2. The first electrode sheet 21 is a positive electrode sheet, or the first electrode sheet 21 is a negative electrode sheet.

[0099] In the embodiment of the present application, when the battery cell 10 is in a rectangular structure, the thickness direction z of the battery cell 10 is the layout direction of the two large faces of the battery cell 10. When the battery cell 10 is in a cylindrical structure, the thickness direction z of the battery cell 10 is the radial direction of the battery cell 10.

[0100] At least part of the limiting member 3 is arranged between the end of the first active material layer 213 in the first direction x and the case 1, and the limiting member is used for the shaping of the electrode assembly 2, limiting the expansion of the electrode assembly 2 at the end, and reducing the defect of uneven overall gap.

[0101] In the embodiment of the present application, the first active material layer 213 has opposite first and second ends in the first direction x. In the thickness direction of the battery cell 10, the limiting member 3 is arranged between the first end and the case 1.

[0102] In the embodiment of the present application, the first active material layer 213 has opposite first and second ends in the first direction x. In the thickness direction of the battery cell 10, the limiting member 3 is arranged between the second end and the case 1.

[0103] In the embodiment of the present application, the first active material layer 213 has opposite first and second ends in the first direction x. In the thickness direction of the battery cell 10, the battery cell 10 includes a plurality of limiting members 3, part of the limiting members 3 are arranged between the first end and the case 1, and the other part of the limiting members 3 are arranged between the second end and the case 1.

[0104] The battery cell 10 provided in the present application is configured such that at least part of the limiting component 3 is arranged between the end of the first active material layer 213 and the shell 1 in the thickness direction z of the battery cell 10. The limiting component 3 can improve the defect of large gap difference between positions in the first direction x and uneven distribution, and the limiting component 3 is also used for the shaping of the electrode assembly 2, limits the expansion of the electrode assembly 2 at the end, thereby reducing the occurrence of ion precipitation, to provide the reliability of the battery cell 10.

[0105] According to an embodiment of the present application, the limiting component 3 is a flexible limiting member.

[0106] The flexible limiting member realizes the limiting function of the internal components of the battery through the elastic deformation of itself. When the battery is subjected to internal pressure changes, the flexible limiting member can absorb and disperse these forces, wherein the flexible limiting member can deform itself, and the flexible limiting member can also deform by absorbing some substances, such as electrolyte, etc. Compared with the rigid limiting member, the flexible limiting member has a certain elastic deformation capability.

[0107] Specifically, the flexible limiting member includes rubber, foam, silica gel, expansion glue, etc.

[0108] In these alternative embodiments, the flexible limiting member can reduce the rigid damage to the electrode assembly 2 that expands, reduce the mechanical damage of the electrode assembly 2, and cause the deformation of the pole piece and the occurrence of ion precipitation.

[0109] According to an embodiment of the present application, the battery cell 10 further includes electrolyte, and the electrolyte is contained in the containing cavity 11. The limiting component 3 is configured to absorb the expansion of the electrolyte.

[0110] The limiting component 3 can absorb the electrolyte into the limiting component 3 under the capillary action and diffuse inside the limiting component 3 to leave the electrolyte in the limiting component 3, so that the volume of the limiting component 3 expands. When subjected to external extrusion, or the electrolyte of the external environment is lower than the electrolyte left in the liquid absorbing member, the electrolyte can be released to the outside or the electrode body in contact with the limiting component 3 to soak the electrode assembly 2.

[0111] In these alternative embodiments, the limiting component 3 is configured to absorb the expansion of the electrolyte, which can not only reduce the mechanical damage to the electrode assembly 2, but also absorb and release the electrode assembly 2, soak the electrode assembly 2, and improve the cycle performance of the battery cell 10.

[0112] According to an embodiment of the present application, the limiting component 3 is configured to increase the volume to 130% to 200% after absorbing the electrolyte.

