Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment, the battery monomer comprises a shell, an electrode assembly and a barrier, the electrode assembly is arranged in the shell, the electrode assembly comprises an electrode main body and an active material layer arranged on the electrode main body, the active material layer comprises a main body area and a thinning area which are arranged along a first direction, and the main body area is arranged in the first direction. The thickness of the active material layer in the main body region is larger than that in the thinned region, the electrode assembly comprises a first region and a second region which are arranged in the first direction, the main body region is located in the first region, and the thinned region is located in the second region; the barrier is arranged between the second area and the shell, at least part of the barrier extends in the circumferential direction of the electrode assembly, the thickness of the barrier in the second direction is in an increasing trend in the direction from the first area to the second area, and the first direction intersects with the second direction. The battery monomer provided by the embodiment of the utility model can improve the cycle performance and improve the reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery monomer, a battery device and an electric equipment. BACKGROUND

[0002] With the development of new energy technology, batteries are increasingly widely used, for example, in mobile phones, notebook computers, electric cars, electric vehicles, electric aircraft, electric ships, electric toy cars, electric toy ships, electric toy aircraft and electric tools.

[0003] The development of battery technology needs to consider various design factors, for example, how to improve the cycle performance and service life of the battery monomer, which is an important research direction in the field of batteries. CONTENT OF THE INVENTION

[0004] The present application provides a battery monomer, a battery device and an electric equipment, which can improve the cycle performance and prolong the service life.

[0005] In a first aspect, the present application provides a battery monomer, comprising a shell, an electrode assembly and a barrier; the electrode assembly is arranged in the shell, and the electrode assembly comprises an electrode body and an active material layer arranged on the electrode body; the active material layer comprises a main body area and a thinning area arranged along a first direction; the thickness of the active material layer in the main body area is greater than that in the thinning area; the electrode assembly comprises a first area and a second area arranged along the first direction; the main body area is located in the first area, and the thinning area is located in the second area; the barrier is arranged between the second area and the shell and extends at least partially along the circumference of the electrode assembly; in the direction from the first area to the second area, the thickness of the barrier in a second direction increases; and the first direction intersects the second direction.

[0006] In the technical solution of the present application, the battery monomer comprises a shell, an electrode assembly arranged in the shell and a barrier arranged around the electrode assembly; the electrode assembly comprises an electrode body and an active material layer arranged on the electrode body; due to the influence of factors such as processing technology, the active material layer usually has a thin thickness at one end close to the tab of the electrode sheet, that is, a main body area and a thinning area are formed; therefore, the electrode assembly formed by stacking or winding the electrode sheet also has a first area and a second area with different thicknesses. The barrier is arranged corresponding to the thinning area of the active material layer, which can fill the gap formed between the electrode assembly and the shell due to the change in thickness of the electrode assembly, reduce the possibility of lithium precipitation in the cycle process due to the existence of the gap, thereby improving the cycle performance and prolonging the service life of the battery monomer.

[0007] According to some of the embodiments of the present application, along the direction from the second region to the first region, the second region comprises the first sub-region, the second sub-region and the third sub-region arranged in sequence, in the second direction, the maximum dimension of the barrier in the first sub-region is L1, in the second sub-region is L2, and in the third sub-region is L3; L1≥L2≥L3. The barrier is at least partially arranged in the first sub-region, and the thickness gradually changes, which is easy to adapt to the electrode assembly.

[0008] According to some of the embodiments of the present application, along the first direction, both ends of the barrier extend to the first sub-region and the third sub-region, and the dimension of the barrier is 7mm-13mm. The barrier has a suitable width.

[0009] According to some of the embodiments of the present application, the first sub-region, the second sub-region and the third sub-region are arranged in sequence in the first direction, the spacing between the second sub-region and the side edge of the second region away from the first region is 2mm-4mm, and the spacing between the third sub-region and the side edge of the second region away from the first region is 7mm-9mm; in the second direction, the dimension of the electrode assembly in the first region is L4, 0.06≤L1 / L4≤0.1, 0.04≤L2 / L4≤0.06, and 0.02≤L3 / L4≤0.03. The thickness of the barrier changes gently, which is easy to adapt to the electrode assembly.

[0010] According to some of the embodiments of the present application, the barrier is annular and surrounds the electrode assembly; or the barrier comprises a plurality of first sub-components arranged in sequence along the circumference of the electrode assembly. The barrier can adopt a plurality of different structural forms.

[0011] According to some of the embodiments of the present application, the barrier is annular and surrounds the electrode assembly, and the inner side surface of the barrier abuts against the outer circumferential surface of the second region to extrude and compress the electrode assembly; the barrier is made of elastic material, and the elastic modulus of the barrier is 0.05Mpa-1Mpa. The barrier has elasticity and can bundle the electrode assembly, and further eliminates the gap inside the electrode assembly.

[0012] According to some of the embodiments of the present application, the barrier is annular and surrounds the electrode assembly, and along the first direction, the dimension of the barrier is the same as that of the second region; or the barrier is annular and at least part of the barrier comprises a plurality of second sub-components arranged at intervals in the first direction. The barrier can continuously extend in the first direction or comprise a plurality of second sub-components arranged at intervals.

[0013] According to some embodiments of the present application, the barrier piece includes a plurality of first sub-pieces, the plurality of first sub-pieces are arranged at intervals in the circumferential direction of the electrode assembly, and opposite side surfaces of each first sub-piece are respectively in abutment with the electrode assembly and the shell. The barrier piece can also include a plurality of first sub-pieces arranged at intervals in the circumferential direction of the electrode assembly, and the barrier piece exerts a pressing force on the electrode assembly by abutting the shell and the electrode assembly on two opposite sides.

[0014] According to some embodiments of the present application, the battery cell includes a plurality of electrode assemblies and a plurality of barrier pieces, and the plurality of electrode assemblies and the plurality of barrier pieces are arranged in one-to-one correspondence. This facilitates reducing the gap inside the electrode assembly and reducing the possibility of damage or wrinkling of the electrode tab.

[0015] According to some embodiments of the present application, the material of the barrier piece includes polyethylene terephthalate. This makes the barrier piece have high reliability and facilitates processing and molding.

[0016] In a second aspect, the present application provides a battery device, which includes a shell and the battery cell of any one of the first aspect.

[0017] In a third aspect, the present application provides a use-electricity device, which includes the battery device of any one of the second aspect, and the battery device is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals in the drawings indicate the same or similar elements. In the drawings:

[0019] Figure 1 A simple schematic diagram of a vehicle is provided for some embodiments of the present application;

[0020] Figure 2 An exploded schematic diagram of a battery device is provided for some embodiments of the present application;

[0021] Figure 3 An exploded schematic diagram of a battery cell is provided for some embodiments of the present application;

[0022] Figure 4 A cross-sectional structural schematic diagram of a battery cell is provided for some embodiments of the present application;

[0023] Figure 5 A cross-sectional structural schematic diagram of a battery cell is provided for some embodiments of the present application; Figure 4 A cross-sectional view of the A-A' shown;

[0024] Figure 6Partial structural schematic view of an electrode assembly provided for some embodiments of the present application;

[0025] Figure 7 Partial cross-sectional structural schematic view of a battery cell provided for some embodiments of the present application;

[0026] Figure 8 Cross-sectional structural schematic view of a battery cell provided for some embodiments of the present application;

[0027] Figure 9 Partial cross-sectional structural schematic view of a battery cell provided for some embodiments of the present application;

[0028] Figure 10 Cross-sectional structural schematic view of a battery cell provided for some embodiments of the present application.

[0029] Reference Signs:

[0030] 1000 - vehicle;

[0031] 100 - battery cell; 200 - battery device; 300 - controller; 400 - motor;

[0032] 10 - case; 20 - electrode assembly; 30 - barrier; 40 - box;

[0033] 21 - electrode main body; 22 - active material layer; 23 - first region; 24 - second region; 31 - first sub member; 32 - second sub member; 41 - first box portion; 42 - second box portion; 43 - accommodation portion;

[0034] 221 - main body region; 222 - thinned region; 241 - first sub region; 242 - second sub region; 243 - third sub region;

[0035] X - first direction; Y - second direction. DETAILED DESCRIPTION

[0036] Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein 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.

[0038] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise explicitly specified and limited.

[0039] Reference herein to "embodiments" means that the particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily a separate or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0041] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two), and similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0042] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application.

[0043] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0044] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0045] The battery cell 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., and the present application is not limited thereto.

[0046] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, and can prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0047] In some embodiments, the positive electrode can be a positive electrode sheet, which can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0048] As an example, the positive electrode current collector has two opposite surfaces in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0049] As an example, the positive electrode current collector can be a metal foil or a composite current collector.

[0050] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0051] As an example, the negative electrode current collector can be a metal foil, a foam metal, or a composite current collector.

[0052] As an example, the negative electrode sheet can include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0053] As an example, the negative electrode current collector has two opposite surfaces in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0054] As an example, the negative electrode active material can be a negative electrode active material known in the art for use in a battery cell. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0055] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0056] In some embodiments, the electrode assembly further comprises a separator disposed between the positive electrode and the negative electrode.

[0057] In some embodiments, the separator is a separator film. The type of separator film is not particularly limited in the present application, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0058] For example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic.

[0059] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0060] In some embodiments, the battery cell further comprises an electrolyte, which functions to conduct ions between the positive electrode and the negative electrode. The type of electrolyte is not particularly limited in the present application, and can be selected as needed. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0061] In some embodiments, the electrode assembly is provided with a tab, which can guide current out of the electrode assembly. The tab includes a positive tab and a negative tab.

[0062] In some embodiments, the battery cell can comprise a housing. The housing is used to package components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0063] In some embodiments, the housing can be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect with the electrode assembly for outputting or inputting the electrical energy of the battery cell.

[0064] For example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, and 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., and the present application is not particularly limited.

[0065] The battery device referred to in the embodiments of the present application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0066] In some embodiments, the battery device can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0067] In some embodiments, the battery device can be a battery pack, which includes a box and battery cells or modules housed in the box.