[0113] In some embodiments of the present application, the limiting component 3 is configured to absorb the volume increase of the electrolyte to 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, 200%, or within other ranges consisting of any two endpoints of the above.

[0114] In these optional embodiments, the volume expansion can effectively fill the gaps inside the battery and improve the defects of uneven gaps.

[0115] According to an embodiment of the present application, the limiting component 3 is attached to at least one of the housing 1 and the electrode assembly 2.

[0116] In embodiments of the present application, the limiting component 3 is attached to at least one of the housing 1 and the electrode assembly 2. It can be understood that the limiting component 3 can be attached only to the housing 1; or the limiting component 3 can be attached only to the electrode assembly 2, and part of the limiting component 3 is located at the end of the first active material layer 213 along the first direction x; or one part of the limiting component 3 is attached to the housing 1, and another part of the limiting component 3 is attached to the electrode assembly 2.

[0117] In these optional embodiments, the limiting component 3 is attached to at least one of the housing 1 and the electrode assembly 2 to improve the connection stability of the limiting component 3.

[0118] For reference Figure 7 , Figure 7 is a partial structural schematic diagram of an electrode assembly of a battery cell provided by an embodiment of the present application.

[0119] According to an embodiment of the present application, as shown in Figure 6 and Figure 7 , the first active material layer 213 includes a first base body 2131 and a first thinned portion 2132 arranged along the first direction x, and the thickness of the first thinned portion 2132 is less than or equal to the thickness of the first base body 2131. In the thickness direction z of the battery cell 10, at least part of the limiting component 3 is located between the first thinned portion 2132 and the housing 1.

[0120] The first active material layer 213 includes a first base 2131 and a first thinned portion 2132 connected to the first base 2131, the first thinned portion 2132 is located at an end of the first base 2131 along the first direction x, and the thickness of the first thinned portion 2132 is smaller than the thickness of the first base 2131. The first thinned portion 2132 is a thinned region formed at the end of the first active material layer 213. Therefore, the thinned region increases the gap between the first active material layer 213 and the separator 23 at the end, and the increased gap prolongs the transmission path of the active ions, which results in larger polarization and causes ion precipitation.

[0121] Exemplarily, along the first direction x, the thickness of the first thinned portion 2132 gradually decreases in a direction away from the first base 2131.

[0122] In these optional embodiments, at least part of the limiting component 3 is located between the first thinned portion 2132 and the shell 1 in the thickness direction z of the battery monomer 10, that is, at least part of the limiting component 3 is arranged opposite to the first thinned portion 2132. Not only can it reduce the difference in the gap between the middle region and the end region along the first direction x, but also can press the gap between the first active material layer 213 and the separator 23 at the end, shorten the transmission path of the active ions, thereby improving the ion precipitation phenomenon and improving the reliability of the battery monomer 10.

[0123] According to an embodiment of the present application, the projection of the limiting component 3 along the thickness direction z covers the projection of the first thinned portion 2132 along the thickness direction z.

[0124] In the embodiments of the present application, the projection of the limiting component 3 along the thickness direction z covers the projection of the first thinned portion 2132 along the thickness direction z, that is, in the first direction x, at least one end of the limiting component 3 exceeds the first thinned portion 2132.

[0125] Optionally, in the first direction x, both ends of the limiting component 3 exceed the first thinned portion 2132.

[0126] In these optional embodiments, the larger degree of reducing the gap unevenness of the battery monomer 10 causes the ion precipitation defect.

[0127] According to an embodiment of the present application, as shown in Figure 6 and Figure 7 The battery monomer 10 includes at least two limiting components 3 arranged at intervals along the first direction x, wherein, in the thickness direction z, at least one limiting component 3 is arranged opposite to the first thinned portion 2132, and at least one limiting component 3 is arranged opposite to the end of the first base 2131 along the first direction x and away from the first thinned portion 2132.