[0068] In some embodiments, the box can be part of a chassis structure of a vehicle. For example, part of the box can be part of a floor of the vehicle, or part of the box can be part of a cross beam and a longitudinal beam of the vehicle.

[0069] In some embodiments, the battery device can be an energy storage device. The energy storage device can include an energy storage container, an energy storage cabinet, etc.

[0070] A battery cell generally includes a casing, and an electrode assembly, an electrolyte, etc. disposed in the casing. The electrode assembly generally includes a positive electrode tab, a negative electrode tab, and a separator for forming an insulation structure between the two. The positive electrode tab and the negative electrode tab are generally formed by coating an active material on a foil as an electrode main body, i.e., the tab generally includes an electrode main body and an active material layer.

[0071] In a conventional battery cell manufacturing process, a slurry containing an active material is coated on a foil when preparing a tab, and the slurry edge position is generally thinned to reduce the possibility of tab edge swelling caused by baking and casting. As a result, the active material layer formed on the tab finally has a thinned area with a relatively thin thickness.

[0072] On this basis, the applicant found that, due to the existence of areas with different thicknesses in the tab, the electrode assembly formed by winding or stacking the tab generally has areas with different thicknesses, and the thinner part is prone to have a gap with the casing containing the electrode assembly during the cycle, thereby causing edge lithium precipitation at the gap.

[0073] In view of this, the embodiments of the present application provide a technical solution which fills the gap between the casing and the electrode assembly by setting a barrier therebetween, thereby improving the cycle performance of the battery cell and prolonging the service life.

[0074] The technical solution described in the embodiments of the present application is applicable to a battery device and an electric device using the battery device. The electric device is, for example, a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric automobile, a ship, a spacecraft, an electric toy, and an electric tool, etc. The spacecraft is, for example, an airplane, a rocket, a space shuttle, a spacecraft, etc. The electric toy includes, for example, a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric airplane toy, etc. The electric tool includes, for example, a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, and an electric planer.

[0075] The battery cell described in the embodiments of the present application is not only limited to the above-described electric device, but for the sake of brevity, the following embodiments are described with the electric vehicle as an example.

[0076] Please refer to Figure 1 , Figure 1 A simple schematic diagram of a vehicle is provided for some embodiments of the present application. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, which can be a pure electric vehicle, a hybrid vehicle, or an extended range vehicle, etc. The vehicle 1000 can be provided with a battery device 200, for example, at the bottom, the front or the rear of the vehicle 1000. The battery device 200 can be used for power supply of the vehicle 1000, for example, the battery device 200 can be used as the operating power supply of the vehicle 1000. The vehicle 1000 can also include a controller 300 and a motor 400, and the controller 300 is used to control the power supply of the motor 400 by the battery. The battery device 200 can be used for starting, navigation, etc. of the vehicle 1000, of course, the battery can also be used to drive the vehicle 1000 to run, instead of or partially instead of fuel or natural gas to provide driving for the vehicle 1000.

[0077] Figure 2 An explosion schematic diagram of the battery device is provided for some embodiments of the present application. As shown in Figure 2 The battery device includes a box body and a battery cell, and the battery cell is contained in the box body.

[0078] The box body 40 is used to contain the battery cell 100, and the box body 40 can be of various structures. In some embodiments, the box body 40 can include a first box body part 41 and a second box body part 42, the first box body part 41 and the second box body part 42 are mutually covered, and the first box body part 41 and the second box body part 42 jointly define a containing part 43 for containing the battery cell 100. The second box body part 42 can be a hollow structure with one end open, and the first box body part 41 is a plate-like structure, which is covered on the open side of the second box body part 42 to form the box body 40 with the containing part 43; the first box body part 41 and the second box body part 42 can also be hollow structures with one side open, and the open side of the first box body part 41 is covered on the open side of the second box body part 42 to form the box body 40 with the containing part 43. Of course, the first box body part 41 and the second box body part 42 can be of various shapes, such as a cylinder, a cuboid, etc.

[0079] In the battery, the battery cell 100 can be one or multiple. If the battery cell 100 is multiple, the multiple battery cells 100 can be connected in series, in parallel or in a mixed manner. The mixed manner means that the multiple battery cells 100 are connected in series and in parallel. The multiple battery cells 100 can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery cells 100 is accommodated in the box 40. Of course, the multiple battery cells 100 can be first connected in series, in parallel or in a mixed manner to form a battery module, and then the multiple battery modules are connected in series, in parallel or in a mixed manner to form a whole and are accommodated in the box 40.

[0080] In some embodiments, the battery cell 100 is multiple, and the multiple battery cells 100 are first connected in series, in parallel or in a mixed manner to form a battery module. Then, the multiple battery modules are connected in series, in parallel or in a mixed manner to form a whole and are accommodated in the box 40.

[0081] Next, the structure of the battery cell 100, the battery device 200 and the electric equipment will be described with reference to the accompanying drawings. Figure 3 to the accompanying drawings. Figure 10 The structure of the battery cell 100, the battery device 200 and the electric equipment will be described.

[0082] Please refer to the accompanying drawings. Figures 3 to 6 , Figure 3 The explosion schematic diagram of the battery cell provided in some embodiments of the present application, Figure 4 The cross-sectional structure schematic diagram of the battery cell provided in some embodiments of the present application, Figure 5 The cross-sectional structure schematic diagram of the battery cell provided in some embodiments of the present application, Figure 4 The cross-sectional view of the A-A' shown in the figure, Figure 6 The partial structure schematic diagram of the electrode assembly provided in some embodiments of the present application.

[0083] In a first aspect, the present application provides a battery cell 100, comprising a shell, an electrode assembly 20 and a barrier 30. The electrode assembly 20 is arranged in the shell. The electrode assembly 20 comprises an electrode body 21 and an active material layer 22 arranged on the electrode body 21. The active material layer 22 comprises a main body area 221 and a thinning area 222 arranged along a first direction X. The thickness of the active material layer 22 in the main body area 221 is greater than that in the thinning area 222. The electrode assembly 20 comprises a first area 23 and a second area 24 arranged along the first direction X. The main body area 221 is located in the first area 23, and the thinning area 222 is located in the second area 24. The barrier 30 is arranged between the second area 24 and the shell and extends at least partially along the circumference of the electrode assembly 20. In the direction from the first area 23 to the second area 24, the thickness of the barrier 30 in a second direction Y shows an increasing trend. The first direction X intersects the second direction Y.

[0084] The embodiment of the present application provides a battery monomer 100, which comprises a shell 10 for providing accommodation, protection and support and an electrode assembly 20 for realizing electrical functions, the shell 10 encloses an accommodation cavity, the electrode assembly 20 is arranged in the accommodation cavity, and an electrolyte can also be arranged in the accommodation cavity, and the electrode assembly 20 is immersed in the electrolyte.

[0085] Optionally, the electrode assembly 20 can comprise an electrode body 21 and an active material layer 22 arranged on the electrode body 21. The electrode assembly 20 can comprise a plurality of electrode bodies 21, and each electrode assembly 20 can comprise two polar plates with opposite polarities in the embodiment of the wound structure, and the two polar plates each comprise an electrode body 21 and an active material layer 22 arranged on the electrode body 21. In the embodiment of the stacked structure, each electrode assembly 20 can comprise a plurality of polar plates stacked in layers, and the polar plates comprise positive polar plates and negative polar plates, and each layer of polar plates comprises an electrode body 21 and an active material layer 22 arranged on the electrode body 21.

[0086] Each active material layer 22 comprises a main body area 221 and a thinned area 222, and the thickness of the active material layer 22 in the thinned area 222 is smaller than the thickness of the active material layer 22 in the main body area 221. Optionally, the electrode body 21 can further comprise a bearing portion for arranging the active material layer 22 and a tab protruding from the bearing portion. The thinned area 222 can be arranged on one side of the main body area 221 close to the tab, so as to reduce the possibility of edge curling of the polar plate caused by baking and casting.

[0087] The thickness of the thinned area 222 in the active material layer 22 is smaller than the thickness of the main body area 221, and optionally, the thickness of the thinned area 222 can gradually decrease in a direction away from the main body area 221, or the thickness of the thinned area 222 can decrease in a stepped manner. At the edge of the thinned area 222, the thickness of the active material layer 22 can decrease to zero, that is, the bearing portion can comprise a region without the active material layer 22 arranged thereon, and the electrode body 21 is exposed outside.

[0088] On this basis, the electrode body 21 and the active material layer 22 are stacked or wound together with the separator to form an electrode assembly 20, which includes a first area 23 and a second area 24, and the two areas are arranged in sequence along the first direction X, that is, the arrangement direction of the main body area 221 and the thinned area 222, the main body area 221 of each active material layer 22 is located in the first area 23, and the thinned area 222 of each active material layer 22 is located in the second area 24, and each thinned area 222 and each main body area 221 can be arranged in a direction perpendicular to the first direction X. Therefore, the thickness of the electrode assembly 20 in the first area 23 is greater than that in the second area 24, and the thickness direction is the second direction Y.

[0089] The battery monomer 100 also has a barrier 30 arranged between the electrode assembly 20 and the inner wall of the shell and extending at least partially along the circumference of the electrode assembly 20. The barrier 30 is arranged corresponding to the second area 24 of the electrode assembly 20 and is used to fill the gap between the electrode assembly 20 and the shell due to the thickness difference between the first area 23 and the second area 24 of the electrode assembly 20.

[0090] Optionally, the side surface of the barrier 30 towards the electrode assembly 20 can match the shape of the outer circumferential surface of the second area 24, so that the two can be closely attached to better fill the gap between the shell and the electrode assembly 20. At the same time, corresponding to the thickness change of the second area 24, in the direction from the first area 23 to the second area 24, the thickness of the barrier 30, that is, the size in the second direction Y, can increase, so as to adapt to the gradually decreasing thickness of the thinned area 222 and further improve the filling effect.