[0128] In the embodiments of the present application, the thickness of the first thinned portion 2132 and the first base body 2131 after expansion is not completely uniform along the first direction x and away from the end of the first thinned portion 2132, so that the corresponding limiting component 3 can be designed according to the actual gap at the position of the first thinned portion 2132, and the actual gap at the position of the first base body 2131 along the first direction x and away from the end of the first thinned portion 2132, so that the overall gap can be more uniform.

[0129] Exemplarily, the battery cell 10 includes a first limiting component and a second limiting component arranged along the first direction x, and in the thickness direction z, the projection area of the first limiting component on the electrode assembly 2 can be equal to or different from the projection area of the second limiting component on the electrode assembly 2. The first limiting component is arranged opposite to the first thinned portion 2132, and the second limiting component is arranged opposite to the end of the first base body 2131 along the first direction x and away from the first thinned portion 2132.

[0130] Optionally, the projection area of the first limiting component on the pole piece body 211 is different from the projection area of the second limiting component on the pole piece body 211.

[0131] Optionally, the projection area of the first limiting component on the pole piece body 211 is equal to the projection area of the second limiting component on the pole piece body 211.

[0132] In these optional embodiments, a plurality of limiting components 3 are arranged along the first direction x, so that the limiting components 3 match the two ends of the first base body 2131 along the first direction x, limiting the uneven expansion of the middle region and the two end regions of the electrode assembly 2.

[0133] According to one embodiment of the present application, as shown in Figure 6 and Figure 7 The electrode assembly 2 further includes a second pole piece 22 and a separator 23, the separator 23 is used to separate the first pole piece 21 and the second pole piece 22, the polarities of the first pole piece 21 and the second pole piece 22 are opposite, and the first pole piece 21, the separator 23 and the second pole piece 22 are wound to form a bending region 24 and a flat region 25 connected to the bending region 24. In the thickness direction z, at least part of the limiting component 3 is arranged opposite to the flat region 25.

[0134] In the embodiments of the present application, the first pole piece 21, the separator 23 and the second pole piece 22 are wound along the winding axis to form a winding structure. In the winding structure, the first pole piece 21, the separator 23 and the second pole piece 22 are arranged vertically and superimposed, and the first pole piece 21, the separator 23 and the second pole piece 22 are wound into multiple turns along the winding direction, and the winding direction is the direction of the first pole piece 21, the separator 23 and the second pole piece 22 winding from inside to outside in a circumferential direction. The winding direction can be counterclockwise or clockwise.

[0135] The electrode assembly 2 with the winding structure includes a flat area 25 and bending areas 24 located at both ends of the flat area 25.

[0136] The flat area 25 refers to an area with a parallel structure in the winding structure, that is, the first electrode tab 21, the separator 23 and the second electrode tab 22 in the flat area 25 are substantially parallel to each other, that is, the surface of each layer of the first electrode tab 21, the separator 23 and the second electrode tab 22 of the electrode assembly 2 in the flat area 25 is a plane.

[0137] The bending area 24 refers to an area with a bending structure in the winding structure, that is, the first electrode tab 21, the separator 23 and the second electrode tab 22 in the bending area 24 are all bent, that is, the surface of each layer of the first electrode tab 21, the separator 23 and the second electrode tab 22 of the electrode assembly 2 in the bending area 24 is a curved surface.

[0138] The limiting component 3 is at least partially arranged opposite to the flat area 25, which can be understood as that the limiting component 3 is at least partially arranged opposite to the end of the electrode tab main body 211 along the first direction x in the flat area 25.

[0139] In the embodiments of the present application, the limiting component 3 is at least partially arranged opposite to the flat area 25, which can be understood as that the limiting component 3 includes a first part and a second part, the first part is arranged opposite to the flat area 25, and the second part is arranged opposite to the bending area 24; or, the limiting component 3 is only arranged opposite to the flat area 25.