[0091] In the technical scheme of the embodiment, the battery monomer 100 includes a shell, an electrode assembly 20 arranged in the shell, and a barrier 30 arranged around the electrode assembly 20, wherein the electrode assembly 20 includes an electrode body 21 and an active material layer 22 coated on the electrode body 21. Due to the influence of factors such as processing technology, the active material layer 22 usually has a relatively thin thickness at one end close to the tab of the electrode sheet, that is, a main body area 221 and a thinned area 222 are formed, and thus the electrode assembly 20 formed by stacking or winding the electrode sheet also has a first area 23 and a second area 24 with different thicknesses. The barrier 30 is arranged corresponding to the thinned area 222 of the active material layer 22 and can fill the gap formed between the electrode assembly 20 and the shell due to the thickness change of the electrode assembly 20, reduce the possibility of lithium precipitation in the cycle process due to the existence of the gap, and thus improve the cycle performance and prolong the service life of the battery monomer 100.

[0092] Please refer to Figure 7 , Figure 7A partial sectional view of a battery cell is provided for some embodiments of the present application. In some alternative embodiments, along a direction from the second region 24 to the first region 23, the second region 24 comprises a first sub-region 241, a second sub-region 242 and a third sub-region 243 arranged in sequence, and along the second direction Y, the maximum size of the barrier 30 in the first sub-region 241 is L1, the maximum size in the second sub-region 242 is L2, and the maximum size in the third sub-region 243 is L3; L1≥L2≥L3.

[0093] On the basis of the aforementioned thickness variation trend, the second region 24 can be divided into three sub-regions, including a first sub-region 241, a second sub-region 242 and a third sub-region 243 arranged in sequence along a direction from the second region 24 to the first region 23, and the three sub-regions can be arranged in sequence or spaced apart. Corresponding to the electrode assembly 20, the barrier 30 is arranged corresponding to the second region 24 along the second direction Y, and on the basis of being divided into three sub-regions, the barrier 30 can be arranged corresponding to at least one of the sub-regions, and the barrier 30 can be arranged such that the two ends of the barrier 30 extend to the first sub-region 241 and the third sub-region 243 along the first direction X, respectively.

[0094] Further, on the basis of dividing the barrier 30 into three sections corresponding to the first sub-region 241, the second sub-region 242 and the third sub-region 243 respectively, the maximum size in each section corresponding to each sub-region of the barrier 30 can increase in sequence along the first direction X. Specifically, the maximum size in the section of the barrier 30 corresponding to the first sub-region 241 is denoted as L1, the maximum size in the section corresponding to the second sub-region 242 is denoted as L2, and the maximum size in the section corresponding to the third sub-region 243 is denoted as L3, and on the basis of making the size of the barrier 30 increase along a direction from the main region 221 to the thinned region 222, further L1≥L2≥L3.

[0095] By limiting the relative size of the maximum thickness of the barrier 30 in the three sub-regions, the barrier 30 can be at least partially located in the region corresponding to the first sub-region 241, so as to fill the region with a larger gap between the electrode assembly 20 and the shell, thereby reducing the weight and cost of the battery cell 100 while maintaining a certain filling effect. At the same time, by limiting the aforementioned maximum thickness, the thickness of the barrier 30 can change relatively uniformly, so as to adapt to the thickness variation of the electrode assembly 20 and reduce the possibility of damage to the electrode assembly 20 due to extrusion.

[0096] In some alternative embodiments, along the first direction X, the two ends of the barrier 30 extend to the first sub-region 241 and the third sub-region 243, respectively, and the size of the barrier 30 is 7-13 mm.

[0097] The barrier 30 in the embodiments of the present application is arranged corresponding to the second area 24 of the electrode assembly 20. In the embodiments in which the second area 24 is divided into three sub-areas, the barrier 30 can extend to the first sub-area 241 and the third sub-area 243 on both sides in the first direction X, that is, the barrier 30 has a certain extension size in the first direction X, and further can be selected to have the same or similar extension size in the first direction X as the second area 24.

[0098] On this basis, the size of the barrier 30 in the first direction X can be 7mm-13mm, for example, can be selected to be any one of 7mm, 9mm, 11mm, 13mm or between any two of them, thereby reducing the possibility that the barrier 30 is too narrow to cause a gap between the electrode assembly 20 and the shell, and reducing the possibility that the barrier 30 is too wide to cause the space of the first area 23 of the electrode assembly 20 to be squeezed, the weight and cost of the battery monomer 100 to rise, and other problems.

[0099] In some optional embodiments, the first sub-area 241, the second sub-area 242 and the third sub-area 243 are arranged in sequence in the first direction X, the distance between the second sub-area 242 and the side edge of the second area 24 away from the first area 23 is 2mm-4mm, and the distance between the third sub-area 243 and the side edge of the second area 24 away from the first area 23 is 7mm-9mm; in the second direction Y, the size of the electrode assembly 20 in the first area 23 is L4, 0.06≤L1 / L4≤0.1, 0.04≤L2 / L4≤0.06, 0.02≤L3 / L4≤0.03.

[0100] Optionally, in the embodiments in which the second area 24 includes three sub-areas, the three sub-areas can also be arranged in sequence and their positions and sizes can be further limited. Among them, taking the side edge of the second area 24 away from the first area 23 as a reference line, the distance between the second sub-area 242 and the reference line is 2mm-4mm, for example, can be selected to be any one of 2mm, 2.5mm, 3mm, 3.5mm, 4mm or between any two of them. The distance between the third sub-area 243 and the reference line is 7mm-9mm, for example, can be selected to be any one of 7mm, 7.5mm, 8mm, 8.5mm, 9mm or between any two of them.