[0140] In these alternative embodiments, the limiting component 3 is at least partially arranged opposite to the flat area 25, which is beneficial to the limiting component 3 to extrude the end of the electrode tab main body 211 along the first direction x in a large area, thereby reducing the phenomenon of uneven gap and more effectively improving the ion precipitation phenomenon.

[0141] According to one embodiment of the present application, as shown in Figure 6 in the thickness direction z, the limiting component 3 is also arranged opposite to the bending area 24.

[0142] Exemplarily, the limiting component 3 includes a first part and a second part, the first part is arranged at one end of the second part and connected to the second part, in the thickness direction z, the first part is arranged opposite to the flat area 25, and the second part is arranged opposite to the bending area 24.

[0143] In these alternative embodiments, the limiting component 3 is arranged opposite to the flat area 25 and the bending area 24, and the limiting component 3 as a whole has a large span, which can effectively reduce the defect of uneven gap on the one hand, and reduce the occurrence of stress concentration on the other hand.

[0144] According to one embodiment of the present application, as shown in Figure 6 and Figure 7As shown, the second tab 22 includes a second active material layer 221, the second active material layer 221 including a second base 2211 and a second thinned portion 2212 arranged along the first direction x, the second thinned portion 2212 having a thickness less than or equal to a thickness of the second base 2211.

[0145] In particular, the second tab 22 includes a second current collector and a second active material layer 221 disposed on a surface of the second current collector, the second active material layer 221 including a second base 2211 and a second thinned portion 2212 connected to the second base 2211, the second thinned portion 2212 being located at an end of the second base 2211 along the first direction x, the second base 2211 having a thickness less than a thickness of the second base 2211. The second thinned portion 2212 is a thinned region formed at the end of the second active material layer 221.

[0146] Exemplarily, the thinned region at the end of the second active material layer 221 is at least partially oppositely disposed with the thinned region at the end of the first active material layer 213, i.e., the second thinned portion 2212 is at least partially oppositely disposed with the first thinned portion 2132, at this time, the first thinned portion 2132 and the second thinned portion 2212 are both disposed at one end of the electrode assembly 2, at least part of the limiting member 3 is oppositely disposed with the first thinned portion 2132, and the part of the limiting member 3 oppositely disposed with the first thinned portion 2132 can also be oppositely disposed with the second thinned portion 2212.

[0147] Exemplarily, the thinned region at the end of the second active material layer 221 is oppositely disposed with the thinned region at the end of the first active material layer 213, i.e., the first thinned portion 2132 and the second thinned portion 2212 are disposed at opposite ends of the electrode assembly 2, one part of the limiting member 3 is oppositely disposed with the first thinned portion 2132, and another part of the limiting member 3 is oppositely disposed with the second thinned portion 2212, the first part and the second part being spaced apart.

[0148] According to one embodiment of the present application, in the thickness direction z, the second thinned portion 2212 is at least partially oppositely disposed with the first thinned portion 2132, and the limiting member 3 is at least partially oppositely disposed with the second thinned portion 2212.

[0149] In the embodiments of the present application, the second thinned portion 2212 is at least partially disposed opposite the first thinned portion 2132 in the thickness direction z. It can be understood that the first thinned portion 2132 and the second thinned portion 2212 are both disposed at one end of the electrode assembly 2, at least part of the limiting member 3 is disposed opposite the first thinned portion 2132, at least part of the limiting member 3 is disposed opposite the second thinned portion 2212, that is, at least part of the limiting member 3 is disposed opposite the first thinned portion 2132 and the second thinned portion 2212. It can be understood that the projection of the first thinned portion 2132 along the thickness direction z on the first base body 2131, the projection of the second thinned portion 2212 along the thickness direction z on the first base body 2131, and the projection of the limiting member 3 along the thickness direction z on the first base body 2131 at least partially coincide.