[0101] Exemplarily, taking the side edge of the second area 24 away from the first area 23 as a reference line, the area with a distance of 0-3mm from the reference line can be the first sub-area 241, the area with a distance of 3mm-8mm from the reference line can be the second sub-area 242, and the area with a distance of 8mm-13mm from the reference line can be the third sub-area 243.

[0102] On this basis, along the second direction Y, the maximum size of the barrier piece 30 in the three sub-zones of the first to third is respectively recorded as L1, L2, L3, and the thickness of the electrode assembly 20 in the first zone 23 is recorded as L4, then L1 / L4 can be selected as 0.06-0.1, for example, can be any one of 0.06, 0.08, 0.1 or between any two of them; L2 / L4 can be selected as 0.04-0.06, for example, can be selected as any one of 0.04, 0.05, 0.06 or between any two of them; L3 / L4 can be selected as 0.02-0.03, for example, can be selected as any one of 0.02, 0.025, 0.03 or between any two of them.

[0103] Further, the thickness size of the barrier piece 30 in the three segments corresponding to the three sub-zones can be within the aforementioned numerical range. It can be understood that, in the embodiment in which the barrier piece 30 is arranged on the opposite sides of the electrode assembly 20 along the second direction Y, the thickness size here refers to the sum of the thickness sizes of the barrier pieces 30 on the two sides.

[0104] By setting the thickness of the barrier piece 30 in each region and the thickness of the electrode assembly 20 in the first zone 23 within the aforementioned numerical range, the thickness size of the barrier piece 30 can be smoothly changed and adapted to the change of the electrode assembly 20, further improving the filling effect of the gap between the electrode assembly 20 and the shell, and further improving the cycle performance.

[0105] Please refer to Figure 8 , Figure 8 The cross-sectional structure schematic diagram of the battery cell provided by some embodiments of the present application is shown. In some optional embodiments, the barrier piece 30 is annular and arranged around the electrode assembly 20; or the barrier piece 30 includes a plurality of first sub-pieces 31, and the plurality of first sub-pieces 31 are arranged in sequence along the circumference of the electrode assembly 20.

[0106] In the embodiment in which the barrier piece 30 is annular and arranged around the electrode assembly 20, the barrier piece 30 can be sleeved on the electrode assembly 20 and has a length size which is the same as or similar to the circumference of the electrode assembly 20, so that it can abut against the outer circumferential surface of the electrode assembly 20. By arranging the barrier piece 30 in a ring shape, it can be convenient to align and install with the electrode assembly 20, and the annular barrier piece 30 can uniformly fill the gap in each direction, further improving the cycle performance of the battery cell 100.

[0107] Alternatively, the barrier 30 can be provided as a plurality of first sub-members 31 arranged along the circumference of the electrode assembly 20. The first sub-members 31 can be provided independently of each other, or the first sub-members 31 can be partially connected to each other by a connecting rope or the like. By providing the barrier 30 as a plurality of first sub-members 31 arranged along the circumference of the electrode assembly 20, the weight of the battery cell 100 can be reduced on the basis of filling the gap between the electrode assembly 20 and the case, and the electrolyte can be brought into contact with the second region 24 of the electrode assembly 20.

[0108] In some alternative embodiments, the barrier 30 is provided in a ring shape, and the inner side surface of the barrier 30 is in abutment with the outer circumferential surface of the second region 24 to press and compress the electrode assembly 20. The barrier 30 is made of an elastic material, and the elastic modulus of the barrier 30 is 0.05 MPa to 1 MPa.

[0109] Alternatively, the barrier 30 can be provided in a ring shape and fitted around the electrode assembly 20, and the barrier 30 can be made of an elastic material. In this embodiment, the length of the barrier 30 in a normal state in which the barrier 30 is not stretched or compressed can be slightly smaller than the outer circumference of the second region 24 of the electrode assembly 20, so that the barrier 30 can apply a pressing and compressing force to the electrode assembly 20 after being fitted around the electrode assembly 20. Thus, the electrode assembly 20 can be compressed while filling the gap between the electrode assembly 20 and the case, and the gap between the electrode plates in the electrode assembly 20 can be reduced, thereby further improving the cycle performance of the battery cell 100.

[0110] On this basis, the elastic modulus of the barrier 30 can be selected to be 0.05 MPa to 1 MPa, for example, 0.05 MPa, 0.07 MPa, 0.09 MPa, 1 MPa, or any value or range between any two of these values. By setting the elastic modulus of the barrier 30 in the above range, the possibility that the barrier 30 is too tight and damages the electrode assembly 20 can be reduced, and the possibility that the barrier 30 is too loose and cannot eliminate the gap in the electrode assembly 20 can be reduced.