[0150] In these optional embodiments, the second thinned portion 2212 is at least partially disposed opposite the first thinned portion 2132, and at least part of the limiting member 3 is disposed opposite the first thinned portion 2132 and the second thinned portion 2212. One limiting member 3 can reduce the gap between the first thinned portion 2132 and the spacer 23, the gap between the second thinned portion 2212 and the spacer 23, and the defect of uneven overall gap, not only can improve the ion precipitation phenomenon, but also can further improve the overall layout compactness inside the battery monomer 10.

[0151] According to one embodiment of the present application, in the thickness direction z, the projection of the limiting member 3 covers the projection of the first thinned portion 2132 and the projection of the second thinned portion 2212.

[0152] Specifically, in the first direction x, the limiting member 3 has opposite first and second ends, and the first and second ends extend beyond the first thinned portion 2132 and the second thinned portion 2212.

[0153] According to one embodiment of the present application, the second thinned portion 2212 is located at one end of the second base body 2211 away from the first thinned portion 2132 in the first direction x. The battery monomer 10 includes at least two limiting members 3 spaced apart in the first direction x, wherein in the thickness direction z, at least one limiting member 3 is disposed opposite the first thinned portion 2132, and at least one limiting member 3 is disposed opposite the second thinned portion 2212.

[0154] In the embodiments of the present application, the second thinning portion 2212 is located at one end of the second base 2211 away from the first thinning portion 2132 in the first direction x. It can be understood that the thinning region of the end of the second active material layer 221 is arranged in a staggered manner with the thinning region of the end of the first active material layer 213, that is, the first thinning portion 2132 and the second thinning portion 2212 are arranged at opposite ends of the electrode assembly 2. The first direction x is parallel to the direction in which the first base 2131 points to the first thinning portion 2132, that is, the direction in which the second base 2211 points to the second thinning portion 2212 is parallel to the direction in which the first base 2131 points to the first thinning portion 2132.

[0155] Specifically, the battery cell 10 includes a plurality of limiting components 3, the plurality of limiting components 3 including a first limiting component and a second limiting component, the first limiting component and the second limiting component being arranged in a spaced manner along the first direction x, the projection area of the first limiting component on the first base 2131 portion and the projection area of the second limiting component on the second base portion can be equal or unequal.

[0156] In these optional embodiments, at least one limiting component 3 is arranged opposite to the first thinning portion 2132, and at least one limiting component 3 is arranged opposite to the second thinning portion 2212, so that in addition to reducing the defect of uneven gap, the limiting component 3 also has a lower number of components and a lower quality.

[0157] According to one embodiment of the present application, as shown in Figure 4 In the first direction x, the distance M of the limiting component 3 and the distance L of the electrode assembly 2 along the first direction x satisfy: 0.03L≤M≤0.3L.

[0158] Exemplarily, in the first direction x, the limiting component 3 is arranged opposite to the first thinning portion 2132, and the distance M of the limiting component 3 and the distance L of the electrode assembly 2 along the first direction x satisfy: 0.15L≤M≤0.3L.

[0159] Exemplarily, in the first direction x, the limiting component 3 is arranged opposite to the end of the tab body 211 along the first direction x and away from the first thinning portion 2132, and the distance M of the limiting component 3 and the distance L of the electrode assembly 2 along the first direction x satisfy: 0.03L≤M≤0.15L.

[0160] In these optional embodiments, the limiting component 3 has a suitable distance in the first direction x, thereby effectively inhibiting the swelling deformation of the electrode assembly 2, and also reducing the influence on the margin of the electrode assembly 2.

[0161] According to one embodiment of the present application, as shown in Figure 6 The limiting component 3 at least surrounds one turn of the electrode assembly 2.

[0162] Exemplarily, the limiting component 3 is adhered to the outermost circle of the electrode assembly 2 in one circle around the electrode assembly 2.

[0163] In these alternative embodiments, the limiting component 3 is arranged in one circle around the electrode assembly 2, so that the distance between the housing 1 and the end of the electrode assembly 2 is uniform, the electrode assembly 2 can be properly limited, the electrode assembly 2 is reduced, and the reliability of the battery monomer 10 is improved.

[0164] According to one embodiment of the present application, the limiting component 3 is arranged on the opposite sides of the electrode assembly 2 in the thickness direction z of the battery monomer 10.

[0165] Exemplarily, the battery monomer 10 has a predetermined length and width and is in a rectangular structure, and the battery monomer 10 includes four limiting components 3, two of which are arranged opposite to each other in the length direction, and the other two are arranged opposite to each other in the thickness direction z.

[0166] In these alternative embodiments, the limiting component 3 arranged on the opposite sides of the electrode assembly 2 neither occupies too much space nor suppresses the expansion of the electrode assembly on both sides of the electrode assembly 2, so as to improve the uneven gap phenomenon.

[0167] According to one embodiment of the present application, the limiting component 3 is made of oriented polystyrene.

[0168] Exemplarily, the oriented polystyrene is configured to absorb the electrolyte expansion. The thickness of the limiting component 3 after absorbing the electrolyte expansion is 20 μm to 100 μm.

[0169] In these alternative embodiments, the oriented polystyrene expansion adhesive can be tightly bonded with the housing 1, the electrode assembly 2, etc., so as to improve the overall structural stability of the battery and reduce the relative displacement and looseness between components. The oriented polystyrene expansion adhesive has good chemical corrosion resistance, strong electrolyte resistance, and can maintain stable performance in the battery.

[0170] In a second aspect, the present application provides a battery device including the battery monomer 10 according to the foregoing.

[0171] In a third aspect, the present application provides a power utilization device including the battery monomer 10 according to the foregoing or the battery device according to the foregoing, and the battery monomer 10 or the battery device is used for storing or providing electric energy.

[0172] According to some embodiments of the present application, referring to Figure 3 to Figure 6 , the present application provides a battery monomer 10 including a housing 1, an electrode assembly 2, two limiting components 3, and an electrolyte.

[0173] The housing 1 has a receiving cavity 11.

[0174] The electrolyte is accommodated in the accommodation cavity 11.

[0175] The limiting member 3 is a flexible limiting member configured to absorb the expansion of the electrolyte. The limiting member 3 is configured to absorb the volume increase of 130% to 200% after absorbing the electrolyte. The limiting member 3 is attached to the electrode assembly 2 and surrounds one turn of the electrode assembly 2. The material of the limiting member 3 is oriented polystyrene.

[0176] The electrode assembly 2 is disposed in the accommodation cavity 11, and the electrode assembly 2 further includes a second tab 22 and a separator 23 for separating the first tab 21 and the second tab 22, the polarities of the first tab 21 and the second tab 22 being opposite. The first tab 21 includes a tab body 211 disposed in a first direction x and a tab ear 212, at least part of the tab body 211 being provided with a first active material layer 213, and at least part of the tab ear 212 being not provided with the first active material layer 213. The first active material layer 213 includes a first base 2131 and a first thinned portion 2132 disposed in the first direction x, the thickness of the first thinned portion 2132 being less than or equal to the thickness of the first base 2131. In the thickness direction z of the battery cell 10, one limiting member 3 is located between the first thinned portion 2132 and the case 1, and the projection of the limiting member 3 covers the projection of the first thinned portion 2132. The second tab 22 includes a second active material, and a second active material layer 221 includes a second base 2211 and a second thinned portion 2212 disposed in the first direction x, the thickness of the second thinned portion 2212 being less than or equal to the thickness of the second base 2211. The second thinned portion 2212 is located at an end of the second base 2211 away from the first thinned portion 2132 in the first direction x. In the thickness direction z of the battery cell 10, the other limiting member 3 is located between the second thinned portion 2212 and the case 1, and the projection of the limiting member 3 covers the projection of the second thinned portion 2212. The first direction x is perpendicular to the thickness direction z.