[0111] Please refer to Figure 9 , Figure 9 A partial cross-sectional structure of a battery cell according to some embodiments of the present application is shown in the figure. In some alternative embodiments, the barrier 30 is provided in a ring shape, and the size of the barrier 30 in the first direction X is the same as the size of the second region 24. Alternatively, the barrier 30 is provided in a ring shape, and at least part of the barrier 30 includes a plurality of second sub-members 32 arranged along the first direction X.

[0112] Optionally, in the embodiment where the barrier 30 is annular, the barrier 30 can be extended completely in the first direction X and formed into a wider belt structure, so as to correspond to the majority of the area in the second region 24. Further, the extension size of the wider belt barrier 30 in the first direction X can be the same as the extension size of the second region 24.

[0113] By setting the barrier 30 into a wider annular belt structure, the uniformity and reliability of the bound electrode assembly 20 can be improved.

[0114] Alternatively, the barrier 30 can also be set as a plurality of second sub-pieces 32 arranged at intervals along the first direction X, the second sub-pieces 32 being smaller in width size in the first direction X and all located in the area corresponding to the second region 24. The thickness of each second sub-piece 32 itself can gradually increase in the direction from the first region 23 to the second region 24, and the thickness of the plurality of second sub-pieces 32 can gradually increase in the order of their arrangement in the direction, so as to adapt to the thickness variation of the electrode assembly 20.

[0115] By setting the barrier 30 as a plurality of second sub-pieces 32 arranged along the second direction Y, the weight of the battery monomer 100 can be reduced.

[0116] In some optional embodiments, the barrier 30 includes a plurality of first sub-pieces 31 arranged at intervals along the circumference of the electrode assembly 20, and the opposite side surfaces of each first sub-piece 31 are respectively in abutment with the electrode assembly 20 and the shell.

[0117] In the embodiment where the barrier 30 includes a plurality of first sub-pieces 31 and the first sub-pieces 31 extend along the circumference of the electrode assembly 20, the thickness size of the first sub-pieces 31 sandwiched between the shell and the electrode assembly 20 can be adjusted according to the size of the shell and the size of the electrode assembly 20, so that the opposite side surfaces of the plurality of first sub-pieces 31 can be respectively in abutment with the shell and the electrode assembly 20, thereby transmitting the binding and extruding force to the electrode assembly 20.

[0118] Specifically, the side surface of the first sub-piece 31 facing the shell can be optionally a flat surface adapted to the inner wall of the shell, and the side surface of the first sub-piece 31 facing the electrode assembly 20 can be optionally an inclined flat surface or an inclined arc surface adapted to the thickness variation of the electrode assembly 20. The aforementioned two surfaces of the first sub-piece 31 are respectively in abutment with the shell and the electrode assembly 20, thereby being able to extrude the electrode assembly 20 inward while filling the gap, so as to reduce the gap between the pole pieces inside the electrode assembly 20 and further improve the cycle performance of the battery monomer 100.

[0119] Please refer to Figure 10 , Figure 10A schematic diagram of a cross-sectional structure of a battery cell is provided for some embodiments of the present application. In some alternative embodiments, the battery cell 100 comprises a plurality of electrode assemblies 20 and a plurality of barrier pieces 30, the plurality of electrode assemblies 20 and the plurality of barrier pieces 30 are arranged one by one.

[0120] To improve the capacity of the battery cell 100, in the embodiment in which the electrode assembly 20 is made in a winding manner, a plurality of electrode assemblies 20 can be arranged in the housing of the same battery cell 100, and these electrode assemblies 20 can be arranged in sequence along the second direction Y, i.e., the thickness direction. Correspondingly, a plurality of barrier pieces 30 can be arranged in the battery cell 100, and each barrier piece 30 is arranged one by one with each electrode assembly 20 to respectively fill the gaps and apply a force to the electrode assembly 20.

[0121] Specifically, in the embodiment in which the barrier piece 30 is annular and is sleeved on the electrode assembly 20, each barrier piece 30 can be sleeved on each electrode assembly 20, and the two barrier pieces 30 sleeved on the adjacent two electrode assemblies 20 can be arranged in abutment with each other. Alternatively, the plurality of barrier pieces 30 can be connected or integrally formed according to the size and position of the electrode assembly 20 to further provide the function of auxiliary fixation.

[0122] In the embodiment in which the barrier piece 30 comprises a plurality of first sub-pieces 31 arranged at intervals along the circumferential direction of the electrode assembly 20, the first sub-pieces 31 located between the two electrode assemblies 20 can be connected or integrally arranged, i.e., the plurality of first sub-pieces 31 located between the two electrode assemblies 20 and arranged corresponding to the two electrode assemblies 20 form an integral structure, and the opposite side surfaces of the structure can be in abutment with the two electrode assemblies 20, so that the arrangement position of the first sub-piece 31 is more stable.

[0123] In some alternative embodiments, the material of the barrier piece 30 comprises polyethylene terephthalate (PET).

[0124] Alternatively, the barrier piece 30 can be made of PET (polyethylene terephthalate), and the PET material has excellent electrical insulation and still has good electrical properties and dimensional stability under high temperature and high frequency. By arranging the barrier piece 30 to be made of PET material, the barrier piece 30 can have higher reliability and stable shape and size.

[0125] In a second aspect, the battery device 200 according to the embodiments of the present application is provided, which comprises a box 40 and the battery cell 100 in any of the embodiments of the first aspect, and the battery cell 100 is arranged in the box 40.

[0126] In a third aspect, the application provides a power consuming device, comprising the battery device 200 in any of the embodiments of the second aspect, and the battery device 200 is configured to provide electric energy.

[0127] The battery device 200 and the power consuming device in the embodiments of the application have all the beneficial effects of the battery cell 100 in the first aspect, and specific descriptions can be made with reference to the specific descriptions of the battery cell 100 in the above embodiments. The present embodiment will not be repeated here.

[0128] The application provides a battery cell 100, comprising a shell, an electrode assembly 20, and a barrier 30; the electrode assembly 20 is arranged in the shell, and the electrode assembly 20 comprises an electrode body 21 and an active material layer 22 arranged on the electrode body 21, the active material layer 22 comprises a main body area 221 and a thinning area 222 arranged along a first direction X, the thickness of the active material layer 22 in the main body area 221 is greater than the thickness of the active material layer 22 in the thinning area 222, the electrode assembly 20 comprises a first area 23 and a second area 24 arranged along the first direction X, the main body area 221 is located in the first area 23, and the thinning area 222 is located in the second area 24; the barrier 30 is arranged between the second area 24 and the shell and extends at least partially along the circumference of the electrode assembly 20, and in the direction from the first area 23 to the second area 24, the thickness of the barrier 30 in a second direction Y shows an increasing trend, and the first direction X intersects the second direction Y.

[0129] The barrier 30 is annularly arranged, and the inner side surface of the barrier 30 abuts against the outer circumferential surface of the second area 24 to extrude and compress the electrode assembly 20; the barrier 30 is made of an elastic material, and the elastic modulus of the barrier 30 is 0.05 MPa-1 MPa.

[0130] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application, and they should be covered in the scope of the claims and the description of the application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: case; An electrode assembly is disposed in the housing. The electrode assembly includes a plurality of electrode bodies and an active material layer disposed on the electrode bodies. The active material layer includes a main body region and a thinning region arranged along a first direction. The thickness of the active material layer in the main body region is greater than the thickness in the thinning region. The electrode assembly includes a first region and a second region arranged along the first direction. The main body region is located in the first region, and the thinning region is located in the second region. A barrier element is disposed between the second region and the housing and extends at least partially along the circumferential direction of the electrode assembly. The thickness of the barrier element increases in a second direction from the first region to the second region, and the first direction intersects the second direction.

2. The battery cell according to claim 1, characterized in that, Along the direction from the second region to the first region, the second region includes a first sub-region, a second sub-region, and a third sub-region arranged in sequence. In the second direction, the maximum size of the barrier in the first sub-region is L1, the maximum size in the second sub-region is L2, and the maximum size in the third sub-region is L3. L1≥L2≥L3.

3. The battery cell according to claim 2, characterized in that, Along the first direction, the two ends of the barrier extend to the first sub-region and the third sub-region, respectively, and the size of the barrier is 7mm-13mm.

4. The battery cell according to claim 3, characterized in that, The first sub-region, the second sub-region, and the third sub-region are connected in the first direction. The distance between the second sub-region and the edge of the second region away from the first region is 2mm-4mm, and the distance between the third sub-region and the edge of the second region away from the first region is 7mm-9mm. In the second direction, the size of the electrode assembly in the first region is L4, 0.06≤L1 / L4≤0.1, 0.04≤L2 / L4≤0.06, 0.02≤L3 / L4≤0.

03.

5. The battery cell according to any one of claims 1-4, characterized in that, The barrier is annular and surrounds the electrode assembly; Alternatively, the barrier may include a plurality of first sub-components arranged sequentially along the circumference of the electrode assembly.

6. The battery cell according to claim 5, characterized in that, The barrier is arranged in a ring shape, and the inner side of the barrier abuts against the outer peripheral surface of the second region to compress and tighten the electrode assembly. The barrier is made of an elastic material with an elastic modulus of 0.05 MPa to 1 MPa.

7. The battery cell according to claim 5, characterized in that, The barrier is arranged in a ring shape, and along the first direction, the size of the barrier is the same as the size of the second area; Alternatively, the barrier is arranged in a ring shape, and at least a portion of the barrier includes a plurality of second sub-components, which are spaced apart in the first direction.

8. The battery cell according to claim 5, characterized in that, The barrier includes a plurality of first sub-components, which are spaced apart circumferentially along the electrode assembly, and the opposite side surfaces of each first sub-component abut against the electrode assembly and the housing, respectively.

9. The battery cell according to claim 1, characterized in that, The battery cell includes multiple electrode assemblies and multiple barrier components, with each electrode assembly and barrier component corresponding to the other one-to-one.

10. The battery cell according to claim 1, characterized in that, The material of the barrier includes polyethylene terephthalate.

11. A battery device, characterized in that, include: Box; A plurality of battery cells as described in any one of claims 1-10, wherein the battery cells are disposed in the housing.

12. An electrical appliance, characterized in that, Includes the battery device as described in claim 11, the battery device being used to provide electrical energy.

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