[0177] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it without departing from the scope of the application, and components thereof can be replaced with equivalents, especially, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly is disposed within the receiving cavity. The electrode assembly includes a first electrode plate, the first electrode plate including an electrode plate body and an electrode tab disposed along a first direction, at least a portion of the electrode plate body being provided with a first active material layer, and at least a portion of the electrode tab not being provided with the first active material layer. A limiting member is provided, at least a portion of which is disposed between the end of the first active material layer along the first direction and the outer casing in the thickness direction of the battery cell, wherein the thickness direction of the battery cell is perpendicular to the first direction.

2. The battery cell according to claim 1, characterized in that, The limiting component is a flexible limiting component.

3. The battery cell according to claim 1, characterized in that, The battery cell also includes an electrolyte, which is contained in the receiving cavity; The limiting component is configured to absorb the expansion of the electrolyte.

4. The battery cell according to claim 3, characterized in that, The limiting component is configured to increase in volume by 130% to 200% after absorbing the electrolyte.

5. The battery cell according to claim 1, characterized in that, The limiting component is attached to at least one of the housing and the electrode assembly.

6. The battery cell according to claim 1, characterized in that, The first active material layer includes a first substrate and a first thinned portion arranged along the first direction, wherein the thickness of the first thinned portion is less than or equal to the thickness of the first substrate; In the thickness direction of the battery cell, at least a portion of the limiting member is located between the first thinned portion and the outer casing.

7. The battery cell according to claim 6, characterized in that, The projection of the limiting component along the thickness direction covers the projection of the first thinned portion along the thickness direction.

8. The battery cell according to claim 6, characterized in that, The battery cell includes at least two limiting components spaced apart along the first direction. In the thickness direction, at least one of the limiting components is disposed opposite to the first thinning portion, and at least one of the limiting components is disposed opposite to the end of the first substrate along the first direction and away from the first thinning portion.

9. The battery cell according to claim 6, characterized in that, The electrode assembly further includes a second electrode and a separator, the separator being used to isolate the first electrode and the second electrode, the first electrode and the second electrode having opposite polarities, the first electrode, the separator and the second electrode being wound to form a bent region and a straight region connected to the bent region; In the thickness direction, at least a portion of the limiting member is disposed opposite to the straight region.

10. The battery cell according to claim 9, characterized in that, In the thickness direction, the limiting member is also disposed opposite to the bending area.

11. The battery cell according to claim 9, characterized in that, The second electrode includes a second active material layer, which includes a second substrate and a thinned portion arranged along the first direction. The thickness of the second thinned portion is less than or equal to the thickness of the second substrate.

12. The battery cell according to claim 11, characterized in that, In the thickness direction, the second thinning portion is at least partially disposed opposite to the first thinning portion, and the limiting member is at least partially disposed opposite to the second thinning portion.

13. The battery cell according to claim 11, characterized in that, In the thickness direction, the projection of the limiting member covers the projection of the first thinned portion and the projection of the second thinned portion.

14. The battery cell according to claim 11, characterized in that, The second thinned portion is located at the end of the second substrate away from the first thinned portion in the first direction; The battery cell includes at least two limiting components spaced apart along the first direction. In the thickness direction, at least one of the limiting components is disposed opposite to the first thinning portion, and at least one of the limiting components is disposed opposite to the second thinning portion.

15. The battery cell according to claim 1, characterized in that, In the first direction, the dimension M of the limiting component and the dimension L of the electrode assembly in the first direction satisfy: 0.03L≤M≤0.3L.

16. The battery cell according to claim 1, characterized in that, The limiting component surrounds the electrode assembly at least once.

17. The battery cell according to claim 1, characterized in that, The limiting components are provided on both opposite sides of the electrode assembly in the thickness direction of the battery cell.

18. The battery cell according to claim 1, characterized in that, The limiting component is made of oriented polystyrene.

19. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1 to 18.

20. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1 to 18 or a battery device according to claim 19, wherein the battery cell or the battery device is used to store or provide electrical energy.

Images